全文获取类型
收费全文 | 211945篇 |
免费 | 3061篇 |
国内免费 | 230篇 |
专业分类
耳鼻咽喉 | 1557篇 |
儿科学 | 7339篇 |
妇产科学 | 3342篇 |
基础医学 | 21147篇 |
口腔科学 | 2559篇 |
临床医学 | 14947篇 |
内科学 | 40146篇 |
皮肤病学 | 1499篇 |
神经病学 | 19160篇 |
特种医学 | 10332篇 |
外科学 | 34662篇 |
综合类 | 2534篇 |
一般理论 | 1篇 |
预防医学 | 19327篇 |
眼科学 | 3241篇 |
药学 | 12447篇 |
中国医学 | 697篇 |
肿瘤学 | 20299篇 |
出版年
2023年 | 282篇 |
2022年 | 570篇 |
2021年 | 957篇 |
2020年 | 460篇 |
2019年 | 666篇 |
2018年 | 22594篇 |
2017年 | 17931篇 |
2016年 | 20137篇 |
2015年 | 1701篇 |
2014年 | 1842篇 |
2013年 | 1990篇 |
2012年 | 8790篇 |
2011年 | 22815篇 |
2010年 | 19822篇 |
2009年 | 12355篇 |
2008年 | 20980篇 |
2007年 | 23234篇 |
2006年 | 2189篇 |
2005年 | 3879篇 |
2004年 | 4902篇 |
2003年 | 5768篇 |
2002年 | 3940篇 |
2001年 | 1496篇 |
2000年 | 1764篇 |
1999年 | 1359篇 |
1998年 | 622篇 |
1997年 | 518篇 |
1996年 | 406篇 |
1995年 | 370篇 |
1994年 | 355篇 |
1993年 | 312篇 |
1992年 | 845篇 |
1991年 | 809篇 |
1990年 | 855篇 |
1989年 | 855篇 |
1988年 | 762篇 |
1987年 | 677篇 |
1986年 | 631篇 |
1985年 | 601篇 |
1984年 | 463篇 |
1983年 | 353篇 |
1982年 | 212篇 |
1980年 | 199篇 |
1979年 | 287篇 |
1978年 | 231篇 |
1977年 | 177篇 |
1974年 | 184篇 |
1970年 | 164篇 |
1969年 | 191篇 |
1968年 | 165篇 |
排序方式: 共有10000条查询结果,搜索用时 154 毫秒
991.
Satoshi Yamagiwa Yuh Kuwano Katsuhiko Hasegawa Kazunari Sato Kazuo Ohtsuka Tsuneo Iiai Katsuhiro Tomiyama Hisami Watanabe Satoshi Sugahara Shuhji Seki Hitoshi Asakura Toru Abo 《European journal of immunology》1996,26(7):1409-1416
Mice carrying the lpr gene, SCG and MRL-lpr/lpr mice, were used to characterize the phenotype and lpr gene of abnormally proliferating T cells in these mice. A major population which expanded in these mice were T cells expressing intermediate (int) levels of T cell receptor (TCR) (and CD3) and the phenotype of interleukin-2 receptor (IL-2R)βlo α? (possibly abnormal TCRint cells). The levels of TCRhi cells of thymic origin (generated through the mainstream of T cell differentiation in the thymus) profoundly decreased after the onset of disease. However, a small population of normal TCRint cells (i.e. IL-2Rβhi α?) were also found to exist in all tested organs. For example, the majority of abnormal IL-2Rβlo TCRint cells were CD4?8? CD2?, while normal IL-2Rβhi TCRint cells were a mixture of single-positive cells (mainly CD8+), CD4?8? cells and CD2+ cells. Moreover, normal TCRint cells preferentially produced normal Fas mRNA and Fas molecules from the lpr gene. This phenomenon explains the leaky appearance of normal Fas mRNA and Fas molecules in mice carrying the lpr gene. It is suggested that a small population of IL-2RβhiTCRint cells are resistant to the lpr genetic abnormality. 相似文献
992.
Prevention of endotoxin shock by an antibody against leukocyte integrin {beta}2 through inhibiting production and action of TNF 总被引:2,自引:0,他引:2
Watanabe Shun-ichi; Mukaida Naofumi; Ikeda Naoki; Akiyama Mariko; Harada Akihisa; Nakanishi Isao; Nariuchi Hideo; Watanabe Yoh; Matsushima Kouji 《International immunology》1995,7(7):1037-1046
Septic shock remains a serious disorder associated with highmortality. Accumulating evidence indicates that TNF is a majorand essential mediator of endotoxin shock. We report here thatadministration of an antibody against CD18 dramatically reducedendotoxin-induced shock inrabbits as revealed by preventionof severe hypotension, metabolic acidosis and a pathologicalchange suggestive of disseminated intravascular coagulationwith concomitant inhibition of elevation of plasma TNF activity.The anti-CD18 antibody also inhibited the hypotension inducedby administering recombinant TNF. Furthermore, an antibody againsta ligand for CD18 complexes, intercellular adhesion molecule-1,also prevented TNF-induced shock as well as endotoxin shockinrabbits. These observations suggest that adhesion of leukocytesto endothelium may be of primary importance in the action ofTNF as well as in the production of TNF in vivo and that theantibody against adhesion molecules could be of therapeuticbenefit in life-threatening septic shock in humans. 相似文献
993.
Keiko Wakui Toshiro Nishida Jun-ichiro Masuda Takeshi Itoh Daisuke Katsumata Tsutomu Ohno Yoshimitsu Fukushima 《Journal of human genetics》1991,36(2):149-153
We report a malformed female infant withde novo interstitial deletion of 4q[46,XX,del(4)(q27q28.2)]. The MN blood type analysis of the family members showed that the patient had an intact blood group-MN locus. The locus of the gene responsible for the MN antigen activity is confined to a 4q28.2–4q31.1 segment on the basis of the result of this patient and the previous mapping data. 相似文献
994.
995.
Yasuko Tomizawa Asako Tokumine Shinji Ninomiya Naoki Momose Toru Matayoshi 《Journal of artificial organs》2008,11(3):117-122
The heart-lung machines for open-heart surgery have improved over the past 50 years; they rarely break down and are almost always equipped with backup batteries. The hand-cranking procedure only becomes necessary when a pump breaks down during perfusion or after the batteries have run out. In this study, the performance of hand cranking a roller pump was quantitatively assessed by an objective method using the ECCSIM-Lite educational simulator system. A roller pump connected to an extracorporeal circuit with an oxygenator and with gravity venous drainage was used. A flow sensor unit consisting of electromagnetic sensors was used to measure arterial and venous flow rates, and a built-in pressure sensor was used to measure the water level in the reservoir. A preliminary study of continuous cranking by a team of six people was conducted as a surprise drill. This system was then used at a perfusion seminar. At the seminar, 1-min hand-cranking drills were conducted by volunteers according to a prepared scenario. The data were calculated on site and trend graphs of individual performances were given to the participants as a handout. Preliminary studies showed that each person's performance was different. Results from 1-min drills showed that good performance was not related to the number of clinical cases experienced, years of practice, or experience in hand cranking. Hand cranking to maintain the target flow rate could be achieved without practice; however, manipulating the venous return clamp requires practice. While the necessity of performing hand cranking during perfusion due to pump failure is rare, we believe that it is beneficial for perfusionists and patients to include hand-cranking practice in periodic extracorporeal circulation crisis management drills because a drill allows perfusionists to mentally rehearse the procedures should such a crisis occur. 相似文献
996.
Background
Genetic polymorphisms of the TCF7L2 gene are strongly associated with large increments in type 2 diabetes risk in different populations worldwide. In this study, we aimed to confirm the effect of the TCF7L2 polymorphism rs7903146 on diabetes risk in a Brazilian population and to assess the use of this genetic marker in improving diabetes risk prediction in the general population. 相似文献997.
Tanabe A Tsuiki M Watanabe D Takagi S Takano K Naruse M 《Rinsho byori. The Japanese journal of clinical pathology》2004,52(8):704-710
Aldosterone is one the representative cardiovascular hormones involved in the blood pressure and body-fluid homeostasis. Elevation of aldosterone leads to systemic hypertension through its action on the mineralocorticoid receptor (MR) in the kidney. More recent studies demonstrated that aldosterone may produce target organ damage through its direct actions on the non-epithelial MR of the heart in addition to its systemic effects. Clinical experience in primary aldosteronism supports the concept that aldosterone is a risk factor of cardiovascular complications, since concentric type of cardiac hypertrophy is most common in primary aldosteronism among various types of endocrine hypertension. Clinical mega-trial in congestive heart failure (RALES study, EPHESUS study) demonstrated blocking angiotensin II action is not sufficient for cardioprotection unless aldosterone action is equally blocked. An important phenomenon related to this issue is the aldosterone breakthrough which implies a reelevation of plasma aldosterone during chronic administration of ACE inhibitors and Angiotensin receptor antagonists. Normal level of aldosterone could still be a risk factor. Combination of ACE inhibitor or ARB with aldosterone antagonist could result in a better cardioprotection in cardiovascular diseases. Although spironolactone has been the only one aldosterone antagonist, a new antagonist eplerenone has been developed. Eplerenone is specific to MR and is practically devoid of the major side effect gynecomastia of spironolactone. Another topic of aldosterone is its very quick cardiovascular effect presumably via a non-genomic action. All these recent findings support that this adrenocortical steroid hormone is as important as angiotensin II. Determining aldosterone levels is therefore much morel important than before in the diagnosis and treatment of cardiovascular diseases. 相似文献
998.
Chiaki Watanabe Makiko Kuwagata Shinsuke Yoshimura Jiro Azegami Kouichi Kojima Hiroshi Ono Tetsuji Nagao 《Clinical genetics》2003,43(3):177-179
ABSTRACT The technique for gavage administration to rat nurslings was improved to allow determination of the direct effects of chemical substances in the nurslings. Rat neonates were treated with distilled water from postnatal day 1 through 20 using this technique. The viability of neonates during the administration period was comparable to that of untreated neonates. No adverse effects of this technique on the development of neonates were found, and no histological alterations of the esophagus or pharynx. Therefore, we conclude that use of our improved gavage administration method will contribute to ensuring successful neonatal development and thus allowing accurate assessment of the toxicological effects of test compounds on rat nurslings. 相似文献
999.
Karine Bollérot Daisuke Sugiyama Virginie Escriou Rodolphe Gautier Samuel Tozer Daniel Scherman Thierry Jaffredo 《Developmental dynamics》2006,235(1):105-114
We report here a method that allows fast, efficient, and low-cost screening for gene function in the vascular system of the vertebrate embryo. Through intracardiac delivery of nucleic acids optimally compacted by a specific cationic lipid, we are able to induce in vivo endothelial cell-specific gain-of-function during development of the vascular network in the chick embryo. When the nucleic acids are delivered during the period of intraembryonic hematopoiesis, aortic hemangioblasts, the forerunners of the hematopoietic stem cells known to derive from the aortic endothelium, are also labeled. Similarly, we show that siRNA could be used to induce loss-of-function in vascular endothelial cells. This gene transfer technique was also applied to the mouse embryo with a high efficiency. The present method allows large-scale analysis and may represent a new and versatile tool for functional genomics. 相似文献
1000.
Stone VE 《Current HIV/AIDS reports》2005,2(4):189-193
Racial/ethnic minorities in the United States are disproportionately affected by HIV/AIDS. In addition to having higher rates
of HIV/AIDS, minorities with HIV/AIDS have higher mortality rates than others in the United States. Disparities in the care
received by minorities living with HIV/AIDS contribute to these higher mortality rates. This article provides a review of
HIV/AIDS health care disparities and explores providers’ contributions to these disparities. An important source of provider
contribution to disparities appears to be differential prescribing based on perceptions and assumptions that minority patients
may have lower adherence to highly active antiretroviral therapy. Literature regarding this topic is reviewed and strategies
for reducing disparities are suggested. 相似文献