D4001 - 13 Standard Test Method for Determination of Weight-Average Molecular Weight of Polymers By Light Scattering , light scattering, polymers, weight-average molecular weight,
In this work, we present a generalization of our previous model, which allows us to account for the entire molecular weight distribution, as well as the long-chain branching. We develop a deeper insight into the vinyl group distribution among the molecules given the operating conditions of the modification process. We focus on the modification taking place in a press at constant temperature, under conditions where scission is not measurable. II. MATHEMATICAL MODEL We develop a set of mass balances for the reacting species where the different lengths, number of vinyls and number of branching points are taken into account. A triple moment technique was used to calculate number and weight average molecular weights as well as average number of branching points for species having j vinyls, j=0, 1, 2 To calculate molecular weight distributions we apply another transform technique that makes use of probability generating function (pgf) definitions applied to the number and weight MWD, following the ...
The influence of molecular weight distribution and extrusion processing variables on the morphological features and orientation of high density polyethylene (HDPE) uniaxially extruded tubular films was investigated. In order to gain a better understanding of the orientation-crystallization behavior occurring during extrusion processing, the melt flow properties of the two HDPE resins with identical (14 600) values but different molecular weight distributions (/ = 10.3, 15.1), utilized in our previous study, were characterized by dynamic rheological experiments over the temperature range from 150 degrees C to 230 degrees C within the angular frequency range from 0.1 to 100 rad/s. The experimental data were shifted to produce master flow curves. The how activation energy calculated from the shifting process was found to be 25.9 kJ/mol for resin 1 and 29.1 kJ/mol for resin 2. The characteristic relaxation time at 190 degrees C obtained by use of a ...
Extractable dietary fiber (DF) plays an important role in nutrition. This study on porridge making with whole grain rye investigated the effect of rest time of flour slurries at room temperature before cooking and amount of flour and salt in the recipe on the content of DF components and molecular weight distribution of extractable fructan, mixed linkage (1→3)(1→4)-β-D-glucan (β-glucan) and arabinoxylan (AX) in the porridge. The content of total DF was increased (from about 20% to 23% of dry matter) during porridge making due to formation of insoluble resistant starch. A small but significant increase in the extractability of β-glucan (P = 0.016) and AX (P = 0.002) due to rest time was also noted. The molecular weight of extractable fructan and AX remained stable during porridge making. However, incubation of the rye flour slurries at increased temperature resulted in a significant decrease in extractable AX molecular weight. The molecular weight of extractable β-glucan decreased greatly during
Macrophage suppression has been shown to be mediated by a unique, low molecular weight fraction of murine serum. The present investigation involves the in vitro production of this macrophage modulator (suppressor) by Concanavalin A-stimulated spleen cells. Spleen cell culture supernatant containing macrophage suppressor factor (MSF) caused a significant decrease in in vitro phagocytosis of Listeria monocytogenes by non-elicited peritoneal macrophages. The molecular weight of MSF was determined by ultrafiltration to be less than 10,000, and the modulating activity of MSF was not altered by heating at 100°C for 30 minutes or freezing at -70°C for six months. MSF is resistant to treatment with Pronase E, but is, however, sensitive to acid hydrolysis. Activity of MSF in spleen cell culture supernatants from normal mice does not differ from supernatants from mice immunized with L. monocytogenes. It was therefore concluded that MSF is not affected by antigenic stimulation and is apparently produced
In this study, we show how the combining an ACQUITY Advanced Polymer Chromatography (APC) System combined with a 2414 Refractive Index (RI) Detector and ACQUITY QDa Mass Detector can be used to simultaneously measure polymer molecular weight distribution and polymer additive detection.
TY - JOUR. T1 - Extended Fujita approach to the molecular weight distribution of polysaccharides and other polymeric systems. AU - Harding, Stephen E.. AU - Schuck, Peter. AU - Abdelhameed, Ali Saber. AU - Adams, Gary. AU - Kök, M. Samil. AU - Morris, Gordon A.. PY - 2011/5. Y1 - 2011/5. N2 - In 1962 H. Fujita (H. Fujita, Mathematical Theory of Sedimentation Analysis, Academic Press, New York, 1962) examined the possibility of transforming a quasi-continuous distribution g(s) of sedimentation coefficient s into a distribution f(M) of molecular weight M for linear polymers using the relation f(M)=g(s)·(ds/dM) and showed that this could be done if information about the relation between s and M is available from other sources. Fujita provided the transformation based on the scaling relation s=κsM0.5, where κs is taken as a constant for that particular polymer and the exponent 0.5 essentially corresponds to a randomly coiled polymer under ideal conditions. This method has been successfully ...
TY - JOUR. T1 - Molecular weight distribution of proteins synthesized in single, identified neurons of Aplysia. AU - Wilson, David L.. PY - 1971/1/1. Y1 - 1971/1/1. N2 - Parietovisceral ganglia from Aplysia californica were incubated in medium containing leucine-8H. Single, identified nerve cell somas were isolated from the ganglia, and their proteins extracted and separated by electrophoresis on 5 % SDS-polyacrylamide gels. The distribution of total or newly synthesized proteins from the single neurons was determined by staining or slicing and liquid scintillation counting of the gels. Experiments showed that: (a) a number of proteins were being synthesized in abundance in the nerve cells; (b) different, identified neurons showed reproducibly different labeling patterns in the gels; (c) cells R2 and R15, which showed different distributions of radioactivity in the gels, had similar staining patterns; and (d) there was significant incorporation into material of high (, 75,000) molecular weight ...
Four size exclusion chromatography (SEC) calibration techniques were tested for use in the molecular weight characterisation of Streptococcal Hyaluronic Acid (HA). An exponential equation, evaluated using the Hamielec method, was superior to the customary peak position method. It provided the most accurate estimates of the weight average molecular weight, Mw. The calibration was valid for HA in the range 800 - 2500 kDa, and permitted the calculation of both polydispersity and molecular weight distributions for HA from Streptococcal fermentations. This exponential calibration approach should have application in the characterisation of other large biopolymers, particularly where pore size of available SEC media is limiting ...
A mathematical model is developed for the molecular weight distribution (IMWD) of a polyethylene terephthalate (PET) polycondensation process based on the reaction mechanisms and the operating conditions. It employs the logical combination of the reaction extent method, the moment method and the statistical fitting technique. An optimization scheme is then discussed on the tracking of the desired MWD during the polymerization process.. ...
A method to evaluate molecular weight distribution (MWD) from dynamic moduli is presented here. It relies on the least-square fitting of the dynamic data to a model whose parameters depend on the...
This research is focused on the polymerization of 2-alkyl-2-oxazoline homopolymers and 2-alkyl-2-oxazoline containing copolymers with well-defined structures. In addition, the potential of selected materials as polymer blend compatibilizers was briefly evaluated. The polymerization of 2-alkyl-2-oxazoline was investigated with regard to the effects of initiator structures on molecular weight control and molecular weight distribution, living characteristics, and mechanisms and kinetics. The structure of initiators was shown to greatly affect the molecular weight control and molecular weight distribution of poly (2-ethyl-2-oxazoline). The living nature of poly (2-ethyl-2-oxazoline) in chlorobenzene initiated by benzyl iodide, benzyl chloride/NaI, or chloroethyl ethyl ether/NaI has been established by Mn-conversion plots and sequential monomer addition experiments. However, the molecular weight distributions of these polymers were not as narrow as Poisson distributions, Mechanistic and kinetic ...
TY - CONF. T1 - Assessment of Small molecular weight inhibitors of the contact phase. AU - Bouckaert, Charlotte. AU - Zhu, Shu. AU - Diamond, Scott. AU - Pochet, Lionel. PY - 2016/5/27. Y1 - 2016/5/27. M3 - Other. Y2 - 25 May 2016 through 28 May 2016. ER - ...
Matossian, rogers A.; Rogers, P; Ledbetter, J A.; and Herzenberg, L A., Molecular weight determination of two genetically linked cell surface murine antigens: thb and ly-6. (1982). Subject Strain Bibliography 1982. 534 ...
A process for producing a thermoplastic polymer composition comprising: (1) 100 parts by weight of an olefin polymer which comprises ethylene and at least one α-olefin having 3 to 10 carbon atoms and in which the density is in the range of 0.85 to 0.91 g/cm3 and the molecular weight distribution (Mw/Mn) which is the ratio of weight average molecular weight (Mw) and number average molecular weight (Mn) as calculated by a gel permeation chromatography (GPC) is less than 3.5, (2) 5 to 300 parts by weight of a propylene polymer, (3) 5 to 250 parts by weight of an oil, and (4) 0.02 to 3 parts by weight of a radical initiator, which process comprises steps of previously mixing and heat-kneading the olefin polymer, the propylene polymer and the radical initiator; adding the oil in the stage in which cross-linking is at a proportion of 30 to 95% based on the cross-linking degree of the composition to be finally obtained; and further melt-kneading them to cross-link the same.
Summary of Facts and Submissions. I. European patent No. 1 328 591, filed as application number 01 974 468.9, based on the international application published as WO 02/33008, was granted on the basis twenty-three claims. Claim 1 as granted reads as follows (emphasis added):. 1. An aqueous coating composition comprising:. an ambient temperature crosslinkable water-dispersible polyester oligomer(s) less than 80% by weight soluble in water throughout the pH range of from 2 to 10, with a measured weight average molecular weight in the range of from 1,000 to 100,000 Daltons; and. a dispersed polymer(s) which is not a polyester oligomer, the dispersed polymer(s) having a lower limit of 10% by weight, with a measured weight average molecular weight ,=120,000 Daltons;. wherein said composition when drying to form a coating has the following properties:. i) an open time of at least 20 minutes at 23±2ºC;. ii) a wet edge time of at least 10 minutes at 23±2ºC;. iii) a thumb hard time of ,=48 hours at ...
A high solids coating composition useful as a clear coat for an automotive clear coat/color coat finish which contains about 40-80% by weight of a binder and correspondingly about 20-60% by of a liquid organic carrier; wherein the binder contains about: a. an acrylic solution polymer of polymerized monomers of ethylenically unsaturated esters of acrylic acid or methacrylic acid and a hydroxy alkyl acrylate or methacrylate and the polymer has a hydroxyl no. of about 50-200 and a weight average molecular weight of about 4,000-20,000; b. a dispersed polymer of polymerized monomers having stabilizer resin segment that is soluble in the organic carrier and dispersed resin segment that is relatively insoluble in the organic carrier; c. a siloxane oligomer having --OH and --OR groups attached to the silane atoms of the oligomer where R is an alkyl group having 1-6 carbon atoms in the alkyl group or an aryl group and the oligomer has a weight average molecular weight of about 500-5,000; and d. an alkylated
Acetone powders prepared from leaf extracts of Tecoma stans L. were found to catalyze the oxidation of catechol to 3,4,3,4-tetrahydroxydiphenyl. Fractionation of the acetone powders obtained from Tecoma leaves with acetone, negative adsorption of the acetone fraction with tricalcium phosphate gel, and chromatography of the gel supernatant on DEAE-Sephadex yielded a 68-fold purified enzyme with 66% recovery. The enzyme had an optimum pH around 7.2. It showed a temperature optimum of 30° and the Km for catechol was determined as 2 x 10-4 m. The purified enzyme moved as a single band on polyacrylamide gel electrophoresis. Its activity was found to be partially stimulated by Mg2+. The reaction was not inhibited by o-phenanthroline and agr,agr-dipyridyl. The purified enzyme was highly insensitive to a range of copper-chelating agents. It was not affected appreciably by thiol inhibitors. The reaction was found to be suppressed to a considerable extent by reducing agents like GSH, cysteine, ...
The invention provides a polymerization process comprising polymerizing a reaction mixture comprising one or more monomer types, at least one catalyst, and at least one solvent, to form a polymer dispersion, and wherein the at least one catalyst is soluble in the at least one solvent, and wherein the polymer forms a dispersed phase in the solvent, and wherein the at least one solvent is a hydrocarbon. The invention provides a composition comprising an ethylene-based polymer comprising at least the following properties: a) a weight average molecular weight (Mw(abs)) greater than, or equal to, 60,000 g/mole; and b) a molecular weight distribution (Mw(abs)/Mn(abs)) greater than, or equal to, 2.3.
How is Viscosity Average Molecular Weight abbreviated? VAMW stands for Viscosity Average Molecular Weight. VAMW is defined as Viscosity Average Molecular Weight very rarely.
As a professional reliability third-party testing organization, T,C&A Lab can provide Molecular Weight Analysis service according related standards and industry requirements.
Sulfated low molecular weight lignins (LMWLs) have shown good activity as anticoagulants by allosterically inhibiting thrombin, as well as promising agents for treating emphysema through inhibition of elastolysis, oxidation, and inflammation. Sulfated LMWLs are chemo-enzymatically synthesized from starting monomers caffeic, ferulic, and sinapic acid into sulfated dehydropolymers known as CDS, FDS, and SDS. To further the LMWLs development as drugs, their structural composition and physicochemical characteristics were defined in this work. The molecular weight distribution profile of the sulfated LMWLs from size exclusion chromatography performed on a high pressure liquid chromatography system (SEC-HPLC) changed from bimodal when no surfactant is used in the mobile phase of the HPLC to unimodal when surfactant is used in the mobile phase. This indicates that some large molecular weight species, likely an aggregate of smaller molecular weight chains, are disrupted when surfactant is present. The
Fingerprint Dive into the research topics of Generation of well-relaxed all-atom models of large molecular weight polymer melts: A hybrid particle-continuum approach based on particle-field molecular dynamics simulations. Together they form a unique fingerprint. ...
The [35S]methionine-labeled proteins released in the medium conditioned by normal and transformed mouse fibroblasts have been analyzed by sodium dodecyl sulfate-polyacrylamide electrophoresis. Three major proteins, fibronectin, procollagens, and a protein with a molecular weight of 45,000 (45K protein) have been identified. The 45K protein, which has not yet been described, accounts for about 30% of the proteins released by control 3T3 fibroblasts or mouse embryo cultures. Quantitation of the radioactivity incorporated by the 45K protein indicated a 10- to 15-fold decrease in 3T3 fibroblasts transformed by Kirsten, Abelson, or Rous sarcoma viruses. The amounts of fibronectin and procollagens released in the medium by transformed cells were also reduced by factors of 3- and 5-fold, respectively. Pulse chase experiments have shown that the decreased level of the 45K protein in the medium of transformed cells cannot be explained by a reduced rate of secretion or by extracellular proteolytic ...
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Dahl, H M.; Truelsen, E; and Blair, G E., The purification and properties of two low-molecular-weight proteins required for the initiation of translation in ascites tumour cells. (1977). Subject Strain Bibliography 1977. 1411 ...
A first step in characterizing a protein often involves determining its molecular weight. From this information, different proteins may be compared and the number of amino acid residues in a protein can be determined. Here, students determine the molecular weight of two unknown proteins by comparing their electrophoretic migration with the migration of standard proteins. The protein standards and unknowns have been pre-stained so that your students can follow ...
Multilayer thermoplastic film structures comprising at least one heat-sealable outer layer (A) and at least one core layer (B) are disclosed. Layer (A) has improved heat sealability after irradiation (e.g. electron beam). Layer (B) has improved shrinkage after irradiation. Layer (A) is a linear polyethylene having a melt index from about 2 to about 20 g/10 minutes, a density from about 0.88 to about 0.92 g/cc, a molecular weight distribution (I10 /I2) from about 5 to about 8, a fraction of the polyethylene having a degree of branching less than or equal to 2 methyls/1000 carbons of not more than 15% by weight and a fraction of the polyethylene having a degree of branching greater than or equal to 25 methyls/1000 carbons of not more than 25% by weight of the polymer. Layer (B) is a linear polyethylene having a melt index from about 0.05 to about 5 g/10 minutes, a density from about 0.88 to about 0.94 g/cc and a molecular weight distribution (I10 /I2) from about 8 to about 30.
This research investigated the relationships between molecular size and the TOC, TTHM, acid strength and color concentrations present in raw and coagulated water from Lake Washington. Three separate coagulants were utilized for investigation. There were: Al, Fe and Mg. Results indicated that the majority of the TOC, color and TTHM precursors were in the colloidal size range and removed by coagulation. The remaining TTHM precursors are mostly molecular and require a process other than coagulation for removal from the potable water before environmental standards are met.
The process of the present invention may be used to prepare homopolymers of ethylene and copolymers of ethylene and higher alpha olefins having densities in the range of, for example, about 0.900-0.970 g/cm3 and especially 0.910-0.965 g/cm3; the polymers of higher density e.g. about 0.960 and above being homopolymers. Such polymers may have a melt index, as measured by the method of ASTM D-1238, condition E, in the range of for example, 0.1-200 dg/min, typically from about 0.1 to 150 dg/min., and especially in the range of about 0.1 to 120 dg/min. The polymers may be manufactured with narrow or broad molecular weight distribution. For example, the polymers may have a stress exponent, a measure of the molecular weight distribution, in the range of about 1.1-2.5 and especially in the range of about 1.3-2.0. Stress exponent is determined by measuring the throughput of a melt indexer at two stresses (2160 g and 6480 g loading) using the procedures of the ASTM melt index test method, and the ...
Summary of Facts and Submissions. I. The appeal lies against the decision of the opposition division posted on 25 January 1016 revoking European patent No. 1 453 911.. II. The decision of the opposition division to revoke European patent EP 1 453 911 was based on the claims as granted as the main request, on the first to eighth auxiliary requests filed with letter of 15 October 2015 and on the ninth auxiliary request filed during the oral proceedings before the opposition division on 15 December 2015.. Claim 1 of the main request read:. 1. A process for the preparation of polyethylene resins having a narrow molecular weight distribution that comprises essentially the steps of:. (i) providing a first metallocene-produced linear low density polyethylene (mLLDPE) resin having a density of from 0.920 to 0.940 g/cm**(3)_a MI2 of from 0.05 to 2 g/10 min and a molecular weight distribution in the range of from 2 to 4.5;. (ii) providing a second high density polyethylene (HDPE) prepared either with a ...
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The HPSEC-RI elution profiles of ethanol precipitated WE-AX isolated from flours and breads are shown in Fig. 3. The high molecular weight (HMW). polysaccharides present in the endosperm flours of population rye cultivars (Amilo, Diament and Kier) eluted as the single, sharp and symmetric populations in the high molar mass range of the column (11-14 ml). click here Amongst endosperm flour AX of hybrid rye cultivars, only polymers isolated from Koko cultivar had a similar distribution pattern to those of population ryes, with slightly broader distribution. The remaining profiles of AX from endosperm flour of hybrid cultivars (Stach and Konto) and from wholemeals of population cultivars, apart from the HMW populations also contained the low molecular weight (LMW) polymers, eluting at 14.5-17.5 ml. The high-symmetry peaks of endosperm flour AX (Amilo, Diament, Kier and Koko) were ascribed to their highest weight-average molecular weights (Mw) and intrinsic viscosity ([η]) ( Table 2). While, the ...
A graft polymer containing a cyclic structure comprised of a polymer containing a cyclic structure graft-modified with an unsaturated compound containing a polar group, having a graft ratio of 10 to 150 mol %, having a weight average molecular weight of 1,000 to 1,000,000, and having a gel content of not more than 0.1 wt % or having a ratio (Ha/La) of high molecular weight side area (Ha) and low molecular weight side area (La) divided by a vertical line suspended from a peak top of a differentiated elution profile measured by gel permeation chromatography to a baseline of not more than 1.6, a method of production of the same, and a curable composition containing that graft polymer containing a cyclic structure and a curing agent.
The precursor proteins to the subunits of ubiquinol:cytochrome c reductase (cytochrome bc1 complex) of Neurospora crassa were synthesized in a reticulocyte lysate. These precursors were immunoprecipitated with antibodies prepared against the individual subunits and compared to the mature subunits immunoprecipitated or isolated from mitochondria. Most subunits were synthesized as precursors with larger apparent molecular weights (subunits I, 51,500 versus 50,000; subunit II, 47,500 versus 45,000; subunit IV (cytochrome c1), 38,000 versus 31,000; subunit V (Fe-S protein), 28,000 versus 25,000; subunit VII, 12,000 versus 11,500; subunit VIII, 11,600 versus 11,200). Subunit VI (14,000) was synthesized with the same apparent molecular weight. The post-translational transfer of subunits I, IV, V, and VII was studied in an in vitro system employing reticulocyte lysate and isolated mitochondria. The transfer and proteolytic processing of these precursors was found to be dependent on the mitochondrial ...
TY - GEN. T1 - An experimental approach of the effects of molecular weight on flow-induced crystallization. AU - Swartjes, F.H.M.. AU - Peters, G.W.M.. AU - Rastogi, S.. AU - Meijer, H.E.H.. N1 - Conference code: 15. PY - 1999. Y1 - 1999. M3 - Conference contribution. BT - Polymer Processing Society : annual meeting, 15th, s-Hertogenbosch, The Netherlands, May 31 - June 4, 1999 : proceedings. A2 - Anderson, P.D.. A2 - Kruijt, P.G.M.. PB - Polymer Processing Society. T2 - 15th Annual Meeting of the Polymer Processing Society (PPS-15). Y2 - 31 May 1999 through 4 June 1999. ER - ...
Nurkhamidah, S. and Woo, E. M. (2011), Effects of crystallinity and molecular weight on crack behavior in crystalline poly(L-lactic acid). J. Appl. Polym. Sci., 122: 1976-1985. doi: 10.1002/app.34021 ...
Aqueous coating compositions consist essentially of: (a) a water-insoluble film-forming polymeric resin; (b) water-insoluble agglomerated particulate beads of urea, melamine or phenol and formaldehyde; (c) polyethers having the formulaH(OC.sub.x H.sub.2x).sub.n OHwhere x is from 2 to 4 and n is a number such that the polyether has a weight average molecular weight of from about 200 to about 1000; (d) pigments; and (e) water. The aqueous coating compositions are especially useful for imparting to metal coil a low gloss pigmented protective finish having good metal marking resistance.
Lipscomb, D.L.; Boudreaux, M.K.; Paxton, R.; Spano, J.; Welles, E.G.; Schumacher, J., 1997: Identification of thrombospondin as a high molecular mass protein released from activated equine platelets
Yang J.K., Epstein W.. Adenylate cyclase of Escherichia coli K12 has been purified 17,000-fold to near homogeneity from a 5-fold overproducing strain. One major band of Mr = 92,000 and several minor bands are seen on sodium dodecyl sulfate-polyacrylamide electrophoresis of the purest fractions. Identification of the enzyme with the 92,000-Da protein is based on the correlation of this band with activity when highly purified enzyme is eluted from ADP-sepharose columns. The native enzyme has a molecular weight of 95,000 determined by gel filtration, showing that the enzyme is active as a monomer. The purest enzyme has a specific activity of 700 nmol min-1 mg-1, indicating a turnover number of about 100 min-1. Our data indicate that there are only about 15 molecules of the enzyme in wild type cells of E. coli. In crude extracts, over 80% of the activity is soluble after centrifugation at 100,000 x g, indicating the enzyme is soluble or, at most, loosely membrane bound. The enzyme is only moderately ...
In analysis, our results show an unreasonable result. The majority of the failure is from the volume result. From Avogrados law we know that. As such, because the average volume (0.051 L) was low, the mol resulting from it is also low. A small mol results in a large Mr value, or in our case the Mr of Oxygen is too high.. -Another point to that is that if the experiment was assuming r.t.p, our results prove to be incorrect again. If we compared the mol, the actual mol results of andusing the ideal gas laws is different than if we calculated using normal Stoichiometry.. From Stoichiometry, the actual mol of is, and if we compared it to a ratio of 2:2, the actual mol value of is also 0.138 mol. However in our experiment using the gas law, our mol result was. Again this is due to the fact of the low amount of volume recorded.. -In addition to that point, from the section to: Calculate molar mass of Water using the mass of Hydrogen Peroxide , another flaw to the experiment was the amount of ...
The [35S]methionine-labeled proteins released in the medium conditioned by normal and transformed mouse fibroblasts have been analyzed by sodium dodecyl sulfate-polyacrylamide electrophoresis. Three major proteins, fibronectin, procollagens, and a protein with a molecular weight of 45,000 (45K protein) have been identified. The 45K protein, which has not yet been described, accounts for about 30% of the proteins released by control 3T3 fibroblasts or mouse embryo cultures. Quantitation of the radioactivity incorporated by the 45K protein indicated a 10- to 15-fold decrease in 3T3 fibroblasts transformed by Kirsten, Abelson, or Rous sarcoma viruses. The amounts of fibronectin and procollagens released in the medium by transformed cells were also reduced by factors of 3- and 5-fold, respectively. Pulse chase experiments have shown that the decreased level of the 45K protein in the medium of transformed cells cannot be explained by a reduced rate of secretion or by extracellular proteolytic ...
HSP25 is a member of the ubiquitous family of small heat shock proteins belonging to the big class of stress proteins. It is related to acquiring of cellular thermotolerance, can act as molecular chaperone, is able to inhibit polymerization of actin in vitro and can form high molecular weight complexes. In this thesis the isolation, structural and functional characteri-zation of this protein as well as its abundance in different tissues of rats suffering on patho-logical forms of hypertension is analyzed: · A method for rapid isolation of HSP25 out of Ehrlich-ascites-tumor (EAT) was estab-lished. From isolated HSP25 low and high molecular weight material could be obtained. · Analysis of high molecular weight complexes by means of electron microscopy and ana-lytical ultracentrifugation results in a structural model characterized by a cylindrical structure composed of four stacked rings each containing eight HSP25 monomers. · High-molecular weight complexes of recombinant HSP25 are organized as ...
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VisiBlot Standard I is a mixture of 10 recombinant proteins of a molecular weight range from 25 kDa to 150 kDa. Protein bands of 25 kDa, 45 kDa and 85 kDa are prestained allowing monitoring of protein separation during SDS PAGE. The remaining five proteins contain several IgG binding sites. Hence marker proteins bind to primary or secondary antibodies used in Western Blotting facilitating easy marker visualization on the transfer membrane. Because the proteins have no chromophore attached, the marker enables accurate molecular weight estimation. Recommended loading volume for a mini gel is 5 µl/lane. Ready-to-use, no reconstitution, further dilution or heating required Prestained bands for monitoring electrophoresis and membrane transfer Visualization of marker proteins on Western Blots by horseradish peroxidase or alkaline phosphatase-based immune-detection methods Molecular weight determination of proteins detected on transfer membrane
The molar mass of CuNO_3 is 125.55 g/mol Based on the formula youve given me, that compound would actually be copper (II) nitrate. Copper (I) nitrate is CuNO_3 Before we begin heres a tip: atomic weight of element xxnumber of atoms given by subscript = molar mass First, you want to have your handy dandy periodic table available so you can determine the atomic weight of Cu, N, O Cu has an atomic weight of 63.55 g/mol N has an atomic weight of 14.01 g/mol O has an atomic wight of 16.00 g/mol Based on the chemical formula, we have 1 atom of Cu, which would have an atomic weight of 63.55 g/mol Next, we have 1 atoms of N, and that has an atomic mass of 14.01 g/mol You have 3 atoms of O so we would multiply the atomic mass of O by 3 to obtain 48.00 g/mol. Now you want to add the mass of each atom together to obtain the molecular weight of the entire compound: 63.55 g/mol + 14.01 g/mol + 48.00 g/mol = 125.55 g/mol
Staff publications is the digital repository of Wageningen University & Research. Staff publications contains references to publications authored by Wageningen University staff from 1976 onward.. Publications authored by the staff of the Research Institutes are available from 1995 onwards.. Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.. We have a manual that explains all the features ...
Alison Leakey wrote: , , How do I concentrate a low molecular weight protein (less than 5kDa) , from gel filtration fractions ie. dilute???, keeping in mind that , filtration devices and dialysis tubing concentrate above this size. Have you tried concentrating chromatographic techniques (reverse phase chromatography, ion exchange ...
Browse professional translators on TM-Town in the field of Sodium Dodecylsulfate-Polyacrylamide Gel Electrophoresis and language pair of Danish to Hungarian including the top 10 translators by translation units
TY - JOUR. T1 - Controlling alginate gel degradation utilizing partial oxidation and bimodal molecular weight distribution. AU - Boontheekul, Tanyarut. AU - Kong, Hyun Joon. AU - Mooney, David J.. N1 - Funding Information: The author would like to thank NIDCR/NIH for financial support (RO1 DE13349), as well as Royal King Anandamahidol foundation (Thailand) for a graduate fellowship to T.B.. PY - 2005/5. Y1 - 2005/5. N2 - Degradability is often a critical property of materials utilized in tissue engineering. Although alginate, a naturally derived polysaccharide, is an attractive material due to its biocompatibility and ability to form hydrogels, its slow and uncontrollable degradation can be an undesirable feature. In this study, we characterized gels formed using a combination of partial oxidation of polymer chains and a bimodal molecular weight distribution of polymer. Specifically, alginates were partially oxidized to a theoretical extent of 1% with sodium periodate, which created acetal ...
Simultaneous measurement of the molecular weight distribution and 5-ethylidene-2-norbornene content across the molecular weight distribution of ethylenepropylenediene terpolymer via a new size exclusion chromatographyultravioletrefractive index method Journal of Applied Polymer Science , 2016, 133 , 43911 Z. Zhou, M. Janco, R. Cong, D. Lee, C. Li...
We have used Soxhlet solvent purification to fractionate a broad molecular weight distribution of the polycarbazole polymer PCDTBT into three lower polydispersity molecular weight fractions. Organic photovoltaic devices were made using a blend of the fullerene acceptor PC71BM with the molecular weight fractions. An average power conversion efficiency of 5.89% (peak efficiency of 6.15%) was measured for PCDTBT blend devices with a number average molecular weight of Mn = 25.5 kDa. There was significant variation between the molecular weight fractions with low (Mn = 15.0 kDa) and high (Mn = 34.9 kDa) fractions producing devices with average efficiencies of 5.02% and 3.70% respectively. Neutron reflectivity measurements on these polymer:PC71BM blend layers showed that larger molecular weights leads to an increase in the polymer enrichment layer thickness at the anode interface, this improves efficiency up to a limiting point where the polymer solubility causes a reduction of the PCDTBT concentration ...
Circulating immune complexes (CIC) were isolated from 25 patients with rheumatoid arthritis (RA) by anti-C1q affinity chromatography. The components were detected by silver stained sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) gels and identified by the Western blot. The CIC were composed of 20 different polypeptides, including albumin, immunoglobulin, complement, and acute phase reactants. Two components (molecular weight 48 kD and 45 kD respectively) remained unidentified. The 48 kD polypeptide was found in CIC from six out of 14 patients (43%) with extra-articular RA, but from none of eight patients with vasculitic complications of other connective tissue diseases. All immunoreactants were more frequently found in the patients with extra-articular features of RA. Although these results emphasise that most CIC in RA are composed of endogenous proteins, the 48 kD polypeptide is a candidate for an extrinsic antigen in RA. ...
The key aims of polystyrene production methods are high molecular weight, narrow molecular weight distribution, good productivity, and high conversion rates of the styrene monomer to polymer. The molecular weight distribution of styrene polymerization is one of the most important factors as this property affects the end products impact and tensile strength, brittleness, hardness, and softening temperature. Optimizing the molecular weight distribution - and maintaining it in scale-up - is particularly important to ensure reproducible polystyrene production at large scales.. Polystyrene production methods have remained largely unchanged since they were first used commercially in 1931. Traditionally, batch emulsion, solution, or suspension polymerization methods have been the preferred choice for polystyrene manufacture. These methods offer limited control in molecular weight, molecular weight distribution, and the conversion of monomer to polymer but have the benefit of enabling easy scale-up. ...
HIGHLIGHTS Integrin Antagonists and Other Low Molecular Weight Compounds as Inhibitors of Angiogenesis: New Drugs in Cancer Therapy** Athanassios Giannis* and Frank Riibsam Angiogenesis (neovascularization), the process by which new blood capillaries are formed from an already existing blood vessel, is of fundamental importance for a number of physiological and pathological events including embryogenesis, wound healing, chronic inflammation. and malignant processes.[] Due to the observation that an adequate blood supply is necessary for tumor growth, Folkman postulated in the early 1970s that inhibitors of angiogenesis are of potential use in cancer therapy.[] Subsequent investigations revealed that not only tumor growth but also tumor metastasis depends on angiogenesi~.[~] In recent years many endogenous regulators of angiogenesis have been isolated and identified. The most important positive regulators include growth factors like basic fibroblast growth factor (bFGF), vascular endothelial ...
In this work, three isotactic linear polypropylenes, with weight average molecular weights between 56 250 - 75 850 g/mol, have been characterized at 230 oC over a very wide shear rate range. A low shear rate primary Newtonian plateau, a pseudoplastic region and a well developed secondary Newtonian plateau were identified for all the polypropylene melts. Flow activation energy at low (E0) and high (E∞) shear rates was found to be 56.590 kJ/mol and 25.204 kJ/mol, respectively. For the first time, it has been discovered that the secondary Newtonian viscosity, η∞, depends linearly on the weight average molecular weight, Mw, in log-log scale as η∞ = 1.19. 10-6 M 1.084 . The observed slope close to 1 w between η∞ and Mw suggests that polymer chains in the melt are disentangled at the secondary Newtonian plateau region. This conclusion is supported by the experimental observation that the high shear rate flow activation energy E∞ for given PP melts is comparable with the flow activation ...
article{9ffe9df9-5a4c-440c-bdd1-534be5ba851a, abstract = {We report a case of a 5-year-old child who suffered an oral allergy syndrome and lip angiedema after eating grapes. We obtained a positive prick test with commercial grape extract and a positive prick-by-prick test with pulp and peel of fresh white grape (Moscatel variety) and pulp and peel of blue grape. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis followed by immunoblotting revealed specific immunoglobulin E (IgE) antibodies in the patients serum against a 94,000 molecular-weight antigenic band. Lip open challenge was positive.}, author = {Rodriguez, Angel and Trujillo, María Jesús and Matheu, Victor and Baeza, María Luisa and Zapatero, Lidia and Martinez, Maribel}, issn = {0905-6157}, language = {eng}, number = {5}, pages = {289--290}, publisher = {Wiley-Blackwell}, series = {Pediatric Allergy and Immunology}, title = {Allergy to grape: a case report}, url = {http://dx.doi.org/10.1034/j.1399-3038.2001.00064.x}, volume ...
Background: Prawns and shrimp certainly are a regular cause of sea food allergy mediated by IgE antibodies. adjustments. Quickly the shell and meats of each varieties had been combined in 1 M phosphate-buffered saline (pH 7.2) and extracted overnight in 4 °C under regular blending. The homogenates had been centrifuged at 14 000 rpm at 4 °C for a quarter-hour. The supernatants had been sterile-filtered lyophilised and kept at after that ?20 °C until make use of. For preparation of the boiled extracts the homogenates of the prawns were boiled for 5 minutes before extraction as described above. The protein concentration of each extract was decided using the Total Protein Kit (Sigma-Aldrich UK) and bovine serum albumin as a standard. SDS-PAGE of prawn extracts Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) was performed as described by Nakano et al. (17) with some modifications. The samples of the extracts were heated at 97 °C for 4 minutes and Precision Plus Protein ...
Filaments with a diameter of 80-120 Å have been prepared from 14-d-old chick embryonic skeletal muscle, using a physiological salt solution and gel filtration chromatography. The filaments obtained are composed of the two known muscle intermediate-filament proteins, vimentin and desmin, as well as the vimentin- and desmin-associated high molecular weight protein, synemin (230,000 mol. wt). In addition, they contain a previously unidentified high molecular weight protein (280,000 mol wt) which differs from synemin by isoelectric point, molecular weight, and immunological reactivity. Immunofluorescence on cultured myogenic cells,using antisera to the 280,000-dalton polypeptide, has revealed that this protein has the same spatial distribution as desmin, vimentin, and synemin in both early myotubes, where it associates with cytoplasmic filaments, and late in myotubes, where it is associated with myofibril Z lines. Examination by immunofluorescence of frozen sections of developing embryonic skeletal ...
Pantothenase (EC 3.5.1.22) from Pseudomonas fluorescens UK-1 was purified to homogeneity as judged by disc-gel electrophoresis and isoelectric focusing. The purification procedure consisted of four steps: DEAE-Sephadex chromatography, (NH4)2SO4 precipitation, hydroxyapatite chromatography and preparative polyacrylamide-gel electrophoresis. Gel filtration on Ultrogel AcA 34 was used to determine the molecular weight, and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis to study the subunit molecular weight. The enzyme appeared to be composed of two subunits with mol.wts. of approx. 50000 each. The total mol.wt. of the enzyme was thus about 100000. The isoelectric point was 4.7 at 10 degrees C. ...
The molecular weight is very commonly used as a synonym of molar mass, particularly for molecular compounds; however, the most authoritative sources define it differently (see molecular mass). The formula weight is a synonym of molar mass that is frequently used for non-molecular compounds, such as ionic salts. The molar mass is an intensive property of the substance, that does not depend on the size of the sample. In the International System of Units (SI), the base unit of molar mass is kg/mol. However, for historical reasons, molar masses are almost always expressed in g/mol. The mole was defined in such as way that the molar mass of a compound, in g/mol, is numerically equal (for all practical purposes) to the average mass of one molecule, in daltons. Thus, for example, the average mass of a molecule of water is about 18.0153 daltons, and the molar mass of water is about 18.0153 g/mol. For chemical elements without isolated molecules, such as carbon and metals, the molar mass is computed ...
High Molecular Weight DNA Markers from Invitrogen,High Molecular Weight DNA Markers are suitable for sizing linear double-stranded DNA from 9 to 48 kb on low-percentage agarose gels. The 13 bands consist of 8.3- to 48.5-kb fragments generated from restriction endonuclease digests of Lambda DNA (cIind1ts857 Sam7). Ethidium bromide staining causes t,biological,biology supply,biology supplies,biology product
The effect of low molecular weight water-insoluble hydrocarbon additives on the formation of colloidal particles in suspension polymerization of methyl methacrylate and vinyl acetate has been...
0136] Presently preferred propylene homopolymers and copolymers useful certain exemplary embodiments of this disclosure typically have: 1) a weight average molecular weight (Mw) of at least 30,000 Da, preferably at least 50,000 Da, more preferably at least 90,000 Da, as measured by gel permeation chromatography (GPC), and/or no more than 2,000,000 Da, preferably no more than 1,000,000 Da, more preferably no more than 500,000 Da, as measured by gel permeation chromatography (GPC); and/or 2) a polydispersity (defined as Mw/Mn, wherein Mn is the number average molecular weight determined by GPC) of 1, preferably 1.6, and more preferably 1.8, and/or no more than 40, preferably no more than 20, more preferably no more than 10, and even more preferably no more than 3; and/or 3) a melting temperature Tm (second melt) of at least 30° C., preferably at least 50° C., and more preferably at least 60° C. as measured by using differential scanning calorimetry (DSC), and/or no more than 200° C., ...
Biomarkers are often masked by high abundant proteins or may be susceptible to proteolysis. This application note from Shimadzu Scientific Instruments illustrates the ability to enrich low abundant, low molecular weight proteins directly from serum while excluding high molecular weight proteins. The ability to differentially trap proteins based on bait chemistry is also examined.
PubMed Central Canada (PMC Canada) provides free access to a stable and permanent online digital archive of full-text, peer-reviewed health and life sciences research publications. It builds on PubMed Central (PMC), the U.S. National Institutes of Health (NIH) free digital archive of biomedical and life sciences journal literature and is a member of the broader PMC International (PMCI) network of e-repositories.
PubMed Central Canada (PMC Canada) provides free access to a stable and permanent online digital archive of full-text, peer-reviewed health and life sciences research publications. It builds on PubMed Central (PMC), the U.S. National Institutes of Health (NIH) free digital archive of biomedical and life sciences journal literature and is a member of the broader PMC International (PMCI) network of e-repositories.
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0002]The present invention relates to catalysts component for the polymerization of ethylene and its mixtures with olefins CH2═CHR, wherein R is an alkyl, cycloalkyl or aryl radical having 1-12 carbon atoms, comprising Ti, Mg, halogen, and a particular electron donor compound. The catalyst of the invention is suitably used in (co)polymerization processes of ethylene to prepare (co)polymers having narrow Molecular Weight Distribution (MWD) and high bulk density. The MWD is an important characteristic of ethylene polymers in that it affects both the rheological behavior, and therefore the processability, and the final mechanical properties. In particular, polymers with narrow MWD are suitable for films and injection molding in that deformation and shrinkage problems in the manufactured article are minimized. The width of the molecular weight distribution for the ethylene polymers is generally expressed as melt flow ratio F/E, which is the ratio between the melt index measured by a load of 21.6 ...
Domestic protein purification instrument company on the characteristics of molecular sieve chromatography protein purification system-Suzhou Sepure Instruments Inc.-Domestic protein purification instrument company on the characteristics of molecular sieve chromatography protein purification system
Number Average Molecular Weights (Fundamentals and Determination) by Bonnar Robert U. (ISBN: 978-1-258-79647-1); Published by Literary Licensing, LLCin Aug 2013. Compare book prices on Bookwire.com to buy books from the lowest price among top online book retailers
Site-directed mutagenesis of a synthetic gene coding for low-M(r) phosphotyrosine protein phosphatase from bovine liver has been carried out. The two histidine residues in the enzyme have been mutated to glutamine; both single and double mutants were produced. The mutated and non-mutated sequences have been expressed in Escherichia coli as fusion proteins, in which the low-M(r) phosphotyrosine protein phosphatase was linked to the C-terminal end of the maltose-binding protein. The fusion enzymes were easily purified by single-step affinity chromatography. The mutants were studied for their kinetic properties. Both single mutants showed decreased kcat. values (30 and 7% residual activities for His66 and His72 respectively), and alterations of the Ki values relative to four-competitive inhibitors were observed. The kinetic mechanism of p-nitrophenyl phosphate hydrolysis in the presence of both single mutants was determined and compared with that of the non-mutated enzyme. The rate-determining step ...
It will calculate the total mass along with the elemental composition and mass of each element in the compound. To calculate the molar mass of a compound with multiple atoms, sum all the atomic mass of the constituent atoms. Mass percentage of the elements in the composition To prepare 1 L of 0.5 M sodium chloride solution, then, as per the formula, use 29.22 g of sodium chloride (0.5 mol/L * 1L * 58.44 g/mol = 29.22 g). Table salt (sodium chloride) (NaCl - Molecular mass), molar mass. Examples: Fe, Au, Co, Br, C, O, N, F. You can use parenthesis or brackets []. 0.1M NaCl = Moles/.025L. The molar mass of any molecule is how much mass (in grams) the molecule has per mole. Molarity = Moles/Liters. Molar concentration, also known as molarity, and can be denoted by the unit M, molar. Molar mass of NaCl, Sodium Chloride is 58.44277 g/mol. In chemistry, the formula weight is a quantity computed by multiplying the atomic weight (in atomic mass units) of each element in a chemical formula by the number ...
The purification of glutamate dehydrogenase from sheep rumen mucosa on DEAE-cellulose afforded two enzyme fractions with glutamate dehydrogenase activity. The enzyme fraction II (tissue glutamate dehydrogenase) was freed of contaminating proteins in the subsequent purification step on Sephadex G-200. The approximate relative molecular weight (260 000) of tissue glutamate dehydrogenase (fraction II) was determined by gel filtration on Sephadex G-200 and the approximate relative molecular weight of its polypeptide chain (48 000) was established by polyacrylamide gel electrophoresis in SDS. The pH-optimum of fraction II was 7.9. The effect of substrate concentration on the rate of the enzymatic reaction was examined and the following apparent Michaelis constants were found for the individual substrates: NADH 6.25 . 10-5 mol/l, 2-oxoglutarate 4.5 . 10-3 mol/l, and NH4+ 77 . 10-3 mol/l.. ...
Polysaccharides from sunflower stalk pith (SSP) were extracted by hot water and sodium hexametaphosphate (SHMP). The chemical analyses suggested both fractions dominated in galacturonic acids with small amount of neutral sugars, indicating their identity as pectins. The yield of water-extractable pectin (WEP) and SHMP-extractable pectin (SEP) were 1.8% and 11.0%, respectively. The detailed structure of each fraction was investigated by high performance size exclusion chromatography (HPSEC), FT-IR spectroscopy, methylation analysis and 1D & 2D NMR spectroscopy. The weight average molecular weight and intrinsic viscosity for WEP and SEP were 57.2 kDa, 0.48 dL/g and 23.1 kDa, 0.50 dL/g, respectively. FT-IR spectra confirmed WEP and SEP had characteristic pectin-like structures and the degree of esterification (DE) was calculated to be 92% and 64 %, respectively. Methylation analysis demonstrated that 1,4-GalpA residues dominated all the sugar linkages, while other linkage types including 1,2-Rhap, ...
Chitosan Protasan UP G 210 (FA=0.17, weight-average molecular weight of 162,000) was obtained from Pronova Biomedical AS, Oslo, Norway. The low-molecular weight oligomer of N-glucosamine was obtained by chemical depolymerisation of chitosan using NaNO2 and subsequent reduction by NaBH as described by Tcmmeraas et al.t 2001, where the molecular weight was controlled by the amount of NaNO2 relative to the amount of chitosan. The fraction of acetylated units was controlled by heterogeneous deacetylation to obtain FA of less than 0.001 as determined by proton NMR-spectroscopy as described previously (Varum et al, 1991). Typically, 1.0 gram of chitosan was dissolved in 100 ml of 2.5% aqueous acetic acid, dissolved oxygen was removed by bubbling nitrogen gas through the solution for 5 minutes, and 5 ml of a freshly prepared solution of NaNO2 in distilled water (10 mg/ml) was added. The reaction was allowed to proceed for 4 hours in darkness, whereafter the depolymerized chitosan was conventionally ...
BioAssay record AID 743310 submitted by Burnham Center for Chemical Genomics: SAR confirmation of uHTS small molecule inhibitors of Low Molecular Weight Protein Tyrosine Phosphatase, LMPTP, in a fluorescence-based, VHR-1 (dual specificity phosphatase 3) selectivity assay.
A coating composition useful for a finish for automobiles and trucks in which the film forming binder contains reactive binder components of about (a) 25-94% by weight, based on the weight of the binder, of an acrylic polymer having at least two reactive anhydride groups composed of polymerized monomers of an ethylenically unsaturated anhydride and polymerized monomers from the group consisting of alkyl methacrylate, alkyl acrylate and any mixtures thereof, wherein the alkyl groups have 1-8 carbon atoms and the polymer has a weight average molecular weight of about 2,000-50,000; (b) 5-50% by weight, based on the weight of the binder, of a glycidyl component having at least two reactive glycidyl groups; (c) 1-40% by weight, based on the weight of the binder, of a self-stabilized dispersed resin; and the composition contains about 0.1-5% by weight; based on the weight of the binder, of a catalyst.
Both SDS-PAGE (sodium dodecyl sulphate polyacrylamide gel electrophoresis) and Western blotting are vital and very common methodology for protein extraction and ...
An improved purification procedure for the isolation of ribonuclease H(hybrid nuclease; RNA-DNA-hybrid ribonucleotidohydrolase, EC 3.1.4.34) from the thymus of 4-to 6-months-old calves yields two highly active forms of the enzyme, designated as ribonuclease H1 and H2. Their isoelectric points are 5.0 +/- 0.05 and 5.25 +/- 0.05, respectively; their molecular weight, estimated from gel filtration, is in both cases 64,000 +/- 2000. On sodium dodecyl sulfate gel electrophoresis, two principal bands were identified, with molecular weights of 32,000 and 21,000. The nature of the nucleotides at the 3-OH terminals, produced initially by the enzymic hydrolysis of hybridized RNA, was examined and shown to be a function of the divalent metal ion employed as activator. ...
SUMMARY: The passive permeability properties of the plasma-membrane of Staphylococcus aureus (strain Duncan) resemble those of a classical lipid membrane such as that considered by Overton in 1899. In general, solutes carrying more than four water molecules flow across the plasma-membrane only very slowly under an electrochemical gradient. The plasma-membrane is the effective osmotic barrier to small molecular weight solutes and prevents the escape of internal components having a total osmotic concentration corresponding to c. 1 molal sucrose. The protoplast is prevented from swelling by the cell wall which withstands a hydrostatic thrust of some 20 to 30 atmospheres pressure exerted against it by the plasma-membrane in distilled water. The pores in the cell wall, although large enough to permit rapid diffusion of small molecular weight solutes, are too small to allow a dextran of mol. wt. 10,000 to penetrate. The cell wall acts as the osmotic barrier for large molecular weight components, preventing
Atomic mass is measured via mass spectrometry. Molar mass is computed from the atomic weight. There are no units of measurement for atomic masses because these are relative masses meaning these are unitless. So the atomic mass is measured by calculating the mass of protons and neutrons. Whereas the Molar Mass is the grams per moles of a specific element. (or a specific compound by adding the molar mass of each element in the compound). The molar mass had units (g/moles) and the atomic mass is unitless ...
Poly(ethylene succinate) (PES) with weight-average molecular weight above 60,000 g mol-1 was efficiently obtained by enzymatic ring opening polymerization of cyclic oligo(ethylene succinate)s c(ES)n, which in turn were prepared by lipase-catalysed cyclocondensation in solution of dimethyl succinate and ethylene glycol. The methodology was demonstrated to be also applicable to the synthesis of high molecular weight PES-copolyesters containing butylene succinate, e-hydroxycaproate or L-lactate units with a random distribution ...
Pneumococcus DNA, of weight-average molecular weight 1.6 million by light scattering, had a weight-average length of 4300 A by electron microscopy. Thus, the average mass per unit length was 370 molecular-weight units per A, or approximately two times that expected (208) for a Watson-Crick double helix. This corresponds to an average of 3.6 strands per molecule, which is close to that obtained by other methods. Morphologically, all the particles in the micrographs were relatively stiff, and had a cross-sectional height of 20 to 30 A. Some divided into two stiff branches of the same height, apparently double helical. Where the branches combined into one (minimally four-stranded) structure they apparently lay side by side in close association.. ...
The catalytic (M2) and regulatory (M1) subunits of calf thymus ribnucleotide reductase have been purified to homogeneity. Each runs as a single band in SDS-polyacrylamide gel electrophoresis with polypeptide molecular weights of 84,000 for M1 and 58,000 for M2. Additional evidence for homogeneity was obtained using high performance liquid gel chromatography. The native M1 subunit is predominately monomeric (R(,s) = 37 A) under experimental conditions while the M2 subunit is oligomeric (R(,s) = 53 A). The quaternary structure of the native M2 protein was evaluated by chemical cross-linking with dimethyl suberimidate. The results demonstrate that native M2 protein exists in a dimer-tetramer equilibrium. The amino acid composition of the complementary subunits of the ribonucleotide reductase has been determined. Significant compositional homology exists between the M1 polypeptide and its E. coli (B1) counterpart. However, comparative analytical peptide mapping reveals that the M1 and B1 polypeptides have
A controlled release composition containing a physiologically active substance in high content, suppressing the initial excess release, and achieving a stable release speed over a long period of time is provided. A controlled release composition comprising (1) a physiologically active substance or salt thereof in an amount of about 14% (w/w) to about 24% (w/w) based on the total composition weight, (2) hydroxynaphthoic acid selected from the group consisting of 3-hydroxy-2-naphthoic acid and 1-hydroxy-2-naphthoic acid or salt thereof, and (3) a lactic acid polymer or salt thereof having a weight-average molecular weight of 15000 to 50000 in which the content of polymers having molecular weights of 5000 or less is about 5% by weight or less, wherein the molar ratio of said hydroxynaphthoic acid or salt thereof to said physiologically active substance or salt thereof is from 3:4 to 4:3.
The present work shows the characterization of Phaseolus acutifolius variety latifolius, on which little research has been published, and provides detailed information on the corresponding lectin. This protein was purified from a semi-domesticated line of white tepary beans from Sonora, Mexico, by precipitation of the aqueous extract with ammonium sulfate, followed by affinity chromatography on an immobilized fetuin matrix. MALDI TOF analysis of Phaseolus acutifolius agglutinin (PAA) showed that this lectin is composed of monomers with molecular weights ranging between 28 and 31 kDa. At high salt concentrations, PAA forms a dimer of 63 kDa, but at low salt concentrations, the subunits form a tetramer. Analysis of PAA on 2D-PAGE showed that there are mainly three types of subunits with isoelectric points of 4.2, 4.4, and 4.5. The partial sequence obtained by LC/MS/MS of tryptic fragments from the PAA subunits showed 90-100% identity with subunits from genus Phaseolus lectins in previous reports. The
A new model based on a combination of the polymeric multigrain and multilayer models has been developed to predict the polymerization rate, particle growth, morphology, effective parameters on broadening of the molecular weight distribution, number and weight average of the molecular weight, isotacticity index and bulk density of polymer. Mathematical correlations and the kinetics used in this model are based on the polymeric multigrain and the multilayer models, respectively. In the modeling, multiplicity of active site using different kinetics parameters as well as deactivation of catalyst during the polymerization have been considered,. Moreover, it considers mass transfer effects on polymerization characteristics. The Effects of physico-chemical aspects of catalyst associated with the polymerization in slurry phase are also considered in this model. In addition, the effects of more important model parameters including time step, number of layers and number of active sites on the produced polymer
TY - JOUR. T1 - An electrophoretic difference between surface and secreted IgM of murine splenocytes. AU - Melcher, U.. AU - Uhr, J. W.. PY - 1973. Y1 - 1973. N2 - μ chains on the surface of murine splenocytes are more heterogeneous on SDS polyacrylamide gel electrophoresis than both secreted and intracellular μ chains labeled with [3H]tyrosine. No difference in heterogeneity among cell surface, secreted, or intracellular L chains was detected. The possible role of carbohydrate in μ chain heterogeneity is discussed.. AB - μ chains on the surface of murine splenocytes are more heterogeneous on SDS polyacrylamide gel electrophoresis than both secreted and intracellular μ chains labeled with [3H]tyrosine. No difference in heterogeneity among cell surface, secreted, or intracellular L chains was detected. The possible role of carbohydrate in μ chain heterogeneity is discussed.. UR - http://www.scopus.com/inward/record.url?scp=0015816392&partnerID=8YFLogxK. UR - ...
An aliphatic polyester polymer compositions and preparation method thereof. The invention provides a bioresorbable aliphatic polyester copolymer, comprising the reaction product of a first polyester, a second polyester, and a coupling agent. Specifically, the first polyester and second polyester have the same repeat units, but different weight average molecular weights. Methods for preparing the aliphatic polyester copolymer are provided, in which the first polyester reacts with the second polyester in the presence of the coupling agent, undergoing copolymerization.
Formula:Fe(c2h3o2)3 Enter a chemical formula to calculate molar mass,The molar mass calculator can be used in Chemical industry and medicine industry.
Formula:FeOOH.H2O Enter a chemical formula to calculate molar mass,The molar mass calculator can be used in Chemical industry and medicine industry.
Analysis of zymograms with SDS-polyacrilamide gel electrophoresis containing gelatin as substrate, and performed on samples of haemolymph or fat body taken from Rhodnius prolixus inoculated or not with Enterobacter cloacae, demonstrated distinct patterns of protease activities: (i) in the haemolymph two proteases were induced in insects inoculated with bacteria; (ii) two proteases were detected in the fat bodies derived from non-inoculated controls or insect inoculated with sterile culture medium; (iii) haemolymph and fat body had both the same apparent molecular weights proteases (46 and 56 kDa); and (iv) these enzymes were characterized as metallo-proteases. The association of these enzymes in Rhodnius infected with bacteria was discussed. ...
Polyolefins having a molecular weight distribution Mw /Mn of ≧3 and which may be monomodal, bimodal or multimodal are obtained by polymerization or copolymerization of olefins of the formula RCH═CHR, in which a catalyst system comprising an aluminoxane and a transition-metal component (metallocene) is used, the transition-metal component comprising at least one zirconocene of the formula I ##STR1## and at least one zirconocene of the formula Ia or alternatively at least 2 zirconocenes of the formula I.
The wine that won the International Gold is called Ferguson Estate 2011, a blend of 57% Cabernet, 32% Merlot, and 11% Cab Franc. It was racked five times over its 22 months aging and is, having come from a vineyard planted only six years ago, astoundingly integrated, refined, subtle, and richly reflective of both its terroir and the glorious, brooding Walla Walla Valley fruit. The Ferguson Vineyard, named for Martys wifes parents, Jean and Baker Ferguson, is the sole property of LEcole and is an 18 acre plot situated on a high-elevation hillside just outside Milton-Freewater, Oregon. The purity and clarity of Ferguson is uncanny; most wineries dont produce juice like this even from 60 - 80 year old vines. The flavors are bell-clear, resonant blackberries, black plums, and Bing cherries, graced with mocha, graphite, glove leather, sweet herbs, and fresh figs - all underpinned by a breath-taking, distinct stratum of crushed stones, lime, and mineral soils. Its every bit as remarkable as you ...