全文获取类型
收费全文 | 2947篇 |
免费 | 183篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 101篇 |
儿科学 | 195篇 |
妇产科学 | 39篇 |
基础医学 | 348篇 |
口腔科学 | 72篇 |
临床医学 | 240篇 |
内科学 | 712篇 |
皮肤病学 | 85篇 |
神经病学 | 130篇 |
特种医学 | 122篇 |
外科学 | 282篇 |
综合类 | 59篇 |
一般理论 | 1篇 |
预防医学 | 235篇 |
眼科学 | 177篇 |
药学 | 203篇 |
中国医学 | 12篇 |
肿瘤学 | 126篇 |
出版年
2021年 | 42篇 |
2020年 | 43篇 |
2019年 | 52篇 |
2018年 | 71篇 |
2017年 | 38篇 |
2016年 | 55篇 |
2015年 | 57篇 |
2014年 | 82篇 |
2013年 | 105篇 |
2012年 | 186篇 |
2011年 | 161篇 |
2010年 | 96篇 |
2009年 | 80篇 |
2008年 | 154篇 |
2007年 | 159篇 |
2006年 | 157篇 |
2005年 | 120篇 |
2004年 | 116篇 |
2003年 | 110篇 |
2002年 | 97篇 |
2001年 | 65篇 |
2000年 | 60篇 |
1999年 | 61篇 |
1998年 | 30篇 |
1997年 | 28篇 |
1996年 | 27篇 |
1995年 | 17篇 |
1992年 | 45篇 |
1991年 | 52篇 |
1990年 | 36篇 |
1989年 | 37篇 |
1988年 | 48篇 |
1987年 | 36篇 |
1986年 | 35篇 |
1985年 | 50篇 |
1984年 | 43篇 |
1983年 | 30篇 |
1982年 | 23篇 |
1980年 | 21篇 |
1979年 | 31篇 |
1978年 | 16篇 |
1977年 | 18篇 |
1976年 | 16篇 |
1974年 | 24篇 |
1973年 | 22篇 |
1972年 | 17篇 |
1971年 | 24篇 |
1970年 | 19篇 |
1967年 | 16篇 |
1966年 | 16篇 |
排序方式: 共有3139条查询结果,搜索用时 15 毫秒
21.
Otospongiosis-like lesions were induced in rats by immunizing them with type II collagen. After seven months' immunization, the rats were killed and processed for histologic study. We found otospongiotic lesions in the bony cochlea, vestibule, semicircular canal, and in the regions near the oval window and round window. The spongiotic lesions in the otic capsules were similar to human otospongiosis and were characterized by the following types of microscopic appearances. 1) The classic type showed enlarged vascular spaces with congestion, macrophages, fibroblasts, and sometimes osteoclasts. 2) The fibrotic type showed vascular spaces filled with fibrous tissues. 3) The osteoporotic type had a porous appearance and was devoid of content. 4) The sclerotic type showed bone spaces partially or entirely being replaced by new bone with blue mantles and a mosaic appearance. Some spongiotic lesions showed a mixture of the above types. The findings suggest that this animal model may provide important information to help understand the process of human otosclerosis. 相似文献
22.
23.
Hiromichi Ito Michael Abramson Kaori Ito Edward Swanson Nancy Cho Daniel T. Ruan Richard S. Swanson Edward E. Whang 《Journal of gastrointestinal surgery》2010,14(5):891-898
Background
The aims of this study were to evaluate contemporary outcomes associated with the surgical management of pancreatic neuroendocrine tumors (PNETs) and to assess the prognostic value of the World Health Organization (WHO) classification and TNM staging for PNETs. 相似文献24.
Meenakshi Sindhu Vandana Saini Sakshi Piplani A. Kumar 《Indian journal of pharmaceutical sciences》2013,75(1):23-30
The structure-function correlation of membrane proteins have been a difficult task, particularly in context to transient protein complexes. The molecular simulation of ternary complex of Rab7::REP1::GGTase-II was carried out to understand the basic structural events occurring during the prenylation event of Rab proteins, using the software YASARA. The study suggested that the C-terminus of Rab7 has to be in completely extended conformation during prenylation to reach the active site of RabGGTase-II. Also, attempt was made to find putative drug binding sites on the ternary complex of Rab7::REP1::GGTase-II using Q-SiteFinder programme. The comprehensive consensus probe generated by the program revealed a total of 10 major pockets as putative drug binding sites on Rab7::REP:: GGTase-II ternary complex. These pockets were found on REP protein and GGTase protein subunits. The Rab7 was found to be devoid of any putative drug binding sites in the ternary complex. The phylogenetic analysis of 60 Rab proteins of human was carried out using PHYLIP and study indicated the close phylogenetic relationship between Rab7 and Rab9 proteins of human and hence with further in silico study, the present observations can be extrapolated to Rab9 proteins. The study paves a good platform for further experimental verifications of the findings and other in silico studies like identifying the potential drug targets by searching the putative drug binding sites, generating pharmacophoric pattern, searching or constructing suitable ligand and docking studies. 相似文献
25.
26.
27.
Kallol Ray Chaudhuri Pablo Martinez-Martin Anthony H V Schapira Fabrizio Stocchi Kapil Sethi Per Odin Richard G Brown William Koller Paolo Barone Graeme MacPhee Linda Kelly Martin Rabey Doug MacMahon Sue Thomas William Ondo David Rye Alison Forbes Susanne Tluk Vandana Dhawan Annette Bowron Adrian J Williams Charles W Olanow 《Movement disorders》2006,21(7):916-923
Nonmotor symptoms (NMS) of Parkinson's disease (PD) are not well recognized in clinical practice, either in primary or in secondary care, and are frequently missed during routine consultations. There is no single instrument (questionnaire or scale) that enables a comprehensive assessment of the range of NMS in PD both for the identification of problems and for the measurement of outcome. Against this background, a multidisciplinary group of experts, including patient group representatives, has developed an NMS screening questionnaire comprising 30 items. This instrument does not provide an overall score of disability and is not a graded or rating instrument. Instead, it is a screening tool designed to draw attention to the presence of NMS and initiate further investigation. In this article, we present the results from an international pilot study assessing feasibility, validity, and acceptability of a nonmotor questionnaire (NMSQuest). Data from 123 PD patients and 96 controls were analyzed. NMS were highly significantly more prevalent in PD compared to controls (PD NMS, median = 9.0, mean = 9.5 vs. control NMS, median = 5.5, mean = 4.0; Mann-Whitney, Kruskal-Wallis, and t test, P < 0.0001), with PD patients reporting at least 10 different NMS on average per patient. In PD, NMS were highly significantly more prevalent across all disease stages and the number of symptoms correlated significantly with advancing disease and duration of disease. Furthermore, frequently, problems such as diplopia, dribbling, apathy, blues, taste and smell problems were never previously disclosed to the health professionals. 相似文献
28.
BACKGROUND: The effectiveness of prophylactic antibiotics in the prevention of surgical site infection (SSI) after elective colorectal surgery is dependent on many factors, including the body mass index (BMI) of the patient. In this study, the association of BMI and type of antibiotic prophylaxis with SSI was evaluated in patients undergoing elective colorectal surgery. METHOD: A post-hoc analysis was performed using data obtained from a multicenter randomized, double-blind study of 1,002 patients undergoing elective colorectal surgery who received prophylactic administration of ertapenem (1 g) or cefotetan (2 g). Among 650 evaluable patients, the effect of BMI and type of antibiotic prophylaxis on SSI rates was assessed four weeks after surgery. Mechanical bowel preparation was standardized, and no patient received oral antibiotics; intravenous antibiotics were not repeated during or after surgery. RESULTS: The majority of patients had a BMI between 18.5 and 39.9 kg/m2. Regardless of the type of prophylaxis, SSI rates were significantly higher in patients with a BMI > or = 30 kg/m2 than in those with a BMI < 30 kg/m2. However, failure, defined as SSI, was significantly less common after ertapenem than after cefotetan prophylaxis at both BMI < 30 kg/m2 (12.7% vs. 26.4%, respectively; difference -13.7; 95% confidence interval [CI] -21.0, -6.5) and BMI > or = 30 kg/m2 (26.7% vs. 41.9%, respectively; difference -15.3; 95% CI -28.2, -2.0). The most prevalent type of SSI was superficial incisional infection, which was more common with both treatments in patients with a BMI > or = 30 kg/m2; however, the incidence of superficial SSI was lower after ertapenem than cefotetan prophylaxis. CONCLUSION: In patients undergoing elective colorectal surgery, the incidence of SSI, specifically superficial incisional SSI, was higher in patients with a BMI > or = 30 kg/m2, regardless of the prophylactic antibiotic given. Ertapenem prophylaxis was more effective than cefotetan in the prevention of SSI at any BMI. 相似文献
29.
Glasoe W Pena F Phadke V Ludewig PM 《Foot & ankle international / American Orthopaedic Foot and Ankle Society [and] Swiss Foot and Ankle Society》2008,29(6):647-655
BACKGROUND: This study investigated the association of arch height combined with first metatarsal joint axis vertical (V) orientation to the size of the 1-2 intermetatarsal angle (IMA) and first metatarsal adduction/abduction position simulating foot postures during gait, kinematics commonly affected by bunion. MATERIALS AND METHODS: Nine cadaver specimens were mounted in a loading frame. Measures of arch height ratio and IMA were made. With the foot placed in positions seen during normal gait cycle an electromagnetic device measured displacement of the relative angle of rotations between the first metatarsal and navicular, and helical axis (HA) parameters. Canonical correlation analysis assessed the relationship among the variables. RESULTS: A negative relationship (r = -0.73) was found between arch height and first metatarsal HA V-orientation. When considered as combined variables, arch height and metatarsal HA V-orientation accounted for 69% of the variance of IMA and change in first metatarsal adduction/abduction position. CONCLUSION: Orientation of the first metatarsal joint axis was highly variable between specimens but correlated with arch height. The conjoined factors of arch height and first metatarsal HA V-orientation accounted for most of the variance of IMA and change in first metatarsal adduction/abduction position during the sequence of foot position during simulated gait. CLINICAL RELEVANCE: These findings suggest that orthotic arch support could reorient the metatarsal joint axis out-of-vertical and in effect, limit the first metatarsal from displacing into an adducted bunion deformity. These findings could help to explain the pathogenesis of bunions. 相似文献
30.
BACKGROUND: Complicated intra-abdominal infections are a common problem in surgical practice. This study compared the effectiveness of ertapenem (1 g qd) and piperacillin/tazobactam (3.375 g q6h) in the treatment of these infections. METHODS: This was a multicenter, double-blinded, randomized study conducted in patients with complicated intra-abdominal infections. Of the 535 patients screened, 500 were stratified on the basis of disease severity (Acute Physiology and Chronic Health Evaluation [APACHE] II score < or =10 or >10), then randomized (1:1) to 4-14 days of treatment with one of the regimens and six weeks of followup. Nearly all patients (N = 494) were treated. The primary endpoint was the proportion of microbiologically evaluable patients with a favorable clinical response (cure) at two weeks. Non-inferiority of ertapenem was based on a difference in response rate of <15 percentage points compared with piperacillin/tazobactam (lower bound of the 95% CI > -15). RESULTS: Of the 494 treated patients, 231 were microbiologically evaluable, with 123 and 108 patients in the ertapenem and piperacillin/tazobactam groups, respectively. Statistically similar cure rates were observed in the ertapenem (82.1%) and piperacillin/tazobactam (81.7%) groups (difference 0.3 [95% CI: -9.6, 10.5]). The pathogens isolated most frequently were Escherichia coli, Bacteroides fragilis, and Bacteroides thetaiotamicron, typical isolates associated with intra-abdominal infections. There were no statistical differences between the groups in serious drug-related clinical adverse events, drug-related clinical adverse experiences leading to study discontinuation, or mortality. CONCLUSIONS: Ertapenem was non-inferior to piperacillin/tazobactam in the cure of intra-abdominal infections caused by susceptible pathogens. Both study drugs generally were well tolerated. 相似文献