An FE-analysis of anisotropic creep damage and deformation in the single crystal SRR99 under multiaxial loads

Multidimensional stress–strain and damage analyses of engineering structural components with the help of numerical simulations are of great interest. These can only be done by using adequate material models and suitable numerical methods. Bertram and Olschewski (Computational modelling of anisotropic materials under creep conditions, Math. Modelling Sci. Comp. 5 (1995) 100–109; Anisotropic creep modeling of the single crystal superalloy SRR99, J. Comp. Mater. Sci. 5 (1996) 12–16), proposed a three-dimensional creep model for single crystals. An anisotropic creep damage model for single crystals was also suggested by Qi and Bertram (W. Qi, A. Bertram, Anisotropic creep damage modeling of single crystal superalloys, Tech. Mech. 17 (1997) 313–322; W. Qi, Modellierung der Kriechschadigung einkristalliner Superlegierungen in Hochtemperaturbereich, Ph.D. dissertation, Technical University Berlin, VDI Verlag, Düsseldorf, 1998; W. Qi, A. Bertram, Damage modeling of the single crystal superalloy SRR99 under monotonous creep, Comput. Mater. Sci. 13 (1998) 132–141). The coupled model has been used to predict the creep deformation and the lifetime of the single crystal SRR99 under uniaxial creep loads at 760°C. The purpose of this work is the application of the coupled model to the simulation of multiaxial creep behavior and damage development, and its dependence upon non-proportional loading paths of SRR99 at 760°C.     

Pulmonary thromboembolism

Pulmonary embolism (PE) is a serious complication of chronic obstructive pulmonary disease (COPD). Retrospective studies on patients with COPD treated in the intensive care unit (ICU) were performed to determine: 1) the frequency of PE; 2) the clinical course of PE in cases of COPD in the ICU; and 3) the frequency of PE as a cause of death in the studied group. The frequency of PE was 10.9% in COPD patients. In the group analysed, clinical presentation of PE was characterized by acute severe, life-threatening complications leading to death in 86.7% of cases. PE was the most frequent cause of death (40.6%) in COPD patients in the ICU. The results of treatment of pulmonary embolism in chronic obstructive pulmonary disease are poor and mortality in this group of patients is very high. We believe that improvement of management can be achieved by antithromboembolic prophylaxis, which should be instituted as soon as possible in all patients with chronic obstructive pulmonary disease in the intensive care unit.     

An exploratory model of knowledge flow barriers within healthcare organizations

Healthcare today is mainly knowledge-based and the diffusion of medical knowledge is imperative for proper treatment of patients. Our study of the industry explored barriers to knowledge flow using a Cultural Historical Activity Theory framework. Our work was exploratory and qualitative in nature, and consisted of three phases: in-depth interviews to explore medical knowledge flow barriers resulting in a model; a case study using a survey approach to test and modify the model; and a Delphi study to validate the generalizability of the model.     

时间相关单光子计数记录快速荧光寿命图像

基于时间相关单光子计数(TCSPC)的荧光寿命成像(FLIM)的获取时间取决于成像的图像尺寸、样品寿命的精度及样品计数率.对于高密度荧光团样品,如染色组织或植物细胞,当前可用的样品计数率与TCSPC荧光寿命成像技术最高的计数率接近.该文描述了在高计数率下TCSPC性能,并估计计数损失及堆积效应.结果表明,整个体系的寿命误差比预料的要小.因此,TCSPC FLIM可在获取时间低于1 s的情况下记录寿命图像.为增加FLIM时间序列记录,利用存储交换技术,在采集下一个光子期间读取正在记录的数据,使用两个平行TCSPC模块,可以每秒两幅图像记录荧光寿命时间序列.该技术可应用于活体植物组织叶绿素的瞬态测量.     

On the formation of delusions.

Four principles are identified that account for most delusion formation. The most important of these is transference--transference to the world at large. The second is the defense against pseudohomosexual impulses as described by Freud (and generally misunderstood). The third is the learning within the family of bizarre meanings of concepts which are assumed erroneously to be the meanings other people use. The fourth is the need to have a more or less consistent understanding of one's life and experiences. Therapeutic implications are drawn. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cholelithiasis in hamsters: Effects of cholic acid and calcium on gallstone formation

Dietary cholic acid (0.1%) and/or calcium (2.6% as calcium carbonate) were added to a semipurified diet containing cholesterol and ethynyl estradiol to determine whether the incidence of pigment and/or cholesterol gallstones would be changed. Male golden Syrian hamsters were fed the experimental diets for 96 days (Group 1, control; Group 3, cholic acid plus calcium) or only an average of 60 days (Group 2, 0.1% cholic acid). Animals in Group 2 became ill (weight loss, low food intake, diarrhea) possibly due to cholic acid (or deoxycholic acid) toxicity. Cholesterol gallstones and crystals were absent in all experimental groups. The incidence of pigment gallstones was: control, Group 1, 12/16; 0.1% cholic acid, Group 2, 3/13; and 0.1% cholic acid plus calcium, Group 3, 11/22. Cholic acid with or without calcium produced an elevation of both liver and plasma cholesterol: Group 2, 80.1 mg/g and 501 mg/dl; Group 3, 103.7 mg/g and 475 mg/dl vs Group 1, 65 mg/g and 209 mg/dl, respectively. The lithogenic indices of the bile were lower in Groups 2 and 3 compared to Group 1, controls, 0.45 and 0.58 vs 1.16, respectively. The extent of the portal tract pathology could not be correlated with the presence or absence of pigment gallstones or with the levels of lithocholic acid in the hamster bile. In summary, when semipurified diets were supplemented with ethynyl estradiol and cholic acid, with and without calcium supplementation, no cholesterol gallstones formed and the incidence of pigment gallstones was not altered.     

The effect of radiopacifiers agents on pH,calcium release,radiopacity, and antimicrobial properties of different calcium hydroxide dressings

The aim of this study was to evaluate the antimicrobial activity, pH level, calcium ion release, and radiopacity of calcium hydroxide pastes associated with three radiopacifying agents (iodoform, zinc oxide, and barium sulfate). For the pH and calcium release tests, 45 acrylic teeth were utilized and immersed in ultrapure water. After 24 h, 72 h, and 7 days the solution was analyzed by using a pH meter and an atomic absorption spectrophotometer. Polyethylene tubes filled with the pastes were used to perform the radiopacity test. For the antimicrobial test, 25 dentin specimens were infected intraorally in order to induce the biofilm colonization and treated with the pastes for 7 days. The Live/Dead technique and a confocal microscope were used to obtain the ratio of live cells. Parametric and nonparametric statistical tests were performed to show differences among the groups (P < 0.05). The pH analysis at 7 days showed significant differences (P < 0.05) among the groups. No differences among the pastes were found in the calcium release test on the 7th day (P > 0.05). The calcium hydroxide/iodoform samples had the highest radiopacity and antimicrobial activity against the biofilm‐infected dentin in comparison to the other pastes (P < 0.05). Calcium hydroxide mixed with 17% iodoform and 35% propylene glycol into a paste had the highest pH, calcium ion release, radiopacity, and the greatest antimicrobial action versus similar samples mixed with BaSO4 or ZnO. Microsc. Res. Tech. 78:620–625, 2015. © 2015 Wiley Periodicals, Inc.     

Phenolic acids and related compounds as antioxidants for edible oils

A series of hydroxy aromatic acids, esters and lactones have been evaluated as antioxidants for lard at 120°C at 0·025%, 0·05% and 0·1% concentrations. Most of the compounds studied are direct biochemical precursors of chalcones and these, in turn, of various flavonoids commonly occurring in plant material.Antioxidant efficiency has been shown to be very dependent on the number of phenolic hydroxyl groups in the molecule and also to be promoted by steric hindrance. Cinnamic acids are more effective than corresponding benzoic acids, and phenylacetic and phenylpropionic acids are even more effective. 3,4-Dihydroxy chalcone is more effective than the analogous caffeic acid. In general, the presence of a carbonyl group in the molecule appears to be necessary in this series for a high level of antioxidant activity.     

The effect of interactions on the saturation remanence of particulate assemblies

The effect of interactions on the saturation remanence of assemblies of identical, uniaxially anisotropic, single-domain particles is calculated using a spatial-mean interaction field. The particle easy-axis directions are assumed known and given by a distribution function. The remanence is determined by finding the magnetization orientation functional of the particle easy-axis orientation which minimizes the total assembly energy. Curves of remanence versus interaction strength (assembly packing fraction) are shown for a) randomly oriented assemblies of spherical particles with uniaxial crystalline anisotropy only, b) randomly oriented assemblies of acicular particles with shape anisotropy, and c) oriented assemblies of acicular particles with 6:1 aspect ratio. Disregarding external sample-shape demagnetization effects, this model always yields increased remanences due to interactions. A criterion is given which predicts when external shape effects are capable of dominating the net interaction field to yield a reduction in remanence. The applicability of these results and extensions of the theory are discussed in relation to particle assemblies in magnetic tape and high coercivity CoNiP films.     

Liquid Chromatography–High-Resolution Mass Spectrometry for Quantitative Analysis of Gangliosides

Gangliosides are a large family of glycosphingolipids that are abundant in the brain, and have been shown to affect neuronal plasticity during development, adulthood, and aging. We developed a fast, efficient, and sensitive liquid chromatography–mass spectrometry method to quantify eight different classes of gangliosides (GM₁, GM₂, GM₃, GD₃, GD_1a, GD_1b, GT_1b, GQ_1b) in the brains of 2-day-old and 80-day-old Wistar rats. The gangliosides were extracted from rat brain using a modified Svennerholm and Fredman method. After ganglioside class separation using a hydrophilic high performance liquid chromatography (HPLC) column, the resolving power of the LTQ-Orbitrap™ mass spectrometer was used to extract and sum the major species of each ganglioside class, generating fully resolved extracted ion current peaks for both standards and samples. The flexibility and the specificity of this method are such that it can be applied to the analysis of other ganglioside species/classes not discussed in this paper, provided appropriate standards are available. The method had good repeatability (coefficient of variation 4.8–12.3%) and mean recoveries in the range 92–107%.