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   9048篇
  免费   691篇
  国内免费   37篇
耳鼻咽喉   24篇
儿科学   251篇
妇产科学   200篇
基础医学   1607篇
口腔科学   73篇
临床医学   893篇
内科学   2055篇
皮肤病学   201篇
神经病学   1032篇
特种医学   247篇
外科学   931篇
综合类   16篇
一般理论   2篇
预防医学   768篇
眼科学   110篇
药学   610篇
中国医学   7篇
肿瘤学   749篇
  2024年   7篇
  2023年   94篇
  2022年   137篇
  2021年   306篇
  2020年   169篇
  2019年   218篇
  2018年   316篇
  2017年   184篇
  2016年   240篇
  2015年   288篇
  2014年   403篇
  2013年   506篇
  2012年   770篇
  2011年   760篇
  2010年   388篇
  2009年   416篇
  2008年   620篇
  2007年   651篇
  2006年   609篇
  2005年   664篇
  2004年   528篇
  2003年   529篇
  2002年   426篇
  2001年   47篇
  2000年   47篇
  1999年   73篇
  1998年   91篇
  1997年   67篇
  1996年   44篇
  1995年   37篇
  1994年   28篇
  1993年   22篇
  1992年   14篇
  1991年   12篇
  1990年   10篇
  1988年   3篇
  1987年   3篇
  1986年   6篇
  1984年   6篇
  1983年   5篇
  1982年   2篇
  1980年   5篇
  1979年   2篇
  1978年   3篇
  1973年   5篇
  1972年   2篇
  1962年   1篇
  1961年   2篇
  1946年   1篇
  1893年   1篇
排序方式: 共有9776条查询结果,搜索用时 15 毫秒
41.
Repair of isolated coarctation of the aorta by subclavian flap aortoplasty carries the disadvantage of impaired blood supply to the left arm. However, ligation of branches of the subclavian artery can be tolerated without manifest ischemia of the upper extremity. We report the case of a young man who suffered from left upper extremity ischemia 18 years after initial operation. Treatment consisted of carotid-subclavian bypass with good outcome. The surgical approach of coarctation by subclavian aortoplasty should be reserved for specific cases, and if this procedure is performed, ligation of branches of the subclavian artery should be minimized to increase inflow into the left brachial artery.  相似文献   
42.
Mutations in the VPS45 gene lead to a severe primary immune deficiency characterized by severe congenital neutropenia and primary myelofibrosis, leading to overwhelming infection and early death. This condition is exceedingly rare with only 16 patients previously reported, including four with successful hematopoietic stem cell transplantation. We review the pathophysiology underlying this condition and detail our approach to treatment, particularly vis‐à‐vis bone marrow transplantation and the challenges of transplanting into a diseased bone marrow niche. We provide an update on the progress of our three previously reported patients, and two additional patients transplanted at our center.  相似文献   
43.
Plant-derived polyphenols flavonoids are increasingly being recognized for their medicinal potential. These bioactive compounds derived from plants are gaining more interest in ameliorating adverse health risks because of their low toxicity and few side effects. Among them, therapeutic approaches demonstrated the efficacy of catechins, a major group of flavonoids, in reverting several aspects of Down syndrome, the most common genomic disorder that causes intellectual disability. Down syndrome is characterized by increased incidence of developing Alzheimer’s disease, obesity, and subsequent metabolic disorders. In this focused review, we examine the main effects of catechins on comorbidities linked with Down syndrome. We also provide evidence of catechin effects on DYRK1A, a dosage-sensitive gene encoding a protein kinase involved in brain defects and metabolic disease associated with Down syndrome.  相似文献   
44.
45.
46.
47.
This study explored the extent to which the psychological distress of women is related to their motherhood status. A representative sample of 6970 women, aged 20-59, living in France, was interviewed. This analysis was restricted to the 2799 women aged between 25 and 39, 307 of whom had had a baby in the last year. Several indicators of psychological distress were used, including the 12-item General Health Questionnaire, psychotropic drug use and suicide attempts. Women with babies under the age of 12 months presented no more psychological problems than the other women. The proportion of respondents with scores above 5 for the GHQ was 8.7% for mothers with young babies, 11.4% for mothers of an older child and 12.0% for childless women. Adjusting for age, education, employment and couple status, no differences were observed between the three groups of women, except for a lower level of psychotropic drug use among the mothers of young babies. Overall, regardless of maternal status, a high proportion of women showed symptoms of anxiety and depression. Thus, research and clinical efforts should focus on risk factors for psychological distress in women and on preventive measures beyond the post-partum period.  相似文献   
48.
OBJECTIVES: To evaluate the level of information and informed consent for maternal serum screening (MSS) for Down syndrome (DS) in the second trimester of pregnancy and analyse the exercise of autonomy towards the test by the women concerned. METHODS: We studied the population of pregnant women attending obstetric consultations in two French hospitals over a 3-month period. The women were assigned to three groups according to MSS results for DS: women at high risk of having a child with DS (group 1), women at low risk (group 2) and women who did not undergo the test (group 3). A questionnaire was completed before the medical consultation, to assess the quality of consent before amniocentesis for the group at high risk and before the second-trimester ultrasound scan for the other two groups. RESULTS: We analysed 305 questionnaires for 89, 137 and 79 women belonging to groups 1, 2 and 3 respectively. In total, 123 women (40.3% [IC 95%, 35-46%]) were considered to be well informed; 33 (10%, [IC 95%, 8-12%]) had a high level of knowledge, but made choices not consistent with their stated attitude, and 149 (49.7% [IC 95%, 45-56%]) were considered uninformed. Logistic regression analysis showed that maternal consent depended on three independent components: The score attributed to the doctor for information about MSS (t = 4.216, p < 0.001).Whether the patient belonged to group 1 (t = -2.631, p < 0.009).Educational level (< high-school diploma, high-school diploma or at least two years of higher education after high school) (t = 2.324, p < 0.02). The rate of consent increased with educational level and was highest for the women in group 1 and for those whose doctor had a high information score. CONCLUSIONS: Our findings clearly show that women are provided with insufficient information concerning MSS screening for DS in the second trimester of pregnancy for real and valid consent to be obtained.  相似文献   
49.
The implantation process, currently thought to be the most critical step in achieving a successful early pregnancy, remains one of the most important unsolved processes in reproductive medicine. It depends on uterine-dependent and embryo-specific events, which need to be critically coordinated. Early embryo signaling following a maternal hormonal or cytokine-mediated preparation phase seems to be involved in stages immediately before, during and just after the apposition step to permit adequate proliferation of the stroma. Our objective is to develop guidelines and diagnostic tools pertinent to appreciate uterine receptivity. We will focus our attention on the uterine luminal environment at the time of oocyte retrieval and on the monitoring of the endometrium using three-dimensional ultrasound associated with digital technology and cytokine quantification by real-time PCR during the implantation window in an IVF/ICSI population. There is an accumulating body of data which strongly suggests that both implantation and uterine receptivity are controlled, primarily, though not exclusively, by locally acting growth factors and cytokines, some under steroid control. Some specific cytokines (IL-12, IL-15 and IL-18) in the luminal environment and in the endometrium allow a distinct pattern of abnormal uterine receptivity. The identification of these distinct patterns of abnormal uterine receptivity and of the mechanisms leading to the abnormal angiogenesis before implantation strongly suggest that no single therapeutic scheme can correct all cases of implantation failure and should be adapted for each patient especially in the case of unexplained infertility.  相似文献   
50.
Background: Alongside metabolic diseases (esp. obesity), allergic disorders are becoming increasingly prevalent. Since both obesity and allergies are highly impacted by environmental determinants, with this study we assessed the potential link between metabolic implications and two distinct types of allergies. Methods: Using cross-sectional data from the German FoCus cohort, n = 385 allergy cases, either hay fever (=type I allergy, n = 183) or contact allergy (=type IV allergy, n = 202) were compared to age- and sex-matched healthy control subjects (1:1 ratio, in total n = 770) regarding their metabolic phenotype, diet, physical activity, sleep, gut microbial composition, and serum metabolite profile using suitable BMI-adjusted models. Results: Obesity and metabolic alterations were found significantly more prevalent in subjects with allergies. In fact, this relation was more pronounced in contact allergy than hay fever. Subsequent BMI-adjusted analysis reveals particular importance of co-occurring hyperlipidaemia for both allergy types. For contact allergy, we revealed a strong association to the dietary intake of poly-unsaturated fatty acids, particularly α-linolenic acid, as well as the enrichment of the corresponding metabolic pathway. For hay fever, there were no major associations to the diet but to a lower physical activity level, shorter duration of sleep, and an altered gut microbial composition. Finally, genetic predisposition for hyperlipidaemia was associated to both contact allergy and hay fever. Conclusions: Reflected by higher allergy prevalence, our findings indicate an impaired immune response in obesity and hyperlipidaemia, which is differentially regulated in type I and type IV allergies by an unfavourable lifestyle constellation and subsequent microbial and metabolic dysfunctions.  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