Advanced c/Sic-SiHfBcN composites were prepared by modification of the matrix of c/Siccomposites with single-source-precursor derived SiHfBcN ceramics. Ultra-high temperature oxidation behavior of the c/SicSiHfBcN co...
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Advanced c/Sic-SiHfBcN composites were prepared by modification of the matrix of c/Siccomposites with single-source-precursor derived SiHfBcN ceramics. Ultra-high temperature oxidation behavior of the c/SicSiHfBcN composites under laser heating were systematically studied. The influence of temperature, preform structure and precursor on oxidation resistance of the composites were analyzed. The results revealed that the preform structure and precursor can influence the oxidation behavior of c/Sic-SiHfBcN composites by effecting its thermal conductivity in the thickness direction. The Hf-containing oxide layer formed during ultra-high temperature oxidation test can effectively protect the internal carbon fibers from being oxidized. Linear ablation rate of c/Sic-SiHfBcN composites was more than an order of magnitude lower than that of other reported c/ Siccomposites, indicating an enhanced ablation resistance of the c/Sic-SiHfBcN composites.
When the global navigation satellite system (GNSS) is used for positioning in harsh environments with high occlusion and strong reflection, the signals are easily reflected, diffracted, or even blocked, which can lead...
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When the global navigation satellite system (GNSS) is used for positioning in harsh environments with high occlusion and strong reflection, the signals are easily reflected, diffracted, or even blocked, which can lead to multipath and non-line-of-sight (NLOS) errors. Existing stochastic models do not fully consider the significant unmodeled errors, such as multipath and NLOS, in specific scenarios such as canyons. This paper systematically establishes the carrier-to-noise ratio (c/N-0) template functions of the low-cost receiver for the first time and proposes an elevation stochastic model constrained by c/N-0 (elevation-c/N-0 model) by combining the two indicators (elevation angle and c/N-0) with the idea of robust estimation. Then, real-time kinematic positioning (RTK) experiments are conducted to verify the effectiveness of the new model, and both static monitoring and urban kinematic situations are included. The results showed that: (a) in the static data, the average ambiguity fixed rate of the elevation-c/N-0 model is 95.79%, which is 10.05%, 15.74%, and 12.57% higher than that of the equal-weight, elevation-based, and c/N-0-based stochastic models, respectively. At the same time, only the new model consistently meets centimeter-level accuracy requirements in harsh environments. (b) In the kinematic data, compared with the three traditional stochastic models, the ambiguity fixed rate of the elevation-c/N-0 stochastic model is increased by 58.33%, 19.79%, and 28.13%, respectively. The motion trajectory calculated by the elevation-c/N-0 model is the smoothest out of all the models. In conclusion, compared with the traditional stochastic models, the elevation-c/N-0 stochastic model is more applicable to both static and kinematic measurements in harsh environments. It can effectively mitigate the adverse effects of errors such as multipath and NLOS, increase the ambiguity fixed rate, and improve the positioning reliability to a certain extent, hence the proposed m
Most animal model studies of autism spectrum disorders (ASD) were performed in males. Thus, little is known about the mechanisms underlying disease progression in females. Here, we searched for potential influences of...
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Most animal model studies of autism spectrum disorders (ASD) were performed in males. Thus, little is known about the mechanisms underlying disease progression in females. Here, we searched for potential influences of sex and environment on gestational valproic acid-induced behavioral abnormalities using hippocampal-dependent tasks, and on number and morphometry of microglia of the molecular layer of the dentate gyrus (Mol-DG). We compared male and females BALB/ccontrol mice with BALB/c mice gestationally exposed to VPA with regards to exploratory activity and risk assessment in novel environments. Pregnant females and males on gestational day 12.5 received VPA in saline (600 mg/kg body weight) or an equal volume of saline by gavage. After weaning, female and male offspring were housed separately either in standard laboratory cages (SE) or enriched cages (EE). At 5 months of age, these mice underwent behavioral testing and had their brains processed for microglia IBA1 immunolabeling. compared with control mice, VPA-exposed mice exhibited abnormal behavior in exploring novel environments and assessing risk, and these effects were significantly greater in females than in males and less intense among mice from enriched cages. Three-way ANOVA revealed that environment, sex and valproic acid conditions interacted and altered the behavior results. Microglia number and volume of the Mol-DG were significantly higher in VPA-exposed groups raised in standard cages. The results of counting the intersects of microglia branching on Sholl's circles analyzed with permutational MANOVA, demonstrated that in comparison with males, there was a greater reduction in the number of intersections in females raised in standard cages. These findings suggest that the increased microglia and morphological changes might be associated with behavioral dysfunction in ASD. Moreover, the somatomotor and cognitive stimulation of environmental enrichment started at weaning may be beneficial for reduc
corynebacterium pseudotuberculosisis a pathogenic bacterium with great veterinary and economic importance. It is classified into two biovars:ovis, nitrate-negative, that causes lymphadenitis in small ruminants andequi...
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corynebacterium pseudotuberculosisis a pathogenic bacterium with great veterinary and economic importance. It is classified into two biovars:ovis, nitrate-negative, that causes lymphadenitis in small ruminants andequi, nitrate-positive, causing ulcerative lymphangitis in equines. With the explosive growth of available genomes of several strains, pan-genome analysis has opened new opportunities for understanding the dynamics and evolution ofc. pseudotuberculosis. However, few pan-genomic studies have compared *** studies have considered a reduced number of strains and compared entire genomes. Here we conducted an original pan-genome analysis based on protein sequences and their functional domains. We considered 53 c. pseudotuberculosisstrains from both biovars isolated from different hosts and countries. We have analysed conserved domains, common domains more frequently found in each biovar and biovar-specific (unique) domains. Our results demonstrated that biovarequiis more variable;there is a significant difference in the number of proteins per strains, probably indicating the occurrence of more gene loss/gain events. Moreover, strains of biovarequipresented a higher number of biovar-specific domains, 77 against only eight in biovarovis, most of them are associated with virulence mechanisms. With this domain analysis, we have identified functional differences among strains of biovarsovisandequithat could be related to niche-adaptation and probably help to better understanding mechanisms of virulence and pathogenesis. The distribution patterns of functional domains identified in this work might have impacts on bacterial physiology and lifestyle, encouraging the development of new diagnoses, vaccines, and treatments forc. pseudotuberculosisdiseases. communicated by Ramaswamy H. Sarma
The composition of comets hold clues about the early stages of the formation and evolution of the Solar System. Being the brightest comet observed in the northern hemisphere since the passage of comet c/1995 O1 (Hale-...
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The composition of comets hold clues about the early stages of the formation and evolution of the Solar System. Being the brightest comet observed in the northern hemisphere since the passage of comet c/1995 O1 (Hale-Bopp) in 1997, comet c/2020 F3 (NEOWISE) represents an interesting target for studying its coma composition and the chemical inventory of its *** aim to estimate the production rate (mol/s) for the chemical species identified in the coma. By comparing with other comets, we aim to assess whether this comet is typical or peculiar, and investigate any distinctive *** high resolution (R = 115000) spectra of c/2020 F3 at 0.72 AU from the Sun obtained with the HARPS-N instrument at the TNG, we measured the flux of selected c2, cN, c3, NH3 and O(1D) bands and emission lines, that were converted to production rates (Q) through the Haser formalism. From O(1D) we derive the production rate of water molecules. These values are then normalized with respect to cN and water production rates and compared with results from other spectroscopic *** estimate production rates Q(cN) = (1.55 +/- 0.39) center dot 1026 mol/s, Q(c2) = (1.76 +/- 0.32) center dot 1026 mol/s, Q(c3) = (0.32 +/- 0.12) center dot 1026, Q(H2O) = (3481.32 +/- 3.48) center dot 1026 mol/s and Q(NH2) = (10.58 +/- 3.64) center dot 1026 mol/s. With respect to water, we find relatively lower (by a factor of 4 -5) cN and c2 mixing ratios and a relatively high NH2 mixing ratios than other comets, especially for heliocentric distances below 1 *** calculated production rates and their ratios highlight discrepancies in the sublimation of comet c/2020 F3 with respect to Solar System comets and are consistent with the presence of a nucleus with a heterogeneous composition, already proposed in literature.
Antibiotic monitoring remains vital to ensure human health and safety in the environment and foods. As the most popular detection method, photoelectrochemical (PEc) sensor can achieve rapid and accurate detection of a...
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Antibiotic monitoring remains vital to ensure human health and safety in the environment and foods. As the most popular detection method, photoelectrochemical (PEc) sensor can achieve rapid and accurate detection of antibiotics with the advantages of high sensitivity, easy-to-preparation process, as well as high selectivity. Herein, an extremely-efficient visible-light responsible ZnO/c nanocomposite was prepared and combined with acetylene black (as an enhanced conductive matrix), and the electron migration efficiency was greatly accelerated. Meanwhile, a molecularly imprinted polymer obtained by electrical agglomeration was conjugated as a specific recognizing site for target. Furthermore, the as-prepared rMIP-PEc sensor showed a low detection limit (8.75 pmol L-1, S/N = 3) in a wide linear detection range of 0.01-1000 nmol L-1 for oxytetracycline (OTc), with excellent selectivity and long-term stability. Our work shed light on applying c-doped ZnO semiconductor and molecularly imprinted polymer as photoelectric active sensing materials for rapid and accurate analysis of antibiotics in foods and environment.
A hexanucleotide repeat expansion in the c9orf72 gene is the most common cause of inherited amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Unconventional translation of the c9orf72 repeat produ...
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A hexanucleotide repeat expansion in the c9orf72 gene is the most common cause of inherited amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Unconventional translation of the c9orf72 repeat produces dipeptide repeat proteins (DPRs). Previously, we showed that the DPRs PR50 and GR50 are highly toxic when expressed in caenorhabditis elegans , and this toxicity depends on nuclear localization of the DPR. In an unbiased genome-wide RNA interference (RNAi) screen for suppressors of PR50 toxicity, we identified 12 genes that consistently suppressed either the developmental arrest and/or paralysis phenotype evoked by PR50 expression. All of these genes have vertebrate homologs, and 7 of 12 contain predicted nuclear localization signals. One of these genes was spop-1 , the c. elegans homolog of SPOP , a nuclear localized E3 ubiquitin ligase adaptor only found in metazoans. SPOP is also required for GR50 toxicity and functions in a genetic pathway that includes cul-3 , which is the canonical E3 ligase partner for SPOP. Genetic or pharmacological inhibition of SPOP in mammalian primary spinal cord motor neurons suppressed DPR toxicity without affecting DPR expression levels. Finally, we find that knockdown of bromodomain proteins in both c. elegans and mammalian neurons, which are known SPOP ubiquitination targets, suppresses the protective effect of SPOP inhibition. Together, these data suggest a model in which SPOP promotes the DPR-dependent ubiquitination and degradation of BRD proteins. We speculate the pharmacological manipulation of this pathway, which is currently underway for multiple cancer subtypes, could also represent an entry point for therapeutic intervention to treat c9orf72 FTD/ALS.
Transition metal sulfides are often used as heterogeneous catalysts to activate peroxymonosulfate (PMS), but insufficient active sites on catalysts surface limited the further application. Herein, a porous carbon-base...
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Transition metal sulfides are often used as heterogeneous catalysts to activate peroxymonosulfate (PMS), but insufficient active sites on catalysts surface limited the further application. Herein, a porous carbon-based copper sulfide (cuSx/c) nanosphere with plentiful sulfur vacancies was obtained and exhibited excellent catalytic activity for degrading pollutants (97.9 % for Rhodamine B (RhB) degradation within 6 min) in PMS system, which was significantly higher than that of cuS and cuSx (7.1 % and 13.8 %). The high catalytic performance of cuSx/c was mainly attributed to the existence of plentiful sulfur vacancies and the special porous morphology, thereby more cu+/cu2+ exposed on the cuSx/c surface, and further provided more active sites for the activation of PMS. This research provides a new strategy to construct high performance transition metal sulfides catalysts with sufficient sulfur vacancies for activating PMS.
In this study, based on an ocean data assimilation system for the coupled climate model cAS-ESM-c, how to reasonably assimilate altimetry data are explored. In sea surface height (SSH) assimilations, the mean dynamic ...
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In this study, based on an ocean data assimilation system for the coupled climate model cAS-ESM-c, how to reasonably assimilate altimetry data are explored. In sea surface height (SSH) assimilations, the mean dynamic topography (MDT) is an important factor that can coordinate the observed sea level anomalies with the modeled SSH. The SSH assimilation results are first compared through assimilation experiments using three different MDTs, including the observed reference height, the MDT from model control run, and the MDT from the assimilation experiment in cAS-ESM-c, with the climatological World Ocean Atlas (WOA) temperature assimilated into the coupled model. The results show that the third one can significantly improve the ability of the ocean data assimilation system to assimilate the SSH observations. Using this MDT, the SSH assimilation scheme of the ocean data assimilation system was established for the cAS-ESM-c, and a long-term SSH assimilation experiment from 1994 to 2017 was carried out. The results show that the SSH assimilation performs much better than the SST assimilation in reproducing the ocean states and seasonal-interannual variability. The improvements of SSH assimilation compared with SST assimilation may be due to the different properties of the two ocean variables. While SST is a thermodynamic variable used to evaluate the thermal condition of the ocean surface layer, SSH is a dynamic variable linked to the dynamical information of the whole ocean layer. Thus, SSH assimilation can constrain the ocean model with observed dynamic information, which is more important to the state estimation and temporal evolution of the ocean.
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