心电图仪设计综述

介绍了心电图仪(ECG或EKG)的基本架构及心电信号的电子测量和显示的基本原理,探讨了ECG设备的模拟前端(AFE)及信号通道对心率信号实现数字化的问题,并讨论了各种ECG应用,包括自动体外除颤仪(AED)、病人监护仪和高端诊断型ECG及其所提供的多种功能。     

Freeze-dried strawberry powder improves lipid profile and lipid peroxidation in women with metabolic syndrome: baseline and post intervention effects

Background  

Strawberry flavonoids are potent antioxidants and anti-inflammatory agents that have been shown to reduce cardiovascular disease risk factors in prospective cohort studies. Effects of strawberry supplementation on metabolic risk factors have not been studied in obese populations. We tested the hypothesis that freeze-dried strawberry powder (FSP) will lower fasting lipids and biomarkers of oxidative stress and inflammation at four weeks compared to baseline. We also tested the tolerability and safety of FSP in subjects with metabolic syndrome. FSP is a concentrated source of polyphenolic flavonoids, fiber and phytosterols.     

Managing discrimination in selection: The influence of directives from an authority and social dominance orientation.

The authors examined one manner in which to decrease the negative impact of social dominance orientation (SDO), an individual difference variable that indicates support for the "domination of 'inferior' groups by 'superior' groups" (J. Sidanius & F. Pratto, 1999, p. 48), on the selection of candidates from low-status groups within society. Consistent with the tenets of social dominance theory, in 2 studies we found that those high in SDO reported that they were less likely to select a potential team member who is a member of a low-status group (i.e., a White female in Study 1 and a Black male in Study 2) than those low in SDO. However, explicit directives from an authority moderated this effect such that those high in SDO were more likely to select both candidates when authority figures clearly communicated that job performance indicators should be used when choosing team members. Thus, our studies suggest that the negative effects of SDO may be attenuated if those high in SDO are instructed by superiors to use legitimate performance criteria to evaluate job candidates. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The relationship between clients' expected and actual treatment duration.

Investigated the relationship of clients' expected and actual treatment duration in 148 outpatients (mean age 27 yrs) treated by 20 therapists. Data from questionnaires suggest that clients expected and attended a relatively low number of visits; these patterns were discrepant with the therapists' duration preferences. A stepwise regression analysis indicated that clients' expected number of visits was the only variable that incrementally increased the predictability of client visits. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ex vivo culture of peripheral blood CD34+ cells: effects of hematopoietic growth factors on production of neutrophilic precursors

A major potential application for ex vivo culture of hematopoietic progenitor cells is the treatment of cytopenia following high-dose chemotherapy and hematopoietic transplantation. We have previously postulated that infusion of a sufficient number of neutrophil postprogenitor cells generated by ex vivo culture of CD34+ cells may be able to abrogate neutropenia. In this article, we describe further development of an efficient stromal-free, cytokine-dependent, static culture system for generation of these cells. Our previous studies indicated that maximal production of nucleated cells and myeloid progenitor cells from PB CD34+ cells occurred with multiple hematopoietic growth factor (HGF), notably the 6-HGF combination of interleukin (IL)-1, IL-3, IL-6, granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage-CSF (GM-CSF), and stem cell factor (SCF). In the present study, we determine the contribution of each of these 6 HGF in generation of neutrophilic precursors. SCF, G-CSF, and IL-3 were found to be the most important HGF for production of neutrophilic cells. The 4-HGF combination of IL-3, IL-6, G-CSF, and SCF was optimized by performing dose-response experiments and shown to be as potent as 6 HGF for production of nascent CFU-GM and neutrophilic precursors.     

Oral Dosage Development of a Human Rhinovirus and Non-Polio Enterovirus Inhibitor

WIN 63843, a Picornavirus replication inhibitor, is physically and chemically stable in the solid state, to light, elevated temperature, and humidity. This 3-ary15-trifluoromethyl disubstituted 1,2,4-oxadiazole compound has very low water solubility but is highly soluble in ethanol and in safflower seed and corn oils. Solubility in the vegetable oils is doubled by the synergistic effect of ethanol at the 16% alcohol concentration. Vegetuble oil solutions of WIN 63843 are thermally stable but react slowly in the presence of light resulting in an amidoxime compound (WIN 65489) formed by opening of the 1,2,4-oxadiazole ring. This reaction does not occur in oil solutions containing small concentrations of ethanol. Of biophannaceutical interest, the addition of ethanol or PEG-400 solutions of WIN 63843 to human gastric fluid resulted in oily droplet formation whereas crystals form upon addition of these solutions to water. Also, the compound is greater than 8,000 times more soluble in human gastric fluid.     

Assessment of Concrete in Sulfate Soils

An investigation of concrete exposed to sulfate soils is used to illustrate a methodology for the systematic study of the condition of concrete in service. Condition surveys of the site and tests of engineering properties of the concrete were supplemented by examination of concrete cores using the stereomicroscope, the optical microscope, the electron microscope, analysis by wet chemistry, thermal analysis, and X-ray diffraction. Step-by-step progression from large scale (tens of meters) to submicroscopic scales (tens of nanometers) gave continuity to detailed test methods. It also allowed for the selection of specimens appropriately representing the concrete as a whole, and ensured reliable interpretation of the results. In many cases, more than one test method provided the same or similar information. The writers believe the methodology employed will be of value to other investigators.