Interactions between early parenting and a polymorphism of the child's dopamine transporter gene in predicting future child conduct disorder symptoms.

Mounting evidence suggests that genetic risks for mental disorders often interact with the social environment, but most studies still ignore environmental moderation of genetic influences. The authors tested interactions between maternal parenting and the variable number tandem repeat (VNTR) polymorphism in the 3′ untranslated region of the dopamine transporter gene in the child to increase understanding of gene–environment interactions involving early parenting. Participants were part of a 9-year longitudinal study of 4- to 6-year-old children who met criteria for attention-deficit/hyperactivity disorder (ADHD) and demographically matched controls. Maternal parenting was observed during standard mother–child interactions in Wave 1. The child's conduct disorder (CD) symptoms 5–8 years later were measured using separate structured diagnostic interviews of the mother and youth. Controlling for ADHD symptoms and child disruptive behavior during the mother–child interaction, there was a significant inverse relation between levels of both positive and negative parenting at 4–6 years and the number of later CD symptoms, but primarily among children with 2 copies of the 9-repeat allele of the VNTR. The significant interaction with negative parenting was replicated in parent and youth reports of CD symptoms separately. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analysis of the diametral compression method for determining the tensile strength of transparent magnesium aluminate spinel

Attempts were made to determine the inherent tensile strength of a coarse-grained, hot-pressed magnesium aluminate spinel (MgAl₂O₄) using the diametral compression test. Thick (9.6 mm) disk specimens were machined from a large (356 mm square) plate of spinel. Two pairs of tungsten carbide (WC) platens, one with flat surfaces and the other with a 20° half-arc and radius matched to the disk diameter, were used to transfer the applied load. Specimens tested using the platens with the matched radius had strength values almost 50% higher than those tested using flat platens. Images of the fracture process captured using a high-speed camera showed that irrespective of the type of platens used, fracture consistently initiated at the loading interface, resulting in an invalid test. These results show that the diametral compression test method is not appropriate for determining the tensile strength of this spinel and it raises concerns about the applicability of the method for any advanced ceramic.     

全光纤光学相干层析牙齿检测系统的解调

结合虚拟仪器技术和光学相干层析技术,设计了用于口腔牙齿检测的全光纤光学相干层析系统.通过对干涉信号进行一系列的变换、分析,获得离体牙齿的二维图像.使用LabVIEW实现信号的解调及控制,包括步进电机的驱动、数据同步采集控制、数字滤波、提取信号包络以及二维图像的重建.通过实验可测量出离体牙齿的内部细微结构,为早期的龋齿诊断提供依据.     

Kinetics and thermal crystallinity of recycled PET. II. Topographic study on thermal crystallinity of the injection-molded recycled PET

The injected specimens of recycled poly(ethylene terephthalate) (R-PET) and its blends with engineering PET (E-PET) are studied with differential scanning calorimetry (DSC). Specimens are dissected into three segments of (1) outer skin, (2) middle, and (3) the core for the topographic study of their separate crystallinities, which are induced by different crystallization rates in the injection mode. DSC thermograms reveal the different crystallinity states among these three segments with decreasing crystallinity from core to middle to the skin segments and the times and contact of injection-molded specimens with the mold during the cooling cycle after the injection of the specimens. With the same procedures of injection molding, comparisons of crystallinity among various specimens of virgin blow molding grade PET (B-PET), E-PET, and R-PET are made. There are little differences in crystallinity among three segments of B- or E-PET specimens. In contrast, a higher degree of crystallinity in the core segment than either middle or skin segments is observed for the R-PET. This may contribute to the faster crystallization rate of the R-PET in the mold. Specimens of R-/E-PET blends follow the R-PET pattern, even in 20% of R-PET in the blend. This faster crystallization rate of R-PET is confirmed with the lowering crystallization temperatures (T_c) of the R-PET and R-/E-PET blended specimens in the DSC heating process. Dynamic DSC cooling analysis reveals a high order of crystallinity in R-PET and R-/E-PET blends. Gel permeation chromatography (GPC) measurements of molecular weights and distributions support the orderly structure for R-PET. Terminal group analysis and intrinsic viscosity measurements of the R-PET support the chain modification of R-PET during the thermal treatments in accordance with the evidences of smaller M_w and narrower molecular-weight distribution from the GPC findings for the recycled PET. © 1996 John Wiley & Sons, Inc.     

智能手机如何实现数据同步化

手机的使用模式相当简单:用户端口只要离PC数尺的距离,蓝牙手机就能自动进行电子邮件、相片、工作清单、联络人等数据的同步化.但有时用户对蓝牙的同步化与数据传输功能仍存在一些困惑,如PC虽然有蓝牙功能,但却经常无法连上手机如第一次就想让蓝牙功能顺利执行仍需要一些技巧,并不能立马使用等.本文详细为您讲述如何使智能手机实现数据同步化.     

Role of Tyrosine Kinase Syk in Thrombus Stabilisation at High Shear

Understanding the pathways involved in the formation and stability of the core and shell regions of a platelet-rich arterial thrombus may result in new ways to treat arterial thrombosis. The distinguishing feature between these two regions is the absence of fibrin in the shell which indicates that in vitro flow-based assays over thrombogenic surfaces, in the absence of coagulation, can be used to resemble this region. In this study, we have investigated the contribution of Syk tyrosine kinase in the stability of platelet aggregates (or thrombi) formed on collagen or atherosclerotic plaque homogenate at arterial shear (1000 s⁻¹). We show that post-perfusion of the Syk inhibitor PRT-060318 over preformed thrombi on both surfaces enhances thrombus breakdown and platelet detachment. The resulting loss of thrombus stability led to a reduction in thrombus contractile score which could be detected as early as 3 min after perfusion of the Syk inhibitor. A similar loss of thrombus stability was observed with ticagrelor and indomethacin, inhibitors of platelet adenosine diphosphate (ADP) receptor and thromboxane A₂ (TxA₂), respectively, and in the presence of the Src inhibitor, dasatinib. In contrast, the Btk inhibitor, ibrutinib, causes only a minor decrease in thrombus contractile score. Weak thrombus breakdown is also seen with the blocking GPVI nanobody, Nb21, which indicates, at best, a minor contribution of collagen to the stability of the platelet aggregate. These results show that Syk regulates thrombus stability in the absence of fibrin in human platelets under flow and provide evidence that this involves pathways additional to activation of GPVI by collagen.     

选择同轴电缆和双绞线

因其性能的限制,铜缆的应用几次走到了尽头。之后,新工艺和元件的推出又使它得到了重生。对于两种最常用的高性能铜缆,同轴电缆和双绞线理论上是有局限性的,然而,我们离这些极限有多近呢？