全文获取类型
收费全文 | 23444篇 |
免费 | 1455篇 |
国内免费 | 491篇 |
专业分类
耳鼻咽喉 | 146篇 |
儿科学 | 1167篇 |
妇产科学 | 1324篇 |
基础医学 | 2545篇 |
口腔科学 | 448篇 |
临床医学 | 1655篇 |
内科学 | 3367篇 |
皮肤病学 | 231篇 |
神经病学 | 2332篇 |
特种医学 | 371篇 |
外国民族医学 | 3篇 |
外科学 | 2511篇 |
综合类 | 3092篇 |
现状与发展 | 4篇 |
预防医学 | 1347篇 |
眼科学 | 127篇 |
药学 | 2388篇 |
13篇 | |
中国医学 | 860篇 |
肿瘤学 | 1459篇 |
出版年
2024年 | 47篇 |
2023年 | 222篇 |
2022年 | 526篇 |
2021年 | 746篇 |
2020年 | 606篇 |
2019年 | 574篇 |
2018年 | 584篇 |
2017年 | 678篇 |
2016年 | 679篇 |
2015年 | 663篇 |
2014年 | 1194篇 |
2013年 | 1469篇 |
2012年 | 1093篇 |
2011年 | 1301篇 |
2010年 | 1115篇 |
2009年 | 1025篇 |
2008年 | 1055篇 |
2007年 | 1037篇 |
2006年 | 1050篇 |
2005年 | 900篇 |
2004年 | 759篇 |
2003年 | 698篇 |
2002年 | 613篇 |
2001年 | 560篇 |
2000年 | 519篇 |
1999年 | 426篇 |
1998年 | 350篇 |
1997年 | 381篇 |
1996年 | 382篇 |
1995年 | 319篇 |
1994年 | 330篇 |
1993年 | 279篇 |
1992年 | 296篇 |
1991年 | 279篇 |
1990年 | 305篇 |
1989年 | 234篇 |
1988年 | 187篇 |
1987年 | 164篇 |
1986年 | 185篇 |
1985年 | 247篇 |
1984年 | 218篇 |
1983年 | 141篇 |
1982年 | 183篇 |
1981年 | 141篇 |
1980年 | 120篇 |
1979年 | 114篇 |
1978年 | 99篇 |
1977年 | 82篇 |
1976年 | 63篇 |
1975年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 21 毫秒
21.
D W Bowden K Lohman F-C Hsu C D Langefeld J J Carr L Lenchik L E Wagenknecht B I Freedman D M Herrington 《Diabetic medicine》2006,23(7):763-767
AIMS: Increased levels of inflammatory biomarkers, especially C-reactive protein (CRP), are associated with increased risk for cardiovascular disease (CVD) events, such as myocardial infarction, stroke, peripheral vascular disease, and sudden cardiac death. Medical interventions that increase CRP levels, such as hormone replacement therapy (HRT) in post-menopausal women, are under increasing scrutiny. The effect of HRT on CRP levels in women with Type 2 diabetes (T2DM) is not well documented, and conflicting conclusions have been reported. The aim of this study was to determine the influence of HRT on women with diabetes in a large cross-sectional study. METHODS: Three hundred and twenty-seven post-menopausal women with T2DM from the Diabetes Heart Study participated. Current use of HRT was determined and serum CRP levels were measured using a high-sensitivity ELISA kit. Generalized estimating equation methods were used to assess the relationship of multiple clinical and lifestyle (e.g. smoking) measures on CRP levels including differences between women taking HRT (HRT+) and not taking HRT (HRT-). RESULTS: Overall serum CRP levels were strongly associated with body mass index (P < 0.0001) and age (P < 0.0001). Of the women, 243 were not using HRT and 84 were using HRT. HRT+ and HRT- women did not differ significantly in measures of clinical traits, with the exception of higher mean low-density lipoprotein cholesterol in HRT- women (P = 0.004). In all models tested, HRT+ women had significantly higher circulating CRP levels, with P-values ranging from 0.0045 to 0.010. CONCLUSIONS: In this study of serum CRP concentration as a function of HRT in women with Type 2 diabetes, there was consistent evidence for increased circulating CRP levels in women receiving oestrogen-containing HRT. Whether HRT-induced increases in CRP can account for the adverse cardiovascular effects of HRT remains to be established; however, based on these data, there is little reason to believe that diabetic women would be spared from such an effect. 相似文献
22.
Objective To evaluate the bioequivalence between recombinant human growth hormone (rhGH) for reconstitution, and two dosages of liquid formulation of rhGH [ (151U) 5mg or (301U) lOmg per 3ml ]. Methods The study drugs were tested in a randomized, single-blind and three-period crossover studies in 24 healthy male subjects. The three drugs were administered by subcutaneous injection at a dose of O. 21U/kg body weight. A continuous somatostatin infusion was given in order to suppress the secretion of endogenous GH. The ve- nous blood samples were drawn at different time points to test the serum concentration of GH. The pharmacokinetic parameters were analyzed by statistical methods. Results 90% confidence intervals (CI) of AUC0-24h among three products were all within 80% - 125% interval ( 103. 4% - 116. 5%, 105. 7% - 119. 6% and 91.9% - 103. 7%, respectively), and the Cls of C,~ among three products were all within 70% - 143% interval (91.9% - 114. 0%, 103. 7% -127. 2% and 81.6% -97. 4%, respectively). There was no statisitical difference of tmax among all the three products. Conclusion These data demonstrate that there is bioequivalence between rhGH for reconstitution and two liquid formulations of rhGH. 相似文献
23.
Ts. V. Serbenyuk I. E. Gurskaya A. D. Slyuta G. Ya. Roze P. Ya. Romanovskii 《Bulletin of experimental biology and medicine》1988,106(1):931-933
Department of Physiology of Man and Animals, Biological Faculty, M. V. Lomonosov Moscow University. (Presented by Academician of the Academy of Medical Sciences of the USSR I. P. Ashmarin.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 106, No. 7, pp. 17–19, July, 1988. 相似文献
24.
Administration of antiserum to thyrotropin-releasing hormone (TRH) into the lateral cerebral ventricle of mice significantly attenuated recovery from hyperglycemia induced by treatment with 2-deoxyglucose but had no effect on the plasma glucose of saline-treated mice. TRH, injected centrally together with the anti-TRH antibody, reversed the effect of the antiserum and blocked the development of hyperglycemia. These findings suggest that activation of TRH neurons in the central nervous system may be a physiological event influencing recovery from hyperglycemia. 相似文献
25.
26.
J. N. Laverri re J. L. Richard A. Morin N. Buisson A. Tixier-Vidal W. B. Huttner D. Gourdji 《Molecular and cellular endocrinology》1991,80(1-3):41-51
Secretogranin I (SgI; chromogranin B) belongs to a class of acidic tyrosine-sulfated secretory proteins believed to play a role in the secretory process of endocrine cells. Our aim here was to compare the levels of SgI mRNA to that of prolactin (PRL) and growth hormone (GH), using rat pituitary cell lines. As far as the constitutive expression is concerned, we found a positive correlation between SgI mRNA and PRL mRNA levels. However, the neuropeptide TRH (50 nM) inhibited the accumulation of SgI mRNA in GH3B6 cells whereas, as expected, it induced a rapid and sustained increase in PRL mRNA accumulation. By contrast, 17β-estradiol (1 nM) stimulated the accumulation of both SgI and PRL mRNAs, with the same EC50 (18–59 pM). Reciprocally, treatment with dexamethasone (100 nM) reduced the level of SgI and PRL mRNAs to 23% and 29% of control, respectively, but led to a 2.1-fold increase in the GH mRNA level. Altogether, the present work shows that SgI gene expression is subject to multiple hormonal regulations and occasionally parallels the regulation of the PRL gene but never that of the GH gene, under the conditions tested. 相似文献
27.
A. Tchelet T. Vogel D. Helman R. Guy C. Neospouolus V. Goffin J. Djiane A. Gertler 《Molecular and cellular endocrinology》1997,130(1-2):141-152
A new analogue of recombinant human growth hormone (hGH), hGH des(1–6,14) was expressed in Escherichia coli, refolded and purified to homogeneity. The mutation decreased the hormone's ability to bind lactogenic and somatogenic receptors through its site 1, and almost completely abolished its ability to bind these receptors through site 2, as evidenced by both binding and gel-filtration experiments. More specifically, the binding to prolactin receptors (PRLRs) from various species or their soluble recombinant extracellular domains (ECDs) was decreased 1.5–4-fold, whereas the binding to hGH receptor (hGHR) was decreased 10–85-fold. These changes caused an almost total loss of hormone agonistic activity in several in vitro bioassays and subsequently, the hGH des(1–6,14) analogue acquired antagonistic properties. This antagonistic activity was dependent upon modification of site 1. In those cases in which the binding was reduced only slightly, e.g. binding to rabbit PRLRs, hGH des(1–6,14) acted as a strong antagonist, whereas in others in which the binding of site 1 was reduced to a higher degree, such as other PRLRs and, in particular, hGHR, the antagonistic activity was correspondingly weaker. Circular dichroism spectra of the analogue suggested that these changes do not result from a decrease in overall -helix content, but rather from minor local structural modifications at the N-terminus. 相似文献
28.
应用~(51)Cr释放试验和效靶结合试验,同时测定了正常人和胃癌病人外周血NK细胞活性与靶结合细胞数(TBC),研究了正常人及病人血浆对NK细胞功能的影响。发现正常人NK细胞活性与靶结合细胞数之间的关系呈直线正相关,但在NK活性降低的病人中靶结合细胞数却无明显改变,二者无相关性,而病人的血浆对正常人外周血NK活性则有明显的抑制作用(P<0.05),且抑制率与胃癌人NK细胞活性存有着负相关的关系,提示胃癌病人血浆具有抑制NK细胞活性的物质。 相似文献
29.
S. W. J. LAMBERTS P. UITTERLINDEN T. VERLEUN 《European journal of clinical investigation》1987,17(4):354-359
Abstract. Several conflicting reports have been published with regard to the relationships between circulating growth hormone (GH), Somatomedin-C (SM-C) levels and clinical activity during different stages of therapy of acromegaly. We did not find a significant correlation between (fasting, post-prandial and mean 24-h) plasma GH and SM-C concentrations in twenty-two untreated acromegalic patients. There was a statistical significant correlation, however, if only the GH levels below 100 μg l-1 were considered (n=18 patients, P<0·01). The distribution of molecular forms of GH (‘little’, ‘big’ and ‘big-big’) did not differ between the four patients with GH levels above 100 μg l-1 and in four patients with levels between 40 μg l-1 and 80 μg l-1. Therefore, it is suggested that GH levels of 80–100 μg l-1 maximally activate Somatomedin-C production in man and that further increases in GH in general will not result in a further increase in SM-C generation. There was a significant correlation between GH and SM-C levels in forty-nine acromegalic patients after surgery and/or radiotherapy (P<0·001). In twenty-three of thirty-one patients with elevated SM-C levels the disease was subjectively still active, while this was the case in none of the patients with normal SM-C levels. In eight patients the disease was considered not to be clinically active any more, despite slightly increased SM-C levels. During long-term therapy of ten acromegalic patients for 16–108 weeks (mean 66±10) with 200–300 μg Sandostatin subcutaneously, clinical activity of the disease disappeared well before mean 24–h GH and SM-C levels reached the normal levels. There was a close correlation between mean 24-h GH and SM-C levels during Sandostatin therapy (P<0·001). ‘Clinical cure’ during this medical treatment was reached in five patients, as reflected by disappearance of subjective complaints, normalization of SM-C levels and 24-h mean GH levels of 2·8±0·2 μg l-1. Conclusions: (i) in untreated acromegaly, circulating GH and SM-C levels correlate well up to GH concentrations of 100 μg l-1. A further increase in GH does not result in a corresponding further increase in SM-C levels, suggesting a maximally activated production, without further GH-dependent capacity. (ii) Clinical ‘cure’ of acromegaly often occurs before normalization of the circulating SM-C levels. (iii) The measurement of plasma SM-C concentrations can be used well to adjust the dose and frequency of Sandostatin administration in acromegaly. This avoids the need of measuring extensive 24-h GH profiles. 相似文献
30.
Tatsuo Uchida Takahiko Tokumaru Hiroshi Kojima Katsura Nakagawaji Munehisa Imaizumi Toshio Abe 《Surgery today》1992,22(3):265-268
A 36 year old woman was admitted to our department because of a chest X-ray which showed multiple developing shadows. She underwent bilateral exploratory thoracotomies and a total 5 tumors were resected and pathologically diagnosed as benign metastasizing leiomyoma, the largest of which was positive for the progesterone receptor and negative for the estrogen receptor. A histogram of this tumor using a flow cytometer showed a diploid pattern and 4.6 percent of the S phase which was not more than that of a leiomyoma of the uterus from another patient. Two months later, she underwent a hysterectomy and bilateral salpingo-oophorectomy for treatment of the positive progesterone receptor in the pulmonary lesions. The resected uterine myoma and normal myometrium showed positive estrogen and progesterone receptors. For the subsequent 28 months she has been free of any further symptoms. Benign metastasizing leiomyoma of the uterus is a rare disease and very interesting because of its histological benignity and hormonal dependency. However, according to the literature, it is often confused in entity due to the fact that normal lung tissue also possesses hormone receptors. Considering our data on hormone receptors, it is rational to think that multiple leiomyomatous lesions in the lung should only be diagnosed as benign metastasizing leiomyomas when they possess positive estrogen and progesterone receptors. 相似文献