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   2213篇
  免费   116篇
  国内免费   52篇
耳鼻咽喉   12篇
儿科学   114篇
妇产科学   46篇
基础医学   278篇
口腔科学   77篇
临床医学   199篇
内科学   573篇
皮肤病学   59篇
神经病学   146篇
特种医学   161篇
外科学   162篇
综合类   31篇
一般理论   1篇
预防医学   186篇
眼科学   33篇
药学   164篇
中国医学   12篇
肿瘤学   127篇
  2023年   13篇
  2022年   32篇
  2021年   53篇
  2020年   22篇
  2019年   50篇
  2018年   45篇
  2017年   43篇
  2016年   53篇
  2015年   59篇
  2014年   83篇
  2013年   95篇
  2012年   120篇
  2011年   157篇
  2010年   90篇
  2009年   66篇
  2008年   84篇
  2007年   139篇
  2006年   87篇
  2005年   74篇
  2004年   56篇
  2003年   54篇
  2002年   69篇
  2001年   49篇
  2000年   50篇
  1999年   43篇
  1998年   57篇
  1997年   57篇
  1996年   60篇
  1995年   35篇
  1994年   36篇
  1993年   30篇
  1992年   28篇
  1991年   25篇
  1990年   25篇
  1989年   43篇
  1988年   41篇
  1987年   35篇
  1986年   32篇
  1985年   23篇
  1984年   20篇
  1983年   16篇
  1982年   21篇
  1981年   16篇
  1980年   15篇
  1979年   9篇
  1978年   11篇
  1977年   11篇
  1976年   14篇
  1975年   14篇
  1971年   6篇
排序方式: 共有2381条查询结果,搜索用时 15 毫秒
91.
92.
Yoo E‐H, Woo H, Ki C‐S, Lee HJ, Kim D‐K, Kang I‐S, Park P, Sung K, Lee CS, Chung T‐Y, Moon JR, Han H, Lee S‐T, Kim J‐W. Clinical and genetic analysis of Korean patients with Marfan syndrome: possible ethnic differences in clinical manifestation. Marfan syndrome (MFS) is an autosomal dominant disorder of the fibrous connective tissue caused by mutations in the fibrillin‐1 (FBN1) gene. Although clinical and genetic analyses have been performed in various populations, there have been few studies in Korea. The aim of this study was to investigate the clinical characteristics and genetic background of Korean patients with MFS. In 39 Korean patients with MFS who met the Ghent criteria, the most common clinical finding was aortic dilatation and/or dissection (94.9%), whereas only 35.9% of patients had ectopia lentis. The majority of MFS patients had fewer than four of the skeletal findings required to fulfill the major skeletal Ghent criterion for MFS. Only 21% of Korean patients had major skeletal abnormalities and most cases showed only minor skeletal involvement. FBN1 gene mutations were detected in 35 out of 39 patients (89.7%), which is similar to rates presented in the previous reports. These results suggest that some clinical features in Korean patients with MFS differed from those reported in Western MFS patients.  相似文献   
93.
Concern has been raised regarding the response to vaccination in solid organ transplant recipients (SOTR) undergoing immunosuppressant regimens and the possibility of rejection related to the immune response associated with pandemic influenza H1N1–2009 vaccination. The goal of this study was to assess the immunogenicity, efficacy and safety of the pandemic vaccine in SOTR. We performed a multicenter prospective study in SOTR receiving the pandemic vaccine. Immunological response was determined in serum 5 weeks after vaccination by microneutralization assays, and immunoglobulins were measured by ELISA. Three hundred and forty‐six SOTR were included. Preexisting seroprotection was detected in 13.6% of cases and rates of seroconversion and seroprotection after vaccination were 73.1% and 82.9%, respectively. Patients with baseline antibody titers had better geometric mean titers (GMT)‐post after pandemic vaccination (339.4 vs. 121.4, p < 0.001). Younger age, liver disease and m‐TOR inhibitor therapy were independently associated with lower seroprotection and GMT‐post. There were no major adverse effects or rejection episodes. Pandemic vaccine was safe in SOTR and elicited an adequate response, although lower than in healthy individuals. This is the first study describing a decreased response after vaccination in patients receiving mTOR inhibitors who presented lower seroprotection rates and lower GMT‐post.  相似文献   
94.
We identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) 10 species and 5 subspecies of Staphylococcus among 139 clinical isolates and compared it with conventional tests. All isolates showed species-specific whole-cell protein profiles, even atypical strains, with up to 60% and at least 73.5% of interspecies and intraspecies similarity, respectively. Except for 5 isolates that presented biochemical profiles of Staphylococcus hominis subsp. hominis, but were identified as S. hominis subsp. novobiosepticus by SDS-PAGE, there was 100% accordance between the methods used. Comparison with the partial 16S-rDNA sequences confirmed by SDS-PAGE showed the high accuracy of this method to identify staphylococci subspecies and species.  相似文献   
95.
In migraine, headache severity varies with age. As a consequence, the effectiveness of medication may also depend on a patient's age. The purpose of this study was to assess the combined effect of age and drug treatment on headache characteristics. Using data from clinical trials of sumatriptan in adolescents and adults, we show how the interaction between age and drug exposure can be parameterised as a covariate on a Markov model that describes the decline of headache severity over three clinically defined stages (no relief, relief and pain-free status). The model explains important clinical observations: (i) the rates at which the pain relief and pain-free status were attained were found to be inversely related to age; (ii) in placebo-treated patients, the mean transit time from 'no relief' to 'relief' is 3 h for young adolescents and increases to 6 h for patients aged ≥ 30 years; and (iii) sumatriptan reduces the transit time to 2 h, irrespective of age. These findings indicate that the therapeutic gain over placebo increases with age. Prospective studies of antimigraine drugs should take this relationship into account when extrapolating efficacy data from adults to adolescents.  相似文献   
96.
Rats segregated according to low (LA) or high (HA) anxiety levels have been used as an important tool in the study of fear and anxiety. Since the efficacy of an anxiolytic compound is a function of the animal's basal anxiety level, it is possible that chronic treatment with a benzodiazepine (Bzp) affects LA and HA animals differently. Based on these assumptions, this study aimed to provide some additional information on the influence of acute, chronic (18 days) and withdrawal effects (48 h) from diazepam (10 mg/kg), in rats with LA or HA levels, on startle response amplitude. For this purpose, the elevated plus-maze (EPM) test was used. In addition, the role of glutamate receptors of the central nucleus of the inferior colliculus (cIC), the most important mesencephalic tectum integrative structure of the auditory pathways and a brain region that is linked to the processing of auditory information of aversive nature, was also evaluated. Our results showed that, contrary to the results obtained in LA rats, long-term treatment with diazepam promoted anxiolytic and aversive effects in HA animals that were tested under chronic effects or withdrawal from this drug, respectively. In addition, since Bzp withdrawal may function as an unconditioned stressor, the negative affective states observed in HA rats could be a by-product of GABA-glutamate imbalance in brain systems that modulate unconditioned fear and anxiety behaviors, since the blockade of alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) and N-methyl-d-aspartate (NMDA) glutamate receptors in the cIC clearly reduced the aversion promoted by diazepam withdrawal.  相似文献   
97.
For individuals meeting Bethesda criteria for hereditary nonpolyposis colorectal cancer syndrome, the microsatellite instability (MSI) test is recommended as a screening evaluation before proceeding to genetic testing. The MSI test is new to the medical setting, but will be increasingly used to screen patients at high risk for hereditary nonpolyposis colorectal cancer. The main goals of this study were to examine knowledge about and exposure to the MSI test among individuals considering the test, to evaluate perceived benefits and barriers to undergoing the MSI test, and to identify the demographic, medical, and psychosocial correlates of the perceived benefits and barriers to undergoing the test. One hundred and twenty-five patients completed a survey after being offered the test, but prior to making the decision whether to pursue MSI testing. Results indicated low levels of knowledge about and previous exposure to the MSI test. Participants held positive attitudes about the potential benefits of the test and perceived few barriers to undergoing the test. Motivations were similar to those cited by individuals considering other genetic tests. Participants with nonmetastatic disease, with lower perceived risk for cancer recurrence, and who reported more self-efficacy endorsed more benefits from the test. Higher levels of cancer-specific psychological distress were associated with more perceived barriers to having the test. These findings suggest that individuals considering the MSI test know very little about it but hold positive attitudes about the test's utility. More distressed patients, patients who perceive themselves at higher risk for cancer recurrence, and patients with metastatic disease might be less motivated to have the MSI test.  相似文献   
98.
99.
Background  Endoscopic resection is an adequate treatment for subgroups of patients with early gastric cancer. Endoscopic submucosal dissection (ESD) represents a recent advance and leads to good results when adequately indicated. There is great experience with this technique in Japan and it is gaining acceptance among Western endoscopists. We present the first gastric ESD series performed in Brazil. Methods  Patients with well-differentiated adenocarcinomas macroscopically classified as early cancer, less than 30 mm with no ulcer or scar, were included. ESD was performed with an insulated-tip knife and electrosurgical unit with endocut mode. Clinicopathological aspects and morbidity were evaluated. The study was approved by the local ethics committee and informed consent was obtained from all participant subjects. Results  From October 2005 to July 2007, 160 patients received surgical treatment for gastric cancer; 44 patients (27.5%) had early gastric cancer. In this latter group, 15 procedures (ESD) were performed in 12 patients. The mean size of the lesions was 16.8 mm. Almost half of the lesions were located in the proximal third of the stomach and the mean elapsed time for the procedure was 140 min. In 80% of the cases resection was en bloc and 80% of the resections were considered curative. We had three perforations, which were managed clinically, and no bleeding. Conclusion  When adequately indicated, ESD is a safe and feasible technique.  相似文献   
100.
Objective: The guiding criteria are considered the backbone of Chinese medicine. They have previously been described as functional features (symptoms) leading to the overall assessment of human functions on the basis of a regulatory (cybernetic) model referring to the I Ging. Methods: The Heidelberg model can explain symptoms such as created by "heat" on a rational physiological level. Results & Conclusion: The overall of physiological symptoms are shown as a schematic draft. The basis of "heat" is considered to be a general increase of microcirculation in the periphery. This leads to a couple of local pathophysiological consequences and sensations like 1) red tongue (the tongue is considered an embryological somatotopic system). 2) Sensation of warmth (by increase of capillary flow). 3) pre-inflammatory state, leading to pain modalities like "worse if pressed", as inflammations tend to be increasingly painful under pressure; 4) reddish skin, the mechanisms by which this is induced may include the release of substance P, therefore accompanied by burning sensation. Systemic pathophysiological consequences may include. Relative lack of fluid in the larger vessels, as fluid supplies peripheral capillary flow. This may lead to water saving mechanisms like thirst, dry mucosa with do, mouth, dry nose, dry lips, dry skin, and also dry stool, yellow and sparse urine.  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