全文获取类型
收费全文 | 3379篇 |
免费 | 191篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 28篇 |
儿科学 | 69篇 |
妇产科学 | 75篇 |
基础医学 | 373篇 |
口腔科学 | 121篇 |
临床医学 | 231篇 |
内科学 | 678篇 |
皮肤病学 | 115篇 |
神经病学 | 89篇 |
特种医学 | 171篇 |
外国民族医学 | 4篇 |
外科学 | 701篇 |
综合类 | 88篇 |
一般理论 | 2篇 |
预防医学 | 272篇 |
眼科学 | 77篇 |
药学 | 285篇 |
中国医学 | 14篇 |
肿瘤学 | 197篇 |
出版年
2024年 | 2篇 |
2023年 | 32篇 |
2022年 | 110篇 |
2021年 | 206篇 |
2020年 | 102篇 |
2019年 | 131篇 |
2018年 | 144篇 |
2017年 | 90篇 |
2016年 | 111篇 |
2015年 | 131篇 |
2014年 | 169篇 |
2013年 | 195篇 |
2012年 | 255篇 |
2011年 | 311篇 |
2010年 | 187篇 |
2009年 | 154篇 |
2008年 | 209篇 |
2007年 | 210篇 |
2006年 | 181篇 |
2005年 | 144篇 |
2004年 | 121篇 |
2003年 | 137篇 |
2002年 | 102篇 |
2001年 | 21篇 |
2000年 | 23篇 |
1999年 | 21篇 |
1998年 | 9篇 |
1997年 | 5篇 |
1996年 | 12篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1984年 | 4篇 |
1976年 | 7篇 |
1974年 | 1篇 |
1973年 | 3篇 |
1972年 | 3篇 |
1969年 | 3篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1924年 | 1篇 |
1923年 | 1篇 |
1921年 | 1篇 |
排序方式: 共有3590条查询结果,搜索用时 46 毫秒
91.
92.
Curcumin, the yellow spice derived from the roots (rhizomes) of the plant Curcuma longa, has been reported to have a chemoprotective effect against several neoplasms. The protective effect of curcumin during N-nitrosodiethylamine- and carbon tetrachloride-induced hepatocarcinogenesis in Sprague–Dawley rats and its effect on the expression of IkappaB-alpha mRNA were evaluated. Sixty male rats were randomly assigned into four experimental groups. Group A animals received a single i.p. injection of N-nitrosodiethylamine (200 mg/kg b.w.). After 1 week, the animals received weekly s.c. injections of carbon tetrachloride (3 ml/kg b.w./week) for 6 weeks. Group B was given diet containing 0.2 % curcumin 2 weeks before the injection of N-nitrosodiethylamine and continued throughout the experimental period (20 weeks). Group C was given only a diet containing 0.2 % curcumin for the whole period of the experiment. Group D animals served as control. The level of IkappaB-alpha (IкB-α) mRNA was determined by semiquantitative PCR. Administration of diet containing 0.2 % curcumin, 2 weeks before the injection of N-nitrosodiethylamine and throughout the period of experiment, decreased percentage of preneoplastic foci in hepatic parenchyma and inhibited the development of hepatocellular carcinoma, cholangiofibrosis, and cystic cholangioma in rat liver. Moreover, curcumin administration decreased the number and size of the preneoplastic foci induced by N-nitrosodiethylamine and carbon tetrachloride in the liver. The densitometric analysis of the IкB-α mRNA bands revealed that curcumin administration blocked the decrease of IкB-α mRNA induced by N-nitrosodiethylamine and carbon tetrachloride. These results concluded that curcumin inhibited hepatocarcinogenesis induced by N-nitrosodiethylamine and carbon tetrachloride through blocking IкB-α degradation. 相似文献
93.
Walid A. Abdullah Khaled Al-Mutairi Yasser Al-Ali Abdullah Al-Soghier Abdullah Al-Shnwani 《Saudi Dental Journal》2013,25(1):33-38
ObjectiveThe aim of the present study was to study the etiologies and patterns of maxillofacial fractures in patients treated in Riyadh City, Saudi Arabia, between 2007 and 2011.Patients and methodsData were obtained through a retrospective review of 237 patients admitted to the King Saud Medical City Dental Department with a diagnosis of maxillofacial trauma. After excluding patient files with incomplete or unclear records, and cases in which computed tomography showed no evidence of fracture, the files of 200 patients with a diagnosis of maxillofacial fracture were included in the study. For each case, patient’s sex and age, pattern of facial fractures, and cause of injury were recorded on a data sheet. The data were transferred to an SPSS (ver. 16.0; SPSS Inc., Chicago, IL, USA) spreadsheet for statistical analysis. The chi-square test was used to test the association between two categorical variables or factors (age group, cause) with p value set at p<0.05, and t-test value at <0.05 and independent.ResultsMotor vehicle accidents were the most common cause of maxillofacial fractures in most age groups, especially in males. Within the study sample, mandibular fractures were significantly more common than middle-third facial fractures (56.4% vs. 43.6%; p=0.006). Among mandibular fractures, parasymphyseal fractures were most common (47%), followed by condylar fractures (35.3%). Most (77.2%) middle-third facial fractures involved the zygomatic complex, and the incidence of such fractures differed significantly between male and female patients. p=0.72, not significant.ConclusionMales were more prone to maxillofacial fractures, perhaps as a result of the conservative nature of Saudi society, as the rules of Saudi Arabia do not allow the females to drive. Motor vehicle accidents were the most common cause of maxillofacial fractures in patients aged 10–29 years, indicating the high demand for the application of stricter traffic rules to reduce the rate of such accidents. 相似文献
94.
Background
Hip fractures are common injuries in the elderly, with significant associated morbidity and mortality rates. The National Hip Fracture Database (NHFD) was implemented to audit care according to national standards thus improving its clinical and cost-effectiveness.Patients and methods
We retrospectively examined the care pathway for all hip fractures after its introduction at our centre over 1 year, with an audit of care according to the BOA-BGS ‘Blue Book’ guidelines. Data between the first (period 1: initial audit) and second (period 2: re-audit) six months of the study period were compared.Results
There were 372 patients (28% male, 72% female) in total with 190 in period 1 and 182 in period 2. For all patients, the median age was 85 years (range 33–101) and the median time to surgery was 24.5 h (1–519.3), with 251 (67.5%) within 36 h. Surgical delay was mainly due to lack of theatre space (37.6%) and medical reasons (54.7%). The median length of stay was 11 days (2–92) and the inpatient mortality rate was 6.2% (23). When comparing the two study periods, there were significantly more patients undergoing falls (p < 0.01) and bone protection (p < 0.01) assessments in period 2. Lack of theatre space was a significantly less common (p < 0.01), with a significantly shorter median time to surgery (p = 0.01) and length of stay (p < 0.01) in period 2. More patients were discharged to rehabilitation units and the mortality rate was non-significantly lower in period 2 (7.4% vs. 5%). The best practice tariff was met in 45.3% and 70.3% (p < 0.001) of patients in periods 1 and 2 respectively providing a total income of £95230.00 (GBP).Conclusions
Implementing the NHFD has led to an improvement the quality of hip fracture care according to national guidelines. More patients were assessed by an orthogeriatrician, with a shorter time to surgery and length of stay following re-audit. There is potential for an improvement in mortality rates as well as significant financial income for hospitals. 相似文献95.
96.
Lotta LA Mancini I Tuana G Musallam KM Peyvandi F 《Journal of thrombosis and thrombolysis》2012,34(3):416-418
Thienopyridines are commonly used anti-platelet drugs that may be associated with the development of secondary, drug-induced thrombotic thrombocytopenic purpura (TTP), a rare but potentially life threatening condition. We report the case of a 70?year-old man with a history of recurrent idiopathic TTP episodes who was treated with clopidogrel and then ticlopidine for thromboprophylaxis after percutaneous coronary intervention. Treatment was successful with no signs of TTP recurrence. Platelet counts and ADAMTS13 activity levels remained normal for months after the initiation of anti-platelet therapy, with no reappearance of anti-ADAMTS13 autoantibodies. This report demonstrates that thienopyridines do not necessarily induce TTP in patients with a history of TTP who are in disease remission. 相似文献
97.
Laurent Roten Nicolas Derval Patrizio Pascale Daniel Scherr Yuki Komatsu Ashok Shah Khaled Ramoul Arnaud Denis Frédéric Sacher Mélèze Hocini Michel Ha?ssaguerre Pierre Ja?s 《Current Cardiology Reviews》2012,8(4):327-346
Atrial fibrillation (AF) ablation has evolved to the treatment of choice for patients with drug-resistant and symptomatic AF. Pulmonary vein isolation at the ostial or antral level usually is sufficient for treatment of true paroxysmal AF. For persistent AF ablation, drivers and perpetuators outside of the pulmonary veins are responsible for AF maintenance and have to be targeted to achieve satisfying arrhythmia-free success rate. Both complex fractionated atrial electrogram (CFAE) ablation and linear ablation are added to pulmonary vein isolation for persistent AF ablation. Nevertheless, ablation failure and necessity of repeat ablations are still frequent, especially after persistent AF ablation. Pulmonary vein reconduction is the main reason for arrhythmia recurrence after paroxysmal and to a lesser extent after persistent AF ablation. Failure of persistent AF ablation mostly is a consequence of inadequate trigger ablation, substrate modification or incompletely ablated or reconducting linear lesions. In this review we will discuss these points responsible for AF recurrence after ablation and review current possibilities on how to overcome these limitations. 相似文献
98.
P. Abdul Rasheed Ravi P. Pandey Tricia Gomez Michael Naguib Khaled A. Mahmoud 《RSC advances》2020,10(41):24697
A Nb4C3Tx (MXene)-modified glassy carbon electrode was used for the electrochemical detection of Pb2+ ions in aqueous media. The sensing platform was evaluated by anodic stripping analysis after optimizing the influencing factors such as pH, deposition potential, and time. The large interlayer spacing, high c lattice parameter and higher conductivity of Nb4C3Tx compared to other MXenes enhance the electrochemical detection of Pb2+. The developed sensor can reach a detection limit of 12 nM at a potential ∼−0.6 V. Additionally, the developed sensor showed promising selectivity in the presence of Cu2+ and Cd2+, and stability for at least 5 cycles of continuous measurements with good repeatability. This work demonstrates the potential applications of Nb4C3Tx towards the development of effective electrochemical sensors.Large interlayer spacing Nb4C3Tx (MXene) promotes the ultrasensitive electrochemical detection of Pb2+ on glassy carbon electrodes 相似文献
99.
100.
Jörg A. K. Ohnsorge Khaled H. Salem Andreas Ladenburger Uwe M. Maus Markus Weißkopf 《European spine journal》2013,22(3):642-647