Receptor binding occurrence and plasma levels of natriuretic peptides in response to sympathectomy

In the present investigation the relationship between the sympathetic nervous system and the endocardial levels of receptor binding sites for natriuretic peptides and the plasma content of atrial natriuretic peptide were analyzed in rats. In order to destruct the cardiac sympathetic nerve terminals, chemical sympathectomy with 6-hydroxydopamine was made in parallel with intravenous measurements of blood pressure and heart frequency. By use of immunohistochemical and enzyme-linked-immunosorbent techniques the expression of tyrosine hydroxylase-positive sympathetic nerve terminals and plasma levels of pro-atrial natriuretic peptide were determined, respectively. The occurrence of receptor binding sites for natriuretic peptides was examined by in vitro receptor autoradiography. In contrast to the marked occurrence of natriuretic peptide receptor binding sites seen in the ventricular endocardium of control rats, the sympathectomized rats exhibited a decreased number of binding sites for natriuretic peptides in the endocardium of both the right and left chambers. Interestingly, this was found in parallel with a significant decrease of systolic and diastolic blood pressure and increased plasma levels of pro-atrial natriuretic peptide in the treated group of rats. These findings, together with those in previous studies, give support to an idea that one part of the blood pressure-decreasing effects, seen in patients treated with beta-adrenergic blockade, might be through a reduction of the natriuretic clearance receptor C, then giving rise to increased levels of atrial natriuretic peptide.     

Natriuretic peptide expression in the heart of the TTR-ANP transgenic mouse-Comparison to the normal heart

The transgenic mice, TTR-ANP, carrying a fusion gene comprising the transthyretin promoter and the atrial natriuretic peptide (ANP) structural sequence, are known to have elevated ANP plasma levels as well as lowered blood pressure levels. On the other hand, it is not known whether these transgenic mice show changed natriuretic peptide (NP) expression patterns in the heart. Therefore, we examined the distribution of NPs in the myocardium and the conduction system of transgenic mice overexpressing ANP, as well as in wild-type littermates. The hearts were serially sectioned and processed for immunohistochemistry, with antisera against ANP and brain natriuretic peptide (BNP). Florescence microscopy was performed for qualitative analysis. Immunoreactivity for ANP and BNP was detected to a similar degree in the conduction system of both transgenic and wild-type mice. The nodal tissues never exhibited immunoreactions for ANP or BNP, whereas Purkinje fibers of the atrioventricular junctional tissue, bundle branches, and the peripheral Purkinje fiber network exhibited specific immunoreactivity. Atrial and ventricular myocytes of both transgenic and wild-type mice exhibited ANP and BNP to a similar extent. This is the first study examining the expression pattern of NPs in the cardiac conduction system of the mouse as well as the pattern of ANP and BNP expression in the conduction system of TTR-ANP transgenic mice and its wild-type siblings. The findings in this study suggest that ectopic ANP expression and release do not repress cardiac production of ANP.     

基于Hilbert谱的心率变异信号时频分析方法

心率变异性(heart rate variability,HRV)信号的频域分析方法是用来表征自主神经调控信息的基本方法。为了评估自主神经系统功能及对心血管活动的影响,提出一种基于Hilbert时频谱的HRV信号的时频特征提取和分析的新方法。对HRV信号进行希尔伯特-黄变换(Hilbert-Huang transform,HHT)以获得HRV信号Hilbert时频谱,依据短时程HRV信号的线性频域分析指标,得到不同生理频带的Hilbert能量棒形图,提取总能量、各生理频带的能量和其归一化能量以及生理频段的能量比值作为评价心率变异性的时频特征。对MIT-BIH数据库的年轻人、老年人样本和健康人、心衰病人样本的HRV信号分析表明,基于Hilbert谱的时频特征的区分性能好,有较清晰的生理意义,能反映人的生理病理变化,为短时程HRV信号分析提供了一种有效方法。     

Expression of brain natriuretic peptide in the rat heart studies during heart growth and in relation to sympathectomy

Brain natriuretic peptide (BNP) might be of importance during heart development and is described to be increasingly expressed in congestive heart failure and to affect the progress of this condition. However, details in the normal expression of BNP are still unclear in various parts of the adult and growing heart, including the conduction system. In this study, we investigated the expression of BNP in relation to that of atrial natriuretic peptide (ANP) in the growing as well as in the adult rat heart. The effects of chemical sympathectomy in adult rats were also examined. Contrary to previous BNP immunohistochemical studies, the BNP antiserum was preabsorbed with an excess of ANP before staining to abolish the crossreactivity with ANP. There was a pronounced BNP immunoreaction in the auricles, the trabeculated ventricular walls, and the peripheral parts of the conduction system at 0-1 days postnatally. The degree of immunoreaction gradually decreased with increasing age. A similar developmental pattern was seen concerning ANP expression, but the magnitude of the latter clearly exceeded that for BNP. Immunoreaction for BNP was never detected in the atrioventricular (AV) node and AV bundle at any stage. In contrast to the situation for ANP previously observed, no obvious changes in BNP immunoreaction patterns were observed in response to sympathectomy. This is the first study to thoroughly demonstrate the expression of BNP in the various regions of the rat heart during growth and in the normal and sympathectomized adult stage. The observations are related to possible functions of natriuretic peptides in the growing and adult heart.     

Role of the central and peripheral nervous system in the ovarian function

This review attempts to give a comprehensive overview of ovarian innervation, considering the whole nervous system and its different levels that may modify the ovarian function. The connection between the ovary and the central nervous system through the autonomic pathways, including the peripheral ganglia, is highlighted. The evidence obtained over the last years highlights the role of the superior ovarian nerve (SON) in the ovarian phenomena. Besides, the effect on the ovary of conventional neurotransmitters and others such as indolamines and peptides, which have been found in this organ, are discussed. Various reproductive diseases have been studied almost exclusively from the endocrine point of view. It is evident that a better knowledge about the role of the neural factors involved in the ovarian physiology may facilitate the understanding of some of these. A review of the concepts and an update of some experimental designs is made that permits clarifying several aspects of the relationship between the neural system and the ovary. At present, there is no doubt that the innervation of the ovary is involved in several physiological aspects of this gland function. However, the relationship of some levels of the nervous system and the ovary offer a wide avenue for future research.     

A fuzzy expert system to increase accuracy and precision in measurement system analysis

In this paper, we have presented the first proposal to apply measurement system analysis (MSA) in fuzzy environment. Nowadays, because the quality control techniques are applied a lot in manufacturing, research and development environments, many decisions are made in processes and equipment evaluation, control, and improvement. Besides, the philosophy of measurement system analysis (MSA) depends on measurement error which hides true process capability; therefore, it must be implemented prior to any process improvement activities to minimize the measurement errors. Since the capability of each quality system is related to the accuracy of its measurement system, this research develops a novel methodology to increase precision and accuracy of MSA. To do so analyzing measurement systems under fuzziness of indices are investigated to make the environment more realistic. In this article, not only fuzzy measurement system analysis with gauge repeatability and reproducibility (GR&R) index as a triangular fuzzy number is proposed, but a fuzzy measurement system analysis a fuzzy expert system is presented to make more reliable and appropriate decisions. At the end, the applicability of the proposed methodology has been demonstrated within a case study in automotive parts industry to show impact of uncertainty in the reality.     

柔性装配制造系统中生产优化的Petri网方法

本文在基本Ｐｅｔｒｉ网的基础上,给出了一种进行周期性生产的柔性装配制造系统的模型;同时,针对该系统,给出了一个求稳定需求下最佳生产指量的启发式调度方法。     

驾驶室悬置隔振改进设计中DOE技术的研究应用

将正交设计原理与ADAMS中的试验设计（DOE）技术相结合,对某典型商用车全浮式驾驶室悬置隔振系统与主悬架系统的参数匹配问题进行研究。并提出对原车的改进方案,分析结果表明改进方案取得了良好的效果。     

Application of an analytical hierarchy process method and fuzzy compositional evaluation in the expert system of sheet bending design

This article is mainly targeted at establishing a set of Chinese and English expert systems for sheet bending design by using an analytical hierarchy process (AHP) method and fuzzy compositional evaluation using a personal computer. The fuzzy compositional evaluation in conjunction with the analytical hierarchy process method was used to solve the problem of the uncertainty faced by the users during the selection of the processing method. This system combines an AutoCAD graphic mechanism to form a complete system for items ranging from input of the shape and size of the component to the output of the inferred results of the system. At the same time, the fuzzy compositional evaluation and the analytical hierarchy process were employed to make the system more practical.     

航姿参考系统三轴磁强计校正的点积不变法

为改善航姿参考系统中三轴磁强计校正精度,提出了一种基于泊松模型以及矢量点积不变性的校正方法。该方法利用地磁场矢量与一辅助矢量的点积为常数,无需本地地磁场精确数据,能完全确定泊松模型中的12个补偿系数,并能同时实现三轴磁强计的坐标系对准。针对辅助矢量的不同选择对该方法校正结果的影响,在电子罗盘上进行了实验验证及讨论。实验结果表明,该方法可使电子罗盘航向误差均方值减小到0.1°。