全文获取类型
收费全文 | 3030篇 |
免费 | 126篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 55篇 |
儿科学 | 54篇 |
妇产科学 | 170篇 |
基础医学 | 414篇 |
口腔科学 | 58篇 |
临床医学 | 191篇 |
内科学 | 817篇 |
皮肤病学 | 80篇 |
神经病学 | 262篇 |
特种医学 | 54篇 |
外科学 | 406篇 |
综合类 | 16篇 |
预防医学 | 165篇 |
眼科学 | 37篇 |
药学 | 263篇 |
中国医学 | 7篇 |
肿瘤学 | 118篇 |
出版年
2023年 | 25篇 |
2022年 | 23篇 |
2021年 | 54篇 |
2020年 | 42篇 |
2019年 | 67篇 |
2018年 | 115篇 |
2017年 | 97篇 |
2016年 | 81篇 |
2015年 | 102篇 |
2014年 | 116篇 |
2013年 | 154篇 |
2012年 | 247篇 |
2011年 | 302篇 |
2010年 | 130篇 |
2009年 | 91篇 |
2008年 | 175篇 |
2007年 | 199篇 |
2006年 | 210篇 |
2005年 | 203篇 |
2004年 | 162篇 |
2003年 | 166篇 |
2002年 | 139篇 |
2001年 | 21篇 |
2000年 | 35篇 |
1999年 | 17篇 |
1998年 | 14篇 |
1997年 | 7篇 |
1996年 | 8篇 |
1995年 | 5篇 |
1993年 | 4篇 |
1992年 | 7篇 |
1990年 | 12篇 |
1989年 | 8篇 |
1988年 | 10篇 |
1987年 | 7篇 |
1986年 | 11篇 |
1985年 | 14篇 |
1984年 | 7篇 |
1983年 | 8篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 5篇 |
1975年 | 4篇 |
1974年 | 5篇 |
1971年 | 4篇 |
1970年 | 3篇 |
1969年 | 6篇 |
1968年 | 5篇 |
1933年 | 6篇 |
排序方式: 共有3167条查询结果,搜索用时 20 毫秒
81.
82.
Z?bczyk M Butenas S Plicner D Fijorek K Sadowski J Undas A 《Blood coagulation & fibrinolysis》2012,23(3):189-194
Circulating active tissue factor (TF) and activated factor XI (FXIa) have been detected in subgroups of acute coronary syndromes (ACSs) and stable angina patients. We sought to evaluate the determinants of active TF and FXIa in stable angina patients. We studied 124 consecutive stable angina patients. Recent ACS, atrial fibrillation, and anticoagulant therapy were the exclusion criteria. Plasma active TF and FXIa were determined by measuring the response to inhibitory antibodies. T helper 1 lymphocyte (Th1) and Th2 responses were assessed in plasma by interleukin (IL)-4, IL-6, IL-8, IL-10, IL-18, interferon-γ, and tumor necrosis factor-α, oxidative stress by 8-isoprostaglandin F(2α) (8-iso-PGF(2α)), and coagulation by prothrombin fragments F1+2 (F1+2) and free TF pathway inhibitor (f-TFPI). TF and FXIa activity were detected in 25 (20.2%) and 49 (39.5%) stable angina patients, respectively. Both factors were found in 23 (18.5%) patients. Patients with detectable TF or FXIa had higher F1+2, 8-iso-PGF(2α), IL-6, but not other cytokines, and lower f-TFPI (all P < 0.001) compared with the remainder. There were no intergroup differences with regard to cardiovascular risk factors or medication. Multivariate analysis showed that F1+2 and f-TFPI were the only independent predictors of the TF presence, whereas 8-iso-PGF(2α) and F1+2 predicted the presence of FXIa in stable angina patients. In stable angina patients, circulating active TF and FXIa are associated with enhanced thrombin formation, with a minor effect of inflammatory mediators. Moreover, FXIa is also related to oxidative stress, indicating additional links between coagulation and free radical generation in stable angina. 相似文献
83.
Bembenek JP Karlinski M Kobayashi A Czlonkowska A 《Clinical and applied thrombosis/hemostasis》2012,18(3):258-264
Deep venous thrombosis (DVT) is a complication of stroke. Our aim was to determine the frequency of DVT in patients with acute stroke, risk factors for its development, and its influence on the 3-month outcome. A total of 323 consecutive patients with acute stroke were enrolled. We performed ultrasound imaging within 7 days after stroke. Deep venous thrombosis was found in 8.7% of patients, only in those with ischemic stroke. Patients with DVT were more frequently female (71.4% vs 49.5%), had prestroke Modified Rankin scale (mRS) 3 to 5 (42.9% vs 15.3%), elevated C-reactive protein (CRP) serum level (65.4% vs 32.5%), and a trend toward elevated serum fibrinogen level (85.7% vs 70.1%; P = .08). In a multivariate analysis, elevated CRP (odds ratio [OR] 3.15) and prestroke disability (OR 2.89) were independent risk factors for DVT. Deep venous thrombosis occurs in <10% of patients with acute stroke and does not significantly affect the 3-month outcome. Prestroke dependency and elevated CRP level at baseline are independent risk factors for DVT. 相似文献
84.
Helene Wagner Håkan Melhus Nancy L. Pedersen Karl Michaëlsson 《Journal of bone and mineral metabolism》2013,31(6):681-689
Bone mineral density (BMD), bone size and bone turnover are independent determinants of fractures in elderly. Earlier twin studies of these phenotypes have revealed high heritability for BMD and bone area, and more moderate heritability for bone turnover markers. No previous Scandinavian study has evaluated the genetic and environmental contribution to the variance of these phenotypes, despite the fact that Scandinavian countries have the highest incidence of osteoporotic fractures worldwide. Participants were selected from the Swedish Twin Registry. All intact like-sexed twin pairs born in 1965 or earlier and living in the county of Uppsala were invited to participate. A total of 102 twin pairs (45 monozygotic and 57 dizygotic) accepted the invitation to participate. All twins underwent measurement of BMD and bone area using dual-energy X-ray absorptiometry. Hip geometry was also calculated. Markers for bone formation (osteocalcin) and bone resorption (CrossLaps) were measured in serum. We observed a substantial heritability for BMD at the lumbar spine (0.85; 95 % CI 0.54–0.90), the femoral neck (0.75; 95 % CI 0.62–0.83), and the proximal femur (0.84; 95 % CI 0.74–0.90). The values for bone area were approximately similar to those for BMD. Bone turnover markers had a slightly lower genetic influence with a value of 0.69 (0.53–0.80) for osteocalcin and 0.58 (95 % CI 0.33–0.75) for CrossLaps. As a comparison, the heritabilities of body height and weight were 0.95 and 0.82, respectively. The high heritability on bone phenotypes among Swedish middle-aged and older men and women should encourage further work on the identification of specific genetic pathways. Continuing research in this area could reveal the mechanisms behind the strong genetic susceptibility of bone-related phenotypes. 相似文献
85.
Jan Gunst Ilse Vanhorebeek Micha?l P. Casaer Greet Hermans Pieter J. Wouters Jasperina Dubois Kathleen Claes Miet Schetz Greet Van den Berghe 《Journal of the American Society of Nephrology : JASN》2013,24(6):995-1005
A poor nutritional state and a caloric deficit associate with increased morbidity and mortality, but a recent multicenter, randomized controlled trial found that early parenteral nutrition to supplement insufficient enteral nutrition increases morbidity in the intensive care unit, including prolonging the duration of renal replacement therapy, compared with withholding parenteral nutrition for 1 week. Whether early versus late parenteral nutrition impacts the incidence and recovery of AKI is unknown. Here, we report a prespecified analysis from this trial, the Early Parenteral Nutrition Completing Enteral Nutrition in Adult Critically Ill Patients (EPaNIC) study. The timing of parenteral nutrition did not affect the incidence of AKI, but early initiation seemed to slow renal recovery in patients with stage 2 AKI. Early parenteral nutrition did not affect the time course of creatinine and creatinine clearance but did increase plasma urea, urea/creatinine ratio, and nitrogen excretion beginning on the first day of amino acid infusion. In the group that received late parenteral nutrition, infusing amino acids after the first week also increased ureagenesis. During the first 2 weeks, ureagenesis resulted in net waste of 63% of the extra nitrogen intake from early parenteral nutrition. In conclusion, early parenteral nutrition does not seem to impact AKI incidence, although it may delay recovery in patients with stage 2 AKI. Substantial catabolism of the extra amino acids, which leads to higher levels of plasma urea, might explain the prolonged duration of renal replacement therapy observed with early parenteral nutrition.The development of AKI is a frequent and devastating condition in patients admitted to the intensive care unit (ICU). Short-term mortality is high and increases with worsening AKI stages.1 In AKI survivors, renal recovery is often incomplete, progression to ESRD may be accelerated, and longer-term mortality rates are increased compared with non-AKI patients.2,3 Patient management consists of maximal prevention of additional renal damage by hemodynamic stabilization and prevention of (iatrogenic) nephrotoxicity. A curative strategy for established AKI is currently unavailable.4Observational studies, finding associations between a poor nutritional state and increased morbidity and mortality of AKI patients5 and between accumulation of a caloric deficit and poor renal and survival outcome of ICU patients,6,7 have led to the hypothesis that feeding could ameliorate kidney injury and improve survival of ICU patients. However, nutrition, especially parenteral nutrition (PN), also has potential complications.8–11 Because of the lack of adequately designed studies, nutritional guidelines are largely based on expert opinion.12–14 These opinions invariably recommend the early initiation of enteral feeding but substantially differ in their recommendation on when to start supplemental PN.The Early Parenteral Nutrition Completing Enteral Nutrition in Adult Critically Ill Patients (EPaNIC) study was the first large, multicenter, randomized controlled trial (RCT) addressing this important question. The study showed that early initiation of PN increased dependency on intensive care compared with withholding supplemental PN for 1 week (hereafter labeled early PN and late PN, respectively).15 Indeed, early PN prolonged the ICU and hospital length of stay (LOS), increased the incidence of new infections, and prolonged the need for mechanical ventilation. Renal harm was suggested by a clear prolongation of the duration of renal replacement therapy (RRT) in ICU and a trend for more AKI (defined as a doubling or more of ICU admission plasma creatinine). However, the number of patients requiring RRT was unaltered, and recovery to premorbid kidney function was not investigated.It was preplanned to study the detailed impact of early versus late PN on the incidence and recovery of AKI and the time course of blood/urine markers of renal function during ICU stay.16
A priori, we hypothesized that early PN would attenuate kidney injury. However, the original study findings suggested that AKI incidence and renal recovery could be aggravated by increased macronutrient provision in the acute phase of critical illness. 相似文献
86.
Michaël Papaloïzos 《Journal of plastic surgery and hand surgery》2013,47(5):310-313
Phylogenetically the accessory extensor pollicis longus in man seems to find its origin in the deep extensor layer, and this has largely been described in primates. I describe a case and present a comprehensive review of other publications on the subject. 相似文献
87.
Piotr Ładziński Mariusz Maliszewski Wojciech Kaspera Krzysztof Majchrzak Michał Tymowski Bartłomiej Błaszczyk 《Neurologia i neurochirurgia polska》2013,47(4):375-386
The aim of the study was to present consecutive stages of the posterior petrosal approach (PPA).Eighteen simulations of PPA were performed on non-fixed human cadavers without any known pathologies in the head and neck. The consecutive stages of the procedure were documented with photographs and schemes.The starting point for PPA is a temporal craniotomy, suboccipital craniectomy and mastoidectomy with keeping the bony labyrinth intact. Approach to the middle part of the clivus is achieved by raise of the temporal lobe and section of the superior petrosal sinus and tentorium and by mobilization the sigmoid sinus.Posterior petrosal approach is a reproducible technique, which provides surgical penetration of the middle clivus and related regions. It reduces the operating distance and allows to limit the cerebellum and temporal lobe traction and to preserve the anatomic integrity of the brain stem and cranial nerves of the cerebellopontine angle. 相似文献
88.
89.
90.
Liisa Byberg Andrea Bellavia Susanna C Larsson Nicola Orsini Alicja Wolk Karl Michaëlsson 《Journal of bone and mineral research》2016,31(12):2098-2105
A Mediterranean diet, known to have beneficial effects on cardiovascular health, may also influence the risk of hip fracture although previous studies present discrepant results. We therefore aimed to determine whether the rate of hip fracture was associated with degree of adherence to a Mediterranean diet. We combined two Swedish cohort studies consisting of 37,903 men and 33,403 women (total n = 71,333, mean age 60 years) free of previous cardiovascular disease and cancer who answered a medical and a food‐frequency questionnaire in 1997. A modified Mediterranean diet score (mMED; range, 0 to 8 points) was created based on high consumption of fruits and vegetables, legumes and nuts, whole grains, fermented dairy products, fish, and olive/rapeseed oil, moderate intake of alcohol, and low intake of red and processed meat. Incident hip fractures between January 1, 1998, and December 31, 2012, were retrieved from the National Patient Register. Hazard ratios (HRs) and 95% confidence intervals (CIs) adjusted for potential confounders were calculated using Cox proportional hazards regression. Differences in age at hip fracture were calculated using multivariable Laplace regression. During follow‐up, 3175 hip fractures occurred at a median age of 73.3 years. One unit increase in the mMED was associated with 6% lower hip fracture rate (adjusted HR = 0.94; 95% CI, 0.92 to 0.96) and with a 3‐month higher median age at hip fracture (50th percentile difference = 2.8 months; 95% CI, 1.4 to 4.2). Comparing the highest quintile of adherence to the mMED (6 to 8 points) with the lowest (0 to 2 points) conferred an adjusted HR of hip fracture of 0.78 (95% CI, 0.69 to 0.89) and a 12‐month higher median age of hip fracture (50th percentile difference = 11.6 months; 95% CI, 4.2 to 19.0). Results were similar in men and women. We conclude that higher adherence to a Mediterranean‐like diet is associated with lower risk of future hip fracture. © 2016 American Society for Bone and Mineral Research. 相似文献