Insights into microbiota community dynamics and flavor development mechanism during golden pomfret(Trachinotus ovatus)fermentation based on single-molecule real-time sequencing and molecular networking analysis

Popular fermented golden pomfret(Trachinotus ovatus)is prepared via spontaneous fermentation;however,the mechanisms underlying the regulation of its flavor development remain unclear.This study shows the roles of the complex microbiota and the dynamic changes in microbial community and flavor compounds during fish fermentation.Single-molecule real-time sequencing and molecular networking analysis revealed the correlations among different microbial genera and the relationships between microbial taxa and volatile compounds.Mechanisms underlying flavor development were also elucidated via KEGG based functional annotations.Clostridium,Shewanella,and Staphylococcus were the dominant microbial genera.Forty-nine volatile compounds were detected in the fermented fish samples,with thirteen identified as characteristic volatile compounds(ROAV>1).Volatile profiles resulted from the interactions among the microorganisms and derived enzymes,with the main metabolic pathways being amino acid biosynthesis/metabolism,carbon metabolism,and glycolysis/gluconeogenesis.This study demonstrated the approaches for distinguishing key microbiota associated with volatile compounds and monitoring the industrial production of high-quality fermented fish products.

Analysis of quality-related proteins in golden pompano(Trachinotus ovatus)fillets with modified atmosphere packaging under superchilling storage

Here,we aimed to study the changes in proteome of golden pompano fillets during post-mortem storage.Tandem mass tags(TMT)-labeled quantitative proteomic strategy was applied to investigate the relationships between protein changes and quality characteristics of modified atmosphere packaging(MAP)fillets during superchilling(-3°C)storage.Scanning electron microscopy was used to show that the muscle histology microstructure of fillets was damaged to varying degrees,and low-field nuclear magnetic resonance was used to find that the immobilized water and free water in the muscle of fillets changed significantly.Total sulfhydryl content,TCA-soluble peptides and Ca2+-ATPase activity also showed that the fillet protein had a deterioration by oxidation and denaturation.The Fresh(FS),MAP,and air packaging(AP)groups were set.Total of 150 proteins were identified as differential abundant proteins(DAPs)in MAP/FS,while 209 DAPs were in AP/FS group.The KEGG pathway analysis indicated that most DAPs were involved in binding proteins and protein turnover.Correlation analysis found that 52 DAPs were correlated with quality traits.Among them,8 highly correlated DAPs are expected to be used as potential quality markers for protein oxidation and water-holding capacity.These results provide a further understanding of the muscle deterioration mechanism of packaging golden pompano fillets during superchilling.

OsNPF3.1,a member of the NRT1/PTR family,increases nitrogen use efficiency and biomass production in rice

The overuse of nitrogen(N)fertilizer in fields has increased production costs and raised environmental concerns.Increasing the N use efficiency(NUE)of rice varieties is crucial for sustainable agriculture.Here we report the cloning and characterization of OsNPF3.1,a gene that controls rice NUE.An amino acid mutation in the OsNPF3.1 coding region caused different NUEs in wild and cultivated rice.OsNPF3.1,which is expressed mainly in the aerial parts of rice,also affects rice plant height,heading date,and thousand-grain weight.The OsNPF3.1 protein is located in the plasma membrane.When OsNPF3.1 was subjected to artificial selection,two naturally varying loci were associated with NUE,of which OsNPF3.1Chr6_8741040differed between indica and japonica rice.OsNPF3.1 can be used as a new target gene for breeding rice varieties with high NUE.

Novel insight into the formation and inhibition mechanism of dipeptidyl peptidase-Ⅳ inhibitory peptides from fermented mandarin fish(Chouguiyu)

Fermented foods are a potential source to produce novel dipeptidyl peptidase-IV inhibitory peptides(D4IPs).In this study,the fermented mandarin fish(Chouguiyu)was used to screen D4IPs and their formation mechanism was studied by metagenomics and peptidomics.A total of 400 D4IPs with DPP-IV inhibition structure and high hydrophobicity were identified.The correlation network map showed that Lactococcus,Bacillus,Lysobacter,Pelagivirga,Kocuria,Escherichia,Streptococcus,and Peptostreptococcus were significantly correlated with the most D4IPs.Four stable D4IPs,including KAGARALTDAETAT,GEKVDFDDIQK,VVDADEMYLKGK,and GQKDSYVGDEAQ were respectively from the precursor proteins parvalbumin,troponin,myosin,and actin,and were mainly formed by the hydrolysis of subtilisin(EC 3.4.21.62),aspartic proteinase(EC 3.4.23.1),thermolysin(EC 3.4.24.27),oligopeptidase B(EC 3.4.21.83),and proteinase P1(EC 3.4.21.96)from Bacillus,Kocuria,Lysobacter,Lactococcus,and Peptostreptococcus.The inhibition mainly resulted from the hydrogen bond and salt bridge between D4IPs and DPP-IV enzyme.This study provides important information on the proteases and related microbial strains to directionally prepare D4IPs in Chouguiyu.

Analysis of Combining OBE and CBL in Pharmacy Internship

Talent training has been emphasized in China’s national development.Training an excellent pharmaceutical professional has far-reaching significance for promoting rational use of drugs,ensuring safe drug use,and improving the quality and safety of medical treatment.The internship program is an important part of a pharmacy major that serves to develop students’practical skills.In this paper,we propose a combination of outcome-based education(OBE)and case-based learning(CBL)in pharmacy internships to promote critical thinking and independent learning among students and ensure the sustainable development of pharmacy education.

Genome-wide identification and characterization of the bHLH gene family in an ornamental woody plant Prunus mume

The basic helix-loop-helix(bHLH)transcription factor family is the second-largest family in plants,where it plays essential roles in development,and the responses to multiple abiotic and biotic stressors.However,little information is available about this gene family in Prunus mume,which is widely cultivated in East Asia as an ornamental fruit tree.Here,100 PmbHLH genes were identified,and their evolution and functions were explored in P.mume for the first time.The PmbHLH genes were classified into 21 subfamilies.The chromosomal distribution,physicochemical properties,bHLH domain,conserved motif,and intron/exon compositions were also analyzed.Furthermore,the evolutionary pattern,divergence time of the PmbHLH family,and genetic relationships among P.mume,Arabidopsis thaliana,and Prunus persica and Fragaria vesca of Rosaceae were explored.The functional prediction analysis of these PmbHLHs indicated that their functions varied,and included participating in the formation of organs and tissues,responding to stress,and the biosynthesis and metabolism of hormones and other secondary metabolites.Interestingly,expression analyses of PmbHLHs also revealed diverse expression patterns.Most of the PmbHLH genes were highly expressed in roots and stems,and a few were highly expressed in leaves,buds,and fruits,indicating tissue expression specificity.Eight PmbHLH genes,which were upregulated during low-temperature stress,may have critical roles in the response to cold stress.Ten PmbHLHs were differentially expressed between weeping and upright branches in a P.mume F_(1) population.These results shed light on the structure and evolution of the PmbHLH gene family,and lay a foundation for further functional studies of the bHLH genes.

Risk factors for myopia in Inner Mongolia medical students in China

Objective: The aim of the study was to investigate myopia and related factors in Inner Mongolia Medical Students, China. Methods: The survey employed a self-administered questionnaire. All medical students from the Inner Mongolia Medical University campus and those living and learning on campus were eligible. The questionnaire consisted of three sections: students’ basic information, attitude on myopia behavior, and myopia status of students. 6047 medical students completed the questionnaire. Results: A total of 6040 (90.5%) students aged 16 to 28 years (mean 21 ± 1.5 years) completed the questionnaire, of which 1772 (29.3%) were male and 4268 (70.6%) were female. The Mongolia of medical students had the lowest rate (64.3%) of myopia. The prevalence of myopia in Han nationality was highest (72.8%). Myopia occurred more frequently among students living in the city than in the rural. 76.4% urban and 66.6% rural students had myopia (p < 0.001). For myopia students it was established that 85.5% had begun to wear spectacles in middle school. Conclusion: A high myopia prevalence was demonstrated among medical students in the Inner Mongolia area of China. Our study’s findings could help health care professionals develop targeted myopia control policies for the population of students in Inner Mongolia of China and ensure the policies are more rational, useful, and effective.

Asymptotic Inference for the Weak Stationary Double AR(1) Model

An AR(1) model with ARCH(1) error structure is known as the first-order double autoregressive (DAR(1)) model. In this paper, a conditional likelihood based method is proposed to obtain inference for the two scalar parameters of interest of the DAR(1) model. Theoretically, the proposed method has rate of convergence O(n-3/2). Applying the proposed method to a real-life data set shows that the results obtained by the proposed method can be quite different from the results obtained by the existing methods. Results from Monte Carlo simulation studies illustrate the supreme accuracy of the proposed method even when the sample size is small.

Molecular dynamics simulation of thermal conductivity of silicone rubber

Silicone rubber is widely used as a kind of thermal interface material(TIM)in electronic devices.However few studies have been carried out on the thermal conductivity mechanism of silicone rubber.This paper investigates the thermal conductivity mechanism by non-equilibrium molecular dynamics(NEMD)in three aspects:chain length,morphology,and temperature.It is found that the effect of chain length on thermal conductivity varies with morphologies.In crystalline state where the chains are aligned,the thermal conductivity increases apparently with the length of the silicone-oxygen chain,the thermal conductivity of 79 nm-long crystalline silicone rubber could reach 1.49 W/(m·K).The thermal conductivity of amorphous silicone rubber is less affected by the chain length.The temperature dependence of thermal conductivity of silicone rubbers with different morphologies is trivial.The phonon density of states(DOS)is calculated and analyzed.The results indicate that crystalline silicone rubber with aligned orientation has more low frequency phonons,longer phonon MFP,and shorter conducting path,which contribute to a larger thermal conductivity.

The impact of academic stress on medical students attending college in the Inner Mongolia Area of China

The aim of this study was to examine whether student characteristics affect the risk of health conditions, and explore whether the degree of academic stress affects the level of distress. We surveyed medical students in the Inner Mongolia Medical College China using a questionnaire. A logistic regression analysis was used to ascertain factors associated with distress. The Wilcoxon Mann-Whitney test was used to determine the relationship between distress and different academic stress levels. Of the 6044 students completing questionnaires, 47.5% self-reported distressing body symptoms induced by academic stress. Chi square tests showed statistically significant associations between distress and gender, academic stress, and residence;feeling academic stress caused a more than 1.5 times risk of distress. Gender and academic stress were significantly associated with distress in non-conditional binary logistic regression models. Compared with male students, female students was more likely to feel distress. The Wilcoxon Mann-Whitney test also showed that the distress rate increased with academic stress and a dose-response relationship between the distress rate and stress level was found. The present study indicates that it is important to reduce academic stress and manage it in order that better outcomes be achieved in regard to distress, especially in females.

Effects of Different Selenium Fertilizer Types on Selenium Content and Quality of "Lingfeng" Grapes

[Objectives]This study was conducted to choose a selenium-rich foliar fertilizer suitable for the selenium-rich fruit and vegetable industry in Guangxi.[Methods]With "Lingfeng" wine grapes as test materials,such four kinds of selenium fertilizers as "Jufu Selenium"(JF),"Taishan Weed Fertilizer"(TS),"Zhongnong No.6"(ZN) and "Kangxibao"(KX) were used as exogenous selenium for the experiment of selenium-enriched grapes.[Results]The selenium contents in the grape fruit applied with the selenium fertilizers increased by 1.2-16.8 times compared with the control (CK),and JF and ZN had a better selenium-enriching effect and produced the fruit having the selenium contents reaching 75.85 and 45.79 μg/kg,respectively.Spraying selenium fertilizers can improve some quality indexes of grapes in that spraying JF on the leaves can significantly increase the total sugar content of the grapes while reducing the total acid content and spraying ZN significantly improved the vitamin C content of the fruit.With the delay of harvesting,the selenium content,total sugar content and total acid content of the "Lingfeng" grape fruit decreased,while the grapes sprayed with ZN showed the total sugar content increased slightly and the total acid decreased greatly.[Conclusions]It is suggested that if you plan to harvest at the right time,you can use "Jufu Selenium" as the exogenous fertilizer for selenium-enriched grapes;and if you want to postpone harvesting,you can use "Zhongnong No.6" as the selenium fertilizer.

Evaluation of Third-Order Method for the Tests of Variance Component in Linear Mixed Models

Mixed models provide a wide range of applications including hierarchical modeling and longitudinal studies. The tests of variance component in mixed models have long been a methodological challenge because of its boundary conditions. It is well documented in literature that the traditional first-order methods: likelihood ratio statistic, Wald statistic and score statistic, provide an excessively conservative approximation to the null distribution. However, the magnitude of the conservativeness has not been thoroughly explored. In this paper, we propose a likelihood-based third-order method to the mixed models for testing the null hypothesis of zero and non-zero variance component. The proposed method dramatically improved the accuracy of the tests. Extensive simulations were carried out to demonstrate the accuracy of the proposed method in comparison with the standard first-order methods. The results show the conservativeness of the first order methods and the accuracy of the proposed method in approximating the p-values and confidence intervals even when the sample size is small.

Mn-based MXene with high lithium-ion storage capacity

3d-transition metal(Fe,Co,Ni,and Mn)-based MXene materials have been predicted to demonstrate exceptional electrochemical performance because of their good electrical conductivity and the presence of metallic atoms with multiple charge states.However,until now,there have been no reports on MXenes based on Fe,Co,Ni,and Mn,due to the lack of 3d-metal-layered precursors.Herein,we successfully synthesized the first 3d-transition metal-based MXenes,Mn_(2)CT_(x) by exfoliating a layered precursor derived from the anti-perovskite bulk Mn3GaC.The as-prepared Mn_(2)CT_(x) MXene nanosheets were employed as anode materials in lithium-ion batteries,which exhibited stable storage capacity of 764.7 mAh·g^(-1) at 0.5 C,placing its storage capacities at an upper-middle level compared with other reported MXene materials as well as other Mn-based anode materials.Overall,this study opens a new avenue for MXene research by synthesizing 3d-transition metal-based MXenes for electrochemical applications.

Novel potential XOD inhibitory peptides derived from Trachinotus ovatus:Isolation,identification and structure-function analysis

This study aimed to isolate and identify the novel potential Xanthine oxidase(XOD)inhibitory peptides derived from Trachinotus ovatus hydrolysate(TOH)(hydrolysis by neutral protease),and investigate their structure-function relationship.Initially,TOH was separated to four fractions(F1–F4)by gel filtration chromatography and F4 was chosen with higher XOD inhibitory rate(85.16%±0.566,25 mg/mL)and lower molecular weight(95.73%,<1000 Da).F4 was further characterized by reversed-phase high performance liquid chromatography(RP-HPLC)coupled with Nano-HPLC-MS/MS and four peptides(FPAW,LLPW,WLLP and FHLP)were identified with IC50 value of 3.81±0.18 mM,4.17±0.12 mM,43.06±0.73 mM,and over 50.00 mM respectively.It can be concluded that Trp-containing peptides especially located in C-terminal could inhibit XOD effectively.Moreover,the XOD-inhibiting actions of these peptides involvedπ-πstacking(Phe914 and Phe1009 in XOD),hydrogen bonding via molecular docking.Lineweaver-Burk equation showed the inhibition type of FPAW was a mixed inhibition.Circular dichroism(CD)spectra indicated FPAW could combine and change the secondary structure of XOD.Therefore,two peptides of FPAW and LLPW might have potential to be used to alleviate hyperuricemia in the future.

Group-specific functional patterns of mitochondrion-related organelles shed light on their multiple transitions from mitochondria in ciliated protists

Adaptations of ciliates to hypoxic environments have arisen independently several times.Studies on mitochondrion-related organelle(MRO)metabolisms from distinct anaerobic ciliate groups provide evidence for understanding the transitions from mitochondria to MROs within eukaryotes.To deepen our knowledge about the evolutionary patterns of ciliate anaerobiosis,mass-culture and single-cell transcriptomes of two anaerobic species,Metopus laminarius(class Armophorea)and Plagiopyla cf.narasimhamurtii(class Plagiopylea),were sequenced and their MRO metabolic maps were compared.In addition,we carried out comparisons using publicly available predicted MRO proteomes from other ciliate classes(i.e.,Armophorea,Litostomatea,Muranotrichea,Oligohymenophorea,Parablepharismea and Plagiopylea).We found that single-cell transcriptomes were similarly comparable to their mass-culture counterparts in predicting MRO metabolic pathways of ciliates.The patterns of the components of the MRO metabolic pathways might be divergent among anaerobic ciliates,even among closely related species.Notably,our findings indicate the existence of group-specific functional relics of electron transport chains(ETCs).Detailed group-specific ETC functional patterns are as follows:full oxidative phosphorylation in Oligohymenophorea and Muranotrichea;only electron-transfer machinery in Armophorea;either of these functional types in Parablepharismea;and ETC functional absence in Litostomatea and Plagiopylea.These findings suggest that adaptation of ciliates to anaerobic conditions is group-specific and has occurred multiple times.Our results also show the potential and the limitations of detecting ciliate MRO proteins using single-cell transcriptomes and improve the understanding of the multiple transitions from mitochondria to MROs within ciliates.

Reliable and broad-range layer identification of Au-assisted exfoliated large area MoS_(2)and WS_(2)using reflection spectroscopic fingerprints

The emerging Au-assisted exfoliation technique enables the production of a wealth of large-area and high-quality ultrathin two dimensional(2D)crystals.Fast,damage-free,and reliable determination of the layer number of such 2D films can greatly promote layer-dependent physical studies and device applications.Here,an optical method has been developed for simple,high throughput,and accurate determination of the layer number for Au-assisted exfoliated MoS_(2)and WS_(2)films in a broad thickness range.The method is based on quantitative analysis of layer-dependent white light reflection spectra(WLRS),revealing that the intensity of exciton-induced reflection peaks can be used as a clear indicator for identifying the layer number.The simple yet robust method will facilitate fundamental studies on layer-dependent optical,electrical,and thermal properties and device applications of 2D materials.The technique can also be readily combined with photoluminescence(PL)and Raman spectroscopies to study other layer-dependent physical properties of 2D materials.