Structural changes and cell properties of human ovarian surface epithelium in ovarian pathophysiology

The surface epithelial cells of the ovary, which are modified peritoneal cells, form a single, focally pseudostratified layer. The Müllerian ducts differentiate after invagination of the coelomic mesothelium over the gonadal ridges during the 6th week of embryonic life. On the basis of the embryologically putative Müllerian potential of this epithelium, endometriosis can be explained by coelomic metaplasia from the peritoneum, including ovarian surface epithelium. Some pelvic endometriosis specimens have shown that epithelial cells on the ovary or pelvis are serially changed to endometriotic gland cells. Immunohistochemistry as well as scanning electron microscopy also reinforce the light-microscopical findings. A three-dimensional culture system demonstrated that human ovarian surface epithelial cells exhibited a glandular-stromal structure when they were cocultured with endometrial stromal cells in an estrogen-rich environment. Ovarian carcinomas in the epithelial-stromal category are thought to arise from the surface epithelium and its inclusions. The ovarian surface epithelium is physiologically involved in follicular rupture, oocyte release, and the subsequent repair of follicle wall during reproductive age. Simultaneously, ovulation may cause a loss of integrity of the surface epithelium, followed by accumulation of multiple mutations. The cortical invagination, surface stromal proliferation, and Müllerian differentiation of these cells are likely not to be an early step in the cancer development. However, the inclusion cysts are closely related with carcinogenesis because they are significantly more common in ovaries contralateral to those containing epithelial cancers than in control ovaries. As an in vitro study, ovarian carcinoma cell lines were established from simian virus 40 large T antigen-transformed human surface epithelial cells of the ovary. Further investigations of these cell lines may lead to insights into the preneoplastic and early stages of carcinomas. To clarify the pathogenesis of endometriosis and epithelial ovarian cancer, specifically designed studies of ovarian surface epithelium are required.     

Biology of spermatozoa maturation: an overview with an introduction to this issue

Mammalian spermatozoa undergo morphological, biochemical, and physiological modifications initially in the testis (testicular maturation) and later in the epididymis (epididymal maturation). These maturational changes are commensurate with the functional events that occur in developing germ cells and maturing spermatozoa. This special issue reviews the recent, relevant topics dealing with spermatozoa maturation and focuses on the events that occur in internal components such as the nucleus, the acrosome, the perinuclear theca, the fibrous sheath, and the cytoplasmic droplet as well as the plasma membrane. These structures/elements and the constituent proteins of which they are comprised undergo a variety of sequential modifications starting from their origination in developing germ cells up to epididymal maturation. Several steps of the maturation processes on the sperm plasma membrane are mediated by external enzymes and secretions derived from the epithelium lining of the genital tract. Degradation of some of the constituent proteins and the elimination of defective spermatozoa are controlled by the degradation/recycling system, the ubiquitin system. These maturational modifications are necessary for spermatozoa to become fertilization-competent cells and to be stored safely in the male.     

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.     

动态系统施力函数的识别与控制概论

动态系统施力函数的识别与控制（ＩＣＦＦ）是一个既“老”又“新”的课题。说它“老”是因为机械动力学产生之日起,它就存在;说它“新”是因为迄今为止仍未得到深入的研究。随着现代科学技术的发展,如计算机控制技术、智能控制技术、传感器技术和频谱分析技术的日益成熟,已经有条件对ＩＣＦＦ进行深入研究,而且面对工业化生产再也不能回避研究这一类课题。本文综述了ＩＣＦＦ的研究现状,初步分析了施力函数性质对动态系统响应的影响,给出了八种可用于ＩＣＦＦ的研究方法和途径。     

Decomposition of an ARX model on Laguerre orthonormal bases

In this paper, we propose a new reduced complexity model by expanding a discrete-time ARX model on Laguerre orthonormal bases. To ensure an efficient complexity reduction, the coefficients associated to the input and the output of the ARX model are expanded on independent Laguerre bases, to develop a new black-box linear ARX-Laguerre model with filters on model input and output. The parametric complexity reduction with respect to the classical ARX model is proved theoretically. The structure and parameter identification of the ARX-Laguerre model is achieved by a new proposed approach which consists in solving an optimization problem built from the ARX model without using system input/output observations. The performances of the resulting ARX-Laguerre model and the proposed identification approach are illustrated by numerical simulations and validated on benchmark manufactured by Feedback known as Process Trainer PT326. A possible extension of the proposed model to a multivariable process is formulated.     

Immune system involvement in the regulation of ovarian function and augmentation of cancer

Increasing evidence indicates a role for the immune system and mesenchymal-epithelial interactions in the regulation of ovarian function. Cytokines produced by mesenchymal cells can stimulate development and regression of ovarian structures. We report here that mesenchymal cells releasing surface molecules among epithelial cells--namely vascular pericytes and monocyte-derived cells (MDC)--and intraepithelial T lymphocytes are associated with oogenesis and formation of new primary follicles in both fetal and adult human ovaries. These activated mesenchymal cells interact with the ovarian surface epithelium, which appears to be a source of secondary germ cells and granulosa cells. Activated pericytes and MDC are also associated with stimulation of thecal development during selection of growing secondary follicles from the cohort of primary follicles. However, survival of the dominant follicle during mid-follicular phase selection is associated with a lack of activity of mesenchymal cells and retardation of thecal development, since immature granulosa cells lacking aromatase are unable to resist high levels of thecal androgens. Once the selected follicle matures (late follicular phase), it shows enhanced activity of thecal mesenchymal cells and advanced thecal development. Corpus luteum (CL) development is accompanied by a high activity of vascular pericytes and MDC. In mature CL and CL of pregnancy, luteal MDC and pericytes show a stable (inactive) state. Regression of the CL is associated with regression of pericytes, transformation of MDC into dendritic cells, infiltration by T lymphocytes, and binding of immunoglobulin G to the luteal cells. The immunoglobulin M (IgM) binds to young but not mature luteal cells. In the CL of pregnancy, IgM binds to luteal vessels, but not to luteal cells. Regressing CL shows IgM binding to both luteal cells and vessels. In ovarian cancers, highly activated MDC and sometimes activated pericytes (poorly differentiated carcinomas) are present. IgM binding is similar to that seen in the CL of pregnancy. These data indicate that vascular pericytes, MDC, T cells, and immunoglobulins may play an important role in the regulation of ovarian physiology and contribute to the augmentation of ovarian cancer growth.     

一种电子机箱的结构设计研究

随着军用电子技术的发展,电子设备机箱在航空、航天等领域应用非常的广泛。为了保证机箱能够适应各种飞行条件,研制一种既要保证功能,又要保证可靠性的电子机箱产品是军用电子设备研制必须重视的工作。文中针对实际需求,研究了一种军用电子设备机箱的结构设计。与传统的插板式机箱相比,这种机箱具有刚度大、内部连接可靠性高、重量轻、工艺性好、调试方便、导热能力强等优点。整机通过贯穿的螺栓实现整体固定,其结构刚度大,能够适应严酷航天飞行环境,提高电子设备工作的可靠性和适应性,另外,通过相变热控装置作为整个机箱热沉,达到良好的散热效果。     

多功能智能垃圾桶结构设计和功能实现

目前市场上现有的垃圾箱无法对垃圾进行主动的、有针对性的、初步的分类,而市场上常见的智能垃圾箱仅仅做到了投掷的智能化,严格意义上讲这不属于智能垃圾桶,无法普及且性价比低。因此,基于垃圾的自动检测、区分和存放的目的,采用SolidWorks三维设计、PLC和多传感器技术,从机械设计、功能实现等方面,设计出一款智能垃圾桶,针对金属、纸制品、塑料、玻璃瓶、其他垃圾进行分类。为了验证该垃圾智能检测方案的合理性,研制出试验样机并进行了试验,结果表明:利用该装置,垃圾分类检测的准确度为84.5%,实现垃圾的初步自动分离。该智能垃圾桶的推广和应用不仅能实现资源的二次利用,对于环境保护、智慧城市建设也有积极意义。     

超宽带雷达发射机的结构设计

简要介绍了超宽带雷达发射机的结构组成及工作特点,在此基础上提出了超宽带雷达发射结构的总体设计思想,并着重讨论了低压结构,高压结构和冷却系统设计中的关键问题。     

某机载雷达模拟吊舱结构设计

某机载雷达模拟吊舱是安装于某型歼击机机翼下的机载外挂设备,载机对吊舱的体积、重量、外形有严格的设计要求。由于其工作环境条件恶劣,所以给该机载雷达模拟吊舱结构设计带来较大的难度,文中从吊舱的结构布局、环境控制、舱体设计等方面介绍了该吊舱结构的设计和实现方法。     

Structural parameters identification using improved normal frequency response function method

An improved method that is based on a normal frequency response function (FRF) is proposed in this study in order to identify structural parameters such as mass, stiffness and damping matrices directly from the FRFs of a linear mechanical system. This paper demonstrates that the characteristic matrices may be extracted more accurately by using a weighted equation and by eliminating the matrix inverse operation. The method is verified for a four degrees-of-freedom lumped parameter system and an eight degrees-of-freedom finite element beam. Experimental verification is also performed for a free–free steel beam whose size and physical properties are the same as those of the finite element beam. The results show that the structural parameters, especially the damping matrix, can be estimated more accurately by the proposed method.     

Near-field imaging: some attempts to define an apparatus function

Near-field microscopy is a promising new tool capable of imaging details smaller than the wavelength. The mechanism of imaging is analysed and an overview of the apparatus functions which could be used to define an image quality criterion is given.     

Theoretical bases of the configuration of joint parts

It is shown that the formation of joints is based on the adjustment of two sets of bases, which form a joint module. Each joint module is realized by means of appropriate variants of the base sets to be adjusted.     

浅谈无人机

随着现代武器装备、信息化社会的飞速发展,计算机、人工智能、自动驾驶和信号处理等高新技术的发展以及各种尖端技术新设备的成功研制,军用无人机已发展成为能进行侦察、电子干扰、战场目标毁伤效果评估等多种用途的平台,受到各国的高度重视.本文就军用无人机的发展概况和应用进行概括介绍,并对未来军用无人机的发展趋势作简要预测.     

全光纤干涉系统在测量激光光谱结构特征中的应用

利用自制的全光纤干涉系统,对激光光谱结构特性所引起的干涉条纹幅度变化进行了理论分析和实验证明。首次将全 光纤干涉系统应用于激光光谱的结构分析领域,可能会导致出现一种新的激光光谱测量仪。     

某机载安装架的结构设计与动力学分析

作为机载设备装机的常用附件,机载安装架的结构设计不但要满足复杂装机接口的要求,还应将恶劣环境条件对机载设备的影响降至最低。文中简要介绍了一种集中式机载安装架的结构设计方法,并对随机振动条件下安装架上设备的动态响应以及加速度过载时安装架的强度和位移进行了仿真分析,确保安装架具有很好的隔振效果并满足载机隔振空间要求。     

某机载吊挂天线系统的结构设计与分析

机载吊挂天线具有结构紧凑、接口简单等特点,在机载雷达领域应用较为广泛.在结构设计时应兼顾体积、重量、强度等多方面因素,需要进行全面细致的考虑.文中以某机载吊挂天线为例,针对天线使用的环境要求,简单介绍了该天线系统的结构特点,重点介绍了天线系统的结构组成、热设计及载荷分析等,可为同类天线系统的结构设计提供参考.     

异形真空室壳体的结构强度分析

异形真空薄壳结构在航天、航空产品中的应用越来越广泛,基于减重和可靠性考虑,需要对这一类承受负压的压力容器进行结构强度分析和优化设计。首先应用基于经验的规则设计方法对该结构进行了强度校核。进一步,利用有限元分析软件HyperMesh、Ansys对该异形壳体建立了整体有限元模型。通过分析设计,证明该结构应力分布合理,并采用参数设计方法得到最优壁厚。从结果来看,基于经验的方法和基于有限元分析的方法得到的强度结果接近,但后一种方法不仅能够给出应力、应变的分布云图,而且在优化设计方面的选择也更加灵活。提到的设计方法对该类负压容器的设计具有一定的借鉴作用。