47 research outputs found
Preliminary Analysis of Yeast Communities Associated with the Spontaneous Fermentation of Musalais, a Traditional Alcoholic Beverage of Southern Xinjiang, China
Musalais is a traditional alcoholic beverage made by the Uighur people in southern Xinjiang, China. Theinitial fermentation juice is obtained by prolonged boiling of local grape juice and grape residues. In thecurrent study, 242 yeast isolates were obtained from 18 samples (grapes, derived starting products, andprogressive stages of fermentation), and 20 phenotypes were distinguished, based on colony characteristicson WL nutrient agar. Fifty representative isolates were selected and found to belong to eight genera (basedon rRNA gene sequence analysis). Among the non-Saccharomyces species present on the grapes and relatedderived substrates, Hanseniaspora spp. was the dominant species. However, nearly all of these specieswere absent in early fermentation. Saccharomyces cerevisiae was not found until the onset of spontaneousfermentation and quickly became the dominant species. The identified yeast community could be used tofurther develop indigenous yeast strains to serve the traditional technology of Musalais. The productionof Musalais, from a starting substrate that has been boiled for 15 hours to kill all, or nearly all, yeast cells,provides fresh insights into the production of ethanol by the fermentation of grape juice
Restoration of Strength in Polyamide Woven Glass Fiber Organosheets by Hot Pressing
Thermoplastic composite organosheets (OSs) are increasingly recognized as a viable solution for automotive and aerospace structures, offering a range of benefits including cost-effectiveness through high-rate production, lightweight design, impact resistance, formability, and recyclability. This study examines the impact response, post-impact strength evaluation, and hot-pressing repair effectiveness of woven glass fiber nylon composite OSs across varying impact energy levels. Experimental investigations involved subjecting composite specimens to impact at varying energy levels using a drop-tower test rig, followed by compression-after-impact (CAI) tests. The results underscore the exceptional damage tolerance and improved residual compressive strength of the OSs compared to traditional thermoset composites. This enhancement was primarily attributed to the matrix’s ductility, which mitigated transverse crack propagation and significantly increased the amount of absorbed energy. To mitigate impact-induced damage, a localized hot-pressing repair approach was developed. This allowed to restore the post-impact strength of the OSs to pristine levels for impact energies below 40 J and by 83.6% for higher impact energies, when OS perforation was observed. The measured levels of post-repair strength demonstrate a successful restoration of OS strength over a wide range of impact energies, and despite limitations in achieving complete strength recovery above 40 J, hot-pressing repair emerges as a promising strategy for ensuring the longevity of thermoplastic composites through repairability
Secrecy Outage Probability of Relay Selection Based Cooperative NOMA for IoT Networks
As an important partner of fifth generation (5G) communication, the internet of things (IoT) is widely used in many fields with its characteristics of massive terminals, intelligent processing, and remote control. In this paper, we analyze security performance for the cooperative non-orthogonal multiple access (NOMA) networks for IoT, where the multi-relay Wyner model with direct link between the base station and the eavesdropper is considered. In particular, secrecy outage probability (SOP) for two kinds of relay selection (RS) schemes (i.e., single-phase RS (SRS) and two-phase RS (TRS)) is developed in the form of closed solution. As a benchmark for comparison, the SOP for random RS (RRS) is also obtained. To gain more meaningful insights, approximate derivations of SOP under the high signal-to-noise ratio (SNR) region are provided. Results of statistical simulation confirm the theoretical analysis and testify that: i) Compared with RRS scheme, SRS and TRS may improve secure performance because of obtaining smaller SOPs; ii) There exists secrecy performance floor for the SOP in strong SNR regime, which is dominated by NOMA protocol; iii) The security performance can be enhanced by augmenting the quantity of relays for SRS and TRS strategies. The purpose of this work is to provide theoretical basis for the analysis and design of anti-eavesdropping for NOMA systems in IoT
Quantifying the combined effects of multiple extreme floods on river channel geometry and on flood hazards
Effects of flood-induced bed elevation and channel geometry changes on flood hazards are largely unexplored, especially in the case of multiple floods from the same site. This study quantified the evolution of river channel and floodplain geometry during a repeated series of hypothetical extreme floods using a 2D full hydro-morphodynamic model (LHMM). These experiments were designed to examine the consequences of channel geometry changes on channel conveyance capacity and subsequent flood dynamics. Our results revealed that extreme floods play an important role in adjusting a river channel to become more efficient for subsequent propagation of floods, and that in-channel scour and sediment re-distribution can greatly improve the conveyance capacity of a channel for subsequent floods. In our hypothetical sequence of floods the response of bed elevation was of net degradation, and sediment transport successively weakened even with floods of the same magnitude. Changes in river channel geometry led to significant impact on flood hydraulics and thereby flood hazards. We found that flood-induced in-channel erosion can disconnect the channel from its floodplain resulting in a reduction of floodwater storage. Thus, the frequency and extent of subsequent overbank flows and floodplain inundation decreased, which reduced downstream flood attenuation and increased downstream flood hazard. In combination and in summary, these results suggest that changes in channel capacity due to extreme floods may drive changes in flood hazard. The assumption of unchanging of river morphology during inundation modelling should therefore be open to question for flood risk management
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Bicarbonate correction of ketoacidosis alters host-pathogen interactions and alleviates mucormycosis.
Patients with diabetic ketoacidosis (DKA) are uniquely predisposed to mucormycosis, an angioinvasive fungal infection with high mortality. Previously, we demonstrated that Rhizopus invades the endothelium via binding of fungal CotH proteins to the host receptor GRP78. Here, we report that surface expression of GRP78 is increased in endothelial cells exposed to physiological concentrations of β-hydroxy butyrate (BHB), glucose, and iron that are similar to those found in DKA patients. Additionally, expression of R. oryzae CotH was increased within hours of incubation with DKA-associated concentrations of BHB, glucose, and iron, augmenting the ability of R. oryzae to invade and subsequently damage endothelial cells in vitro. BHB exposure also increased fungal growth and attenuated R. oryzae neutrophil-mediated damage. Further, mice given BHB developed clinical acidosis and became extremely susceptible to mucormycosis, but not aspergillosis, while sodium bicarbonate reversed this susceptibility. BHB-related acidosis exerted a direct effect on both GRP78 and CotH expression, an effect not seen with lactic acidosis. However, BHB also indirectly compromised the ability of transferrin to chelate iron, as iron chelation combined with sodium bicarbonate completely protected endothelial cells from Rhizopus-mediated invasion and damage. Our results dissect the pathogenesis of mucormycosis during ketoacidosis and reinforce the importance of careful metabolic control of the acidosis to prevent and manage this infection
CotH3 mediates fungal invasion of host cells during mucormycosis.
Angioinvasion is a hallmark of mucormycosis. Previously, we identified endothelial cell glucose-regulated protein 78 (GRP78) as a receptor for Mucorales that mediates host cell invasion. Here we determined that spore coat protein homologs (CotH) of Mucorales act as fungal ligands for GRP78. CotH proteins were widely present in Mucorales and absent from noninvasive pathogens. Heterologous expression of CotH3 and CotH2 in Saccharomyces cerevisiae conferred the ability to invade host cells via binding to GRP78. Homology modeling and computational docking studies indicated structurally compatible interactions between GRP78 and both CotH3 and CotH2. A mutant of Rhizopus oryzae, the most common cause of mucormycosis, with reduced CotH expression was impaired for invading and damaging endothelial cells and CHO cells overexpressing GRP78. This strain also exhibited reduced virulence in a diabetic ketoacidotic (DKA) mouse model of mucormycosis. Treatment with anti-CotH Abs abolished the ability of R. oryzae to invade host cells and protected DKA mice from mucormycosis. The presence of CotH in Mucorales explained the specific susceptibility of DKA patients, who have increased GRP78 levels, to mucormycosis. Together, these data indicate that CotH3 and CotH2 function as invasins that interact with host cell GRP78 to mediate pathogenic host-cell interactions and identify CotH as a promising therapeutic target for mucormycosis