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   1856篇
  免费   112篇
  国内免费   10篇
耳鼻咽喉   36篇
儿科学   149篇
妇产科学   60篇
基础医学   220篇
口腔科学   121篇
临床医学   143篇
内科学   398篇
皮肤病学   71篇
神经病学   100篇
特种医学   74篇
外科学   211篇
综合类   20篇
一般理论   1篇
预防医学   70篇
眼科学   97篇
药学   120篇
中国医学   7篇
肿瘤学   80篇
  2024年   6篇
  2023年   28篇
  2022年   45篇
  2021年   84篇
  2020年   68篇
  2019年   74篇
  2018年   59篇
  2017年   70篇
  2016年   93篇
  2015年   91篇
  2014年   107篇
  2013年   126篇
  2012年   157篇
  2011年   151篇
  2010年   94篇
  2009年   75篇
  2008年   92篇
  2007年   102篇
  2006年   122篇
  2005年   114篇
  2004年   89篇
  2003年   72篇
  2002年   34篇
  2001年   3篇
  2000年   2篇
  1999年   2篇
  1998年   7篇
  1997年   2篇
  1996年   1篇
  1995年   2篇
  1994年   2篇
  1992年   1篇
  1987年   1篇
  1986年   1篇
  1985年   1篇
排序方式: 共有1978条查询结果,搜索用时 15 毫秒
51.
52.
The regulation of glucose, lipid metabolism and immunoreactivities of insulin and glucagon peptides by delta-9-tetrahydrocannabinol (Δ9-THC) in diabetes were examined in an experimental rat model. Male Sprague-Dawley rats were divided into four groups: (1) control, (2) Δ9-THC treated, (3) diabetic, and (4) diabetic + Δ9-THC. The type 2 diabetic rat model was established by intraperitoneal (i.p.) injection of nicotinamide (85 mg/kg body weight) followed after 15 min by i.p. injection of streptozotocin (STZ) at 65 mg/kg of body weight. Δ9-THC and Δ9-THC treated diabetic groups received 3 mg/kg/day of Δ9-THC for 7 days. The immunolocalization of insulin and glucagon peptides was investigated in the pancreas using a streptavidin–biotin–peroxidase technique. High density lipoprotein cholesterol (HDL), low density lipoprotein cholesterol (LDL), very low density lipoprotein cholesterol (VLDL), triglycerides (TG), total cholesterol (TC) and total protein (TP) levels were measured in serum. Total islet area percent of insulin immunoreactive cells slightly changed in diabetic + Δ9-THC rats compared to diabetic animals. However, the area percent of glucagon immunoreactive cells showed a decrease in diabetic + Δ9-THC rats compared to that of diabetic animals alone. Serum TC, HDL and LDL levels of diabetes + Δ9-THC group showed a decrease compared to the diabetic group. These results indicate that Δ9-THC may serve a protective role against hyperlipidemia and hyperglycemia in diabetic rats.  相似文献   
53.
54.
Objective

We aimed to investigate the acute physiological responses (APR) to physiotherapy applications in patients undergoing autologous stem cell transplantation (ASCT), the difference between pre- and post-ASCT according to APR.

Methods

Twenty-six patients who were hospitalized for ASCT attended regular physiotherapy program. APR was recorded in the beginning and at the end of each exercise session. The differences in APR were calculated for each session. The mean values of the differences in APR were computed in pre-conditioning, pre-, and post-ASCT. Daily complete blood counts were also recorded during ASCT.

Results

Hemoglobin and platelet counts were significantly lower pre- and post-ASCT. Neutrophil counts were significantly lower post-ASCT. The difference in systolic blood pressure (SBP) in the beginning and at the end of the exercise sessions was significantly higher post-ASCT in comparison to pre-ASCT.

Conclusion

There was no significant change in APR except the SBP which suggests that similar level of exercise intensity could be tolerated in pre- and post-ASCT periods as well as preconditioning.  相似文献   

55.
Purpose: The aim of this study was to evaluate the fracture strength of experimental hollow and solid design zirconia dowels. Materials and Methods: Three types of dowels (fiber‐reinforced composite [FRC], hollow design, and solid design zirconia dowels) were tested in the study (n = 10). A three‐point bending method was conducted, and a load was applied until fracture. The values were recorded as Newtons (N) and then converted to megapascals (MPa) according to the diameter of the dowels. Statistical analyses were performed using one‐way ANOVA and Tukey HSD tests. The significance was set at p < 0.05. Results: The mean fracture strength of the hollow design zirconia dowels was significantly higher (960.72 MPa) than solid zirconia dowels (741.78 MPa) and FRC dowels (687.64 MPa) (p < 0.05). Conclusions: The hollow design zirconia dowel seems to have sufficient fracture strength for anterior restorations. This design may be beneficial to access the apical region when retreatment is necessary, without any dowel‐removing procedure.  相似文献   
56.
Nontransfusion-dependent thalassemia (NTDT) patients may develop iron overload and its associated complications despite receiving only occasional or no transfusions. The present 1-year, randomized, double-blind, placebo-controlled THALASSA (Assessment of Exjade in Nontransfusion-Dependent Thalassemia) trial assessed the efficacy and safety of deferasirox in iron-overloaded NTDT patients. A total of 166 patients were randomized in a 2:1:2:1 ratio to starting doses of 5 or 10 mg/kg/d of deferasirox or placebo. The means ± SD of the actual deferasirox doses received over the duration of the study in the 5 and 10 mg/kg/d starting dose cohorts were 5.7 ± 1.4 and 11.5 ± 2.9 mg/kg/d, respectively. At 1 year, the liver iron concentration (LIC) decreased significantly compared with placebo (least-squares mean [LSM] ± SEM, -2.33 ± 0.7 mg Fe/g dry weight [dw], P = .001, and -4.18 ± 0.69 mg Fe/g dw, P < .001) for the 5 and 10 mg/kg/d deferasirox groups, respectively (baseline values [means ± SD], 13.11 ± 7.29 and 14.56 ± 7.92 mg Fe/g dw, respectively). Similarly, serum ferritin decreased significantly compared with placebo by LSM -235 and -337 ng/mL for the deferasirox 5 and 10 mg/kg/d groups, respectively (P < .001). In the placebo patients, LIC and serum ferritin increased from baseline by 0.38 mg Fe/g dw and 115 ng/mL (LSM), respectively. The most common drug-related adverse events were nausea (n = 11; 6.6%), rash (n = 8; 4.8%), and diarrhea (n = 6; 3.6%). This is the first randomized study showing that iron chelation with deferasirox significantly reduces iron overload in NTDT patients with a frequency of overall adverse events similar to placebo.  相似文献   
57.
Objective. Characteristics of insomnia symptoms in Turkey are not well established. The goal of this study was to determine the prevalence of insomnia and related symptoms in an urban district of Turkey. Method. The study was carried out in Ankara, in an urban district with a population of 2665. Out of the 1332 people in the sample, 1034 in the 15–65 age range were included in the study. Interviews were conducted according to the “Sleep Disorders Assessment Questionnaire” developed by the researchers. The Insomnia Severity Index (ISI) was also given to the subjects with a sleep problem to measure the subjective quality and quantity of insomnia symptoms. Results and conclusion. A total of 29.4% of all participants reported a sleep problem, out of which 23.7% defined one or more of the insomnia symptoms which included difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), early morning awakening (EMA), non-restorative sleep (NRS) and sleep deprivation (SD). Insomnia risk was found to be significantly increased with age, female sex, smoking and chronic medical illness. A total of 75.9% of participants who reported insomnia symptoms did not seek medical help for their complaint. According to the ISI, among the subjects with insomnia symptoms, 79 (32.2%) had subthreshold insomnia, 43 (17.6%) had clinical insomnia, 12 (4.9%) had severe clinical insomnia, while 88 (35.9%) did not score in the range indicating insomnia. The findings are discussed in the light of previous research and in relation to sociocultural factors emphasizing the need for public education on sleep disorders as medical conditions.  相似文献   
58.
Tourette syndrome (TS) is a childhood onset neurodevelopmental disorder. Although it is widely accepted that genetic factors play a significant role in TS pathogenesis the etiology of this disorder is largely unknown. Identification of rare copy number variations (CNVs) as susceptibility factors in several neuropsychiatric disorders such as attention deficit‐hyperactivity disorder (ADHD), autism and schizophrenia, suggests involvement of these rare structural changes also in TS etiology. In a male patient with TS, ADHD, and OCD (obsessive compulsive disorder) we identified two microduplications (at 15q13.3 and Xq21.31) inherited from a mother with subclinical ADHD. The 15q duplication included the CHRNA7 gene; while two genes, PABPC5 and PCDH11X, were within the Xq duplication. The Xq21.31 duplication was present in three brothers with TS including the proband, but not in an unaffected brother, whereas the 15q duplication was present only in the proband and his mother. The structural variations observed in this family may contribute to the observed symptoms, but further studies are necessary to investigate the possible involvement of the described variations in the TS etiology. © 2013 Wiley Periodicals, Inc.  相似文献   
59.
60.
The aim of the study was to determine the association between birthweight, maternal medical history and acne, hirsutism, and menstrual disorder symptoms in Turkish adolescent population. Self-administered questionnaires were distributed to all volunteer female students at 15 secondary schools. The subjects' body mass index, birthweight, age at menarche, pattern of menstrual cycle, and presence of acne or hirsutism problems were recorded. Maternal obstetric parameters, menstrual cycle, presence of acne or hirsutism at present and at adolescent period were also asked. The impact of birthweight and maternal history on acne, hirsutism, and menstrual disorder symptoms was evaluated. The results of the study showed that after exclusion of subjects born prematurely, total of 1,309 students filled the questionnaires properly and included in the study. Of these students, 174 had low birthweight (LBW) (<2,500?g), 925 had appropriate (2,500-4,000?g), and 210 had high birthweight (>4,000?g). LBW students had higher incidence of menstrual disorder and acne problems (P?=?0.032 and P?=?0.011, respectively). Maternal acne and hirsutism problems were significantly often in LBW group. Multivariate analysis showed that LBW was a predictor of acne, hirsutism, and menstrual disorder at adolescent period (P?=?0.001; P?=?0.01, and 0.02, respectively). In addition, maternal menstrual disorder was also a predictor of menstrual disorder (P?=?0.035). We concluded that LBW is a good predictor of acne, hirsutism, and menstrual disorder problems in Turkish adolescent population.  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