Sample preparation strategies for targeted proteomics via proteotypic peptides in human blood using liquid chromatography tandem mass spectrometry

The simultaneous quantification of protein concentrations via proteotypic peptides in human blood by liquid chromatography coupled to quadrupole MS/MS is an important field of bioanalytical research with a high potential for routine diagnostic applications. This review summarizes currently available sample preparation procedures and trends for absolute protein quantification in blood using LC-MS/MS. It discusses approaches of transferring established qualitative protocols to a quantitative analysis regarding their reliability and reproducibility. Techniques used to enhance method sensitivity such as the depletion of high-abundant proteins or the immunoaffinity enrichment of proteins and peptides are described. Furthermore, workflows for (i) protein denaturation, (ii) disulfide bridge reduction and (iii) thiol alkylation as well as (iv) enzymatic digestion for absolute protein quantification are presented. The main focus is on the tryptic digestion as a bottleneck of protein quantification via proteotypic peptides. Conclusively, requirements for a high-throughput application are discussed.     

Numerical study of light scattering by a boundary-layer flow

Temperature inhomogeneities in free, isotropic turbulence have the effect of scattering light in near-forward angles. We investigate numerically modifications of free turbulence by a rigid wall and its effect on the propagation of light through turbulence. The wall is a 5 cm optical window placed at the leading edge of an instrument towed with speeds of 0.1 and 1 m/s in free turbulence. The turbulent flow field presents inhomogeneities of an embedded passive scalar (Pr = 7, temperature in water), which are modified by the boundary layer developing on the window. We find that the developing laminar boundary layer has a negligible effect on light scattering for the investigated geometry when considered in terms of the volume-scattering function (differential cross section). This indicates that the boundary layer is not an obstacle for optical measurements of turbulence.     

Tolerance Analysis for Design of Multistage Manufacturing Processes Using Number-Theoretical Net Method (NT-net)

Recent developments in modeling stream of variation in multistage manufacturing system along with the urgent need for yield enhancement in the semiconductor industry has led to complex large scale simulation problems in design and performance prediction, thus challenging current Monte Carlo (MC) based simulation techniques. MC method prevails in statistical simulation approaches for multi-dimensional cases with general (i.e., non-Gaussian) distributions and/or complex response functions. A method is proposed based on number theory (NT-net) to reduce computing effort and the variability of MC's results in tolerance design and circuit performance simulation. The sampling strategy is improved by introducing NT-net that can provide better convergent rate over MC. The new method is presented and verified using several case studies, including analytical and industrial cases of a filter design and analyses of a four-bar mechanism. Results indicate a 90–95% reduction of computation effort with significant improvement in accuracy that can be achieved by the proposed technique.     

Light scattering on oceanic turbulence

Turbulent inhomogeneities of fluid flow have the effect of scattering light in near-forward angles, thus providing an opportunity to use optics to quantify turbulence. Here we report measurements of the volume-scattering function in the range of 10(-7) to 10(-3) rad using a wave-front sensing technique. The total scattering coefficient b, due to scattering on turbulent inhomogeneities, is between 1 and 10 m(-1) under typical oceanographic conditions. The numerical calculations of turbulent volume-scattering functions compare well with the laboratory measurement. These results suggest that optical measurements at small angles are affected by turbulence-related scattering, and their effects can be well modeled with numerical calculations.     

应用有限元法(FEM)验证在直齿轮和斜齿轮内采用ISO和AGMA标准的齿根强度的比较分析

在工程界现在普遍的趋势是要求重新研究各不同的标准以确是其在工业内最好的实践.本文介绍采用在ISO和AGMA标准对齿根强度估算方法的比较分析,并用开发的有限元和模型仿真进行证实.本分析(1)介绍了采用齿条和齿轮刀具制造的广大范围的直齿和斜齿轮,而(2)是齿轮主要几何学(齿轮设计),制造(齿条和齿轮刀具)和性能参数的不同组合,以及对每个齿轮进行齿根强度分析的有限元方法(FEM).FEM的结果与用ISO和AGMA标准计算的相比较.对不同的设计、制造和性能参数组合的比较分析用图解说明和简要讨论.该结果将许可在现代工程实际中应用标准所存在的限制有一个很好的了解,并为改进和统一标准提供一个基础.     

Tolerance allocation for compliant beam structure assemblies

This paper presents a tolerance allocation methodology for compliant beam structures in automotive and aerospace assembly processes. The compliant beam structure model of the product does not require detailed knowledge of product geometry and thus can be applied during the early design phase to develop cost-effective product specifications. The proposed method minimizes manufacturing costs associated with tolerances of product functional requirements (key product characteristics, KPCs) under the constraint(s) of satisfying process requirements (key control characteristics, KCCs). Misalignment and fabrication error of compliant parts, two critical causes of product dimensional variation, are discussed and considered in the model. The proposed methodology is developed for stochastic and deterministic interpretations of optimally allocated manufacturing tolerances. An optimization procedure for the proposed tolerance allocation method is developed using projection theory to considerably simplify the solution. The non-linear constraints, that ellipsoid defined by τ(stochastic case) or rectangle defined by T x (deterministic case) lie within the KCC region, are transformed into a set of constraints that are linear in σ(or T x )-coordinates. Experimental results verify the proposed tolerance allocation method.     

Psychologists on psychology: The inquiry beliefs of psychologists by subdiscipline, gender, and age.

Three hundred six psychologists, all members of the American Psychological Association, responded to a questionnaire on which they rated various theoretical-philosophical statements concerning the conduct of psychological inquiry. Results were considered in relation to the subdiscipline of psychology to which respondents belonged, their gender, and their decade of birth. Results for subdiscipline indicated progressively weaker relative support for naturalism, reductionism, empiricism, and experimentalism as the context of subdisciplinary inquiry became increasingly broad. Women were less attached to experimental methods than men and displayed a stronger belief in the importance of political factors in research than did their male counterparts. Finally, younger psychologists believed more strongly in the importance of presentation skills such as good writing and rhetoric with respect to research and academic success. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quality-driven Sequence Planning and Line Configuration Selection for Compliant Structure Assemblies

Assembly sequence planning is an integral part of a new product and process development. However, currently there are very few available approaches to evaluate the impact of assembly sequences on product quality. This paper develops a methodology for Quality-driven Sequence Planning (Q/SP) with consideration to product dimensional quality based on the following three steps: (1) Sequence generation for predetermined line configurations using /(-piece mixed-graph representation of assembly; (2) Dimensional quality model of variation propagation for assembly processes with compliant parts; and (3) Evaluation of sequences based on the multivariate process capability index. The methodology is illustrated using an industrial case study.