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   1098篇
  免费   79篇
  国内免费   8篇
耳鼻咽喉   5篇
儿科学   18篇
妇产科学   14篇
基础医学   83篇
口腔科学   42篇
临床医学   79篇
内科学   240篇
皮肤病学   11篇
神经病学   122篇
特种医学   118篇
外科学   242篇
综合类   9篇
预防医学   35篇
眼科学   78篇
药学   50篇
肿瘤学   39篇
  2023年   6篇
  2022年   11篇
  2021年   12篇
  2020年   15篇
  2019年   21篇
  2018年   21篇
  2017年   7篇
  2016年   19篇
  2015年   22篇
  2014年   25篇
  2013年   46篇
  2012年   54篇
  2011年   84篇
  2010年   52篇
  2009年   47篇
  2008年   71篇
  2007年   61篇
  2006年   51篇
  2005年   37篇
  2004年   46篇
  2003年   37篇
  2002年   22篇
  2001年   11篇
  2000年   13篇
  1999年   11篇
  1998年   24篇
  1997年   39篇
  1996年   39篇
  1995年   24篇
  1994年   25篇
  1993年   21篇
  1992年   12篇
  1991年   17篇
  1990年   17篇
  1989年   21篇
  1988年   20篇
  1987年   17篇
  1986年   15篇
  1985年   12篇
  1984年   9篇
  1983年   18篇
  1982年   19篇
  1981年   15篇
  1980年   6篇
  1979年   3篇
  1978年   2篇
  1977年   1篇
  1976年   3篇
  1975年   2篇
  1970年   1篇
排序方式: 共有1185条查询结果,搜索用时 906 毫秒
31.
Definitive treatment of extended thoracic aortic dilatation is a major surgical challenge. Histopathology of resected thoracic aortic wall may reveal undiagnosed aortitis affecting outcome. We sought to investigate the benefit of thorough histopathology after one-stage corrective surgery for the treatment of extended thoracic aortic dilatation. Five patients underwent one-stage corrective surgery using the hybrid open arch repair by the frozen elephant trunk together with endovascular aortic grafting. A representative sample of the resected aortic arch was procured for histology. T- and B-lymphocytes, plasma cells, macrophages, and immunoglobulin G4 (IgG4) positivity were evaluated by immunohistochemistry. The mean preoperative maximum aortic diameter was 54 mm (range, 41–79 mm). The mean follow-up was 18 months (range, 1–24 months). As confirmed by computed tomography (CT) upon follow-up, complete thrombosis of the false lumen at the level of the frozen elephant trunk was achieved in all patients with dissection. One patient was operated due to atherosclerotic dilatation of the thoracic aorta, and postoperative CT showed successful exclusion of the atherosclerotic dilatation; this 75-year-old man was diagnosed with IgG4-positive aortitis and experienced unexpected blindness after surgery without evidence of emboli or long-term neurological impairment upon repeated brain CT. The hybrid open arch repair by the frozen elephant trunk and simultaneous endovascular repair is a feasible choice for one-stage surgery through sternotomy aiming at definitive treatment of extended thoracic aortic pathology. However, systematic evaluation of inflammation may reveal concealed aortitis affecting postoperative outcome and need for long-term surveillance.  相似文献   
32.
33.
Background: The need of an animal model of alcoholism becomes apparent when we consider the genetic diversity of the human populations, an example being dopamine D2 receptor (DRD2) expression levels. Research suggests that low DRD2 availability is associated with alcohol abuse, while higher DRD2 levels may be protective against alcoholism. This study aims to establish whether (i) the ethanol‐consuming mouse is a suitable model of alcohol‐induced brain atrophy and (ii) DRD2 protect the brain against alcohol toxicity. Methods: Adult Drd2+/+ and Drd2?/? mice drank either water or 20% ethanol solution for 6 months. At the end of the treatment period, the mice underwent magnetic resonance (MR) imaging under anesthesia. MR images were registered to a common space, and regions of interest were manually segmented. Results: We found that chronic ethanol intake induced a decrease in the volume of the temporal and parietal cortices as well as the caudal thalamus in Drd2?/? mice. Conclusions: The result suggests that (i) normal DRD2 expression has a protective role against alcohol‐induced brain atrophy and (ii) in the absence of Drd2 expression, prolonged ethanol intake reproduces a distinct feature of human brain pathology in alcoholism, the atrophy of the temporal and parietal cortices.  相似文献   
34.
35.
This study aimed to systematically evaluate the evidence-based literature on fast-track laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic adjustable gastric banding (LAGB) to determine the feasibility and safety of fast-track laparoscopic bariatric surgery. A literature search of PubMed, EMBASE and Cochrane Library using the MeSH terms “bariatric surgery”, “ambulatory surgical procedures” and related terms as keywords was performed. The study included articles that reported on intended next-day discharge for LRYGB and same-day discharge for LAGB. Data were extracted on study design and size, patient demographics, patient-selection criteria, patient preparation, perioperative management, operative details, clinical outcomes, and follow-up. The review included 13 studies classified as level 3b or 4 evidence. There were seven studies that investigated LAGB, five studies investigated LRYGB and one study detailed outcomes from both LRYGB and LAGB. Next-day discharge rate ranged from 81 to 100 % for LRYGB. Same-day discharge rate ranged from 76 to 98 % for LAGB. In LRYGB and LAGB complication, re-admission and mortality rates (≤10.5, ≤7.5, ≤0.1 %, respectively) were comparable with the conventional perioperative care. From our results, the fast-track management of patients undergoing LRYGB and LAGB is feasible. With careful patient selection and preparation within high-volume centres, and application of care pathways including close outpatient follow-up, outcomes for fast-track bariatric procedures can compare favourably with those reported in the literature for standard management, but with decreased cost. However, further studies from independent researchers are required to determine the safety of a generalised adoption of this approach outside of dedicated bariatric units, and to formally demonstrate the cost-benefit of fast-track bariatric surgery.  相似文献   
36.
The Zucker rat is used as a model of genetic obesity, and while Zucker rats have been well studied for their reduced sensitivity to leptin signaling and subsequent weight gain, little work has examined their responses to environmental signals that are associated with “hedonic” feeding. This study evaluated the effects of a high‐fat food olfactory cue (bacon) in stimulating nose‐poke food‐seeking behavior on first exposure (novel) and after a period of access for consumption (familiar) in lean and obese Zucker rats at either 4 or 12 months of age, and under ad‐lib fed (unrestricted; U) or chronically food‐restricted (70% of ad‐lib; R) conditions. Baseline nose‐poke levels were comparable amongst all groups. At 4 months of age, only ObU rats displayed increased behavioral activation to familiar food cues. Twelve‐month‐old Ob rats, regardless of diet, exhibited substantially greater food‐seeking behavior when exposed to both the novel and familiar olfactory cues. A strong positive correlation between body weight and nose‐poke entries for the familiar food cue was observed at both ages, while this correlation for the novel food cue was significant in 12–month‐old rats only. Similarly, there were strong positive correlations between food intake and poke entries for the familiar food cue was observed at both ages, while this correlation for the novel food cue was significant in 12–month‐old rats only. Although it is possible that differences in olfactory sensitivity contribute to these behavioral effects, our findings support the interactions between food intake, obesity, and food‐seeking behavior and are consistent with leptin inhibiting the brain's reactivity to food cues and suggest that the enhanced sensitivity to the food cues with leptin deficiency is likely to contribute to overeating and weight gain. Synapse, 2013. © 2012 Wiley Periodicals, Inc.  相似文献   
37.
38.
Modulation of reactive oxygen and nitrogen species in a tumor could be exploited for nanotherapeutic benefits. We investigate the antitumor effect in Walker-256 carcinosarcoma of magnetic nanodots composed of doxorubicin-loaded Fe3O4 nanoparticles combined with electromagnetic fields. Treatment using the magnetic nanodot with the largest hysteresis loop area (3402 erg/g) had the greatest antitumor effect with the minimum growth factor 0.49 ± 0.02 day–1 (compared to 0.58 ± 0.02 day–1 for conventional doxorubicin). Electron spin resonance spectra of Walker-256 carcinosarcoma treated with the nanodots, indicate an increase of 2.7 times of free iron (that promotes the formation of highly reactive oxygen species), using the nanodot with the largest hysteresis loop area, compared to conventional doxorubicin treatment as well as increases in ubisemiquinone, lactoferrin, NO-FeS-proteins. Hence, we provide evidence that the designed magnetic nanodots can modulate the tumor redox state. We discuss the implications of these results for cancer nanotherapy.  相似文献   
39.
The prevalence of posttraumatic stress disorder (PTSD) as it relates to individuals’ experiences of the COVID-19 pandemic has yet to be determined. This study was conducted to determine rates of COVID-19–related PTSD in the Irish general population, the level of comorbidity with depression and anxiety, and the sociodemographic risk factors associated with COVID-19–related PTSD. A nationally representative sample of adults from the general population of the Republic of Ireland (N = 1,041) completed self-report measures of all study variables. The rate of COVID-19–related PTSD was 17.7% (n = 184), 95% CI [15.35%, 19.99%], and there was a high level of comorbidity with generalized anxiety (49.5%) and depression (53.8%). Meeting the diagnostic requirement for COVID-19–related PTSD was associated with younger age, male sex, living in a city, living with children, moderate and high perceived risk of COVID-19 infection, and screening positive for anxiety or depression. Posttraumatic stress symptoms related to the COVID-19 pandemic are common in the general population. Our results show that health professionals responsible for responding to the COVID-19 pandemic should expect to routinely encounter symptoms and concerns related to posttraumatic stress.  相似文献   
40.
The 11th revision of the World Health Organization's International Classification of Diseases (ICD-11) includes a new disorder, complex posttraumatic stress disorder (CPTSD). The network approach to psychopathology enables investigation of the structure of disorders at the symptom level, which allows for analysis of direct symptom interactions. The network structure of ICD-11 CPTSD has not yet been studied, and it remains unclear whether similar networks replicate across different samples. We investigated the network models of four different trauma samples that included a total of 879 participants (M age = 47.17 years, SD = 11.92; 59.04% women) drawn from Austria, Lithuania, and Scotland and Wales in the United Kingdom. The International Trauma Questionnaire was used to assess symptoms of ICD-11 CPTSD in all samples. The prevalence of PTSD and CPTSD ranged from 23.7% to 37.3% and from 9.3% to 53.1%, respectively. Regularized partial correlation networks were estimated and the resulting networks compared. Despite several differences in the symptom presentation and cultural background, the networks across the four samples were considerably similar, with high correlations between symptom profiles (ρs = .48–.87), network structures (ρs = .69–.75), and centrality estimates (ρs = .59–.82). These results support the replicability of CPTSD network models across different samples and provide further evidence about the robust structure of CPTSD. The most central symptom in all four sample-specific networks and the overall network was “feelings of worthlessness.” Implications of the network approach in research and practice are discussed.  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