全文获取类型
收费全文 | 11922篇 |
免费 | 1149篇 |
国内免费 | 317篇 |
专业分类
耳鼻咽喉 | 24篇 |
儿科学 | 177篇 |
妇产科学 | 134篇 |
基础医学 | 3130篇 |
口腔科学 | 145篇 |
临床医学 | 687篇 |
内科学 | 1930篇 |
皮肤病学 | 90篇 |
神经病学 | 1470篇 |
特种医学 | 162篇 |
外国民族医学 | 1篇 |
外科学 | 680篇 |
综合类 | 1129篇 |
现状与发展 | 3篇 |
一般理论 | 1篇 |
预防医学 | 953篇 |
眼科学 | 112篇 |
药学 | 1207篇 |
2篇 | |
中国医学 | 550篇 |
肿瘤学 | 801篇 |
出版年
2024年 | 48篇 |
2023年 | 221篇 |
2022年 | 266篇 |
2021年 | 496篇 |
2020年 | 425篇 |
2019年 | 423篇 |
2018年 | 400篇 |
2017年 | 445篇 |
2016年 | 476篇 |
2015年 | 557篇 |
2014年 | 691篇 |
2013年 | 874篇 |
2012年 | 671篇 |
2011年 | 689篇 |
2010年 | 622篇 |
2009年 | 637篇 |
2008年 | 616篇 |
2007年 | 531篇 |
2006年 | 482篇 |
2005年 | 412篇 |
2004年 | 386篇 |
2003年 | 285篇 |
2002年 | 247篇 |
2001年 | 230篇 |
2000年 | 205篇 |
1999年 | 152篇 |
1998年 | 161篇 |
1997年 | 125篇 |
1996年 | 148篇 |
1995年 | 134篇 |
1994年 | 97篇 |
1993年 | 111篇 |
1992年 | 98篇 |
1991年 | 78篇 |
1990年 | 71篇 |
1989年 | 83篇 |
1988年 | 88篇 |
1987年 | 46篇 |
1986年 | 63篇 |
1985年 | 72篇 |
1984年 | 92篇 |
1983年 | 47篇 |
1982年 | 77篇 |
1981年 | 58篇 |
1980年 | 57篇 |
1979年 | 50篇 |
1978年 | 34篇 |
1977年 | 29篇 |
1976年 | 40篇 |
1973年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Terry Reed 《Clinical genetics》1991,39(5):391-395
Evidence from the literature is reviewed to suggest that when fingertip dermal ridge patterns in chromosomal deletion syndromes are characteristic of the opposite spectrum of the developmental scale from patterns found in cases trisomic for the same chromosomal region, the association may be a consequence of loci with growth regulatory functions. Evidence is presented that DNA markers at 18q21 should be the first candidate sequences to be used to test this hypothesis in families with fingertip arches segregating in an apparent autosomal dominant fashion. 相似文献
22.
Howard Trachtman 《Pediatric nephrology (Berlin, Germany)》1992,6(1):104-112
Cerebral cell volume regulatory mechanisms are activated by sustained disturbances in plasma osmolality. Acute hypernatremia causes a predictable shrinkage of brain cells due to the sudden imposition of a plasma-to-cell osmolal gradient. However, during chronic hypernatremia cerebral cell volume is maintained close to the normal range as a result of the accumulation of electrolytes and organic osmolytes including myo-inositol, taurine, glutamine, glycerophosphorylcholine, and betaine. The increased cytosolic level of these molecules is generally accomplished via increased activity of sodium (Na+)-dependent cotransport systems. The slow dissipation of these additional osmotically active solutes from the cell during treatment of hypernatremia necessitates gradual correction of this electrolyte abnormality. Acute hyponatremia leads to cerebral cell swelling and severe neurological dysfunction. However, prolonged hyponatremia is associated with significant reductions in brain cell electrolyte and organic osmolyte content so that cerebral cell volume is restored to normal. While acute hyponatremia can be treated with the administration of moderate doses of hypertonic saline in order to control seizure activity, chronic hyponatremia should be corrected slowly in order to prevent subsequent neurological deterioration. If the rate of correction exceeds 0.5 mmol/l per hour, or if the total increment in serum [Na+] exceeds 25 mmol/l in the first 48 h of therapy, then there is an increased risk of the development of cerebral demyelinating lesions. Chronic hyperglycemia activates the brain cell volume regulatory adaptations in the same manner as hypernatremia. Therefore, during the treatment of diabetic ketoacidosis, it is imperative to restore normoglycemia gradually in order to prevent the occurrence of cerebral edema. It is possible that excessive administration of electrolyte-free solutions and high doses of insulin may increase the risk of this complication. While there are some data to suggest that brain cell size is disturbed during acute uremia, additional work is necessary to clarify the role of cerebral cell volume regulation during acute and chronic uremia. 相似文献
23.
建立新型医患关系是医院工作的当务之急 总被引:7,自引:5,他引:2
《医疗事故处理条例》《最高人民法院关于民事诉讼证据的若干规定》这两个法规的出台,给医院提出了新的课题,结合目前实际,提出了医院全面贯彻执行这两个法规,必须从围绕改善医患关系这个中心问题入手。建立新型和医患关系,并根据多年的观察与实践,着重论述了如下见解:医务人员在为患者的攻关服务过程中,要真正认识自己是医患矛盾中的主要方面;医务人员要转变传统的服务思维定势,尊重和理解患者,医务人员要确立既为患者生命和利益负责,又重视患者权利的观念,医务人员要增强法制观念,做到依法行医,医院要设置监控部门或配备专兼职人员,对全院的医疗服务进行检查监督。 相似文献
24.
Johannes Irsch Rudolf Hendriks Hans Tesch Ruud Schuurman Andreas Radbruch 《European journal of immunology》1993,23(2):481-486
In activated murine B lymphocytes, immunoglobulin class switch recombination occurs as a highly regulated process which is targeted to distinct switch regions. Here we present first evidence that in human B lymphocytes, switch recombination is targeted to distinct switch regions as well. In a panel of clonally unrelated IgG1-expressing human B cells, immortalized by Epstein-Barr virus (EBV) transformation, seven out of nine cells show switch recombination between Sμ and Sγ1 on both alleles, the active and inactive one. The remaining cells show no switch recombination on the inactive IgH locus. The very strong correlation of switch recombination on both alleles of IgG1-expressing cells proves that class switch recombination to IgG1 is not random but directed in human B lymphocytes. 相似文献
25.
26.
27.
Aim: Sodium/bicarbonate co‐transport (NBC) has been suggested to have a role in muscle pH regulation. We investigated the presence of NBC proteins in rat and human muscle samples and the fibre type distribution of the identified NBCs. Methods and results: Western blotting of muscle homogenates and sarcolemmal membranes (sarcolemmal giant vesicles) were used to screen for the presence of NBCs. Immunohistochemistry was used for the subcellular localization. The functional test revealed that approximately half of the pH recovery in sarcolemmal vesicles produced from rat muscle is mediated by bicarbonate‐dependent transport. This indicates that the NBCs are preserved in the vesicles. The western blotting experiments demonstrated the existence of at least two NBC proteins in skeletal muscle. One NBC protein (approximately 150 kDa) seems to be related to the kidney/pancreas/heart isoform NBC1, whereas the other protein (approximately 200 kDa) is related to the NBC4 isoform. The two NBC proteins represent the electrogenic isoforms named NBCe1 and NBCe2. Membrane fractionation and immunofluorescence techniques confirmed that the two NBCs are located in the sarcolemmal membrane as well as in some internal membranes, probably the T‐tubules. The two NBCs localized in muscle have distinct fibre type distributions. Conclusions: Skeletal muscle possesses two variants of the sodium/bicarbonate co‐transporter (NBC) isoforms, which have been called NBCe1 and NBCe2. 相似文献
28.
PCBP1:一种在多水平上参与基因表达调控的蛋白因子 总被引:1,自引:0,他引:1
多聚胞嘧啶结合蛋白1 (poly C binding protein-1,PCBP1),属于RNA结合蛋白亚家族,因其具有同RNA的多聚胞嘧啶(poly C)区域特异的结合活性而得名.目前该亚家族共有5个成员:hnRNP K(heterogeneous nuclear ribonucleoprotein K)、PCBP1、PCBP2、PCBP3和PCBP4.PCBP1蛋白在多个水平参与基因的表达调控,如转录、mRNA加工、mRNA的转运、mRNA稳定以及翻译水平调控等.本文对PCBP1基因的结构和生物学功能进行了综述. 相似文献
29.
30.
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