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   8325篇
  免费   528篇
  国内免费   45篇
耳鼻咽喉   142篇
儿科学   358篇
妇产科学   207篇
基础医学   982篇
口腔科学   294篇
临床医学   740篇
内科学   1823篇
皮肤病学   129篇
神经病学   471篇
特种医学   184篇
外国民族医学   3篇
外科学   1258篇
综合类   414篇
一般理论   7篇
预防医学   617篇
眼科学   233篇
药学   615篇
中国医学   61篇
肿瘤学   360篇
  2023年   107篇
  2022年   262篇
  2021年   527篇
  2020年   260篇
  2019年   285篇
  2018年   355篇
  2017年   241篇
  2016年   279篇
  2015年   343篇
  2014年   426篇
  2013年   424篇
  2012年   609篇
  2011年   596篇
  2010年   361篇
  2009年   307篇
  2008年   444篇
  2007年   461篇
  2006年   427篇
  2005年   399篇
  2004年   337篇
  2003年   288篇
  2002年   252篇
  2001年   118篇
  2000年   103篇
  1999年   92篇
  1998年   41篇
  1997年   29篇
  1996年   31篇
  1995年   24篇
  1994年   27篇
  1993年   21篇
  1992年   43篇
  1991年   43篇
  1990年   36篇
  1989年   30篇
  1988年   28篇
  1987年   32篇
  1986年   25篇
  1985年   19篇
  1984年   11篇
  1983年   15篇
  1982年   12篇
  1981年   16篇
  1980年   8篇
  1979年   18篇
  1977年   10篇
  1976年   10篇
  1974年   8篇
  1972年   8篇
  1970年   8篇
排序方式: 共有8898条查询结果,搜索用时 734 毫秒
61.
Hand surgery is a unique field that incorporates multiple specialties, aiming to provide the patient with a best possible functional and aesthetic results. Hand surgeons deal with different pathologies that require skills in several aspects of surgery. The field of hand surgery has evolved significantly over the past decades across the globe. This specialty has also been evolving in Saudi Arabia over the past 25 years. Some of the services offered to patients include specialized centers for brachial plexus, peripheral nerve, and pediatric hand surgery as well as centers for work-related hand injuries. There has also been significant contribution to the hand surgery literature from the hand surgeons working in Saudi Arabia, with hundreds of papers published in journals pertaining to hand surgery, orthopedic surgery, and plastic surgery, as well as the publication of several novel mutations causing congenital hand defects in journals concerned with genetics. The recent approval of a hand and microsurgery fellowship program in Saudi Arabia will also help boost this field in the country and the region.  相似文献   
62.
63.
Breast fat necrosis (BFN) is usually a benign inflammatory response to breast trauma. However, an extremely rare cause of fat necrosis is calciphylaxis, a calcification of small- and medium-sized arteries causing thrombosis and ischemia. It is classified into (A) uremic (B) nonuremic-induced calciphylaxis. Calciphylaxis has been reported to be encountered in different parts of the body. However, to the best of our knowledge there is only one case in the English literature of BFN 2ry to warfarin-induced calciphylaxis. We report a 65-year-old female, known case of atrial fibrillation on warfarin, presented with a left breast mass of 4-month duration. The mass was painful and progressively enlarging. Examination of the left breast showed 7 × 4 cm mass, spanning from 10-2 o'clock, free from surrounding structures, with preserved overlying skin. However, the mass was not visualized on mammogram. Ultrasound showed a left breast lobulated hypoechoic mass containing a hyperechoic component. Biopsy showed fat necrosis. After 1 month, she presented with ulceration of the overlying skin. After wide local excision, histopathology demonstrated a calciphylaxis-induced fat necrosis. Considering the patient's background, the diagnosis was BFN secondary to warfarin-induced calciphylaxis. Hence, the warfarin was shifted to Rivaroxaban, 6 months follow-up showed no evidence of recurrence. In conclusion, the rarity of nonuremic calciphylaxis is reflected on the delay of diagnosis in some of the reported cases and the lack of grading system used to guide the management of such difficult wounds. However, keeping a high index of suspicion is important whenever such wounds are encountered with presence of risk factors other than end-stage kidney disease.  相似文献   
64.
Background:Urosepsis is a recognized complication of transrectal ultrasound-guided prostate biopsy (TRUS-Bx). Pre-biopsy rectal swabs have been used to identify patients with microorganisms in the rectal flora resistant to the conventionally used empirical prophylaxis. The transperineal route of biopsy (TP-Bx) has a lower complication risk but comes at an increased cost.Materials and methods:Retrospective cohort study including patients undergoing prostate biopsies between October/2015 and April/2018. The intervention cohort, a rectal swab was performed, the result of which dictated the biopsy route; TRUS-Bx against TP-Bx. TP-Bx for patients with fluoroquinolone resistance or extended-spectrum β-lactamase. The control cohort underwent TRUS without a rectal swab receiving empirical antibiotics—oral ciprofloxacin and intravenous gentamicin.Results:Total 1000 patients were included in which 500 underwent a swab, 14 (2.8%) developed post-TRUS biopsy infective complications with 3 having positive bacteremia (0.6%); 500 had no swab, 47 (9.4%) developed post-TRUS biopsy infective complications with 22 (4.4%, p < 0.05) having positive bacteremia. Three patients (0.6%) of patients who underwent swab developed urinary tract infection symptoms whilst 12 (2.4%) had urinary tract infection in the control group. In those patients that underwent a swab, 14 required hospitalization with mean length of stay of 2.5 days versus 43 patients of the control with 3.6 days. Cost analysis concluded savings of this strategy was £18,711.Conclusions:We have demonstrated a protocol that reserves template biopsies for higher risk patients and can significantly reduce sepsis and other infectious complication rates whilst also proving to be a cost-efficient strategy. We recommend that units not utilizing rectal swabs to uncover the fluoroquinolone resistance rate by introducing them. We advocate units that already utilize rectal swabs, to introduce transperineal biopsy for their higher risk patients.  相似文献   
65.
Preoperative placement of ureteral catheters has been recommended for prevention of ureteral injuries. During a three-year period, prophylactic ureteral catheters were inserted selectively in 59 patients undergoing colorectal surgery in whom a difficult dissection was anticipated. Three patients developed reflux anuria after the use of prophylactic ureteral catheters. The safety of these catheters is questioned, and the diagnoses and methods of preventing ureteral injuries are discussed.  相似文献   
66.
67.
Retinoid inhibition of breast carcinoma growth correlates with the estrogen receptor (ER) positivity and elevated retinoic acid nuclear receptor (RARalpha) mRNA levels. We therefore examined retinoid nuclear receptor mRNA levels in patient breast carcinoma biopsy specimens to determine if such a correlation exists between ER positivity and RARalpha mRNA levels. We have now shown that RARalpha mRNA levels are significantly higher in ER positive samples. RARgamma mRNA is expressed at relatively high levels in a majority of the tumor samples independent of the ER-status while RARbeta mRNA was expressed at low levels in only one tumor sample. We also found high RXRalpha mRNA levels in all of the tumor samples examined while RXRgamma mRNA could not be detected. Our study demonstrates that RARalpha mRNA levels are either low or absent in ER-negative patient samples and that RARalpha levels may serve as a potential marker to determine patient responsiveness to RA therapy.  相似文献   
68.
Ultrasonography has been proposed as a screening method for blunt abdominal trauma, but its specific role in comparison with other diagnostic modalities has yet to be defined. The aim of the present retrospective study was to compare the results of ultrasonography and CT of the abdomen in blunt trauma in a district general hospital. The hospital records of 25 patients who were admitted with blunt abdominal trauma to Southland Hospital, Invercargill, New Zealand, between January 1991 and November 1996 and who had both ultrasound and CT of the abdomen within 48 h of admission were reviewed. Ultrasound missed seven lesions in seven patients (7/25, 28%) compared with CT. Three of these were intestinal lesions that needed laparotomy. Ultrasound had a usefulness index of 1, 0.76, 0.72, 0.69 and 0, respectively, for detecting lesions of the kidneys, free intraperitoneal fluid, the liver, the spleen, and intestines. Although ultrasound can be used as an initial screening method for blunt abdominal trauma, CT is still the imaging modality of choice for detecting intra-abdominal lesions for stable patients in a district general hospital.  相似文献   
69.
This paper presents an expansile lesion of the temporal bone, in a 14-year-old boy, that was initially diagnosed as intra-osseous meningioma from CT appearance. At histopathology a final diagnosis of giant cell tumour was made. A brief review of the literature is presented for this rare case.  相似文献   
70.
N A Sheikh  P Rajananthanan  G S Attard  W J Morrow 《Vaccine》1999,17(23-24):2974-2982
Presentation of peptide on MHC class I molecules is essential to elicit cytolytic T cell (CTL) activity. Such peptides are a result of the cytosolic, or class I, antigen processing pathway. Due to the segregation of the class I and the exogenous processing pathway, soluble protein cannot enter the class I pathway and is thus incapable of inducing CTL. However careful formulation with adjuvants can overcome this obstacle. In this study we evaluated the capacity of two novel amphiphilic adjuvants, better termed delivery vehicles, to elicit CTL activity in a C57Bl/6 murine model with ovalbumin (OVA) as an antigen. Incomplete Freund's adjuvant and aluminium hydroxide (Alhydrogel) were used as reference adjuvants. In addition the oil-in-water emulsion Provax was used throughout as a positive control adjuvant. Both amphiphile preparations were capable of eliciting potent CTL activity after administration of one immunizing dose of ovalbumin. CTL were CD8+ restricted as assessed by in vitro depletion of CD8+ and CD4+ T cells. CTL activity was also MHC-restricted as well as specific for the H-2Kb OVA motif SIINFEKL.  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