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   1841篇
  免费   150篇
  国内免费   14篇
耳鼻咽喉   4篇
儿科学   40篇
妇产科学   19篇
基础医学   177篇
口腔科学   107篇
临床医学   242篇
内科学   353篇
皮肤病学   12篇
神经病学   120篇
特种医学   214篇
外科学   165篇
综合类   106篇
预防医学   224篇
眼科学   15篇
药学   135篇
  1篇
中国医学   2篇
肿瘤学   69篇
  2022年   11篇
  2021年   27篇
  2020年   15篇
  2019年   26篇
  2018年   43篇
  2017年   18篇
  2016年   24篇
  2015年   29篇
  2014年   35篇
  2013年   77篇
  2012年   98篇
  2011年   78篇
  2010年   63篇
  2009年   56篇
  2008年   75篇
  2007年   97篇
  2006年   78篇
  2005年   68篇
  2004年   69篇
  2003年   59篇
  2002年   55篇
  2001年   50篇
  2000年   44篇
  1999年   51篇
  1998年   35篇
  1997年   31篇
  1996年   29篇
  1995年   29篇
  1994年   40篇
  1993年   43篇
  1992年   42篇
  1991年   29篇
  1990年   39篇
  1989年   40篇
  1988年   36篇
  1987年   58篇
  1986年   39篇
  1985年   40篇
  1984年   20篇
  1983年   21篇
  1982年   18篇
  1981年   21篇
  1980年   15篇
  1978年   12篇
  1977年   11篇
  1976年   10篇
  1974年   14篇
  1971年   9篇
  1969年   9篇
  1968年   9篇
排序方式: 共有2005条查询结果,搜索用时 0 毫秒
51.
Gjerset  GF; Martin  PJ; Counts  RB; Fast  LD; Hansen  JA 《Blood》1984,64(3):715-720
We evaluated 37 patients with moderate or severe hemophilia A and six patients with severe factor IX deficiency for clinical or laboratory evidence of immune abnormalities. Patients were assigned to one of four groups according to the type of clotting factor replacement. Twenty patients had received only cryoprecipitate during the two years preceding the evaluation (group I); 11 additional patients were treated predominantly with cryoprecipitate but had also received up to nine bottles of factor VIII concentrate (group II); six patients received factor VIII concentrate (group III); six patients received factor IX concentrate (group IV). There was no clinical or laboratory evidence of immunodeficiency among the 43 patients. The mean absolute number of Th cells was normal in all patient groups, but the mean absolute number of Ts cells was increased compared with controls, both in patients treated with cryoprecipitate and in patients treated with factor VIII or factor IX concentrate. There was no correlation between the Th/Ts ratio and patient age, alanine aminotransferase level, hepatitis serology, in vitro lymphocyte function, or amount of clotting factor administered. Our observations demonstrate that the volunteer or commercial origin of clotting factor replacement cannot fully explain the alterations in lymphocyte subset distribution previously described in patients with hemophilia A.  相似文献   
52.
53.
54.
55.
Oral Diseases (2012) 18 , 353–359 Objective: To explore the possible relationship between the osteoporotic condition and the severity of periodontitis in women aged 45–70 years. Materials and Methods: Ninety women with generalized chronic periodontitis, aged 45–70 years, were studied. Areal bone mineral density (BMDa) was assessed using standardized dual energy X‐ray absorptiometry (normal: T‐score ≥ ?1, osteopenic: ?2.5 ≤ T‐score T‐score < ?2.5). Gingival index (GI), bleeding on probing, clinical attachment loss (CAL), probing pocket depth and gingival recession (GR) were recorded. Periodontitis severity was represented by CAL. Menopausal condition and smoking were documented. Results: Mean GI, bleeding on probing, CAL and GR were significantly greater for osteoporotic women than women with normal BMDa (P = 0.002, P = 0.01, P = 0.04, respectively). Osteopenic women and women with normal BMDa significantly differed in mean GI (P = 0.02). The associations found between osteoporotic women and women with normal BMDa and the associations found between osteopenic women and women with normal BMDa existed even after adjusting for smoking and menopausal status. Conclusion: Subjects with osteoporosis (OPR) presented with greater CAL than the subjects with normal BMDa, which suggests a greater severity of periodontitis. Subjects with OPR had greater GR than the subjects with normal BMDa. Subjects with osteopenia and subjects with normal BMDa did not differ in CAL, which might suggest that the early diagnosis of reduced BMDa, prior to the establishment of a significant negative impact on the periodontal tissues, might be important. Smoking and menopausal status did not alter these associations.  相似文献   
56.
B cells may play a pivotal role in the pathophysiology of DM, and reports have claimed that targeting B cells is a viable treatment option in patients with dermatomyositis. A 20-year-old girl presented in October 2007, with few weeks’ history of proximal muscle weakness. Gottron’s papules were noted on her knuckles. She had normal inflammatory markers and negative autoantibody screen. Her CPK was 7,000 U/L (normal range 0–170) with an LDH of 1,300 U/L (normal range 266–500). EMG and muscle biopsy was consistent with active myositis. She had normal pulmonary function tests. HRCT showed no interstitial lung disease. She was started with 60 mg glucocorticoids (1 mg/kg), with a good clinical response. However, any attempt to taper down the steroid dose led to recurrence of her symptoms. The options of available immunosuppressive therapies, including the experimental usage of rituximab, were discussed with her; averse to long-term systemic treatments, she opted to try a course of rituximab. She had rituximab 1,000 mg on days 0 and 14, and her glucocorticoids were tapered in next few weeks. Now, 24 months since her rituximab infusions, she remains in complete clinical and biochemical remission and is na?ve to other immunosuppressive agents apart from glucocorticoids and rituximab. Depleting peripheral B cells with rituximab (one course) in our patient has led not only to complete resolution of muscle and skin disease (induction) but also remains off all immunosuppressives including glucocorticoids.  相似文献   
57.
58.
59.

Background

Previous work from our group demonstrated improved memory function in bariatric surgery patients at 12 weeks postoperatively relative to controls. However, no study has examined longer-term changes in cognitive functioning following bariatric surgery.

Methods

A total of 137 individuals (95 bariatric surgery patients and 42 obese controls) were followed prospectively to determine whether postsurgery cognitive improvements persist. Potential mechanisms of change were also examined. Bariatric surgery participants completed self-report measurements and a computerized cognitive test battery prior to surgery and at 12-week and 12-month follow-up; obese controls completed measures at equivalent time points.

Results

Bariatric surgery patients exhibited cognitive deficits relative to well-established standardized normative data prior to surgery, and obese controls demonstrated similar deficits. Analyses of longitudinal change indicated an interactive effect on memory indices, with bariatric surgery patients demonstrating better performance postoperatively than obese controls.

Conclusions

While memory performance was improved 12 months postbariatric surgery, the mechanisms underlying these improvements were unclear and did not appear attributable to obvious postsurgical changes, such as reductions in body mass index or comorbid medical conditions. Future studies employing neuroimaging, metabolic biomarkers, and more precise physiological measurements are needed to determine the mechanisms underlying memory improvements following bariatric surgery.  相似文献   
60.
BackgroundPrior studies have reported that students with overweight and obesity have impairments in performance IQ and executive function and worse school functioning in comparison with peers of normal weight. The present study assessed school and cognitive functioning in a sample of adolescents with severe obesity being evaluated for laparoscopic adjustable gastric banding.MethodsEligible candidates for bariatric surgery were referred for psychiatric evaluation, which included a semistructured clinical interview measuring school functioning and the vocabulary and matrix reasoning subtests of the Wechsler Abbreviated Scale of Intelligence (WASI).ResultsSelf-reported school problems were common, with 55.5% of adolescents failing a grade or subject, 38.7% attending summer school, and 17.8% failing a citywide examination. A significant relationship was observed between body mass index, estimated WASI IQ (r = ?.250; P = .005), and the vocabulary subtest (r = ?.241; P = .006), but not matrix reasoning (r = ?.126; P = NS).ConclusionEven among a sample of adolescents with severe obesity, increased body mass index was associated with lower WASI IQ and vocabulary subtest scores. Increasing awareness of potential cognitive and school problems in bariatric candidates among teachers, school counselors, and other mental health providers is an important first step to improving academic support and educational systems deficiencies for students with overweight and obesity.  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