Fermented foods and beverages possess various nutritional and therapeutic properties. Lactic acid bacteria (LAB) play a major role in determining the positive health effects of fermented milks and ...related products. The L. acidophilus and Bifidobacteria spp are known for their use in probiotic dairy foods. Cultured products sold with any claim of health benefits should meet the criteria of suggested minimum number of more than 10⁶ cfu/g at the time of consumption. Yoghurt is redefined as a probiotic carrier food. Several food powders like yoghurt powder and curd (dahi) powder are manufactured taking into consideration the number of organisms surviving in the product after drying. Such foods, beverages and powders are highly acceptable to consumers because of their flavor and aroma and high nutritive value. Antitumor activity is associated with the cell wall of starter bacteria and so the activity remains even after drying. Other health benefits of fermented milks include prevention of gastrointestinal infections, reduction of serum cholesterol levels and antimutagenic activity. The fermented products are recommended for consumption by lactose intolerant individuals and patients suffering from atherosclerosis. The formulation of fermented dietetic preparations and special products is an expanding research area. The health benefits, the technology of production of fermented milks and the kinetics of lactic acid fermentation in dairy products are reviewed here.
Performance in terms of axial and radial temperature distributions, thermal efficiency, and CO and NOx emissions of a medium-scale liquefied petroleum gas cooking stove with a two-layer porous ...radiant burner is reported. In the two-layer burner, SiC porous matrix acts as the combustion zone, and the preheating zone consists of an alumna matrix. With burner power in the range 5–10 kW, effects of equivalence ratio on radial and axial temperature distributions, thermal efficiency and emissions are investigated. For comparison, axial temperature distributions, thermal efficiency and emissions of CO and NOx for conventional burner working in the free-flame mode are also reported. With the porous radiant burner, radial temperature distributions are almost uniform, the maximum thermal efficiency is 28% higher, and CO and NOx emissions are significantly low.
•Performance characterization of LPG cooking stove is done.•Burner of the stove is composed of a two layer porous matrix.•Input power of the stove ranges from 5 to 15 kW.•Measured temperature distributions, thermal efficiency and CO and NOx emissions are reported.•Thermal efficiency is more and emissions of CO and NOx are less than conventional LPG stove.
: Yogurt is a basic dairy product that has been consumed for centuries as a part of the diet, even when its beneficial effects were neither fully known nor scientifically proven. With time, yogurt ...has been continuously modified to obtain a product with better appeal and nutritional effects. The flavor components of yogurt are affected because of these modifications. The present review article is focused on the influence of the different parameters and modifications on aroma and taste components of yogurt. Extensive work has been done to explore the effect of chemical components as well as the microbial, processing, and storage aspects. The popularity of yogurt as a food component depends mainly on its sensory characteristics, of which aroma and taste are most important. This review also outlines the effects of the different modifications attempted in the composition of yogurt.
Many bacterial pathogens achieve resistance to defensin-like cationic antimicrobial peptides (CAMPs) by the multiple peptide resistance factor (MprF) protein. MprF plays a crucial role in ...Staphylococcus aureus virulence and it is involved in resistance to the CAMP-like antibiotic daptomycin. MprF is a large membrane protein that modifies the anionic phospholipid phosphatidylglycerol with l-lysine, thereby diminishing the bacterial affinity for CAMPs. Its widespread occurrence recommends MprF as a target for novel antimicrobials, although the mode of action of MprF has remained incompletely understood. We demonstrate that the hydrophilic C-terminal domain and six of the fourteen proposed trans-membrane segments of MprF are sufficient for full-level lysyl-phosphatidylglycerol (Lys-PG) production and that several conserved amino acid positions in MprF are indispensable for Lys-PG production. Notably, Lys-PG production did not lead to efficient CAMP resistance and most of the Lys-PG remained in the inner leaflet of the cytoplasmic membrane when the large N-terminal hydrophobic domain of MprF was absent, indicating a crucial role of this protein part. The N-terminal domain alone did not confer CAMP resistance or repulsion of the cationic test protein cytochrome c. However, when the N-terminal domain was coexpressed with the Lys-PG synthase domain either in one protein or as two separate proteins, full-level CAMP resistance was achieved. Moreover, only coexpression of the two domains led to efficient Lys-PG translocation to the outer leaflet of the membrane and to full-level cytochrome c repulsion, indicating that the N-terminal domain facilitates the flipping of Lys-PG. Thus, MprF represents a new class of lipid-biosynthetic enzymes with two separable functional domains that synthesize Lys-PG and facilitate Lys-PG translocation. Our study unravels crucial details on the molecular basis of an important bacterial immune evasion mechanism and it may help to employ MprF as a target for new anti-virulence drugs.
Development of in vivo daptomycin resistance (DAP-R) among Staphylococcus aureus clinical isolates, in association with clinical treatment failures, has become a major therapeutic problem. This issue ...is especially relevant to methicillin-resistant S. aureus (MRSA) strains in the context of invasive endovascular infections. In the current study, we used three well-characterized and clinically-derived DAP-susceptible (DAP-S) vs. resistant (DAP-R) MRSA strain-pairs to elucidate potential genotypic mechanisms of the DAP-R phenotype. In comparison to the DAP-S parental strains, DAP-R isolates demonstrated (i) altered expression of two key determinants of net positive surface charge, either during exponential or stationary growth phases (i.e., dysregulation of dltA and mprF), (ii) a significant increase in the D-alanylated wall teichoic acid (WTA) content in DAP-R strains, reflecting DltA gain-in-function; (iii) heightened elaboration of lysinylated-phosphatidylglyderol (L-PG) in DAP-R strains, reflecting MprF gain-in-function; (iv) increased cell membrane (CM) fluidity, and (v) significantly reduced susceptibility to prototypic cationic host defense peptides of platelet and leukocyte origins. In the tested DAP-R strains, genes conferring positive surface charge were dysregulated, and their functionality altered. However, there were no correlations between relative surface positive charge or cell wall thickness and the observed DAP-R phenotype. Thus, charge repulsion mechanisms via altered surface charge may not be sufficient to explain the DAP-R outcome. Instead, changes in the compositional or biophysical order of the DAP CM target of such DAP-R strains (i.e., increased fluidity) may be essential to this phenotype. Taken together, DAP-R in S. aureus appears to involve multi-factorial and strain-specific adaptive mechanisms.
Soil salinity is one of the most devastating factors threatening cultivable land. While low to moderate salt stress affects the plant growth rate and yields, the high‐salt stress conditions are ...detrimental for plant growth. The problem of salinity is often compounded by mineral deficiencies and toxicities. Rice is essentially rated as salt‐sensitive crop and its salt susceptibility is dependent on the growth stage. The genetic processes that are involved in coordinating the responses to salinity in rice are not very clearly understood, but can be somewhat explained by mechanisms that regulate ion homeostasis, osmolyte production, scavenging of toxic radicals, water conduction and root–shoot response coordination. This is achieved by modifying the gene expression. The microRNAs (miRs) represent an important class of endogenous small RNAs that have the potential to regulate gene expression at post‐transcriptional levels. This review discusses the impact of salinity on rice crop and the current knowledge in the area of miRs with their role in the adaptive response to salt and other abiotic stresses, with a focus on rice.
H1 linker histones are the most abundant chromatin-binding proteins
. In vitro studies indicate that their association with chromatin determines nucleosome spacing and enables arrays of nucleosomes ...to fold into more compact chromatin structures. However, the in vivo roles of H1 are poorly understood
. Here we show that the local density of H1 controls the balance of repressive and active chromatin domains by promoting genomic compaction. We generated a conditional triple-H1-knockout mouse strain and depleted H1 in haematopoietic cells. H1 depletion in T cells leads to de-repression of T cell activation genes, a process that mimics normal T cell activation. Comparison of chromatin structure in normal and H1-depleted CD8
T cells reveals that H1-mediated chromatin compaction occurs primarily in regions of the genome containing higher than average levels of H1: the chromosome conformation capture (Hi-C) B compartment and regions of the Hi-C A compartment marked by PRC2. Reduction of H1 stoichiometry leads to decreased H3K27 methylation, increased H3K36 methylation, B-to-A-compartment shifting and an increase in interaction frequency between compartments. In vitro, H1 promotes PRC2-mediated H3K27 methylation and inhibits NSD2-mediated H3K36 methylation. Mechanistically, H1 mediates these opposite effects by promoting physical compaction of the chromatin substrate. Our results establish H1 as a critical regulator of gene silencing through localized control of chromatin compaction, 3D genome organization and the epigenetic landscape.
The purpose of this study was to evaluate the oncologic safety of submental island flap (SIF) reconstruction in clinically node-negative oral cancer patients. Forty-four clinically node-negative oral ...cancer patients with tumour size T1–T3 were divided into two groups. The Submental group consisted of 21 patients, who underwent submental island flap reconstruction whereas the control group consisted of 23 patients who underwent reconstruction with other locoregional or free flaps. The locoregional recurrence rate (LRR) and recurrence-free survival (RFS) in these two groups were assessed and compared. The follow-up period in the two groups ranged from six to 28 months, with a median follow-up period of 15 months and 21 months, respectively. Results showed that the LRR in the control and the submental group was 21.7% and 19%, respectively (p = 0.825). Kaplan–Meier curve showed that the difference in recurrence-free survival in the two groups was not statistically significant (p = 0.749). Multivariate and bivariate analyses did not establish any relationship between the predictive parameters and locoregional recurrence. Thus, the Submental island flap is a reliable and versatile locoregional flap for the reconstruction of post-resection defects in oral cancer. It has no predictive influence on locoregional recurrence in clinically node-negative oral cancer patients.
The growth of graphene on SiC/Si substrates is an appealing alternative to the growth on bulk SiC for cost reduction and to better integrate the material with Si based electronic devices. In this ...paper, we present a thorough in situ study of the growth of epitaxial graphene on 3C SiC (111)/Si (111) substrates via high temperature annealing (ranging from 1125 to 1375°C) in ultra high vacuum (UHV). The quality and number of graphene layers have been investigated by using X-ray Photoelectron Spectroscopy (XPS), while the surface characterization have been studied by Scanning Tunnelling Microscopy (STM). Ex-situ Raman spectroscopy measurements confirm our findings, which demonstrate the exponential dependence of the number of graphene layers on the annealing temperature.
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