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   453篇
  免费   29篇
耳鼻咽喉   1篇
儿科学   18篇
妇产科学   15篇
基础医学   70篇
口腔科学   7篇
临床医学   18篇
内科学   98篇
皮肤病学   7篇
神经病学   18篇
特种医学   69篇
外科学   77篇
综合类   8篇
预防医学   12篇
药学   14篇
中国医学   2篇
肿瘤学   48篇
  2021年   3篇
  2020年   5篇
  2019年   9篇
  2018年   7篇
  2017年   6篇
  2016年   8篇
  2015年   7篇
  2014年   8篇
  2013年   22篇
  2012年   20篇
  2011年   25篇
  2010年   27篇
  2009年   23篇
  2008年   28篇
  2007年   19篇
  2006年   20篇
  2005年   11篇
  2004年   8篇
  2003年   8篇
  2002年   13篇
  2001年   10篇
  2000年   8篇
  1999年   5篇
  1998年   16篇
  1997年   14篇
  1996年   15篇
  1995年   10篇
  1994年   8篇
  1993年   9篇
  1992年   6篇
  1991年   5篇
  1990年   5篇
  1989年   3篇
  1988年   10篇
  1987年   8篇
  1986年   7篇
  1985年   10篇
  1984年   2篇
  1983年   5篇
  1982年   2篇
  1981年   5篇
  1980年   8篇
  1979年   3篇
  1978年   3篇
  1977年   11篇
  1976年   5篇
  1975年   2篇
  1972年   2篇
  1968年   3篇
  1967年   2篇
排序方式: 共有482条查询结果,搜索用时 62 毫秒
1.
2.
HOCK LEONG EE  MBBS  MRCP    CHEE LEOK GOH  MBBS  FRCP    KHOO    ES-Y. CHAN  PHD    POR ANG  MBBS  MRCP 《Dermatologic surgery》2006,32(1):34-40
BACKGROUND: Acquired bilateral nevus of Ota-like macules (Hori's nevus) is a common dyschromatosis among Asian women. Q-switched lasers have been used successfully as a treatment modality. OBJECTIVE: The purpose of this study was to compare the efficacy of using the Q-switched 532 nm neodymium:yttrium-aluminum-garnet (Nd:YAG) laser followed by the 1,064 nm laser versus the Q-switched 1,064 nm Nd:YAG laser alone in the treatment of Hori's nevus. METHODS: This is a prospective left-right comparative study. Ten women with bilateral Hori's nevus were recruited and treated with a combination of the Q-switched 532 and 1,064 nm Nd:YAG lasers on the right cheek and the Q-switched 1,064 nm Nd:YAG laser alone on the left cheek. Only one laser treatment session was performed. The degree of pigmentation was objectively recorded with a mexameter. Subjective assessment was made by both patients and two blinded, nontreating dermatologists. RESULTS: At 6 months, there was a statistically significant difference (p = .009) of 35.10 points using objective mexameter measurements between the two sides, favoring the side treated with a combination of 532 and 1,064 nm laser treatment. Subjective grading by the patients and blinded dermatologists also confirmed that combination therapy was more successful after one treatment. Although combination treatment had a higher incidence of mild postinflammatory changes, this disappeared within 2 months. CONCLUSIONS: Concurrent use of the Q-switched 532 nm Nd:YAG laser in combination with the 1,064 nm laser is more effective in pigment clearance than the Q-switched 1,064 nm Nd:YAG laser alone for Hori's nevi.  相似文献   
3.
Kim  EE; Pjura  G; Lowry  P; Verani  R; Sandler  C; Flechner  S; Kahan  B 《Radiology》1986,159(2):443-446
Serial radionuclide studies using both Tc-99m DTPA (perfusion) and I-131 hippuran (tubular function) were correlated with histologic findings in 25 patients with renal transplants. These cases included 15 cases of cyclosporin-A nephrotoxicity (CsA-NT) and ten cases of acute cellular rejection that were retrospectively selected on the basis of biopsy findings and favorable clinical response to therapy specific for each of these conditions. The serial radionuclide studies enabled the correct diagnosis in 12 of 15 cases of CsA-NT and eight of ten cases of acute rejection. Posttherapy radionuclide studies, furthermore, demonstrated improvement consistent with clinical response. In all cases, the radionuclide results were available at least 24 hours before biopsy findings. These results indicate that serial radionuclide studies evaluating interval changes in both perfusion and tubular function are of significant value in the diagnosis and follow-up of CsA-NT and acute cellular rejection in transplant recipients. This initial experience suggests a sensitivity of 80%.  相似文献   
4.
Leukemic cells from two patients with Philadelphia-negative chronic myeloid leukemia (CML) were investigated: I) Cytogenetics showed a normal 46.XY karyotype in both cases, 2) molecular studies revealed rearrangement of the M-BCR region and formation of BCR-ABL fusion mRNA with b2a2 (patient I) or b3a2 (patient 2) configuration, and 3) fluorescence in situ hybridization (FISH) demonstrated relocation of the 5′ BCR sequences from one chromosome 22 to one chromosome 9. The ABL probe hybridized to both chromosomes 9 at band q34, while two other probes which map centromeric and telomeric of BCR on 22q 11 hybridized solely with chromosome 22. For the first time, a BCR-ABL rearrangement is shown to take place on 9q34 instead of in the usual location on 22q 11. A rearrangement in the latter site is found in all Ph-positive CML and in almost all investigated CML with variant Ph or Ph-negative, BCR-positive cases. The few aberrant chromosomal localizations of BCR-ABL recombinant genes found previously were apparently the result of complex and successive changes. Furthermore in patient 2, both chromosomes 9 showed positive FISH signals with both ABL and BCR probes. Restriction fragment length polymorphism (RFLP) analysis indicated that mitotic recombination had occurred on the long arm of chromosome 9 and that the rearranged chromosome 9 was of paternal origin. The leukemic cells of this patient showed a duplication of the BCR-ABL gene, analogous to duplication of the Ph chromosome in classic CML. In addition they had lost the maternal alleles of the 9q34 chromosomal region. The lymphocytes of patient 2 carried the maternal chromosome 9 alleles and were Ph-negative as evidenced by RFLP and FISH analyses, respectively. © 1993 Wiley-Liss, Inc.  相似文献   
5.
6.
The assumed advantages of the so-called leg-lifting technique over the back-lifting technique are still the subject of much debate. The present study was aimed at studying the consequences of performing both lifting techniques on net lumbar moments and spinal shrinkage. Furthermore, the relation between age and spinal shrinkage was studied. Five subjects approximately 40 years old and six subjects 20 years old performed six 5-min bouts of repetitive lifting using each technique on a separate day. Net lumbar moments were calculated using a two-dimensional dynamic linked segment model. Spinal shrinkage was measured at T12 and at the head after each bout of lifting and every 5 min during 1 h preceding the lifting bouts. The peak moments were marginally but significantly higher in the leg-lift. No differences in mean moments and shrinkage between lifting techniques were found. The shrinkage after the back-lift was more pronounced in the older subjects and a similar tendency was found after the leg-lift. The creep rate, i.e. the rate at which the shrinkage approaches its equilibrium was higher in the older subjects. No clear relations of anthropometrical variables and net moments with shrinkage was found. The common advice of using a leg-lift rather than a back-lift was not supported by the present study. Both the mechanical load on the low back (net moments) and the resulting shrinkage show considerable interindividual variation, the causes of which need further elucidation.

The leg-lifting technique is still widely advocated, thought its merits from a biomechanical point of view have been questioned. In this study spinal shrinkage and lumbar moments calculated by means of a dynamic linked segment model are used to compare the leg-lift to the more commonly used back-lift.  相似文献   

7.
8.
Aneurysm of the abdominal aorta in an eighteen-month-old child   总被引:1,自引:0,他引:1  
We report the case of an infected aneurysm of the abdominal aorta in a 18 month-old child, discovered by routine palpation of the abdomen during hospitalization for pneumonia. Ultrasonography and arteriography showed a 6 cm aneurysm of the abdominal aorta beginning distal to the renal arteries which occluded the right common Iliac artery. The aneurysm was treated by interposing a 6 mm Gore-Tex graft between the infrarenal aorta and the aortic bifurcation. Pathologic examination of the aneurysmal wall demonstrated a leukocytic Infiltrate and the presence of encapsulated Gram positive organisms. Arterial aneurysms are exceedingly rare in children. Their etiology is varied: infection, connective tissue disease, trauma, inflammatory arterial disease or other rare diseases such as tuberous sclerosis, neurofibromatosis, or Beçhet’s disease.  相似文献   
9.
10.
The plasminogen system plays an important role in the proteolytic degradation of extracellular matrices during wound healing. In the present study we investigated the impact of the plasminogen system on cardiac wound healing and function after myocardial infarction. Myocardial infarction was induced in plasminogen-deficient mice (Plg-/-) and in wild-type controls (Plg+/+). Structural analysis 1, 2, and 5 weeks after infarction revealed that infarct healing was virtually abolished in Plg-/- mice, indicating that the plasminogen system is required for the repair process of the heart after infarction. In the absence of plasminogen, inflammatory cells did not migrate into the infarcted myocardium. Necrotic cardiomyocytes were not removed and the formation of granulation tissue and fibrous tissue did not occur. In these non-healing infarcted hearts, LV dilatation was not altered. In addition, gelatinolytic activity of MMP-2 and MMP-9 was depressed in the Plg-/- infarcted hearts, suggesting that the plasmin effect on infarct healing may be mediated by MMPs. Surprisingly, cardiac function was only attenuated to a rather small extent in the Plg-/- infarcted mice when compared to the wild-types. This study provides direct prove that plasmin-mediated proteolysis plays a central role in cardiac wound healing after myocardial infarction in mice.  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