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   7629篇
  免费   430篇
  国内免费   44篇
耳鼻咽喉   81篇
儿科学   195篇
妇产科学   184篇
基础医学   1098篇
口腔科学   321篇
临床医学   625篇
内科学   1325篇
皮肤病学   118篇
神经病学   807篇
特种医学   510篇
外科学   1120篇
综合类   40篇
一般理论   2篇
预防医学   400篇
眼科学   205篇
药学   529篇
中国医学   14篇
肿瘤学   529篇
  2023年   44篇
  2022年   113篇
  2021年   210篇
  2020年   148篇
  2019年   174篇
  2018年   185篇
  2017年   170篇
  2016年   231篇
  2015年   255篇
  2014年   315篇
  2013年   459篇
  2012年   598篇
  2011年   587篇
  2010年   352篇
  2009年   312篇
  2008年   507篇
  2007年   501篇
  2006年   446篇
  2005年   419篇
  2004年   363篇
  2003年   355篇
  2002年   335篇
  2001年   63篇
  2000年   45篇
  1999年   59篇
  1998年   55篇
  1997年   41篇
  1996年   54篇
  1995年   50篇
  1994年   42篇
  1993年   29篇
  1992年   32篇
  1991年   25篇
  1990年   15篇
  1989年   24篇
  1988年   18篇
  1987年   28篇
  1986年   24篇
  1985年   30篇
  1984年   27篇
  1983年   23篇
  1982年   28篇
  1981年   21篇
  1980年   19篇
  1979年   15篇
  1978年   17篇
  1977年   19篇
  1974年   19篇
  1971年   16篇
  1967年   17篇
排序方式: 共有8103条查询结果,搜索用时 15 毫秒
1.
Introduction: Allergic rhinitis is a common condition with increasing prevalence and is associated with several comorbid disorders such as bronchial asthma and atopic dermatitis. If allergen avoidance is not possible, allergen-specific immunotherapy is the only causal treatment option.

Areas covered: This review focuses on current treatments and the future outlook for allergic rhinitis. Pharmacotherapy includes mast cell stabilizers, antihistamines, glucocorticosteroids (GCSs), leukotriene receptor antagonists, and nasal decongestants. Nasal GCSs are currently regarded as the most effective treatment and are considered first-line therapy together with non-sedating antihistamines. The new formulation MP29-02 combines the nasal GCS fluticasone propionate with azelastine in one single spray and has achieved greater improvements than those under monotherapy with modern GCSs or antihistamines. Furthermore, this review discusses allergen immunotherapy alone and in combination with modern monoclonal antibodies.

Expert opinion: Despite the variety of medications for allergic rhinitis, ranging from general symptomatic agents like GCSs or decongestants, to more specific ones like histamine receptor or leukotriene blockers, to causal therapy like immunotherapy, many patients still experience treatment failures or unsatisfactory results. The ultimate goal may be to endotype every downstream pathway separately in order to offer patients individualized, targeted therapy with specific antibodies against the respective pathway.  相似文献   

2.
The study explored the counterfactual thinking that women with chronic and widespread pain showed in response to what they themselves considered to be particularly stressful situations. Counterfactual thinking in 125 women sick‐listed due to chronic and widespread pain was investigated in terms of structure, function and control focus. The women were asked, for each of three types of problems that they indicated in a questionnaire to affect them most strongly, to describe a typical occurrence of it and to complete a counterfactual sentence in connection with it of the type ‘If only . . .’. The majority of counterfactuals pertained to predominantly somatic problems (e.g. musculo‐skeletal problems, pain and fatigue) classified as being affective rather than preparative and self‐focused rather than external, whereas in counterfactuals relating to predominantly psychological/psychosocial problems a preparative function and an external focus were more prominent. The numbers of problems listed and the numbers of situations responded to counterfactually were positively correlated. The counterfactuals, although often related to somatic problems, generally concerned psychological or psychosocial matters such as finances and paid or unpaid work. A contextual approach to elucidating counterfactual thinking based on subjects' own experiences is seen as providing valuable insight into what bothers them most. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
3.
OBJECTIVES: Intraoperative cone-beam computerized tomography (CBCT) imaging has been introduced in oral and maxillofacial surgery. Using midfacial fractures as the pioneer model, this study describes the spectrum of further promising clinical indications for intraoperative CBCT and a clinical combination with intraoperative navigation. STUDY DESIGN: One hundred seventy-nine patients admitted for surgical treatment of the facial skeleton were included in the study. Intraoperatively, 3-dimensional images were generated with the mobile CBCT scanner Arcadis Orbic 3D, obtained from Siemens Medical Solutions, in a variety of indications. RESULTS: The acquisition of the data sets was uncomplicated, and image quality was sufficient to assess the postoperative result in all cases. In the example of a facial gunshot injury, a navigation system for intraoperative localization of the metal foreign bodies was used.  相似文献   
4.
Glycation (nonenzymatic glucosylation) of collagen may play a role in the primary pathology of the vitreous in diabetes. The extent of glycation is determined by the glucose concentration in the tissue. In this study glucose concentration was assayed in blood and vitreous samples obtained from three patient groups undergoing vitrectomy: nondiabetic patients (ND), diabetic patients with insulin-dependent diabetes mellitus (IDDM) and diabetic patients with non-insulin-dependent diabetes mellitus (NIDDM). In the ND group the glucose concentration in the vitreous (3.5 +- 1.8 mM/1) was always lower than in the blood (9.1 +- 3.5 mM/1). In the diabetic groups the vitreous glucose concentration was, with a few exceptions, generally lower than the blood glucose concentration. The vitreous glucose concentration in these groups was generally higher (IDDM 9.4+-3.3 mM/1, NIDDM 7.2+-3.9 mM/1) than in the ND group, and in 15 specimens exceeded 11 mM/1, a level increasing the probability of collagen glycation in the vitreous of diabetic patients.This study was given financial support by the Herman Järnhardt Foundation, the Inez and Joel Carlsson Foundation and by Diabetesföreningen in Malmö  相似文献   
5.
6.
7.
Prolonged physical exercise is associated with multiple changes in blood hemostasis. Eccentric muscle activation induces microtrauma of skeletal muscles, inducing an inflammatory response. Since there is a link between inflammation and coagulation we speculated that downhill running strongly activates the coagulation system. Thirteen volunteers participated in the Tyrolean Speed Marathon (42,195 m downhill race, 795 m vertical distance). Venous blood was collected 3 days (T1) and 3 h (T2) before the run, within 30 min after finishing (T3) and 1 day thereafter (T4). We measured the following key parameters: creatine kinase, myoglobin, thrombin-antithrombin complex, prothrombin fragment F1 + 2, D-dimer, plasmin-alpha(2)-antiplasmin complexes, tissue-type plasminogen activator antigen, plasminogen-activator-inhibitor-1 antigen and thrombelastography with ROTEM [intrinsic pathway (InTEM) clotting time, clot formation time, maximum clot firmness, alpha angle]. Thrombin generation was evaluated by the Thrombin Dynamic Test and the Technothrombin TGA test. Creatine kinase and myoglobin were elevated at T3 and further increased at T4. Thrombin-antithrombin complex, prothrombin fragment F1 + 2, D-dimer, plasmin-alpha(2)-antiplasmin complexes, tissue-type plasminogen activator antigen and plasminogen-activator-inhibitor-1 antigen were significantly increased at T3. ROTEM analysis exhibited a shortening of InTEM clotting time and clot formation time after the marathon, and an increase in InTEM maximum clot firmness and alpha angle. Changes in TGA were indicative for thrombin generation after the marathon. We demonstrated that a downhill marathon induces an activation of coagulation, as measured by specific parameters for coagulation, ROTEM and thrombin generation assays. These changes were paralleled by an activation of fibrinolysis indicating a preserved hemostatic balance.  相似文献   
8.
OBJECTIVE: Although somatoform disorders are assumed to be chronic clinical conditions, epidemiological knowledge on their natural course based on representative samples is not available. METHOD: Data come from a prospective epidemiologic study of adolescents and young adults in Munich, Germany. Respondents' diagnoses (N = 2548) at baseline and follow-up on average 42 months later are considered. The follow-up incidence, stability as well as selected baseline risk factors (sociodemographics, psychopathology, trauma exposure) for the incidence and stability of somatoform disorders and syndromes are prospectively examined. Diagnostic information was assessed by using the standardized Munich-Composite International Diagnostic Interview (M-CIDI). RESULTS: Over the follow-up period, incidence rate for any of the covered somatoform diagnoses was 25.7%. Stability for the overall group of any somatoform disorder/syndrome was 48%. Female gender, lower social class, the experience of any substance use, anxiety and affective disorder as well as the experience of traumatic sexual and physical threat events predicted new onsets of somatoform conditions, while stability was predicted by being female, prior existing substance use, affective and eating disorders as well as the experience of a serious accident. CONCLUSIONS: At least for a substantial proportion of individuals, the overall picture of somatization seems to be relatively stable, but with fluctuation in the symptom picture over time. Being female, the experience of substance use as well as anxiety disorder seem to constitute risk factors for the onset of new somatoform conditions as well as for a stable course over time.  相似文献   
9.
The effects of the serotonin-releasing compound p-chloroamphetamine (PCA, 2.5 mg/kg) on avoidance acquisition, retention and memory retrieval were examined in male Sprague-Dawley rats using a one-way active avoidance and a one-trial passive avoidance task. The drug was injected IP prior to training, following acquisition and prior to the retention test 24 hr after training using a state-dependent design. In the normal context situation pretraining administration of PCA markedly impaired active avoidance acquisition, but PCA-treated rats did not differ from controls in their retention performance when tested 24 hr after training. In the dark/light box test pretraining administration of PCA caused a dose-dependent impairment of both active and passive avoidance retention which could not be explained in terms of changes in locomotor activity or behavioural disinhibition at the time of testing or state-dependent retention. Post-training administration of PCA failed to affect avoidance retention in both tasks. The drug was found to impair memory retrieval in a dose- and time-dependent fashion in the one-way active but not in the passive avoidance test. Pretraining administration of PCA produced a progressive loss of passive and active avoidance performance at increasingly longer retention intervals. The present results suggest that serotonin has dual effects on processes underlying learning and memory involving effects on both associative and non-associative learning processes in the rat. The time-dependent loss of memory retention following 5-HT release indicates that serotonin has a role in the way information is processed in the brain.  相似文献   
10.
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