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   1707篇
  免费   103篇
  国内免费   8篇
耳鼻咽喉   14篇
儿科学   40篇
妇产科学   30篇
基础医学   160篇
口腔科学   65篇
临床医学   165篇
内科学   405篇
皮肤病学   83篇
神经病学   109篇
特种医学   68篇
外科学   333篇
综合类   16篇
现状与发展   1篇
预防医学   75篇
眼科学   62篇
药学   91篇
中国医学   8篇
肿瘤学   93篇
  2023年   23篇
  2022年   39篇
  2021年   83篇
  2020年   61篇
  2019年   85篇
  2018年   85篇
  2017年   63篇
  2016年   67篇
  2015年   87篇
  2014年   100篇
  2013年   112篇
  2012年   142篇
  2011年   142篇
  2010年   72篇
  2009年   74篇
  2008年   140篇
  2007年   109篇
  2006年   110篇
  2005年   85篇
  2004年   51篇
  2003年   45篇
  2002年   26篇
  2001年   4篇
  2000年   1篇
  1999年   4篇
  1998年   3篇
  1997年   2篇
  1996年   3篇
排序方式: 共有1818条查询结果,搜索用时 62 毫秒
101.
102.
Metacarpophalangeal (MP) joint injuries and dislocations of the fingers and thumb are not uncommon. They can be classified directionally as either being volar or dorsal, and are further categorized as incomplete, simple complete or complex complete. Complex dislocations are described as dislocations that are irreducible and often require surgical intervention. This is often because tissue has become entrapped within the MP joint, precluding its anatomical reduction. For the thumb MP joint, anatomical structures that may become trapped include the volar plate, sesamoid bones, bony fracture fragments or the flexor pollicis longus tendon. Both dorsal and volar surgical approaches have been described, and their relative merits will be discussed. The unusual case of a late presentation (two months postinjury) of a complex complete dorsal dislocation of the thumb MP joint approached from a dorsal incision is presented.  相似文献   
103.
Patients and physicians often cite symptom control as one of their most important goals in cancer care. Despite this, a previous systematic review found few tools for evaluating the quality of supportive cancer management. We developed a comprehensive set of quality indicators for evaluating pain and nonpain symptom management as well as care planning needs in cancer patients. Based on the prevalence and quality-of-life data, clinician-researchers prioritized pain, psychosocial distress, dyspnea, nausea and vomiting, fatigue and anorexia, treatment-associated toxicities, and information and care planning for quality-indicator development. Using search terms and selection criteria, we identified English-language documents from Medline (1997–2007) and Internet-based searches. Based on this evidence, clinician-reviewers proposed process quality indicators. We then used the VA Health Services Research and Development (VA HSR & D) appropriateness methods to compile the ratings of a multidisciplinary, international expert panel of the validity and feasibility of each indicator. The panel judged 92 out of 133 (69%) proposed quality indicators valid and feasible (15 out of 23 pain, 5 out of 6 depression, 8 out of 11 dyspnea, 15 out of 19 nausea and vomiting, 13 out of 26 fatigue and anorexia, 23 out of 32 other treatment-associated toxicities, and 13 out of 16 information and care planning). Of the final indicators, 67 are potentially useful for inpatient and 81 for outpatient evaluation, and 26 address screening, 12 diagnostic evaluation, 20 management, and 21 follow-up. These quality indicators provide evidence-explicit tools for measuring processes critical to ensuring high-quality supportive cancer care. Research is needed to characterize adherence to recommended practices and to evaluate the use of these measures in quality improvement efforts.  相似文献   
104.
In the clinical setting, optical coherence tomography (OCT) is applicable for the non‐invasive diagnosis of skin cancer and may in particular be used for margin definition prior to excision. In this regard, OCT may improve the success rate of removing tumor lesions more effectively, preventing repetitive excision, which may subsequently result in smaller excisions. In this study, we have aimed to evaluate the applicability of OCT for in vivo presurgical margin assessment of non‐melanocytic skin tumors (NMSC) and to describe the feasibility of different scanning techniques. A total number of 18 patients planned for excision of lesions suspicious of NMSC were included in this study. Based on OCT, we defined the specific tumor margins on 19 lesions preoperatively using different scanning modalities. Sixty‐one margin points and five complete tumor margins were analysed on 18 patients with a total of 19 lesions including 63% basal cell carcinoma (BCC) (n = 12), 16% (n = 3) squamous cell carcinoma (SCC) and 21% of other types of skin tumors (n = 4) were classified. In 84% of the cases (n = 16), the OCT‐defined lateral margins correctly indicated complete removal of the tumor. The surgical margins chosen by the surgeon never fell below the OCT‐defined margin. Regarding the techniques of marginal definition, punctual tumor border scan in the perpendicular direction, with an extension of free‐run scans for unsure cases can hardly be recommended. This study shows that suspected NMSC can effectively be confirmed, and furthermore, resection margin can be minimized under OCT control without reducing the rate of complete removal.  相似文献   
105.
Abstract:  Free radicals are involved in pathophysiology of ischemia/reperfusion injury (IRI). Melatonin is a potent scavenger of reactive oxygen and nitrogen species. Thus, this study was designed to elucidate its effects in a model of rat kidney transplantation. Twenty Lewis rats were randomly divided into 2 groups (n = 10 animals each). Melatonin (50 mg/kg BW) dissolved in 5 mL milk was given to one group via gavage 2 hr before left donor nephrectomy. Controls were given the same volume of milk only. Kidney grafts were then transplanted into bilaterally nephrectomized syngeneic recipients after 24 hr of cold storage in Histidine–Tryptophan–Ketoglutarate solution. Both graft function and injury were assessed after transplantation through serum levels of blood urea nitrogen (BUN), creatinine, transaminases, and lactate dehydrogenase (LDH). Biopsies were taken to evaluate tubular damage, the enzymatic activity of superoxide dismutase (SOD) and lipid hydroperoxide (LPO), and the expression of NF-kBp65, inducible nitric oxide synthase (iNOS), caspase-3 as indices of oxidative stress, necrosis, and apoptosis, respectively. Melatonin improved survival ( P  < 0.01) while decreasing BUN, creatinine, transaminases, and LDH values up to 39–71% ( P  < 0.05). Melatonin significantly reduced the histological index for tubular damage, induced tissue enzymatic activity of SOD while reducing LPO. At the same time, melatonin down-regulated the expression of NF-kBp65, iNOS, and caspase-3. In conclusion, donor preconditioning with melatonin protected kidney donor grafts from IRI-induced renal dysfunction and tubular injury most likely through its anti-oxidative, anti-apoptotic and NF-kB inhibitory capacity.  相似文献   
106.
Histopathologic comparison of normal and hyperplastic condyles   总被引:1,自引:0,他引:1  
OBJECTIVE: The aim of this study was to compare normal and hyperplastic mandibular condyles using two different histopathologic staining techniques. STUDY DESIGN: Nine cases of condylar hyperplasia and 13 normal cases were studied after hematoxylin and eosin and silver staining. RESULTS: There was a significant difference between the two groups in the thickness of the hyperplastic cartilage layer of condylar soft tissue (P = 0.017). Also, the number of argyrophilic nucleolar organizer regions was significantly higher in the condylar hyperplasia case group (P = 0.0001). No significant differences could be demonstrated in cartilage island frequency, penetration depth, and distribution in the cancellous bone of condyles. CONCLUSION: The thickness of the hyperplastic cartilage layer appears significantly increased in condylar hyperplasia. In addition, argyrophilic nucleolar organizer region count may be useful in histopathological identification of condylar hyperplasia.  相似文献   
107.
108.
Background: Since we first described laparoscopic radiofrequency ablation (LRFA) of liver tumors, several reports have documented technical and safety aspects of this procedure. Little is known, however, about the long-term follow-up of such patients.Methods: From January 1996 to February 1999, we performed LRFA on 250 liver tumors in 66 patients. Triphasic spiral computed tomographic scanning was obtained preoperatively and at 1 week, and every 3 months postoperatively. Lesion diameter was measured in the x- and y-axes and the volume estimated; 181 lesions in 43 patients for whom computed tomographic scans available were included in the study. The tumor types were as follows: 64 metastatic adenocarcinomas, 79 neuroendocrine metastases, 27 other metastases, and 11 primary liver tumors.Results: One week postoperatively, the ablated zone was larger than the original tumor in 178 of 181 lesions, which suggests ablation of the tumor and a margin of normal liver tissue. A progressive decline in lesion size was seen in 156 (88%) of 178 lesions, followed for at least 3 months (mean, 13.9 months; range, 4.9–37.8 months), which suggests resorption of the ablated tissue. Fourteen definite local treatment failures were apparent by increase in size and change in computed tomographic scan appearance, and eight lesions were scored as failures because of multifocal recurrence that encroached on ablated foci (22 total recurrences). Predictors of failure include lack of increased lesion size at 1 week (2 of 3 such lesions failed), adenocarcinoma or sarcoma (18 of 22 failures; P < .05), larger tumors (failures, M < 18cm3 vs. successes, M < 7cm3; P < .005) and vascular invasion on laparoscopic ultrasonography. By size criteria, 17 of 22 failures were apparent by 6 months. Energy delivered per gram of tissue was not significantly different (P < .45).Conclusions: LRFA has a 12% local failure rate, with larger adenocarcinomas and sarcomas at greatest risk. Failures occur early in follow-up, with most occurring by 6 months. LRFA seems to be a safe and effective treatment technique for patients with primary and metastatic liver malignancies.Presented at the 52nd Annual Meeting of the Society of Surgical Oncology, Orlando, Florida, March 4–7, 1999  相似文献   
109.

Background  

Experimental studies indicate that gamma linolenic acid (GLA) and docosahexaenoic acid (DHA) may inhibit glioma cells growth but effects of oral consumption of these fatty acids on brain tumor fatty acid composition have not been determined in vivo.  相似文献   
110.
Arash Kimyai-Asadi  MD    Ming H. Jih  MD  PhD    Leonard H. Goldberg  MD 《Dermatologic surgery》2004,30(12P2):1526-1529
Background. There are a number of reports in the literature of patients developing thrombotic events after stopping medically necessary antiplatelet and antithrombotic agents.
Objective. The objective was to determine whether discontinuation of aspirin taken for primary prophylaxis contributes to the development of thrombotic complications in patients undergoing dermatologic surgery.
Methods. A case is reported and the literature is reviewed.
Results. We present the first reported case of a postoperative thrombotic event following dermatologic surgery in a patient withholding aspirin that was taken for primary prophylaxis.
Conclusion. We believe that the available data make it difficult to implicate aspirin discontinuation in the development of each thrombotic event, given the high baseline risk of thrombotic events in the Mohs surgery patient population and the low risk of developing such events when medications are withheld perioperatively.  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