Bonding mechanism and stress distribution of a glass frit free thick film metallization for AlN-ceramic

Typical thick film pastes applied for the metallization of AlN-ceramics are glass bonding systems. The glass phase responsible for adhesion onto the ceramic unfortunately also acts as a heat barrier and impairs the excellent thermal conductivity of AlN. A new glass frit free conductor paste has been especially developed for the metallization of AlN. A numerical analysis of the stress distribution within the metallized ceramic induced by a continuous as well as a pulsed mode operating heat source has been conducted for this new metallization paste and, for comparison purpose, also for a standard thick film paste by means of a finite element program. In order to determine the physical property data of the phases occurring at the interface between metallization and substrate required for numerical simulation the relevant intermetallic samples have been synthesized.     

Evaluation of biocompatibility of the copolymer of 2-hydroxyethyl methacrylate with 2-(methylsulfanyl)ethyl methacrylate

This study compares subcutaneous and intracerebral biocompatibilty of two hydrogels: copolymer of 2-hydroxyethyl methacrylate with 2-(methylsulfanyl)ethyl methacrylate and poly(2-hydroxyethyl methacrylate) as reference polymer. The experimental copolymer was more biologically inert than poly(2-hydroxyethyl methacrylate) in both the studied parameters, hence the former material is a suitable candidate for biomedical application.     

Effect of cationic groups on the adhesivity of peritoneal macrophages to polymeric beads

This study demonstrates the adhesion of macrophages to polymer beads from a copolymer of hydroxyethyl methacrylate and dimethyl aminoethyl methacrylate intraperitoneally injected into the rat. Dimethyl aminoethyl methacrylate exhibited a stimulatory effect on macrophage adhesion 5 h after injection of the beads. Electron microscopy demonstrated protein adsorption on the surface of the beads. Protein fibres between the cell surface and beads were observed. The experimental system used minimizes the influence of tissue damage at macrophage recognition of polymers. This method seems to be suitable for short-term investigation of macrophage-polymer interaction.     

Brain lesion-induced alteration of selected phenotypic properties of spleen macrophages and their partial restoration in the course of foreign body reaction against intraperitoneally implanted polymers

A lesion in the dorsoposterior part of the rat brain septum is known to exert an inhibitory effect on the delayed skin hypersensitivity and incorporation of radiolabeled thymidine into the lymphoid organs. To determine whether distinct properties of macrophages will also be modulated by this type of injury, we have focused upon the monitoring of expression of sugar receptors (lectins). In this study we show a reduction in the number of macrophages expressing carbohydrate-binding sites for asialoglycoproteins (-D-galactoside), -D-mannoside and -D-mannoside-6-phosphate in spleen macrophages after the lesion of the dorsoposterior septum of the brain in the rat. The number of ED-1⁺ macrophages was not influenced. The intraperitoneal injection of beads prepared from the copolymer of 2-hydroxyethyl methacrylate with dimethyl aminoethyl methacrylate (30 wt %) elevated significantly the number of ED-1⁺ spleen macrophages and number of macrophages with binding site(s) recognizing asialoglycoproteins and -D-mannoside-6-phosphate, respectively. These results indicate that a foreign-body reaction appears to be able to mediate a phenotypic restoration of lectin expression by spleen macrophages altered by the brain lesion. It can be suggested that, for example, a probable production of cytokines by the inflammatory cells colonizing the implanted beads plays a role in this process. © 1999 Kluwer Academic Publishers     

Influence of vermiculite on the formation of porous cordierites

Porous cordierites were prepared from mixtures of talc, kaolinite and vermiculite with alumina or aluminum hydroxide by sintering in an argon atmosphere at 1300 °C for 1 h (porous cordierites of Group I) and 2 h (porous cordierites of Group II). Group I and Group II were different in pore size distribution, quantitative content of mineral phases and cordierite structure parameters. The crystalline phases identified in porous cordierites prepared without vermiculite were cordierite (69–88 vol.%), protoenstatite (25–13 vol.%) and corundum (3–10 vol.%). Vermiculite increased the content of cordierite (84–90 vol.%) and Mg–Al spinel (4–15 vol.%) at the expense of protoenstatite. The calculated unit cell parameters of cordierites were between those of orthogonal and hexagonal cordierites (Group I) and corresponded to disordered orthorhombic rather than hexagonal cordierites (Group II). Group I cordierites had pore size maxima at about ~ 35 µm or ~ 20 µm, while Group II had maxima at about 35 µm, 25 µm and 18 µm. Porous cordierites prepared from alumina admixture had slightly lower pore volumes than those prepared from gibbsite. Cordierites prepared from mixtures rich in vermiculite and gibbsite showed the highest porosity (63% and 57%).     

Synthetic Polyamine BPA‐C8 Inhibits TGF‐β1‐Mediated Conversion of Human Dermal Fibroblast to Myofibroblasts and Establishment of Galectin‐1‐Rich Extracellular Matrix in Vitro

Cancer‐associated fibroblasts (CAFs) play a role in the progression of malignant tumors. They are formed by conversion of fibroblasts to smooth muscle α‐actin‐positive (SMA‐positive) myofibroblasts. Polyamines are known to change the arrangement of the actin cytoskeleton by binding to the anionic actin. We tested the effect of the synthetic polyamine BPA‐C8 on the transition of human dermal fibroblasts to myofibroblasts induced either by TGF‐β1 alone or by TGF‐β1 together with adhesion/growth‐regulatory galectin‐1. Pre‐existing CAFs, myofibroblasts from pancreatitis, and rat smooth muscle cells were also exposed to BPA‐C8. BPA‐C8 impaired myofibroblast formation from activated fibroblasts, but it had no effect on cells already expressing SMA. BPA‐C8 also reduced the occurrence of an extracellular matrix around the activated fibroblasts. The reported data thus extend current insights into polyamine activity, adding interference with tumor progression to the tumor‐promoting processes warranting study.     

减少锡须

组建iNEMI锡须用户研究小组的目的就是为了把锡须引起的故障风险减至最小程度。本文回顾了该小组的推荐意见，它反映了现在可以获得的有关锡须形成和控制的最新资料．包括常用的无铅处理涂层的信息及其帮助减少锡须的效果。[编者按]     

To the incidence of nucleoli in circulating myeloblasts of patients suffering from acute myeloblastic, promyelocytic and myelomonocytic leukemias

This retrospective clinical study describes three years of experience with cryoprotected-cryopreserved allograft transplantation. During this period 33 knee joints were operated on for different reasons including osteoarthritis, osteochondritis dissecans and post-traumatic surface irregularity. The mean follow-up was nearly two years and the mean age of the patients was 48 years. The grafts were harvested and processed at the West Hungarian Tissue Bank according to the criteria promulgated by the European Association of Tissue Banks. All the operations were performed in the same way. Three types of grafts were used: cylindrical or mushroom-shaped for the femoral condyle and patellar and shell allografts for resurfacing the tibial plateau. Bone matrix gelatine (BMG) and fibrin sealant (Tissucol) were used locally to enhance the revascularisation and to improve the decreased osteoinductivity of the frozen cancellous bone. According to the modified Bentley score, the success rate of the short term follow-up was similar to that of other reported series. An analysis of four biopsies showed that the BMG and fibrin sealant did not appear to affect the viability of the articular cartilage. We conclude that application of these materials is not contra-indicated in allograft surgery.     

Adolescent–parent interactions in middle-class African American families: Longitudinal change and contextual variations.

Family interactions were examined longitudinally over 2 years in 79 middle-class African American families with early adolescents. Mothers and adolescents (as well as fathers and adolescents and triads in 2-parent families) were videotaped discussing a conflict for 10 min. A macro-coding system (J. G. Smetana, J. Yau, A. Restrepo, & J. L. Braeges, 1991) was modified to be culturally sensitive to African American families. Interaction ratings were reduced, through principal-components analyses, into composite variables. After control for family income, mothers' communication in triadic interactions became less positive over time. Both mothers' and fathers' communication was more positive in dyadic than triadic interactions. In triadic interactions, mothers validated sons more than daughters, and in dyadic interactions with either parent, boys were more receptive to parents than were girls. Findings extend previous research on adolescent–parent relationships to African American families. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preschool children's conceptions of transgressions: Effects of varying moral and conventional domain-related attributes.

57 38–76 mo old Ss enrolled in preschool and/or day care centers were assigned to either 6 story-stimulus conditions or to a word-evaluation condition. Ss in the 6 story-stimulus conditions either heard stories describing familiar moral or conventional transgressions or stories varying in the consistency of prohibitions regarding actions and responses to events. Some events were unspecified. Ss were asked to justify the events' wrongness and make a series of judgments on criteria previously found to be associated with the domains. Ss' judgments and justifications were reassessed 1 wk later. Results show that Ss differentiated between familiar moral and social-conventional transgressions and that they treated stories having attributes associated with each domain like prototypical moral or conventional transgressions. The presence or absence of information regarding event-unspecified consequences of actions differentiated criterion judgments. Responses to the word-evaluation condition (in which Ss' judgments were assessed in the absence of stories) revealed no response biases to the questions. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)