Ligand-based virtual screening, parallel solution-phase and microwave-assisted synthesis as tools to identify and synthesize new inhibitors of mycobacterium tuberculosis

In an attempt to identify new inhibitors of the growth of Mycobacterium tuberculosis (MTB), the causative agent of tuberculosis, a procedure for the generation, design, and screening of a ligand-based virtual library was applied. This used both an in silico protocol centered on a recursive partitioning (RP) model described herein, and a pharmacophoric model for antitubercular agents previously generated by our research group. Two candidates emerged from databases of commercially available compounds, both characterized by a minimum inhibitory concentration (MIC) of 25 microg mL(-1). Based on these compounds, two series of derivatives were synthesized by both parallel solution-phase and microwave-assisted synthesis, leading to enhanced antimycobacterial activity. During both the design and synthesis, attention was focused on the efficient allocation of available resources with the aim of reducing the overall costs associated with calculation and synthesis.     

Assembly of ligand-stripped nanocrystals into precisely controlled mesoporous architectures

The properties of mesoporous materials hinge on control of their composition, pore dimensions, wall thickness, and the size and shape of the crystallite building units. We create ordered mesoporous materials in which all of these parameters are independently controlled. Different sizes (from 4.5 to 8 nm) and shapes (spheres and rods) of ligand-stripped nanocrystals are assembled using the same structure-directing block copolymers, which contain a tethering domain designed to adsorb to their naked surfaces. Material compositions range from metal oxides (Sn-doped In(2)O(3) or ITO, CeO(2), TiO(2)) to metal fluorides (Yb,Er-doped NaYF(4)) and metals (FePt). The incorporation of new types of nanocrystals into mesoporous architectures can lead to enhanced performance. For example, TiO(2) nanorod-based materials withstand >1000 electrochemical cycles without significant degradation.     

Carotenoid composition of kale as influenced by maturity,season and minimal processing

The principal carotenoids of kale were identified by chemical reactions, high‐performance liquid chromatography/mass spectrometry and high‐performance liquid chromatography/photodiode array detection and were quantified by the last technique. In kale taken from conventional farms, the β‐carotene and lutein contents were significantly higher in the mature leaves, violaxanthin was at an unusually high level in the young leaves, and neoxanthin had practically the same concentration at both stages of maturity. In samples taken from an organic farm, the carotenoid contents were essentially the same in the young and the mature leaves. Except for β‐carotene, which did not differ with season, the carotenoid concentrations of marketed minimally processed kale were found to be significantly higher in the summer than in the winter, reflecting seasonal rather than processing effects. In minimally processed kale monitored during 5 days of storage at 7–9 °C, β‐carotene, lutein, violaxanthin and neoxanthin were reduced by 14, 27, 20 and 31% respectively. Thus minimal processing, seasonal and maturity factors were found to have an influence on the carotenoid content of kale. Copyright © 2004 Society of Chemical Industry     

Tackling 4G challenges with "TACT" - Design and optimization of 4G radio receivers with a transceiver architecture comparison tool (TACT)

Current integration trends imposed by the market are pushing toward the software radio paradigm. 4G radio receivers, where different wireless standards converge, make RF engineers face harder and harder challenges. Electronic design automation (EDA) tools play an increasing role in the design and verification of wireless system. This article presents a transceiver architecture comparison tool (TACT) which is a hierarchical, user-friendly, Matlab-based tool. It automates the design-space exploration procedure for 4G (fourth generation) wireless receivers. An example that considers a multistandard wideband code division multiple access (WCDMA)/wireless local area network (WLAN) receiver was also presented to illustrate the capabilities of TACT     

Characterization of α-Al2O3 supports modified with CeO2 and ZrO2

α-Al₂O₃ is a catalytic support adequate by its high stability, availability, and low cost, although it presents as principal disadvantage its limited surface area and reactivity. These disadvantages in the support lead to catalysts of low metallic dispersion and with weak interaction metal-support. According to characterization results obtained in this work, the addition of small amounts of Ce and Zr oxides to α-Al₂O₃ leads to Ce_xZr_1 ? xO₂ composites, thus conferring higher reactivity to the surface due to the presence of basic nature sites. This fact together with the well known oxygen storage capacity of these mixed oxides present in composites allow to obtain supports of optimal properties to prevent the sintering and the formation of superficial carbon present in the catalytic deactivation.     

Effects of nitrobenzene concentrations and hydraulic retention time on the treatment of nitrobenzene in sequential anaerobic baffled reactor and continuously stirred tank reactor system.

The effects of increasing nitrobenzene (NB) concentrations and hydraulic retention time (HRT) on the performance of anaerobic baffled reactor (ABR) and aerobic completely stirred tank reactor (CSTR) were studied. In the first step the NB concentration was increased from 30 to 700 mg/L at constant COD and flowrates. Maximum COD removal efficiencies in ABR varied between 88-92% as NB concentrations increased from 30 to 210 mg/L. After this dose, COD removal efficiency decreased to 85 and 79% at NB concentrations of 550 and 700 mg/L, respectively. Removal efficiencies of NB were nearly 100% for all NB concentrations in ABR reactor effluent. In the second step, COD and NB concentrations were kept constant while HRT decreased from 10.38 days to 1 day. As HRT decreased from 10.38 to 2.5 days the COD removal efficiencies in the anaerobic and anaerobic/aerobic reactor effluents were 92-94% and 97-98%, respectively. As HRT decreased from 2.5 days to 1 day COD removal efficiencies in the anaerobic and anaerobic/aerobic reactor effluents decreased to 83 and 95%, respectively. This study showed that HRT is a more important operation parameter than increasing NB concentration in ABR/CSTR sequential reactor system. Although ABR/CSTR system exhibited good COD and NB removal efficiencies, the lower HRTs slightly decreased the removal efficiencies compared to increasing NB concentration.     

When good news is bad news: Medical wellness as a nonevent in undergraduates.

Study 1 demonstrated that information about healthy functioning can amplify health concerns and erode diagnostic confidence. Undergraduate Ss received a hypothetical test showing some level of cells associated either with pathology or with its absence. The moderate wellness result produced low confidence in one's health estimate and was distressing to receive. Wellness information may represent an ambiguous nonevent when testing for disease. Study 2 tested this thesis by adding Ss who adopted a recovering role to those adopting an illness role. Judgmental uncertainty was greatest and equivalent among recovering Ss given the moderate illness result and among ailing Ss given a moderate wellness result, and both groups were most willing to consider taking a risky treatment for the disease. (PsycINFO Database Record (c) 2010 APA, all rights reserved)