How Does Negative Life Change Following Disaster Response Impact Distress Among Red Cross Responders?

The American Red Cross is the largest nongovernmental organization responding to disasters in the United States. This study investigated the impact of negative life change occurring in the year following the September 11, 2001, terrorist attacks on levels of distress among 757 Red Cross Disaster Services Human Resources (national disaster team) employees and volunteers who responded to this disaster. Negative life change in the year following disaster response fully mediated the relationship between disaster response and symptoms of depression and partially mediated the responses between disaster response and posttraumatic stress and anxiety symptoms. Results highlight the importance of life experiences in the year following disaster response and, therefore, the education and follow-up services provided to disaster workers prior to and following disaster assignment. Suggestions for monitoring disaster-related stress during and following assignment are provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Slip in Vibrating Wire Experiments on 3He-4He Mixtures

No Heading We present vibrating wire viscometer experiments in concentrated and dilute ³He-⁴He mixtures showing that the slip length may become orders of magnitude larger than the mean free path due to increased specular scattering of the ³He quasiparticles with the superfluid ⁴He film on the wire. The experimental results are in good agreement with a recent theory for slip which accounts for the cylindrical geometry of the wire and for velocity slip in directions normal as well as tangential to the surface of the wire.PACS numbers: 67.60.Fp, 51.20.+d     

Using DAG Transformations to Verify Euler/Venn Homogeneous and Euler/Venn FOL Heterogeneous Rules of Inference

In this paper we will present a graph-transformation based method for the verification of heterogeneous first order logic (FOL) and Euler/Venn proofs. It has been shown that a special collection of directed acyclic graphs (DAGs) can be used interchangeably with Euler/Venn diagrams in reasoning processes [4]. Thus, proofs which include Euler/Venn diagrams can be thought of as proofs with DAGs where steps involving only Euler/Venn diagrams can be treated as particular DAG transformations. In the work reported here, we will show how the characterization of these manipulations can be used to verify Euler/Venn proofs. Also, a method for verifying the use of heterogeneous Euler/Venn and FOL reasoning rules will be presented that is also based upon DAG transformations.     

Phototoxicity and fluorotoxicity combine to alter the behavior of neutrophils in fluorescence microscopy based flow adhesion assays

The use of fluorescent probes that allow visualization of leukocyte-endothelial cell (EC) interactions has greatly informed our understanding of leukocyte recruitment. However, effects of these agents on the biological functions of leukocytes are poorly described, leading to concerns about the interpretation of such data. Here we used two flow-based neutrophil adhesion assays to compare the effects of phase contrast illumination (PCI) with high intensity illumination (HII) used for fluorescent microscopy, in the presence or absence of five commonly used fluorochromes. Isolated neutrophils were either (1) perfused across P-selectin to establish a population of rolling cells, which were subsequently activated with fMLP; or (2) perfused across EC activated with TNF-alpha. In the absence of fluorescent dyes, HII did not affect levels of leukocyte adhesion; however, subsequent neutrophil behavior was dramatically altered when compared with cells under PCI, for example, dramatically reducing their migration velocities. In the presence of fluorescent dyes, the effects of HII were exacerbated, although the precise nature of the biological effects of these probes was agent specific. Thus, for the first time, our experiments describe the effects of fluorescent microscopy on the separate stages of the neutrophil recruitment process and reveal a previously unsuspected effect of HII on neutrophil migration.     

Cryo-X-ray analysis-A novel tool to better understand the physicochemical reactions at the bioglass/biological fluid interface

The present study deals with the short-term physicochemical reactions at the interface between bioactive glass particles [55SiO(2)-20CaO-9P(2)O(5)-12Na(2)O-4MgO. mol%] and biological fluid (Dulbecco Modified Eagle's Medium (DMEM)). The physicochemical reactions within the interface are characterized by scanning transmission electron microscopy (TEM) (STEM) associated with Energy-dispersive X-ray spectroscopy (EDXS). Microanalysis of diffusible ions such as sodium, potassium, or oxygen requires a special care. In the present investigation the cryo-technique was adopted as a suitable tool for the specimen preparation and characterization. Cryosectioning is essential for preserving the native distribution of ions so that meaningful information about the local concentrations can be obtained by elemental microanalysis. The bioglass particles immersed in biological fluid for 24 h revealed five reaction stages: (i) dealkalization of the surface by cationic exchange (Na(+), Ca(2+) with H(+) or H(3)O(+)); (ii) loss of soluble silica in the form of Si(OH)(4) to the solution resulting from the breakdown of Si--O--Si bonds (iii); repolymerization of Si(OH)(4) leading to condensation of SiO(2)); (iv) migration of Ca(2+) and PO(4) (3-) to the surface through the SiO(2)-rich layer to form CaO-P(2)O(5) film; (v) crystallization of the amorphous CaO-P(2)O(5) by incorporating OH-- or CO(3) (2-) anions with the formation of three different surface layers on the bioactive glass periphery. The thickness of each layer is approximately 300 nm and from the inner part to the periphery they consist of Si--OH, which permits the diffusion of Ca(2+) and PO(4) (3-) ions and the formation of the middle Ca--P layer, and finally the outer layer composed of Na--O, which acts as an ion exchange layer between Na(+) ions and H(+) or H(3)O(+) from the solution.     

夹杂物问题应力场的数值计算

等效夹杂物方法是细观力学中的一种重要方法，文中编制的数值计算程序能在考虑多个夹杂物相互响应的情况下计算材料应力、应变场，并实现了计算结果的三维显示．计算结果与文献中的计算结果非常吻合．本文编制的数值计算程序不仅可以用于研究复合材料的损伤演化及失效，而且利用特殊构型的椭球空洞来模拟裂纹，可以计算裂纹群的应力、应变场。     

优等品硫磺

对于在储运过程中遇到的某些现实情况,广泛采用的"优等品"硫磺标准并非总是适用的.提出对加拿大硫磺开发研究所1977年公布的《成型固体硫磺优等品质量标准》中的一些指标进行修订.建议在加入SLS之前硫磺的水分质量分数为0.8%～1.8%,硫化氢质量分数小于0.003%.     

Antigens and Antibodies of the Antiphospholipid Syndrome as New Allies in the Pathogenesis of COVID-19 Coagulopathy

High prevalence of both criteria and extra-criteria antiphospholipid antibodies (aPL) has been reported in COVID-19 patients. However, the differences in aPL prevalence decreased when an age-matched control group was included. The association of aPL with thrombotic events in COVID-19 is very heterogeneous. This could be influenced by the fact that most of the studies carried out were conducted on small populations enriched with elderly patients in which aPL was measured only at a single point and they were performed with non-standardized assays. The few studies that confirmed aPL in a second measurement showed that aPL levels hardly changed, with the exception of the lupus anticoagulant that commonly reduced. COVID-19 coagulopathy is an aPL-independent phenomenon closely associated with the onset of the disease. Thrombosis occurs later in patients with aPL presence, which is likely an additional prothrombotic factor. B2-glycoprotein deficiency (mainly aPL antigen caused both by low production and consumption) is very common during the SARS-CoV2 infection and has been associated with a greater predisposition to COVID-19 complications. This could be a new prothrombotic mechanism that may be caused by the blockage of its physiological functions, the anticoagulant state being the most important.     

Acute T-Cell-Driven Inflammation Requires the Endoglycosidase Heparanase-1 from Multiple Cell Types

It has been accepted for decades that T lymphocytes and metastasising tumour cells traverse basement membranes (BM) by deploying a battery of degradative enzymes, particularly proteases. However, since many redundant proteases can solubilise BM it has been difficult to prove that proteases aid cell migration, particularly in vivo. Recent studies also suggest that other mechanisms allow BM passage of cells. To resolve this issue we exploited heparanase-1 (HPSE-1), the only endoglycosidase in mammals that digests heparan sulfate (HS), a major constituent of BM. Initially we examined the effect of HPSE-1 deficiency on a well-characterised adoptive transfer model of T-cell-mediated inflammation. We found that total elimination of HPSE-1 from this system resulted in a drastic reduction in tissue injury and loss of target HS. Subsequent studies showed that the source of HPSE-1 in the transferred T cells was predominantly activated CD4⁺ T cells. Based on bone marrow chimeras, two cellular sources of HPSE-1 were identified in T cell recipients, one being haematopoiesis dependent and the other radiation resistant. Collectively our findings unequivocally demonstrate that an acute T-cell-initiated inflammatory response is HPSE-1 dependent and is reliant on HPSE-1 from at least three different cell types.     

脉冲偏转放大器的设计与实现

静态偏转光点是确保光点测试的准确性和可靠性的重要方法之一。本文介绍一种高稳定性的脉冲偏转放大器，其特点是分别提供行、帧偏转线圈不同脉宽且可变幅度的驱动电流，使偏转线圈工作于脉冲静态偏转状态。测试实验表明这种脉冲偏转放大器是一种静态偏转光点的十分有效的测量设备。