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   1265篇
  免费   84篇
  国内免费   8篇
耳鼻咽喉   17篇
儿科学   61篇
妇产科学   25篇
基础医学   135篇
口腔科学   26篇
临床医学   111篇
内科学   201篇
皮肤病学   20篇
神经病学   127篇
特种医学   131篇
外科学   247篇
综合类   16篇
一般理论   1篇
预防医学   93篇
眼科学   17篇
药学   62篇
肿瘤学   67篇
  2023年   8篇
  2022年   7篇
  2021年   14篇
  2020年   9篇
  2019年   20篇
  2018年   28篇
  2017年   25篇
  2016年   28篇
  2015年   24篇
  2014年   37篇
  2013年   52篇
  2012年   92篇
  2011年   80篇
  2010年   74篇
  2009年   62篇
  2008年   62篇
  2007年   64篇
  2006年   58篇
  2005年   58篇
  2004年   41篇
  2003年   40篇
  2002年   29篇
  2001年   29篇
  2000年   29篇
  1999年   31篇
  1998年   29篇
  1997年   22篇
  1996年   25篇
  1995年   23篇
  1994年   13篇
  1993年   11篇
  1992年   19篇
  1991年   15篇
  1990年   20篇
  1989年   21篇
  1988年   20篇
  1987年   22篇
  1986年   17篇
  1985年   7篇
  1984年   7篇
  1982年   4篇
  1981年   5篇
  1980年   5篇
  1979年   5篇
  1977年   10篇
  1976年   6篇
  1972年   8篇
  1970年   4篇
  1968年   4篇
  1965年   6篇
排序方式: 共有1357条查询结果,搜索用时 15 毫秒
1.
2.
In trauma surgery there is a particularly high proportion of patients in the age group most at risk of infection with AIDS. The result of an epidemiological study in our patients (HIV screening of all patients scheduled for surgery at a trauma center over 18 months) showed a prevalence of 0.1%. Specific therapeutic strategies must be developed to deal with the weakened immunity of HIV-infected patients. Fracture treatment in HIV-infected hemophiliacs is a special problem. Homogenous bone transplantation is described with reference to HIV. The particular danger of injury in trauma surgery is also investigated. The chain of infection is illustrated and used to demonstrate the precautions that can be taken against nosocomial HIV infections. Following infection with fluids containing HIV, specific measures must be taken. The legal aspects of HIV-antibody testing in the Federal Republic of Germany are elucidated. Finally, the problems of general preoperative HIV-antibody testing are discussed.  相似文献   
3.
Summary 84 forensic necropsy cases with a history of sudden unexpected death and where no acceptable cause of death was found at autopsy (= cases of sudden unexplained death, SUD) were found to have a significantly higher rate of influenza A (H 3 N 2) infection than did matched controls of the general population and a group of forensic necropsy cases with known cause of death (NON-SUD cases).By contrast, the group of SUD cases was found to have no significantly increased infection rate with influenza H 1 N 1 and B virus, parainfluenza viruses, RS virus, adenovirus, and cytomegalovirus.The influenza A associated SUD cases had a significantly higher rate of pathological and histological findings previously described for cases of primary viral pneumonia than did SUD cases without recent influenza A infection and NON-SUD cases.These findings suggest that virological examination of SUD cases could be helpful in order to determine the probable cause of death.A considerable portion of the influenza associated SUD cases occurred during interepidemic influenza periods. Therefore, such cases could be a useful source for monitoring the interepidemic spread of influenza virus.  相似文献   
4.
A kindred is described with progressive autosomal dominant vestibulo-cochlear dysfunction resulting in instability in the dark, head movement dependent oscillopsia and hearing loss. The first symptoms appeared in the 4th decade and progressed to vestibular areflexia, presumably in the 5th decade and to almost total deafness in the 6th-7th decade of life. The history was negative for other neurological, otological or infectious diseases, or the use of neuro-ototoxic drugs. The affected subjects showed remarkable compensation for the loss of vestibular function.  相似文献   
5.
The correlation between velocity step (VS) and caloric response parameters was studied in a series of several hundred patients who underwent a neuro-otological examination. The VS parameters initial velocity (V in degree/s), time constant (T in s) and Gesamtamplitude G ( = VT in deg) were all significantly correlated with the caloric response parameters. The highest correlation coefficients were associated with G.  相似文献   
6.
BACKGROUND: Reconstruction of the infrarenal aorta for aneurysms is routinely performed through laparotomy. A less invasive videoscopic approach has not gained wide acceptance due to technical difficulties. Robotic systems could potentially improve imaging of the operative field and surgeon's dexterity during videoscopic surgery and therefore might facilitate the performance of this procedure. The aim of this animal study was to compare the safety and efficacy of a robot-assisted videoscopic aortic replacement to the standard videoscopic approach. MATERIALS AND METHODS: In 10 female pigs, the infrarenal aorta was partially replaced by a 10 mm polytetrafluoroethylene (PTFE) interposition graft through a videoscopic retroperitoneal approach, using the da Vinci robot system (robot group). Ten other pigs were operated on in a similar fashion, using standard videoscopic instruments (control group). Relevant procedure times, blood loss and complications were registered. Efficacy of the anastomoses was evaluated by measuring patency and blood loss after removing the clamps. Furthermore, circumference and number of stitches were evaluated at autopsy. RESULTS: The procedure, suturing and clamping times were significantly shorter in the robot group and blood loss was less. In the control group, the inferior vena cava was injured in one pig. In two cases in the control group, haemostasis could not be established after clamp removal. At autopsy, all anastomoses in the robot group were adequate. In the control group, a stitch crossing the aortic lumen was found in two distal anastomoses and a large distance (>3 mm) between two stitches was encountered at least once in 12/20 suture lines. All 20 grafts were patent. No anastomotic narrowing was encountered. The number of stitches used for proximal and distal anastomosis was higher in the robot group. CONCLUSION: This study demonstrates the superiority of robot-assisted videoscopic aortic replacement over standard videoscopic techniques in an animal model.  相似文献   
7.
The authors describe their experience with methyl tertiary butyl ether (MTBE) in a larger series of patients than previously reported in order to acquaint physicians with both its effectiveness for dissolution of common bile duct calculi and the limitations of its use. Ten patients with 13 biliary calculi underwent percutaneous stone dissolution treatment with the experimental cholesterol solvent, MTBE. Three stones completely dissolved within 30 minutes, seven were reduced in size, and three were visibly unaffected. All stones not completely dissolved were easily extracted by means of a stone basket except for one in a patient taken to surgery. Although MTBE perfusion is an effective technique for management of biliary calculi, practitioners should be aware that its use is quite time consuming and its odor difficult to control.  相似文献   
8.
In 13 patients with myotonic dystrophy, oculomotor, auditory, and vestibular tests were performed. All 13 patients showed one or more abnormalities. There was a significant increase in the penetrance of the separate abnormalities with age. Saccadic slowing was found in 10 patients, in a severe form in three. Seven patients had a sensorineural high-tone hearing loss (30 to 85 dB at 8 kHz), which was in excess of that expected for their age, that could be attributed to myotonic dystrophy. Brain-stem auditory evoked potentials showed a significant interwave delay of the I-V interval (0.35 to 0.7 milliseconds). An abnormal vestibulo-ocular reflex was found in six patients; three had vestibular hyperreflexia with increased gain, and three had hyporeflexia with short time constants. This study confirms that in myotonic dystrophy, sensory system involvement can be found on both a peripheral and a central level.  相似文献   
9.
Crosslineage T-cell receptor delta (TCR delta) rearrangements are widely used as tumor markers for the follow up of minimal residual disease in childhood B-precursor acute lymphoblastic leukemia (ALL) by polymerase chain reaction (PCR). The major drawback of this approach is the risk of false-negative results due to clonal evolution. We investigated the stability of V delta 2D delta 3 rearrangements in a group of 56 childhood B-precursor ALL patients by PCR and Southern blot analysis. At the PCR level, V delta 2D delta 3-to-J alpha rearranged subclones (one pathway for secondary TCR delta recombination) were demonstrated in 85.2% of V delta 2D delta 3-positive patients tested, which showed that small subclones are present in the large majority of patients despite apparently monoclonal TCR delta Southern blot patterns. Sequence analysis of V delta 2D delta 3J alpha rearrangements showed a biased J alpha gene usage, with HAPO5 and J alpha F in 26 of 32 and 6 of 32 clones, respectively. Comparison of V delta 2D delta 3 rearrangement status between diagnosis and first relapse showed differences in seven of eight patients studied. In contrast, from first relapse onward, no clonal changes were observed in six patients studied. To investigate the occurrence of crosslineage TCR delta rearrangements in normal B and T cells, fluorescence-activated cell sorter-sorted peripheral blood CD19+/CD3- and CD19-/CD3+ cell populations from three healthy donors were analyzed. V delta 2D delta 3 rearrangements were detected at low frequencies in both B and T cells, which suggests that V delta 2-to-D delta 3 joining also occurs during normal B-cell differentiation. A model for crosslineage TCR delta rearrangements in B-precursor ALL is deduced that explains the observed clonal changes between diagnosis and relapse and is compatible with multistep leukemogenesis of B-precursor ALL.  相似文献   
10.
A 38-year-old layer of parquet flooring was referred because of memory impairment, tiredness and diffuse headaches. His work involved using several neurotoxic organic solvents. Extensive laboratory, neuropsychological, clinical neurophysiological, neuroadiological, magnetic resonance (MR) imaging and spectroscopy studies were performed. The neuropsychological and behavioural assessments showed an organic brain syndrome. MR imaging and CT scanning of the brain revealed enlarged ventricles and generalized atrophy. 31P and 1H MR spectroscopic measurements did not show any abnormalities. Owing to recent improvements regarding sensitivity and facilitated assignment, MR spectroscopy may provide in the near future significant additional information on brain metabolism in patients with brain dysfunction presumably induced by organic solvents.  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