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   1305篇
  免费   49篇
  国内免费   5篇
耳鼻咽喉   4篇
儿科学   71篇
妇产科学   65篇
基础医学   135篇
口腔科学   14篇
临床医学   111篇
内科学   233篇
皮肤病学   7篇
神经病学   52篇
特种医学   44篇
外科学   160篇
综合类   4篇
预防医学   42篇
眼科学   10篇
药学   172篇
中国医学   5篇
肿瘤学   230篇
  2023年   10篇
  2022年   5篇
  2021年   30篇
  2020年   17篇
  2019年   25篇
  2018年   30篇
  2017年   22篇
  2016年   27篇
  2015年   32篇
  2014年   50篇
  2013年   57篇
  2012年   85篇
  2011年   66篇
  2010年   38篇
  2009年   46篇
  2008年   74篇
  2007年   67篇
  2006年   80篇
  2005年   72篇
  2004年   54篇
  2003年   49篇
  2002年   43篇
  2001年   39篇
  2000年   46篇
  1999年   41篇
  1998年   8篇
  1997年   6篇
  1996年   11篇
  1995年   12篇
  1994年   4篇
  1993年   5篇
  1992年   26篇
  1991年   19篇
  1990年   25篇
  1989年   14篇
  1988年   19篇
  1987年   21篇
  1986年   18篇
  1985年   18篇
  1984年   14篇
  1983年   9篇
  1982年   2篇
  1981年   7篇
  1978年   2篇
  1974年   1篇
  1972年   3篇
  1970年   2篇
  1969年   3篇
  1968年   1篇
  1967年   1篇
排序方式: 共有1359条查询结果,搜索用时 77 毫秒
1.
2.
3.
We sought to describe the common causes of infection in patients presenting to the Emergency Department (ED) with elevated temperature and chemotherapy-induced neutropenia and to determine the frequency with which the ED diagnosis of infection is consistent with the final hospital discharge diagnosis. We performed a structured restrospective chart review of ED patients with fever (T > 38 degrees C) and neutropenia (absolute neutrophil count < 1000/mm(3)) over a 2-year period. Fifty-five episodes of neutropenic fever occurred in 52 patients (mean age 52 years, range 18-86 years; 53% men). Twenty-six patients (47%) were found to have a specific infection identified. Of these, 21/26 (81%; 95% CI, 70-91%) had the source of infection identified while in the ED. All patients who had a focal site of infection identified during their hospitalization were diagnosed in the ED (100%; 95% CI, 86-100%). The other 5 patients, without a source identified in the ED, were found to have bacteremia. The 29 patients without a source identified in the ED were hospitalized and had negative blood and urine cultures and were discharged to home after resolution of fever. A thorough history, physical examination, chest radiograph and urinalysis in the ED identified all patients with a focus of infection. Meticulous ED evaluation of patients with neutropenia and fever may be sufficient to diagnose most sources of infection; however, a significant number of patients without an identifiable focus may have bacteremia.  相似文献   
4.

Background

An Artificial Placenta (AP) utilizing extracorporeal life support (ECLS) could revolutionize care of extremely premature newborns, but its effects on gastrointestinal morphology and injury need investigation.

Methods

Lambs (116–121 days GA, term = 145; n = 5) were delivered by C-section, cannulated for ECLS, had total parenteral nutrition (TPN) provided, and were supported for 7 days before euthanasia. Early and Late Tissue Controls (ETC, n = 5 and LTC, n = 5) delivered at 115–121 days and 125–131 days, respectively, were immediately sacrificed. Standardized jejunal samples were formalin-fixed for histology. Crypt depth (CD), villus height (VH), and VH:CD ratios were measured. Measurements also included enterocyte proliferation (Ki-67), Paneth cell count (Lysozyme), and injury scores (H&E). ANOVA and Chi Square were used with p < 0.05 considered significant.

Results

CD, VH, and VH:CD were similar between groups (p > 0.05). AP demonstrated more enterocyte proliferation (95.7 ± 21.8) than ETC (49.4 ± 23.4; p = 0.003) and LTC (66.1 + 11.8; p = 0.04), and more Paneth cells (81.7 ± 17.5) than ETC (41.6 ± 7.0; p = 0.0005) and LTC (40.7 ± 8.2, p = 0.0004). Presence of epithelial injury and congestion in the bowel of all groups were not statistically different. No villus atrophy or inflammation was present in any group.

Conclusions

This suggests preserved small bowel mucosal architecture, high cellular turnover, and minimal evidence of injury.

Study type

Research paper/therapeutic potential.

Level of evidence

N/A  相似文献   
5.
6.

Background

Outcomes of neoadjuvant chemotherapy in patients with muscle-invasive urothelial bladder carcinoma (MIUBC) should be improved. Sorafenib was combined with gemcitabine and cisplatin chemotherapy (SGC) in an open-label, single-arm, phase 2 trial (NCT01222676).

Patients and methods

After transurethral resection of the bladder, T2–T4a N0 patients received four cycles of SGC followed by cystectomy. Sorafenib 400 mg q12h daily, continuously, was added to standard GC chemotherapy. In a Simon's 2-stage design, the primary endpoint was the pathologic complete response (pT0), assuming H0: ≤0.20 and H1: ≥0.40, with a type I and type II error of 5% and 10%, respectively.

Results

From April 2011 to June 2016, 46 patients were enrolled. Pathologic T0 response was obtained in 20 patients (43.5%, 95% CI: 28.9–58.9); pT ≤ 1 in 25 (54.3%, 95% CI: 39.0–69.1). After a median follow-up of 35 months, the median progression-free survival was not reached (NR, interquartile range: 23.6–NR), nor was median overall survival (interquartile range: 30.3–NR). Hematologic and extrahematologic grade 3 to 4 adverse events occurred in 45.6% and 26.1% of patients, respectively. In 29 samples from responders (pT ≤ 1) and nonresponders, different distribution of missense mutations involved DNA-repair genes, RAS-RAF pathway genes, chromatin-remodeling genes, and HER-family genes. ERCC1 immunohistochemical expression was associated with pT ≤ 1 response (P = 0.047). The absence of a comparator arm prevented us to quantify sorafenib contribution.

Conclusions

SGC combination was active in MIUBC, and the identified molecular features included alterations that may help personalize treatment in MIUBC with new more potent targeted agents, combined with chemotherapy.  相似文献   
7.
A wait and see approach for desmoid tumors (DT) has become part of the routine treatment strategy. However, predictive factors to select the risk of progressive disease are still lacking. A translational project was run in order to identify genomic signatures in patients enrolled within an Italian prospective observational study. Among 12 DT patients (10 CTNNB1‐mutated and 2 wild type) enrolled from our institution only two patients (17%) showed a progressive disease. Tumor biopsies were collected for whole exome sequencing. Overall, DT exhibited low somatic sequence mutation rate and no additional recurrent mutation was found. In the two wild type (WT) cases, two novel alterations were detected: a complex deletion of APC and a pathogenic mutation of LAMTOR2. Focusing on WT DT subtype, deep sequencing of CTNNB1, APC and LAMTOR2 was conducted on a retrospective series of 11 WT DT using a targeted approach. No other mutation of LAMTOR2 was detected, while APC was mutated in two cases. Low‐frequency (mean reads of 16%) CTNNB1 mutations were discovered in five samples (45%) and two novel intra‐genic deletions in CTNNB1 were detected in two cases. Both deletions and low frequency mutations of CTNNB1 were highly expressed. In conclusion, a minority of DT is WT for either CTNNB1, APC or any other gene involved in the WNT pathway. In this subgroup novel and hard to be detected molecular alterations in APC and CTNNB1 were discovered, contributing to explain a portion of the allegedly WT DT cases.  相似文献   
8.
Extracellular matrix (ECM) scaffolds have been used to enhance anterior cruciate ligament (ACL) repair in large animal models. To translate this technology to clinical care, identifying a method which effectively sterilizes the material without significantly impairing in vivo function is desirable. Sixteen Yorkshire pigs underwent ACL transection and were randomly assigned to bridge‐enhanced ACL repair—primary suture repair of the ACL with addition of autologous blood soaked ECM scaffold—with either (i) an aseptically processed ECM scaffold, or (ii) an electron beam irradiated ECM scaffold. Primary outcome measures included sterility of the scaffold and biomechanical properties of the scaffold itself and the repaired ligament at 8 weeks after surgery. Scaffolds treated with 15 kGy electron beam irradiation had no bacterial or fungal growth noted, while aseptically processed scaffolds had bacterial growth in all tested samples. The mean biomechanical properties of the scaffold and healing ligament were lower in the electron beam group; however, differences were not statistically significant. Electron beam irradiation was able to effectively sterilize the scaffolds. In addition, this technique had only a minimal impact on the in vivo function of the scaffolds when used for ligament healing in the porcine model. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1015–1023, 2015.  相似文献   
9.
10.
Reprogramming of metabolism is a well-established property of cancer cells that is receiving growing attention as potential therapeutic target. Oral squamous cell carcinomas (OSCC) are aggressive and drugs-resistant human tumours displaying wide metabolic heterogeneity depending on their malignant genotype and stage of development. Dichloroacetate (DCA) is a specific inhibitor of the PDH-regulator PDK proved to foster mitochondrial oxidation of pyruvate. In this study we tested comparatively the effects of DCA on three different OSCC-derived cell lines, HSC-2, HSC-3, PE15. Characterization of the three cell lines unveiled for HSC-2 and HSC-3 a glycolysis-reliant metabolism whereas PE15 accomplished an efficient mitochondrial oxidative phosphorylation. DCA treatment of the three OSCC cell lines, at pharmacological concentrations, resulted in stimulation of the respiratory activity and caused a remarkably distinctive pro-apoptotic/cytostatic effect on HSC-2 and HSC-3. This was accompanied with a large remodeling of the mitochondrial network, never documented before, leading to organelle fragmentation and with enhanced production of reactive oxygen species. The data here presented indicate that the therapeutic efficacy of DCA may depend on the specific metabolic profile adopted by the cancer cells with those exhibiting a deficient mitochondrial oxidative phosphorylation resulting more sensitive to the drug treatment.  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