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   374篇
  免费   39篇
  国内免费   1篇
耳鼻咽喉   2篇
儿科学   30篇
妇产科学   14篇
基础医学   65篇
口腔科学   3篇
临床医学   14篇
内科学   63篇
皮肤病学   4篇
神经病学   87篇
特种医学   6篇
外科学   49篇
综合类   4篇
预防医学   6篇
眼科学   2篇
药学   28篇
肿瘤学   37篇
  2022年   3篇
  2021年   2篇
  2020年   3篇
  2019年   4篇
  2018年   7篇
  2017年   5篇
  2016年   11篇
  2015年   11篇
  2014年   11篇
  2012年   4篇
  2011年   5篇
  2010年   4篇
  2009年   8篇
  2008年   19篇
  2007年   18篇
  2006年   25篇
  2005年   25篇
  2004年   21篇
  2003年   23篇
  2002年   29篇
  2001年   23篇
  2000年   13篇
  1999年   16篇
  1998年   6篇
  1997年   7篇
  1996年   3篇
  1995年   5篇
  1994年   3篇
  1993年   2篇
  1992年   9篇
  1991年   9篇
  1990年   4篇
  1989年   7篇
  1988年   6篇
  1987年   4篇
  1986年   5篇
  1985年   3篇
  1984年   3篇
  1983年   5篇
  1981年   2篇
  1978年   2篇
  1976年   5篇
  1975年   3篇
  1970年   2篇
  1969年   4篇
  1932年   2篇
  1925年   2篇
  1920年   2篇
  1912年   1篇
  1906年   1篇
排序方式: 共有414条查询结果,搜索用时 15 毫秒
101.
102.

Background

Although therapeutic guidelines recommend the use of neoadjuvant chemotherapy before radical cystectomy (RC) in patients who have muscle-invasive bladder cancer (MIBC), this approach remains largely underused. One of the main reasons for this phenomenon might reside in concerns regarding the risk of morbidity and mortality associated with neoadjuvant chemotherapy.

Objective

To compare perioperative outcomes between patients receiving neoadjuvant chemotherapy and those treated with RC alone.

Design, setting, and participants

Relying on the Surveillance Epidemiology and End Results–Medicare-linked database, 3760 patients diagnosed with MIBC between 2000 and 2009 were evaluated.

Intervention

RC alone or RC plus neoadjuvant chemotherapy.

Outcome measurements and statistical analysis

Complications occurred within 30 and 90 d after surgery. Heterologous blood transfusions (HBTs), length of stay (LoS), readmission, and perioperative mortality were compared. To decrease the effect of unmeasured confounders associated with treatment selection, propensity score–matched analyses were performed.

Results and limitations

Overall, 416 (11.1%) of patients received neoadjuvant chemotherapy. Following propensity score matching, 416 (20%) and 1664 (80%) patients treated with RC plus neoadjuvant chemotherapy and RC alone remained, respectively. The 30-d complication, readmission, and mortality rates were 66.0%, 32.2%, and 5.3%, respectively. The 90-d complication, readmission, and mortality rates were 72.5%, 46.6%, and 8.2%, respectively. When patients were stratified according to neoadjuvant chemotherapy status, no significant differences were observed in the rates of complications, HBT, prolonged LoS, readmission, and mortality between the two groups (all p ≥ 0.1). These results were confirmed in multivariate analyses, where the use of neoadjuvant chemotherapy was not associated with higher risk of 30- and 90-d complications, HBT, prolonged LoS, readmission, and mortality (all p ≥ 0.1). Our study is limited by its retrospective nature.

Conclusions

The use of neoadjuvant chemotherapy is not associated with higher perioperative morbidity or mortality. These results should encourage wider use of neoadjuvant chemotherapy when clinically indicated.

Patient summary

Chemotherapy before radical cystectomy in patients with muscle-invasive bladder cancer does not increase the risk of complications or death. The use of chemotherapy should be strongly encouraged, as recommended by clinical guidelines, given its benefits.  相似文献   
103.
Fabry disease is a lysosomal storage disorder that is due to a deficiency in alpha-galactosidase A (alpha-gal A). Previously we have shown that a recombinant retrovirus synthesized for the transfer of the human alpha-gal A coding sequence was able to engineer enzymatic correction of the hydrolase deficiency in fibroblasts and lymphoblasts from Fabry patients. The corrected cells secreted alpha-gal A that was taken up and utilized by uncorrected bystander cells, thus demonstrating metabolic cooperativity. In separate experiments we used transduced murine bone marrow cells and successfully tested and quantitated this phenomenon in vivo. In the present studies, which were designed to bring this therapeutic approach closer to clinical utility, we establish that cells originating from the bone marrow of numerous Fabry patients and normal volunteers can be effectively transduced and that these target cells demonstrate metabolic cooperativity. Both isolated CD34+-enriched cells and long-term bone marrow culture cells, including nonadherent hematopoietic cells and adherent stromal cells, were transduced. The transferred gene generates increased intracellular alpha-gal A enzyme activity in these cells. Further, it causes functional correction of lipid accumulation and provides for long-term alpha-gal A secretion. Collectively, these results indicate that a multifaceted gene transfer approach to bone marrow cells may be of therapeutic benefit for patients with Fabry disease.  相似文献   
104.
An approach to teaching the introduction of clinical medicine to medical students is described. It is based on (A) gradual exposure to patients and step-by-step introduction to the objectives and techniques of history taking, with emphasis on training for symptom identification; (B) early exposure to the problem-oriented approach; (C) early diagnostic hypothesis generation; and (D) self-directed learning. The objectives of the proposed approach are to teach students to communicate with patients, to teach the skills of history taking and physical examination, and to introduce the problem-solving strategies that characterize the diagnostic reasoning of experienced physicians.  相似文献   
105.
In the cerebellum, the parallel fiber-Purkinje cell synapse can undergo long-term synaptic plasticity suggested to underlie motor learning and resulting from variations in intracellular calcium concentration ([Ca2+]i). Ca2+ binding proteins are enriched in the cerebellum, but their role in information processing is not clear. Here, we show that mice deficient in calretinin (Cr-/-) are impaired in tests of motor coordination. An impairment in Ca2+ homeostasis in Cr-/- Purkinje cells was supported by the high Ca2+-saturation of calbindin-D28k in these cells. The firing behavior of Purkinje cells is severely affected in Cr-/- alert mice, with alterations of simple spike firing rate, complex spike duration, and simple spike pause. In contrast, in slices, transmission at parallel fiber- or climbing fiber-Purkinje cell synapses is unaltered, indicating that marked modifications of the firing behavior in vivo can be undetectable in slice. Thus, these results show that calretinin plays a major role at the network level in cerebellar physiology.  相似文献   
106.
107.
N-formylmethionyl peptides as chemoattractants for leucocytes.   总被引:74,自引:16,他引:74       下载免费PDF全文
Leucocytes such as neutrophils are attracted by N-formylmethionine, but not by methionine. Di- and tripeptides containing formylmethionine are strong attractants for both neutrophils and macrophages, whereas the corresponding nonacylated compounds are not chemotactic. The formylated peptides may be related to an incompletely characterized chemotactic material normally produced by bacteria which attract the same animal cells.  相似文献   
108.

Background

Adult polyglucosan body disease (APBD) is a progressive neurometabolic disorder caused by a deficiency of glycogen branching enzyme. We tested the efficacy of triheptanoin as a therapy for patients with APBD based on the hypothesis that decreased glycogen degradation leads to brain energy deficit.

Methods and results

This was a two-site, randomized crossover trial of 23 patients (age 35–73 years; 63% men) who received triheptanoin or vegetable oil as placebo. The trial took place over 1 year and was followed by a 4-year open-label phase. Generalized linear mixed models were used to analyze this study. At baseline, using the 6-min walk test, patients could walk a mean of 389 ± 164 m (range 95–672; n = 19), highlighting the great clinical heterogeneity of our cohort. The overall mean difference between patients on triheptanoin versus placebo was 6 m; 95% confidence interval (CI) ?11 to 22; p = 0.50. Motion capture gait analysis, gait quality, and stair climbing showed no consistent direction of change. All secondary endpoints were statistically nonsignificant after false discovery rate adjustment. Triheptanoin was safe and generally well tolerated. During the open-label phase of the study, the most affected patients at baseline kept deteriorating while mildly disabled patients remained notably stable up to 4 years.

Conclusions

We cannot conclude that triheptanoin was effective in the treatment of APBD over a 6-month period, but we found it had a good safety profile. This study also emphasizes the difficulty of conducting trials in very rare diseases presenting with a wide clinical heterogeneity. ClinicalTrials.gov Identifier: NCT00947960.
  相似文献   
109.
This study was performed to determine whether adult male patients with Fabry disease who demonstrate a continuing decline in renal function despite 2 to 4 yr of conventionally dosed agalsidase alfa therapy (0.2 mg/kg every other week [EOW]) show an improved slope of decline with weekly administration using the same dosage. Eleven (27%) of 41 adult male patients with Fabry disease who participated in long-term agalsidase alfa clinical trials and who had demonstrated a slope of decline in estimated GFR (eGFR) of > or =5 ml/min per 1.73 m(2)/yr while receiving long-term treatment with agalsidase alfa at the currently recommended dosage of 0.2 mg/kg, infused EOW, were enrolled in this open-label, prospective study. Patients were switched from EOW to weekly infusions and followed for an additional 24 mo. Before switching to weekly dosing, eGFR was 53.7 +/- 6.3 ml/min per 1.73 m(2) (mean +/- SEM), and mean rate of change in eGFR was -8.0 +/- 0.8 ml/min per 1.73 m(2)/yr. During the 24-mo follow-up period after switching to weekly dosing, the mean rate of change in eGFR was observed to slow to -3.3 +/- 1.4 ml/min/1.73 m(2)/yr (P = 0.01 versus EOW). After switching to weekly dosing, three patients demonstrated an improvement in eGFR and six patients demonstrated a slowing in the rate of eGFR decline; only two patients failed to improve their eGFR slope. A multiple regression model confirmed that the weekly infusion regimen was the strongest explanatory variable for the change in eGFR (P = 0.0008), with a weaker contribution from the concomitant use of angiotensin converting enzyme inhibitors/angiotensin receptor blockers (P = 0.02). These results suggest that weekly infusions of agalsidase alfa at a dosage of 0.2 mg/kg may be beneficial in the subgroup of patients who have Fabry disease and whose kidney function continues to decline after 2 to 4 yr or more of standard EOW dosing.  相似文献   
110.
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