小鼠睾丸组织玻璃化保存的初步实验研究

对于无法取精的不育患者或患有癌症需放化疗的青春期前男孩,睾丸组织冷冻是潜在的有效保存生育力的方法.本文对小鼠块状睾丸组织的玻璃化保存方法进行了研究,运用差示扫描量热仪,对在不同体积分数保护剂中浸泡了不同时间后的小鼠块状睾丸组织进行热分析,随后对其进行玻璃化冻存,并将睾丸组织慢速冷冻保存与玻璃化冻存进行了对比.结果表明:...     

食品玻璃化保存的研究进展及存在的问题

食品的低温玻璃化保存是近十年发展起来的一门新学科。对食品玻璃化保存的状做了简单的介绍,分析了ＷＬＦ和Ａｒｒｈｅｎｉｕｓ关系式在应用于食品体系生化反应方面存在的问题,探讨了在食品部分玻璃化保存下Ｔ．Ｔ．Ｔ概念和酶的稳定性,并指出实现食品低温玻璃化保存需要新的冻结与解决方法。     

冻结食品的玻璃化保存

冻结食品的玻璃化保存是近十几年在国外发展起来的一门新学科。本文对其理论基础及研究方面作了简要介绍,并着重指出了研究中存在的问题和今后进一步研究的方向。     

成纤维细胞玻璃化保存的初步实验研究

成纤维细胞是构建组织工程化真皮的种子细胞,实现成纤维细胞的低温保存对成功保存组织工程化真皮有着重要的意义.采用不同组成及浓度的玻璃化溶液对成纤维细胞进行玻璃化低温保存实验,并考虑了离心次数对细胞存活率的影响.实验结果表明:玻璃化溶液的组成、浓度及复温后的离心次数等因素对细胞的存活率均有明显的影响.在实验条件下,采用组分配比为5.4 mol/LEG 1.4 mol/L DMSO的玻璃化溶液对成纤维细胞进行玻璃化保存,复温后以1000r/min的转速离心1次(5 min)后,再以800r/min的转速离心4次(每次4 min),可获得较高的细胞存活率,其值为87.1%.     

最小体积法玻璃化保存的研究进展

在低温保存领域,玻璃化能有效防止冰晶的形成,具有良好的保存效果。玻璃化保存需要的条件是极快的降温速率和高浓度的低温保护剂,但高浓度低温保护剂会对细胞造成渗透损伤和毒性损伤。最小体积法能通过减小样本体积,大大提高降温速率,降低实现玻璃化所需的保护剂浓度。本文综述了最小体积法玻璃化保存的最新研究进展,包括有载体的微滴玻璃化保存、喷射微滴玻璃化保存、生物打印微滴玻璃化保存和微流体封装微滴玻璃化保存。其中,喷射微滴玻璃化保存、生物打印微滴玻璃化保存及微流体封装微滴玻璃化保存,是将新型的微滴产生技术与玻璃化技术相结合,因其能迅速产生大小均匀的微滴,具有高通量特点,在低温保存领域具有很大的发展潜力。     

深低温冻存血对细胞形态学及六项细胞化学影响的观察

血细胞经液氮-196℃冻存,使细胞新陈代谢停止,可以长期保存。我们在工作中见到准备冷冻作骨髓移植的骨髓血中的有核细胞,大多数是外周血的白细胞。本文旨在了解在深低温冻存后白细胞的生化及形态学的变化,拟为临床提供一点参考。     

震荡热管应用于玻璃化保存中的数值模拟

介绍了震荡热管应用于玻璃化保存的新方案,建立了生物组织在玻璃化保存过程中的数学模型,通过ANSYS分析软件,对样品在降温过程中的温度场进行了计算分析和数值模拟.得出了生物组织的瞬时温度分布,并通过模拟结果,计算出了生物组织在降温过程中的降温速率可达2×10~4 ℃/s.研究结果表明:极快速的降温速率可使细胞或组织快速通过0 ℃--60 ℃的危险温度区域,从而抑制冰晶的生成和长大, 减轻胞内冰造成的细胞损伤.     

水产品玻璃化转变温度测定的研究进展

水产品是我国居民食品和出口货物的重要组成部分，水产品部分玻璃化温度的测量有助于冷冻和冷藏方案的设计。本文根据国外在水产品部分玻璃化温度测定方面的实验进展情况，分析了转变温度测定中的一些关健技术，重点在样品制备、实验方法和测量结果等方面。     

玻璃化转变在食品加工保藏中的应用进展及玻璃化转变温度的测定方法

本文从玻璃化转变及玻璃化转变温度的概念出发,阐述了玻璃化转变在食品加工保藏中的两点应用,同时也系统阐述了玻璃化转变温度的测定方法。     

一种新的低温玻璃化破碎技术

提取细胞中的营养成份具有重要意义。基于低温玻璃化保存过程中的低温断裂现象,对目前学和细胞破碎技术进行了综述,在阐明其优缺点的基础上,提出了一种新的细胞破碎方法。通过比较分析,指出了该方法的可行性的和优越性。     

Plasma vitrification and re-use of non-combustible fiber reinforced plastic, gill net and waste glass

Fiber reinforced plastic (FRP) composite material has widespread use in general tank, special chemical tank and body of yacht, etc. The purpose of this study is directed towards the volume reduction of non-combustible FRP by thermal plasma and recycling of vitrified slag with specific procedures. In this study, we have employed three main wastes such as, FRP, gill net and waste glass. The thermal molten process was applied to treat vitrified slag at high temperatures whereas in the post-heat treatment vitrified slags were mixed with specific additive and ground into powder form and then heat treated at high temperatures. With a two-stage heat treatment, the treated sample was generated into four crystalline phases, cristobalite, albite, anorthite and wollastonite. Fine and relatively high dense structures with desirable properties were obtained for samples treated by the two-stage heating treatment. Good physical and mechanical properties were achieved after heat treatment, and this study reveals that our results could be comparable with the commercial products.     

牙鲆胚胎玻璃化冷冻技术研究

对名优经济鱼类牙鲆(Paralichthys olivaceus)胚胎的玻璃化冷冻技术方法进行了研究。筛选出了适合于牙鲆胚胎平衡和培养的基础液BS2,对牙鲆不同时期胚胎在玻璃化液VS2中的耐受能力进行了研究,随着平衡时间的延长,胚胎成活率逐渐降低,4-5对肌节期、16-20对肌节期、尾芽期表现出对玻璃化液较强的适应能力。对洗脱液的种类和浓度进行了筛选,结果显示0．125mol／L．蔗糖洗脱成活率最高。在室温(21～22％)和6℃下分别对牙鲆不同时期胚胎在VS1中的成活率进行了比较研究,结果显示出15—20对肌节期在室温下的成活率高于低温,其它时期胚胎低温下的成活率高于室温。利用VS4、VS2、VS3分别对牙鲆尾芽期、肌效应期、出膜前期胚胎进行玻璃化冷冻保存,取得了5粒成活胚,4粒孵化出膜,成活时间为14～67h。     

细胞组织低温保存中污染和微断裂的防止

本文论述了低温保存的几种基本方法和技术;分析了细胞和组织在降温和复温过程中可能被微生物、细菌、病毒等污染的各种途径,以及组织中产生微裂纹的原因;给出了解决这些问题的办法和相应的措施,以确保经低温保存的细胞和组织能安全地用于医学临床。     

强激光作用下生物组织热损伤问题的研究

详细阐述了强激光对生物组织的影响以及热损伤原理 .讨论了如何建立合理的生物组织热损伤换热模型 ,并根据数值模拟解与热损伤实验数据的比较 ,再进行模型识别 .理论与实验相结合的方法去解决热损伤问题     

羟基磷灰石/钛合金骨替代材料体外培养成骨细胞的实验研究

实验选用小鼠头盖骨成骨细胞,采用体外细胞培养技术对具有羟基磷灰石涂层的钛合金(HA/Ti)与未经过表面改性的钛合金两种骨替代材料进行细胞相容性评价,动态观察两种骨替代材料对成骨细胞生长、附着的影响。结果表明两种骨替代材料对成骨细胞生长无抑制作用,未发生细胞毒性反应,细胞在两种材料表面均能正常粘附、生长、增殖,均具有良好的细胞附着形态和细胞增殖率,而HA/钛合金材料具有更好的成骨性,是一种骨细胞相容性良好的骨替代材料。     

Review on development of electrolytes for dye-sensitized solar cells

Since the prototype of a dye-sensitized solar cell(DSSC)was reported in 1991 by M. Gratzel,it has aroused intensive interest over the past decade due to its low cost and simple preparation procedure.The typical cell consists of a dye-coated mesoporous nanocrystalline TiO_2 film sandwiched between two transparent electroldes.A liquid electrolyte,traditionally containing the trioidide/iodide redox couple,fills the pores of the mesoporous nanocrystalline TiO_2 film and contacts the nanoparticles.Photoexcite...     

A variational framework for fiber‐reinforced viscoelastic soft tissues including damage

Fibrous soft biological tissues such as skin, ligaments, tendons, and arteries are non‐homogeneous composite materials composed of fibers embedded in a ground substance. Cyclic tensile tests on these type of materials usually show a hysteretic stress–strain behavior in which strain rate dependence (viscoelasticity) and softening (Mullins' effect) play a coupled role. The main contribution of the present paper is to present unified variational approach to model both coupled phenomena: nonlinear viscoelasticity and Mullins‐like softening behavior. The approach is labeled as variational because viscous‐strain and damage internal variables are updated based on the minimization of a hyperelastic‐like potential that takes a renewed value at each time step. Numerical examples explores (a) the versatility of the proposed model to account for the two described phenomena according to the chosen functions for the free‐energy and dissipative potentials, (b) the ability of the time‐integration scheme embedded in the incremental potential definition to allow for large time increments, and (c) the capability of the model to mimic experimentally obtained stress–strain cyclic curves of soft tissues. The model implementation on standard finite elements is also tested in which symmetric analytic tangent matrices are used as a natural consequence of the variational nature of the proposed approach. Copyright © 2016 John Wiley & Sons, Ltd.     

Classical and all‐floating FETI methods for the simulation of arterial tissues

High‐resolution and anatomically realistic computer models of biological soft tissues play a significant role in the understanding of the function of cardiovascular components in health and disease. However, the computational effort to handle fine grids to resolve the geometries as well as sophisticated tissue models is very challenging. One possibility to derive a strongly scalable parallel solution algorithm is to consider finite element tearing and interconnecting (FETI) methods. In this study, we propose and investigate the application of FETI methods to simulate the elastic behavior of biological soft tissues. As one particular example, we choose the artery which is—as most other biological tissues—characterized by anisotropic and nonlinear material properties. We compare two specific approaches of FETI methods, classical and all‐floating, and investigate the numerical behavior of different preconditioning techniques. In comparison with classical FETI, the all‐floating approach not only has advantages concerning the implementation but also has advantages concerning the convergence of the global iterative solution method. This behavior is illustrated with numerical examples. We present results of linear elastic simulations to show convergence rates, as expected from the theory, and results from the more sophisticated nonlinear case where we apply a well‐known anisotropic model to the realistic geometry of an artery. Although the FETI methods have a great applicability on artery simulations, we will also discuss some limitations concerning the dependence on material parameters. Copyright © 2014 John Wiley & Sons, Ltd.