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   45514篇
  免费   2735篇
  国内免费   258篇
耳鼻咽喉   389篇
儿科学   1307篇
妇产科学   1212篇
基础医学   6011篇
口腔科学   950篇
临床医学   4533篇
内科学   9938篇
皮肤病学   887篇
神经病学   4837篇
特种医学   1525篇
外科学   5981篇
综合类   178篇
一般理论   19篇
预防医学   3398篇
眼科学   772篇
药学   2801篇
  1篇
中国医学   85篇
肿瘤学   3683篇
  2024年   70篇
  2023年   522篇
  2022年   1006篇
  2021年   1815篇
  2020年   1059篇
  2019年   1497篇
  2018年   1711篇
  2017年   1198篇
  2016年   1349篇
  2015年   1561篇
  2014年   2145篇
  2013年   2661篇
  2012年   3936篇
  2011年   3926篇
  2010年   1983篇
  2009年   1854篇
  2008年   3125篇
  2007年   3012篇
  2006年   2716篇
  2005年   2685篇
  2004年   2246篇
  2003年   2006篇
  2002年   1774篇
  2001年   239篇
  2000年   172篇
  1999年   245篇
  1998年   308篇
  1997年   225篇
  1996年   201篇
  1995年   184篇
  1994年   154篇
  1993年   124篇
  1992年   94篇
  1991年   81篇
  1990年   66篇
  1989年   48篇
  1988年   40篇
  1987年   40篇
  1986年   38篇
  1985年   36篇
  1984年   45篇
  1983年   30篇
  1982年   40篇
  1981年   27篇
  1980年   23篇
  1978年   16篇
  1977年   14篇
  1973年   13篇
  1972年   15篇
  1968年   13篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
Familial amyloidotic polyneuropathy (FAP) is an inherited disease characterized by an abnormal systemic deposition of a mutant protein called transthyretin (TTR) with elective involvement of the peripheral nervous system, but often determining cardiac, gastrointestinal, and urinary tract dysfunction. FAP commonly affects the liver and the heart until end-organs failure. Transthyretin amyloidosis is today an accepted indication for orthotopic liver transplantation (OLT). Combined heart and liver transplantation (CHLT) may be an attractive and rational treatment option when both organs are contemporary involved by this type of amyloidotic disease. Nowadays, surgical indications and techniques are far from being consolidated because only few cases of CHLT have been previously reported in literature. From November 1999 to May 2006, we performed five orthotopic combined heart and liver transplantations for FAP at our institution. Our surgical experience and clinical outcomes are herein reported.  相似文献   
102.
Re-resection for gallbladder carcinoma incidentally discovered after cholecystectomy is routinely advocated. However, the incidence of finding additional disease at the time of re-resection remains poorly defined. Between 1984 and 2006, 115 patients underwent re-resection at six major hepatobiliary centers for gallbladder carcinoma incidentally discovered during cholecystectomy. Data on clinicopathologic factors, operative details, TNM tumor stage, and outcome were collected and analyzed. Data on the incidence and location of residual/additional carcinoma discovered at the time of re-resection were also recorded. On pathologic analysis, T stage was T1 7.8%, T2 67.0%, and T3 25.2%. The median time from cholecystectomy to re-resection was 52 days. At the time of re-resection, hepatic surgery most often consisted of formal segmentectomy (64.9%). Patients underwent lymphadenectomy (LND) (50.5%) or LND + common bile duct resection (43.3%). The median number of lymph nodes harvested was 3 and did not differ between LND alone (n = 3) vs LND + common duct resection (n = 3) (P = 0.35). Pathology from the re-resection specimen noted residual/additional disease in 46.4% of patients. Of those patients staged as T1, T2, or T3, 0, 10.4, and 36.4%, respectively, had residual disease within the liver (P = 0.01). T stage was also associated with the risk of metastasis to locoregional lymph nodes (lymph node metastasis: T1 12.5%; T2 31.3%, T3 45.5%; P = 0.04). Cystic duct margin status predicted residual disease in the common bile duct (negative cystic duct, 4.3% vs positive cystic duct, 42.1%) (P = 0.01). Aggressive re-resection for incidental gallbladder carcinoma is warranted as the majority of patients have residual disease. Although common duct resection does not yield a greater lymph node count, it should be performed at the time of re-resection for patients with positive cystic duct margins because over one-third will have residual disease in the common bile duct. Presented at the 48th Annual Meeting of the Society for Surgery of the Alimentary Tract at Digestive Week 2007, Plenary Session, Washington, DC, March 23, 2007.  相似文献   
103.
Nowadays, microsurgery performed for oral reconstruction of cancer patients, has become the standard treatment in restoring oral functions. The free radial forearm flap (FRFF) is still apparently the first reconstructive choice in oral cavity cancers. Recently the anterolateral thigh flap (ALTF) seemed to challenge the superiority of FRFF. The lack of functional data on which to base this recent supposition is the reason for this new research. Twenty reconstructed patients were enrolled for this study. Speech, swallowing, and donor site complications were studied to assess differences between the two techniques. Results show that difference in function between ALTF and FRFF groups is statistically insignificant. Donor site risks and complications seem to be the only variables among groups. These variables may be used as indicators when making a surgical choice.  相似文献   
104.
In this work, the dosimetric characteristics of a new commercial carbon fiber treatment table are investigated. The photon beam attenuation properties of the Siemens image-guided radiation therapy (IGRT) tabletop were studied in detail. Two sets of dosimetric measurements were performed. In the first experiment a polystyrene slab phantom was used: the central axis attenuation and the skin-sparing detriment were investigated. In the second experiment, the off-axis treatment table transmission was investigated using a polystyrene cylindrical phantom. Measurements were taken at the isocenter for a 360° rotation of the radiation beam. Our results show that the photon beam attenuation of the Siemens IGRT carbon fiber tabletop varies from a minimum of 2.1% (central axis) to a maximum of 4.6% (120° and 240° beam incidence). The beam entrance dose increases from 82% to 97% of the dose at the depth of maximum for a clinical 6-MV radiation field. The depth of maximum also decreases by 0.4 cm. Despite the wedge cross section of the table the beam attenuation properties of the IGRT tabletop remain constant along the longitudinal direction. American Association of Medical Dosimetrists.  相似文献   
105.
The objective of this prospective, randomized, double-blind study was to determine if preoperative administration of a femoral nerve block reduces the amount of morphine needed for postoperative analgesia after total knee arthroplasty (TKA). Forty-two patients undergoing TKA were randomly assigned to receive either a femoral nerve block (0.50% bupivacaine hydrochloride with epinephrine 1:200,000) or matching placebo. Results showed postoperative morphine use was significantly lower in patients who received the nerve block (25.5 vs 37.5 mg, P = .016); however, the 2 groups had similar pain scores and rehabilitative outcomes. In general, a preoperative femoral nerve block is a safe and effective adjunct for decreasing morphine use for post-TKA analgesia.  相似文献   
106.
To date, few studies have examined the personality characteristics and clinical predictors of impulsive behaviors in eating disorders (ED). The aim of this work was to study the prevalence of a wide range of impulsive behaviors in a sample of 554 ED subjects and to examine the predictors of these behaviors. Subjects were diagnosed according to DSM-IV criteria as having anorexia nervosa restricting type (ANR; n = 183), anorexia nervosa binge eating/purging type (ANBP; n = 65), bulimia nervosa purging type (BNP; n = 244), and bulimia nervosa nonpurging type (BNNP; n = 62). Nine different types of impulsive behaviors were assessed in these groups. About 55% of the whole sample reported at least one type of impulsive behavior, 35% more than one, and about 13% more than three. According to findings, impulsive and multi-impulsive subjects are characterized by the presence of purging behavior and by specific temperamental features such as high levels of novelty seeking and low persistence. The prediction of impulsive behavior is further improved by considering the presence of a history of childhood abuse, maternal psychiatric morbidity, and some specific psychological symptoms such as maturity fears, perfectionism, depression, and obsessive-compulsive symptoms. The presence of impulsive behavior appears to be associated with overall higher levels of psychiatric symptomatology and eating psychopathology, thus indicating that they are an important feature to be considered in the assessment and treatment of ED.  相似文献   
107.
108.
Video-assisted minimally invasive cardiac surgery (VAMICS) is currently performed with various indications. However, despite the increasing evidence of its effectiveness, new approaches have to be defined to simplify this procedure, minimize its potential complications and limit its costs, for a wider use in the surgical community. The limited access to the aorta is a key point in VAMICS and mandates specific clamping modalities with their own limitations, costs and drawbacks. The Portaclamp (Cardio Life Research SA, Louvain la Neuve, Belgium), a new autoguided extravascular aortic cross-clamping system, has been recently proposed to facilitate VAMICS. Herein, we describe the Portaclamp approach and report our indications and preliminary clinical experience so to define its role in VAMICS.  相似文献   
109.
Over 800 Maine residents will be diagnosed with colorectal cancer (CRC) this year, and nearly 300 will die from the disease. While CRC screening can reduce these rates, it is only among insured populations that screening rates exceed 50%. This project aimed to reduce barriers to, and increase rates of CRC screening among underinsured and uninsured women, ages 50 years and over, residing in Cumberland County, Maine. The existing network of the Maine Breast and Cervical Health Program (MBCHP) was used to reach the target population. A packet containing (1) an offer for no-cost fecal occult blood test (FOBT) screening and CRC-related educational materials, and (2) a stamped, addressed postcard specifying the woman’s interest in these resources, was mailed to 300 MBCHP enrollees residing in Cumberland County. Women requesting screening were contacted by phone to further determine eligibility. Ninety-three women (31%) requested FOBT kits and 29 of these women requested educational materials. Ten women were ineligible for screening because of previous colonoscopy. Fifty-two completed FOBT kits (63%) were returned; all were negative. An additional 42 (14%) women requested educational materials only. To reduce the burden of CRC in Maine and nationally, disparate populations must be reached with efficient and effective screening services. Established networks are proven means for reaching uninsured and underinsured individuals with education, screening services, and necessary follow-up care. This project serves as a model for the future development of similar programs statewide and nationally.  相似文献   
110.
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