全文获取类型
收费全文 | 2708篇 |
免费 | 129篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 32篇 |
儿科学 | 91篇 |
妇产科学 | 67篇 |
基础医学 | 423篇 |
口腔科学 | 89篇 |
临床医学 | 245篇 |
内科学 | 517篇 |
皮肤病学 | 61篇 |
神经病学 | 272篇 |
特种医学 | 56篇 |
外科学 | 291篇 |
综合类 | 15篇 |
一般理论 | 2篇 |
预防医学 | 247篇 |
眼科学 | 33篇 |
药学 | 261篇 |
中国医学 | 8篇 |
肿瘤学 | 140篇 |
出版年
2023年 | 29篇 |
2022年 | 45篇 |
2021年 | 83篇 |
2020年 | 46篇 |
2019年 | 59篇 |
2018年 | 67篇 |
2017年 | 57篇 |
2016年 | 56篇 |
2015年 | 56篇 |
2014年 | 87篇 |
2013年 | 144篇 |
2012年 | 209篇 |
2011年 | 200篇 |
2010年 | 115篇 |
2009年 | 89篇 |
2008年 | 150篇 |
2007年 | 192篇 |
2006年 | 191篇 |
2005年 | 158篇 |
2004年 | 153篇 |
2003年 | 132篇 |
2002年 | 136篇 |
2001年 | 20篇 |
2000年 | 17篇 |
1999年 | 18篇 |
1998年 | 24篇 |
1997年 | 13篇 |
1996年 | 15篇 |
1995年 | 13篇 |
1994年 | 15篇 |
1993年 | 7篇 |
1992年 | 13篇 |
1991年 | 22篇 |
1990年 | 16篇 |
1989年 | 18篇 |
1988年 | 16篇 |
1987年 | 10篇 |
1986年 | 13篇 |
1985年 | 15篇 |
1983年 | 9篇 |
1982年 | 10篇 |
1981年 | 7篇 |
1980年 | 11篇 |
1979年 | 9篇 |
1978年 | 11篇 |
1977年 | 8篇 |
1976年 | 11篇 |
1975年 | 8篇 |
1974年 | 5篇 |
1967年 | 6篇 |
排序方式: 共有2850条查询结果,搜索用时 15 毫秒
1.
Increasing evidence suggests that human epidermal melanocytes play an important role in the skin immune system; however, a role of their pigmentation in immune and inflammatory responses is poorly examined. In the study, the expression of Toll‐like receptor 4 (TLR4) and inflammatory cytokines and chemokines by cultured normal melanocytes derived from lightly and darkly pigmented skin was investigated after cell stimulation with lipopolysaccharide (LPS). The basal TLR4 mRNA level in heavily pigmented cells was higher as compared to their lightly pigmented counterparts. Melanocyte exposure to LPS upregulated the expression of TLR4 mRNA and enhanced the DNA‐binding activity of NF‐κB p50 and p65. We found substantial differences in the LPS‐stimulated expression of numerous genes encoding inflammatory cytokines and chemokines between the cells with various melanin contents. In lightly pigmented melanocytes, the most significantly upregulated genes were nicotinamide phosphoribosyltransferase (NAMPT/visfatin), the chemokines CCL2 and CCL20, and IL6, while the genes for CXCL12, IL‐16 and the chemokine receptor CCR4 were the most significantly upregulated in heavily pigmented cells. Moreover, the lightly pigmented melanocytes secreted much more NAMPT, CCL2 and IL‐6. The results of our study suggest modulatory effect of melanogenesis on the immune properties of normal epidermal melanocytes. 相似文献
2.
G Oberhuber T Schmid R Erdk?nig W Thaler D Ofner G K?r?szi G Klima R Margreiter 《European surgical research. Europ?ische chirurgische Forschung. Recherches chirurgicales européennes》1991,23(3-4):206-213
The effect of ciclosporin (CS) and methotrexate (MTX) on the development of graft-versus-host (GvH) disease was examined after small bowel allotransplantation in the rat. The drugs were tested either alone or in combination. Lewis small bowel allografts were transplantated into Brown Norway recipients in a heterotopic position. The native small bowel, spleen, liver, skin, mesenteric lymph nodes and the kidney of the recipients were examined histologically 5, 10 and 20 days after allotransplantation. Intraepithelial lymphocyte numbers were determined quantitatively in the native small bowel. The relative spleen weight of the host was determined after sacrifice for estimation of the severity of GvH disease. Grade I GvH reaction of the native small bowel occurred in the animals without immunosuppression, but graft rejection predominated in this group. Treatment with CS was effective in the early postoperative periods; after 10 and 20 days GvH lesions in the native small bowel were comparable to those observed in the allogeneic combinations. MTX had a detrimental effect on the allografts and the GvH reaction was augmented. When CS and MTX were combined, GvH lesions were comparable to those in the animals treated solely with CS. Animals, however, suffered from heavy side effects. The spleen, liver, lymph nodes and kidney exhibited only unspecific histologic changes, which could not unequivocally be recognized as a GvH reaction. This was true for all groups. As a conclusion it can be said that GvH reaction occurs in the early postoperative period in a fully allogeneic model and cannot be prevented by CS in the dosae used. MTX was not seen to be of any value in this regard. 相似文献
3.
4.
5.
6.
7.
U. Klima R. Mair C. Groß R Peschl G. Wimmer-Greinecker Prof. Dr. P. Brücke 《Langenbeck's archives of surgery / Deutsche Gesellschaft fur Chirurgie》1994,379(2):120-122
We report on a 52-year old male patient who underwent implantation of an insulin pump because he had diabetes and in whom superior vena cava syndrome developed as a long-term complication. After unsuccessful lysis therapy superficial femoral vein was implanted to form a bypass from the internal jugular vein to the right atrium. The postoperative course was uneventful from the aspects of both the bypass and the leg after explantation of the superficial femoral vein. The bypass is still patent 7 months after the operation, and the patient has no symptoms. Autogenous superficial femoral vein can be used successfully in the reconstruction of large venous vessels. It should be the graft of choice for young patients with benign diseases. We compare our result and those obtained with different substitutes described in the literature that have been used for reconstruction in superior vena cava syndrome.
Die verwendung der autologen vena femoralis bei vena-cava-superior-thromboseFallbericht mit literaturübersicht
Zusammenfassung Bei einem 52jährigen, männlichen Patienten trat nach Implantation einer Insulinpumpe als Spätkomplikation eine Thrombose der Vena cava superior auf. Nach erfolgloser Lysetherapie wurde ein Venajugularis-rechtsatrialer-Venenbypass mit autologer Vena femoralis durchgeführt. Der postoperative Heilungsverlauf war sowohl von Seiten des gefäßrekonstruktiven Eingriffs, als auch von Seiten der Venenentnahmestelle komplikationslos. Der Bypass ist 7 Monate postoperativ offen und der Patient beschwerdefrei. Die autologe Vena femoralis eignet sich zur Rekonstruktion großer venöser Gefäße ausgezeichnet. Sie sollte v. a. bei benignen Prozessen und jüngeren Patienten als autologes Bypassmaterial dem Kunststoff vorgezogen werden. Das Ergebnis wird mit verschiedenen Gefäßsubstituten, die bei Verschluß der oberen Hohlvene verwendet werden, verglichen.相似文献
8.
9.
Efrat Rorman Chen Stein Zamir Irena Rilkis Hilla Ben-David 《Reproductive toxicology (Elmsford, N.Y.)》2006,21(4):458
Toxoplasma gondii (T. gondii) is the cause of toxoplasmosis. Primary infection in an immunocompetent person is usually asymptomatic. Serological surveys demonstrate that world-wide exposure to T. gondii is high (30% in US and 50–80% in Europe). Vertical transmission from a recently infected pregnant woman to her fetus may lead to congenital toxoplasmosis. The risk of such transmission increases as primary maternal infection occurs later in pregnancy. However, consequences for the fetus are more severe with transmission closer to conception. The timing of maternal primary infection is, therefore, critically linked to the clinical manifestations of the infection. Fetal infection may result in natural abortion. Often, no apparent symptoms are observed at birth and complications develop only later in life. The laboratory methods of assessing fetal risk of T. gondii infection are serology and direct tests.Screening programs for women at childbearing age or of the newborn, as well as education of the public regarding infection prevention, proved to be cost-effective and reduce the rate of infection.The impact of antiparasytic therapy on vertical transmission from mother to fetus is still controversial. However, specific therapy is recommended to be initiated as soon as infection is diagnosed. 相似文献
10.
W Buchinger B Leopold P Lind W Langsteger G Klima P K?ltringer O Wawschinek O Eber 《Wiener klinische Wochenschrift》1988,100(18):619-621
The zinc level in serum and whole blood was determined in a series of 121 patients, 20 suffering from overt hyperthyroidism, 34 with manifest hypothyroidism and a control group of 67 euthyroid subjects. The zinc content per deciliter of erythrocytes was calculated from the haematocrit. The hyperthyroid group revealed a highly significantly elevated serum zinc level (p less than 0.01), but a most significantly reduced zinc content in whole blood (p less than 0.001) in comparison with the euthyroid group. On the other hand, the reverse changes were observed in the hypothyroid group, i.e. a most significantly reduced serum zinc content (p less than 0.001) and a highly significantly increased zinc content in whole blood (p less than 0.01). These results suggest that the determination of zinc levels both in serum and in whole blood may be a useful additional parameter of peripheral thyroid hormone effect. 相似文献