全文获取类型
收费全文 | 4501篇 |
免费 | 242篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 24篇 |
儿科学 | 292篇 |
妇产科学 | 138篇 |
基础医学 | 463篇 |
口腔科学 | 104篇 |
临床医学 | 331篇 |
内科学 | 965篇 |
皮肤病学 | 93篇 |
神经病学 | 231篇 |
特种医学 | 120篇 |
外科学 | 707篇 |
综合类 | 92篇 |
一般理论 | 2篇 |
预防医学 | 199篇 |
眼科学 | 401篇 |
药学 | 391篇 |
中国医学 | 18篇 |
肿瘤学 | 184篇 |
出版年
2023年 | 36篇 |
2022年 | 77篇 |
2021年 | 148篇 |
2020年 | 76篇 |
2019年 | 92篇 |
2018年 | 156篇 |
2017年 | 100篇 |
2016年 | 103篇 |
2015年 | 122篇 |
2014年 | 181篇 |
2013年 | 215篇 |
2012年 | 359篇 |
2011年 | 352篇 |
2010年 | 189篇 |
2009年 | 176篇 |
2008年 | 269篇 |
2007年 | 218篇 |
2006年 | 203篇 |
2005年 | 230篇 |
2004年 | 207篇 |
2003年 | 131篇 |
2002年 | 117篇 |
2001年 | 86篇 |
2000年 | 72篇 |
1999年 | 67篇 |
1998年 | 29篇 |
1997年 | 16篇 |
1996年 | 24篇 |
1994年 | 14篇 |
1993年 | 20篇 |
1992年 | 44篇 |
1991年 | 50篇 |
1990年 | 40篇 |
1989年 | 41篇 |
1988年 | 47篇 |
1987年 | 36篇 |
1986年 | 35篇 |
1985年 | 17篇 |
1984年 | 23篇 |
1983年 | 16篇 |
1982年 | 15篇 |
1981年 | 19篇 |
1979年 | 30篇 |
1977年 | 15篇 |
1975年 | 14篇 |
1974年 | 17篇 |
1973年 | 28篇 |
1972年 | 35篇 |
1971年 | 16篇 |
1970年 | 27篇 |
排序方式: 共有4755条查询结果,搜索用时 15 毫秒
81.
Potter James Sat Parmar Khalid Hussain Prav Praveen 《The British journal of oral & maxillofacial surgery》2021,59(1):82-85
INTRODUCTIONTracheal stenosis is a late and usually non-life threatening complication of surgical and percutaneous tracheostomies (PDT) as well as delayed endotracheal extubation.METHODSWe undertook a retrospective review of all patients who underwent a surgical tracheostomy over a 10 year period. Patients were included in the study if they had CT or MRI imaging of the tracheostomy site both pre-operatively and six or more weeks post operatively. Patients whose imaging was not available were excluded (n = 3) as were those patients who still had a tracheostomy in situ (n = 8). In total 91 patients were included in the study. In the same period 1170 surgical tracheostomies were performed by the maxillofacial surgeons. The images were analysed by a radiologist and the degree of stenosis reported.RESULTSAll 91 patients underwent a tracheostomy with a window. 83 patients did not demonstrate any stenosis. Looking at the remaining 8 patients with stenosis: 6 patients had stenosis of less than 25%, 1 patient had stenosis between 25-50% and 1 patient had stenosis greater than 50%. Both patients with stenosis greater than 25% had more than one surgical tracheostomy.CONCULSIONWe have shown that the risk of stenosis is 8.8%, lower than often quoted in literature, and when it occurs it is likely to be symptomatic only in severe stenosis. Our main risk of stenosis was repeat surgical tracheostomies which also seems to be linked to a greater degree of stenosis. 相似文献
82.
83.
84.
Rabin Koirala Naimish Mehta Vibha Varma Sorabh Kapoor Vinay Kumaran Samiran Nundy 《The Indian journal of surgery》2015,77(3):195-199
A proportion of the operations performed in a surgical gastroenterology department are unplanned repeat laparotomies for complications of the original procedure. We examined why, in our department, these ‘redo’ laparotomies were performed and what was their outcome. We retrospectively analyzed 6530 patients operated between September 1996 - December 2010, of these 257 redo laparotomies were performed in 193(2.5 %) patients. There were 138 males and 55 females who had a mean age of 42 years (range 7–68 years). Eighty one (42 %) of the index surgeries were elective and 112 (58 %) performed in the emergency situation. Pancreas was the commonest organ for the index operation {50 (25.9 %)}, followed by the colon and rectum {45 (23.3 %)} and the small bowel {36 (18.7 %)}. Postoperative bleeding was the most common cause for re-exploration 66 (34.2 %) followed by an abscess or fluid collection that required surgical drainage 57 (29.6 %). The mortality rate after redo laparotomies was 33.2 % with sepsis and multi-organ failure being the commonest cause of death. Urgent redo-laparotomies that are performed following complicated abdominal operations have a high mortality rate. Postoperative bleeding, intrabdominal abscess and peritonitis are the commonest cause for redo-laparotomy. Multiple redolaparotomies and associated co-morbid conditions are significant predictors of mortality. 相似文献
85.
Shirish S. Nandedkar Ekta Patidar Dhiraj B. Gada Kamal Malukani Kavita Munjal Amit Varma 《Journal of obstetrics and gynaecology of India》2015,65(5):328-334
Background
Endometrium is the most sensitive indicator of ovarian function and endometrial biopsy is one of the most important investigations in infertility. The current study was carried out to investigate the histomorphological patterns of endometrium in infertile women and to compare the results with other similar studies.Materials and Methods
A cross-sectional study on 2,080 infertile women was carried out to find the incidence of various histomorphological patterns in hematoxylin-eosin stained sections of endometrium and compare them with other Indian studies.Results
In the current study majority of cases (88.50 %) were of primary infertility; the highest number of cases was in the age group of 21–30 years and the oldest patient was of 50 years age. The various abnormalities observed were anovulatory endometrium (15.75 %), inadequate proliferative (1.90 %), inadequate secretory (9.52 %), glandulo-stromal disparity (GSD) (4.21 %), hyperplasia (1.10 %), and endometritis (1.63 %). In 3.0 % cases menstrual cycle history was not available and curettage was done at inappropriate period of the cycle in 11.63 %. Comparison with other studies revealed the results matching with some and differing with others.Conclusion
In the current study, anovulatory endometrium and luteal phase defect are the major causes of infertility, and tuberculous endometritis, non-specific endometritis and GSD are minor contributing factors. These are treatable causes. Premenstrual endometrial biopsy, if accompanied by information of menstrual cycle and date of biopsy, can be a very reliable diagnostic tool for hormonal dysfunction and intrinsic endometrial factors in infertility. 相似文献86.
87.
Clinical utility of EUS-guided fine-needle aspiration of mediastinal masses in the absence of known pulmonary malignancy 总被引:2,自引:0,他引:2
Devereaux BM Leblanc JK Yousif E Kesler K Brooks J Mathur P Sandler A Chappo J Lehman GA Sherman S Gress F Ciaccia D 《Gastrointestinal endoscopy》2002,56(3):397-401
BACKGROUND: Mediastinal masses represent a diagnostic challenge because of their proximity to numerous critical structures, difficulty of access for tissue sampling, and myriad potential pathologic etiologies. A large, single-center experience with EUS-guided fine-needle aspiration (EUS-FNA) in the diagnosis of non-lung cancer-related mediastinal masses is presented. METHODS: An EUS database was reviewed and all cases of mediastinal mass or lymphadenopathy encountered between 1994 and 1999 were included. Final diagnoses were determined by EUS-FNA cytology and clinical follow-up. RESULTS: Forty-nine patients were identified (27 women, 22 men; mean age 58.1 years, range 30-89 years). A malignant process was diagnosed in 22 cases (45%) and a benign process in 24 (49%). The EUS-FNA specimen was nondiagnostic in 3 cases (6%). An accurate diagnosis was made in 46 of the 49 patients (94%). No complication was noted. CONCLUSIONS: EUS-FNA is a minimally invasive technique that facilitates detection and tissue sampling of mediastinal masses. It is a safe procedure that can be performed with the patient under conscious sedation in an outpatient setting. 相似文献
88.
Sattar Alshryda James M. Mason Praveen Sarda T. Lou Martin Stanley Junjie Wu Anthony Unsworth 《Journal of orthopaedics and traumatology》2015,16(1):27-34
Background
Tranexamic acid (TXA) has been successfully used to reduce bleeding in joint replacement. Recently local TXA has been advocated to reduce blood loss in total knee or hip replacement; however, this raised concerns about potential adverse effects of TXA upon the artificial joint replacement.Materials and methods
In this biomechanical study we compared the effects of TXA and saline upon the following biomechanical properties of artificial joint materials—(1) tensile properties (ultimate strength, stiffness and Young’s modulus), (2) the wear rate using a multi-directional pin-on-plate machine, and (3) the surface topography of pins and plates before and after wear rate testing.Results
There were no significant differences in tensile strength, wear rates or surface topography of either ultra-high-molecular-weight polyethylene pins or cobalt chromium molybdenum metal plates between specimens soaked in TXA and specimens soaked in saline.Conclusion
Biomechanical testing shows that there are no biomechanical adverse affects on the properties of common artificial joint materials from using topical TXA.Level of evidence
V 相似文献89.
Sekar U Srikanth P Kindo AJ Babu VP Ramasubramanian V 《The Journal of communicable diseases》2003,35(3):162-169
Multidrug resistance among Salmonella typhi is well known. Reports of treatment failure in enteric fever with Ciprofloxacin made us undertake this study to determine the antibiotic susceptibility pattern of S. typhi and S. paratyphi A isolated from typhoid bacteremia cases, by disc diffusion and MIC by broth dilution method. A total of 50 strains were tested, 48 of Salmonella typhi and 2 of S. paratyphi A. The disc diffusion method was done using ampicillin, chloramphenicol, cotrimoxazole, tetracycline, ciprofloxacin, ofloxacin, cefuroxime and ceftriaxone as antibiotics. The MIC was performed using ciproloxacin, ofloxacin and ceftriaxone based on standard procedure. ACCOT resistance as determined by disc diffusion method was seen in 68% of isolates. All the strains remained susceptible to flouroquinolones cephalosporins and aminoglycosides. The MIC of ciprofloxacin, ofloxacin and ceftriaxone were in the recommended range of susceptibility as given by NCCLS, 14 (28%) strains had MIC of ciprofloxacin greater than 0.5 ug/ml with 4 strains having an MIC of 1.56 ug/ml; 25 (50%) strains had MIC of ofloxacin greater than 0.5 ug/ml and 20 (40%) strains had MIC of ceftriaxone greater than 0.5 ug/ml. The high levels of MIC of ciprofloxacin may account for treatment failure cases. The rising levels of MIC of ofloxacin and ceftriaxone in S. typhi and S. paratyphi is also of concern. We document here the emergence of high levels of MIC not only to ciprofloxacin, but also ofloxacin and ceftriaxone in S. typhi and S. paratyphi A. We recommend that MIC levels of ofloxacin and ceftriaxone should be monitored along with ciprofloxacin in treatment failure cases of enteric fever. 相似文献
90.
Pulkit Rastogi Prashant Sharma Neelam Varma Dmitry Sukhachev Naveen Kaushal Ishwar Bihana Man Updesh Singh Sachdeva Shano Naseem Pankaj Malhotra 《Indian journal of hematology & blood transfusion》2018,34(4):623-631
Automated blood counts revealing lymphocytosis necessitate smear reviews. Even expert morphological evaluation may however, fail to differentiate a benign-versus-malignant etiology without further testing. Automated analyser-derived quantitative data on leukocyte cell populations remain undertested for distinguishing such etiologies. Instrument manufacturers claim that if successful, they may be used to generate software flags that help under-resourced laboratories better triage hemogram specimens requiring further testing. We tested the diagnostic accuracy of volume-conductivity-scatter (VCS) indices together with complete blood count (CBC) parameters in such scenarios. We compared LH780-derived (Beckman Coulter, FL, USA) CBC + VCS parameters from patients with clonal lymphoproliferations (n = 42, including 30 chronic lymphocytic leukemia cases) versus 83 controls with absolute or relative lymphocytosis (derivation cohort). Diagnostic performances of 11 logistic regression equations derived were subsequently evaluated on two specific validation cohorts (n = 130 and n = 1465). Clonal lymphocytoses showed significantly lower hemoglobin and higher leukocyte counts but similar lymphocyte percentages (LY %) vis-à-vis controls. The most significant, albeit overlapping predictor of clonality was the absolute lymphocyte count, LY# (47.8 ± 48.4 × 109/L vs. 2.9 ± 1.4 × 109/L in clonal vs. benign cases). In eleven logistic regression equations constructed using four combinatorial approaches, only the models with LY# (highest sensitivity/specificity of 99.3%/100%) and the lymphocytic VCS parameters alone (highest sensitivity/specificity of 76.2%/90.2%) performed consistently in both validation cohorts. Lymphocytic VCS parameters were moderately successful in distinguishing benign-versus-malignant lymphocytes. Other approaches of CBC-plus-VCS parameters did not sustain their initial excellent performances in the validation cohorts, highlighting a need for careful appraisal and better standardization of automated cellular analysis technologies. 相似文献