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   2607篇
  免费   127篇
  国内免费   12篇
耳鼻咽喉   23篇
儿科学   96篇
妇产科学   36篇
基础医学   346篇
口腔科学   25篇
临床医学   187篇
内科学   569篇
皮肤病学   30篇
神经病学   384篇
特种医学   101篇
外科学   247篇
综合类   28篇
预防医学   119篇
眼科学   268篇
药学   112篇
中国医学   1篇
肿瘤学   174篇
  2022年   24篇
  2021年   45篇
  2020年   18篇
  2019年   40篇
  2018年   46篇
  2017年   40篇
  2016年   55篇
  2015年   75篇
  2014年   75篇
  2013年   96篇
  2012年   172篇
  2011年   177篇
  2010年   111篇
  2009年   90篇
  2008年   150篇
  2007年   131篇
  2006年   124篇
  2005年   131篇
  2004年   141篇
  2003年   114篇
  2002年   127篇
  2001年   58篇
  2000年   49篇
  1999年   41篇
  1998年   24篇
  1997年   31篇
  1996年   22篇
  1995年   13篇
  1994年   15篇
  1993年   12篇
  1992年   36篇
  1991年   28篇
  1990年   21篇
  1989年   26篇
  1988年   22篇
  1987年   24篇
  1986年   18篇
  1985年   15篇
  1984年   13篇
  1983年   12篇
  1979年   11篇
  1978年   15篇
  1977年   17篇
  1975年   13篇
  1974年   14篇
  1973年   15篇
  1972年   13篇
  1971年   12篇
  1970年   13篇
  1966年   14篇
排序方式: 共有2746条查询结果,搜索用时 15 毫秒
51.
52.

Background:

Many patients with obsessive-compulsive disorder do not respond adequately to serotonin reuptake inhibitors. Augmentation with antipsychotic drugs can be beneficial in this regard. However, since new relevant randomized controlled trials evaluating new antipsychotics were conducted, a recalculation of the effect sizes appears necessary.

Methods:

We meta-analyzed all double-blind, randomized, placebo-controlled trials comparing augmentation of serotonin reuptake inhibitors with antipsychotics to placebo supplementation in treatment-resistant obsessive-compulsive disorder. The primary outcome was mean change in the Yale-Brown Obsessive–Compulsive Scale total score. Secondary outcomes were obsessions, compulsions, response rates, and attrition rates. The data collection process was conducted independently by 2 authors. Hedges’s g and risks ratios were calculated as effect sizes. In preplanned meta-regressions, subgroup analyses, and sensitivity analyses, we examined the robustness of the results and explored reasons for potential heterogeneity.

Results:

Altogether, 14 double-blind, randomized, placebo-controlled trials (n=491) investigating quetiapine (N=4, n=142), risperidone (N=4, n=132), aripiprazole (N=2, n=79), olanzapine (N=2, n=70), paliperidone (N=1, n=34), and haloperidol (N=1, n=34) were incorporated. Augmentation with antipsychotics was significantly more efficacious than placebo in Yale-Brown Obsessive–Compulsive Scale total reduction (N=14, n=478; Hedges’s g=-0.64, 95% CI: -0.87 to -0.41; P=<.01). Aripiprazole (Hedges’s g=-1.35), haloperidol (Hedges’s g=-0.82), and risperidone (Hedges’s g=-0.59) significantly outperformed placebo. Antipsychotics were superior to placebo in treating obsessions, compulsions, and achieving response. There was no between-group difference concerning all-cause discontinuation. The nonsignificant meta-regressions suggest no influence of the antipsychotic dose or baseline symptom severity on the meta-analytic results.

Conclusions:

According to our findings, antipsychotic augmentation of serotonin reuptake inhibitors can be regarded as an evidence-based measure in treatment-resistant obsessive-compulsive disorder.  相似文献   
53.
Purpose

Pulmonary function testing (PFT) in patients with tracheostomies has been perceived as difficult to perform and clinically unreliable. We studied the feasibility, quality, repeatability and clinical significance of PFT.

Methods

Patients with tracheostomies that underwent PFT from January 1, 2010 to February 29, 2012 were identified. Clinical history and PFT data were reviewed retrospectively.

Results

Fifty patients (88% men) were identified. Forty-seven (94%) patients were able to perform PFT. Acceptable repeatability was obtained for FVC in 39 (83%) and for FEV1 in 41 (87%). Patients with tracheostomies showed difficulty in meeting ATS end-of-test criteria; only 9 (19%) met plateau criteria and 25 (53%) had exhalation times of greater than 6 s. Obstructive pattern was observed in 30 (64%) and restrictive pattern in 9 (19%). DLCO measurements were attempted in 43 patients and satisfactorily obtained in 34 (79%).

Conclusions

PFT can be performed with reliability in patients with tracheostomies, and they are useful for detecting and classifying types of lung dysfunction.

  相似文献   
54.
Endothelin (ET) is a broncho- and vasoconstrictive cytokine, but it also possesses proinflammatory and mitogenic activity. It is suggested to be involved in the pathogenesis of fibrotic lung diseases. We analyzed the concentration of ET 1 in the bronchoalveolar lavage (BAL) fluid in 95 patients with different lung diseases, among them 41 patients with interstitial lung diseases (13 fibrosing alveolitis in systemic sclerosis (FASS), 9 idiopathic pulmonary fibrosis (IFP), 8 sarcoidosis (S), 6 occupational lung disease (OLD), 5 other alveolitidies A), 27 patients with pneumonia, and 8 patients with chronic obstructive pulmonary disease (COPD). A heterogeneous group of 19 patients served as controls. The median ET concentration was 3.3 pg/ml. Significantly higher concentration was found in patients with FASS (5.8 pg/ml), IPF (5.0 pg/ml), and S (5.1 pg/ml) compared with OLD (2.8 pg/ml), A (1.9 pg/ml), COPD (1.5 pg/ml), and the control group (2.5 pg/ml). In pneumonia, the elevated ET concentration (4.1 pg/ml) was accompanied by a high alveolocapillary leakage. When normalized to BAL albumin concentration, only FASS presented with significantly elevated ET/albumin in the BAL compared with the control group (134.5 vs. 56.l pg/mg, p < 0.05). There were no correlations between ET and BAL differential cell count or pulmonary function tests. In current smokers, ET in BALF was significantly higher compared with non- or ex-smokers (3.9 vs. 2.0 pg/ml, p < 0.01), but not so the ET/albumin ratio (65.0 vs. 62.5 pg/mg). In summary, ET in the BAL is differentially expressed in distinct inflammatory and interstitial lung disease. Consistently high concentrations are found in FASS and elevated ET concentration could be discussed in IPF, sarcoidosis, and pneumonia. ET concentration in BAL is influenced by current smoking habits.  相似文献   
55.
Without transplantation from a human leucocyte antigen-identical family donor, refractory severe aplastic anaemia (SAA) has an unfavourable prognosis. Conventional transplantation from a matched unrelated donor carries a high rate of mortality. We transplanted large numbers of highly purified CD34+ cells from matched unrelated (n = 4), mismatched unrelated (n = 4) and mismatched related (n = 1) donors into nine children with refractory SAA. The grafts consisted of granulocyte colony-stimulating factor-mobilized peripheral positively selected CD34+ cells. A median of 15.1 x 106/kg CD34+ stem cells and 11 x 103/kg CD3+ T-lymphocytes were infused. No additional pharmacological graft versus host disease (GVHD) prophylaxis was given. At a median follow-up of 47 (range 37-72) months, eight patients (89%) were in complete remission with >90% donor chimaerism and no evidence of GVHD. One patient died on day +238 as a consequence of GVHD. The use of highly purified mobilized CD34+ stem cells warrants further clinical exploration in children with refractory SAA.  相似文献   
56.
Heparin-induced thrombocytopenia (HIT) appears rarely in pregnant patients who are being treated with heparin. When HIT is suspected, heparin treatment should be discontinued and alternative anticoagulation should be started. The heparinoid danaparoid appears to be the drug of choice for acute treatment and prophylaxis because of its low placental permeability. Between the 12th and 36th weeks of pregnancy, either danaparoid may be continued or warfarin may be used after recovery of platelet counts. Before and during delivery, danaparoid should be preferred over warfarin in order to avoid bleeding complications in mother and infant. Hirudin should only be used when either cross-reactivity with heparin-induced antibodies or cutaneous allergy against heparinoids are observed. Postpartum warfarin seems to be the treatment of choice because breast-feeding can be continued. Alternative treatment with either danaparoid or hirudin is possible, but data on treatment with these reagents in lactating mothers are very limited.  相似文献   
57.
Haploidentical hematopoietic cell transplantation (HHCT) after high dose conditioning with CD34-selected stem cells has been complicated by high regimen related toxicities, slow engraftment and delayed immune reconstitution leading to increased treatment related mortality (TRM). A new regimen using reduced intensity conditioning (RIC) and graft CD3/CD19 depletion with anti-CD3 and anti-CD19 coated microbeads on a CliniMACS device may allow HHCT with lower toxicity and faster engraftment. CD3/CD19 depleted grafts not only contain CD34+ stem cells but also CD34 negative progenitors, natural killer, graft facilitating and dendritic cells. RIC was performed with fludarabine (150-200 mg/m(2)), thiotepa (10 mg/kg), melphalan (120 mg/m(2)) and OKT-3 (5 mg/day, day -5 to +14) and no posttransplant immunosuppression. Twenty nine patients (median age=42 (range, 21-59) years) have been transplanted with this regimen. Diagnosis were AML (n=16), ALL (n=7), NHL (n=3), MM (n=2) and CML (n=1). Patients were "high risk" with refractory disease or relapse after preceding HCT. The CD3/CD19 depleted haploidentical grafts contained a median of 7.6x10(6) (range, 3.4-17x10(6)) CD34+ cells/kg, 4.4x10(4) (range, 0.006-44x10(4)) CD3+ T cells/kg and 7.2x10(7) (range, 0.02-37.3x10(7)) CD56+ cells/kg. Donor-recipient KIR-ligand-mismatch was found in 19 of 29 patients. The regimen was well tolerated with maximum acute toxicity being grade 2-3 mucositis. Because of severe neurotoxicity in 4 patients treated with 200 mg/m(2) fludarabine, the dose was reduced to 150 mg/m(2). Engraftment was rapid with a median time to >500 granulocytes/microL of 12 (range, 10-21) days, >20,000 platelets/microL of 11 (range, 7-38) days and full donor chimerism after 2-4 weeks in all patients. Incidence of grade II-IV degrees GVHD was 48% with grade II degrees =10, III degrees =2 and IV degrees =2. One patient, who received the highest T-cell dose, developed lethal grade IV GVHD. TRM in the first 100 days was 6/29 (20%) with deaths due to idiopathic pneumonia syndrome (n=1), mucormycosis (n=1), pneumonia (n=3) or GVHD (n=1). Overall survival is 9/29 patients (31%) with deaths due to infections (n=7), GVHD (n=1) and relapse (n=12) with a median follow-up of 241 days (range, 112-1271). In conclusion, this regimen is promising in high risk patients lacking a suitable donor, and a prospective phase I/II study is ongoing.  相似文献   
58.
59.
Summary The temporary skin-level loop transverse colostomy has been described. Proof of its ability to divert the fecal stream totally is illustrated by complete diversion in 25 patients ingesting a postcolostomy barium meal. There was no postoperative complication. Department of Colon and Rectal Surgery.  相似文献   
60.
OBJECTIVE: The existence of adult, marrow-derived stem cells that retain the ability to generate various tissues is an appealing concept that has considerable therapeutic potential. The aim of this study was to test the extent of this proposed plasticity by defining the ability of adult marrow and peripheral blood stem cells to generate stromal cells of the marrow microenvironment. PATIENTS AND METHODS: We examined expanded populations of stromal cells from four patients 1 to 27 years after allogeneic, sex-mismatched marrow, or peripheral blood stem cell transplantation. The cultured stromal cells were stained by immunofluorescence and with nonspecific esterase (NSE) to detect macrophages, which can constitute a significant component of a primary long-term marrow culture. Fluorescence in situ hybridization (FISH) probes for chromosomes X and Y were applied to distinguish donor from host cells. RESULTS: FISH analysis of replicate slides indicated a good correlation between the number of NSE(+) cells and the number of donor-derived cells. By applying NSE and FISH to the same cells and capturing both bright-field and epifluorescence images, we confirmed that all donor signals were derived from NSE(+) macrophages. CONCLUSION: After successful allogeneic stem cell transplantation, the marrow stroma remains host in origin, even after 27 years of 100% donor hematopoiesis.  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