全文获取类型
收费全文 | 3197篇 |
免费 | 157篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 36篇 |
儿科学 | 152篇 |
妇产科学 | 272篇 |
基础医学 | 303篇 |
口腔科学 | 48篇 |
临床医学 | 255篇 |
内科学 | 656篇 |
皮肤病学 | 37篇 |
神经病学 | 288篇 |
特种医学 | 81篇 |
外科学 | 496篇 |
综合类 | 13篇 |
一般理论 | 1篇 |
预防医学 | 127篇 |
眼科学 | 97篇 |
药学 | 169篇 |
中国医学 | 1篇 |
肿瘤学 | 336篇 |
出版年
2023年 | 11篇 |
2022年 | 19篇 |
2021年 | 58篇 |
2020年 | 33篇 |
2019年 | 46篇 |
2018年 | 74篇 |
2017年 | 49篇 |
2016年 | 54篇 |
2015年 | 72篇 |
2014年 | 89篇 |
2013年 | 137篇 |
2012年 | 175篇 |
2011年 | 191篇 |
2010年 | 110篇 |
2009年 | 90篇 |
2008年 | 182篇 |
2007年 | 236篇 |
2006年 | 240篇 |
2005年 | 253篇 |
2004年 | 241篇 |
2003年 | 231篇 |
2002年 | 184篇 |
2001年 | 30篇 |
2000年 | 29篇 |
1999年 | 27篇 |
1998年 | 39篇 |
1997年 | 24篇 |
1996年 | 32篇 |
1995年 | 41篇 |
1994年 | 30篇 |
1993年 | 33篇 |
1992年 | 22篇 |
1991年 | 21篇 |
1990年 | 14篇 |
1989年 | 11篇 |
1988年 | 13篇 |
1987年 | 16篇 |
1986年 | 20篇 |
1985年 | 10篇 |
1984年 | 21篇 |
1983年 | 25篇 |
1982年 | 16篇 |
1981年 | 20篇 |
1980年 | 15篇 |
1979年 | 8篇 |
1978年 | 16篇 |
1977年 | 15篇 |
1975年 | 6篇 |
1974年 | 6篇 |
1973年 | 6篇 |
排序方式: 共有3368条查询结果,搜索用时 15 毫秒
61.
62.
We compared exhaled breath condensate (EBC) and induced sputum (IS) for assessing inflammation in pulmonary diseases in patients
with obstructive lung disease (n = 20), persistent cough >6 months (n = 20), interstitial lung disease (n = 25) and controls (n = 10). EBC was collected by suspending a Teflon perfluoroalkoxy tube installed in an ice-filled container and connected to
a polypropylene test tube. IS was recovered after 20’ inhalation of 3% saline with an ultrasonic nebulizer, and 300 cells
were differentially counted in cytospin Giemsa-stained slides. H202 was measured by a method based on oxidation of phenolsulfonphthalein (phenol red) mediated by horseradish peroxidases and
H202. Pulmonary function tests were performed by conventional methods. H202 levels in EBC and % eosinophils in IS were significantly different between groups. A positive and significant correlation
was found between % eosinophils in IS and the levels of H202 in EBC for each group and for all patients combined. 相似文献
63.
Tang Y Saul A Gur M Goei S Wong E Ersoy B Snodderly DM 《Journal of neurophysiology》2007,97(5):3439-3448
Studies of visual function in behaving subjects require that stimuli be positioned reliably on the retina in the presence of eye movements. Fixational eye movements scatter stimuli about the retina, inflating estimates of receptive field dimensions, reducing estimates of peak responses, and blurring maps of receptive field subregions. Scleral search coils are frequently used to measure eye position, but their utility for correcting the effects of fixational eye movements on receptive field maps has been questioned. Using eye coils sutured to the sclera and preamplifiers configured to minimize cable artifacts, we reexamined this issue in two rhesus monkeys. During repeated fixation trials, the eye position signal was used to adjust the stimulus position, compensating for eye movements and correcting the stimulus position to place it at the desired location on the retina. Estimates of response magnitudes and receptive field characteristics in V1 and in LGN were obtained in both compensated and uncompensated conditions. Receptive fields were narrower, with steeper borders, and response amplitudes were higher when eye movement compensation was used. In sum, compensating for eye movements facilitated more precise definition of the receptive field. We also monitored horizontal vergence over long sequences of fixation trials and found the variability to be low, as expected for this precise behavior. Our results imply that eye coil signals can be highly accurate and useful for optimizing visual physiology when rigorous precautions are observed. 相似文献
64.
Katz O Gil L Lifshitz L Prutchi-Sagiv S Gassmann M Mittelman M Neumann D 《European journal of immunology》2007,37(6):1584-1593
Erythropoietin (Epo) is the main erythropoietic hormone. Recombinant human Epo (rHuEpo) is thus used in clinical practice for the treatment of anemia. Accumulating data reveals that Epo exerts pleiotropic activities. We have previously shown an anti-neoplastic activity of Epo in murine multiple myeloma (MM) models, and in MM patients. Our findings that this anti-neoplastic effect operates via CD8+ T lymphocytes led us to hypothesize that Epo possesses a wider range of immunomodulatory functions. Here we demonstrate the effect of Epo on B lymphocyte responses, focusing on three experimental models: (i) tumor-bearing mice, (5T2 MM mouse); (ii) antigen-injected healthy mice; and (iii) antigen-injected transgenic mice (tg6), overexpressing human Epo. In the MM model, despite bone marrow dysfunction, Epo-treated mice retained higher levels of endogenous polyclonal immunoglobulins, compared to their untreated controls. In both Epo-treated wild type and tg6 mice, Epo effect was manifested in the higher levels of splenocyte proliferative response induced in vitro by lipopolysaccharide. Furthermore, these mice had increased in vivo production of anti-dinitrophenyl (DNP) antibodies following immunization with DNP-keyhole limpet hemocyanin. Epo-treated mice showed an enhanced immune response also to the clinically relevant hepatitis B surface antigen. These findings suggest a potential novel use of rHuEpo as an immunomodulator. 相似文献
65.
66.
67.
Moshe Phillip MD Chantal Mathieu MD Marcus Lind PhD Eiichi Araki MD Paolo di Bartolo MD Richard Bergenstal MD Simon Heller MD Lars Hansen MD Markus Florian Scheerer PhD Fredrik Thoren PhD Niki Arya MSc John Xu PhD Nayyar Iqbal MD Paresh Dandona MD DEPICT- DEPICT- Investigators 《Diabetes, obesity & metabolism》2021,23(2):549-560
68.
69.
Yechiel Ziv M.D. Zvi Feigenberg M.D. Michael Zer M.D. Moshe Dintsman M.D. 《The American journal of gastroenterology》1987,82(11):1165-1168
The phenomenon of acute cholecystitis complicating an unrelated operation has been reported with increasing frequency, and may be preceded by a variety of operative procedures and a lack of previous biliary tract symptoms. Among eight such patients treated by us, seven developed acute cholecystitis postoperatively, and in one it was discovered during operation for bleeding duodenal ulcer. Two patients had undergone wide excision of the breast; two, highly selective vagotomy; one, nephrolithotomy; one, truncal vagotomy and gastroenterostomy; and one, left hemicolectomy and colostomy. In three patients, urgent cholecystectomy was performed, and four were treated conservatively with subsequent elective cholecystectomy. Histopathological studies revealed acute and chronic cholecystitis in all eight patients and cholelithiasis in four. One patient died in septic shock. Numerous contributing factors have been suggested, including hypovolemia and biliary stasis, as well as the presence of stones. It would appear that chronic cholecystitis or other biliary pathology, as found in our eight patients, is a major factor in the development of this manifestation. 相似文献
70.
OBJECTIVE: Azathioprine and 6-mercaptopurine interact in purine metabolism and DNA synthesis, thus their potential mutagenic effects have been of concern in the management of inflammatory bowel disease (IBD), especially in patients of childbearing age. Although several clinical studies have indicated their safety in both reproduction and pregnancy, in a recent large epidemiological study concerns were raised about their adverse effects in pregnant patients with IBD, and experimental or basic data on this subject are limited. The aim of this study was to investigate sperm production, sperm quality, and reproductive outcome following prolonged 6-MP administration to male mice. MATERIAL AND METHODS: Highly inbred Balb/c adult male mice were used. 6-MP at doses of 2, 5, and 8 mg/kg (n = 9 for each group) was given daily for 51 days and the treatment group was compared with controls. After 45 days of treatment, the mice were mated with females. Following 13 days of pregnancy, the products of conception were evaluated and live fetuses were examined for gross malformations. Sperm production and morphology were examined after 51 days of 6-MP administration. RESULTS: Treatment with 6-MP at all doses did not affect sperm morphology and sperm production in the testicular tubules, as compared with controls (70% normal sperm). However, pregnancy rates were inversely related to escalating doses of 6-MP: 55%, 41%, 28%, and 16% for control, 2, 5, and 8 mg/kg groups, respectively. Resorption rates (abortions) were 21% in the control group as compared with 45-50% in all the treatment groups, but the incidence of major congenital malformations was not increased. CONCLUSIONS: Long-term 6-MP treatment in male mice did not impair sperm production and sperm morphology. However, a significantly high rate of embryonic resorption indicated occult sperm damage. Thus, normal sperm analysis does not necessarily imply that sperm damage at genetic level did not occur. It is difficult to extrapolate from these results to the clinical use of 6-MP/azathioprine in IBD patients; however, further basic genetic testing for DNA damage and clinical follow-up are warranted. 相似文献