首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   29144篇
  免费   1526篇
  国内免费   176篇
耳鼻咽喉   302篇
儿科学   425篇
妇产科学   347篇
基础医学   3810篇
口腔科学   892篇
临床医学   1979篇
内科学   7665篇
皮肤病学   430篇
神经病学   1777篇
特种医学   1009篇
外科学   4809篇
综合类   153篇
一般理论   1篇
预防医学   925篇
眼科学   708篇
药学   1974篇
中国医学   73篇
肿瘤学   3567篇
  2023年   173篇
  2022年   386篇
  2021年   619篇
  2020年   310篇
  2019年   431篇
  2018年   596篇
  2017年   467篇
  2016年   575篇
  2015年   564篇
  2014年   713篇
  2013年   884篇
  2012年   1348篇
  2011年   1562篇
  2010年   830篇
  2009年   692篇
  2008年   1278篇
  2007年   1389篇
  2006年   1363篇
  2005年   1375篇
  2004年   1304篇
  2003年   1305篇
  2002年   1220篇
  2001年   935篇
  2000年   937篇
  1999年   893篇
  1998年   325篇
  1997年   261篇
  1996年   284篇
  1995年   218篇
  1994年   199篇
  1993年   176篇
  1992年   692篇
  1991年   628篇
  1990年   579篇
  1989年   652篇
  1988年   562篇
  1987年   515篇
  1986年   523篇
  1985年   476篇
  1984年   306篇
  1983年   239篇
  1982年   133篇
  1981年   101篇
  1980年   110篇
  1979年   220篇
  1978年   175篇
  1977年   137篇
  1974年   110篇
  1971年   119篇
  1969年   126篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
In order to clarify the appearance of monocytoid B lymphocytes (MBLs) in abscess-forming granulomatous lymphadenitis (AGL) and the relation between AGL and cat-scratch disease (CSD), 48 cases of AGL were studied histologically. MBLs were present in about 50% of AGL cases. Warthin-Starry (WS) silver stain-positive bacteria, which are the causative agent of CSD, were present in 52.4% of AGL cases with MBLs and 59.2% of AGL cases without MBLs. The appearance of MBLs in AGL was not related to various clinical features, including disease interval from initial lymphadenopathy to lymph node biopsy. Histologically, epithelioid cell clusters appeared in about 70% of MBL-positive AGL cases, but were not observed in MBL-negative AGL. Therefore, a close interaction between MBLs and epithelioid cells in AGL is suggested, and we emphasize that the histological features of some AGL cases resemble those of toxoplasmic lymphadenitis.  相似文献   
122.
A 27-year-old woman developed chickenpox postpartum. Her 2-month-old son who was breast fed also acquired chickenpox 16 days after the onset of the mother's illness. Varicella-zoster virus (VZV) DNA was detected in maternal breast milk by the polymerase chain reaction. These results suggest that transmission of VZV may occur via maternal breast milk.  相似文献   
123.
Clinical evaluation of cefmenoxime (CMX, Bestcall) was performed against infections associated with hematological, respiratory tract and other disorders. Clinical effectiveness of CMX against severe infections with hematological disorders including sepsis, pneumonia, pyelitis and so on was 74.4% for good responses and against the respiratory tract infections, 96.2% for good responses was obtained. Neither objective or subjective side effects nor extreme abnormalities in laboratory tests were observed in these patients. It can be concluded, therefore, that CMX is one of the most useful drugs against infectious diseases associated with hematological disorders, respiratory tract and other disorders.  相似文献   
124.
A case of small cell carcinoma of the prostate without a primary lesion in the lung was reported. The cancer was diagnosed after the patient complained of lumbago caused by bone metastasis. The tumor was 5.9 times 5.0 times 4.6cm. The patient was treated with 4 courses of chemotherapy using cisplatin and etoposide. The tumor diminished to 4.0 times 4.0 times 3.5 cm after completion of the 4 courses of treatment. Prostatic antigen levels were less than 1.0ng/mL during the therapy. Neuron-specific enolase levels were 35.9ng/mL at the beginning of therapy, and decreased to 7.4 ng/mL after completion of 4 courses of treatment. The patient died 3 months after the completion of treatment. This regimen had some value for inhibiting the growth of small cell carcinoma.  相似文献   
125.
This study was designed to explore the health status or quality of life (QOL) in 366 patients with rheumatoid arthritis in Japan. Physical, social, and emotional functions of the patients, namely the QOL, were measured by the modified health assessment questionnaire, the quality of well-being score, and the face scale, respectively. These functions were also evaluated by the new methods using visual analogue scales. The longer the duration of rheumatoid arthritis, the worse the QOL measures in these patients. A similar result was observed in the relationship between the stage classification of progression of rheumatoid arthritis and the QOL measures. In contrast, the traditional medical process measures, such as Lansbury activity index, sedimentation rate, and serum CRP concentration did not correlate with the duration of the disease. We conclude that the QOL measures in this study are useful for evaluation of the functional status and well-being of patients with rheumatoid arthritis. However, the clinical usefulness of these measures for evaluation of effectiveness and/or side effects of anti-rheumatic drugs still remains unknown.  相似文献   
126.
To evaluate the effect of smoking on nonrespiratory function in the lung, a dynamic PET with 13NH3 in the lung was performed in 18 normal volunteers without lung disease nor congestion (9 non-smokers, 4 exsmokers, 5 smokers). After intravenous bolus injection of 13NH3, twenty serial 5.5-second scans followed by six 30-second scans were performed. Regions of interests were assigned on the ventral, lateral and dorsal part of the right lung and time-activity curves were generated through 26 images. The activity curve demonstrated a biexponential clearance from the lung with fast and slow component. The retention fraction (RF), fractional size of the slow component, was calculated, and the half-times (t 1/2) of both components were also evaluated. A significant increase of RF and prolongation of t 1/2 of slow component were observed in smokers compared to non-smokers and exsmokers. However, no significant difference of RF nor t 1/2 of both components was observed between non-smokers and exsmokers. These results suggest that long term smoking may modify the pulmonary kinetics of 13NH3, but the change is reversible after cessation of smoking for one year or longer.  相似文献   
127.
Quality control of laboratory testings has been markedly improved. However, the importance of preanalytical quality control seems to have been poorly recognized by most medical staff members. In order to improve the present preanalytical situation, a round table discussion on sampling and transportation was held together by doctors, nurses and laboratory staff to know the present situation and to recognize the current problems. It was stressed that better communication among medical staffs and also between medical staff and patients are essential to obtain more precise data.  相似文献   
128.
B-1 virus belonging to the hantavirus group was serially passaged in the brains of newborn mice. Inactivated vaccine was prepared from the brains after inactivation with formalin and then purification by ultracentrifugation. The antigenic potency of this vaccine in vitro was determined by antibody-bound enzyme-linked immunosorbent assay (ELISA) and serial diluted vaccine bound to an aluminium hydroxide gel was inoculated into Balb/c mice to test immunogenicity. After two injections of this vaccine preparation, antibodies were detected in the mice by immunofluorescent, neutralizing and haemagglutination inhibition antibody tests. When mice immunized with this vaccine were challenged with B-1 virus and Hantaan virus (KHF-83-61BL strain), the virus titres in their lungs and spleens were significantly less than those in non-immunized mice. These results suggest that inactivated B-1 virus vaccine is effective against virus challenge by homotypic (B-1 virus) and heterotypic (Hantaan virus) viruses.  相似文献   
129.
Prostacyclin (PGI2), a potent uterine smooth muscle relaxant, is postulated to be a major prostaglandin (PG) secreted from the human myometrium. PGI2 metabolite concentrations in the maternal plasma were reported to be elevated during pregnancy, especially during labor. Recently, we developed cultured human myometrial cells from pregnant women and reported that cyclic mechanical stretching mimicking labor increased PGI2 secretion from these cells by up-regulating PGI2 synthase promoter activities. Since elevation of cervical/vaginal interleukin-1alpha (IL-1alpha) concentrations is also a characteristic feature of delivery, and IL-1alpha is a known stimulator of PG synthesis, we investigated a possible synergistic effect of cyclic mechanical stretching and IL-1alpha on PGI2 production in cultured human myometrial cells. Treatment with IL-1alpha (10 ng/ml) significantly augmented (4- to 60-fold) the secretion of PGI2, prostaglandin E2 (PGE2), prostaglandin F2alpha (PGF2alpha) and thromboxane A2 (TXA2) from cultured human myometrial cells obtained from non-pregnant and pregnant women as well as in cultured human umbilical artery and cultured human coronary artery smooth muscle cells (p < 0.05 for all comparisons). However, labor-like cyclic mechanical stretching up-regulated IL-1alpha-augmented PGI2 secretion from myometrial cells obtained from non-pregnant and pregnant women 2.1- to 2.8-fold (p < 0.05 for all comparisons), but not PGE2, PGF2alpha nor TXA2. Moreover, such an augumentation of PGI2 secretion by cyclic mechanical stretching was not observed in cultured human umbilical artery nor in cultured human coronary artery smooth muscle cells. These results suggest that cyclic mechanical stretching by labor, in concert with IL-1alpha stimulation, contributes to the increase in myometrial PGI2 secretion during delivery.  相似文献   
130.
AIM: Bone scintigraphy was performed to elucidate the effects of the Nuss procedure for pectus excavatum on the bony thorax. METHODS: Eight boys and 6 girls (5 - 24 years of age) underwent bone scintigraphy, using (99m)Tc-HMDP. Eleven patients were studied 5 to 21 days after the Nuss procedure; 6 were studied 20 to 24 months after the operation before bar removal. Three of 14 were studied twice after the Nuss procedure and before bar removal. RESULTS: In the early postoperative phase, RI accumulation was found at the sternum and ribs in only 1 of 6 patients under 9 years of age, whereas in all 5 older patients, RI had accumulated at the sternum. Scintigrams before bar removal revealed, regardless of age, hot spots at the lateral ribs in contact with the bar and at the costochondral junctions where the bar passed through the intercostal spaces. Furthermore, chest roentgenograms showed the deformed lateral ribs in contact with the bar. CONCLUSIONS: The Nuss procedure creates minute fractures at the sternum and the ribs, especially in older patients. The bar deforms the ribs and restrains the growth of the thorax. Furthermore, it constantly rubs against the ribs and can therefore cause late complications. Bone scintigraphy may determine the appropriate timing for bar removal.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号