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   100篇
  免费   3篇
  国内免费   3篇
儿科学   12篇
妇产科学   1篇
基础医学   2篇
口腔科学   2篇
临床医学   5篇
内科学   30篇
神经病学   1篇
特种医学   10篇
外科学   10篇
综合类   6篇
预防医学   2篇
眼科学   2篇
药学   15篇
中国医学   6篇
肿瘤学   2篇
  2021年   1篇
  2017年   1篇
  2015年   4篇
  2014年   2篇
  2013年   4篇
  2011年   1篇
  2010年   5篇
  2009年   8篇
  2008年   4篇
  2007年   3篇
  2006年   6篇
  2005年   1篇
  2004年   4篇
  2003年   2篇
  2001年   1篇
  2000年   6篇
  1999年   4篇
  1998年   2篇
  1997年   3篇
  1996年   10篇
  1994年   3篇
  1993年   1篇
  1991年   2篇
  1990年   2篇
  1989年   2篇
  1988年   3篇
  1987年   4篇
  1986年   3篇
  1985年   4篇
  1982年   5篇
  1980年   1篇
  1978年   2篇
  1976年   1篇
  1969年   1篇
排序方式: 共有106条查询结果,搜索用时 31 毫秒
71.
AIM: To evaluate the techniques, results, and complications related to computed tomography(CT)-guided percutaneous core needle biopsies of solid pancreatic lesions.METHODS: CT-guided percutaneous biopsies of solid pancreatic lesions performed at a cancer reference center between January 2012 and September 2013 were retrospectively analyzed. Biopsy material was collected with a 16-20 G Tru-Core needle(10-15 cm; Angiotech, Vancouver, CA) using a coaxial system and automatic biopsy gun. When direct access to the lesion was not possible, indirect(transgastric or transhepatic) access or hydrodissection and/or pneumodissection maneuvers were used. Characteristics of the patients, lesions, procedures, and histologic results were recorded using a standardized form. RESULTS: A total of 103 procedures included in the study were performed on patients with a mean age of 64.8 year(range: 39-94 year). The mean size of the pancreatic lesions was 45.5 mm(range: 15-195 mm). Most(75/103, 72.8%) procedures were performed via direct access, though hydrodissection and/or pneumodissection were used in 22.2%(23/103) of cases and indirect transhepatic or transgastric access was used in 4.8%(5/103) of cases. Histologic analysis was performed on all biopsies, and diagnoses were conclusive in 98.1%(101/103) of cases, confirming3.9%(4/103) of tumors were benign and 94.2%(97/103) were malignant; results were atypical in 1.9%(2/103) of cases, requiring a repeat biopsy to diagnose a neuroendocrine tumor, and surgical resection to confirm a primary adenocarcinoma. Only mild/moderate complications were observed in 9/103 patients(8.7%),and they were more commonly associated with biopsies of lesions located in the head/uncinate process(n =8), than of those located in the body/tail(n = 1) of the pancreas, but this difference was not significant.CONCLUSION: CT-guided biopsy of a pancreatic lesion is a safe procedure with a high success rate, and is an excellent option for minimally invasive diagnosis.  相似文献   
72.
Bone marrow origin of a B-cell lymphoma   总被引:3,自引:0,他引:3  
To search for precursors of the neoplastic B cells in a patient with a nodular lymphoma, we produced a monoclonal antibody to a variable region idiotope on the lymphoma IgM heavy chain. Clonal ancestors of the lymphoma cells were identified by this marker among bone marrow pre- B cells (5% to 26%). A second antiidiotype (anti-Id) antibody specific for the complete lymphoma IgM kappa recognized 10% of B cells in bone marrow and blood and greater than 95% of B cells in lymphomatous lymph nodes, including one obtained after tumor conversion to a diffuse large cell lymphoma. Immunoglobulin gene analysis surprisingly revealed expansion of multiple clones of early B lineage cells in bone marrow, including members of the neoplastic clone. The data suggest that this lymphoma arose through a progression of transformational events beginning in bone marrow: first, creation of an oligoclonal pre- neoplastic pool of pre-B cells, subsequent conversion of a single subclone into low grade neoplastic B cells that homed to the lymph node follicles, and later progression to a more invasive form of the B-cell lymphoma.  相似文献   
73.

Introduction

Selective conservatism for thoracic trauma is well established but the emergence of new technologies may cause management strategies to continue to evolve.

Methods

A retrospective study was conducted on thoracic trauma patients managed in a single institution in South Africa over a 4-year period to determine the appropriateness of our current policy of selective conservatism.

Results

A total of 1,239 patients were included in the study; 112 required an emergency thoracotomy, 125 were admitted for observation and 1,002 required a tube thoracostomy (TT). Ninety-one per cent of the patients were male and the median age was 24 years. Seventy-five per cent of the cases were penetrating trauma and the remaining were blunt trauma. The indications for TT were pneumothorax (PTX) (n=382, 38%), haemothorax (HTX) (n=300, 30%) and haemopneumothorax (HPTX) (n=320, 32%).A total of 13% (127/1,002) of all chest x-rays (CXR) following tube removal demonstrated residual pathologies that precluded immediate discharge: 32 (8%) in Group A (PTX), 44 (15%) in Group B (HTX) and 51 (16%) in Group C (HPTX). All 32 patients in Group A were simply observed and did not require further intervention. In Group B, 17 patients required repeat TTs and 27 required video assisted thoracoscopic surgery (VATS) for clearance of residual HTX. Twenty-nine patients in Group C required repeat TTs and twenty-two required VATS.

Conclusions

The vast majority of patients with thoracic trauma can be managed conservatively with TT alone. Residual pathology appeared to be lowest in patients with a PTX, which seldom requires treatment, while only a minority of patients required repeat TTs or VATS for a retained HTX. Selective conservatism is still appropriate in the current era in a developing world setting.  相似文献   
74.
Objective:  To examine the effects of partial, single and multiple courses of antenatal corticosteroids (ANS) on the need for blood pressure support in extremely premature infants.
Methods:  Extremely premature infants with gestational age of 24 to 28 weeks were included in this study during a 5-year period. The main outcome measure of the study was the amount of blood pressure support during the first 3 days of life.
Results:  The study infants (n = 163) were divided into: infants not exposed (ANS; n = 27) and exposed to ANS (ANS; n = 136). Blood pressure support was significantly lower in ANS compared with No ANS (65% vs 96%; p = 0.003) and in single course (SANS; n = 73) and ≥2 courses (MANS; n = 34) compared with partial course of ANS (PANS; n = 29) (62%, 56% vs 86%; p = 0.03). The number of infants who received volume support and the amount of volume support were significantly lower in ANS compared with that in No ANS (p < 0.001) and in SANS and MANS compared with that in PANS (p < 0.02).
Conclusion:  Exposure to multiple courses of ANS was as beneficial as single course of ANS in decreasing the need for blood pressure support in extremely premature infants.  相似文献   
75.
76.
77.
AIM:To evaluate inflammatory activity in patients with Crohn‘s disease (CD) using technetium-99m-hexamethylpropyleneamine oxime (99mTc-HMPAO) granulocyte scintigraphy.METHODS: Twenty patients (7 male and 13 female) with CD and five healthy volunteers were selected for 99mTc-HMPAO granulocyte scintigraphy. The Crohn‘s Disease Activity Index (CDAI), blood tests and C-reactive protein (CRP) of each patient were performed 7 d before the scintigraphic images. The leukocytes were labeled according to the Internat...  相似文献   
78.
Curcumin, a component of turmeric (Curcuma longa), exhibits anti-inflammatory and anti-proliferative activities through the generation of reactive oxygen species (ROS). Curcumin (diferuloylmethane) contains two hydroxyl, two methoxy and two phenyl groups but how these groups contribute to its activity is poorly understood. We synthesized analogues that varied in inclusion of these groups and compared their activity. We found that bisdemethylcurcumin (BDC) was more potent than curcumin as an anti-inflammatory agent as indicated by suppression of TNF-induced NF-κB activation, more potent as an anti-proliferative agent, and more potent in inducing ROS. Hispolon, which lacks one aromatic unit in relation to curcumin, also exhibited enhanced anti-inflammatory and anti-proliferative activities. When synthetic curcumin (Cur-S) was compared with bisdemethylcurcumin (BDC), hispolon, hispolon methyl ether (HME), dehydroxy hispolon (DH), hydroxy hispolon (HH), methoxy hispolon methyl ether (MHME), and methoxy hispolon (MH), we found that following order of anti-inflammatory activity: BDC = Hispolon > HME > HH > Cur-S > MHME > MH > DH; for anti-proliferative: Hispolon > BDC > MHME > Cur-S > MH > HME = HH > DH; and for prooxidant: BDC > Cur-S = MHME > HH > MH + HME > DH (254-1414 mean fluorescence intensity). Thus, dehydroxy hispolon was least potent for all three activities. Overall the results indicate that the substitution of a hydroxyl group for a methoxy group at the meta positions of the phenyl rings in curcumin significantly enhanced the anti-inflammatory activity, and the removal of phenyl ring at the 7th position of the heptadiene back bone and addition of hydroxyl group significantly increased the anti-proliferative activity of curcumin.  相似文献   
79.
It has been suggested that the beneficial effects of reperfusing the myocardium might be in part reversed by the occurrence of reperfusion injury. Oxidative stress was suggested to be implicating in the pathogenesis of ischemia-reperfusion (I/R) injury. Many antioxidative plants were shown to be cardioprotective in experimental models of myocardial ischemia-reperfusion (I/R) injury. The present study was designed to investigate the effects of pretreatment with alcoholic extract of Tinospora cordifolia in an in vivo rat model. The model adopted was that of surgically-induced myocardial ischemia, performed by means of left anterior descending coronary artery occlusion (LAD) for 30 min followed by reperfusion for another 4 h. Infarct size was measured by using the staining agent TTC (2,3,5-triphenyl tetrazolium chloride). Lipid peroxide levels in serum and in heart tissue were estimated spectrophotometrically by the methods developed by Yagi and Ohkawa et al. respectively. A lead II electrocardiogram was monitored at various intervals throughout the experiment. A dose dependent reduction in infarct size and in lipid peroxide levels of serum and heart tissue were observed with the prior treatment of T. cordifolia with various doses for 7 d compared to control animals. Hence, the present study suggests the cardioprotective activity of T. cordifolia in limiting ischemia-reperfusion induced myocardial infarction.  相似文献   
80.
New acylated iridoid glucosides from Vitex altissima   总被引:1,自引:0,他引:1  
Six new iridoid glucosides, 6'-O-trans-feruloylnegundoside (1), 6'-O-trans-caffeoylnegundoside (2), 2'-O-p-hydroxybenzoyl-6'-O-trans-caffeoylgardoside (3), 2'-O-p-hydroxybenzoyl-6'-O-trans-caffeoyl-8-epiloganic acid (4), 2'-O-p-hydroxybenzoyl gardoside (5), and 2'-O-p-hydroxybenzoyl-8-epiloganic acid (6), along with two known iridoids, agnuside and negundoside, have been isolated from the ethyl acetate extractive of the leaves of Vitex altissima. The structures of these compounds were elucidated on the basis of spectral data interpretation. These isolates did not exhibit significant 5-lipoxygenase enzyme inhibitory activity, but compounds 2-4 showed potent antioxidant activity by both the superoxide (NBT riboflavin photoreduction) free-radical-scavenging and DPPH-radical-scavenging methods. Compounds 1, 2, and negundoside were evaluated in a rat paw edema assay.  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