首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2687篇
  免费   213篇
  国内免费   7篇
耳鼻咽喉   5篇
儿科学   84篇
妇产科学   41篇
基础医学   472篇
口腔科学   15篇
临床医学   313篇
内科学   536篇
皮肤病学   78篇
神经病学   355篇
特种医学   66篇
外科学   225篇
综合类   5篇
预防医学   221篇
眼科学   31篇
药学   181篇
中国医学   1篇
肿瘤学   278篇
  2024年   2篇
  2023年   25篇
  2022年   57篇
  2021年   100篇
  2020年   66篇
  2019年   85篇
  2018年   104篇
  2017年   74篇
  2016年   68篇
  2015年   97篇
  2014年   113篇
  2013年   128篇
  2012年   247篇
  2011年   264篇
  2010年   128篇
  2009年   132篇
  2008年   198篇
  2007年   196篇
  2006年   162篇
  2005年   162篇
  2004年   141篇
  2003年   133篇
  2002年   103篇
  2001年   17篇
  2000年   11篇
  1999年   15篇
  1998年   19篇
  1997年   9篇
  1996年   10篇
  1995年   4篇
  1994年   5篇
  1993年   5篇
  1992年   4篇
  1991年   1篇
  1990年   2篇
  1989年   3篇
  1988年   1篇
  1986年   3篇
  1985年   2篇
  1984年   2篇
  1983年   1篇
  1980年   1篇
  1979年   3篇
  1977年   1篇
  1975年   1篇
  1973年   2篇
排序方式: 共有2907条查询结果,搜索用时 31 毫秒
41.
The proprotein convertases (PCs) furin and PACE4 process numerous substrates involved in tumor growth, invasion, and metastasis. We have previously shown that PCs increase the susceptibility to chemical skin carcinogenesis. Because of the human relevancy of UV radiation in the etiopathogenesis of human skin cancer, we investigated whether or not transgenic mice overexpressing either furin alone or both furin and PACE4 show increased susceptibility to UV carcinogenesis. After backcrossing our previously described furin and PACE4 transgenic lines, targeted to the epidermis, into a SKH-1 background, we exposed both single and double transgenic mice to UV radiation for 34 weeks. The results showed an increase in squamous cell carcinoma (SCC) multiplicity of approximately 70% in the single furin transgenic mouse line SF47 (P < .002) and a 30% increase in the other single transgenic line SF49 when compared to wild-type (WT) SKH-1 mice. Interestingly, there was also an increase in the percentage of high histologic grade SCCs in the transgenic lines compared to the WT mice, i.e., WT = 9%, SF47 = 15%, and SF49 = 26% (P < .02). Targeting both furin and PACE4 to the epidermis in double transgenic mice did not have an additive effect on tumor incidence/multiplicity but did enhance the tumor histopathologic grade, i.e., a significant increase in higher grade SCCs was seen in the bigenic mouse line SPF47 (P < .02). Thus, we observed an increased susceptibility to UV in single furin transgenic mice that was not substantially enhanced in the double furin/PACE4 transgenic mice.  相似文献   
42.
Although chemoembolization is known to be an effective palliative treatment in hepatocellular carcinoma, it has a limited effect in large tumors. We report the case of a patient with a large hepatocellular carcinoma of the left liver who had a significant and sustained clinical response after six sessions of chemoembolization with a pirarubicin/amiodarone/lipiodol emulsion. Pirarubicin is an anthracycline which penetrates faster than doxorubicin into cancer cells. Amiodarone is a multidrug resistance inhibitor. Polysorbate 80, an excipient of injectable amiodarone stabilizes the anthracycline/lipiodol emulsion. The clinical efficacy of this new formulation could be evaluated in a phase II clinical trial.  相似文献   
43.
Blood fluidity is related to the ability to oxidize lipids at exercise   总被引:5,自引:0,他引:5  
We previously reported in rugbywomen correlations between RBC deformability and the ability to oxidize at exercise more lipids. This surprising finding might of course be spurious, or reflect the importance of the balance of substrates at exercise on baseline parameters that regulate blood rheology. Actually, the capacity of skeletal muscle to utilize either lipid or carbohydrate as fuels strongly influences whole body metabolism both at rest and during exercise. While the healthy skeletal muscle has substantial metabolic flexibility and is able to switch from predominantly lipid o oxidation during fasting or endurance exercise to increased glucose oxidation in conditions of insulin stimulation, obese individuals and those with type 2 diabetes manifest higher lipid oxidation during insulin-stimulated conditions despite lower rates of lipid oxidation during fasting or prolonged exercise. A low ability to oxidize and to periodically deplete triglyceride in muscle is associated with raised blood lipids. In addition, high carbohydrate oxidation rates in the mitochondrion are likely to promote more free radical generation. An increase in either blood lipids or free radicals is likely to induce profound hemorheological effects. We present here hemorheological studies in various populations with the use of exercise calorimetry in order to assess this switch of substrates. These studies further evidence negative correlations between the ability to oxidize lipids at exercise and parameters of blood viscosity. Correlations found between RBC deformability and the ability to oxidize at exercise more lipids may be due to effects of endurance training on lipid oxidation which may in turn modify both lipid metabolism and free radical generation, thus influencing RBC rheology.  相似文献   
44.
Analysis of the spatiotemporal coupling between neuronal activity and cerebral blood flow requires the precise measurement of the dynamics of RBC flow in individual capillaries that irrigate activated neurons. Here, we use two-photon microscopy in vivo to image individual RBCs in glomerular capillaries in the rat dorsal olfactory bulb. We find that odor stimulation evokes capillary vascular responses that are odorant- and glomerulus-specific. These responses consist of increases as well as decreases in RBC flow, both resulting from independent changes in RBC velocity or linear density. Finally, measuring RBC flow with micrometer spatial resolution and millisecond temporal resolution, we demonstrate that, in olfactory bulb superficial layers, capillary vascular responses precisely outline regions of synaptic activation.  相似文献   
45.
Clinical Rheumatology - To examine the mortality rates and causes of death among French decedents with Behçet’s disease (BD). Data collected between 1979 and 2016 by the French...  相似文献   
46.
Journal of Thrombosis and Thrombolysis - Bone marrow biopsies are largely used for the diagnosis and prognostic of various hematological diseases. Complications are rare but can be as serious as...  相似文献   
47.
To encourage the process of harmonization, the biobank community should support and use a common terminology. Relevant terms may be found in general thesauri for medicine, legal instruments or specific glossaries for biobanking. A comparison of the use of these sources has so far not been conducted and would be a useful instrument to further promote harmonization and data sharing. Thus, the purpose of the present study was to investigate the preference of definitions important for sharing biological samples and data. Definitions for 10 terms –[human] biobank, sample/specimen, sample collection, study, aliquot, coded, identifying information, anonymised, personal data and informed consent–were collected from several sources. A web-based questionnaire was sent to 560 European individuals working with biobanks asking to select their preferred definition for the terms. A total of 123 people participated in the survey, giving a response rate of 23%. The result was evaluated from four aspects: scope of definitions, potential regional differences, differences in semantics and definitions in the context of ontologies, guided by comments from responders. Indicative from the survey is the risk of focusing only on the research aspect of biobanking in definitions. Hence, it is recommended that important terms should be formulated in such a way that all areas of biobanking are covered to improve the bridges between research and clinical application. Since several of the terms investigated here within can also be found in a legal context, which may differ between countries, establishing what is a proper definition on how it adheres to law is also crucial.  相似文献   
48.

Background

This paper investigates risk factors for the development of posttraumatic stress symptoms in the different survivor groups involved in a technological disaster in Ghislenghien (Belgium). A gas explosion instantly killed five firefighters, one police officer and 18 other people. Moreover, 132 people were wounded among which many suffered severe burn injuries.

Methods

In the framework of a large health survey of people potentially involved in the disaster, data were collected from 3,448 households, of which 7,148 persons aged 15 years and older, at 5 months (T1) and at 14 months (T2) after the explosion. Hierarchical regression was used to determine the significant predictors and to assess their proportion in variance accounted for.

Results

The degree of exposure to the disaster was a predictor of the severity of posttraumatic stress symptoms. Peritraumatic dissociation appeared to be the most important predictor of the development of posttraumatic stress symptoms at T1. But at T2, posttraumatic stress symptoms at T1 had become the most important predictor. Dissatisfaction with social support was positively linked to development of posttraumatic stress symptoms at T1 and to the maintenance of these symptoms at T2. Survivors who received psychological help reported significant benefits.

Conclusions

In harmony with the findings from studies on technological disasters, at T1 6,0% of the respondents showed sufficient symptoms to meet all criteria for a full PTSD. At T2, 6,6% still suffered from posttraumatic stress symptoms. The symptoms of the different victim categories clearly indicated the influence of the degree of exposure on the development of posttraumatic stress symptoms. Problems inherent to retrospective scientific research after a disaster are discussed.  相似文献   
49.

Purpose

Hospital-acquired bacterial pneumonia (HABP) is a critical concern in hospitals with ventilator-associated bacterial pneumonia (VABP) remaining the most common infection in the ICU, often due to Staphylococcus aureus, an increasingly difficult to treat pathogen. Anti-infective monoclonal antibodies (mAb) may provide new, promising treatment options. This randomized, double-blinded, placebo-controlled study aimed at assessing the safety and pharmacokinetics of AR-301, an S. aureus alpha toxin-neutralizing mAb, and exploring its clinical and microbiologic outcomes when used adjunctively with standard-of-care antibiotics.

Methods

Eligibility in this trial required microbiologically confirmed severe S. aureus pneumonia, including HABP, VABP or CABP, treated in the ICU and an APACHE II score ≤?30. Standard-of-care antibiotics selected by the investigators were administered to all patients in the study following clinical and microbiologic confirmation of S. aureus pneumonia. Adjunctive treatment of AR-301 was to start <?36 h after onset of severe pneumonia. AR-301 was administered to four sequentially ascending dose cohorts. The placebo cohort received antibiotics and a placebo buffer. Clinical outcomes were adjudicated by a blinded committee. S. aureus eradication was declared based on a negative follow-up culture and presumed to be negative when no culture was obtained in the presence of clinical improvement.

Results

Thirteen ICUs enrolled 48 patients, with pneumonia attributable to MRSA in six subjects. The study drug displayed a favorable safety profile: Of 343 AEs reported, 8 (2.3%) were deemed related, none serious. In a post hoc subgroup analysis of VABP patients receiving AR-301, ventilation duration was shorter for AR-301-treated patients compared with the placebo group. Overall, there was a trend toward a better and faster microbiologic eradication at day 28. The PK profile of AR-301 is consistent with that of a human IgG1 mAb, with a plasma half-life of about 25 days.

Conclusions

Adjunctive treatment of severe S. aureus HABP with anti-staphylococcal mAbs appears feasible and suggests some clinical benefits, but larger randomized studies are needed to better define its safety and efficacy.
  相似文献   
50.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号