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   181篇
  免费   4篇
儿科学   2篇
妇产科学   1篇
基础医学   15篇
口腔科学   18篇
临床医学   26篇
内科学   73篇
皮肤病学   20篇
神经病学   2篇
外科学   10篇
一般理论   1篇
预防医学   7篇
眼科学   2篇
药学   8篇
  2017年   2篇
  2016年   2篇
  2015年   2篇
  2014年   3篇
  2013年   11篇
  2012年   4篇
  2011年   1篇
  2010年   8篇
  2009年   4篇
  2007年   1篇
  2006年   1篇
  2005年   1篇
  2002年   1篇
  2001年   4篇
  2000年   5篇
  1999年   9篇
  1998年   14篇
  1997年   7篇
  1996年   15篇
  1995年   7篇
  1994年   8篇
  1993年   8篇
  1992年   12篇
  1991年   2篇
  1990年   4篇
  1989年   7篇
  1988年   7篇
  1987年   3篇
  1986年   5篇
  1985年   3篇
  1984年   3篇
  1983年   3篇
  1982年   1篇
  1981年   1篇
  1979年   1篇
  1978年   1篇
  1977年   1篇
  1976年   2篇
  1974年   1篇
  1969年   1篇
  1965年   1篇
  1964年   2篇
  1963年   2篇
  1961年   1篇
  1954年   2篇
  1949年   1篇
排序方式: 共有185条查询结果,搜索用时 11 毫秒
41.
Purpose: For contemporary hydrophilic resin adhesive systems, bonding to dentin is improved if the substrate is maintained in a hydrated state following acid‐etching. The purpose of this study was to compare the dentin shear bond strengths of two single‐bottle adhesives (one acetone‐based and one ethanol‐based) applied under different etched‐dentin conditions: dry, wet, or dry and re‐wetted with different solutions. Materials and Methods: Bovine incisors (N = 120) were mounted in acrylic, polished to 600‐grit, and randomly assigned to 12 groups (n = 10). Dentin was etched for 15 seconds using 35% phosphoric acid, rinsed, and either blot‐dried, air‐dried, or air‐dried and re‐wetted with different solutions (distilled water, Gluma Desensitizer, Aqua‐Prep, and 5% glutaraldehyde in water). Two adhesives (Single Bond and Prime & Bond NT) were applied to each of the surface conditions following manufacturers' instructions. After adhesive application and curing, composite was applied in a No. 5 gelatin capsule and light‐cured. Specimens were loaded in shear, using an Instron at 5 mm per minute. Shear bond strengths were calculated by dividing the failure load by the bonded surface area. Data were subjected to analysis of variance (ANOVA) and a post hoc Tukey test. Results: Mean shear bond strengths ranged from 12.5 to 26.6 MPa for Single Bond and from 5.6 to 14.7 MPa for Prime & Bond NT. Significant differences were found in both groups of materials (p < .001). The three highest mean bond strengths were obtained (in order) on dentin that was re‐wetted with Gluma Desensitizer, re‐wetted with Aqua‐Prep, or never dried. Differences between these surface conditions were not statistically significant for either material. CLINICAL SIGNIFICANCE Different dentin surface conditions and re‐wetting techniques affected bond strengths for adhesives studied. Aqua‐Prep and Gluma Desensitizer can be successfully used as re‐wetting agents. The use of a re‐wetting agent may be beneficial when dentin is dried after acid‐etching and rinsing.  相似文献   
42.
Several non-randomized studies suggest a possible survival advantage for chronic myelogenous leukaemia (CML) patients treated with an autologous stem-cell transplantation. Due to the possible contribution of residual leukaemic cells present in the inoculum in post-transplant relapse, several methods are being evaluated to eliminate neoplastic cells or to select 'normal' (Ph1 negative) progenitor cells for autografting. Recently, several studies have shown that Ph1 negative blood progenitor cells can be mobilized by rHuG-CSF alone in patients who have a cytogenetic response to alpha-interferon (IFN). We describe the first case, as far as we are aware, of a CML patient responding to IFN autografted by using blood progenitor cells collected by rHuG-CSF alone.  相似文献   
43.
The cis (2a) and trans (2b) isomers of methyl 3-benzamido-2-piperidinone-6-carboxylate (Apca) were prepared and separated by fractional recrystallizations. Proton n.m.r. studies in dimethylsulfoxide solution indicate that the six-membered lactam ring adopts a distorted chair conformation with an equatorially oriented benzamido substituent in both 2a and 2b. The carboxyl function also is equatorially oriented in the trans isomer 2b, but is disposed axially in the cis isomer 2a. In the crystal structure, the six-membered lactam ring of 2a is clearly in a boat conformation with the benzamido and carboxyl functions attached to the two apex carbon atoms equatorially. The trans isomer, 2b, exists as two crystallographically independent, conformationally distinct molecules in one unit cell. The lactam ring in both molecules adopts a distorted chair conformation, as is the case in solution, with both the benazamido and carboxyl functions attached equatorially. The rotameric orientation for the endocyclic lactam differs between the two molecules. Both structures show evidence of C—H.O hydrogen bond formation intermolecularly in the solid state. This ability, along with the distinctive conformational features of Apca, may be exploitable in the design of unique features of polypeptides.  相似文献   
44.
45.
Use of long-term total parenteral nutrition (TPN) is often presumed to be associated with serious hepatic dysfunction. In this retrospective study, we reviewed the complete charts of patients who had received TPN for more than 2.5 years, starting in infancy or childhood, for evidence of liver dysfunction. There were 16 male and 10 female patients with a total of 254.5 patient years on TPN. Seventeen patients have been on TPN since birth or early infancy. Thirteen of 26 patients derive ≥90% of their calorie intake from TPN. Six patients had hepatomegaly; two of them also had splenomegaly. Twenty-one patients had normal transaminases, nine have had past episodes of raised enzymes ranging from 2.5 to 7.5 times normal. Seventeen patients always had normal bilirubin levels, five had past episodes of hyperbilirubinaemia, while four patients had persistently raised bilirubin levels (range 1.5–20.7 g/dL). Alkaline phosphatase was normal for age in all patients except two. Hepatic synthetic function, as measured by albumin, pre-albumin levels and prothrombin time, was within the normal range in all patients except one. Liver biopsies were performed in eight patients. Two biopsies showed cirrhosis, one showed chronic active hepatitis (CAH) with cholestasis, two patients had fibrosis, one showed cholestasis and two biopsies were normal. One patient with cirrhosis and one with CAH were positive for hepatitis C antibody. Another asymptomatic patient was positive for hepatitis B. Only the patient with CAH had hepatic decompensation. We conclude that clinical hepatic failure is uncommon in our group of patients on long-term TPN for 2.5 years or more. Cirrhosis and fibrosis, when found, could not be solely attributed to TPN.  相似文献   
46.
47.
Objectives: To characterize the early changes in right ventricular [right ventricle (RV)] geometry and function, as assessed by two-dimensional (2-D) and Doppler echocardiography, after balloon-dilation atrial septostomy (BDAS) in patients with severe primary pulmonary hypertension (PPH). Background. Survival in PPH is to a great extent dependent on the functional status of the RV. BDAS recently has been shown to improve functional class and hemodynamics in patients with PPH nonresponsive to conventional vasodilator treatment. Methods: Ten patients with severe PPH who underwent BDAS were studied with transthoracic and transesophageal 2-D and Doppler echocardiography. RV dimensions were measured in the apical four-chamber view. Continuous-wave Doppler echocardiography was used to obtain peak velocity of tricuspid regurgitation. Transesophageal echocardiography (TEE) primarily was used for the follow-up of the atrial septal defects (ASDs). Results: In the early post-BDAS studies, right atrial and ventricular dimensions significantly decreased in all patients (P < 0.05). Global right ventricular wall motion (RVWM) also improved. RV percent change in area after septostomy inversely correlated with the changes in RV systolic area (r =–0.75; P < 0.05) and also with the baseline (preprocedure) values of RV percent change in area (r =–0.77; P < 0.05). Neither RV wall thickness nor the degree of tricuspid regurgitation were modified significantly after the procedure. Conclusions: BDAS in the setting of severe PPH results in moderate and salutary changes in geometry and function of the RV as assessed by 2-D echocardiography. These changes mainly appear to be the result of the decompression effect of atrial septostomy.  相似文献   
48.
INTRODUCTION In this study, we examined Radiesse (calcium hydroxylapatite; CaHA), Juvederm 24 (hyaluronic acid; HA-1A), Juvederm 24HV (HA-1B), and Perlane (HA-2) for patient satisfaction, likelihood to return, immediate efficacy, and duration of correction.
OBJECTIVE This multicenter, blinded, randomized study compares patient satisfaction variables, efficacy, and durability of CaHA gel and HA for correction of nasolabial folds (NLFs) through 12 months after 4-month touch-up.
METHODOLOGY A total of 205 randomized patients received either CaHA gel or HA for NLF treatment at initial visit and 4-month touch-up. Patients returned at 4, 8, and 12 months after the second injection for evaluation. Surveys measured patient satisfaction; effectiveness measures included the Global Aesthetic Improvement Scale (GAIS).
RESULTS More CaHA gel patients were satisfied or extremely satisfied than each HA tested. At 8 months, significantly more CaHA gel–treated NLFs were improved on the GAIS than any HA. The volumes of CaHA gel and three HA materials injected through 4 months were 2.2, 2.9, 4.8, and 2.9 mL, respectively ( p <.005). No serious adverse events were observed.
CONCLUSIONS In this controlled study, CaHA gel ranked highest in patient satisfaction and likelihood to return. The material was more effective and longer lasting than each HA in maintaining NLF augmentation.  相似文献   
49.
50.
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