首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   584篇
  免费   28篇
  国内免费   3篇
耳鼻咽喉   3篇
儿科学   62篇
妇产科学   38篇
基础医学   87篇
口腔科学   10篇
临床医学   29篇
内科学   78篇
皮肤病学   16篇
神经病学   62篇
特种医学   12篇
外科学   56篇
综合类   12篇
预防医学   42篇
眼科学   8篇
药学   63篇
中国医学   7篇
肿瘤学   30篇
  2023年   4篇
  2022年   17篇
  2021年   8篇
  2020年   13篇
  2019年   7篇
  2018年   14篇
  2017年   8篇
  2016年   10篇
  2015年   18篇
  2014年   29篇
  2013年   33篇
  2012年   44篇
  2011年   47篇
  2010年   24篇
  2009年   20篇
  2008年   33篇
  2007年   34篇
  2006年   22篇
  2005年   29篇
  2004年   36篇
  2003年   36篇
  2002年   31篇
  2001年   6篇
  2000年   8篇
  1999年   10篇
  1998年   4篇
  1997年   4篇
  1996年   3篇
  1995年   7篇
  1994年   2篇
  1993年   5篇
  1992年   2篇
  1991年   2篇
  1990年   3篇
  1989年   3篇
  1988年   3篇
  1987年   4篇
  1986年   3篇
  1985年   6篇
  1984年   2篇
  1982年   2篇
  1981年   3篇
  1979年   3篇
  1978年   1篇
  1977年   3篇
  1976年   2篇
  1975年   1篇
  1972年   1篇
  1971年   2篇
  1969年   2篇
排序方式: 共有615条查询结果,搜索用时 15 毫秒
71.
A 5?-year-old adopted girl was referred to us in view of short stature. After ruling out systemic illness, she was evaluated for growth hormone deficiency (GHD) by stimulation tests. The peak value was 3.47 ng/ml. She was then started on growth hormone (GH). At the end of 6 months of GH therapy, her height velocity was only 3 cm/year. There was a lack of attachment between the mother and the child. She had history of hyperphagia, stealing, and hoarding food. Psychiatry consultation confirmed that the child had appetite disorder, and hence was diagnosed as hyperphagic short stature (HSS). The girl and her parents are undergoing psychiatric therapy for the same. Psychosocial dwarfism seems to originate from serious disturbances in the mother-child relationship. These children mimic patients with GHD, but have poor response to GH therapy. This case underscores the importance of social environment in the growth of the individual.  相似文献   
72.
Developing an efficacious vaccine is one of the highest priorities in tuberculosis research. A vaccine based on T cell epitopes representing multiple antigens is an ideal approach to generate effective cellular immunity against the disease. In the present study, we have selected four T cell epitopes from four well defined Mycobacterium tuberculosis antigens, Ag85C (Rv2903c), 10-kDa culture filtrate protein (CFP-10) (Rv3874), PPE68 (Rv3873) and INV (Rv1478). The epitope encoding genes were grafted into a Cpn 10 based epitope delivery system. The cpn 10-epitope chimeras were further cloned and expressed in BCG to obtain four rBCGs (BCG::CFP, BCG::FBP, BCG::PPE and BCG::INV). Both cellular and humoral immune responses induced by these r-BCG strains were evaluated in BALB/c mice after subcutaneous injection of a single dose of 1×10(6)CFU of the individual rBCGs. Compared to the parent BCG immunized animals the splenocytes derived from rBCG vaccinated groups showed greater antigen specific proliferation, characterized with higher IFN-γ response and reduced IL-4 secretion. Also rBCG vaccination was able to induce specific humoral immune response with an enhanced IgG2a/IgG1 ratio. The rBCGs therefore favor an epitope specific Th1 type response, which is known to be important for mycobacterial immunity. Further when two of the rBCGs (BCG::CFP and BCG::FBP) were tested for their protective efficacy both the rBCGs were comparable to BCG in a H37Rv challenge study performed in guinea pigs.  相似文献   
73.
Ueno N  Dube MG  Inui A  Kalra PS  Kalra SP 《Endocrinology》2004,145(9):4176-4184
We tested the hypothesis that leptin acts centrally and peripherally by different mechanisms to control peripheral hormones that normally regulate weight homeostasis. The paradigm of selectively increasing leptin transgene expression with a single intracerebroventricular injection of adeno-associated viral vectors encoding leptin (rAAV-lep) or green fluorescent protein (control) in the hypothalamus of mutant leptin-deficient ob/ob and wild-type (wt) mice was employed in these experiments. rAAV-lep injection increased hypothalamic leptin expression in the complete absence of peripheral leptin in ob/ob mice; suppressed body weight and adiposity; voluntarily decreased dark-phase food intake; suppressed plasma levels of adiponectin, TNFalpha, free fatty acids and insulin, concomitant with normoglycemia; and elevated ghrelin levels for extended period. Body weight and plasma levels of leptin and metabolic variables were suppressed to a lesser extent in rAAV-lep wt mice without decreasing food intake. The sustained high leptin transgene expression decreased only the dark-phase phagia in both genotypes, but wt mice escaped from leptin restraint during the lights-on phase, resulting in normal overall food intake. Leptin administration rapidly decreased plasma gastric ghrelin and adipocyte adiponectin but not TNFalpha levels, thereby demonstrating a peripheral restraining action of leptin on the secretion of hormones of varied origins. Whereas ghrelin administration readily stimulated feeding in controls, it was completely ineffective in rAAV-lep-treated wt mice. Thus, leptin expressed locally in the hypothalamus counteracted the central orexigenic effects of peripheral ghrelin. Cumulatively, these results identify newer central and peripheral modulatory influences of leptin on hormonal signals of disparate origin implicated in weight homeostasis and metabolic disorders.  相似文献   
74.
SETTING: Governmental health facilities in six districts of India. OBJECTIVE: To estimate the prevalence of cough and to compare the detection of smear-positive tuberculosis (TB) among out-patients with cough of > or =2 or > or =3 weeks. DESIGN: Trained health workers questioned each out-patient for presence of cough. Those with cough > or =2 weeks underwent sputum microscopy. RESULTS: Of 55561 out-patients interviewed, 2210 (4%) had cough > or =2 weeks, of whom 267 had sputum-positive TB, compared to 182/1370 with cough > or =3 weeks. The 31% who did not spontaneously complain of cough were less likely to be sputum-positive than those who did (45/680 [7%] vs. 222/1530 [15%], P < 0.001), but they accounted for 45/267 smear-positive cases. Using cough > or =2 weeks as the screening criterion, the estimated number of smears performed per day at each primary and secondary health care facility was respectively 8 and 19, compared to 5 and 12 using cough > or =3 weeks. CONCLUSION: The detection of smear-positive TB cases can be substantially improved by actively eliciting history of cough from all out-patients, and by changing the screening criterion for performing sputum microscopy among out-patients from cough > or =3 weeks to > or =2 weeks. Before implementing this change nationally, its programmatic feasibility should be assessed.  相似文献   
75.
Abstract Electrical impedance myography (EIM), a non-invasive, electrophysiological technique, has preliminarily shown value as an ALS biomarker. Here we perform a multicenter study to further assess EIM's potential for tracking ALS. ALS patients were enrolled across eight sites. Each subject underwent EIM, handheld dynamometry (HHD), and the ALS Functional Rating Scale-revised (ALSFRS-R) regularly. Techniques were compared by assessing the coefficient of variation (CoV) in the rate of decline and each technique's correlation to survival. Results showed that in the 60 patients followed for one year, EIM phase measured from the most rapidly progressing muscle in each patient had a CoV in the rate of decline of 0.62, compared to HHD (0.82) and the ALSFRS-R (0.74). Restricting the measurements to the first six months gave a CoV of 0.55 for EIM, 0.93 for HHD, and 0.84 for ALSFRS-R. For both time-periods, all three measures correlated with survival. Based on these data, a six-month clinical trial designed to detect a 20% treatment effect with 80% power using EIM would require only 95 patients/arm compared to the ALSFRS-R, which would require 220 subjects/arm. In conclusion, EIM can serve as a useful ALS biomarker that offers the prospect of greatly accelerating phase 2 clinical trials.  相似文献   
76.
Simmondsia chinensis (Link) Schneider is a dioecious shrub in which female plants are economically more important than the male plants, as seeds produced by the female plants store liquid wax ester that is extensively used in cosmetic industry. Sex of jojoba individuals can be determined only at flowering stage which comes after 3–4 years of seeding. Since, population of jojoba is male biased, so, to identify female plants at seedling stage, more reliable and robust male-specific sequence characterized amplified region marker was developed from male-specific inter-simple sequence repeat marker. During homology searching, no DNA sequence with significant similarity to male-specific inter-simple sequence repeat marker was found in non-redundant database of National Center for Biotechnology Information. Sequence characterized amplified region primer pair designed, based on the sequence of inter-simple sequence repeat marker, (GenBank accession no. HQ166029.1) amplified a fragment approx. 1000 bp in male plants only. This fragment was completely absent in female plants. Authentication of marker was done by using samples taken from two provinces of India.  相似文献   
77.
Effects of the tumor promoter 12-O-tetradecanoyl-phorbol-13-acetate (TPA) and protein kinase C (PKC) inhibitors on cell-cell communication were studied in a normal rat liver cell line, clone 9. Communication was observed and quantitated with microspectrofluorometric and image analysis techniques following scrape-loading of the cells with lucifer yellow. Lucifer yellow migrated as far as ten cells away from the scraped edge in control populations. Two minute TPA (25–50 μg/ml) treatment inhibited dye movement such that the dye remained mainly in the cells at the cut edge. The TPA-induced inhibition of cell-cell communication could be partially blocked by 15 min treatment of the cell populations with the PKC inhibitors trifluoperazine (30 μg/ml), staurosporine (2 × 10?8 or 2 × 10?6 M), sangivamycin (15 or 200 μM), or a PKC inhibitor peptide (20 μg/ml) scraped in at the same time as lucifer yellow. Normal communication was observed in cultures treated only with PKC inhibitors. Lower concentrations of TPA (50 ng/ml-1 μg/ml) used for 2 min did not inhibit dye communication. Our results demonstrate the phorbol ester-induced interruption of cell-cell communication. The inhibition of PKC by inhibitors eliminates the effect of TPA on communication. Our data are consistent with a role of PKC in the control of junctional communication. © 1993 Wiley-Liss, Inc.  相似文献   
78.
79.
80.
Fifteen cases with malarial infection were studied for hematological complications. Thrombocytopenia was observed with P. vivax infection. This complication is otherwise regarded as uncommon with P. vivax malaria. Possible mechanism and effects thereof are discussed.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号