Biotyping Saccharomyces cerevisiae strains using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS)

Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS), a powerful biotyping tool for the identification of bacteria and clinical yeast isolates, was investigated as a method to rapidly identify industrial S. cerevisiae strains. In this study, an optimized sample preparation protocol was devised for the biotyping of S. cerevisiae strains. The results demonstrate that ethanol/formic acid protein extraction, of a cell density of 1 × 10⁸ cells co-crystallized with α-cyano-4-hydroxycinnmaic acid, is required to yield mass spectral profiles that are diagnostic of each strain type. Forty-four S. cerevisiae strains commonly employed in South African fermentation-based industries were biotyped in an attempt to create a yeast reference database within a local context. The data revealed that MALDI-TOF MS can be used for the rapid and accurate identification of laboratory and industrial S. cerevisiae strains.     

Dynamic voltage restorer based on a four-leg voltage source converter

Analysis and control of a dynamic voltage restorer are described. The voltage restorer is based on a four-leg voltage source converter. The three-phase input variables are resolved into the positive, negative and zero-sequence components using a weighted, recursive, least-squares estimator. Identical controllers have been used for each sequence component. A laboratory model of the restorer has been constructed and its performance has been tested by simulation and experiments.     

Novel hybrid polymer photovoltaics made by generating silver nanoparticles in polymer:fullerene bulk-heterojunction structures

Here, we developed the high efficient poly(3-hexylthiophene) (P3HT):[6,6]-phenyl C₆₁-butyric acid butyl ester (PCBB):Ag nanoparticle hybrid photovoltaic cells by generating the silver nanoparticles in the bulk-heterojunction structures of P3HT:PCBB prior to the spin-coating process. Hybrid bulk-heterojunction solar cells with an ITO/(G)-PEDOT/P3HT:PCBB:Ag/Al was fabricated, which shows open-circuit voltage, short-circuit current density, and power conversion efficiency of 0.639 V, 12.29 mA/cm², and 4.30% under AM1.5 irradiation (100 mW/cm²), respectively.     

Enzyme-Assisted Process for Production of Superior Quality Vanilla Extracts from Green Vanilla Pods Using Tea Leaf Enzymes

Vanilla planifolia Andrews is a perennial tropical vine and is an orchid grown for its pleasant flavor. There is an increasing trend world over for using natural flavors. Vanilla being an important food flavoring ingredient, the demand for natural vanilla extract is increasing. Hence, the aim of the present study was to prepare vanilla extract from green beans without going through the elaborate and time-consuming conventional curing process. Vanilla beans after size reduction were mixed in a suitable proportion with tea leaf enzyme extract (TLEE) and incubated to facilitate action of enzymes on vanilla flavor precursors. The beans mix was squeezed, and the filtrate was treated with ethanol to extract the vanilla flavor. TLEE-treated extracts had higher vanillin content (4.2%) compared to Viscozyme extract (2.4%). Also, it had higher intensity of vanilla flavor, sweet, and floral notes. Further, electronic nose analysis confirmed the discrimination between extracts. It was concluded that the use of TLEE is very much useful to obtain higher yield of vanilla extract and superior quality vanilla flavor, which avoids the traditional laborious and time-consuming curing process.     

Structural and functional properties of sol-gel synthesized and microwave heated Pb0.8 Co0.2-zLazTiO3 (z = 0.05–0.2) nanoparticles

The present work reports the effect of La-substitution on structural and functional properties of lead cobalt titanate (PCT) perovskite structure as a function of variation of Co-content. The sol-gel synthesized and microwave heated Pb_0.8 Co_0.2-zLa_zTiO₃ (z?=?0.05, 0.1, 0.15 & 0.2) (PCLT) nanoparticles showed the presence of complete cubic phases while few were noted to be tetragonal lead titanate (PT) phases. The surface morphology was examined by field emission scanning electron microscope (FESEM) and high resolution transmission electron microscope (HRTEM). The HRTEM revealed fibers like nanoparticles at z?=?0.15 and 0.2. The Fourier transform infrared spectra attributed the presence of metal oxide bonds. Furthermore, the wide optical band gap energy (E_op) was acquired to be changing from 2.32 to 3.20?eV. In addition, the electrical parameters such as dielectric constant (ε'), dielectric loss (ε"), ac & dc-electrical conductivity (σ_ac & σ_dc), complex dielectric modulus (M^*) and complex impedance (Z^*) were studied as a function of frequency (f) and composition. Using power law fitting, the σ_dc values were determined. The z?=?0.15 content exhibited high σ_dc of ~ 2.51?×?10^?7 S/cm among all compositions. Besides, the results expressed the existence of short range and long range hopping conduction regions in dielectric modulus spectra. The Nyquist plots were drawn to elucidate the electrical conduction and relaxation mechanism. Later on, ferroelectric hysteresis loops were recorded for z?=?0.05–0.2.     

Nanostructured Carbon Nitrides for CO2 Capture and Conversion

Carbon nitride (CN), a 2D material composed of only carbon (C) and nitrogen (N), which are linked by strong covalent bonds, has been used as a metal-devoid and visible-light-active photocatalyst owing to its magnificent optoelectronic and physicochemical properties including suitable bandgap, adjustable energy-band positions, tailor-made surface functionalities, low cost, metal-free nature, and high thermal, chemical, and mechanical stabilities. CN-based materials possess a lot of advantages over conventional metal-based inorganic photocatalysts including ease of synthesis and processing, versatile functionalization or doping, flexibility for surface engineering, low cost, sustainability, and recyclability without any leaching of toxic metals from photocorrosion. Carbon nitrides and their hybrid materials have emerged as attractive candidates for CO₂ capture and its reduction into clean and green low-carbon fuels and valuable chemical feedstock by using sustainable and intermittent renewable energy sources of sunlight and electricity through the heterogeneous photo(electro)catalysis. Here, the latest research results in this field are summarized, including implementation of novel functionalized nanostructured CNs and their hybrid heterostructures in meeting the stringent requirements to raise the efficiency of the CO₂ reduction process by using state-of-the-art photocatalysis, electrocatalysis, photoelectrocatalysis, and feedstock reactions. The research in this field is primarily focused on advancement in the synthesis of nanostructured and functionalized CN-based hybrid heterostructured materials. More importantly, the recent past has seen a surge in studies focusing significantly on exploring the mechanism of their application perspectives, which include the behavior of the materials for the absorption of light, charge separation, and pathways for the transport of CO₂ during the reduction process.     

Subjective past, present, and future fit: Effects on anxiety, depression, and other indicators of well-being.

207 undergraduates preparing for annual academic examinations at an Indian university completed self-administered questionnaires measuring the effects of subjective current, retrospected, and anticipated person–environment fit on affective and somatic strain and well-being. A distinction was made between cognitive (e.g., meeting demands for intelligence, good memory) and motivational (e.g., being able to muster the effort) fit. Results show that poor cognitive fit had a greater effect on predicting high levels of strain across all time frames, but did best in the past and current frames. Poor motivational fit had its greatest effect on strain when fit dealt with anticipated or current fit. It is suggested that the more subjectively uncontrollable a dimension of fit, the more salient it is in the past time frame; the more subjectively controllable the dimension, the more salient it is in the future time frame. Scales to measure fit and strain and well-being are appended, as are their means, standard deviations, and reliabilities. (53 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A high-efficiency high-power-generation system for automobiles

This paper presents a new scheme for the efficient generation of high electric power demanded for future automobiles. The new system consists of a permanent-magnet (PM) alternator having high-energy MAGNEQUENCH (MQ) magnets and split winding and a novel electronic voltage regulation scheme. A proof-of-concept system, capable of providing 100/250 A (idle/cruising) at 14 V, has been built and tested in the laboratory with encouraging results. This high output is provided at 15-20 percentage points higher efficiencies than conventional automotive alternators, which translates into considerable fuel economy savings. The system is 8 dB quieter and has a rotor inertia of only 2/3 that of an equivalent production alternator, thus allowing for a belt drive without excessive slippage     

Power reduction methods for NMOS dynamic random access memories

Power reduction methods for NMOS dynamic random access memories are proposed which reduce power dissipation. As the bit density increases in NMOS dynamic random access memories the power dissipation increases. A major consideration in the design of megabit dynamic random access memories is the power supply voltage. The power supply voltage mainly depends upon the following factors: power dissipation; reliability, such as high field effects due to small device size; memory cell operating margin. Power dissipation in decoders and 1 megabit NMOS dynamic random access memory chips are discussed. The basic properties of the proposed methods and a prototype VLSI implementation are discussed. In order to meet user power supply requirements, the proposed power reduction methods are useful for future megabit NMOS dynamic random access memories.     

Expression of c-erbB3 protein in primary breast carcinomas

Expression of c-erbB3 protein was investigated in 104 primary breast carcinomas comprising nine comedo ductal carcinoma in situ (DCIS), 91 invasive ductal carcinomas and four invasive lobular carcinomas using two monoclonal antibodies, RTJ1 and RTJ2. Of the 91 invasive ductal carcinomas, seven contained the comedo DCIS component adjacent to the invasive component. An immunohistochemical technique was used to evaluate the association between expression of c-erbB3 and clinical parameters and tumour markers such as epidermal growth factor receptor (EGFR), c-erbB2, cathepsin-D and p53 in archival formalin-fixed paraffin-embedded tumour tissues. Our results indicated that RTJ1 and RTJ2 gave identical staining patterns and concordant results. It was found that the overexpression of c-erbB3 protein was observed in 67% (6/9) of comedo DCIS, 52% (44/84) of invasive ductal carcinomas, 71% (5/7) of carcinomas containing both the in situ and invasive lesions and 25% (1/4) of invasive lobular carcinomas. A significant relationship (P < 0.05) was observed between strong immunoreactivity of c-erbB3 protein and histological grade, EGFR and cathepsin-D, but not with expression of c-erbB2, p53, oestrogen receptor status, lymph node metastases or age of patient. However, we noted that a high percentage of oestrogen receptor-negative tumours (59%), lymph node-positive tumours (63%) and c-erbB2 (63%) were strongly positive for c-erbB3 protein. We have also documented that a high percentage of EGFR (67%), c-erbB2 (67%), p53 (75%) and cathepsin-D-positive DCIS (60%) were strongly positive for c-erbB3. These observations suggest that overexpression of c-erbB3 protein could play an important role in tumour progression from non-invasive to invasive and, also, that it may have the potential to be used as a marker for poor prognosis of breast cancer.