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   8612篇
  免费   651篇
  国内免费   24篇
耳鼻咽喉   55篇
儿科学   272篇
妇产科学   239篇
基础医学   1443篇
口腔科学   197篇
临床医学   1020篇
内科学   1713篇
皮肤病学   182篇
神经病学   866篇
特种医学   426篇
外科学   1047篇
综合类   81篇
一般理论   3篇
预防医学   680篇
眼科学   87篇
药学   483篇
中国医学   9篇
肿瘤学   484篇
  2023年   44篇
  2022年   56篇
  2021年   124篇
  2020年   98篇
  2019年   164篇
  2018年   178篇
  2017年   147篇
  2016年   185篇
  2015年   171篇
  2014年   219篇
  2013年   357篇
  2012年   453篇
  2011年   421篇
  2010年   256篇
  2009年   241篇
  2008年   364篇
  2007年   422篇
  2006年   430篇
  2005年   390篇
  2004年   347篇
  2003年   350篇
  2002年   344篇
  2001年   285篇
  2000年   293篇
  1999年   284篇
  1998年   147篇
  1997年   100篇
  1996年   102篇
  1995年   80篇
  1994年   86篇
  1993年   69篇
  1992年   187篇
  1991年   155篇
  1990年   141篇
  1989年   167篇
  1988年   127篇
  1987年   131篇
  1986年   116篇
  1985年   111篇
  1984年   100篇
  1983年   75篇
  1982年   49篇
  1981年   45篇
  1979年   71篇
  1978年   36篇
  1977年   51篇
  1975年   34篇
  1974年   44篇
  1973年   37篇
  1971年   37篇
排序方式: 共有9287条查询结果,搜索用时 15 毫秒
71.
Blood supply of the tibialis anterior tendon   总被引:3,自引:1,他引:2  
Injection techniques and immunohistochemical methods (antibodies against laminin) were performed to uncover the vascular pattern of the human tibialis anterior tendon with regard to spontaneous rupture of this tendon. Proximally, the blood supply of the tibialis anterior tendon mainly arises from the anterior tibial artery. Distally, the tendon is supplied by branches of the medial tarsal artery. Blood vessels enter the peritenon via vinculae from the posterior side. From the peritenon, the blood vessels penetrate the tendon and anastomose with a longitudinally orientated intratendinous network. Compared with the surrounding peritenon, the number of vessels in the tendon substance is greatly reduced. The distribution of blood vessels within the anterior tibial tendon is not homogenous. The posterior part of the tendon has a complete vascular network that extends from the musculotendinous junction to the insertion at the bone. In the anterior half of the tendon, there is an avascular zone between 45 and 67 mm in length. The location of the avascular zone correlates well with the location of the most frequent site of spontaneous rupture of the tibialis anterior tendon reported in the literature. Hypovascularity has to be considered as an etiological cofactor for spontaneous rupture of the tibialis anterior tendon.  相似文献   
72.
PURPOSE: To evaluate possible changes in aetiology and frequency of bulbar eviscerations and enucleations. METHODS: A total of 1028 cases from three two-year periods: 1975-76, 1985-86 and 1995-96 collected by the Eye Pathology Institute were reviewed. RESULTS: A significant decrease (p<0.001) in number of enucleations was observed from 358 in 1975-76 to 214 in 1995-96, corresponding to an almost equivalent increase in number of eviscerations from 5 in 1975-76 to 83 in 1995-96. The total number of eye removals decreased significantly (p<0.01) over the last two periods from 368 in 1985-86 to 296 in 1995-96. This was primarily caused by a decrease in the number of glaucoma-related enucleations from 32.7% in 1975-76 to 15.0% in 1995-96. The reduction in number was not fully balanced by the increase in glaucoma-related eviscerations. CONCLUSION: Over the last 20 years there has been a change in choice of operation from enucleation to evisceration.  相似文献   
73.
Brigham and Women's Hospital initiated a study of the quality of care centering on self-reporting of potential medical injuries by providers. The goal of the study is to decrease the incidence of such injuries through a continuous quality methodology that integrates providers into the identification phase and incorporates all hospital employees in the development of new practices. This article provides an overview of the investigation methodology and discusses the conceptual relationships between clinical epidemiological analyses and industrial quality improvement.  相似文献   
74.
Steady-state kinetics of imipramine in patients   总被引:1,自引:0,他引:1  
Steady-state plasma level kinetics were studied in 76 patients given imipramine (IP) 150 to 225 mg/day for 2–5 weeks. IP was given in three divided doses at 8.00 a.m., 1.00 p.m. and 5.00 p.m. Plasma concentrations of IP and its active metabolite desipramine (DMI) were determined by quantitative in situ thin-layer chromatography. The plasma levels of IP and DMI showed pronounced flucutations throughout the day with a ratio of about 2 between highest and lowest level. Patients with steady-state levels of IP and/or DMI below 50 g/l reached this within 1 week of treatment. Patients with higher steady-state levels reached steady-state concentrations within 2–3 weeks. There were some intraindividual fluctuations in plasma levels from week to week after steady state had been reached (coefficient of variation: 10–20%). Interindividually, the steady-state levels corrected to a dose of 3.5 mg/kg per day varied considerably: IP: 6–356 g/l, DMI: 24–659 g/l and IP+DMI: 58–809 g/l. The steady-state plasma levels showed a skew distribution that became normal by logarithmic transformation. The IP/DMI ratio ranged from 0.07 to 5.5 with a median value of 0.47. Compared to data from amitriptyline treated patients the IP/DMI ratios had significantly lower median value and larger variation than the corresponding plasma level ratios of amitriptyline/nortriptyline. Several statistically significant differences in steady-state levels between age groups were found. For IP: Women aged 30–39 had lower levels than women aged 20–29, 40–49, and 50–59, and men aged 50–59 and 60–65; men aged 30–39 had lower levels than men aged 60–65. For DMI: Women aged 30–39 had lower levels than women aged 50–59.  相似文献   
75.
76.
77.
78.
Abstract: We report the first case of fatal anthrax meningoencephalitis in Hong Kong over the past 60 years. A 13 year-old boy presented with right lower quadrant pain, diarrhoea and progressive headache. Lumbar puncture yielded gram positive bacilli initially thought to be Bacillus cereus, a contaminant. He was treated with ampicillin and cefotaxime, but died 3 days after hospitalization. The organism isolated from blood and cerebrospinal fluid was later identified as Bacillus anthracis.  相似文献   
79.
OBJECTIVE: Because the survival rate has increased for extremely low birth weight neonates, many have raised the concern that the rate of developmental disability among survivors will also increase. To address this concern, we analyzed changes over time in survival and major neurosensory impairment in a sample of extremely low birth weight infants born between July 1, 1979, and June 30, 1994. METHODS: The study sample included 513 infants with birth weights of 501 to 800 g who were cared for in either of the two neonatal intensive care units that serve a 17-county region in northwest North Carolina and who were born to mothers residing in that region. At 1 year of age (corrected for gestation), survivors were examined by a pediatrician and were tested using the Bayley Scales of Infant Development. Major neurosensory impairment was defined as cerebral palsy, a Bayley Mental Developmental Index <68, or blindness. A total of 209/216 (97%) of survivors were examined at 1 year of age. Epoch of birth was defined as follows: epoch 1, July 1, 1979 to June 30, 1984; epoch 2, July 1, 1984 to June 30, 1989; and epoch 3, July 1, 1989 to June 30, 1994. RESULTS: Survival rates for epochs 1, 2, and 3 were, respectively, 24/120 (20%), 63/175 (36%), and 129/218 (59%). In contrast, the proportions with a major neurosensory impairment did not increase over time; rates for successive epochs were 6/24 (25%), 17/61 (28%), and 26/124 (21%). Rates of cerebral palsy were 3/24 (13%), 12/61 (20%), and 9/124 (7%); rates of delayed mental development were 4/24 (17%), 12/61 (20%), and 17/124 (14%); and rates of blindness were 2/24 (8%), 0/62, and 5/124 (4%), respectively. CONCLUSIONS: This analysis suggests that the increasing survival of extremely low birth weight neonates since the late 1970s has not resulted in an increased rate of major developmental problems identifiable at 1 year of age.  相似文献   
80.
Zum Thema   Oftmals fatal verlaufende Infektionen in der Gravidit?t – vor allem postpartal – spielen immer noch trotz verbesserter Kenntnis zur Bakteriologie und Therapie, zur Infektionsprophylaxe und Hygiene eine gro?e Rolle. Als Folge der ver?nderten Immunlage in der Schwangerschaft kommt es h?ufig zu atypischen Verl?ufen, wodurch die Diagnostik erschwert wird. Auch zun?chst harmlos erscheinende Virusinfektionen k?nnen exazerbieren. Die einzelnen Krankheitsbilder (Sepsis, Amnioninfektionssyndrom, septischer Abort, Peritonitis und extragenitale Infektionen) sowie deren Diagnostik und Erreger werden besprochen. Besonders auf die antibiotische Kombinationstherapie wird eingegangen. Zusammenfassung   Schwangere mit Grundkrankheiten, Vorsch?den und Neigung zu rezidivierenden Genitalinfektionen sind in bezug auf lebensbedrohliche Infektionen vermehrt gef?hrdet. In Einzelf?llen bei hochpathogenen Erregern wie den Streptokokken der Gruppe A kann es nach Blasensprung oder operativen Eingriffen zu einer febrilen oder auch afebrilen t?dlichen Sepsis kommen. Die Beachtung der Vaginalflora, die Erkennung von Risikofaktoren und die frühzeitige und wirksame Antibiotikagabe verhindern sogenannte schicksalhafte Verl?ufe.  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