首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
2.
This open-label, randomized, placebo lead-in, three-treatment crossover study in 19 hypogonadal men (27-82 years of age) evaluated dose proportionality of serum testosterone concentrations with application of one or two investigational transdermal testosterone systems for application to the arm or torso. Testosterone in vivo kinetics profiles were determined using DeMonS, a recently developed numerical deconvolution method that estimates drug absorption at different time intervals and/or drug disposition model parameters. After application of the investigational transdermal systems, the mean serum testosterone, dihydrotestosterone, estradiol, and free testosterone concentrations were elevated to normal levels. Treatment allowed approximation of the normal circadian pattern of endogenous testosterone secretion, and the increase in serum testosterone concentrations was proportional to the surface area of systems applied. The investigational transdermal system provided effective testosterone replacement therapy as judged by pharmacokinetic parameters.  相似文献   

3.
高炉雷达料面成像系统的设计与实现   总被引:5,自引:0,他引:5  
针对高炉生产现场实时确切掌握高炉内部料面形状分布和变化的迫切需要,建立基于图像处理的高炉料面在线检测模型,并基于雷达物位计、数据采集卡、PLC控制系统和上位机进行了系统集成。综合曲线放样建模和曲面拟合或插值的优缺点,建立基于专家系统带权值的双算法综合料面生成模型,采用最小二乘法曲面拟合算法和NURBS曲面全局插值算法进行曲面拟合,生成料面,通过合理选取雷达数量,选定雷达检测点,最大程度地使雷达测量结果逼近实际料面情况。  相似文献   

4.
Due to the narrow therapeutic range of theophylline, plasma concentrations of this drug are monitored in patients undergoing chronic therapy. Slow-release preparations avoid the fluctuations in plasma levels and improve patient compliance. In this study, we have compared the pharmacokinetic profiles of a theophylline slow-release tablet and a syrup form, when administered in multiple doses to healthy adult volunteers. The classification based upon releasing patterns is confirmed.  相似文献   

5.
Nonhyperfunctioning adrenal lesions such as cysts, myelolipomas, adrenal haemorrhage, adenoma and metastases are described. Definitive imaging features that help characterize adrenal cysts, myelolipomas and adrenal haemorrhage are illustrated and the differentiation of benign from malignant adrenal lesions using an algorithmic approach based on lipid sensitive imaging is provided.  相似文献   

6.
Globally, men have not shared equally with women the responsibility for fertility regulation. While family planning efforts have been directed almost exclusively toward women, the lack of male involvement may also reflect the limited options available to men. Current methods for men are either coitus-dependent, such as the condom or withdrawal, or permanent, such as vasectomy. The 20-year history of social science research on male contraceptive methods is examined here in terms of the human and method factors related to the acceptability of hypothetical methods and the prevalence of use of existing methods. New male methods, particularly if reversible, may alter men's willingness to accept or share responsibility for the control of fertility. Research opportunities in the areas of gender, decision-making, communication, health education, and service delivery will be enhanced when methods for women and men are comparable.  相似文献   

7.
The Faculty of Biomedical and Health Sciences at RMIT has been developing an on-line health education system using a systems thinking approach, to create a learning environment whose basis is supported by Information Technology (IT). The centre-piece of this system is the Faculty Learning Centre, which has been created, both in space and layout, to promote collaborative learning between the students, so that the educator is physically assimilated with the student body. This facility is supplemented by the Faculty WWW server, which has been the main vehicle for course material dissemination to students. To ensure an effective on-line teaching environment, the position of an on-line facilitator has been created, whose responsibilities include both the continual evaluation of the system and the implementation of appropriate system changes. Aspects have included the production of a staff development training program and extensive user documentation. This paper discusses the systems thinking approach used to implement this integrated on-line system, and the establishment of explicit educational rationales in the use of IT to support learning strategies. Some examples of the on-line educational programs are also presented.  相似文献   

8.
Cyclic GMP-dependent protein kinase (cGMP kinase) is the major receptor protein for cGMP in vascular smooth muscle. Vascular smooth muscle cells (VSMC) isolated from the rat aorta express type I cGMP kinase at high levels, but expression decreases markedly upon passage of the cells. In primary or early passage, the expression of cGMP kinase is lowest when cells are plated at low density as assessed by immunological and Northern analyses. Expression increases at confluence and is maintained in postconfluent cultures. With repeated passaging, however, the levels of cGMP kinase decrease even in confluent and postconfluent cultures so that after several passages enzyme levels are undetectable. The decrease in expression in passaged cells is not due to exposure to serum-derived growth factors, but rather on the repeated exposure of cells to conditions in which cell density is reduced (i.e., subculturing). These results indicate that aortic VSMC grown at low density or those repetitively passaged have reduced expression of cGMP kinase, and thus may not represent appropriate cultures with which to investigate the role of nitric oxide and cGMP in VSMC function.  相似文献   

9.
Nuclear medicine remains a vibrant and dynamic medical specialty because it so adeptly marries advances in basic science research, technology, and medical practice in attempting to solve patients' problems. As a physicist, it is my responsibility to identify or design new instrumentation and techniques, and to implement, validate, and help apply these new approaches in the practice of nuclear medicine. At Johns Hopkins, we are currently in the process of purchasing both a single-photon/coincidence tomographic imaging system and a dedicated positron emission tomography (PET) scanner. Given the exciting advances that have been made, but the conflicting opinions of manufacturers and colleagues alike regarding "best" choices, it seemed useful to review what is new now, and what is on the horizon, to help identify all of the important considerations in the design and selection of an imaging system. It is important to note that many of the "advances" described here are in an early stage of development, and may never make it to routine clinical practice. Further, not all of the advances are of equal importance, or have the same degree of general clinical applicability. Please also note that the references contained herein are for illustrative purposes and are not all-inclusive; no implication that those chosen are "better" than others not mentioned is intended.  相似文献   

10.
Allergy to latex has been increasing in both the healthcare consumer and healthcare provider populations over the past decade. Realizing that sensitivity/allergy to latex is an issue for both patients and staff, the authors created an interdisciplinary task force to address latex safety in a healthcare agency that provides care within inpatient, public health, and outpatient settings. In this article, the authors discuss allergic response to latex and testing for latex sensitivity as well as latex allergy in the general population, among patient populations, and among healthcare providers. The authors outline the development of a latex-free product cart, an agency policy and procedure, and staff and patient education strategies.  相似文献   

11.
12.
Minimal access surgery (MAS) is bringing about a revolution in surgical practice with certain operations being almost wholly carried out using MAS techniques in some countries. This paper describes the development, current status and future prospects of MAS from a technological perspective.  相似文献   

13.
BACKGROUND: The aim of this study was to establish the feasibility, safety, and diagnostic accuracy of the dipyridamole echocardiography test in patients with severe aortic valve stenosis for noninvasive detection of coexisting coronary artery disease. METHODS: The high-dose dipyridamole echocardiography test was performed in 52 patients with severe aortic stenosis; all patients also underwent coronary angiography, independent of test results, before cardiac operation. RESULTS: The dipyridamole echocardiography test was completed without major complications. One patient had transient atrial fibrillation that was reversed by aminophylline. Thirty-one patients (60%) had a negative test result; all had normal coronary arteries. Ten of the 21 patients (48%) with a positive test result had coexisting coronary artery disease. The positive predictive value of the dipyridamole echocardiography test for detection of coronary disease in patients with severe aortic stenosis was 48%. The negative predictive value was 100%. The sensitivity was 100% and the specificity was 74%. CONCLUSIONS: Dipyridamole echocardiography is a safe and feasible tool in patients with severe aortic stenosis eligible for a cardiac operation. A negative test result reliably rules out a significant stenosis, whereas a positive one is much less accurate in predicting coronary artery disease.  相似文献   

14.
OBJECTIVE: Previous studies of surgical treatment for acromegaly have used varied criteria for 'cure', but elevated GH levels are considered to be associated with continuing disease activity. We wished to analyse the results of transsphenoidal pituitary surgery for acromegaly and assess the longer-term outcome for patients not offered further treatment when post-operative levels of GH < 5 mU/l were achieved. DESIGN: We studied a retrospective group of patients who underwent transsphenoidal surgery for acromegaly at St Bartholomew's Hospital between 1985 and 1993. PATIENTS: One hundred consecutive patients (53 male, mean age 46 years, range 18-68 years) undergoing transsphenoidal surgery for acromegaly were assessed. The patients were followed for a mean of 3.8 years (range 0.5-8 years) after operation. MEASUREMENTS: GH levels are represented as a mean value from a four-point day curve taken at 0830, 1300, 1700 and 1900 h. ACTH reserve was assessed basally and, if this was normal, with the insulin tolerance or glucagon tests. TSH, T4, PRL, LH, FSH, testosterone or oestradiol and plasma and urine osmolality were also measured. RESULTS: Post-operatively, 42% of patients achieved a mean GH level of < 5 mU/l. The success of surgery was related to the preoperative GH level; 65% of the patients with preoperative GH levels < 20 mU/l but only 18% of the patients with GH levels > 100 mU/l achieved post-operative GH values < 5 mU/l. In addition, tumour size influenced the outcome of surgery with 61% of patients with a microadenoma but only 23% of patients with a macroadenoma achieving post-operative GH levels of < 5 mU/l. Of the 42 patients considered in remission post-operatively (mean GH < 5 mU/l), 32 were available for long-term follow-up and were not offered any further treatment: only one of these has shown evidence of mild biochemical recurrence after a mean follow-up of 3.8 years (range 0.5-8). There were no peri-operative deaths. Two patients required surgical repair for CSF leaks and there were eight documented cases of meningitis. Permanent diabetes insipidus was noted in eight patients post-operatively. New anterior pituitary deficiency occurred in 21% of patients following surgery; 73% had unaltered pituitary function and in 6% recovery of partial hypopituitarism was noted. CONCLUSIONS: The stated outcome of surgery depends on the criteria adopted. Safe GH levels (mean levels < 5 mU/l) can be achieved in 42% of an unselected series of patients with acromegaly and if the tumour is a microadenoma this figure rises to 61%. Based on the current evidence it is safe not to offer further treatment to those patients in whom post-operative GH < 5 mU/l are achieved.  相似文献   

15.
冀东1^#水泥生产线水泥包装子系统改造,采用了A-B PLC5系列控制器,本文着重介绍该系统的硬件配置和功能,以及改造需解决的问题和软件功能的实现。  相似文献   

16.
17.
18.
为提高超混沌吸引子的拓扑结构的复杂性,构造了一个新的超混沌系统,对新的系统进行了理论分析和计算机仿真,并设计了一个模拟电路对系统进行实验,实验所得相图与数值仿真一致,是具有四翼吸引子的超混沌系统,从而证明了理论分析和数值仿真的正确性.  相似文献   

19.
A newborn presented with a cerebral ganglioglioma. This is a rare diagnosis in a neonate. The imaging appearance (hyperdense on CT, hyperintense on T1-weighted and hypointense on T2-weighted MRI) is very unusual for this type of tumor.  相似文献   

20.
为提高铁钢界面系统的运行效率,以秦皇岛首秦金属材料有限公司铁钢界面鱼雷罐为研究对象,在解析其周转过程的基础上,建立鱼雷罐周转物理模型,设计出分区域鱼雷罐管理方式;根据供求平衡和鱼雷罐等待时间最小原则,建立鱼雷罐周转个数优化模型;最终实现鱼雷罐的计算机化管理。将系统应用于生产,取得了明显的效果。  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