1,407 research outputs found
Comparative analysis of newly identified rodent arteriviruses and porcine reproductive and respiratory syndrome virus to characterize their evolutionary relationships
Porcine reproductive and respiratory syndrome virus (PRRSV) has caused huge economic losses for the global pig industry, but its origins and evolution remain a mystery. In 2018, the genome sequences of seven arteriviruses isolated from rodents were determined, and here we publish new analysis showing that they may be ancestors of PRRSV. The sequence similarity of these viruses to PRRSV was ~60%, with shared genome organization and other characteristics, such as slippery sequences and C-rich motifs in nsp2, and a transactivated protein sequence in nsp1β. Codon usage basis analysis showed that PRRSV was closer to these rodent arteriviruses than lactate dehydrogenase-elevating virus (LDV) and they were both under pressure of natural selection. Evolutionary analysis revealed that four of the rodent arteriviruses shared the same genus with PRRSV, and were more closely related to PRRSV-2 than PRRSV-1. In addition to this, they all appeared earlier than PRRSV according to evolutionary modeling, and we speculate that they represent an intermediate step in the origin of PRRSV by arterivirus transmission from rodents to swine. Our in-depth analysis furthers our understanding of arteriviruses, and will serve as the basis for subsequent exploration of the evolution of PRRSV and other arteriviruses
CCDC50 Promotes Tumor Growth Through Regulation of Lysosome Homeostasis
The maintenance of lysosome homeostasis is crucial for cell growth. Lysosome-dependent degradation and metabolism sustain tumor cell survival. Here, we demonstrate that CCDC50 serves as a lysophagy receptor, promoting tumor progression and invasion by controlling lysosomal integrity and renewal. CCDC50 monitors lysosomal damage, recognizes galectin-3 and K63-linked polyubiquitination on damaged lysosomes, and specifically targets them for autophagy-dependent degradation. CCDC50 deficiency causes the accumulation of ruptured lysosomes, impaired autophagic flux, and superfluous reactive oxygen species, consequently leading to cell death and tumor suppression. CCDC50 expression is associated with malignancy, progression to metastasis, and poor overall survival in human melanoma. Targeting CCDC50 suppresses tumor growth and lung metastasis, and enhances the effect of BRAFV600E inhibition. Thus, we demonstrate critical roles of CCDC50-mediated clearance of damaged lysosomes in supporting tumor growth, hereby identifying a potential therapeutic target of melanoma
A simulation study on the measurement of D0-D0bar mixing parameter y at BES-III
We established a method on measuring the \dzdzb mixing parameter for
BESIII experiment at the BEPCII collider. In this method, the doubly
tagged events, with one decays to
CP-eigenstates and the other decays semileptonically, are used to
reconstruct the signals. Since this analysis requires good separation,
a likelihood approach, which combines the , time of flight and the
electromagnetic shower detectors information, is used for particle
identification. We estimate the sensitivity of the measurement of to be
0.007 based on a fully simulated MC sample.Comment: 6 pages, 7 figure
Modified acupuncture therapy, long-term acupoint stimulation versus sham control for weight control: a multicenter, randomized controlled trial
ObjectiveLong-term acupoint stimulation (LAS), also called embedding acupuncture, is a modified acupuncture technique. The preliminary results have demonstrated its efficacy in body-weight control. However, the low quality of available trials limited its application. This study aimed to evaluate the efficacy and safety of LAS in body-weight control by using a randomized, parallel, sham-controlled clinical trial design.MethodsThis was a randomized, single-blind, sham-controlled clinical trial including 84 adult participants (18–60 years) with a body mass index (BMI) of ≥ 24 kg/m2 conducted in three general hospitals in Shanghai, China. Participants were equally assigned to receive LAS or sham LAS (SLAS) once per 10 days, eight times in total. After completion, an additional intervention with a 3-month follow-up period was set to examine the continued effect of LAS. The primary outcome was the change in body weight from baseline to treatment endpoint within the intention-to-treat (ITT) analysis. Secondary outcomes contained changes in waist-to-hip ratio (WHR), lipid metabolism, and visceral and subcutaneous adipose tissues.ResultsFrom 14 May 2018 to 03 November 2019, 84 participants out of 201 screened individuals met the eligibility criteria, were randomized, and were analyzed (42 participants in each group). From baseline to treatment endpoint, the body-weight reduction in the LAS group was significantly larger than in the sham control (net difference: 1.57 kg, 95% CI: 0.29–2.86, p = 0.012). The superior weight reduction effect persisted in the follow-up period (net difference: 3.20 kg, 95% CI: 1.17–5.21, p = 0.001). LAS therapy also showed improvement in triglyceride and subcutaneous adipose tissue (SAT) compared with sham control. One participant in the LAS group reported a slightly uncomfortable and tingling sensation after the additional intervention. No other adverse events (AEs) were documented.ConclusionLAS, a modified acupuncture technique, is safe and effective in body-weight control. It could be used as an alternative choice to classical acupuncture for obesity management.Clinical Trial Registration[www.chictr.org.cn], identifier [ChiCTR1800015498]
Effects of Engineered Nanoparticles on the Assembly of Exopolymeric Substances from Phytoplankton
The unique properties of engineered nanoparticles (ENs) that make their industrial applications so attractive simultaneously raise questions regarding their environmental safety. ENs exhibit behaviors different from bulk materials with identical chemical compositions. Though the nanotoxicity of ENs has been studied intensively, their unintended environmental impacts remain largely unknown. Herein we report experimental results of EN interactions with exopolymeric substances (EPS) from three marine phytoplankton species: Amphora sp., Ankistrodesmus angustus and Phaeodactylum tricornutum. EPS are polysaccharide-rich anionic colloid polymers released by various microorganisms that can assemble into microgels, possibly by means of hydrophobic and ionic mechanisms. Polystyrene nanoparticles (23 nm) were used in our study as model ENs. The effects of ENs on EPS assembly were monitored with dynamic laser scattering (DLS). We found that ENs can induce significant acceleration in Amphora sp. EPS assembly; after 72 hours EN-EPS aggregation reached equilibrium, forming microscopic gels of ∼4–6 µm in size. In contrast, ENs only cause moderate assembly kinetic acceleration for A. angustus and P. tricornutum EPS samples. Our results indicate that the effects of ENs on EPS assembly kinetics mainly depend on the hydrophobic interactions of ENs with EPS polymers. The cycling mechanism of EPS is complex. Nonetheless, the change of EPS assembly kinetics induced by ENs can be considered as one potential disturbance to the marine carbon cycle
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Degradation aspects of water formation and transport in Proton Exchange Membrane Fuel Cell: A review
This review paper summarises the key aspects of Proton Exchange Membrane Fuel Cell (PEMFC) degradation that are associated with water formation, retention, accumulation, and transport mechanisms within the cell. Issues related to loss of active surface area of the catalyst, ionomer dissolution, membrane swelling, ice formation, corrosion, and contamination are also addressed and discussed. The impact of each of these water mechanisms on cell performance and durability was found to be different and to vary according to the design of the cell and its operating conditions. For example, the presence of liquid water within Membrane Electrode Assembly (MEA), as a result of water accumulation, can be detrimental if the operating temperature of the cell drops to sub-freezing. The volume expansion of liquid water due to ice formation can damage the morphology of different parts of the cell and may shorten its life-time. This can be more serious, for example, during the water transport mechanism where migration of Pt particles from the catalyst may take place after detachment from the carbon support. Furthermore, the effect of transport mechanism could be augmented if humid reactant gases containing impurities poison the membrane, leading to the same outcome as water retention or accumulation.
Overall, the impact of water mechanisms can be classified as aging or catastrophic. Aging has a long-term impact over the duration of the PEMFC life-time whereas in the catastrophic mechanism the impact is immediate. The conversion of cell residual water into ice at sub-freezing temperatures by the water retention/ accumulation mechanism and the access of poisoning contaminants through the water transport mechanism are considered to fall into the catastrophic category. The effect of water mechanisms on PEMFC degradation can be reduced or even eliminated by (a) using advanced materials for improving the electrical, chemical and mechanical stability of the cell components against deterioration, and (b) implementing effective strategies for water management in the cell
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