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   736篇
  免费   48篇
  国内免费   14篇
耳鼻咽喉   12篇
儿科学   18篇
妇产科学   7篇
基础医学   82篇
口腔科学   6篇
临床医学   61篇
内科学   240篇
皮肤病学   10篇
神经病学   33篇
特种医学   42篇
外科学   113篇
综合类   13篇
一般理论   1篇
预防医学   55篇
眼科学   22篇
药学   52篇
中国医学   2篇
肿瘤学   29篇
  2023年   8篇
  2022年   9篇
  2021年   37篇
  2020年   21篇
  2019年   29篇
  2018年   29篇
  2017年   20篇
  2016年   17篇
  2015年   26篇
  2014年   51篇
  2013年   38篇
  2012年   73篇
  2011年   72篇
  2010年   42篇
  2009年   41篇
  2008年   58篇
  2007年   56篇
  2006年   33篇
  2005年   33篇
  2004年   24篇
  2003年   27篇
  2002年   27篇
  2001年   4篇
  2000年   2篇
  1999年   5篇
  1998年   3篇
  1996年   1篇
  1995年   2篇
  1994年   1篇
  1993年   2篇
  1992年   2篇
  1987年   2篇
  1984年   1篇
  1979年   2篇
排序方式: 共有798条查询结果,搜索用时 223 毫秒
1.
From October 1987 through March 1991, 58 patients with postoperative joint stiffness underwent arthroscopic fibroarthrolysis. Forty-six knees in 46 patients were followed. The indication for arthroscopic management was decreased range of motion after surgery. Eighty-seven percent had been treated by arthrotomy. Thirteen percent had been managed by arthroscopic surgery. The indication for primary surgery was a torn anterior cruciate ligament in 74%. The mean interval between arthroscopic fibroarthrolysis and follow-up was 22.1 months. The average age was 32.7 years. A modified Blauth and Jäger score was used for classification of fibroarthrosis: grade I (mild 17.4%), grade II (moderate 63%), grade III (severe 15.2%), and grade IV (bad 4.3%). The gain in range of motion was evaluated by the Cauchoix index: the results were excellent in 54.5%, good in 21.7%, and fair and poor in 23.8%. Pain was evaluated according to a modification of the Lysholm score: 80.4% of the patients experienced a reduction in pain. The sports activity level in the Tegner activity scale increased from 2.3 to 4.8. Patient satisfaction was excellent or good in 56.5% (n = 26), fair in 39.1% (n = 18), and poor in 4.3% (n = 2). On the basis of our retrospective study, we feel that arthroscopic fibroarthrolysis is of benefit to the patients with postoperative joint stiffness even after a prolonged period.  相似文献   
2.
In the study of asthma, a vital role is played by mouse models, because knockout or transgenic methods can be used to alter disease pathways and identify therapeutic targets that affect lung function. Assessment of lung function in rodents by available methods is insensitive because these techniques lack regional specificity. A more sensitive method for evaluating lung function in human asthma patients uses hyperpolarized (HP) (3)He MRI before and after bronchoconstriction induced by methacholine (MCh). We now report the ability to perform such (3)He imaging of MCh response in mice, where voxels must be approximately 3000 times smaller than in humans and (3)He diffusion becomes an impediment to resolving the airways. We show three-dimensional (3D) images that reveal airway structure down to the fifth branching and visualize ventilation at a resolution of 125 x 125 x 1000 microm(3). Images of ovalbumin (OVA)-sensitized mice acquired after MCh show both airway closure and ventilation loss. To also observe the MCh response in naive mice, we developed a non-slice-selective 2D protocol with 187 x 187 microm(2) resolution that was fast enough to record the MCh response and recovery with 12-s temporal resolution. The extension of (3)He MRI to mouse models should make it a valuable translational tool in asthma research.  相似文献   
3.
Intestinal metaplasia is a key event in multistep gastric carcinogenesis. CDX2, a master regulator of intestinal phenotype, was shown to play a tumor-suppressive role in colon cancer. However, it was reported to be expressed in nearly all gastric intestinal metaplasia and many gastric cancers. As CDX2 is differentially expressed in normal stomach and intestine, we sought to relate the CDX2 expression to gastrointestinal differentiation along gastric carcinogenesis. The expression of CDX2 protein in gastric intestinal metaplasia, dysplasia and cancer was examined and related to their gastrointestinal differentiation. CDX2 expression was significantly decreased in incomplete intestinal metaplasia, which expresses both gastric mucins (MUC5AC and MUC6) and intestinal mucin (MUC2), compared with complete intestinal metaplasia, which expresses intestinal mucin (MUC2) only. Although incomplete intestinal metaplasia morphologically resembles colon, its CDX2 expression was apparently lower than that in the normal colon. Moreover, CDX2 expression was progressively reduced in gastric dysplasia and cancer. The CDX2 expression in gastric cancer was also inversely correlated with the expression of gastric mucins. As incomplete intestinal metaplasia is associated with higher risk of gastric cancer, its lower CDX2 expression compared with that in complete intestinal metaplasia and normal colon epithelium resolved the current contradiction between the tumor-suppressive role of CDX2 in the colon and the high prevalence of CDX2 in intestinal metaplasia. Further decrease of CDX2 expression in gastric dysplasia and cancer suggests that CDX2 plays a similar anticarcinogenic role in intestinal metaplasia as it does in colon. Intestinal metaplasia or dysplasia with low expression of CDX2 may serve as predictive markers for gastric cancer.  相似文献   
4.
Objective: Serum prolactin is influenced by antipsychotic use but its relationships with psychopathology and general functioning are not clear. This study aimed to assess these relationships.Design: Serum prolactin levels were measured in patients with schizophrenia before being treated with antipsychotics and at various follow-up points.Setting: The study was conducted in a nongovernmental psychiatric treatment center in Mumbai, India.Participants: The participants included 30 male and 30 female drug-na?ve patients with schizophrenia and 31 control participants.Measurements: The severity of psychopathology at baseline, three weeks, six weeks, and five years following treatment was assessed using a modified Brief Psychiatric Rating Scale. The Global Assessment of Functioning questionnaire was used at baseline and five years follow up.Results: Contrary to our hypotheses, prolactin levels in male but not female patients at baseline were twice those of control volunteers. Correlations between prolactin, Brief Psychiatric Rating Scale, and Global Assessment of Functioning measurements were not significant for any time point up to six weeks, but were only significant at the five-year follow-up appointments, indicating that those patients with higher levels of serum prolactin had a better outcome at five years.Conclusion: Baseline serum prolactin levels in drug-naive patients with schizophrenia may be used for long-term prognosis, but are not reliable indicators of psychopathology and prognosis in the short term. Future research is needed to conclude with confidence whether or not prolactin can be used as a biomarker of psychopathological and overall functioning in schizophrenia.  相似文献   
5.
6.
7.
BackgroundSelf-retaining brain retractors are commonly used during intracranial surgery, and they are indispensable during microneurosurgery. There is a common severe complication due to the use of self-held retractors, that is, formation of a hemorrhagic infarct area in the brain region exposed to traction. All the more, present retractor systems are fixed and rigid and obstruct surgeons during surgery. Sometimes these retractors create glare in the microscope that distracts the surgeon. We hereby propose a simple and easy method of retraction of brain especially the temporal lobe using the transsylvian approach and vermis using the transvermian approach.MethodsThis is retrospective analysis of 47 patients in 4 years in which we have used our stitch retractor. We have analyzed their outcome, postoperative scan, and ease of performing surgery.ResultsIn 47 patients, there was only 1 postoperative contusion, and the longest period it was kept for is 6 hours. The other advantage was that it does not obstruct in any way while doing dissections and surgery. There was no glare while operating under a microscope.ConclusionWe hereby propose a simple and easy method of retraction of brain especially the temporal lobe using the transsylvian approach and vermis using the transvermian approach. It is minimally traumatic, reducing insult to the brain. It allows the surgeon to dissect without any obstruction and glare in the way. The biggest advantage of the present stitch retractor is that it is very cheap and simple to use.  相似文献   
8.
9.
Telomere length (TL) has been associated with aging and mortality, but individual differences are also influenced by genetic factors, with previous studies reporting heritability estimates ranging from 34 to 82%. Here we investigate the heritability, mode of inheritance and the influence of parental age at birth on TL in six large, independent cohort studies with a total of 19 713 participants. The meta-analysis estimate of TL heritability was 0.70 (95% CI 0.64–0.76) and is based on a pattern of results that is highly similar for twins and other family members. We observed a stronger mother–offspring (r=0.42; P-value=3.60 × 10−61) than father–offspring correlation (r=0.33; P-value=7.01 × 10−5), and a significant positive association with paternal age at offspring birth (β=0.005; P-value=7.01 × 10−5). Interestingly, a significant and quite substantial correlation in TL between spouses (r=0.25; P-value=2.82 × 10−30) was seen, which appeared stronger in older spouse pairs (mean age ≥55 years; r=0.31; P-value=4.27 × 10−23) than in younger pairs (mean age<55 years; r=0.20; P-value=3.24 × 10−10). In summary, we find a high and very consistent heritability estimate for TL, evidence for a maternal inheritance component and a positive association with paternal age.  相似文献   
10.

Purpose

Conjoined twins are a rare complication of 9 monozygotic twins and are associated with high perinatal mortality. Pygopagus are one of the rare types of conjoined twins with only a handful of cases reported in the literature.

Case summary

We present the case of one-and-half month-old male pygopagus conjoined twins, who were joined together dorsally in lower lumbar and sacral region and had spina bifida and shared a single thecal sac with combined weight of 6.14 kg. Spinal cord was separated at the level of the conus followed by duraplasty. They had uneventful recovery with normal 15 months follow-up.

Conclusion

Separation of conjoined twins is recommended in where this is feasible with the anticipated survival of both or one infant.
  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