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101.
Nina L. Golitsina Andrey A. Bobkov Irina V. Dedova Dmitrii A. Pavlov Olga P. Nikolaeva Victor N. Orlov Dmitrii I. Levitsky 《Journal of muscle research and cell motility》1996,17(4):475-485
Summary The effects of various modifications of rabbit skeletal myosin subfragment 1 on thermal denaturation of subfragment 1 in ternary complexes with Mg-ADP and orthovanadate (Vi) or beryllium fluoride (BeFx) have been studied by differential scanning calorimetry. It has been shown that specific modifications of SH1 group of Cys-707 by different sulfhydryl reagents, trinitrophenylation of Lys-83, and reductive methylation of lysine residues promote the decomposition of the S1·ADP·Vi complex and change the character of structural transitions of the subfragment 1 molecule induced by the formation of this complex, but they have much less or no influence on subfragment 1 thermal stability in the S1·ADP·BeFx complex. Thus, the differential scanning calorimetric studies on modified subfragment 1 preparations reveal a significant difference between S1·ADP·Vi and S1·ADP·BeFx complexes. It is suggested that S1·ADP·Vi and S1·ADP·BeFx complexes represent structural analogues of different transition states of the ATPase cycle, namely the intermediate states S1**·ADP·Pi and S1*·ATP, respectively. It is also proposed that during formation of the S1·ADP·Vi complex the region containing both Cys-707 and Lys-83 plays an important role in the spread of conformational changes from the active site of subfragment 1 ATPase throughout the structure of the entire subfragment 1 molecule. In such a case, the effects of reductive methylation of lysine residues on the subfragment 1 structure in the S1·ADP·Vi complex are related to the modification of Lys-83. 相似文献
102.
In order to characterize the localization of the sigma(1) receptor in the adult rat central nervous system, a polyclonal antibody was raised against a 20 amino acid peptide, corresponding to the fragment 143-162 of the cloned sigma(1) receptor protein. Throughout the rostrocaudal regions of the central nervous system extending from the olfactory bulb to the spinal cord, intense to moderate immunostaining was found to be associated with: (i) ependymocytes bordering the entire ventricular system, and (ii) neuron-like structures located within the parenchyma. Double fluorescence studies confirmed that, throughout the parenchyma, sigma(1) receptor-immunostaining was essentially associated with neuronal structures immunostained for the neuronal marker betaIII-tubulin. In all rats examined, high levels of immunostaining were always associated with neurons located within specific regions including the granular layer of the olfactory bulb, various hypothalamic nuclei, the septum, the central gray, motor nuclei of the hindbrain and the dorsal horn of the spinal cord. In contrast, only faint immunostaining was associated with neurons located in the caudate-putamen and the cerebellum. Electron microscope studies indicated that sigma(1) receptor immunostaining was mostly associated with neuronal perikarya and dendrites, where it was localized to the limiting plasma membrane, the membrane of mitochondria and of some cisternae of the endoplasmic reticulum. At the level of synaptic contacts, intense immunostaining was associated with postsynaptic structures including the postsynaptic thickening and some polymorphous vesicles, whereas the presynaptic axons were devoid of immunostaining.These data indicate that the sigma(1) receptor antibody prepared here, represents a promising tool for further investigating the role of sigma(1) receptors. 相似文献
103.
Stability of Th1 and Th2 populations 总被引:19,自引:0,他引:19
Perez Victor L.; Lederer James A.; Lichtman Andrew H.; Abbas Abul K. 《International immunology》1995,7(5):869-875
Using an in vitro model for the development of IFN-y-producIng(Th1) and IL-4-produclng (Th1) cells from CD4 T lymphocytesexpressing a transgenlc TCR, we show that IL-12 and IL-4 arethe most potent stimuli for the differentiation of naive T cellsto effector populations. When combinations of cytokines arepresent during T cell priming, the effect of IL-4 Is dominant.Furthermore, differentiated Th1 cells can be converted intoIL-4 producers by exposure to IL-4, but the Th2 phenotype Isnot reversible. The stability of Th2 populations may limit theability to regulate Th2-domlnant responses In pathologic situations. 相似文献
104.
A. Ploska H. Taquet F. Javoy-Agid P. Gaspar F. Cesselin B. Berger M. Hamon J.C. Legrand Y. Agid 《Neuroscience letters》1982,33(2):191-196
The contents of dopamine (determined radioenzymatically) and methionine-enkephalin (assayed by a radioimmunoassay) were measured in several areas of the human brain. The peptide was principally localized in dopamine-rich structures. In patients with Parkinson's disease, in contrast to the general dopamine deficiency, the reduction in methionine-enkephalin was restricted to the mesencephalon, putamen and lateral pallidum. 相似文献
105.
Initial validation of the SLEEP-50 questionnaire 总被引:1,自引:0,他引:1
Initial psychometric properties of the SLEEP-50 questionnaire, designed to detect sleep disorders as listed in the Diagnostic and Statistical Manual of Mental Disorders (4th ed., Text Revision), were examined. The sample consisted of 377 college students, 246 sleep patients, 32 nightmare sufferers, and 44 healthy volunteers. The internal consistency was high (Cronbach's alpha = .85); test-retest correlations fell between .65 and .89. Principal component analysis with a direct oblimin rotation revealed a factor structure that closely matched the designed structure. Sensitivity and specificity scores were promising for all sleep disorders; the agreement between all clinical diagnoses and SLEEP-50-classifications was substantial (kappa = .77). These initial findings indicate that the SLEEP-50 seems able to detect a variety of sleep disorders. The SLEEP-50 can aid in screening for common sleep disorders in the general population. 相似文献
106.
Pituitary morphologic changes in patients with Erdheim-Chester disease have not been described in detail. We report here the
histologic and immunohistochemical findings in the autopsy obtained pituitary of a 35-yr-old woman with extensively disseminated
Erdheim-Chester disease. The posterior lobe was completely replaced by xanthogranulomatous infiltrates, providing an explanation
for the patient’s diabetes insipidus. The anterior lobe was intact and immunohistochemistry demonstrated expression of GH,
TSH, FSH, LH, and alpha subunit within the normal range. A clinically observed decrease of anterior pituitary function was
interpreted as hypothalamic in origin due to massive destruction of the hypophysial stalk and compression of the hypothalamus.
Prolactin immunoreactive cells were numerous, consistent with the view that prolactin cell hyperplasia resulted from the loss
of hypothalamic dopaminergic inhibition. Massive Crooke’s hyalinization in the ACTH-producing cells was considered unrelated
to Erdheim-Chester disease and was the consequence of treatment with pharmacologic doses of glucocorticoid hormones. It can
be concluded that prolactin cell hyperplasia may be the only finding in the adenohypophysis of patients with disseminated
Erdheim-Chester disease. It appears that in our patient the clinically apparent anterior hypopituitarism was not due to the
lack of storage but rather to insufficient release of adenohypophysial hormones caused by the defect in hypothalamic regulation. 相似文献
107.
Moore VA Varela AS Yabsley MJ Davidson WR Little SE 《Journal of clinical microbiology》2003,41(1):424-427
To determine if white-tailed deer may serve as a reservoir host for Borrelia lonestari, we used a nested PCR for the Borrelia flagellin gene to evaluate blood samples collected from deer from eight southeastern states. Seven of 80 deer (8.7%) from 5 of 17 sites (29.4%) had sequence-confirmed evidence of a B. lonestari flagellin gene by PCR, indicating that deer are infected with B. lonestari or another closely related Borrelia species. Our findings expand the known geographic range of B. lonestari and provide the first evidence of this organism in a vertebrate other than humans. 相似文献
108.
Victor A. Sorokin Vladimir F. Fedorov Victor S. Leontiev Yuri P. Blagoi Vladimir L. Galkin 《Macromolecular chemistry and physics.》1987,188(10):2301-2309
The helix-coil transition in Phage T2 DNA in the presence of 6,4 · 10?3 mol/l Mn2+ is studied using light scattering and UV spectroscopy. The transition range is about 0,5°C. Near the temperature of the end of melting Tf the molecular weight Mw and the radius of gyration Rz of the complex are observed to decrease to about one half. At a temperature 0,1–0,25°C higher than Tf, Mw and Rz pass through a minimum, which implies that aggregation is preceded by unwinding of DNA strands. Thus, rise in temperature rather than Mn2+ -induced aggregation causes DNA + Mn2+ melting. 相似文献
109.
The responsiveness of thymocytes on day 8 after irradiation to mitogens or anti-CD3 monoclonal antibody was evaluated in the presence of interleukin 2 (IL-2), interleukin 4 (IL-4), interleukin 6 (IL-6) or phorbol-myristate-acetate (PMA). After irradiation, the thymocytes were poorly responsive to T cell mitogens (Concanavalin A, phytohemagglutinin) and the defect could not be overcome by exogenous IL-2, IL-4, IL-6 or by PMA. In contrast, the combination of the calcium ionophore (A23187) and PMA stimulated thymocyte proliferation to a normal level. The anti-CD3 antibody associated with PMA activated thymocytes above the control values, but this was not observed when anti-CD3 was associated with either IL-2 or IL-4. These results suggest that in the thymic populations present early after irradiation 1) the weak proliferative response to mitogens could be related to a defect at a thymocyte level associated or not to an accessory cell deficiency, 2) the intracellular mechanisms involved in T cell proliferation were not altered, 3) the T cell antigen-receptor/CD3 complex was functional. 相似文献
110.
Victor S Ravindran P 《Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital》1985,12(1):23-32
The anatomical factors influencing fixation of endocardial pacing leads were studied in 50 hearts. Many variations were found in the anterior, posterior and septal papillary muscles, interpapillary connections, and the moderator band. Those variations conducive to lead fixation are illustrated. Vertical bands of muscle that could influence lead fixation were seen inside the right ventricle. Variations in the conus papillary muscle and right ventricular outflow tract that facilitate lead fixation are also illustrated. In a few hearts, attention is drawn to slender support of the anterior cusp of the tricuspid valve. 相似文献