全文获取类型
收费全文 | 1661篇 |
免费 | 127篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 73篇 |
妇产科学 | 19篇 |
基础医学 | 201篇 |
口腔科学 | 115篇 |
临床医学 | 127篇 |
内科学 | 218篇 |
皮肤病学 | 36篇 |
神经病学 | 435篇 |
特种医学 | 39篇 |
外科学 | 194篇 |
综合类 | 72篇 |
一般理论 | 26篇 |
预防医学 | 118篇 |
眼科学 | 19篇 |
药学 | 73篇 |
中国医学 | 1篇 |
肿瘤学 | 33篇 |
出版年
2021年 | 13篇 |
2020年 | 11篇 |
2019年 | 22篇 |
2018年 | 23篇 |
2017年 | 18篇 |
2016年 | 30篇 |
2015年 | 19篇 |
2014年 | 37篇 |
2013年 | 59篇 |
2012年 | 59篇 |
2011年 | 73篇 |
2010年 | 38篇 |
2009年 | 38篇 |
2008年 | 68篇 |
2007年 | 83篇 |
2006年 | 66篇 |
2005年 | 71篇 |
2004年 | 79篇 |
2003年 | 55篇 |
2002年 | 57篇 |
2001年 | 42篇 |
2000年 | 58篇 |
1999年 | 74篇 |
1998年 | 29篇 |
1997年 | 12篇 |
1996年 | 12篇 |
1995年 | 12篇 |
1994年 | 14篇 |
1993年 | 17篇 |
1992年 | 50篇 |
1991年 | 52篇 |
1990年 | 53篇 |
1989年 | 47篇 |
1988年 | 45篇 |
1987年 | 32篇 |
1986年 | 37篇 |
1985年 | 35篇 |
1984年 | 17篇 |
1983年 | 28篇 |
1982年 | 13篇 |
1981年 | 10篇 |
1980年 | 14篇 |
1979年 | 18篇 |
1978年 | 27篇 |
1977年 | 10篇 |
1976年 | 11篇 |
1975年 | 11篇 |
1973年 | 10篇 |
1967年 | 11篇 |
1966年 | 15篇 |
排序方式: 共有1803条查询结果,搜索用时 15 毫秒
41.
Nils Henninger Diogo C. Haussen Nikolaos Kakouros Magdy Selim D. Eric Searls Sandeep Kumar Gottfried Schlaug Louis R. Caplan 《Neurocritical care》2013,19(2):167-175
Background and Purpose
To evaluate the relationship between infarct location and QTc-prolongation in patients with posterior circulation strokes.Methods
Admission electrocardiograms (ECG) of 131 patients among a prospective sample of 407 consecutive adult patients in the New England Medical Center Posterior Circulation Registry were retrospectively analyzed. The QT interval (ms) was measured and corrected using Bazett’s formula (QTcBazett) as well as linear regression functions (QTcLinear). QTcBazett > 440 ms and QTcLinear ≥ 450 ms for men (≥460 ms for women) were considered prolonged. Multivariable linear and logistic regression analyses were used to identify independent predictors of the QTc.Results
Overall, 34 % of patients had a prolonged QTcBazett and 7 % had a prolonged QTcLinear noted on the admission ECG. There was a significant association between temporal lobe infarction and QTcBazett and QTcLinear (p < 0.001 for both) in multivariable linear regression analyses adjusting for demographics, ECG parameters, and preadmission medication use. In multivariable logistic regression analysis, temporal lobe infarction emerged as an independent predictor of prolonged QTcBazett (p = 0.009) and QTcLinear (p = 0.008), respectively. Sensitivity analyses excluding patients with transient ischemic attack yielded similar results. Exploratory analyses indicated that patients with temporal lobe infarction had worse functional 30-day outcomes in multivariable logistic regression (p = 0.022). However, there was no significant association between QTc and 30-day functional outcome.Conclusions
QTc-prolongation is common after posterior circulation stroke and associated with temporal lobe infarction. Prospective studies are needed to confirm these preliminary findings and to examine potential long-term consequences. 相似文献42.
43.
Liu J Johnson TV Lin J Ramirez SH Bronich TK Caplan S Persidsky Y Gendelman HE Kipnis J 《European journal of immunology》2007,37(11):3143-3154
Despite active investigation of copolymer-1 (Cop-1) for nearly 40 years the mechanisms underlying its neuroprotective properties remain contentious. Nonetheless, current dogma for Cop-1 neuroprotective activities in autoimmune and neurodegenerative diseases include bystander suppression of autoimmune T cells and attenuation of microglial responses. In this report, we demonstrate that Cop-1 interacts directly with primary human neurons and decreases neuronal cell death induced by staurosporine or oxidative stress. This neuroprotection is mediated through protein kinase Calpha and brain-derived neurotrophic factor. Dendritic cells (DC) uptake Cop-1, deliver it to the injury site, and release it in an active form. Interactions between Cop-1 and DC enhance DC blood brain barrier migration. In a rat model with optic nerve crush injury, Cop-1-primed DC induce T cell independent neuroprotection. These findings may facilitate the development of neuroprotective approaches using DC-mediated Cop-1 delivery to diseased nervous tissue. 相似文献
44.
45.
Satterfield BC Kulesh DA Norwood DA Wasieloski LP Caplan MR West JA 《Clinical chemistry》2007,53(12):2042-2050
BACKGROUND: False-positive results are a common problem in real-time PCR identification of DNA sequences that differ from near neighbors by a single-nucleotide polymorphism (SNP) or deletion. Because of a lack of sufficient probe specificity, post-PCR analysis, such as a melting curve, is often required for mutation differentiation. METHODS: Tentacle Probes, cooperative reagents with both a capture and a detection probe based on specific cell-targeting principles, were developed as a replacement for 2 chromosomal TaqMan-minor groove binder (MGB) assays previously developed for Yersinia pestis and Bacillus anthracis detection. We compared TaqMan-MGB probes to Tentacle Probes for SNP and deletion detection based on the presence or absence of a growth curve. RESULTS: With the TaqMan-MGB Y. pestis yp48 assays, false-positive results for Yersinia pseudotuberculosis occurred at every concentration tested, and with the TaqMan-MGB B. anthracis gyrA assays, false-positive results occurred in 21 of 29 boil preps of environmental samples of near neighbors. With Tentacle Probes no false-positive results occurred. CONCLUSIONS: The high specificity exhibited by Tentacle Probes may eliminate melting curve analysis for SNP and deletion mutation detection, allowing the diagnostic use of previously difficult targets. 相似文献
46.
SH2D1A regulates T-dependent humoral autoimmunity 总被引:4,自引:0,他引:4
Hron JD Caplan L Gerth AJ Schwartzberg PL Peng SL 《The Journal of experimental medicine》2004,200(2):261-266
The signaling lymphocytic activation molecule (SLAM)/CD150 family includes a family of chromosome 1-encoded cell surface molecules with costimulatory functions mediated in part by the adaptor protein SH2D1A (SLAM-associated protein, SAP). Deficiency in SH2D1A protects mice from an experimental model of lupus, including the development of hypergammaglobulinemia, autoantibodies including anti-double stranded DNA, and renal disease. This protection did not reflect grossly defective T or B cell function per se because SH2D1A-deficient mice were susceptible to experimental autoimmune encephalomyelitis, a T cell-dependent disease, and they were capable of mounting normal T-independent antigen-specific immunoglobulin responses. Instead, T-dependent antibody responses were impaired in SH2D1A-deficient mice, reflecting defective germinal center formation. These findings demonstrate a specific role for the SLAM-SH2D1A system in the regulation of T-dependent humoral immune responses, implicating members of the CD150-SH2D1A family as targets in the pathogenesis and therapy of antibody-mediated autoimmune and allergic diseases. 相似文献
47.
Ian F. Caplan Eric Winter Gregory Glauser Stephen Goodrich Scott D. McClintock Eric L. Hume Neil R. Malhotra 《Journal of orthopaedic research》2020,38(10):2189-2196
The LACE+ (Length of stay, Acuity of admission, Charlson Comorbidity Index score, and Emergency department visits in the past 6 months) risk-prediction tool has never been tested in an orthopedic surgery population. LACE+ may help physicians more effectively identify and support high-risk orthopedics patients after hospital discharge. LACE+ scores were retrospectively calculated for all consecutive orthopedic surgery patients (n = 18 893) at a multi-center health system over 3 years (2016-2018). Coarsened exact matching was employed to create “matched” study groups with different LACE+ score quartiles (Q1, Q2, Q3, Q4). Outcomes were compared between quartiles. In all, 1444 patients were matched between Q1 and Q4 (n = 2888); 2079 patients between Q2 and Q4 (n = 4158); 3032 patients between Q3 and Q4 (n = 6064). Higher LACE+ scores significantly predicted 30D readmission risk for Q4 vs Q1 and Q4 vs Q3 (P < .001). Larger LACE+ scores also significantly predicted 30D risk of ED visits for Q4 vs Q1, Q4 vs Q2, and Q4 vs Q3 (P < .001). Increased LACE+ score also significantly predicted 30D risk of reoperation for Q4 vs Q1 (P = .018), Q4 vs Q2 (P < .001), and Q4 vs Q3 (P < .001). 相似文献
48.
Caplan LR 《Current treatment options in cardiovascular medicine》2003,5(3):251-256
Opinion statement Atherosclerotic lesions are very common at the origin and first few centimeters of the vertebral artery in the neck. These
lesions are often missed when using noninvasive diagnostic strategies. These lesions cause transient hypoperfusion and transient
ischemic attacks, characterized mostly by vestibulocerebellar symptoms. Strokes are caused by embolism from these lesions.
Patients with nonstenosing vertebral artery plaques should be treated with statins and antiplatelet agents. Symptomatic patients
who have had embolism from an occluded vertebral artery should be treated with heparin followed by warfarin for a period of
4 to 12 weeks. Antiplatelet agents can then be given. The optimal treatment of asymptomatic and symptomatic patients with
severe vertebral artery stenosis is unclear. Statins and warfarin are recommended for patients with concurrent stenotic lesions
of the contralateral extracranial vertebral artery, the intracranial vertebral or basilar arteries, or the anterior circulation
arteries. Balloon angioplasty or stenting will likely prove superior to surgery in those patients with severe stenosis who
do not respond to medical treatment. 相似文献
49.
Alex McLaren MD Morgan B. Giers PhD James Fraser MD MPH Luke Hosack MD Michael R. Caplan PhD Ryan McLemore PhD 《Clinical orthopaedics and related research》2014,472(11):3324-3329
Background
Tissue distribution after local delivery has been quantified over a period of 5 hours on 7-T MRI in a rabbit model using gadolinium-labeled diethylenetriamine pentaacetic acid (Gd-DTPA) as an antimicrobial surrogate; however, it is unknown how the Gd-DTPA load in a local depot will affect the duration of high-concentration Gd-DTPA in local tissues after surgical débridement.Questions/purposes
We determined whether the Gd-DTPA load in bone cement affected its local tissue distribution over a period of 1 month after local delivery.Methods
A 1-cm3 soft tissue dead space was created in the quadriceps of seven rabbits and filled with gadolinium-loaded bone cement. At 7, 14, and 33 days, the volume of tissue with a Gd-DTPA concentration of more than 14 μg/mL was calculated from T1-weighted images using 7-T MRI. Differences in volumes of distribution were analyzed with ANOVA.Results
The volume of tissue with more than 14 μg/mL Gd-DTPA was much larger from higher gadolinium loads on Day 7 (p = 0.02) (2121 mm3 for 10 g and 665 mm3 for 1 g) and smaller with time for the 10-g formulation (2121 mm3 on Day 7 and 1241 mm3 on Day 14).Conclusions
Volume of distribution and duration of Gd-DTPA after local delivery increased with increasing load in the cement and decreased with time.Clinical Relevance
For local delivery, high antimicrobial concentrations would be expected in greater volumes of tissue, for longer durations, when higher antimicrobial loads are used. 相似文献50.