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:      
  示例: 沙坡头地区,人工植被区,变化  检索词用空格隔开表示必须包含全部检索词,用“,”隔开表示只需满足任一检索词即可!
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   3064篇
  免费   85篇
  国内免费   6篇
耳鼻咽喉   37篇
儿科学   305篇
妇产科学   27篇
基础医学   265篇
口腔科学   59篇
临床医学   184篇
内科学   748篇
皮肤病学   60篇
神经病学   139篇
特种医学   89篇
外科学   580篇
综合类   100篇
一般理论   1篇
预防医学   91篇
眼科学   81篇
药学   146篇
中国医学   17篇
肿瘤学   226篇
  2023年   18篇
  2022年   42篇
  2021年   101篇
  2020年   57篇
  2019年   55篇
  2018年   77篇
  2017年   72篇
  2016年   68篇
  2015年   87篇
  2014年   119篇
  2013年   191篇
  2012年   181篇
  2011年   161篇
  2010年   97篇
  2009年   118篇
  2008年   201篇
  2007年   113篇
  2006年   114篇
  2005年   127篇
  2004年   114篇
  2003年   91篇
  2002年   71篇
  2001年   83篇
  2000年   84篇
  1999年   63篇
  1998年   33篇
  1997年   25篇
  1996年   17篇
  1995年   10篇
  1994年   15篇
  1993年   22篇
  1992年   41篇
  1991年   49篇
  1990年   38篇
  1989年   51篇
  1988年   41篇
  1987年   23篇
  1986年   39篇
  1985年   29篇
  1984年   22篇
  1983年   13篇
  1981年   17篇
  1979年   21篇
  1978年   9篇
  1976年   12篇
  1975年   12篇
  1973年   12篇
  1971年   9篇
  1970年   10篇
  1969年   18篇
排序方式: 共有3155条查询结果,搜索用时 15 毫秒
31.
Introduction: We assessed cardiac function (CF) in celiac disease (CD) patients and the effect of gluten-free diet (GFD) on CF.

Methods: Prospective evaluation of CF using conventional and tissue doppler echocardiography in 50 CD patients (age 4.2?±?1.1 years) at diagnosis and after a year of GFD (group 1), 100 CD children (group 2; 47 compliant and 53 non-compliant) in follow-up and 25 healthy controls.

Results: Untreated CD (n?=?50) children had larger left ventricle end diastolic dimension (35.33?±?0.87 vs. 32.90?±?0.91 mm; p?=?.04), reduced (<55%) left ventricular ejection fraction (20% vs. 0%; p?=?.01) and a higher (>0.6) myocardial performance index (MPI, 66% vs. 0%; p ≤ .01) as compared to controls. Re-evaluation after one year with good dietary compliance showed changes in isovolumic relaxation time (72.5?±?4.2 vs. 50.62?±?2.69; p?=?.0001) and deceleration time (121.05?±?10.1 vs. 99.87?±?8.5; p?=?.02), reflecting improved cardiac diastolic function. GFD compliant patients had lower MPI than non-compliant (0.60?±?.03 vs. 0.66?±?.08; p?=?.04), reflecting improvement in load-independent echocardiographic parameters.

Conclusions: Subclinical cardiac dysfunction is common in CD children at diagnosis. Improvement

in echocardiographic parameters occurs with GFD and non-compliant children continue to have

persistent cardiac dysfunction.  相似文献   
32.
The search for a perfect tumour marker, which would be able to distinguish benign from malignant enlargement of prostate accurately, is still not complete. Total Prostate Specific Antigen (TPSA), a good test, has it's own inadequacies but Free Prostate Specific Antigen (FPSA) to TPSA ratio is emerging as a better adjuvant to it. This prospective study was done to verify the utility of FPSA to TPSA ratio in diagnosis of malignancy of prostate and its relationship to Gleason grading (indicating the aggressiveness) of adenocarcinoma of prostate. 100 patients with urinary symptoms, who were above fifty years of age and had prostatic enlargement, formed the study group. TPSA and FPSA were assayed by ELISA method and FPSA to TPSA ratio was calculated. Prostatic biopsy of all the cases was obtained and diagnostic histopathology and Gleason grading (in cases where adenocarcinoma was diagnosed) was done. Sensitivity, specificity, predictive value of positive test and predictive value of negative test for TPSA and FPSA to TPSA ratio were calculated. They were found to be 100%, 76.7%, 74.1% and 100% for TPSA and 82%, 100%, 100%, 89% for FPSA/TPSA ratio. Thus making it very obvious that FPSA to TPSA ratio is an excellent adjuvant to TPSA for diagnosis of malignancy of prostate increasing the specificity and predictive value for positive test. An inverse correlation (correlation coefficient = -0.95) was also found between PSA ratio and aggressiveness of prostate cancer, pointing towards its capability to predict the histological (Gleason) grade of the tumour.  相似文献   
33.
    
Patients with indolent non‐Hodgkin lymphoma (NHL) have multiple treatment options yet there is no consensus as to the best initial therapy. Lenalidomide, an immunomodulatory agent, has single agent activity in relapsed lymphoma. This trial was conducted to assess feasibility, efficacy, and safety of adding lenalidomide to rituximab, cyclophosphamide, and dexamethasone (LR‐CD) in untreated indolent NHL patients requiring therapy. This was a single institution phase II trial. Treatment consisted of IV rituximab 375 mg/m2 day 1; oral lenalidomide 20 mg days 1–21; cyclophosphamide 250 mg/m2 days 1, 8, and 15; and dexamethasone 40 mg days 1, 8, 15, and 22 of a 28‐day cycle. Treatment continued 2 cycles beyond best response for a maximum of 12 cycles without rituximab maintenance. Thirty‐three patients were treated. Median age was 68 (43–83 years). 39% had stage IV disease. Histologic subtypes included 8 follicular lymphoma (FL), 7 marginal zone lymphoma (MZL) (1 splenic, 2 extranodal, and 4 nodal), 15 Waldenström's macroglobulinemia (WM), 1 lymphoplasmacytic lymphoma, 1 small lymphocytic lymphoma, and 1 low‐grade B‐cell lymphoma with plasmacytic differentiation (unable to be classified better as MZL or LPL). Hematologic toxicity was the most common adverse event. Median time of follow‐up was 23.4 months (range 1.8–50.9). The overall response rate was 87.9%, with 30.3% complete response. The median duration of response was 38.7 months. The median progression free survival was 39.7 months, while median overall survival (OS) has not yet been reached. Lenalidomide can be safely added to a simple regimen of rituximab, oral cyclophosphamide, and dexamethasone and is an effective combination as initial therapy for low‐grade B‐cell NHL.  相似文献   
34.
35.
A non-total body irradiation-containing preparative regimen was studied in young children (<4 years old) undergoing unrelated donor cord blood transplantation as part of the Cord Blood Transplantation trial for the treatment of acute lymphoblastic leukemia (n = 14), acute myeloid leukemia (n = 13), undifferentiated leukemia (n = 1), juvenile myelomonocytic leukemia (n = 2), and myelodysplastic syndromes (n = 2). Donor/recipient HLA matching based on low-/intermediate-resolution molecular typing for HLA-A and -B and high-resolution HLA-DRB1 typing was 5/6 or 6/6 (n = 21) or 4/6 (n = 11). The preparative therapy consisted of busulfan, melphalan, and antithymocyte globulin, with cyclosporine and corticosteroids for graft-versus-host disease (GVHD) prophylaxis. The median age was 1.6 years (range, 0.5-3.9 years), and the median weight was 10.5 kg (range, 5.8-19.5 kg). Cord blood grafts contained a median of 10.7 x 10 7 nucleated cells per kilogram (range, 4.6-29.2) and 2.6 x 10(5) CD34+ cells per kilogram (range, 0.7-8.3). The cumulative incidence (CINC) of neutrophil recovery (absolute neutrophil count >500/microL) at day 42 was 0.59 (95% confidence interval [CI], 0.44-0.78) at a median of 31 days (range, 23-55 days). The CINC and Kaplan-Meier estimates of platelet engraftment at day 180 were 0.53 (95% CI, 0.34-0.69) and 0.82 (95% CI, 0.61-1.00), respectively. CINC estimates of grade III/IV acute GVHD at day 100 and chronic GVHD at 1 year were 0.25 (95% CI, 0.09-0.41) and 0.26 (95% CI, 0.09-0.44), respectively. The CINC estimate of relapse was 0.31 (95% CI, 0.16-0.47) at 2 years. With a median follow-up of 27.8 months (range, 23.4-46.7 months), the probability of survival at 1 year was 0.47 (95% CI, 0.30-0.64). A preparative regimen containing a busulfan/melphalan/antithymocyte globulin preparative regimen is well tolerated in the setting of unrelated donor cord blood transplantation for childhood leukemia and can serve as a platform preparative regimen for intensifying host immunosuppression and antileukemic therapy to allow for improved engraftment and improved relapse-free survival.  相似文献   
36.
In recent years interest in the anatomy of corpus callosum (CC) has led to a number of studies on morphometric analysis of CC, either in vivo on magnetic resonance imaging (MRI) or on preserved (formalin-fixed) cadaveric brain specimens. There are very few reports comparing the values obtained by both these methodologies, and to the authors' knowledge no study of CC morphometry in fresh (unfixed) autopsy brains has been done. Morphometric measurements of the CC were done on fresh autopsy brains ( n  = 15), preserved cadaveric brains ( n  = 44) and MRI scans ( n  = 30) in adults (age range: 20–60 years) of both sexes without any intracranial brain pathology, in north-west Indian subjects. Most of the CC measurements were found to be more in the fresh autopsy brain group as compared to the preserved cadaveric brain and MRI group. The distance between the splenium and superior colliculus in the fresh autopsy brain group was almost twice that in the other two groups. In addition, there was a similarity between the preserved cadaveric brain and MRI values for most of the parameters, but the distances between the genu and fornix and between the genu and anterior commissure were larger in the MRI group as compared to the other two groups. The present data may be of value in studying deviations from the normal in various disease processes as well in surgical planning of intraventricular and callosal pathologies.  相似文献   
37.
Palmaris longus muscle, although of little functional use to the human upper limb, assumes great importance when used as a donor tendon for transfer or transplant. The variability in the prevalence of palmaris longus agenesis among various ethnic groups has been established, and the surgeon's awareness of the prevalence in a population or ethnic group is desirable. The prevalence of palmaris longus agenesis has, to the best of the authors' knowledge, not been reported in Indian patients. Five hundred Indian patients were examined for the presence or absence of palmaris longus tendon, using the conventional test for presence of palmaris longus. The prevalence and pattern of palmaris longus agenesis was analyzed statistically and any difference in prevalence or pattern of palmaris longus agenesis with regard to body side or sex was looked for. All statistical analysis was done using SPSS (version 12). chi2 test was used to analyze the association of agenesis with limb laterality and sex. The prevalence of palmaris longus agenesis was found to be 17.2% (8% bilateral and 9.2% unilateral). The prevalence of agenesis was significantly more common on the left side. Male subjects had a greater likelihood of unilateral agenesis, while female subjects were more likely to have bilateral agenesis. That prevalence of palmaris longus agenesis is race dependent is reaffirmed in the present study. Although the prevalence of palmaris longus agenesis in Indian patients was found to be much higher than the reported average prevalence in an Asian population, this tendon can still be counted on by surgeons treating Indian patients for use as a donor tendon, which will be present in a vast majority of Indian patients.  相似文献   
38.
39.
BACKGROUND & AIMS: Variability in response to drugs may influence both efficacy and safety. Cyclooxygenase (COX)-2 inhibitors pose a cardiovascular risk by potentially increasing the likelihood of thrombosis, hypertension, and atherogenesis. Differences between individuals in the response to COX-2 inhibitors would be expected to influence their susceptibility to cardiovascular complications. We examined the variability in degree and selectivity of COX-2 inhibition in humans in response to celecoxib and rofecoxib. METHODS: Fifty healthy volunteers received placebo, rofecoxib (25 mg), and celecoxib (200 mg), randomized by order. COX-1 and COX-2 inhibition was determined using ex vivo and in vivo indices of enzymatic activity. A subset of 5 individuals underwent 5 replicate studies to estimate variability in drug response both within and between subjects. RESULTS: Despite the higher COX-2 selectivity of rofecoxib in vitro, the average selectivity attained by 25 mg rofecoxib and 200 mg celecoxib in vivo were not different. However, there was considerable variability at an individual level in the degree of COX-2 inhibition and selectivity attained by both drugs. Approximately one third of the variability was attributable to differences between individuals, suggesting the contribution of genetic sources of variance, such as candidate polymorphisms detected in COX-1 and CYP2C9. CONCLUSIONS: The actual degree of selectivity for inhibition of COX-2 achieved by the coxibs relates both to chemical properties of the drug and to factors within an individual that modulate drug response. These sources of variability might be exploited to identify patients uniquely susceptible to benefit or at developing risk of cardiovascular complications.  相似文献   
40.
BACKGROUND: The Suguira procedure is an effective non-shunting operation to treat life-threatening hemorrhage from esophageal or gastric varices. The goal of esophageal transection is interruption of submucosal varices, but this leads to high morbidity and mortality rates from esophageal fistulization. AIM: To evaluate a variant of this procedure in which the esophagus is not transected, but the varices are underrun from outside the lumen. METHODS: During the last four and a half years, we performed this modified gastroesophageal devascularization with or without splenectomy in 18 patients as emergency treatment of bleeding esophageal and gastric varices. The data were analyzed retrospectively. RESULTS: Bleeding was controlled in all patients. Three patients with Child's class C disease undergoing emergency surgery died during the early postoperative period. Rebleeding rate was 17% (3 patients). The overall survival was 72.2% (13 of 18). No patient had encephalopathy over a mean follow up of 30 months. CONCLUSION: Gastroesophageal devascularization with variceal under-running without esophageal transection is an effective and safe alternative to shunt surgery in the emergency situation.  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