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   72252篇
  免费   9982篇
  国内免费   185篇
耳鼻咽喉   1014篇
儿科学   2010篇
妇产科学   1750篇
基础医学   7588篇
口腔科学   2022篇
临床医学   9649篇
内科学   16764篇
皮肤病学   1134篇
神经病学   5538篇
特种医学   2429篇
外科学   11085篇
综合类   804篇
现状与发展   2篇
一般理论   57篇
预防医学   8918篇
眼科学   1494篇
药学   4234篇
  1篇
中国医学   53篇
肿瘤学   5873篇
  2023年   1319篇
  2022年   722篇
  2021年   1795篇
  2020年   1822篇
  2019年   1476篇
  2018年   2380篇
  2017年   2095篇
  2016年   2413篇
  2015年   2557篇
  2014年   3688篇
  2013年   4581篇
  2012年   4441篇
  2011年   4453篇
  2010年   3175篇
  2009年   3336篇
  2008年   3953篇
  2007年   4007篇
  2006年   4195篇
  2005年   3714篇
  2004年   3403篇
  2003年   3183篇
  2002年   2994篇
  2001年   1140篇
  2000年   1066篇
  1999年   1074篇
  1998年   949篇
  1997年   762篇
  1996年   715篇
  1995年   707篇
  1994年   580篇
  1993年   511篇
  1992年   653篇
  1991年   577篇
  1990年   610篇
  1989年   551篇
  1988年   499篇
  1987年   425篇
  1986年   442篇
  1985年   474篇
  1984年   413篇
  1983年   342篇
  1982年   272篇
  1981年   244篇
  1980年   231篇
  1979年   252篇
  1978年   251篇
  1977年   205篇
  1974年   220篇
  1973年   203篇
  1972年   203篇
排序方式: 共有10000条查询结果,搜索用时 140 毫秒
101.
Background contextLumbar discectomy is the most common type of back surgery performed in the United States. Outcomes after this procedure can be variable and it appears that Workers' Compensation patients might be at increased risk for poor outcomes.PurposeTo examine long-term multidimensional outcomes of lumbar discectomy within a cohort of Workers' Compensation patients from Utah and identify presurgical biopsychosocial factors related to poor outcomes.Study design/settingA retrospective cohort study consisting of a review of presurgical medical records and assessment of patient outcomes via a telephone survey. Outcomes were assessed at least 2 years postsurgery.Patient sampleA consecutive sample of 271 workers from Utah who underwent lumbar discectomy from 1994 to 1999. A total of 134 patients were surveyed at the time of follow-up.Outcome measuresPatient satisfaction, Roland-Morris Disability Questionnaire, SF-36v2, and Stauffer-Coventry Index.MethodsA retrospective review of presurgical biopsychosocial variables and outcome assessment via telephone survey was conducted.ResultsWork disability rate for the cohort was 12.7% (17/134). Analysis of patient satisfaction, back pain-related dysfunction, and the Short-Form Health Survey-36 subscales indicated approximately 25% of patients experienced poor outcomes. Older age, number of comorbid health conditions, assigned case manager, litigation, and time delay from injury to surgery were consistently statistically significant predictors (p<.05) of poor outcomes.ConclusionsResults of this study suggest that compensated back surgery patients are at greater risk for poor lumbar discectomy outcomes than noncompensation patients. Presurgery correlates of poor outcomes may be useful in identifying high-risk compensation patients.  相似文献   
102.
Insulin-like growth factor-1 (Igf-1), a critical mediator of tissue repair, is significantly decreased in diabetic wounds. Furthermore, decreased levels of hypoxia-inducible factor 1-alpha (Hif-1alpha) and its target genes are also associated with impaired wound healing in diabetic mice. The aim of our study was to examine whether the reduced levels of Igf-1 are responsible for the reduction in Hif-1alpha protein synthesis and activity in diabetic wounds. We provide evidence that Igf-1 regulates Hif-1alpha protein synthesis and activity during wound repair. In addition, Igf-1 stimulated phosphytidylinositol 3-kinase activity in diabetic fibroblasts, which, in turn, increased activation of the translational regulatory protein, p70 S6 kinase. Moreover, improved healing of diabetic wounds by addition of recombinant IGF-1 protein was associated with an increase in Hif-1alpha protein synthesis and function in vivo.  相似文献   
103.
As the proportion of racial, ethnic, and cultural minorities in the United States continues to expand, pediatric emergency medicine providers are increasingly likely to encounter cultural and language barriers in practice. This paper reviews a conceptual framework encompassing the decision to seek emergency care, the process of providing such care, and the adherence to treatment plans and follow-up. The ways in which cultural and language barriers can negatively impact each element of this model are discussed in detail. Specific examples include provider ignorance of dangerous folk beliefs, communication barriers secondary to inappropriate interpreter use, and discriminatory assumptions regarding child abuse, pain management, and sexual activity. The practitioner is then provided with concrete recommendations to reduce these negative effects.  相似文献   
104.
105.
Internal hernia, the protrusion of a viscus through a peritoneal or mesenteric aperture, is a rare cause of small bowel obstruction. We report the clinical presentation, surgical management, and outcomes of one of the largest series of nonbariatric internal hernias. Ten-year retrospective review of patients at our institution yielded 49 cases of internal hernias. Majority of patients presented with symptoms of acute (75%) or intermittent (22%) small bowel obstruction. While 16% of CT scans were suspicious for internal hernia, in no cases the preoperative diagnosis of internal hernia was made. The most frequent internal hernias were transmesenteric (57.0%) and 34 hernias (69%) were caused by previous surgery. All internal hernias were reduced and the defects were repaired. Compromised bowel was present in 22 cases and 11 patients underwent small bowel resection. The mean postoperative hospitalization was 10.9 days. The overall mortality rate from our series is 2%, and the morbidity rate is 12%. Transmesenteric hernias, as complications of previous surgeries, are the most prevalent internal hernias. Preoperative diagnosis of internal hernia is extremely difficult because of the nonspecific clinical presentation. However, if discovered promptly, internal hernias can be repaired with acceptable morbidity and mortality. Poster presentation at Digestive Disease Week, May 22, 2006, Los Angeles, California, USA.  相似文献   
106.
BACKGROUND: The impact of infection with Burkholderia gladioli in cystic fibrosis, other chronic airway diseases and immunosuppressed patients is unknown. METHODS: A six-year retrospective review of all patients with B. gladioli infection was performed in a tertiary referral center with cystic fibrosis and lung transplantation programs. In addition, a targeted survey of all 251 lung transplant recipients was performed. Available B. gladioli isolates were analyzed via pulsed field gel electrophoresis. RESULTS: Thirty-five patients were culture positive for B. gladioli, including 33 CF patients. No bacteremia was identified. Isolates were available in 18 patients and all were genetically distinct. Two-thirds of these isolates were susceptible to usual anti-pseudomonal antibiotics. After acquisition, only 40% of CF patients were chronically infected (> or =2 positive cultures separated by at least 6 months). Chronic infection was associated with resistance to > or =2 antibiotic groups on initial culture and failure of eradication after antibiotic therapy. The impact of acquisition of B. gladioli infection in chronic infection was variable. Three CF patients with chronic infection underwent lung transplantation. One post-transplant patient developed a B. gladioli mediastinal abscess, which was treated successfully. CONCLUSIONS: The majority of patients' culture positive for B. gladioli at our center have CF. B. gladioli infection is often transient and is compatible with satisfactory post-lung transplantation outcomes.  相似文献   
107.
108.
INTRODUCTION: Limited access to medical care has resulted in large numbers of patients seeking primary care for non-emergent emergency conditions in emergency departments. This influx of patients is contributing to overcrowding and delays in care for patients with emergencies. In response, a system was implemented in which persons with non-emergent medical conditions, following a medical screening examination, did not receive further ED assessment or treatment and instead were referred to community resources. The purpose of this study was to describe the characteristics of individuals who were referred to community-based services, their condition after 72 hours, and their use of follow-up health care services. METHODS: All referred cases (n=225) were reviewed for chief complaint and demographics. Phone contact was attempted after 72 hours to determine the person's condition and if community resources were utilized. RESULTS: Of the 225 cases, 52% were female, with a mean age of 33 years. Their most common chief complaints were extremity problems (16%), toothache (9%), and medication refill (8%). Follow-up phone contact was successful with 82 people (37%) an average of 14 days after their ED visit. The majority (55%) reported their condition had improved; 39%were unchanged, and 6% were worse. Thirty-one people(40%) accessed community resources and 8 (26%) returned to another emergency department. No clinically significant associations were found between patient demographics and use of community resources. DISCUSSION: Most people who were successfully contacted for follow-up and who had come to the emergency department with non-emergent chief complaints did not access community resources and their condition frequently improved. Additional studies, with improved follow-up, are needed before suggesting that referring individuals to community resources is an acceptable practice.  相似文献   
109.
110.
The purpose of this study was to determine if changes in hindlimb motoneuron membrane electrical properties occur 4–6 months after spinal transection in the adult animal. Eight acute and nine chronic animals were spinalized at T12. Intracellular recordings from motoneurons innervating the triceps surae were performed. Membrane electrical properties, including resting potential, action potential peak amplitude, afterhyperpolarization duration, rheobasic current, input resistance and axonal conduction velocity were measured. There were no statistical differences found between group means or frequency distributions in the membrane properties of motoneurons assessed from acute and chronic spinal animals. Thus, alteration of motoneuron membrane properties does not appear to be a major contributing factor to the hyperexcitable hindlimb reflex activity demonstrated by chronic spinal animals.  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