Removal of bisphenol, using antimony nanoparticle multi-walled carbon nanotubes composite from aqueous solutions

This study focuses on preparing Antimony Nanoparticle Multi-walled Carbon (ANMWC) composite as an effective adsorbent and then the effect of produced composite in BPA removal from aqueous solutions was studied. ANMWC were prepared using chemical method and characterized with X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and Brunauer-Emmett-Teller (BET). Moreover, the removal efficiency of prepared AMWCNT and Nanoparticle Multi-walled Carbon (MWCNT) in removal of Bisphenol A was investigated. Results revealed that the BPA removal efficiency by AMWCNT increased from 80 to 93 with the increase of contact time 5 to 60 min. The maximum removal efficiency for the both adsorbents was seen at pH 7, which was 85 for MWCNT and 95 for ANMWC composite. According to the results obtained, pHzpc for both adsorbents was 7. Results showed that the adsorption process followed the pseudo-first order model with a high correlation value and BPA adsorption on MWCNT followed the Langmuir isotherm model

Sample matching by inferred agonal stress in gene expression analyses of the brain

<p>Abstract</p> <p>Background</p> <p>Gene expression patterns in the brain are strongly influenced by the severity and duration of physiological stress at the time of death. This agonal effect, if not well controlled, can lead to spurious findings and diminished statistical power in case-control comparisons. While some recent studies match samples by tissue pH and clinically recorded agonal conditions, we found that these indicators were sometimes at odds with observed stress-related gene expression patterns, and that matching by these criteria still sometimes results in identifying case-control differences that are primarily driven by residual agonal effects. This problem is analogous to the one encountered in genetic association studies, where self-reported race and ethnicity are often imprecise proxies for an individual's actual genetic ancestry.</p> <p>Results</p> <p>We developed an Agonal Stress Rating (ASR) system that evaluates each sample's degree of stress based on gene expression data, and used ASRs in <it>post hoc </it>sample matching or covariate analysis. While gene expression patterns are generally correlated across different brain regions, we found strong region-region differences in empirical ASRs in many subjects that likely reflect inter-individual variabilities in local structure or function, resulting in region-specific vulnerability to agonal stress.</p> <p>Conclusion</p> <p>Variation of agonal stress across different brain regions differs between individuals, revealing a new level of complexity for gene expression studies of brain tissues. The Agonal Stress Ratings quantitatively assess each sample's extent of regulatory response to agonal stress, and allow a strong control of this important confounder.</p

Informational entropy : a failure tolerance and reliability surrogate for water distribution networks

Evolutionary algorithms are used widely in optimization studies on water distribution networks. The optimization algorithms use simulation models that analyse the networks under various operating conditions. The solution process typically involves cost minimization along with reliability constraints that ensure reasonably satisfactory performance under abnormal operating conditions also. Flow entropy has been employed previously as a surrogate reliability measure. While a body of work exists for a single operating condition under steady state conditions, the effectiveness of flow entropy for systems with multiple operating conditions has received very little attention. This paper describes a multi-objective genetic algorithm that maximizes the flow entropy under multiple operating conditions for any given network. The new methodology proposed is consistent with the maximum entropy formalism that requires active consideration of all the relevant information. Furthermore, an alternative but equivalent flow entropy model that emphasizes the relative uniformity of the nodal demands is described. The flow entropy of water distribution networks under multiple operating conditions is discussed with reference to the joint entropy of multiple probability spaces, which provides the theoretical foundation for the optimization methodology proposed. Besides the rationale, results are included that show that the most robust or failure-tolerant solutions are achieved by maximizing the sum of the entropies

Bacterial contamination of inanimate surfaces and equipment in the intensive care unit

Intensive care unit (ICU)-acquired infections are a challenging health problem worldwide, especially when caused by multidrug-resistant (MDR) pathogens. In ICUs, inanimate surfaces and equipment (e.g., bedrails, stethoscopes, medical charts, ultrasound machine) may be contaminated by bacteria, including MDR isolates. Cross-transmission of microorganisms from inanimate surfaces may have a significant role for ICU-acquired colonization and infections. Contamination may result from healthcare workers' hands or by direct patient shedding of bacteria which are able to survive up to several months on dry surfaces. A higher environmental contamination has been reported around infected patients than around patients who are only colonized and, in this last group, a correlation has been observed between frequency of environmental contamination and culture-positive body sites. Healthcare workers not only contaminate their hands after direct patient contact but also after touching inanimate surfaces and equipment in the patient zone (the patient and his/her immediate surroundings). Inadequate hand hygiene before and after entering a patient zone may result in cross-transmission of pathogens and patient colonization or infection. A number of equipment items and commonly used objects in ICU carry bacteria which, in most cases, show the same antibiotic susceptibility profiles of those isolated from patients. The aim of this review is to provide an updated evidence about contamination of inanimate surfaces and equipment in ICU in light of the concept of patient zone and the possible implications for bacterial pathogen cross-transmission to critically ill patients

The Li1+xMn2O4C system Materials and electrochemical aspects

The importance of the synthesis conditions of Li1+xMn2O4 on its electrochemical performance, namely, capacity fading and initial capacity is discussed. By using a well-defined thermal treatment and a particular nominal composition, x=0.05, one can overcome the problem of capacity fading that was previously experienced with LiMn4 while, at the same time, enhancing the usable capacity. The importance of the thermal treatment in terms of oxygen stoichiometry effects and how cyclic voltammetry can be used to optimize Li1 + xMn2O4 powders have been discussed. © 1995 Elsevier Science S.A. All rights reserved