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   6602篇
  免费   356篇
  国内免费   49篇
耳鼻咽喉   111篇
儿科学   68篇
妇产科学   83篇
基础医学   763篇
口腔科学   202篇
临床医学   298篇
内科学   1902篇
皮肤病学   159篇
神经病学   571篇
特种医学   189篇
外科学   1355篇
综合类   20篇
预防医学   123篇
眼科学   265篇
药学   346篇
中国医学   7篇
肿瘤学   545篇
  2023年   58篇
  2022年   96篇
  2021年   149篇
  2020年   105篇
  2019年   138篇
  2018年   163篇
  2017年   135篇
  2016年   157篇
  2015年   145篇
  2014年   209篇
  2013年   232篇
  2012年   404篇
  2011年   437篇
  2010年   242篇
  2009年   192篇
  2008年   377篇
  2007年   340篇
  2006年   342篇
  2005年   360篇
  2004年   299篇
  2003年   325篇
  2002年   309篇
  2001年   169篇
  2000年   174篇
  1999年   179篇
  1998年   99篇
  1997年   67篇
  1996年   51篇
  1995年   51篇
  1994年   50篇
  1993年   35篇
  1992年   75篇
  1991年   78篇
  1990年   67篇
  1989年   66篇
  1988年   77篇
  1987年   68篇
  1986年   61篇
  1985年   71篇
  1984年   49篇
  1983年   30篇
  1982年   23篇
  1981年   21篇
  1980年   15篇
  1979年   39篇
  1978年   28篇
  1977年   27篇
  1976年   14篇
  1975年   13篇
  1974年   17篇
排序方式: 共有7007条查询结果,搜索用时 0 毫秒
11.
12.
Summary: Purpose: We wished to assess the risk of terato-genicity of zonisamide (ZNS) in humans.
Methods: Pregnant epileptic women treated with ZNS and their offspring were prospectively monitored from June 1989 to December 1994. The outcome of pregnancy and status of neonates were examined based on the same standardized protocol.
Results: Twenty-six offspring exposed to ZNS with or without other antiepileptic drugs (AEDs) were studied. Malformations were detected in 2 offspring (7·7%) exposed to ZNS polypharmacy. Anencephaly was detected in one case at 16 weeks of gestation (case 1, artificial abortion), and atrial septa1 defect was detected in another case at 37 weeks of gestation (case 2, delivery by cesarean section). Serum concentrations of ZNS during the first trimester of pregnancy were 6·1 μg/ml in case 1 and 6·3μ/ml in case 2; in both cases, the levels were below the therapeutic concentration range of ZNS.
Conclusions: Teratogenic effects of ZNS were not clearly defined from these results since malformations were detected in two polypharmacy cases but not in four monopharmacy cases. The present data do not indicate that the risk of ZNS teratogenicity is greater than that of other conventional AEDs. However, such risk cannot be neglected even at therapeutic dosages or concentrations of ZNS, especially in patients receiving polypharmacy.  相似文献   
13.
Mycobacterium bovis BCG (BCG) is a live vaccine used worldwide against tuberculosis. However, it has unfavourable side effects such as osteitis or osteomyelitis, and these sometimes lead to vertebral caries in some patients as a result of bone resorption. Osteoblasts might play a role in the bone resorption caused by BCG infection, because they are central cells in bone metabolism. Cultured osteoblast-like cell lines (MC3T3-E1) derived from C57BL mice susceptible to BCG infection cells were infected with BCG at several doses. Interestingly, internalization of BCG-enveloped phagosome-like membrane in osteoblast-like cells were observed by transmission electron microscopy (TEM). Owing to infection, the proliferation and alkaline phosphatase activity of the osteoblast-like cells were reduced in a dose-dependent manner. On the other hand, interleukin (IL)-6 production was considerably enhanced by infection. These results suggest that BCG infects osteoblasts, suppressing their proliferation and differentiation and inducing bone resorption, which may be related to osteitis/osteomyelitis and bone caries caused by BCG infection.  相似文献   
14.
We report a case of advanced gallbladder cancer in a 37-year-old man who presented in June 1993 with malignant obstructive jaundice. After percutaneous transhepatic biliary drainage and several diagnostic imaging examinations, the patient underwent laparotomy under a diagnosis of extremely advanced gallbladder cancer involving the confluence of the hepatic ducts. The tumor, however, was judged to be unresectable because of its massive spread into the liver along Glisson's sheath, and because of histologically proven peritoneal dissemination. After exploratory laparotomy, one course of anticancer chemotherapy (cisplatin, 100 mg/body IV, on day 1, and 5-fluorouracil, 1000 mg/body, on days 1–5, by continuous infusion) was administered and the completely obstructed hepatic duct was dramatically re-canalized. Four courses of chemotherapy were administered over a 16-month period until jaundice recurred. For these 16 months, the patient's quality of life was well maintained without biliary drainage. He died of increased peritoneal dissemination approximately 2 years after the first course of anticancer chemotherapy.  相似文献   
15.
16.
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   
17.
The histochemical demonstration of iron and the iron content was examined in the brain of a case of the special type of hepatocerebral encephalopathy (HCE). The patient had suffered from a liver disease since 36 years old. At 44 years old, she experienced the first attack of twilight state with flapping tremor. She had predilection for eating beans. Her personality gradually became euphoric with the recurrent episodes of unconsciousness. At 54 years old, she died of the complication of melena, renal insufficiency and pneumonia. The liver showed cirrhotic changes and iron content of liver was 0 or 1 after MacDonald's criterion scale. The histopathological findings of the brain showed the characteristic changes of HCE, which were incomplete softening and spongy state pseudolaminarilly extending in the deep layer of the cerebral cortex, the proliferation of the severely changed Alzheimer 2 type glia with or without intranuclear carmine positive substance. The deparaffinized sections, 20 mu in thickness, which were not fastened on slides were used for the histochemical study of iron, because iron deposits displaced inside of the brain tissues when the paraffin sections were fastened on slide glasses in the constant-temperature bath. The iron deposition was found in the central gyrus, superior temporal gyrus, medial and lateral occipito-temporal gyrus and middle temporal gyrus of occipital lobe. The iron accumulated in the ground substance, glia cell bodies, glia nuclei and unknown bodies in the 3-6 layers of cerebral cortex of these gyri. The iron accumulation demonstrated histochemically in other parts of the brain were group 1, 2 by Spatz, mammillary body, glia cell bodies in cerebellar white matter and pons.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
18.
19.
20.
S Shinka  T Komatsu  Y Dohi    T Amano 《Immunology》1979,37(1):83-90
The cellular basis of the mechanism of immunological tolerance to human gamma-globulin (H gamma G) induced in foetal and neonatal mice by materno-foetal or materno-neonatal transfer after a single injection of tolerogen (deaggregated H gamma G) into the mothers was investigated using a cell transfer system and assays of passive haemagglutinating antibodies and plaque-forming cells to H gamma G. The results demonstrated that B cells are mainly involved in the tolerance induced on the fourteenth day of gestation, whereas inactivation of T cells may account for the tolerance induced on the eighteenth day of gestation and in the neonatal stage. Treatment of the mothers with tolerogen and then anti-H gamma G serum reduced the tolerance induced on the fourteenth day of gestation, but did not affect that induced on the eighteenth day of gestation and in the neonatal stage. Cell transfer experiments showed that B-cell tolerance induced on the fourteenth day of gestation was prevented by passive antibody, while T-cell tolerance induced on the eighteenth day of gestation and in the neonatal stage was not affected by passive antibody. Assay of the anti-DNP antibody response after immunization with DNP10-H gamma G showed that treatment of mice with the tolerogen on the eighteenth day of gestation, but not the fourteenth day of gestation, inactivated H gamma G-reactive helper cells. The significance of these results is discussed in relation to the results of the cell transfer experiments described as above.  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