Plasmodesmata: Membrane-like channels of cytoplasm connecting adjacent plant cells. Plasmodesmata connect through pores in the CELL WALL and associate with the CYTOSKELETON machinery. They are essential for intercellular transport and communication.Plant Viral Movement Proteins: Viral proteins that facilitate the movement of viruses between plant cells by means of PLASMODESMATA, channels that traverse the plant cell walls.Tobacco: A plant genus of the family SOLANACEAE. Members contain NICOTINE and other biologically active chemicals; its dried leaves are used for SMOKING.Cell Wall: The outermost layer of a cell in most PLANTS; BACTERIA; FUNGI; and ALGAE. The cell wall is usually a rigid structure that lies external to the CELL MEMBRANE, and provides a protective barrier against physical or chemical agents.Dextrans: A group of glucose polymers made by certain bacteria. Dextrans are used therapeutically as plasma volume expanders and anticoagulants. They are also commonly used in biological experimentation and in industry for a wide variety of purposes.Chromatography, Gel: Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.Plant Cells: Basic functional unit of plants.Pectins: High molecular weight polysaccharides present in the cell walls of all plants. Pectins cement cell walls together. They are used as emulsifiers and stabilizers in the food industry. They have been tried for a variety of therapeutic uses including as antidiarrheals, where they are now generally considered ineffective, and in the treatment of hypercholesterolemia.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Plant Proteins: Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.Earth Sciences: Fields of science encompassing studies and research from the disciplines of PHYSICS; CHEMISTRY; BIOLOGICAL SCIENCES; and MATHEMATICS; that are related to the planet EARTH. Subfields include atmospheric chemistry; CLIMATOLOGY; ENVIRONMENTAL SCIENCES; GEOGRAPHY; GEOLOGY; geophysics; METEOROLOGY; OCEANOGRAPHY; PALEONTOLOGY; mineralogy; and seismology.Science: The study of natural phenomena by observation, measurement, and experimentation.Cell Wall: The outermost layer of a cell in most PLANTS; BACTERIA; FUNGI; and ALGAE. The cell wall is usually a rigid structure that lies external to the CELL MEMBRANE, and provides a protective barrier against physical or chemical agents.Physics: The study of those aspects of energy and matter in terms of elementary principles and laws. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Internet: A loose confederation of computer communication networks around the world. The networks that make up the Internet are connected through several backbone networks. The Internet grew out of the US Government ARPAnet project and was designed to facilitate information exchange.Portal Vein: A short thick vein formed by union of the superior mesenteric vein and the splenic vein.Nuclear Physics: The study of the characteristics, behavior, and internal structures of the atomic nucleus and its interactions with other nuclei. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Health Physics: The science concerned with problems of radiation protection relevant to reducing or preventing radiation exposure, and the effects of ionizing radiation on humans and their environment.NewsHypertension, Portal: Abnormal increase of resistance to blood flow within the hepatic PORTAL SYSTEM, frequently seen in LIVER CIRRHOSIS and conditions with obstruction of the PORTAL VEIN.Cell Wall: The outermost layer of a cell in most PLANTS; BACTERIA; FUNGI; and ALGAE. The cell wall is usually a rigid structure that lies external to the CELL MEMBRANE, and provides a protective barrier against physical or chemical agents.Plants, Genetically Modified: PLANTS, or their progeny, whose GENOME has been altered by GENETIC ENGINEERING.Plant Proteins: Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.Plant Leaves: Expanded structures, usually green, of vascular plants, characteristically consisting of a bladelike expansion attached to a stem, and functioning as the principal organ of photosynthesis and transpiration. (American Heritage Dictionary, 2d ed)Culture Media: Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.Plant Roots: The usually underground portions of a plant that serve as support, store food, and through which water and mineral nutrients enter the plant. (From American Heritage Dictionary, 1982; Concise Dictionary of Biology, 1990)Genes, Plant: The functional hereditary units of PLANTS.PeptidoglycanPlant Cells: Basic functional unit of plants.Plant Shoots: New immature growth of a plant including stem, leaves, tips of branches, and SEEDLINGS.Cell Wall: The outermost layer of a cell in most PLANTS; BACTERIA; FUNGI; and ALGAE. The cell wall is usually a rigid structure that lies external to the CELL MEMBRANE, and provides a protective barrier against physical or chemical agents.AxisTeaching Materials: Instructional materials used in teaching.Pharmacology, Clinical: The branch of pharmacology that deals directly with the effectiveness and safety of drugs in humans.Choline Deficiency: A condition produced by a deficiency of CHOLINE in animals. Choline is known as a lipotropic agent because it has been shown to promote the transport of excess fat from the liver under certain conditions in laboratory animals. Combined deficiency of choline (included in the B vitamin complex) and all other methyl group donors causes liver cirrhosis in some animals. Unlike compounds normally considered as vitamins, choline does not serve as a cofactor in enzymatic reactions. (From Saunders Dictionary & Encyclopedia of Laboratory Medicine and Technology, 1984)PeptidoglycanScience: The study of natural phenomena by observation, measurement, and experimentation.Ambroxol: A metabolite of BROMHEXINE that stimulates mucociliary action and clears the air passages in the respiratory tract. It is usually administered as the hydrochloride.Video Games: A form of interactive entertainment in which the player controls electronically generated images that appear on a video display screen. This includes video games played in the home on special machines or home computers, and those played in arcades.Spondylolisthesis: Forward displacement of a superior vertebral body over the vertebral body below.