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2.
Two hundred and three patients with single thyroid nodules were referred for radioactive scan of the thyroid. Solitary “cold” nodules were identified in 130 patients and 68 of these patients came to surgery. Of this group, 12 patients were found to have carcinoma. There was no obvious selection process which distinguished the 68 patients who underwent surgery from the 62 who did not. There is a significant risk of thyroid neoplasms occurring in patients with solitary “cold” nodules, and this is particularly true in patients under forty. 相似文献
3.
Gerard N. Burrow Jeffrey Hopkins Yeshi Dhonden Lobsang Dolma 《The Yale journal of biology and medicine》1978,51(4):441-447
The visit of two Tibetan physicians provided a unique opportunity to gain insight into a practice of medicine very different from that of Western civilization. Initial discussions indicated that the practice of medicine and mysticism were inextricably interwoven in the Tibetan culture. Accordingly, the focus of the study was directed to goiter, which is both common in the Himalayas and easy to define.In Tibetan medical practice, illness is considered to be derived from both proximate and distant causes. Three humors, “wind,” “bile,” and “phlegm” are thought to be responsible for normal mental and physical functions when in balance, but disease when out of balance. Goiter was thought to be due to an imbalance of these humors. The Western discovery that endemic goiter in the Himalayas was due to iodine deficiency explained the proximate cause but did not explain why some individuals have goiter and others do not in the same iodine deficient village. 相似文献
4.
J L Meinkoth P K Goldsmith A M Spiegel J R Feramisco G N Burrow 《The Journal of biological chemistry》1992,267(19):13239-13245
Thyrotropin (TSH) is an important regulator of thyroid follicular cells. While its role in the maintenance of differentiated functions is undisputed, its role as a mitogen is less clear. TSH induces DNA synthesis and cell proliferation in some cells, while in others, TSH is mitogenic only in the presence of additional growth factors such as insulin-like growth factor-1. TSH causes elevations in intracellular cAMP and is thought to utilize this second messenger system in its mitogenic action. We studied TSH as a mitogen in Wistar rat thyroid cells (WRT) (Brandi, M. L., Rotella, C. M., Mavilia, C., Franceschelli, F., Tanini, A., and Toccafondi, R. (1987) Mol. Cell. Endocrinol. 54, 91-103) and examined the role of the guanine nucleotide binding protein, Gs, in its mitogenic action. WRT cells synthesized DNA in response to TSH and elevations in cAMP. In addition, TSH caused a rapid stimulation of an indicator gene whose expression is regulated by cAMP response elements. Following microinjection of an inhibitory polyclonal antibody raised against the Gs protein, both TSH-induced changes in gene expression and DNA synthesis were significantly reduced. These results demonstrate that virtually all of the mitogenic action of TSH is transduced through the Gs protein in WRT cells, presumably through the regulation of adenylate cyclase. Whether all or only part of TSH action is mediated by cAMP and the cAMP-dependent protein kinase remains to be determined. 相似文献
5.
Thyrotropin (TSH) stimulated the phosphorylation of histone H1 in calf thyroid slices but had no effect on other classes of histones. Phosphorylation of total phenol-soluble nonhistone chromosomal proteins was not affected by incubation with TSH. However, when these phenol-soluble nonhistone chromosomal proteins were analysed by two-dimensional gels involving isoelectrofocusing and dodecyl sulfate-polyacrylamide gel electrophoresis, TSH was shown to stimulate the phosphorylation of two specific groups of phosphoproteins with molecular weights between 35,000 and 45,000 and isoelectric points at pH values of 5.4-6.0. This increase in phosphorylation with TSH stimulation was confirmed by quantitative analysis of one-dimensional isoelectrofocusing gels. 相似文献
6.
There is a need for in vivo applicable Fe(3+) and Al(3+) chelation compounds for use as medicines to treat toxic overload conditions of these ions. A novel compound, 2-deoxy-2-(N-carbamoylmethyl-[N'-2'-methyl-3'-hydroxypyrid-4'-one])-D-glucopyranose, designed to chelate Fe(3+) or Al(3+), has been synthesised utilising three naturally occurring products: maltol, glycine and glucosamine. The synthesis is a simple two step process. First, glycine is coupled to maltol by an aminolysis reaction, to yield the intermediate product 1-carboxymethyl -3-hdroxy-2-methylpyrid-4-one, which is joined with glucosamine using a dicyclohexylcarbodiimide promoted peptide coupling method to produce the desired end product, 2-deoxy-2-(N-carbamoylmethyl-[N'-2'-methyl-3'-hydroxypyrid-4'-one])-D-glucopyranose. The latter has been given the trivial name Feralex-G. NMR analysis permitted assignment of frequencies for all carbon and covalently bound hydrogen atoms and was consistent with the proposed structure of the compound. Electron spray Ionisation Mass Spectrometry (ESI-MS) yielded the expected molecular mass of 344. Proton displacement/pH titration analysis yielded three Feralex-G molecules bound to 1 Al(3+) or Fe(3+) over a measurable pH range of 3-10.5. A rapid TLC method to monitor progression of the synthetic procedures is also described. 相似文献
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Serial sectioning of a nodule encapsulating an adult specimen of the arthrodire placoderm Watsonosteus fletti from the Eday Flagstone Formation (Givetian) in the Orcadian Basin of northern Scotland has revealed the presence of a number of embryos within the adult. This specimen represents the oldest known record of fossilized vertebrate embryos. Thin sections of two of the slices have revealed the detailed histological structure of embryonic plates in placoderms, showing that as previously deduced from visual examination, the outer and inner layers were the first to form. Gut contents preserved near the embryos show that the species had a varied diet, with dermal bone fragments from sarcopterygians and placoderms. 相似文献
9.
Carole J. Burrow 《Historical Biology》2013,25(1-4):213-228
Several articulated, but incomplete, acanthodians from the Bunga Beds (late Givetian/early Frasnian) of the southern coast of New South Wales are tentatively identified as ischnacanthids. Heads are missing from all three prepared specimens. They exhibit the following characters: two dorsal fin spines; long, slender scapulocoracoids; slender, relatively deeply inserted, unpaired fin spines; minute scales with a fairly smooth, flat, crown; and an increase in size of normal body scales towards the tip of the tail. The fish are preserved in black, finely laminated shales, which were probably deposited as deep water, lacustrine sediments. The rarity, burial conditions, and headless state of the Bunga Beds acanthodians indicate that they might have died in shallow water, sunk to the bottom, refloated by gas‐induced buoyancy, with the heads lost while drifting out to deeper waters, where the bodies finally sank to a scavenger‐free, anaerobic substrate. 相似文献
10.
Gladbachus adentatus is a putative chondrichthyan, known only from the holotype specimen, which comprises an articulated endoskeleton complete from head to pelvic region with the squamation also preserved. The scales superficially resemble those of placoderms more than sharks, in having a similar gross morphology, lamellar cellular bone forming the base and upright dentinous tubercles comprising the crown. The odontocytic mesodentine in the tubercles is comparable to that in the Osteostraci and in some acanthodian taxa, known only from isolated scales, and is probably the plesiomorphic form of dentine for Gnathostomata. 相似文献