Consistency of maternal behavior from infancy to preadolescence.

Continuing studies on the effect of the mother on child development, the present investigation establishes that (a) interviews with the mother elicit comparable data to that gleaned from direct observation of the mother-child interaction and (b) at least with regard to the love-hate dimension, there is a consistent pattern of relationship between mother and child during infancy and in to preadolescence. Such validation was not found with regard to the factor of the autonomy-control continuum. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quantitative analysis of the cross-linked structure of microgels using fluorescent probes

Properties of polymeric microgels are influenced by the internal polymer cross-linked structure, but tools to quantitatively analyze this internal structure are limited. With the finding that polymer networks alter the diffusivity and subsequent excimer formation of pyrene, this study used the ratio between pyrene excimer and monomer emission to determine the number of cross-links (N) and average pore size (ξ) in poly(ethylene glycol) diacrylate (PEGDA) microgels. A calibration curve to relate pyrene emission to N and ξ in PEGDA hydrogels was prepared and used to calculate N and ξ in PEGDA microgels. The pyrene emission indicated that PEGDA microgels had a higher cross-linking density and a smaller average pore size when compared with bulk cross-linked hydrogels of the same PEGDA concentration. The analytical method demonstrated in this study may be useful for fine-tuning polymeric microgel properties for a broad array of applications.     

用于粉磨水泥熟料和高炉矿渣的莱歇磨

莱歇磨常用于水泥工业粉磨原料、水泥窑用煤粉生产、炼铁厂以及发电厂.从上世纪90年代初期开始,莱歇公司(Loesche)陆续研发了粉磨水泥熟料和高炉矿渣的2+2、3+3技术.截止2008年底,莱歇已售出各种规格的水泥立磨200台.台时产量达330t的LM63+3已在印度投产,各项指标均达到设计指标.用一台这样的立磨可以满足5 000t/d生产线配套.实现"一窑一磨"的生产线配套.多年来莱歇公司在研发、设计、制造、安装、调试方面积累了许多经验,证明立磨粉磨水泥、矿渣是完全可行的.以下是莱歇磨投入使用的历程回顾.     

纳米压印光刻技术--下一代批量生产的光刻技术

纳米压印光刻技术已被证实是纳米尺寸大面积结构复制的最有前途的下一代技术之一。这种速度快、成本低的方法成为生物化学、μ级流化学、μ-TAS和通信器件制造以及纳米尺寸范围内广泛应用的一种日渐重要的方法,如生物医学、纳米流体学、纳米光学应用、数据存储等领域。由于标准光刻系统的波长限制、巨大的开发工作量、以及高昂的工艺和设备成本,纳米压印光刻技术可能成为主流IC产业中一种真正富有竞争性方法。对细小到亚10nm范围内的极小复制结构,纳米压印技术没有物理极限。从几种纳米压印光刻技术中选择两种前景广阔的方法——热压印光刻(HEL)和紫外压印光刻(UV-NIL)技术给予介绍。两种技术对各种各样的材料以及全部作图的衬底大批量生产提供了快速印制。重点介绍了HEL和UV-NIL两种技术的结果。全片压印尺寸达200mm直径,图形分辨力高,拓展到纳米尺寸范围。     

Impact of the chain extension of poly(ethylene terephthalate) with 1,3‐phenylene‐bis‐oxazoline and N,N′‐carbonylbiscaprolactam by reactive extrusion on its properties

In this article, the material properties of chain extended poly(ethylene terephthalate) (PET) by application of the chain extenders, 1,3‐phenylene‐bis‐oxazoline (1,3‐PBO), N,N′‐carbonylbiscaprolactam (CBC), and combinations thereof are investigated aiming at an application during fiber production from postconsumer PET. The chain extension is performed in one step by a reactive extrusion process. The chain extenders are linearly linked to the COOH and/or OH terminal groups of PET. The influence of the chain extension on the properties of PET is analyzed by measurement of the inherent viscosity, size exclusion chromatography, and carboxyl end‐group titration. Furthermore, the impact of the chain extension on the thermal and rheological properties of PET is studied in detail by differential scanning calorimetry and rheology. The results demonstrate that chain extenders have impact on the properties of PET in dependence on their chemical composition and concentration. The improvement of the molecular weight of the obtained compounds is achieved in an effective and economical approach by the addition of small concentrations of chain extenders (0.2 wt% 1,3‐PBO or 0.3 wt% CBC) without significant negative impact on the properties of PET. POLYM. ENG. SCI., 59:284–294, 2019. © 2018 Society of Plastics Engineers     

An Experimental Workflow for Studying Barrier Integrity,Permeability, and Tight Junction Composition and Localization in a Single Endothelial Cell Monolayer: Proof of Concept

Endothelial and epithelial barrier function is crucial for the maintenance of physiological processes. The barrier paracellular permeability depends on the composition and spatial distribution of the cell-to-cell tight junctions (TJ). Here, we provide an experimental workflow that yields several layers of physiological data in the setting of a single endothelial cell monolayer. Human umbilical vein endothelial cells were grown on Transwell filters. Transendothelial electrical resistance (TER) and 10 kDa FITC dextran flux were measured using Alanyl-Glutamine (AlaGln) as a paracellular barrier modulator. Single monolayers were immunolabelled for Zonula Occludens-1 (ZO-1) and Claudin-5 (CLDN5) and used for automated immunofluorescence imaging. Finally, the same monolayers were used for single molecule localization microscopy (SMLM) of ZO-1 and CLDN5 at the nanoscale for spatial clustering analysis. The TER increased and the paracellular dextran flux decreased after the application of AlaGln and these functional changes of the monolayer were mediated by an increase in the ZO-1 and CLDN5 abundance in the cell–cell interface. At the nanoscale level, the functional and protein abundance data were accompanied by non-random increased clustering of CLDN5. Our experimental workflow provides multiple data from a single monolayer and has wide applicability in the setting of paracellular studies in endothelia and epithelia.     

Engraftment of Prevascularized,Tissue Engineered Constructs in a Novel Rabbit Segmental Bone Defect Model

The gold standard treatment of large segmental bone defects is autologous bone transfer, which suffers from low availability and additional morbidity. Tissue engineered bone able to engraft orthotopically and a suitable animal model for pre-clinical testing are direly needed. This study aimed to evaluate engraftment of tissue-engineered bone with different prevascularization strategies in a novel segmental defect model in the rabbit humerus. Decellularized bone matrix (Tutobone) seeded with bone marrow mesenchymal stromal cells was used directly orthotopically or combined with a vessel and inserted immediately (1-step) or only after six weeks of subcutaneous “incubation” (2-step). After 12 weeks, histological and radiological assessment was performed. Variable callus formation was observed. No bone formation or remodeling of the graft through TRAP positive osteoclasts could be detected. Instead, a variable amount of necrotic tissue formed. Although necrotic area correlated significantly with amount of vessels and the 2-step strategy had significantly more vessels than the 1-step strategy, no significant reduction of necrotic area was found. In conclusion, the animal model developed here represents a highly challenging situation, for which a suitable engineered bone graft with better prevascularization, better resorbability and higher osteogenicity has yet to be developed.     

Addressing amorphization and transgranular fracture of B4C through Si doping and TiB2 microparticle reinforcing

Over the last two decades, many studies have contributed to improving our understanding of the brittle failure mechanisms of boron carbide and provided a road map for inhibiting the underlying mechanisms and improving the mechanical response of boron carbide. This paper provides a review of the design and processing approaches utilized to address the amorphization and transgranular fracture of boron carbide, which are mainly based on what we have found through 9 years of work in the field of boron carbides as armor ceramics.     

Friction and adhesion in boundary lubrication measured by microtribometers

The measuring and modelling of friction are critically important for the motion control in nanopositioning, particularly when bearings are employed to cover the wide working distances. Since the positioning system usually operates at very low speed to achieve fine positioning, the boundary lubrication is the dominant regime. A detailed characterization of the friction of boundary lubrication formed by Poly–α–Olefin (PAO) with and without surfactant and a suspension of MoS₂ in base oil has been performed in reciprocating sliding tests by steel/steel point contacts, and correlated with adhesion measurements by silicon/silicon point contacts. A microtribometer based on laser interferometers and glass springs, which can resolve 100 nN force in a speed range of 1–1000 μm/s was employed to detect the minute changes in forces. We find that a simple linear function instead of a logarithmic function is possible to describe the relationship between the friction force and operating speed for all the lubricants tested, though the gradients are quite different and under the influence of normal load. Comparing to PAO+surfactant and MoS₂ suspension, PAO shows a much higher load-dependent coefficient of friction. This result is further confirmed by the repulsion force measurements, which shows a higher increase of contact pressure with the increase of normal load for PAO.