The development of risk assessment models for carpal tunnel syndrome: a case-referent study

The present study developed risk assessment models for carpal tunnel syndrome (CTS) which can provide information of the likelihood of developing CTS for an individual having certain personal characteristics and occupational risks. A case-referent study was conducted consisting of two case groups and one referent group: (1) 22 work-related CTS patients (W-CTS), (2) 25 non-work related CTS patients (NW-CTS), and (3) 50 healthy workers (HEALTHY) having had no CTS history. The classification of CTS patients into one of the case groups was determined according to the type of insurance covering their medical costs. Personal characteristics, psychosocial stresses at work, and physical work conditions were surveyed by using a questionnaire tailor-designed to CTS (reliability of each scale > or = 0.7). By contrasting the risk information of each case group to that of the referent group, three logistic regression models were developed: W-CTS/HEALTHY, NW-CTS/HEALTHY, and C-CTS/HEALTHY (C-CTS, the combined group of W-CTS and NW-CTS). ROC analysis indicated that the models have satisfactory discriminability (d' = 1.91 to 2.51) and high classification accuracy (overall accuracy = 83-89%). Both W-CTS/HEALTHY and C-CTS/HEALTHY include personal and physical factors, while NW-CTS/HEALTHY involves only personal factors. This suggests that the injury causation of NW-CTS patients should be attributable mainly to their 'high' personal susceptibility to the disorder rather than exposure to adverse work conditions, while that of W-CTS patients be attributable to improper work conditions and CTS-prone personal characteristics in combination.     

Simple HPLC Method for Resolution of Curcuminoids with Antioxidant Potential

ABSTRACT:  Development of methodology for qualitative analysis and quantitative separation of individual curcuminoids in curcumin removed turmeric oleoresin (CRTO) and study of antioxidant activity of individual curcuminoids have been achieved in the present study. A simple HPLC protocol was outlined for optimal resolution of curcuminoids (I), (II), and (III) on an Exil-NH₂ column using isocratic elution with a mixture of isopropanol and water. CRTO is shown to be good source for the compounds II and III, as they are in an enriched form. The optimum resolution of the curcumin and its analogs in the present method developed, affords a facile method for estimation of individual curcuminoids in turmeric samples, which is an improvement over the standard AOAC method which estimates only total curcuminoids. The free radical scavenging capacity of pure curcuminoids I, II, and III, as determined by DPPH method at 100 ppm concentration was 88%, 80%, and 68% with IC₅₀ values being 56, 62, and 73 ppm, respectively. Their antioxidant potential could render them useful as important nutraceuticals or functional food ingredients.     

Nonlinear finite element analysis of laminated composite shells in hygrothermal environments

The large deflection bending behaviour of composite cylindrical shell panels subjected to hygrothermal environments is investigated in this paper. The present finite element formulation considers doubly curved thick shells and includes large deformations with Green–Lagrange strains. The analysis is carried out using quadratic eight-noded isoparametric element and the problem is solved using the incremental modified Newton–Raphson scheme. A parametric study is carried out varying the curvature ratios of composite cylindrical shell panels with simply supported and clamped support conditions.     

X-ray absorption and micro X-ray fluorescence spectroscopy investigation of copper and zinc speciation in biosolids

Despite its pivotal role in determining the risks and time frames associated with contaminant release, metal speciation remains a poorly understood aspect of biosolids chemistry. The work reported here used synchrotron-based spectroscopy techniques to investigate the speciation of copper and zinc in a range of Australian biosolids. High resolution element mapping of biosolids samples using micro X-ray fluorescence spectroscopy revealed considerable heterogeneity in key element associations, and a combination of both organic and inorganic copper and zinc binding environments. Linear combination fitting of K-edge X-ray absorption spectra indicated consistent differences in metal speciation between freshly produced and stockpiled biosolids. While sulfide minerals play a dominant role in metal binding in freshly dewatered biosolids, they are of lesser importance in dried biosolids that have been stockpiled. A degree of metal binding with iron oxide minerals was apparent but the results did not support the hypothesis that biosolids metals are chiefly associated with iron minerals. This work has potential implications for the long-term stability of metals in biosolids and their eventual fate following land application.     

Synthesis and photovoltaic properties of novel PPV-derivatives tethered with spiro-bifluorene unit for polymer solar cells

New thermally robust photoactive arylenevinylene-based conjugated polymers, poly[3,6-bis(3,7-dimethyloctyloxy)-9,9-spirobifluorenyl-2,7-vinylene] [(OC₁₀)₂-spiro-PFV] and poly[{3,6-bis(3,7-dimethyloctyloxy)-9,9-spirobifluorenyl-2,7-vinylene}-co-2-{methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene}] [(OC₁₀)₂-spiro-PFV-co-MEH-PPV], were synthesized and used to fabricate polymer solar cells. Bulk heterojunction solar cells fabricated by blending the new copolymers, spiro-PFV and (OC₁₀)₂-spiro-PFV-co-MEH-PPV, as an electron donor with the fullerene derivative, [6,6]-phenyl C₆₁ butyric acid methyl ester (PCBM) as an electron acceptor. The effects of electron donor to acceptor ratio, thickness of photoactive layer, and the cathode structures on the power conversion efficiency (PCE) in polymer solar cells were studied. The copolymer feed ratio was found to have a considerable effect on the PCE. The maximum PCE of 1.30% was achieved with (OC₁₀)₂-spiro-PFV-co-MEH-PPV.     

Quick resource allocation in heterogeneous networks

Wireless Networks - In this paper, an innovative technique is given to reduce the implementation time taken for doing the seamless communication in heterogeneous networks. When a new user arrives...     

Dithiocarbamates as a Sensitive Electroanalytical Reagent: Determination of Chromium by Catalytic Hydrogen Wave at DME in Water Systems and Vegetables

Simple, sensitive catalytic hydrogen polarographic method was developed for the determination of chromium (VI) with ammonium piperidine dithiocarbamate (Amm Pip-DTC) and ammonium morpholine dithiocarbamate (Amm Mor-DTC) in various water systems and vegetables. The method was based on the catalytic hydrogen wave of Amm Pip-DTC-Cr(VI) and Amm Mor-DTC-Cr(VI) complexes in the presence of NH₄Cl–NH₄OH medium at pH 7.5 and 9.6 and produce a catalytic hydrogen waves at −1.59 and −1.65 V Vs SCE, respectively. Various optimum parameters such as effect of pH, NH₄Cl–NH₄OH, Pip-DTC, metal ion concentrations and excipient effect on peak height were investigated to enhance the sensitivity, selectivity, and detection limits of the present method and compared in terms of Students t test and variance ratio f test with differential pulse polarography (DPP) method. The proposed method was applied for the determination of chromium (VI) in various water system and vegetables and the results obtained were in good agreement with DPP.     

Application of the singular perturbation method to a steam power system

A fifth-order steam power system with reheat unit is considered. The discrete model of the continuous system is cast in the singularity perturbed form. A perturbation method is applied to the discrete model. The important features of singular perturbations in discrete systems are clearly illustrated. The numerical values represent a typical set of real data. The results show a new avenue for the application of the singular perturbation method to discrete models of large-scale power systems.