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   90篇
  免费   8篇
  国内免费   1篇
儿科学   1篇
基础医学   12篇
临床医学   8篇
内科学   11篇
神经病学   3篇
外科学   32篇
预防医学   3篇
眼科学   3篇
药学   10篇
中国医学   1篇
肿瘤学   15篇
  2022年   4篇
  2021年   3篇
  2020年   1篇
  2018年   4篇
  2017年   5篇
  2016年   3篇
  2015年   5篇
  2014年   6篇
  2013年   8篇
  2012年   11篇
  2011年   5篇
  2010年   10篇
  2009年   5篇
  2008年   3篇
  2007年   5篇
  2006年   1篇
  2005年   4篇
  2004年   6篇
  2003年   2篇
  2002年   2篇
  2001年   1篇
  2000年   1篇
  1998年   1篇
  1996年   2篇
  1987年   1篇
排序方式: 共有99条查询结果,搜索用时 15 毫秒
1.
Tubulointerstitial fibrosis is common with ageing and strongly prognostic for ESRD but is poorly captured by eGFR or urine albumin to creatinine ratio (ACR). Higher urine levels of procollagen type III N-terminal propeptide (PIIINP) mark the severity of tubulointerstitial fibrosis in biopsy studies, but the association of urine PIIINP with CKD progression is unknown. Among community-living persons aged ≥65 years, we measured PIIINP in spot urine specimens from the 1996 to 1997 Cardiovascular Health Study visit among individuals with CKD progression (30% decline in eGFR over 9 years, n=192) or incident ESRD (n=54) during follow-up, and in 958 randomly selected participants. We evaluated associations of urine PIIINP with CKD progression and incident ESRD. Associations of urine PIIINP with cardiovascular disease, heart failure, and death were evaluated as secondary end points. At baseline, mean age (±SD) was 78±5 years, mean eGFR was 63±18 ml/min per 1.73 m2, and median urine PIIINP was 2.6 (interquartile range, 1.4–4.2) μg/L. In a case-control study (192 participants, 231 controls), each doubling of urine PIIINP associated with 22% higher odds of CKD progression (adjusted odds ratio, 1.22; 95% confidence interval, 1.00 to 1.49). Higher urine PIIINP level was also associated with incident ESRD, but results were not significant in fully adjusted models. In a prospective study among the 958 randomly selected participants, higher urine PIIINP was significantly associated with death, but not with incident cardiovascular disease or heart failure. These data suggest higher urine PIIINP levels associate with CKD progression independently of eGFR and ACR in older individuals.  相似文献   
2.
Acute vascular rejection (AVR), in particular microvascular thrombosis, is an important barrier to successful pig‐to‐primate xenotransplantation. Here, we report the generation of pigs with decreased tissue factor (TF) levels induced by small interfering (si)RNA‐mediated gene silencing. Porcine fibroblasts were transfected with TF‐targeting small hairpin (sh)RNA and used for somatic cell nuclear transfer. Offspring were analyzed for siRNA, TF mRNA and TF protein level. Functionality of TF downregulation was investigated by a whole blood clotting test and a flow chamber assay. TF siRNA was expressed in all twelve liveborn piglets. TF mRNA expression was reduced by 94.1 ± 4.7% in TF knockdown (TFkd) fibroblasts compared to wild‐type (WT). TF protein expression in PAEC stimulated with 50 ng/mL TNF‐α was significantly lower in TFkd pigs (mean fluorescence intensity TFkd: 7136 ± 136 vs. WT: 13 038 ± 1672). TF downregulation significantly increased clotting time (TFkd: 73.3 ± 8.8 min, WT: 45.8 ± 7.7 min, p < 0.0001) and significantly decreased thrombus formation compared to WT (mean thrombus coverage per viewing field in %; WT: 23.5 ± 13.0, TFkd: 2.6 ± 3.7, p < 0.0001). Our data show that a functional knockdown of TF is compatible with normal development and survival of pigs. TF knockdown could be a valuable component in the generation of multi‐transgenic pigs for xenotransplantation.  相似文献   
3.

Summary

Here we report that abnormal brain white matter and, to a lesser extent, albuminuria are associated with reduced bone mineral density in the hip, spine, and total body in men and women. These findings may explain the increased hip fracture risk reported in some studies in association with microvascular disorders.

Introduction

Markers of microvascular disease have been individually associated with increased risk of osteoporotic fractures in some studies. Here, we examine whether these markers are associated with reduced bone mineral density (BMD) individually and together.

Methods

BMD testing using dual x-ray absorptiometry of the hip, lumbar spine, and total body was performed in 1473 participants from the Cardiovascular Health Study (mean age ~ 78 years): 1215 were assessed for urinary albumin-creatinine ratio, 944 for abnormal white matter disease (AWMD) by brain MRI, and 541 for retinal vascular disease with fundus photographs. Linear regression models were used to evaluate the cross-sectional association of each marker with BMD accounting for potentially confounding factors.

Results

AWMD was associated with lower hip, spine, and total body BMD in women (β ?3.08 to ?4.53; p < 0.01 for all) and lower hip and total body BMD in men (β ?2.90 to ?4.24; p = 0.01–0.03). Albuminuria was associated with lower hip (β ?3.37; p = .05) and total body (β ?3.21; p = .02) BMD in men, but not in women. The associations of AWMD and albuminuria with BMD persisted with mutual adjustment and appeared to be additive to each other. Retinal vascular disease was not associated with BMD in men or women.

Conclusion

AWMD and, to a lesser extent, albuminuria were independently associated with lower BMD, suggesting that microvascular disease may play a role in the pathogenesis of reduced BMD. These findings need to be confirmed by longitudinal studies.
  相似文献   
4.
A robust method to facilitate rapid laser microdissection and pressure catapulting (LMPC) coupled with direct polymerase chain reaction (dPCR) to eliminate the need for extraction of DNA before a PCR-based assay is described. This sequential LMPC-dPCR method is rapid and decreases the number of processing steps, reducing the chance of tissue loss and contamination.  相似文献   
5.

Introduction

Small-bowel obstruction (SBO) requiring adhesiolysis is a frequent and costly problem in the United States with limited evidence regarding the most effective and safest surgical management. This study examines whether patients treated with laparoscopy for SBO have better 30-day surgical outcomes than their counterparts undergoing open procedures.

Methods

Patients with a diagnosis of adhesive SBO were selected from the ACS National Surgical Quality Improvement Program database from 2005 to 2010. Cases were classified as either laparoscopic or open adhesiolysis groups using Common Procedural Terminology codes. Chi square and Student’s t test were used to compare patient and surgical characteristics with 30-day outcomes, including major complications, incisional complications, and mortality. Factors with p < 0.1 were included in the multivariable logistic regression for each outcome. A propensity score analysis for probability of being a laparoscopic case was used to address residual selection bias. A two-sided p value <0.05 was considered significant.

Results

Of the 9,619 SBO included in the analysis, 14.9 % adhesiolysis procedures were performed laparoscopically. Patients undergoing laparoscopic procedures had shorter mean operative times (77.2 vs. 94.2 min, p < 0.0001) and decreased postoperative length of stay (4.7 vs. 9.9 days, p < 0.0001). After controlling for comorbidities and surgical factors, patients having laparoscopic adhesiolysis were less likely to develop major complications [odds ratio (OR) = 0.7, 95 % confidence interval (CI) 0.58–0.85, p < 0.0001] and incisional complications (OR = 0.22, 95 % CI 0.15–0.33, p < 0.0001). The 30-day mortality was 1.3 % in the laparoscopic group versus 4.7 % in the open group (OR = 0.55, 95 % CI 0.33–0.85, p = 0.024).

Conclusions

Laparoscopic adhesiolysis requires a specific skill set and may not be appropriate in all patients. Notwithstanding this, the laparoscopic approach demonstrates a benefit in 30-day morbidity and mortality even after controlling for preoperative patient characteristics. Given these findings in more than 9,000 patients and consistent rates of SBO requiring surgical intervention in the United States, increasing the use of laparoscopy could be a feasible way of to decrease costs and improving outcomes in this population.  相似文献   
6.
PURPOSE: To investigate the ocular penetration of acyclovir and its prodrugs following systemic administration and to elucidate the mechanism of penetration. METHODS: Hydrophilic peptide prodrugs of acyclovir were infused intravenously in New Zealand albino rabbits over 45 min at a dose equivalent to 30 mmoles/kg acyclovir. Aqueous and vitreous humor samples were obtained utilizing ocular microdialysis and blood samples were obtained from the mid ear vein using a cannula. RESULTS: The plasma bioavailability for acyclovir, valacyclovir and val-valacyclovir were similar with area under curve values being 896.24 (+/-143.58), 776.54 (+/-197.52), 824.69 (+/-217.43) min x micromoles/L respectively. Anterior segment area under curve values were 53.70 (+/-35.58), 139.85 (+/-9.43) and 291.05 (+/-88.13) min x micromoles/L respectively while the mean residence time values were 46.47 (+/-24.94), 76.30 (+/-7.24) and 188.39 (+/-80.73) min respectively. Vitreous levels of the prodrugs were not measurable. CONCLUSIONS: The valine and valine-valine ester prodrugs of ACV penetrated the anterior segment of the eye much better than acyclovir alone, probably via a carrier mediated transport mechanism.  相似文献   
7.
Developing novel antimicrobial drugs is increasingly important in the modern pharmaceutical industry. A series of novel 3‐chloro‐4‐[4‐(2‐oxo‐2H‐chromen‐4‐ylmethoxy)phenyl]‐1‐phenylazetidin‐2‐ones 5a–o have been synthesized from 4‐bromomethylcoumarins 1a–e and 4‐aryliminomethyl‐phenols 3a–c . These compounds were screened for their in‐vitro antibacterial activity against two Gram‐positive (Staphylococcus aureus and Vancomycin resistant enteroccoccus) and two Gram‐negative (Escherichia coli and Shigella dysentery) bacterial strains and antifungal activity against Aspergillus fumigatus, Candida albicans, and Penicillium. Results revealed that compounds 5c , 5f , 5h , 5j , and 5m showed excellent activity against a panel of microorganisms. The brine‐shrimp bioassay was also carried out to study their in‐vitro cytotoxic properties and two compounds, 5h and 5m , possessing LD50 = 7.154×10–4 M and 5.782×10–4 M, respectively, displayed potent cytotoxic activity against Artemia salina. The presence of a chlorine group in the coumarin moiety, its effect on their antibacterial, antifungal, and cytotoxic activities is discussed. All newly synthesized compounds were characterized by elemental analysis, IR, 1H‐NMR, 13C‐NMR, and MS.  相似文献   
8.
Critical care physicians are frequently confronted with intoxicated patients who have used street drugs. In the last decade there has been an upward trend in the use of these substances, particularly amongst adolescents and young adults in large urban areas. In excess quantities all street drugs can lead to critical illness. Early and appropriate medical attention by emergency medicine physicians and intensivists can improve outcomes. In this review article we intend to familiarize critical care physicians with the most common street drugs such as amphetamines, ecstasy, cocaine, gamma hydroxybutyrate, opioids, and phencyclidine.  相似文献   
9.

Background

Chronic kidney disease (CKD) is strongly associated with peripheral artery disease (PAD). Detection of subclinical PAD may allow early interventions for or prevention of PAD in persons with CKD. Whether the presence of atherosclerotic plaque and femoral intima-media thickness (IMT) are associated with kidney function is unknown.

Methods

We performed a cross-sectional observational study of 1029 community-living adults. We measured superficial and common femoral artery IMT and atherosclerotic plaque presence by ultrasound. Estimated glomerular filtration rate (eGFR; continuous) and eGFR <60 mL/min/1.73 m2 (binary) were evaluated as outcomes.

Results

Mean age was 70 ± 10 years, mean eGFR was 78 ± 17 mL/min/1.73 m2, and 156 (15%) individuals had eGFR <60 mL/min/1.73 m2; 260 (25%) had femoral artery plaque. In models adjusted for demographics and cardiovascular risk factors, individuals with femoral artery plaque had mean eGFR approximately 3.0 (95% confidence interval, ?5.3 to ?0.8) mL/min/1.73 m2 lower than those without plaque (P < .01). The presence of plaque was also associated with a 1.7-fold higher odds of eGFR <60 mL/min/1.73 m2 (95% confidence interval, 1.1-2.8; P < .02). Associations were similar in persons with normal ankle-brachial index. The directions of associations were similar for femoral IMT measures with eGFR and CKD but were rendered no longer statistically significant with adjustment for demographic variables and cardiovascular disease risk factors.

Conclusions

Femoral artery plaque is significantly associated with CKD prevalence in community-living individuals, even among those with normal ankle-brachial index. Femoral artery ultrasound may allow evaluation of relationships and risk factors linking PAD and kidney disease earlier in its course.  相似文献   
10.
Safety of transesophageal echocardiography in patients who are obese.   总被引:3,自引:0,他引:3  
Patients with obesity tend to have a higher incidence of hypertension, coronary artery disease, and sleep apnea, conditions that could potentially predispose to complications during transesophageal echocardiography (TEE). In addition, patients who are obese are more likely to have oxygen desaturation during upper gastrointestinal endoscopy. However, the safety of TEE in a large cohort of patients with obesity has not been reported. Thus, the safety of TEE in 341 patients who were obese (body mass index >/= 27.5 kg/m(2), mean 41.0 +/- 10.3) and in 323 control patients who were not obese was compared. Minor complications (ie, complications of a transient duration and requiring no or only simple intervention) occurred with equal frequency in the control and obese groups (16.5% vs 16.7%, P = not significant). Transient oxygen desaturation did not differ between the control versus obese group (2.5% vs 3.8%, P = not significant), but was more common (6.7%) in a subgroup (n = 150) of patients who were morbidly obese as compared with control patients (P <.05). Transient hypotension was observed in 3.5% of the obese group compared with 7.4% in the control group (P <.05). However, transient hypertension was noted in 10.6% of the patients who were obese compared with 6.5% in the control group (P =.072). A major complication occurred in 2 patients with obesity, one who required vasopressor medication for persistent hypotension and another needing pharmacologic rate control of atrial fibrillation. One patient in the control group had provoked supraventricular tachycardia and angina. No deaths occurred in either group. Subjective tolerance for the procedure was similar (P = not significant) in both groups with 84% of patients with obesity having good to excellent tolerance compared with 88% in that of the control group. Thus, TEE can be safely performed in patients who are obese.  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