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   1122篇
  免费   54篇
  国内免费   5篇
耳鼻咽喉   10篇
儿科学   16篇
妇产科学   11篇
基础医学   130篇
口腔科学   13篇
临床医学   145篇
内科学   102篇
皮肤病学   7篇
神经病学   293篇
特种医学   12篇
外科学   63篇
综合类   1篇
预防医学   70篇
眼科学   6篇
药学   276篇
肿瘤学   26篇
  2023年   3篇
  2021年   13篇
  2020年   13篇
  2019年   15篇
  2018年   12篇
  2017年   12篇
  2016年   19篇
  2015年   11篇
  2014年   25篇
  2013年   47篇
  2012年   58篇
  2011年   64篇
  2010年   32篇
  2009年   40篇
  2008年   87篇
  2007年   89篇
  2006年   75篇
  2005年   75篇
  2004年   72篇
  2003年   66篇
  2002年   60篇
  2001年   18篇
  2000年   17篇
  1999年   29篇
  1998年   17篇
  1997年   9篇
  1996年   10篇
  1995年   17篇
  1994年   8篇
  1993年   9篇
  1992年   15篇
  1991年   14篇
  1990年   23篇
  1989年   12篇
  1988年   9篇
  1987年   10篇
  1986年   7篇
  1985年   5篇
  1984年   6篇
  1983年   9篇
  1982年   4篇
  1981年   4篇
  1980年   7篇
  1979年   4篇
  1978年   2篇
  1977年   2篇
  1976年   2篇
  1975年   4篇
  1974年   8篇
  1973年   5篇
排序方式: 共有1181条查询结果,搜索用时 46 毫秒
41.
The study compared health-related quality of life in 165 patients with major depression and 165 randomly selected and with age- and gender-matched controls from a population sample. Health-related quality of life was measured with the self-report questionnaire (RAND-36), which consists of eight dimensions. Overall, perceived quality of life was broadly reduced among depressive outpatients, and as compared with the control group, significant impairment was observed for all eight dimensions of health-related quality of life. Accompanying somatic diseases causing disability had no additional impact on the reduction of quality of life in depressive patients. Depression per se impairs an individual's functioning ability in a number of ways. It has a significant effect not only on mental well-being but also on perceived physical functioning and bodily pain, and even on general health perceptions. Major depression seems to explain the broad decline in the quality of life among depressive patients.  相似文献   
42.
Serum insulin and leptin levels in valproate-associated obesity   总被引:18,自引:4,他引:14  
PURPOSE: Weight gain is an important adverse effect of valproate (VPA) therapy, and it is associated with hyperinsulinemia and hyperandrogenism in women with epilepsy. Leptin is considered a signaling factor regulating body weight and energy metabolism. In human subjects, obesity is in general associated with elevated serum leptin levels, suggesting decreased sensitivity to leptin. The present study aimed at evaluating the role of insulin and leptin in VPA-related obesity. METHODS: Body mass index (BMI) was calculated, and serum insulin and leptin levels were measured in 81 patients with epilepsy taking VPA and in 51 healthy control subjects. RESULTS: Forty (49%) of the patients taking VPA and 25 (49%) of the control subjects were obese. The mean insulin levels were higher in VPA-treated patients than in the control subjects despite similar BMI values, when all subjects were included in the comparison. Both obese male and female patients taking VPA had higher serum insulin levels than the respective control subjects with similar BMI values. Serum insulin levels also were higher in lean male and lean female patients compared with the lean control subjects of same sex. Serum leptin levels did not differ between the VPA-treated patients and the control subjects. CONCLUSIONS: Both obese and lean patients taking VPA for epilepsy have hyperinsulinemia, suggesting development of insulin resistance. This may be one of the factors leading to weight gain during VPA treatment. However, the results of the present study do not suggest an independent role for leptin in the pathogenesis of VPA-related obesity.  相似文献   
43.
The purpose of this study was to test the hypothesis that traumatic brain injury (TBI) during childhood and adolescence is associated with psychiatric disorders, heavy alcohol use and criminal offenses in adulthood. We made use of an unselected, general population birth cohort (n=12058) in Northern Finland, which was followed up prospectively up to the age of 31. The data on TBIs of the cohort members were collected from the hospital case notes of the outpatient clinics of the hospitals in the region and from the Finnish Hospital Discharge Registers (FHDR). The data on mental disorders including alcohol diagnoses were also collected from the FHDR after a careful validation process. The Ministry of Justice provided information on criminal offenses for all subjects. The final number of subjects in our study was 5589 males and 5345 females. We found that after controlling for confounders, TBI during childhood or adolescence increased the risk of developing mental disorders two-fold (OR 2.1, 95% CI 1.1-3.6) and TBI was significantly related to later mental disorder with coexisting criminality in male cohort members (OR 4.1, 95% CI 1.2-13.6). The results support the TBI's association with psychiatric morbidity, which should not be overlooked when treating psychiatric patients, especially those with comorbid criminality.  相似文献   
44.
OBJECTIVE: The authors examined the association between self-reported depressive symptoms in adolescence and mental well-being in early adulthood. METHOD: A questionnaire assessing psychosocial well-being was given to a group of subjects (N=651) in their last 3 years of high school (mean age=16.8 years) and again when these subjects reached early adulthood (mean age=21.8 years). Diagnostic interview data were obtained from a subgroup of the young adults (N=245). Adolescents' depressive symptoms were analyzed in relation to their early adulthood mental health outcome data. RESULTS: Depressive symptoms in adolescence predicted early adulthood depressive disorders (major depression and dysthymia), comorbidity, psychosocial impairment, and problem drinking. CONCLUSIONS: Depressive symptoms in adolescence deserve attention as a potential risk for early adulthood mental disorders.  相似文献   
45.
Abstract During acute febrile diseases mild disturbances of water and electrolyte balance occur frequently. It has been suggested that changes in electrolyte balance, in particular hyponatraemia, might predispose a child to convulsions during febrile illness; however, the changes of electrolytes in the CSF are not known.We have studied the effects of fever and convulsions on water and electrolyte balance in CSF and serum by measuring osmolality and electrolyte concentrations in children. The febrile population consisted of 60 children, 36 of whom had seizures during fever. Twenty-one children without convulsions and nine children with epileptic symptoms were nonfebrile controls. We noticed that CSF is subject to changes in osmolality and electrolyte concentration during fever, while convulsions do not exhibit such changes. CSF osmolality and sodium concentrations were lower in febrile children than in nonfebrile controls. The osmolality in febrile children with convulsions was 3.8% (P<0.01) and without seizures 3.5% (P<0.01) lower than in nonfebrile nonconvulsive children. The changes in CSF sodium concentration, and to a lesser extent potasium and chloride concentrations, paralleled those of CSF osmolality. A positive correlation was observed between the CSF and serum osmolatities (r=0.73,P<0.0001), and sodium concentrations (r=0.63,P<0.0001). A negative correlation between the body temperature and both CSF osmolality (r=–0.66,P<0.0001) and sodium concentration (r=–0.59,P<0.0001) exhibits also the important regulative role of increased body tmeperature.Conclusion Fever is an important factor for disturbances in fluid and electrolyte balance. The alterations in CSF osmolality and sodium concentration do not, however, give an unambiguous explanation for the susceptibility to simple febrile seizures.  相似文献   
46.
Abstract: Plasma levels of diazepam and its metabolites were compared after a controlled release formulation and a regular tablet. Both gas chromatographic analysis of plasma diazepam and desmethyldiazepam and radioreceptor assay of total benzodiazepine activity were used. Also the concentrations of benzodiazepine in saliva samples were analyzed by radioreceptor assay. A typical initial plasma peak was seen after the regular tablet but not after the controlled release capsule. Hence the excessive initial sedation can be avoided and the risk of abuse reduced. Desmethyldiazepam increased for about two days after a single dose of diazepam. The receptor assay correlated in general with the sum of diazepam and its desmethyl derivative. The saliva assay gave about 2.5% of the plasma total benzodiazepine which correlates well with the expected free benzodiazepine. It seems that both the plasma radioreceptor assay and the saliva assay can be used to monitor the total benzodiazepine concentration.  相似文献   
47.
48.
In rats adapted to a +30°C temperature for one week, transfer to a temperature of +4°C increased immunoassayable serum TSH from 150–300 ng/ml 800–2000 ng/ml in 30 min. Since this response, as well as the level of serum TSH without stimulation, were decreased by reserpine, phentolamine, phenoxybenzamine, disulfiram and diethyldithiocarbamate, noradrenaline may be involved in the stimulation of TSH secretion. TRH-induced TSH increase was not blocked by reserpine.

1-Dopa, a noradrenaline precursor, decreased the TSH response to cold; -methyl-p-tyrosine increased the TSH level. Apomorphine decreased the level of serum TSH and inhibited the response to cold. The possibility of a dopaminergic inhibitory factor released from the hypothalamus is discussed. 5-HT has possibly a role in the acetylcholine is involved.  相似文献   

49.
This study aimed to reveal in general population the prevalence, associations, and statistical model of recurrent tinnitus by means of a mailed questionnaire. The study sample consisted of 1720 randomly selected adults who were classified into three subgroups: recurrent (once a month or more often), occasional (less often than once a month), and no tinnitus. According to age and gender standardized prevalence, recurrent tinnitus was reported in 15% of the sample. It was statistically highly significantly associated with earache, fullness of ears shoulder pain, the 25-years age group, and visits to a physician. The strongest predictor of recurrent tinnitus was fullness of ears followed by earache, shoulder ache, and temporomandibular disorder pain. We conclude that recurrent tinnitus seems to be quite common in adults and associated with earache and fullness of ears In patients with tinnitus without clinical findings, the examination of the stomatognathic system and cervical spine is recommended.  相似文献   
50.
Structural brain differences have been reported in many studies with schizophrenia, but few have involved a general population birth cohort. We investigated differences in volume, shape and laterality of hippocampus and amygdala in patients with schizophrenia, all psychoses and comparison subjects within a large general birth cohort sample, and explored effects of family history of psychosis, perinatal risk and age-at-onset of illness. All subjects with psychosis from the Northern Finland 1966 birth cohort were invited to a survey including MRI scan of the brain, conducted in 1999-2001. Comparison subjects not known to have psychosis were randomly selected from the same cohort. Volumes of hippocampus and amygdala were measured in 56 subjects with DSM-III-R schizophrenia, 26 patients with other psychoses and 104 comparison subjects. Small hippocampal volume reductions in schizophrenia (2%) and all psychoses (3%) were not significant when adjusted for total brain volume. The shape of hippocampus in schizophrenia did not differ significantly from comparison subjects. Right hippocampus and amygdala were significantly larger than the left in all groups. Mean amygdala volume in schizophrenia or all psychoses did not differ from comparison subjects. Patients with family history of psychosis had larger hippocampus than patients without. Neither perinatal risk nor age-at-onset of illness had any effect on hippocampal or amygdala volumes. Small hippocampal volume reduction in schizophrenia and all psychoses was not disproportionate to reduced whole brain volume in this population-based sample. Perinatal events that have been suggested as of etiological importance in structural pathology of psychosis had no effect.  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