395 research outputs found
An Empirical Study of Customer Satisfaction and Loyalty on Health Websites
Numerous health websites are developing rapidly in China and the competition is fierce between these websites. In order to win the competition, the websites operators need to satisfy their customers to attain more market shares. But few attention has been paid to factors affecting customer satisfaction and loyalty on these websites. As a result, the paper aims to empirically explore the factors affecting customer satisfaction and loyalty on health websites based on perceived service quality (responsiveness, empathy and reliability), perceived risk (financial risk and time risk) and trust, and then to propose some targeted measures. A survey was conducted to collect data by means of questionnaires, and a total of 231 usable responses were gathered. Then the hypothesis model was tested using the Structural Equation Modeling(SEM). Results revealed that responsiveness, empathy, time risk and trust had significant impacts on customer satisfaction, whereas reliability and financial risk showed no effects on customer satisfaction. In addition, customer satisfaction and trust significantly influenced customer loyalty. The implications and limitations were discussed
NLP From Scratch Without Large-Scale Pretraining: A Simple and Efficient Framework
Pretrained language models have become the standard approach for many NLP
tasks due to strong performance, but they are very expensive to train. We
propose a simple and efficient learning framework, TLM, that does not rely on
large-scale pretraining. Given some labeled task data and a large general
corpus, TLM uses task data as queries to retrieve a tiny subset of the general
corpus and jointly optimizes the task objective and the language modeling
objective from scratch. On eight classification datasets in four domains, TLM
achieves results better than or similar to pretrained language models (e.g.,
RoBERTa-Large) while reducing the training FLOPs by two orders of magnitude.
With high accuracy and efficiency, we hope TLM will contribute to democratizing
NLP and expediting its development.Comment: 14 pages, 5 figure
2'-Fucosyllactose Remits Colitis-Induced Liver Oxygen Stress through the Gut-Liver-Metabolites Axis.
peer reviewedLiver oxygen stress is one of the main extraintestinal manifestations of colitis and 5% of cases develop into a further liver injury and metabolic disease. 2′-fucosyllactose (2′-FL), a main member of human milk oligosaccharides (HMOs), has been found to exert efficient impacts on remitting colitis. However, whether 2′-FL exerts the function to alleviate colitis-induced liver injury and how 2′-FL influences the metabolism via regulating gut microbiota remain unknown. Herein, in our study, liver oxygen stress was measured by measuring liver weight and oxygen-stress-related indicators. Then, 16S full-length sequencing analysis and non-target metabolome in feces were performed to evaluate the overall responses of metabolites and intestinal bacteria after being treated with 2′-FL (400 mg/kg b.w.) in colitis mice. The results showed that, compared with the control group, the liver weight of colitis mice was significantly decreased by 18.30% (p < 0.05). After 2′-FL treatment, the liver weight was significantly increased by 12.65% compared with colitis mice (p < 0.05). Meanwhile, they exhibited higher levels of oxidation in liver tissue with decreasing total antioxidant capacity (T-AOC) (decreased by 17.15%) and glutathione (GSH) levels (dropped by 22.68%) and an increasing malondialdehyde (MDA) level (increased by 36.24%), and 2′-FL treatment could reverse those tendencies. Full-length 16S rRNA sequencing revealed that there were 39 species/genera differentially enriched in the control, dextran sulphate sodium (DSS), and DSS + 2′-FL groups. After treatment with 2′-FL, the intestinal metabolic patterns, especially glycometabolism and the lipid-metabolism-related process, in DSS mice were strikingly altered with 33 metabolites significantly down-regulated and 26 metabolites up-regulated. Further analysis found DSS induced a 40.01%, 41.12%, 43.81%, and 39.86% decline in acetic acid, propionic acid, butyric acid, and total short chain fatty acids (SCFAs) in colitis mice (all p < 0.05), respectively, while these were up-regulated to different degrees in the DSS + 2′-FL group. By co-analyzing the data of gut microbiota and metabolites, glycometabolism and lipid-metabolism-associated metabolites exhibited strong positive/negative relationships with Akkermansia_muciniphila (all p < 0.01) and Paraprevotella spp. (all p < 0.01), suggesting that the two species might play crucial roles in the process of 2′-FL alleviating colitis-induced liver oxygen stress. In conclusion, in the gut−liver−microbiotas axis, 2′-FL mediated in glucose and lipid-related metabolism and alleviated liver oxygen stress via regulating gut microbiota in the DSS-induced colitis model. The above results provide a new perspective to understand the probiotic function of 2′-FL
High yield expression of an AHL-lactonase from Bacillus sp. B546 in Pichia pastoris and its application to reduce Aeromonas hydrophila mortality in aquaculture
<p>Abstract</p> <p>Background</p> <p><it>Aeromonas hydrophila </it>is a serious pathogen and can cause hemorrhagic septicemia in fish. To control this disease, antibiotics and chemicals are widely used which can consequently result in "superbugs" and chemical accumulation in the food chain. Though vaccine against <it>A. hydrophila </it>is available, its use is limited due to multiple serotypes of this pathogen and problems of safety and efficacy. Another problem with vaccination is the ability to apply it to small fish especially in high numbers. In this study, we tried a new way to attenuate the <it>A. hydrophila </it>infection by using a quorum quenching strategy with a recombinant AHL-lactonase expressed in <it>Pichia pastoris</it>.</p> <p>Results</p> <p>The AHL-lactonase (AiiA<sub>B546</sub>) from <it>Bacillus </it>sp. B546 was produced extracellularly in <it>P. pastoris </it>with a yield of 3,558.4 ± 81.3 U/mL in a 3.7-L fermenter when using 3-oxo-C8-HSL as the substrate. After purification with a HiTrap Q Sepharose column, the recombinant homogenous protein showed a band of 33.6 kDa on SDS-PAGE, higher than the calculated molecular mass (28.14 kDa). Deglycosylation of AiiA<sub>B546 </sub>with Endo H confirmed the occurrence of <it>N</it>-glycosylation. The purified recombinant AiiA<sub>B546 </sub>showed optimal activity at pH 8.0 and 20°C, exhibited excellent stability at pH 8.0-12.0 and thermal stability at 70°C, was firstly confirmed to be significantly protease-resistant, and had wide substrate specificity. In application test, when co-injected with A. <it>hydrophila </it>in common carp, recombinant AiiA<sub>B546 </sub>decreased the mortality rate and delayed the mortality time of fish.</p> <p>Conclusions</p> <p>Our results not only indicate the possibility of mass-production of AHL-lactonase at low cost, but also open up a promising foreground of application of AHL-lactonase in fish to control <it>A. hydrophila </it>disease by regulating its virulence. To our knowledge, this is the first report on heterologous expression of AHL-lactonase in <it>P. pastoris </it>and attenuating <it>A. hydrophila </it>virulence by co-injection with AHL-lactonase.</p
Distribution of Side Abutment Stress in Roadway Subjected to Dynamic Pressure and Its Engineering Application
The borehole stress-meter was employed in this study to investigate the distribution of the side abutment stress in roadway subjected to dynamic pressure. The results demonstrate that the side abutment stress of the mining roadway reaches a peak value when the distance to the gob is 8 m and the distribution curve of the side abutment stress can be divided into three zones: stress rising zone, stress stabilizing zone, and stress decreasing zone. Further numerical investigation was carried out to study the effect of the coal mass strength, coal seam depth, immediate roof strength, and thickness on the distribution of the side abutment stress. Based on the research results, we determined the reasonable position of the mining roadway and the optimal width of the barrier pillar. The engineering application demonstrates that the retention of the barrier pillar with a width of 5 m along the gob as the haulage roadway for the next panel is feasible, which delivers favorable technological and economic benefits
Chemical differences among collapsing low-mass protostellar cores
Organic features lead to two distinct types of Class 0/I low-mass protostars:
hot corino sources, and warm carbon-chain chemistry (WCCC) sources. Some
observations suggest that the chemical variations between WCCC sources and hot
corino sources are associated with local environments, as well as the
luminosity of protostars. We conducted gas-grain chemical simulation in
collapsing protostellar cores, and found that the fiducial model predicts
abundant carbon-chain molecules and COMs, and reproduces WCCC and hot corino
chemistry in the hybrid source L483. By changing values of some physical
parameters, including the visual extinction of ambient clouds (), the cosmic-ray ionization rate (), the maximum temperature
during the warm-up phase (), and the contraction timescale of
protostars (), we found that UV photons and cosmic rays can boost
WCCC features by accelerating the dissociation of CO and CH molecules. On
the other hand, UV photons can weaken the hot corino chemistry by
photodissociation reactions, while the dependence of hot corino chemistry on
cosmic rays is relatively complex. The does not affect WCCC
features, while it can influence hot corino chemistry by changing the effective
duration of two-body surface reactions for most COMs. The long
can boost WCCC and hot corino chemistry, by prolonging the effective duration
of WCCC reactions in the gas phase and surface formation reactions for COMs,
respectively. Subsequently, we ran a model with different physical parameters
to reproduce scarce COMs in prototypical WCCC sources. The scarcity of COMs in
prototypical WCCC sources can be explained by insufficient dust temperature in
the inner envelopes to activate hot corino chemistry. Meanwhile, the High
and the long favors the explanation for scarce COMs in
these sources.Comment: Accepted for publication in A&A, 18 pages, 10 figure
A novel MIPgene mutation associated with autosomal dominant congenital cataracts in a Chinese family
BACKGROUND: The major intrinsic protein gene (MIP), also known as MIP26 or AQP0, is a member of the water-transporting aquaporin family, which plays a critical role in the maintenance of lifelong lens transparency. To date, several mutations in MIP (OMIM 154050) have been linked to hereditary cataracts in humans. However, more pathogenic mutations remain to be identified. In this study, we describe a four-generation Chinese family with a nonsense mutation in MIP associated with an autosomal dominant congenital cataract (ADCC), thus expanding the mutational spectrum of this gene. METHODS: A large four-generation Chinese family affected with typical Y-suture cataracts combined with punctuate cortical opacities and 100 ethnically matched controls were recruited. Genomic DNA was extracted from peripheral blood leukocytes to analyze congenital cataract-related candidate genes. Effects of the sequence change on the structure and function of proteins were predicted by bioinformatics analysis. RESULTS: Direct sequencing of MIP in all affected members revealed a heterozygous nucleotide exchange c.337C>T predicting an arginine to a stop codon exchange (p.R113X). The substitution co-segregated well in all the affected individuals in the family and was not found in unaffected members or in the 100 unrelated healthy controls. Bioinformatics analysis predicted that the mutation affects the secondary structure and function of the MIP protein. CONCLUSIONS: We identified a novel mutation of MIP (p.R113X) in a Chinese cataract family. This is the first nonsense mutation of MIP identified thus far. This novel mutation is also the first disease-causing mutation located in the loop C domain of MIP. The results add to the list of mutations of the MIP linked to cataracts
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