全文获取类型
收费全文 | 5320篇 |
免费 | 423篇 |
国内免费 | 53篇 |
专业分类
耳鼻咽喉 | 50篇 |
儿科学 | 156篇 |
妇产科学 | 110篇 |
基础医学 | 752篇 |
口腔科学 | 103篇 |
临床医学 | 500篇 |
内科学 | 1011篇 |
皮肤病学 | 42篇 |
神经病学 | 453篇 |
特种医学 | 410篇 |
外科学 | 963篇 |
综合类 | 107篇 |
一般理论 | 2篇 |
预防医学 | 426篇 |
眼科学 | 46篇 |
药学 | 277篇 |
中国医学 | 6篇 |
肿瘤学 | 382篇 |
出版年
2023年 | 24篇 |
2022年 | 51篇 |
2021年 | 102篇 |
2020年 | 62篇 |
2019年 | 109篇 |
2018年 | 124篇 |
2017年 | 81篇 |
2016年 | 102篇 |
2015年 | 113篇 |
2014年 | 152篇 |
2013年 | 236篇 |
2012年 | 319篇 |
2011年 | 320篇 |
2010年 | 173篇 |
2009年 | 170篇 |
2008年 | 258篇 |
2007年 | 294篇 |
2006年 | 211篇 |
2005年 | 212篇 |
2004年 | 189篇 |
2003年 | 150篇 |
2002年 | 168篇 |
2001年 | 139篇 |
2000年 | 134篇 |
1999年 | 130篇 |
1998年 | 73篇 |
1997年 | 77篇 |
1996年 | 70篇 |
1995年 | 81篇 |
1994年 | 83篇 |
1993年 | 48篇 |
1992年 | 102篇 |
1991年 | 88篇 |
1990年 | 119篇 |
1989年 | 126篇 |
1988年 | 107篇 |
1987年 | 104篇 |
1986年 | 99篇 |
1985年 | 79篇 |
1984年 | 66篇 |
1983年 | 49篇 |
1982年 | 34篇 |
1981年 | 33篇 |
1980年 | 20篇 |
1979年 | 41篇 |
1978年 | 29篇 |
1977年 | 23篇 |
1976年 | 24篇 |
1975年 | 21篇 |
1974年 | 30篇 |
排序方式: 共有5796条查询结果,搜索用时 15 毫秒
61.
Borna disease virus-induced hippocampal dentate gyrus damage is associated with spatial learning and memory deficits 总被引:5,自引:0,他引:5
Rubin SA Sylves P Vogel M Pletnikov M Moran TH Schwartz GJ Carbone KM 《Brain research bulletin》1999,48(1):475-30
In neonatally inoculated rats, Borna disease virus (BDV) leads to a persistent infection of the brain in the absence of an inflammatory response and is associated with neuroanatomic, developmental, physiologic, and behavioral abnormalities. One of the most dramatic sites of BDV-associated damage in the neonatal rat brain is the dentate gyrus, a neuroanatomic region believed to play a major role in spatial learning and memory. The absence of a generalized inflammatory response to neonatal BDV infection permits direct effects of viral damage to the dentate gyrus to be examined. In this report, neonatally BDV-infected rats at various stages of dentate gyrus degeneration were evaluated in the Morris water maze, a swimming test that assesses the rats' capacity to navigate by visual cues. Our data demonstrate progressive spatial learning and memory deficits in BDV-infected rats that coincided with a gradual decline in the estimated hippocampal dentate gyrus neuron density. 相似文献
62.
J M Moran D W Burke J M Loeb A J Roberts J H Sanders L L Michaelis 《The Annals of thoracic surgery》1981,32(5):506-509
A blood flow calibration apparatus is described for use with electromagnetic flow probes. It is an automatic gravity-flow system, which provides a constant level and therefore constant flow at any preset rate. On several occasions, the use of this device has helped to determine whether flow probes require simple adjustment, factory repair, or replacement. Using this system, a systematic error in the manufacturer's "precalibration" averaging +22% (range, 9 to 50%) has been discovered, and appropriate corrections have been made. The accuracy of these corrections has been confirmed by a rapid, in vivo method of calibration, which also is described and which can be carried out during the conduct of aortocoronary bypass operation. It is recommended that all groups measuring coronary graft flow become familiar with their electromagnetic flowmeter and probes by means such as those described, in the interest of accurate flow measurement after bypass operation. 相似文献
63.
L. Bertin E. Rey G. Pons J. L. Mathiot M. O. Richard P. Chrétien C. Saint-Maurice C. Moran D. Ginisty G. Olive 《European journal of clinical pharmacology》1991,41(3):251-253
Summary. Twelve healthy children in three age groups anaesthetized for minor surgery were given a single oral dose of tiaprofenic acid (3 mg · kg–1) (TA). Seven blood samples and zero to 8 and 8 to 24 h urines were collected. TA concentrations in plasma and urine were measured by HPLC.No significant difference was found between the age groups in the kinetic parameters of TA and no correlation was found between these parameters and age; tmax=2.12h, Cmax=8.78mg · l–1, AUC(08 h) 33.9mg · h · l–1, AUC=39.3 mg · h · l–1, t1/2=2.35 h, Vz=0.319 l · kg–1, CL=0.094 l · h–1 · kg–1. Renal clearance was 14 ml · h–1. kg–1. 33% of the TA dose was recovered in the 24 h urine, 48% of which was conjugated, whereas in adults, TA is only found in urine as conjugates.The apparent plasma clearance was significantly higher (56%) than in 12 healthy adults given 1.5 mg · kg–1 TA. Volume of distribution and t1/2 did not significantly differ between children and adults. Since no relationship has been established between plasma TA and either efficacy or toxicity, a different dose regimen cannot be recommended in 3–11 year-old children from that in adults. 相似文献
64.
Malignant transformation of a Hürthle cell tumor: case report and survey of the literature 总被引:1,自引:0,他引:1
R J McDonald S Y Wu J L Jensen L N Parker K P Lyons E M Moran W H Blahd 《Journal of nuclear medicine》1991,32(6):1266-1269
Hürthle cell carcinoma is a relatively uncommon type of well-differentiated thyroid carcinoma. Its diagnosis has been controversial due to the difficulty in separating Hürthle cell adenoma from Hürthle cell carcinoma, thus the term Hürthle cell tumor is often used to describe both lesions. The present case of anaplastic giant-cell carcinoma in an 81-yr-old woman arose in a Hürthle cell tumor. This case illustrates the propensity of Hürthle cell tumor to undergo "malignant transformation" and argues for a more aggressive approach to such tumors. 相似文献
65.
This study determines the relative ocular lens irritancy of 16 common partially transparent or non-transparent consumer hygiene products. The irritancy was found by measuring the changes in the sharpness of focus [referred to as the back vertex distance (BVD) variability] of the cultured bovine lens using a scanning laser In Vitro Assay System. This method consists of a laser beam that scans across the lens, and a computer, which then analyses the average focal length (mm), the BVD variability (mm), and the intensity of the beam transmitted. Lenses were exposed to the 16 hygiene products and the lens’ focusing ability was monitored over 192 h. The products are semi-solids or solids (e.g. gels, lotions, shampoos). They are categorized into six groups: shampoos, body washes, lotions, toothpastes, deodorant, and anti-perspirant. Damage (measured by > 1 mm BVD variability) occurred slower for the shampoos, especially in the case of baby shampoo. The results indicate that shampoos exhibit the lowest level of ocular lens toxicity (irritability) while the deodorant is the most damaging. 相似文献
66.
Talan DA Stamm WE Hooton TM Moran GJ Burke T Iravani A Reuning-Scherer J Church DA 《JAMA》2000,283(12):1583-1590
Context The optimal antimicrobial regimen and treatment duration for acute uncomplicated pyelonephritis are unknown. Objective To compare the efficacy and safety of a 7-day ciprofloxacin regimen and a 14-day trimethoprim-sulfamethoxazole regimen for the treatment of acute pyelonephritis in women. Design Randomized, double-blind comparative trial conducted from October 1994 through January 1997. Setting Twenty-five outpatient centers in the United States. Patients Of 378 enrolled premenopausal women aged at least 18 years with clinical diagnosis of acute uncomplicated pyelonephritis, 255 were included in the analysis. Other individuals were excluded for no baseline causative organism, inadequate receipt of study drug, loss to follow-up, no appropriate cultures, and other reasons. Interventions Patients were randomized to oral ciprofloxacin, 500 mg twice per day for 7 days (with or without an initial 400-mg intravenous dose) followed by placebo for 7 days (n = 128 included in analysis) vs trimethoprim-sulfamethoxazole, 160/800 mg twice per day for 14 days (with or without intravenous ceftriaxone, 1 g) (n = 127 included in the analysis). Main Outcome Measure Continued bacteriologic and clinical cure, such that alternative antimicrobial drugs were not required, among evaluable patients through the 4- to 11-day posttherapy visit, compared by treatment group. Results At 4 to 11 days posttherapy, bacteriologic cure rates were 99% (112 of 113) for the ciprofloxacin regimen and 89% (90 of 101) for the trimethoprim-sulfamethoxazole regimen (95% confidence interval [CI] for difference, 0.04-0.16; P = .004). Clinical cure rates were 96% (109 of 113) for the ciprofloxacin regimen and 83% (92 of 111) for the trimethoprim-sulfamethoxazole regimen (95% CI, 0.06-0.22; P = .002). Escherichia coli, which caused more than 90% of infections, was more frequently resistant to trimethoprim-sulfamethoxazole (18%) than to ciprofloxacin (0%; P<.001). Among trimethoprim-sulfamethoxazoletreated patients, drug resistance was associated with greater bacteriologic and clinical failure rates (P<.001 for both). Drug-related adverse events occurred in 24% of 191 ciprofloxacin-treated patients and in 33% of 187 trimethoprim-sulfamethoxazoletreated patients, respectively (95% CI, -0.001 to 0.2). Conclusions In our study of outpatient treatment of acute uncomplicated pyelonephritis in women, a 7-day ciprofloxacin regimen was associated with greater bacteriologic and clinical cure rates than a 14-day trimethoprim-sulfamethoxazole regimen, especially in patients infected with trimethoprim-sulfamethoxazoleresistant strains. 相似文献
67.
BACKGROUND: There is evidence that the stage of illness at which antipsychotic treatment is initiated in schizophrenia may have consequences for its subsequent course. How this might relate to impaired adaptive life functioning in the long-term is poorly understood. METHODS: Thirty-eight inpatients, many of whom had been admitted in the preneuroleptic era, were assessed using the Social-Adaptive Functioning Evaluation (SAFE); constituent clinical and medication phases of the lifetime trajectory of their illnesses were then analyzed to identify predictors of SAFE score using multiple regression modeling. RESULTS: The primary, independent predictor of SAFE score was duration of initially unmedicated psychosis, which accounted for 22% of variance (p<.001) therein. Conversely, duration of subsequently treated illness, although decades longer, failed to predict SAFE score. CONCLUSIONS: These findings are consistent with some form of "progressive" process, particularly over the first several years following the emergence of psychosis, which is associated with accrual of deficits in adaptive life functioning. 相似文献
68.
John L. Moran MBBS FRACP Patricia J. Solomon PhD David E. Warn PhD 《Health services & outcomes research methodology》2004,5(3-4):207-226
Methodological aspects of meta-analytic practice, heterogeneity, publication bias, metaregression and effect metric, were investigated in 14 meta-analyses reflecting major therapeutic concern in Critical Care practice. Compared with the standard Q test, the exact Zelen test was more sensitive in identifying heterogeneity. Assessment of heterogeneity impact by the I 2 statistic was consistent with inferences afforded by both the Q and Zelen test. Publication bias was subject to test and metric determination: funnel plots exhibited variable asymmetry across studies and between metrics; the regression asymmetry test appeared more sensitive than the rank correlation test; the “trim and fill” method was the most sensitive, but suggested, on the basis of quantification of the effects of potentially missing studies, that meta-analyses may be resistant to such missingness. Metaregression of treatment effect against control risk using Bayesian hierarchical regression in all metrics (log odds ratio, log risk ratio and RD) suggested that naïve linear regression approaches over-diagnosed significant relationships and exhibited regression dilution. Heterogeneity, publication bias and risk related treatment effects all demonstrate estimator and metric dependence; the RD metric would appear the most capricious in this regard. 相似文献
69.
Stamm C Friehs I Moran AM Zurakowski D Bacha E Mayer JE Jonas RA Del Nido PJ 《The Journal of thoracic and cardiovascular surgery》2000,120(4):755-763
OBJECTIVE: A number of patients with Williams syndrome or other forms of elastin arteriopathy have stenoses of pulmonary arteries in addition to supravalvular aortic stenosis. We sought to investigate the effect of the degree of pulmonary arterial stenosis on the prognosis after an operation for supravalvular aortic stenosis to help define the optimal treatment strategy for patients with severe forms of elastin arteriopathy. METHODS: Between 1960 and 1999, 33 patients underwent operations for supravalvular aortic stenosis while having significant stenoses of the pulmonary arteries. We retrospectively reviewed patient charts, obtained current follow-up information, and determined risk factors for survival and reoperation. RESULTS: Fifteen patients with moderate right-sided obstructions (confirmed by pulmonary artery Z-scores and right ventricular/descending aortic pressure ratio) underwent operations for supravalvular aortic stenosis only. Eighteen patients had more severe right-sided obstructions and underwent surgical relief of pulmonary arterial stenoses or right ventricular outflow tract obstruction in addition to operations for supravalvular aortic stenosis. Eight patients had undergone preoperative balloon dilations of stenotic pulmonary arteries. There were 6 early deaths and 1 late death in our series. Survival at 10 and 20 years was 76% (70% confidence interval, 68%-84%) and freedom from reintervention was 59% (70% confidence interval, 46%-71%) at 10 years and 49% (70% confidence interval, 35%-62%) at 20 years. Multivariate analysis revealed that patients with a right ventricular/descending aortic pressure ratio of 1.0 or more were at higher risk for reintervention but not for death. CONCLUSIONS: Surgical treatment of pulmonary artery obstructions in elastin arteriopathy is palliative but, in conjunction with balloon dilation of peripheral pulmonary arteries, offers good long-term survival to patients with the severest form of elastin arteriopathy. 相似文献
70.