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   2320篇
  免费   98篇
  国内免费   9篇
耳鼻咽喉   52篇
儿科学   65篇
妇产科学   21篇
基础医学   267篇
口腔科学   163篇
临床医学   275篇
内科学   391篇
皮肤病学   9篇
神经病学   256篇
特种医学   79篇
外科学   271篇
综合类   6篇
一般理论   3篇
预防医学   170篇
眼科学   39篇
药学   292篇
肿瘤学   68篇
  2023年   12篇
  2022年   27篇
  2021年   37篇
  2020年   23篇
  2019年   31篇
  2018年   38篇
  2017年   46篇
  2016年   46篇
  2015年   46篇
  2014年   76篇
  2013年   148篇
  2012年   123篇
  2011年   147篇
  2010年   92篇
  2009年   97篇
  2008年   155篇
  2007年   164篇
  2006年   146篇
  2005年   166篇
  2004年   152篇
  2003年   142篇
  2002年   149篇
  2001年   29篇
  2000年   25篇
  1999年   29篇
  1998年   33篇
  1997年   20篇
  1996年   19篇
  1995年   15篇
  1994年   15篇
  1993年   16篇
  1992年   11篇
  1991年   14篇
  1990年   14篇
  1989年   11篇
  1988年   9篇
  1987年   8篇
  1986年   11篇
  1985年   7篇
  1984年   12篇
  1983年   6篇
  1982年   7篇
  1981年   10篇
  1980年   6篇
  1979年   5篇
  1978年   3篇
  1977年   14篇
  1976年   6篇
  1975年   2篇
  1973年   2篇
排序方式: 共有2427条查询结果,搜索用时 949 毫秒
71.
The purpose of the current study was to evaluate influences of radial tears and partial meniscectomy of lateral meniscus on the knee joint mechanics during normal walking by using computational modeling. A 3D geometry of a knee joint of a healthy patient was obtained from our previous study, whereas the data of normal walking were taken from the literature. Cartilage tissue was modeled as a fibril reinforced poroviscoelastic material, whereas meniscal tissue was modeled as a transverse isotropic elastic material. The realistic gait cycle data were implemented into the computational model and the effects of radial tears and partial meniscectemy of lateral meniscus on the knee joint mechanics were simulated. Middle, posterior, and anterior radial tears in lateral meniscus increased stresses by 300%, 430%, and 1530%, respectively, at the ends of tears compared to corresponding areas in the model with intact lateral meniscus. Meniscus tears did not alter stresses and strains at the tibial cartilage surface, whereas partial meniscectomy increased contact pressures, stresses, strains and pore pressures in the tibial cartilage by 50%, 44%, 21%, and 43%, respectively. Increased stresses and strains were observed primarily during the first ~50% of the stance phase of the gait cycle. The present study suggests that anterior radial tear causes the highest risk for the development of total meniscal rupture, whereas partial meniscectomy increases the risk for the development of OA in lateral tibial cartilage. Highest risks for meniscus and cartilage failures are suggested to occur during the loading response and mid‐stance of the gait cycle. In the future, the present modeling may be further developed to offer a clinical tool for aid in decision making of clinical interventions for patients with knee joint injuries. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1208–1217, 2013  相似文献   
72.
73.
The necessity for postoperative inhaled nitric oxide (NO) therapy and predictive factors for that need were retrospectively analysed in 457 paediatric patients at risk of pulmonary hypertensive events following open-heart surgery for congenital heart disease. Inhaled NO was given postoperatively to 46% of the study group and to 23% of all patients undergoing open-heart surgery during the study period. Factors associated with increased need for postoperative NO were age <1 year, Down's syndrome, preoperative pulmonary hypertension and increased pulmonary vascular resistance. Using a multivariate model based on these factors, 73% of the patients who were given NO were identified. Thus, in a setting with unrestricted access to NO therapy, almost half of the patients with cardiac lesions that commonly give rise to postoperative pulmonary hypertension were given postoperative NO. Seventy-three percent of postoperative NO treatment was associated with a relatively small number of pre- and perioperative patient-related risk factors.  相似文献   
74.
We report how scapholunate (SL) lesions found during arthroscopy were treated using a new palmar operation based on the use of a tendon loop formed using the palmaris longus tendon, with promising preliminary results. Scapholunate instability induced by hyperextension injury was diagnosed and graded arthroscopically. Volar capsuloplasty was then done by free tendon graft in the same session in 31 patients with grades II-IV scapholunate instability. Half of the patients operated on had a normal range of movement, and all except one had flexion-extension of at least 75% of the normal. Half of the patients had no pain or limitations of the use of the wrist, and although half the patients had some pain on exertion, not one had severe pain. These results are comparable to, or even better than, those reported using other methods of repair. The combined procedure saves money, diminishes the total recuperation time and, as autologous tissues are used for the repair, secondary operations for removal of the implant are unnecessary. This method seems to be a useful adjunct to the types of operative treatment available, although it is apparently not suitable in static grade IV SL instability.  相似文献   
75.
76.
The aim of this study was to investigate the prevalence of mental disorder and associated factors during an economic recession. Random samples of Finnish general population were collected in 3 consecutive years, 1993-95. The prevalence of mental disorders was assessed by means of the 12-item General Health Questionnaire (GHQ). The prevalence of mental disorders varied among Finnish men from 15.6% to 19.2% and among women from 21 to 24.5%. Mental disorder was more common among women than among men in every study year. Mental disorder was more common among the unemployed than among other respondents both in women and men in every year. Subjective poor health, suicidal thoughts and poor economic situation were constantly associated with mental disorder in both sexes every year. Using logistic regression analyses, problems with a partner, uncertain future orientation and use of psychoactive drugs, in particular, were found to be fairly permanent independent risk factors in relation to mental disorder. As studied by gender no major changes occurred in the mental health status of Finns during economic recession, although in many specific groups mental disorder was markedly more common than in the general population.  相似文献   
77.
Bipolar disorder is frequently connected to other psychiatric disorders. On the basis of The National Hospital Discharge Register in Finland, we studied the recorded prevalence of psychiatric comorbidity among bipolar inpatients by clinicians, and the factors that were associated with it. Of the 2687 hospital stays in 1998, 82% had no other recorded psychiatric diagnosis except an episode of bipolar disorder. Psychiatric comorbidity was recorded in 18% of hospital stays, of which 20% had two comorbid psychiatric diagnoses. Substance-related disorders (11%) were the most commonly recorded comorbid disorders. Personality disorders were recorded in 6%, and anxiety disorder in 1% of the hospital stays. These figures should be considered far below the expected ones. Recorded comorbidity was associated with the type of episode. Comorbidity in bipolar disorder in psychiatric hospitals in Finland seems to go greatly undetected and may have a deteriorating impact on the course of the illness.  相似文献   
78.
The objective of this population-based study was to determine whether traumatic experiences in general, and multiple traumatic experiences in particular, are associated with persistent self-rated depressive symptoms in adult Finnish subjects over 2?years of follow-up. The study sample included 1405 subjects aged 25–64?years. Subjects (n=217) who were depressed both at baseline in 1999 and on follow-up 2?years later in 2001 (having persistent depressive symptoms) were compared with subjects (n=987) having no depressive symptoms either at baseline or on follow-up. All six categories of traumatic experiences (wartime experience, natural disaster, life-threatening accident, victim of violent crime, domestic violence and childhood sexual abuse) pertained to the respondents’ whole life span. Odds ratios, adjusted for significant covariates, were obtained from multiple logistic regression models that estimated the likelihood of persistent depressive symptoms in different trauma categories. Persistent depressive symptoms had a significant positive graded relationship with the number of traumatic experiences. The adjusted odds of persistent depression was 6.05 (95% CI 1.76–20.7) for men and 6.99 (95% CI 2.69–18.2) for women in those with three or more traumatic experiences compared with those with no such experiences at all. Multiple traumatic experiences substantially increase the likelihood of persistent depressive symptoms. Mental health intervention, as early as possible, may serve to prevent the chronicity of depressive reactions among victims of multiple traumas.  相似文献   
79.
Abstract

Purpose: This study examined a developmental model that links affect-regulation difficulties in childhood with three dimensions of alexithymia in adolescence (difficulty identifying feelings, difficulty describing feelings, and externally oriented thinking) and substance use and depression in adulthood, while accounting for cumulative contextual risk in childhood, and testing potential gender moderation.

Methods: Multiple group path analyses were conducted using data from the Northern Finland Birth Cohort 1986 (N?=?6963). Analyses used data collected during prenatal/birth, childhood, adolescence, and young adulthood periods.

Results: Our examination of early precursors for alexithymia indicated that the associations of affect-regulation problems in childhood with alexithymia were stronger for girls, potentially putting girls with affect-regulation difficulties in childhood at higher risk for developing alexithymia in adolescence. The associations of cumulative contextual risk in childhood with alexithymia, substance use disorder, and depression diagnosis in adulthood were significant for both girls and boys. Our findings in regard to substance use and depression disorders revealed that alexithymia in adolescence predicted depression diagnosis in adulthood, particularly due to a contribution from the alexithymia domain of ‘difficulties identifying feelings.’ However, none of the alexithymia domains was directly associated with substance use disorder in adulthood.

Conclusions: Our study contributes to research that links alexithymia with difficulties in affect regulation and cumulative contextual risk in childhood, yielding findings that may be relevant for preventive interventions.  相似文献   
80.
ObjectivesCentral poststroke pain (CPSP), a neuropathic pain condition, is difficult to treat. Repetitive transcranial magnetic stimulation (rTMS) targeted to the primary motor cortex (M1) can alleviate the condition, but not all patients respond. We aimed to assess a promising alternative rTMS target, the secondary somatosensory cortex (S2), for CPSP treatment.Materials and MethodsThis prospective, randomized, double-blind, sham-controlled three-arm crossover trial assessed navigated rTMS (nrTMS) targeted to M1 and S2 (10 sessions, 5050 pulses per session at 10 Hz). Participants were evaluated for pain, depression, anxiety, health-related quality of life, upper limb function, and three plasticity-related gene polymorphisms including Dopamine D2 Receptor (DRD2). We monitored pain intensity and interference before and during stimulations and at one month. A conditioned pain modulation test was performed using the cold pressor test. This assessed the efficacy of the descending inhibitory system, which may transmit TMS effects in pain control.ResultsWe prescreened 73 patients, screened 29, and included 21, of whom 17 completed the trial. NrTMS targeted to S2 resulted in long-term (from baseline to one-month follow-up) pain intensity reduction of ≥30% in 18% (3/17) of participants. All stimulations showed a short-term effect on pain (17–20% pain relief), with no difference between M1, S2, or sham stimulations, indicating a strong placebo effect. Only nrTMS targeted to S2 resulted in a significant long-term pain intensity reduction (15% pain relief). The cold pressor test reduced CPSP pain intensity significantly (p = 0.001), indicating functioning descending inhibitory controls. The homozygous DRD2 T/T genotype is associated with the M1 stimulation response.ConclusionsS2 is a promising nrTMS target in the treatment of CPSP. The DRD2 T/T genotype might be a biomarker for M1 nrTMS response, but this needs confirmation from a larger study.  相似文献   
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