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   1934篇
  免费   74篇
  国内免费   10篇
耳鼻咽喉   19篇
儿科学   69篇
妇产科学   160篇
基础医学   240篇
口腔科学   50篇
临床医学   201篇
内科学   402篇
皮肤病学   25篇
神经病学   192篇
特种医学   51篇
外科学   364篇
综合类   4篇
预防医学   41篇
眼科学   38篇
药学   62篇
肿瘤学   100篇
  2024年   2篇
  2023年   7篇
  2022年   6篇
  2021年   18篇
  2020年   14篇
  2019年   15篇
  2018年   25篇
  2017年   16篇
  2016年   17篇
  2015年   32篇
  2014年   32篇
  2013年   65篇
  2012年   131篇
  2011年   115篇
  2010年   81篇
  2009年   85篇
  2008年   134篇
  2007年   156篇
  2006年   155篇
  2005年   172篇
  2004年   166篇
  2003年   129篇
  2002年   105篇
  2001年   15篇
  2000年   13篇
  1999年   20篇
  1998年   39篇
  1997年   19篇
  1996年   24篇
  1995年   28篇
  1994年   20篇
  1993年   19篇
  1992年   13篇
  1991年   12篇
  1990年   12篇
  1989年   11篇
  1988年   12篇
  1987年   6篇
  1986年   8篇
  1985年   12篇
  1984年   7篇
  1983年   6篇
  1982年   9篇
  1981年   9篇
  1980年   3篇
  1979年   6篇
  1978年   5篇
  1977年   3篇
  1975年   2篇
  1974年   2篇
排序方式: 共有2018条查询结果,搜索用时 15 毫秒
91.
Zusammenfassung Operationsziel Anatomische Reposition und minimalinvasive Stabilisierung pertrochantärer Frakturen mit der perkutanen Kompressionsplatte (PCCP). Sofortige postoperative Vollbelastung. Indikationen Pertrochantäre Frakturen. Kontraindikationen Pertrochantäre Frakturen, die nicht geschlossen reponiert werden können, subtrochantäre Frakturen und reverse oblique fractures (AO/OTA 31-A3). Operationstechnik Der Patient wird auf einem Extensionstisch gelagert. Das Femur distal der Fraktur wird durch eine dorsale Repositionshilfe (PORD [posterior reduction device]) unterstützt. Reposition der Fraktur durch geschlossene Manipulation. Perkutanes Einführen der Platte über eine proximale laterale Inzision. Die Platte wird mit Hilfe einer Zange über eine zweite, mehr distal gelegene Inzision an den proximalen Femurschaft angelegt. Einbringen der Gleitschrauben durch die Platte in den Schenkelhals und Sicherung der Platte am Femurschaft mit drei zusätzlichen Schrauben. Abschließend Vervollständigung der Frakturstabilisierung mit einer zweiten Schenkelhalsschraube. Ergebnisse Von 130 Patienten mit einer pertrochantären Fraktur, die zwischen Mai 2000 und Dezember 2001 mit der beschriebenen Technik in der Hadassah-Universitätsklinik für Orthopädische Chirurgie, Jerusalem, Israel, behandelt wurden, konnten 108 in diese Studie eingeschlossen werden. Das Patientenalter lag bei durchschnittlich 81 Jahren (± 8 Jahre). Die durchschnittliche Operationszeit betrug 67 min, der Krankenhausaufenthalt lag bei 11,5 Tagen. 40% der Patienten benötigten während des Krankenhausaufenthalts keine Bluttransfusion, wohingegen 8,3% mehr als drei Erythrozytenkonzentrate erhielten. Komplikationen traten bei vier Patienten auf: in zwei Fällen Implantatversagen, das erfolgreich mit Kompressionshüftschrauben (CHS) behandelt wurde, und eine Pseudarthrose, die mit einer Arthroplastie behandelt wurde. Der vierte Patient hatte eine Beinverkürzung von 3 cm, die mit einer Schuherhöhung ausglichen wurde. Drei Patienten entwickelten eine Infektion, wovon eine ein chirurgisches Débridement erforderte.(Übersetzt von R. Attal, Innsbruck)  相似文献   
92.
Pérez J  Ware MA  Chevalier S  Gougeon R  Shir Y 《Anesthesia and analgesia》2005,101(2):444-8, table of contents
Certain dietary proteins and oils are capable of decreasing chronic neuropathic pain levels in rats after partial sciatic nerve ligation injury. We tested, for the first time, the role of dietary polyunsaturated fatty acids in suppressing pain in partial sciatic nerve ligation-injured rats. Six groups of male Wistar rats were fed an identical casein-based, fat-free diet for 1 wk preceding partial sciatic nerve ligation injury and for 1 wk thereafter. In addition, rats received, via gavage, 1 mL/day of pure canola, corn, hemp, soy, or sunflower oil, differing significantly in their omega-3 and omega-6 polyunsaturated fatty acid content, or 1 mL of plain water. Responses to tactile and noxious heat stimuli were recorded before and after surgery and a difference score was calculated for each group by subtracting the preoperative from the post-partial sciatic nerve ligation values. Heat hyperalgesia, but not tactile allodynia, was significantly different among the dietary groups (P = 0.005). Heat hyperalgesia of rats fed hemp oil, developing the most robust response, was significantly larger compared with rats fed corn oil, developing the least pain model (difference score: 24.3 +/- 4.1 s versus 6.1 +/- 3.1 s, respectively; P < 0.001). These oils contain similar levels of omega-6 polyunsaturated fatty acids (hemp, 60%; corn, 58%) but their omega-3 levels are 28-fold different (20% versus 0.7%, respectively). A significant correlation was found among dietary levels of omega-3, but not omega-6 or the omega-3/omega-6 ratio, of the six dietary groups and heat hyperalgesia (P = 0.006). We conclude that dietary oil might predict levels of neuropathic pain in rats and that this effect may be associated with dietary omega-3 levels. IMPLICATIONS: We found that certain commonly used oils can have a significant analgesic effect in rats with persistent pain after partial nerve injury. This effect may be associated with the amounts of omega-3 fatty acids consumed by rats.  相似文献   
93.
OBJECTIVE: To examine the effects of pulsed short-wave diathermy (PSWD), delivered at an intensity sufficient to induce a thermal sensation and at an athermal intensity, in comparison with a placebo short-wave diathermy treatment, on reported pain, stiffness and functional ability and on mobility performance of patients with osteoarthritis of the knee. DESIGN: A placebo-controlled double-blind trial with sequential allocation of patients to different treatment groups. SETTING: Outpatient physiotherapy department. SUBJECTS: One hundred and three consecutive patients, mean age 73.7 (+/-6.6) years with osteoarthritis of one or both knees for at least three months. INTERVENTIONS: All participants received three 20-min-long treatments per week for three weeks. One group received PSWD with mean power of 18 W (thermal effect), one group received PSWD with mean power of 1.8 W (athermal effect), and one group received sham short-wave diathermy treatment. Patients were assessed before the initial treatment, immediately following the last treatment, and at a three-month follow-up. MAIN MEASURES: Outcome measures included the WOMAC Osteoarthritis Index, which assessed reported pain, stiffness, and functional ability, and four measures of mobility performance: Timed Get Up and Go test (TGUG), stair-climbing, stair, descending and a 3-min walk. RESULTS: A difference across time was observed for the pain and stiffness categories of the WOMAC Osteoarthritis Index (p = 0.033 and p = 0.008, respectively), with no differences between groups. No other significant differences across time or between groups were observed in any of the other measures. CONCLUSION: The findings do not demonstrate pulsed short-wave diathermy, as it is utilized in clinical settings, to be effective in the treatment of osteoarthritis of the knee.  相似文献   
94.
The use of copper intrauterine contraceptive devices is currently limited to 2–3 years, mainly due to wire fragmentation, which was observed as early as after 8 months of use. In the resulting search for a long-lasting device, two new systems of duplex wire, with gold and platinum cores electrolytically coated with copper, were devised and studied. Initially, duplex wires and controls were exposed to physiological solution. Copper dissolution rate, and corrosion morphology were studied by weight-loss measurements and optical metallography. Similar systems were then surgically implanted in rat uteri for varying periods up to 26 weeks. Electron microanalysis of corrosion products in addition to weight-loss measurements and metallography was performed.The results showed that a uniform and ductile copper coating is obtainable by electroplating on gold and platinum wires. The rate of copper dissolution is similar to that of solid copper wire. No dissolution of gold and platinum in the controls or coated wires was detected by weight loss, metallography or atomic absorption measurements.Microanalysis of the deposits and corrosion products on the wires in the uterine environment showed the presence of compounds containing sulphur, chlorine, calcium and copper.The results of this study suggest that supplementing IUDs with copper-coated gold or platinum wires may result in significant prolongation of the life-span of the device by preventing uncontrolled loss of copper caused by wire fragmentation.  相似文献   
95.
Domestic violence and substance abuse are common in primary care patients. Although these problems are associated with severe physical and psychological sequelae, they are often undiagnosed. This article provides an overview of the prevalence of these problems, the health-related consequences for adults, children and elderly, as well as the challenges for clinicians in screening, assessment and referral.  相似文献   
96.
OBJECTIVE: The purpose of this study was to evaluate the relationship between prepregnancy maternal body mass index and spontaneous preterm birth and indicated preterm birth. STUDY DESIGN: This was a secondary analysis of the Maternal-Fetal Medicine Units Network, Preterm Prediction study. Patients were classified into categories that were based on their body mass index. Rates of indicated and spontaneous preterm birth were compared. RESULTS: Five hundred ninety-seven (20.5%) of 2910 women were obese. Obese women had fewer spontaneous preterm births at < 37 weeks of gestation (6.2% vs 11.2%; P < .001) and at < 34 weeks of gestation (1.5% vs 3.5%; P = .012). Women with a body mass index of < 19 kg/m2 had 16.6% spontaneous preterm birth, with a body mass index of 19 to 24.9 kg/m 2 had 11.3% spontaneous preterm birth, with a body mass index of 25 to 29.9 kg/m2 had 8.1% spontaneous preterm birth, with a body mass index of 30 to 34.9 kg/m2 had 7.1% spontaneous preterm birth, and with a body mass index of > or = 35 kg/m2 had 5.2% spontaneous preterm birth (P < .0001). Indicated delivery was responsible for an increasing proportion of preterm births with increasing body mass index (P = .001). Obese women had lower rates of cervical length < 25 mm (5% vs 8%; P = .012). Multivariable regression analysis confirmed a lower rate of spontaneous preterm birth in obese gravid women (odds ratio, 0.57; 95% CI, 0.39-0.83; P = .003). CONCLUSION: Obesity before pregnancy is associated with a lower rate of spontaneous preterm birth.  相似文献   
97.
98.
99.
We tested the efficacy and safety of glutamine (0.6 gm/kg/day) and creatine (5 gm/day) in 50 ambulant boys with Duchenne muscular dystrophy in a 6-month, double-blind, placebo-controlled clinical trial. Drug efficacy was tested by measuring muscle strength manually (34 muscle groups) and quantitatively (10 muscle groups). Timed functional tests, functional parameters, and pulmonary function tests were secondary outcome measures. Although there was no statistically significant effect of either therapy based on manual and quantitative measurements of muscle strength, a disease-modifying effect of creatine in older Duchenne muscular dystrophy and creatine and glutamine in younger Duchenne muscular dystrophy cannot be excluded. Creatine and glutamine were well tolerated.  相似文献   
100.
Texture discrimination and bounding contour extraction are essential parts of the object segmentation and shape discrimination process. As such, successful texture and contour processing are key components underlying the development of the perception of both objects and surfaces. By recording visual-evoked potentials, we investigate whether young infants can detect orientation-defined textures and contours. We measured responses to an organized texture comprised of many Gabor patches of the same orientation, alternated with images containing the same number of patches, but all of random orientation. These responses were compared with a control condition consisting of the alternation between two independently random configurations. Significant difference potentials were found as early as 2-5 months, as were significant odd harmonics in the test conditions. Responses were also measured to Gabor patches organized either as circles (all patches tangent to an imaginary circular path) alternated with pinwheels (all patches having a fixed orientation offset from the path). Infants between 6 and 13 months also showed sensitivity to the global organization of the elements along contours. Differential responses to our texture and contour stimuli and their controls could only have been generated by mechanisms that are capable of comparing the relative orientation of 2 or more patches, as no local information at a single patch distinguished the random and organized textures or the circle and pinwheel configurations.  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