منابع مشابه
the underlying structure of language proficiency and the proficiency level
هدف از انجام این تخقیق بررسی رابطه احتمالی بین سطح مهارت زبان خارجی (foreign language proficiency) و ساختار مهارت زبان خارجی بود. تعداد 314 زبان آموز مونث و مذکر که عمدتا دانشجویان رشته های زبان انگلیسی در سطوح کارشناسی و کارشناسی ارشد بودند در این تحقیق شرکت کردند. از لحاظ سطح مهارت زبان خارجی شرکت کنندگان بسیار با هم متفاوت بودند، (75 نفر سطح پیشرفته، 113 نفر سطح متوسط، 126 سطح مقدماتی). کلا ...
15 صفحه اولCollagen Fibril Formation
Soluble rat tail tendon collagen with intact nonhelical ends and largely free of aggregates was used to study fibril formation in vitro. The process was initiated by raising the pH and warming a cold solution of collagen. Fibril formation was monitored by turbidity and the product was examined by electron microscopy. Optimal conditions that will form fibrils similar to those observed in vivo ar...
متن کاملCollagen structure: evidence for a helical organization of the collagen fibril.
The collagen fibrils of human or guinea pig dermis when exposed to the denaturing agents, urea or guanidine-HC1, dissociated into smaller, disparate subunits, probably aggregates of microfibrils. The process of dissociation demonstrates that the fibrils are assembled helically. Initially, diagonal clefts appear on the surface of the fibril. These clefts are surface manifestations of a spirally ...
متن کاملCollagen fibril formation.
Collagen is most abundant in animal tissues as very long fibrils with a characteristic axial periodic structure. The fibrils provide the major biomechanical scaffold for cell attachment and anchorage of macromolecules, allowing the shape and form of tissues to be defined and maintained. How the fibrils are formed from their monomeric precursors is the primary concern of this review. Collagen fi...
متن کاملElectron microscopy shows periodic structure in collagen fibril cross sections.
X-ray diffraction was used to monitor the effects of electron microscope fixation, staining, and embedding procedures on the preservation of the three-dimensional crystalline order in collagen fibrils of rat tail tendon. A procedure is described in which the characteristic 3.8-nm lateral spacing is preserved, with increased contrast, in the diffraction pattern of the embedded fiber. This spacin...
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ژورنال
عنوان ژورنال: Bulletin of the Chemical Society of Japan
سال: 1962
ISSN: 0009-2673,1348-0634
DOI: 10.1246/bcsj.35.769