全文获取类型
收费全文 | 37966篇 |
免费 | 3638篇 |
国内免费 | 1445篇 |
专业分类
耳鼻咽喉 | 338篇 |
儿科学 | 636篇 |
妇产科学 | 613篇 |
基础医学 | 5444篇 |
口腔科学 | 1028篇 |
临床医学 | 3572篇 |
内科学 | 6644篇 |
皮肤病学 | 654篇 |
神经病学 | 2906篇 |
特种医学 | 1437篇 |
外国民族医学 | 3篇 |
外科学 | 4720篇 |
综合类 | 3923篇 |
一般理论 | 12篇 |
预防医学 | 2565篇 |
眼科学 | 851篇 |
药学 | 3668篇 |
7篇 | |
中国医学 | 1079篇 |
肿瘤学 | 2949篇 |
出版年
2023年 | 247篇 |
2022年 | 498篇 |
2021年 | 952篇 |
2020年 | 654篇 |
2019年 | 675篇 |
2018年 | 985篇 |
2017年 | 836篇 |
2016年 | 782篇 |
2015年 | 985篇 |
2014年 | 1223篇 |
2013年 | 1439篇 |
2012年 | 1991篇 |
2011年 | 1967篇 |
2010年 | 1231篇 |
2009年 | 1050篇 |
2008年 | 1608篇 |
2007年 | 1717篇 |
2006年 | 1464篇 |
2005年 | 1293篇 |
2004年 | 1100篇 |
2003年 | 1014篇 |
2002年 | 860篇 |
2001年 | 2412篇 |
2000年 | 2290篇 |
1999年 | 1910篇 |
1998年 | 730篇 |
1997年 | 511篇 |
1996年 | 371篇 |
1995年 | 316篇 |
1994年 | 271篇 |
1993年 | 239篇 |
1992年 | 1037篇 |
1991年 | 913篇 |
1990年 | 809篇 |
1989年 | 897篇 |
1988年 | 820篇 |
1987年 | 747篇 |
1986年 | 704篇 |
1985年 | 610篇 |
1984年 | 383篇 |
1983年 | 318篇 |
1982年 | 185篇 |
1981年 | 138篇 |
1980年 | 117篇 |
1979年 | 203篇 |
1978年 | 84篇 |
1973年 | 93篇 |
1972年 | 92篇 |
1971年 | 94篇 |
1968年 | 83篇 |
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
51.
52.
53.
J Chhabra Y-Z Li H Alkhouri A E Blake Q Ge C L Armour J M Hughes 《The European respiratory journal》2007,29(5):861-870
Degranulating mast cells are increased in the airway smooth muscle (ASM) of asthmatics, where they may influence ASM function. The aim of the present study was to determine whether histamine and tryptase modulate ASM cell granulocyte-macrophage colony-stimulating factor (GM-CSF) and RANTES (regulated on activation, normal T-cell expressed and secreted) release and also to examine which receptors are involved in this release. Confluent, quiescent ASM cells from asthmatic and nonasthmatic donors were treated with histamine (1 microM-100 microM) with and without histamine receptor antagonist pre-treatment, or the protease-activated receptor (PAR)-2 agonists tryptase (0.5-5 nM) and SLIGKV (100 and 400 microM). The cells were then stimulated with interleukin (IL)-1beta and/or tumour necrosis factor (TNF)-alpha (10 ng.mL(-1)) or left unstimulated for 24 h. Release of GM-CSF and RANTES was determined by ELISA and prostaglandin (PG)E(2) measured by enzyme immunoassay. Neither histamine nor tryptase induced ASM GM-CSF or RANTES secretion. However, histamine increased IL-1beta-induced GM-CSF release and markedly reduced TNF-alpha-induced RANTES release by both asthmatic and nonasthmatic cells to a similar extent, but did not modulate PGE(2) release. All changes involved activation of the histamine H1 receptor as they were partially or fully blocked by chlorpheniramine, but not ranitidine. Tryptase, via its proteolytic activity, also potentiated GM-CSF, but not RANTES, release from asthmatic and nonasthmatic ASM cells induced by both cytokines. PAR-2 involvement in the tryptase potentiation was unlikely because SLIGKV had no effect. In conclusion, mast cells, through histamine and tryptase, may locally modulate airway smooth muscle-induced inflammation in asthma. 相似文献
54.
55.
56.
Internal Hernias: Clinical Findings,Management, and Outcomes in 49 Nonbariatric Cases 总被引:1,自引:0,他引:1
Saber Ghiassi Scott Q. Nguyen Celia M. Divino John C. Byrn Avraham Schlager 《Journal of gastrointestinal surgery》2007,11(3):291-295
Internal hernia, the protrusion of a viscus through a peritoneal or mesenteric aperture, is a rare cause of small bowel obstruction.
We report the clinical presentation, surgical management, and outcomes of one of the largest series of nonbariatric internal
hernias. Ten-year retrospective review of patients at our institution yielded 49 cases of internal hernias. Majority of patients
presented with symptoms of acute (75%) or intermittent (22%) small bowel obstruction. While 16% of CT scans were suspicious
for internal hernia, in no cases the preoperative diagnosis of internal hernia was made. The most frequent internal hernias
were transmesenteric (57.0%) and 34 hernias (69%) were caused by previous surgery. All internal hernias were reduced and the
defects were repaired. Compromised bowel was present in 22 cases and 11 patients underwent small bowel resection. The mean
postoperative hospitalization was 10.9 days. The overall mortality rate from our series is 2%, and the morbidity rate is 12%.
Transmesenteric hernias, as complications of previous surgeries, are the most prevalent internal hernias. Preoperative diagnosis
of internal hernia is extremely difficult because of the nonspecific clinical presentation. However, if discovered promptly,
internal hernias can be repaired with acceptable morbidity and mortality.
Poster presentation at Digestive Disease Week, May 22, 2006, Los Angeles, California, USA. 相似文献
57.
58.
This paper reports the morphometric analysis results of 100 cases of bladder tumor cells with a Q-900 computer-assisted image analysis system. According to the nuclear area, axis ratio and area ratio of tumor nuclei, bladder transitional cell tumors were divided into 4 grades. This system is called the morphometric grading system (M grading). The results show that the higher the M grading, the lower the survival rate and the higher the recurrence rate. As the M grade increases the tumors could be accompanied by muscular invasion. When recurring, the tumor has a poor prognosis if M grading increases. We conclude that the morphometric grading system is able to yield a quantitative pathologic diagnosis and can predict the biological behavior of bladder tumors. Recently, new techniques for diagnosing and predicting the biological behavior of bladder tumors have been developed. One such technique is morphometric analysis of bladder transitional cell carcinoma with computer-assisted image instruments [1]. Because this morphometric method is easily applicable to pathological section routinely stained with HE and the results are reproducible and more objective, the studies about morphometric analysis of bladder tumor have increased in recent times. This paper reports the preliminary morphometric analysis results of bladder tumor cells examined by a Q-900 image analysis instrument for 100 cases. 相似文献
59.
60.