• The profile of N protein detection in blood and antibody response to severe acute respiratory syndrome-associated coronavirus (SARS-CoV) from onset of symptoms to the convalescent phase. (cdc.gov)
  • We show that antibodies against proteins belonging to the antigen 85 complex were the most abundant in the serum of M. tuberculosis infected patients, and that secreted lipoproteins were the most immunogenic proteins in term of high antibody to protein amount ratio were lipoprotein, illustrating the importance of this group of proteins for serodiagnostic development. (uib.no)
  • Furthermore, EV protein-based analysis was performed by assessing the distribution of 37 EV surface proteins, via flow cytometry fluorescent bead/antibody multiplex assays. (izon.com)
  • enQuire Bio's product, CD68 (Macrophage Marker) MonoSpecific Antibody, is available for Research Use Only (RUO-Only). (enquirebio.com)
  • Unattached fluorescent antibody and other proteins are removed by centrifugation. (cdc.gov)
  • Using an anti-human RBP antibody (Ab), this study first demonstrates feline urinary RBP by Western blot analysis and then evaluates its potential as a renal marker in cats by enzyme-linked immunosorbent assay (ELISA). (avmi.net)
  • Human papillomavirus (HPV) proteins may elicit antibody responses in the process towards HPV-related malignancy. (who.int)
  • Tumor marker tests look for substances, called tumor markers, that are often made by cancer cells or normal cells in response to cancer . (medlineplus.gov)
  • We have developed an antigen-capture enzyme-linked immunosorbent assay (ELISA) based on monoclonal antibodies against the nucleocapsid (N) protein of SARS-CoV ( 7 ), a predominant antigen produced in the infected cell-culture filtrate. (cdc.gov)
  • We attempt to demonstrate the temporal profile of the N protein and antibodies in serum samples from a large cohort of patients with SARS during the acute and convalescent phases of the disease. (cdc.gov)
  • Briefly, 100 μL of serum was added to the wells of a microtiter plate coated with a mixture of three anti-N protein monoclonal antibodies, and the plates were incubated at 37°C for 60 min. (cdc.gov)
  • Abcam: antibodies, proteins, kits. (abcam.cn)
  • ECSA Scientific Day 2023 (23 November 2023): Antibodies against high-risk human papillomavirus proteins as markers for noncervical HPV-related cancers in a black South African population, according to HIV status. (who.int)
  • Antibodies against E6, E7 and L1 proteins of HPV16 and HPV18 were measured in sera of 535 cases of noncervical HPV-related cancers (anal (n=104), vulval (n=211), vaginal (n=49), penile (n=37) and oropharyngeal (n=134)) and 6,651 non-infection-related cancer controls, from the Johannesburg Cancer Study that recruited Black South African with newly diagnosed cancer between 1995 and 2016. (who.int)
  • Within the past 2 years, investigational peptide- and recombinant protein-based serologic assays that can more easily differentiate the antibodies to HTLV-I and HTLV-II have been developed (8,9). (cdc.gov)
  • A blue protein standard with 12 prestained proteins covering a wide range of molecular weights: 10-240kDa in Tris-Glycine buffer and 9-235kDa in Bis-Tris (MOPS) buffer or Bis-Tris (MES) buffer. (gbiosciences.com)
  • Three-color protein standard with 12 pre-stained. (itwreagents.com)
  • The gene and protein expression profiles and protein distribution of six potential genetic biomarkers (i.e. (altmetric.com)
  • Erisyon will use its single-molecule protein sequencing technology to detect and validate biomarkers for early detection of Parkinson's disease. (genomeweb.com)
  • In this study, we showed that the human RFC (hRFC) gene can serve as a novel selectable marker for the overproduction of recombinant proteins. (aspetjournals.org)
  • These results establish a novel RFC-based metabolic selection system for the efficient overexpression of recombinant proteins. (aspetjournals.org)
  • Recombinant full length protein corresponding to Rat PSD95. (abcam.com)
  • Recombinant fragment of human CD68 protein (apprx. (enquirebio.com)
  • This book chapter will comment on fluorescent reporter proteins and nanocrystals' applicability as fluorescent markers. (intechopen.com)
  • Fluorescent reporter proteins in the Drosophila model system offer a degree of specificity that allows monitoring cellular and biochemical phenomena in vivo, such as autophagy, mitophagy, and changes in the redox state of cells. (intechopen.com)
  • Therefore, this chapter will show exciting results of the group using fluorescent proteins and nanocrystals in biological systems. (intechopen.com)
  • Toward this end, a hemagglutinin (HA) epitope tagged hRFC (hRFC-HA) was introduced into a bicistronic vector (pIRES2-EGFP), upstream of an enhanced green fluorescent protein (EGFP) reporter gene. (aspetjournals.org)
  • Subsequently, investigations based on EV miRNAs, mRNAs or surface proteins have flooded the biomarker research space . (izon.com)
  • In the three qEV-derived pools and unprocessed plasma, EV DNA and EV surface proteins were assessed and compared in their biomarker value. (izon.com)
  • Each standard protein is covalently conjugated with a different chromophore, producing a colourful ladder for easy identification of protein size. (topsan.org)
  • Proteins are covalently coupled with a blue chromophore except for two reference bands. (gbiosciences.com)
  • Proteins are covalently coupled with a. (gbiosciences.com)
  • Proteins, the marker consists of, are covalently bonded with the blue dye. (blirt.eu)
  • Proteins are covalently coupled with a blue chromophore except for two reference bands (one green and one red band at 25 kDa and 75 kDa respectively). (itwreagents.com)
  • Opti-Protein Express Marker consists of five proteins that resolve into sharp bands in the range of 16 to 100 kDa. (topsan.org)
  • The technology of the tool is supposedly based on five proteins expressed in melanoma tissue. (healthjockey.com)
  • We examined the acute effects of different dietary protein sources (0.19 g, dissolved in 1 ml of water) on skeletal muscle, adipose tissue and hypothalamic satiety-related markers in fasted, male Wistar rats (~250 g). (biomedcentral.com)
  • Higher amounts of whey versus egg protein stimulate the greatest post-treatment anabolic skeletal muscle response, though test proteins with higher amounts of WPH more favorably affected post-treatment markers related to adipose tissue lipolysis. (biomedcentral.com)
  • Finally, although collagen genes were downregulated the protein immunostaining did not reveal significant changes between the scrapie-infected and control animals. (altmetric.com)
  • HER2 genes have instructions for making the HER2 protein. (medlineplus.gov)
  • HER2 positive , which means the cancer has high levels of the HER2 protein or HER2 genes. (medlineplus.gov)
  • HER2 negative , which means your cancer cells have little to no HER2 protein or a normal number of HER2 genes. (medlineplus.gov)
  • There are different HER2 tumor marker tests for checking HER2 proteins and HER2 genes. (medlineplus.gov)
  • Our results provide novel biological insights in the initiation of liver stage schizogony and an early marker suitable for the development of drug discovery assays predictive of anti-relapse activity. (elifesciences.org)
  • Recently, concern that this marker may not be as reliable as previously thought, coupled with an urgentneed for a pre-clinical live animal test, has led to the search for alternative assays for the detection of TSE disease. (biomedcentral.com)
  • The Yale Cancer Center research team apparently examined the protein expression from a notable set of tumor samples of patients taken from 1959 to 1994. (healthjockey.com)
  • The predictive tool is claimed to be based on the AQUA system, a technology created at Yale School of Medicine by Rimm and Robert L. Camp, M.D. AQUA is believed to mechanically gauge and restrict particular variations in protein expression inside a tissue with an elevated stage of accuracy. (healthjockey.com)
  • The purpose of this study was to identify potential therapeutic strategies to slow down or prevent the expression of early-onset epithelial to mesenchymal transition (EMT) marker proteins (fibronectin and alpha smooth muscle actin, α-SMA) without sacrificing the synthesis and accumulation of the prosurvival protein vascular endothelial growth factor (VEGF) in cultured virally transformed human lens epithelial (HLE) cells. (molvis.org)
  • A hypoxia-inducible factor-1α (HIF-1α) translation inhibitor and an HIF-2α translation inhibitor were independently employed to evaluate the effect of hypoxia inducible factor inhibition on EMT marker protein and VEGF expression. (molvis.org)
  • XAV932 was used to assess the suppression of nuclear β-catenin and its downstream effect on EMT marker proteins and VEGF expression. (molvis.org)
  • In marked contrast, data from the hypoxic condition clearly establish that nuclear β-catenin plays little apparent role in the expression of EMT marker proteins. (molvis.org)
  • Instead, the loss of HIF-1α (but not HIF-2α) decreases the expression of the EMT marker proteins without sacrificing the levels of the prosurvival protein VEGF. (molvis.org)
  • Decrease of GABAergic Markers and Arc Protein Expression in the Frontal Cortex by Intraventricular 192 IgG-Saporin. (atsbio.com)
  • Jeong DU, Chang WS, Hwang YS, Lee D, Chang JW (2011) Decrease of GABAergic Markers and Arc Protein Expression in the Frontal Cortex by Intraventricular 192 IgG-Saporin. (atsbio.com)
  • This "proof of concept" study, examines the use of differential protein expression profiling using surface enhanced laser desorption and ionisationtime of flight mass spectrometry (SELDI-TOF) for the diagnosis of TSE disease. (biomedcentral.com)
  • Differential protein expression between groups is thus highlighted and statistically significant protein "peaks" used to construct a panel of disease specific markers. (biomedcentral.com)
  • We demonstrate that by combining the most statistically significant changes in expression, a panel of markers can be constructed that can distinguish between TSE diseased and normal animals. (biomedcentral.com)
  • Differential protein expression profiling has the potential to be used for the detection of disease in TSE infected animals. (biomedcentral.com)
  • The expression of the CAPN6 protein increased in the spinal cord and cerebellum of the clinical and preclinical brains. (altmetric.com)
  • The distribution of the GALA1 was identified in glial cells from the cerebellum of scrapie-infected animals, GALA1 protein expression was increased in clinical animals in the majority of regions, and the increase of MT2A was in agreement with previous reports. (altmetric.com)
  • In conclusion, this study of gene transcription and protein expression and distribution confirm CAPN6, GALA1, MTNR1B and MT2A as potential targets for further prion disease research. (altmetric.com)
  • an effect which may be explained by an increased expression of adipose tissue lipolysis-related gene expression patterns following chronic supplementation [ 12 ], an increase in protein-induced thermogenesis (reviewed in [ 15 ]), and/or a consistent reduction in food intake given its satiety-stimulatory effects as discussed above. (biomedcentral.com)
  • Here, we examined the expression of the HE4 gene and protein in a large series of normal and malignant adult tissues by oligonucleotide microarray and tissue microarray, respectively. (nature.com)
  • Here, we used oligonucleotide and tissue microarrays to survey HE4 gene and protein expression in a large group of malignant and normal tissues from adults. (nature.com)
  • Conclusion: Expression of ERh is an independent marker for favorable prognosis after adjuvant tamoxifen treatment in ERa-negative breast cancer patients and involves a gene expression program distinct from ERa. (lu.se)
  • This unique protein ladder provides an easy method to monitor protein separation during electrophoresis, estimate the molecular weight of the protein of interest and evaluate western blot transfer efficiency. (topsan.org)
  • G622Opti-Protein Precision Marker is a mixture of 9 orange-, pink- and blue-stained proteins for use as size standards in protein electrophoresis (SDS-PAGE) and. (topsan.org)
  • These broad range protein standards are optimized for SDS-PAGE gel electrophoresis in Western Blotting processes. (gbiosciences.com)
  • and b) liberate bioactive peptides that are able to exhibit physiological responses that otherwise would be diminished from consuming intact protein sources. (biomedcentral.com)
  • Our analysis of this data reveals an absolute protein-to-RNA ratio of 10 2 -10 4 for bacterial populations and 10 3 -10 5 for an archaeon, which is more comparable to Eukaryotic representatives' humans and yeast. (nature.com)
  • Therefore, RBP has been used as a renal marker in humans and dogs. (avmi.net)
  • Mapping of proteins exported by the pathogen to the extracellular environment is necessary to understand the biology of the pathogen and for identification of novel drug targets and vaccine candidates to eliminate the disease. (uib.no)
  • Interestingly, significant increase in PIIINP was associated with HICS treatment and improved MRSS suggesting that this may be a marker of extracellular matrix turnover. (quanterix.com)
  • In work supported by the Michael J. Fox Foundation, the researchers identified protein markers for the condition in extracellular vesicles collected from urine. (genomeweb.com)
  • We aimed to assess the value of liver fatty acid binding protein (L-FABP) in the diagnosis of non-alcoholic fatty liver disease in comparison to ultrasonography. (scirp.org)
  • Current tests for the diagnosis of these diseases are based on the detection of an abnormal misfolded form of the host protein PrP which is found within the central nervous and lymphoreticular systems of affected animals. (biomedcentral.com)
  • Definitive diagnosis has historically therefore, been restricted to post -mortem examination of brain tissue for the presence of pathological hallmarks of the disease such as spongiform changes and the deposition of an abnormal disease related form of the prion protein termed PrP d ( d denotes a disease associated form of the host encoded protein PrP c ) [ 5 ]. (biomedcentral.com)
  • Cardiac markers are used in the diagnosis and risk stratification of patients with chest pain and suspected acute coronary syndrome (ACS). (medscape.com)
  • Note that cardiac markers are not necessary for the diagnosis of patients who present with ischemic chest pain and diagnostic ECGs with ST-segment elevation. (medscape.com)
  • The culture filtrate protein mixture of M. tuberculosis used in our first work investigated to identify novel antigens. (uib.no)
  • A total of 20 serological reactive proteins were identified, including 4 novel antigens. (uib.no)
  • The N protein-capture ELISA was performed ( 7 ). (cdc.gov)
  • The results for the 420 serum specimens tested by the N protein-capture ELISA are shown in Figure 1 . (cdc.gov)
  • In conclusion, RBP is demonstrated for the first time in urine from most CRF and HT patients and the validated ELISA allows its evaluation as a putative renal marker in cats. (avmi.net)
  • A model of proteins' molecular weight for Blue Prestained Protein Marker is a mixture of carefully selected 10 stained, proteins within a wide range of masses (10 -180 kDa). (blirt.eu)
  • Cluster analysis, SAM multiplex testing and paired comparison of individual analytes identified proteins that were upregulated or downregulated during treatment with HICS. (quanterix.com)
  • Urinary kidney markers are a diverse set of analytes often used to measure many complex and serious medical conditions including: obesity, renal disease, cardiac disease, hypertension, diabetes and hepatic disease. (cdc.gov)
  • The work is motivated by a real experiment of gels for renal cancer and our approach allows for the possibility of missing and misallocated markers. (projecteuclid.org)
  • Instead of focusing on markers within the tumor cells, the team pivoted to examine the role cells surrounding the tumor might play in the efficacy of radiotherapy. (diagnosticimaging.com)
  • The aim of this study was to examine the role of stemness proteins in breast cancer cell lines and anti-hormonal therapy resistance. (lincoln.ac.uk)
  • N protein detection in 420 serum samples from 317 patients with severe acute respiratory syndrome (SARS). (cdc.gov)
  • The detection rate of N protein decreased to 27% on days 11-20 after onset of symptoms. (cdc.gov)
  • Following an outbreak of BSE in cattle which was subsequently linked to the emergence of a new human form of the disease, vCJD, commercial testing for surveillance purposes has focused on detection of this protein (PrP d ) in brain tissue homogenates. (biomedcentral.com)
  • Conclusion: Stemness" proteins are highly expressed in breast cancer cells resistant to tamoxifen therapy. (lincoln.ac.uk)
  • This makes proMBP a marker comparable in diagnostic efficiency to human chorionic gonadotrophin (hCG), and exceeding that of alpha-fetoprotein (AFP) and unconjugated oestriol (uE3), in the second trimester. (nih.gov)
  • N protein can be used as an early diagnostic maker for SARS. (cdc.gov)
  • Our findings suggest that detecting N protein in serum can be used as an early diagnostic marker for SARS. (cdc.gov)
  • The analysis of DNA markers in isolated small EVs did not provide any useful prognostic or diagnostic information for breast cancer, and DNA markers were more effectively detected in unprocessed plasma. (izon.com)
  • The aim of this study was to explore the potential of Heparin-binding protein (HBP) in cerebrospinal fluid (CSF) as a diagnostic biomarker of VRI. (lu.se)
  • It is a highly expressed, cytoplasmic protein found in mature olfactory sensory receptor neurons of all vertebrates. (wikipedia.org)
  • In this context, the exploration of temporal interplay between populations with different lifestyles (comprising metabolism, motility, sporulation, etc.) becomes of primary importance to interpret the changes in fundamental quantities in a microbial community, such as the protein-to-RNA ratio that ultimately impacts the overarching community phenotype(s). (nature.com)
  • 20,000 Human Proteins ), and application (e.g. (enquirebio.com)
  • Human epididymis protein 4 (HE4) was first identified in the epithelium of the distal epididymis and originally predicted to be a protease inhibitor involved in sperm maturation. (nature.com)
  • For monitoring protein migration and transfer, and approximating protein size in Western Blots. (topsan.org)
  • This gene encodes a member of the protein kinase C (PKC) family of serine/threonine protein kinases. (nih.gov)
  • The HE4 (WFDC2) gene encodes a WAP-type four disulphide core domain-containing protein with a presumptive role in natural immunity. (nature.com)
  • The cardiac troponins, in particular, have become the cardiac markers of choice for patients with ACS. (medscape.com)
  • Up to 80% of patients with acute MI will have an elevated troponin level within 2-3 hours of emergency department (ED) arrival, versus 6-9 hours or more with CK-MB and other cardiac markers. (medscape.com)
  • Treatment should not be delayed to wait for cardiac marker results, especially since the sensitivity is low in the first 6 hours after symptom onset. (medscape.com)
  • ACC/American Heart Association (AHA) guidelines recommend immediate reperfusion therapy for qualifying patients with ST-segment elevation MI (STEMI), without waiting for cardiac marker results. (medscape.com)
  • The troponins are regulatory proteins found in skeletal and cardiac muscle. (medscape.com)
  • Here we report multiplex protein analysis of blood samples from a placebo-controlled phase II clinical trial and explore mechanisms of action and markers of response. (quanterix.com)
  • Serum or plasma samples at baseline, 26 and 52 weeks were analysed using multiplex or individual immunoassays for 41 proteins. (quanterix.com)
  • As a result, over 100 membrane and membrane-associated proteins were identified including around 50% all predicted lipoproteins in the genome. (uib.no)
  • Another important finding was related to an assessment of membrane-exposed EV proteins, where four proteins were significantly enriched in EVs from breast cancer patients compared to healthy donors. (izon.com)
  • Mrs. Berta Kamprad Foundation, John and practice as a marker associated with prognosis and response to Augusta Persson Foundation for Medical Science, and University Hospital of Lund endocrine therapies such as tamoxifen (4). (lu.se)
  • We consider here the situation where two configurations are matched under various constraints, namely, the configurations have a subset of manually located "markers" with high probability of matching each other while a larger subset consists of unlabeled points. (projecteuclid.org)
  • G252Opti-Protein Marker/Ladder consists of 11 proteins that resolve into sharp, tight bands in the range of 10-175 kDa. (topsan.org)
  • G623With enhanced performance for high molecular weight proteins, Opti-Protein Ultra Marker consists of 10 pre-stained proteins that resolve into sharp, tight bands. (topsan.org)
  • G266Opti-Protein XL Marker/Ladder consists of 12 proteins that resolve into sharp, tight bands in the range of 10-245 kDa. (topsan.org)
  • A study by Sokolova et al of 9 genetic markers for detecting urothelial carcinoma showed that polysomy of chromosomes 3, 7, and 17 and deletion of 9p21 were the most sensitive and specific markers, detecting 95% of recurrent urothelial carcinomas. (medscape.com)
  • Women with low levels of PDGFRb, a protein involved in cardiovascular development, have reduced recurrence risk. (diagnosticimaging.com)
  • Women who have lower levels of a fibroblast protein that is integral to the development of the cardiovascular system - PDGFRb - have a better response to radiotherapy treatment for early-stage breast cancer. (diagnosticimaging.com)
  • High levels of circulating N protein can be detected in the serum samples of patients with SARS. (cdc.gov)
  • Treatment with XAV932 significantly reduced the level of nuclear β-catenin, but the levels of neither the EMT marker proteins nor VEGF were changed. (molvis.org)
  • The study aimed to determine whether serum C-reactive protein (CRP) levels can be used to identify when antibiotics can safely be discontinued in cases of suspected neonatal septicaemia. (who.int)
  • While the field of microbiology has adapted to the study of complex microbiomes via modern meta-omics techniques, we have not updated our basic knowledge regarding the quantitative levels of DNA, RNA and protein molecules within a microbial cell, which ultimately control cellular function. (nature.com)
  • Here we report the temporal measurements of absolute RNA and protein levels per gene within a mixed bacterial-archaeal consortium. (nature.com)
  • RNA/protein levels) to highlight phenotypical complementarity. (nature.com)
  • To establish that these cells are potential senolytic/senomorphic targets of zoledronate, we used single cell proteomic analysis (cytometry by time of flight [CyTOF]) and demonstrated that zoledronate significantly reduced the number of pre-osteoclastic (CD115+/CD3e-/Ly6G-/CD45R-) cells and decreased protein levels of p16, p21, and SASP markers in these cells without affecting other immune cell populations. (sens.org)
  • But these medicines won't help cancers that don't have high levels of HER2 proteins. (medlineplus.gov)
  • C-reactive protein, fibrinogen, and procalcitonin levels as early markers of staple line leak after laparoscopic sleeve gastrectomy in morbidly obese patients within an Enhanced Recovery After Surgery (ERAS) program. (bvsalud.org)
  • Protein Biotechnologies, Inc. manufactures biological products and provides contract laboratory services for the life science research community. (biosciregister.com)
  • What is HER2 tumor marker testing? (medlineplus.gov)
  • HER2 is a type of tumor marker. (medlineplus.gov)
  • HER2 is a protein involved in normal cell growth. (medlineplus.gov)
  • Cancers with large amounts of HER2 protein tend to grow quickly and spread to other parts of the body. (medlineplus.gov)
  • Certain medicines, called HER2 targeted therapy, can block or slow HER2 proteins and help control these cancers. (medlineplus.gov)
  • So, HER2 tumor marker testing is necessary to find out if targeted therapy will be helpful. (medlineplus.gov)
  • But certain cancers have extra copies of the HER2 gene, which leads to too much HER2 protein on the cancer cells. (medlineplus.gov)
  • HER2 tumor marker tests are mostly used to find out whether certain cancers are HER2 positive or negative. (medlineplus.gov)
  • This information shows how fast cancer may grow and whether medicine to target HER2 proteins may be helpful. (medlineplus.gov)
  • Why do I need HER2 tumor marker testing? (medlineplus.gov)
  • What happens during a HER2 tumor marker test? (medlineplus.gov)
  • It is well known that the benefits of radiotherapy are individual, so we need to find predictive markers that can be used to avoid unnecessary or ineffective radiotherapy," said Fredrik Wärnberg, professor in the clinical sciences department at Gothenburg University's Sahlgrenska Academy. (diagnosticimaging.com)
  • Our results show many differentially expressed proteins in diseased and control animals, some at early stages of disease. (biomedcentral.com)
  • Our results suggest mechanisms of action for HICS, including upregulation of α-MSH, that has been shown to be anti-fibrotic in preclinical models, and possible markers to be included in future trials targeting skin in diffuse cutaneous systemic sclerosis. (quanterix.com)
  • [ 14 ] B9d1 and B9d2 are essential components of a B9 protein complex and, when this is disrupted, Meckel syndrome results. (medscape.com)
  • Our results do not support the hypothesis that osteocytes direct the rhythmicity of other bone turnover markers (CTX), at least not via a sclerostinmediated mechanism. (cdc.gov)
  • The N protein could be detected as early as day 1 and until day 18. (cdc.gov)
  • 2017). In this dataset, we identified and characterized the Liver-Specific Protein 2 (LISP2) protein as an early molecular marker of liver stage development. (elifesciences.org)
  • Studies at both terminal stages of disease and throughout the time course of disease have shown a disease specific protein profile or "disease fingerprint" which could be used to distinguish between groups of TSE infected and uninfected animals at an early time point of disease. (biomedcentral.com)
  • The presence of low molecular weight retinol binding protein (RBP) in urine reflects tubular damage. (avmi.net)
  • We examined the potential of proMBP as a maternal serum marker for fetal Down syndrome (DS) by determining its maternal serum concentration (MSpMBP) in 25 Down syndrome (DS) pregnancies and 152 control pregnancies in the first trimester, and in 105 DS pregnancies and 156 control pregnancies in the second trimester. (nih.gov)
  • Kanti V. Mardia, Emma M. Petty, Charles C. Taylor "Matching markers and unlabeled configurations in protein gels," The Annals of Applied Statistics, Ann. (projecteuclid.org)