110 research outputs found
Identification of Unequally Represented Founder Viruses Among Tissues in Very Early SIV Rectal Transmission
Characterizing the transmitted/founder (T/F) viruses of multi-variant SIV infection may shed new light on the understanding of mucosal transmission.We intrarectally inoculated six Chinese rhesus macaques with a single high dose of SIVmac251 (3.1 × 104 TCID50) and obtained 985 full-length env sequences from multiple tissues at 6 and 10 days post-infection by single genome amplification (SGA). All 6 monkeys were infected with a range of 2 to 8 T/F viruses and the dominant variants from the inoculum were still dominant in different tissues from each monkey. Interestingly, our data showed that a cluster of rare T/F viruses was unequally represented in different tissues. This cluster of rare T/F viruses phylogenetically related to the non-dominant SIV variants in the inoculum and was not detected in any rectum tissues, but could be identified in the descending colon, jejunum, spleen, or plasma. In 2 out of 6 macaques, identical SIVmac251 variants belonging to this cluster were detected simultaneously in descending colon/jejunum and the inoculum.We also demonstrated that the average CG dinucleotide frequency of these rare T/F viruses found in tissues, as well as non-dominant variants in the inoculum, was significantly higher than the dominant T/F viruses in tissues and the inoculum. Collectively, these findings suggest that descending colon/jejunum might be more susceptible than rectum to SIV in the very early phase of infection. And host CG suppression, which was previously shown to inhibit HIV replication in vitro, may also contribute to the bottleneck selection during in vivo transmission
Characterization of isoprene-derived secondary organic aerosols at a rural site in North China Plain with implications for anthropogenic pollution effects
Isoprene is the most abundant non-methane volatile organic compound (VOC) and the largest contributor to secondary organic aerosol (SOA) burden on a global scale. In order to examine the influence of high concentrations of anthropogenic pollutants on isoprene-derived SOA (SOA(i)) formation, summertime PM2.5 filter samples were collected with a three-hour sampling interval at a rural site in the North China Plain (NCP), and determined for SOA(i) tracers and other chemical species. RO2+NO pathway derived 2-methylglyceric acid presented a relatively higher contribution to the SOA, due to the high-NOx (similar to 20 ppb) conditions in the NCP that suppressed the reactive uptake of RO2+HO2 reaction derived isoprene epoxydiols. Compared to particle acidity and water content, sulfate plays a dominant role in the heterogeneous formation process of SOA(i). Diurnal variation and correlation of 2-methyltetrols with ozone suggested an important effect of isoprene ozonolysis on SOA(i) formation. SOA(i) increased linearly with levoglucosan during June 10-18, which can be attributed to an increasing emission of isoprene caused by the field burning of wheat straw and a favorable aqueous SOA formation during the aging process of the biomass burning plume. Our results suggested that isoprene oxidation is highly influenced by intensive anthropogenic activities in the NCP
Immunomodulatory roles of metalloproteinases in rheumatoid arthritis
Rheumatoid arthritis (RA) is a chronic, autoimmune pathology characterized by persistent synovial inflammation and gradually advancing bone destruction. Matrix metalloproteinases (MMPs), as a family of zinc-containing enzymes, have been found to play an important role in degradation and remodeling of extracellular matrix (ECM). MMPs participate in processes of cell proliferation, migration, inflammation, and cell metabolism. A growing number of persons have paid attention to their function in inflammatory and immune diseases. In this review, the details of regulation of MMPs expression and its expression in RA are summarized. The role of MMPs in ECM remodeling, angiogenesis, oxidative and nitrosative stress, cell migration and invasion, cytokine and chemokine production, PANoptosis and bone destruction in RA disease are discussed. Additionally, the review summarizes clinical trials targeting MMPs in inflammatory disease and discusses the potential of MMP inhibition in the therapeutic context of RA. MMPs may serve as biomarkers for drug response, pathology stratification, and precision medicine to improve clinical management of rheumatoid arthritis
Microbiome-derived bile acids contribute to elevated antigenic response and bone erosion in rheumatoid arthritis
Rheumatoid arthritis (RA) is a chronic, disabling and incurable autoimmune
disease. It has been widely recognized that gut microbial dysbiosis is an
important contributor to the pathogenesis of RA, although distinct alterations
in microbiota have been associated with this disease. Yet, the metabolites that
mediate the impacts of the gut microbiome on RA are less well understood. Here,
with microbial profiling and non-targeted metabolomics, we revealed profound
yet diverse perturbation of the gut microbiome and metabolome in RA patients in
a discovery set. In the Bacteroides-dominated RA patients, differentiation of
gut microbiome resulted in distinct bile acid profiles compared to healthy
subjects. Predominated Bacteroides species expressing BSH and 7a-HSDH
increased, leading to elevated secondary bile acid production in this subgroup
of RA patients. Reduced serum fibroblast growth factor-19 and dysregulated bile
acids were evidence of impaired farnesoid X receptor-mediated signaling in the
patients. This gut microbiota-bile acid axis was correlated to ACPA. The
patients from the validation sets demonstrated that ACPA-positive patients have
more abundant bacteria expressing BSH and 7a-HSDH but less Clostridium scindens
expressing 7a-dehydroxylation enzymes, together with dysregulated microbial
bile acid metabolism and more severe bone erosion than ACPA-negative ones.
Mediation analyses revealed putative causal relationships between the gut
microbiome, bile acids, and ACPA-positive RA, supporting a potential causal
effect of Bacteroides species in increasing levels of ACPA and bone erosion
mediated via disturbing bile acid metabolism. These results provide insights
into the role of gut dysbiosis in RA in a manifestation-specific manner, as
well as the functions of bile acids in this gut-joint axis, which may be a
potential intervention target for precisely controlling RA conditions.Comment: 38 pages, 6 figure
Persistent sulfate formation from London Fog to Chinese haze
Sulfate aerosols exert profound impacts on human and ecosystem health, weather, and climate, but their formation mechanism remains uncertain. Atmospheric models consistently underpredict sulfate levels under diverse environmental conditions. From atmospheric measurements in two Chinese megacities and complementary laboratory experiments, we show that the aqueous oxidation of SO2 by NO2 is key to efficient sulfate formation but is only feasible under two atmospheric conditions: on fine aerosols with high relative humidity and NH3 neutralization or under cloud conditions. Under polluted environments, this SO2 oxidation process leads to large sulfate production rates and promotes formation of nitrate and organic matter on aqueous particles, exacerbating severe haze development. Effective haze mitigation is achievable by intervening in the sulfate formation process with enforced NH3 and NO2 control measures. In addition to explaining the polluted episodes currently occurring in China and during the 1952 London Fog, this sulfate production mechanism is widespread, and our results suggest a way to tackle this growing problem in China and much of the developing world
Articulatory-to-Acoustic Conversion of Mandarin Emotional Speech Based on PSO-LSSVM
The production of emotional speech is determined by the movement of the speaker’s tongue, lips, and jaw. In order to combine articulatory data and acoustic data of speakers, articulatory-to-acoustic conversion of emotional speech has been studied. In this paper, parameters of LSSVM model have been optimized using the PSO method, and the optimized PSO-LSSVM model was applied to the articulatory-to-acoustic conversion. The root mean square error (RMSE) and mean Mel-cepstral distortion (MMCD) have been used to evaluate the results of conversion; the evaluated result illustrates that MMCD of MFCC is 1.508 dB, and RMSE of the second formant (F2) is 25.10 Hz. The results of this research can be further applied to the feature fusion of emotion speech recognition to improve the accuracy of emotion recognition
Identification of Unequally Represented Founder Viruses Among Tissues in Very Early SIV Rectal Transmission
Characterizing the transmitted/founder (T/F) viruses of multi-variant SIV infection may shed new light on the understanding of mucosal transmission. We intrarectally inoculated six Chinese rhesus macaques with a single high dose of SIVmac251 (3.1 × 104 TCID50) and obtained 985 full-length env sequences from multiple tissues at 6 and 10 days post-infection by single genome amplification (SGA). All 6 monkeys were infected with a range of 2 to 8 T/F viruses and the dominant variants from the inoculum were still dominant in different tissues from each monkey. Interestingly, our data showed that a cluster of rare T/F viruses was unequally represented in different tissues. This cluster of rare T/F viruses phylogenetically related to the non-dominant SIV variants in the inoculum and was not detected in any rectum tissues, but could be identified in the descending colon, jejunum, spleen, or plasma. In 2 out of 6 macaques, identical SIVmac251 variants belonging to this cluster were detected simultaneously in descending colon/jejunum and the inoculum. We also demonstrated that the average CG dinucleotide frequency of these rare T/F viruses found in tissues, as well as non-dominant variants in the inoculum, was significantly higher than the dominant T/F viruses in tissues and the inoculum. Collectively, these findings suggest that descending colon/jejunum might be more susceptible than rectum to SIV in the very early phase of infection. And host CG suppression, which was previously shown to inhibit HIV replication in vitro, may also contribute to the bottleneck selection during in vivo transmission
A Systematic Study on DNA Barcoding of Medicinally Important Genus <i>Epimedium</i> L. (Berberidaceae)
Genus Epimedium consists of approximately 50 species in China, and more than half of them possess medicinal properties. The high similarity of species’ morphological characteristics complicates the identification accuracy, leading to potential risks in herbal efficacy and medical safety. In this study, we tested the applicability of four single loci, namely, rbcL, psbA-trnH, internal transcribed spacer (ITS), and ITS2, and their combinations as DNA barcodes to identify 37 Epimedium species on the basis of the analyses, including the success rates of PCR amplifications and sequencing, specific genetic divergence, distance-based method, and character-based method. Among them, character-based method showed the best applicability for identifying Epimedium species. As for the DNA barcodes, psbA-trnH showed the best performance among the four single loci with nine species being correctly differentiated. Moreover, psbA-trnH + ITS and psbA-trnH + ITS + rbcL exhibited the highest identification ability among all the multilocus combinations, and 17 species, of which 12 are medicinally used, could be efficiently discriminated. The DNA barcode data set developed in our study contributes valuable information to Chinese resources of Epimedium. It provides a new means for discrimination of the species within this medicinally important genus, thus guaranteeing correct and safe usage of Herba Epimedii
T-S Fuzzy Model-Based Fault Detection for Continuous Stirring Tank Reactor
Continuous stirring tank reactors are widely used in the chemical production process, which is always accompanied by nonlinearity, time delay, and uncertainty. Considering the characteristic of the actual reaction of the continuous stirring tank reactors, the fault detection problem is studied in terms of the T-S fuzzy model. Through a fault detection filter performance analysis, the sufficient condition for the filtering error dynamics is obtained, which meets the exponential stability in the mean square sense and the given performance requirements. The design of the fault detection filter is transformed into one that settles the convex optimization issue of linear matrix inequality. Numerical analysis shows the effectiveness of this scheme
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