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   2786篇
  免费   167篇
  国内免费   28篇
耳鼻咽喉   14篇
儿科学   40篇
妇产科学   68篇
基础医学   356篇
口腔科学   76篇
临床医学   148篇
内科学   711篇
皮肤病学   23篇
神经病学   305篇
特种医学   84篇
外科学   585篇
综合类   11篇
预防医学   32篇
眼科学   39篇
药学   189篇
中国医学   3篇
肿瘤学   297篇
  2024年   5篇
  2023年   17篇
  2022年   26篇
  2021年   51篇
  2020年   32篇
  2019年   52篇
  2018年   51篇
  2017年   54篇
  2016年   52篇
  2015年   65篇
  2014年   71篇
  2013年   86篇
  2012年   166篇
  2011年   205篇
  2010年   119篇
  2009年   100篇
  2008年   184篇
  2007年   167篇
  2006年   177篇
  2005年   177篇
  2004年   174篇
  2003年   163篇
  2002年   159篇
  2001年   52篇
  2000年   46篇
  1999年   43篇
  1998年   46篇
  1997年   39篇
  1996年   38篇
  1995年   28篇
  1994年   22篇
  1993年   23篇
  1992年   31篇
  1991年   37篇
  1990年   29篇
  1989年   30篇
  1988年   11篇
  1987年   26篇
  1986年   24篇
  1985年   12篇
  1984年   11篇
  1983年   12篇
  1979年   5篇
  1978年   9篇
  1977年   5篇
  1976年   6篇
  1975年   6篇
  1973年   5篇
  1971年   6篇
  1966年   5篇
排序方式: 共有2981条查询结果,搜索用时 15 毫秒
1.
The development of new treatments for metabolic syndrome is urgent project for decreasing the prevalence of coronary heart disease and diabetes mellitus in the advanced countries. Peroxisome proliferator-activated receptor (PPAR)alpha and gamma agonists have shed light on the treatment of hypertriglyceridemia and type 2 diabetes mellitus, respectively. Among PPARs, analysis of the PPARdelta functions is lagging behind because specific PPARdelta agonists have not been developed. The appearance of new PPARdelta agonists is brightening the prospects for elucidating the physiological role of PPARdelta. PPARdelta is a new target for the treatment of metabolic syndrome. In particular, the fact that fatty acid oxidation and energy dissipation in skeletal muscle and adipose tissue by PPARdelta agonists lead to improved lipid profile, reduced adiposity and insulin sensitivity is a breakthrough. It seems that treatment of PPARdelta agonists operate similarly to the caloric restriction and prolonged exercise. We suggest that the physiological role of PPARdelta may be an indicator for switching from glucose metabolism to fatty acid metabolism. To receive new benefits of PPARdelta agonists against metabolic syndrome by increasing fatty acid consumption in skeletal muscle and adipose tissue, we need to unveil more details on the functions of PPARdelta itself and its agonists in the future.  相似文献   
2.
3.
We present herein the rare case of a young man who was found to have a solitary tumor in the right upper lobe of his lung by a routine chest X-ray. The tumor was removed by thoracoscopic surgery, and pathological examinations confirmed the diagnosis of a primary lymphangioma of the lung. A brief review of the available literature on this extremely rare type of benign tumor follows the case report.  相似文献   
4.
Recently, mean span of life has been prolonged, and extensive operations are performed on aged patients. However, there are cases which have a difference between their chronological and actual ages. Bone mineral content (BMC) decreases with age and the decrease in BMC might suggest deterioration of immunological competence as observed in osteoporosis. Whether BMC can be an index for evaluation of geriatric patients' actual age from the aspect of immunological competence was investigated. Subjects were 54 cases aged more than 60. Twenty-one healthy young males and females were enrolled as the control group. Quantitative CT is used for assessment of BMC. The value obtained by dividing BMC by the standard BMC of the same age and sex, was defined as BMC index. BMC indices of normal BMC group were more than 0.8 and those of decreased BMC group were less than 0.8. Some immunological markers were investigated. Lymphocyte subset OKT3+ was reduced and juvenile lymphocytes expressed by OKT6+ and OKT3+-(OKT4+ + OKT8+) increased (corrected). Increased in juvenile lymphocyte and decrease in lymphocyte blast transformation and competence of generating interleukin 2 were observed in decreased BMC group. BMC is useful as preoperative evaluation for geriatric operative cases and patients of BMC index below 0.8 need to be paid attention to postoperative infection.  相似文献   
5.
6.
7.
We report a case of granulocyte-colony stimulating factor producing gastric cancer with multiple liver metastases. A 68-year-old woman who complained of epigastralgia visited our hospital. Upper gastrointestinal endoscopic examination revealed a type-2 gastric cancer. The laboratory data at admission indicated leukocytosis (35,900/microl) and a high level of serum granulocyte-colony stimulating factor (61 pg/mg). Granulocyte-colony stimulating factor producing gastric cancer was diagnosed by immunohistochemistry of biopsy specimen. Since we detected multiple liver metastases, chemotherapy was performed. Granulocyte-colony stimulating factor-producing gastric cancer is relatively rare and we summarize previous reports.  相似文献   
8.
Abstract: In order to examine the characteristics of potential difficult-to-manage psychiatric cases, seven potential subgroups were extracted from the criminal offenders who were sent to the division of psychiatric diagnosis, Tokyo District Public Prosecutors Office for Pre-Prosecution Psychiatric Justice (PPPJ). The following criteria were used to select the potential subgroups: offenders who had experienced compulsory discharge from a mental hospital, those who had experienced Involuntary Admission to the mental hospital by the Prefectural Governor at least twice, those who had experienced admission to mental hospitals on more than 5 occasions, those who had been put on PPPJ previously for other criminal matters at least 3 times, those who had previously attempted suicide, and those who had committed homicide or arson. From the results of this study, it could be concluded that at least two types of "difficult-to-manage" psychiatric cases exist in the criminal offenders.  相似文献   
9.
The relationship between the histological grade of dedifferentiation of thyroid cancer and estrogen receptors (ER) was examined immunohistochemically. Thyroid cancers were from postmenopausal females of almost the same mean age (69-73 years old) and within the same period of time (1974–1983). ER immunoreactivity located in the nucleus of the epithelium was found in all 6 well differentiated papillary cancers, and 5 of them (83.3%) showed ER-immunoreactive (ER-IR) cells amounting to 20 or more per visual field (x 100) under a light microscope. Of the 6 cases of poorly differentiated papillary cancer, 5 (83.3%) had 1-19 ER-IR cells per visual field. ER-IR cells were negative in 5 out of 6 cases (83.3%) of anaplastic cancers. Thus, the number of ER-IR cells tended to decrease with the degree of atypism of thyroid cancer (P < 0.001).  相似文献   
10.
Background: The objective of this study was to identify the extent to which propofol alters intracellular free Ca2+ concentration ([Ca2+]i), myofilament Ca2+ sensitivity, and contraction of individual cardiomyocytes during activation of [alpha]1a adrenoreceptors and to determine the cellular mechanism of action.

Methods: Freshly isolated ventricular myocytes were obtained from adult rat hearts. Myocyte shortening and [Ca2+]i were simultaneously monitored in individual cardiomyocytes exposed to phenylephrine after treatment with chloroethylclonidine ([alpha]1b-adrenoreceptor antagonist) and BMY 7378 ([alpha]1d-adrenoreceptor antagonist). Data are reported as mean +/- SD.

Results: Phenylephrine increased myocyte shortening by 124 +/- 9% (P = 0.002), whereas peak [Ca2+]i only increased by 8 +/- 3% (P = 0.110). Inhibition of phospholipase A2 and phospholipase C attenuated the phenylephrine-induced increase in shortening by 84 +/- 11% (P = 0.004) and 15 +/- 6% (P = 0.010), respectively. Inhibition of protein kinase C (PKC) and Rho kinase attenuated the phenylephrine-induced increase in shortening by 17 +/- 8% (P = 0.010) and 74 +/- 13% (P = 0.006), respectively. In the presence of phenylephrine, propofol increased shortening by 40 +/- 6% (P = 0.002), with no concomitant increase in [Ca2+]i. PKC inhibition prevented the propofol-induced increase in shortening. Selective inhibition of PKC[alpha], PKC[delta], PKC[varepsilon], and PKC[zeta] reduced the propofol-induced increase in shortening by 12 +/- 5% (P = 0.011), 36 +/- 8% (P = 0.001), 32 +/- 9% (P = 0.007), and 19 +/- 5% (P = 0.008), respectively. Na+-H+ exchange inhibition reduced the propofol-induced increase in shortening by 56 +/- 7% (P = 0.001).  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