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   187篇
  免费   11篇
耳鼻咽喉   3篇
儿科学   2篇
妇产科学   2篇
基础医学   16篇
口腔科学   4篇
临床医学   27篇
内科学   39篇
皮肤病学   2篇
神经病学   5篇
特种医学   2篇
外科学   41篇
综合类   4篇
预防医学   12篇
眼科学   5篇
药学   13篇
肿瘤学   21篇
  2023年   6篇
  2022年   16篇
  2021年   12篇
  2020年   2篇
  2019年   3篇
  2018年   10篇
  2017年   5篇
  2016年   2篇
  2015年   6篇
  2014年   10篇
  2013年   11篇
  2012年   10篇
  2011年   24篇
  2010年   9篇
  2009年   4篇
  2008年   10篇
  2007年   3篇
  2006年   9篇
  2005年   10篇
  2004年   2篇
  2003年   6篇
  2002年   7篇
  2000年   4篇
  1999年   7篇
  1998年   2篇
  1993年   2篇
  1992年   4篇
  1985年   1篇
  1979年   1篇
排序方式: 共有198条查询结果,搜索用时 15 毫秒
91.
92.
Rationale, aims and objectives Cardiovascular diseases (CVD) are increasing at an alarming rate in South Asia. High blood pressure is a modifiable risk factor for CVD. In this study, we evaluated the control of blood pressure and the prevalence of cardiovascular risk factors in patients with hypertension. Method A cross‐sectional study was conducted in 50 primary health care centres throughout Pakistan. Individuals with a documented history of hypertension, receiving pharmacological therapy, were enrolled and evaluated for the control of their blood pressure. Results The recommended therapeutic control of hypertension (systolic blood pressure <140 mmHg, diastolic blood pressure <90 mmHg) was seen in only 6.4% of the study participants. Values of both the mean systolic and diastolic blood pressures in all subjects were higher than the desired therapeutic levels (P < 0.001). There was a high prevalence in the study population of established but modifiable risk factors of CVD, such as smoking (30.5%), hypercholesterolemia (59.5%) and sedentary lifestyle (43.5%). Lack of therapeutic control of systolic blood pressure was found significantly associated with age, hypercholesterolemia and sedentary lifestyle (P < 0.05). Conclusions Patients being treated at primary health care centres in Pakistan have inadequate control of high blood pressure. Evidence‐based continuous education of primary health care physicians is a necessary intervention for optimizing treatment strategies and achieving better therapeutic control of hypertension in our population.  相似文献   
93.
BACKGROUND: The pathogenesis of some heart diseases has been associated with changes in the balance of certain trace elements. We examined the association of iron, copper and zinc between biological samples (scalp hair, whole blood and urine) and mortality from myocardial infarction (MI) patients of (first, second and third heart attack). METHODS: The biological samples were from 130 MI patients (77 male and 53 female, age range 45-60 years) and 61 healthy age-matched controls (33 male and 28 female). The metals in the biological samples were measured by the flame atomic absorption spectrophotometry, prior to microwave assisted acid digestion. The validity of the methodology was checked by the biological certified reference materials. RESULTS: During this study, 78% of the 32 patients aged >50 years, registered after the third MI attack died. In these subjects the concentration of Fe and Cu were increased by 0.83% and 3.12% in the scalp hair while in blood samples 9.7% and 22.5% were enhanced respectively, as compared to those who tolerated 3rd MI attack (p=0.072). The concentrations of Zn in whole blood and scalp hair samples were lower in MI patients as compared to normal subjects. CONCLUSION: Deficiency of zinc and high concentration of copper and iron may play a role in the development of heart disease.  相似文献   
94.
Hyperhomocysteinemia is an independent risk factor for vascular disease. In order to evaluate relations between hyperhomocysteinemia and endothelial and leukocyte function, the investigators related homocysteine to indices of endothelial function (plasma endothelin-1 [p-ET-1] and intraplatelet levels of the nitric oxide [NO] and prostacyclin mediators 3'-5' guanosine monophosphate [cGMP] and cyclic 3'-5' adenosine monophosphate [cAMP]) and the monocyte-derived inflammatory mediator neopterin in 168 men (mean age 69, range 49-72 years) with disturbed glucose metabolism and a reference group of 52 male subjects (mean age 70, range 61-79 years). Among the 168 patients with disturbed glucose metabolism plasma (p)-homocysteine correlated significantly with age (r=0.20; p<0.01), glycosylated hemoglobin (HbA1c) (r=0.17; p<0.05), triglycerides (r=0.20; p<0.05), intraplatelet GMP (r=0.16; p<0.05), p-ET-1 (r=0.21; p<0.05), and p-neopterin (r=0.31; p<0.001). The correlation between p-homocysteine and p-ET-1 persisted (p<0.01) in multiple regression analysis. Among the 52 reference subjects p-homocysteine correlated significantly with p-ET-1 (r=0.32; p<0.05) and p-neopterin (r=0.37; p<0.01). The correlation between p-homocysteine and p-neopterin persisted (p<0.05) in multiple regression analysis. In conclusion, homocysteine is related to neopterin and endothelin-1 in plasma of subjects with disturbed glucose metabolism and in reference subjects, suggesting that homocysteine exerts its deleterious effects on vascular function through interference with endothelial and leukocyte function.  相似文献   
95.
Plasma endothelin-1, the nitric oxide (NO) mediator intraplatelet cyclic guanosine monophosphate (cGMP), the prostacyclin mediator cyclic adenosine monophosphate (cAMP) and the macrophage derived inflammatory mediator plasma neopterin were measured in men with Type 2 diabetes mellitus (n=91), impaired glucose tolerance (IGT; n=51), previously abnormal glucose tolerance (PAGT; n=20), and 34 healthy control men. Plasma endothelin-1was higher in men with Type 2 diabetes mellitus than in controls [4.1 (1.0-14.3) vs. 2.1 (0.2-8. 7) ng/l; P<0.001). Intraplatelet cGMP was higher in men with PAGT [0. 84 (0.57-2.76) pmol/10(9) platelets; P<0.05], IGT [0.85 (0.48-3.53); P<0.001] and Type 2 diabetes mellitus [0.90 (0.47-3.86); P<0.001] than in controls [0.70 (0.42-1.70]. No differences existed between groups concerning intraplatelet cAMP or plasma neopterin. Plasma endothelin-1 correlated with fasting plasma glucose (r=0.33; P<0.001) and HbA1(c) (r=0.29; P<0.001). In conclusion, elevated plasma endothelin-1 in Type 2 diabetes mellitus and its relationship to glucose and HbA1(c) suggest a putative role for endothelin-1 in diabetic endothelial cell damage. Increased cGMP indicating enhanced production/activity of NO suggests that factors other than reduced NO activity contribute to enhanced platelet aggregation in diabetes.  相似文献   
96.
The present work deals with the development and validation of method for simultaneous determination of antihistaminic drugs in pharmaceutical formulations. A precise, specific and accurate reverse phase-high-performance liquid chromatography method for the simultaneous measurement of aminophylline and chlorpheniramine maleate was developed. The separation of drugs was achieved on C-18 (5 μm, 250×4.6 mm) high-performance liquid chromatography column. The runtime for analysis was 10 min. Mobile phase is mixture containing dilute H2SO4:methanol (60:40% v/v) with flow rate adjusted at 1.5 ml/min. The detection of components was performed at a wavelength of 264 nm. Retention times of aminophylline and chlorphinramine maleate were found to be 2.00 and 3.25 min, respectively. Linearity was found in the range of 16-24 μg/ml for chlorpheniramine maleate and 102.4-153.6 μg/ml for aminophylline with a correlation coefficient of 0.9998 and 0.9996, respectively. High peak purity index of 99.99% indicated the complete separation of analytes in the presence of degradation products is justification of method stability. Linearity, accuracy, specificity, precision and robustness studies were performed for method validation.  相似文献   
97.
Corneal endothelial safety of intracameral preservative-free 1% xylocaine   总被引:1,自引:0,他引:1  
PURPOSE: To evaluate the effect of intracameral preservative-free 1% xylocaine on the corneal endothelium as an adjuvant to topical anaesthesia during phacoemulsification and Acrysof foldable IOL implantation. MATERIAL & METHODS: This is a prospective, controlled, randomised, double-masked study. 106 patients with soft to moderately dense (Grade 1-3) senile cataract and corneal endothelial cell density of >1500/mm2 were randomised to the xylocaine group (n=53) and control group(n=53). Central endothelial specular microscopy and ultrasound corneal pachymetry were performed preoperatively. On the first postoperative day the eyes were evaluated for corneal oedema and Descemet's folds. Ultrasound corneal pachymetry was performed at 1, 3 and 12 months. Specular microscopy was performed at 3 and 12 months. Cell loss was expressed as a percentage of preoperative cell density. Six patients could not complete one year follow-up. Chi-square and paired t test (2 tail) statistical tests were applied for analysis. RESULTS: Four (7.54%) patients in the xylocaine group and 5 (9.43%) in the control group had a few Descemet's folds associated with mild central stromal oedema. Corneal thickness increased from 549.3micro +/- 37.2micro to 555.5micro +/- 36.5micro in the xylocaine group and from 553.1micro +/- 36.2micro to 559.3micro +/- 40.5micro in the control group at the one-month postoperative visit. Thickness returned to the preoperative level in xylocaine group 549.6micro +/- 34.5micro and control group 554.7micro +/- 41.1micro at three months. (P=0.484) The percentage of cell loss was 4.47 +/- 2.53% in the xylocaine group and 4.49 +/- 3.09% in the control group at one year. (P=0.97) CONCLUSION: Intracameral preservative-free 1% xylocaine does not appear to affect corneal endothelium adversely during phacoemulsification.  相似文献   
98.
99.
Objective.The Verbal Numerical Scale (VNS) for rating pain isbounded between 0 (= no pain) and 10 (= worst pain imaginable). Wehypothesized that the limitations inherent to this boundary when ratingextremely painful stimuli may be identified by integrating the VNS with anunbounded score such as magnitude estimation of relative change. Methods.Volunteers received stimuli of increasing current via cutaneous electrodesuntil they rated > 5 on the VNS scale. This stimulus, termed S, wasarbitrarily assigned a magnitude estimate of 100%. Then, stimuli of varyingcurrents were delivered; two were 10 mA and 20 mA higher than S(S+10 and S+20), two were 1/2 of the current for the Sstimulus (S1/2), and one was at the original current(Srepeat). The pain elicited by each stimulus was scored inproportion to the S stimulus. The extrapolated VNS score (VNSext)was determined by multiplying this magnitude estimate (%) by the VNS score forS. Main Results.Seventy percent of the stimuli with higher intensitythan S generated a VNSext score above 10. The mean magnitudeestimations for S+10 and S+20 were 186% and 242%: theygenerated mean (median) VNSext values of 12.4 [12] and16.2 [14], respectively (p = 0.019 for the differencebetween them by Wilcoxon signed rank test). Conclusions.The combineduse of VNS and magnitude estimation confirmed that the ceiling of the boundedpain scale may significantly limit a patient's ability to describe a newpain stimulus. VNSext may provide a means of overcoming thislimitation.  相似文献   
100.
We report a case of a benign multicystic mesothelioma, which presented as a fungating mass through the anterior abdominal wall and arose in a cesarean-section scar without direct peritoneal involvement. A wide local excision was done and the diagnosis was confirmed by histopathology and immunohistochemistry. The postoperative course was uneventful and the patient is asymptomatic at 3 years' follow-up. Although a history of previous abdominal surgery has been reported in a patient with benign multicystic mesothelioma, to the best of our knowledge, there is no report of a benign multicystic mesothelioma arising in a cesarean-section scar or presentation as a fungating skin mass. This unusual presentation may point to a traumatic or inflammatory etiology, although seeding of the wound during the previous surgeries is a more likely postulate. A pertinent review of the literature on benign multicystic mesothelioma is also presented.  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