Asymptotic Theory for Multiple-Sample Semiparametric Density Ratio Models and Its Application to Mortality Forecasting

A multiple-sample semiparametric density ratio model, which is equivalent to a generalized logistic regression model, can be constructed by multiplicative exponential distortions of a reference distribution. Distortion functions are assumed to be nonnegative and of a known finite-dimensional parametric form, and the reference distribution is left as nonparametric. The combined data from all the samples are used in the semiparametric large sample problem of estimating each distortion and the reference distribution. The large sample behavior for both the parameters and the unknown reference distribution are studied. The estimated reference cumulative distribution function is proved to converge weakly to a zero-mean Gaussian process, whose covariance structure provides confidence bands for the reference distribution function. A Kolmogorov-Smirnov type statistic for a goodness-of-fit test of the density ratio model is also studied. In the second part, an approach to modeling and forecasting age-specific mortality in the United States is provided. The approach is based on an extension of a class of semiparametric models to time series. The method combines information from several time series and estimates their predictive distributions conditional on past data. The conditional expectation, the most common predictor, is obtained as a by product from the first moment of the predictive distribution. The confidence band of the predictor is obtained by applying the asymptotic results of the semiparametric density ratio model. A comparison of short term prediction is made between the semiparametric method and the well known method of Lee and Carter \cite{LC(1992)}. Judging by the mean square error (MSE) of prediction for all ages, the semiparametric method reduces the overall MSE appreciably

Change Profiles and Functional Targets of MicroRNAs in Type 2 Diabetes Mellitus Patients with Obesity

Background MicroRNAs (miRNAs) exert an essential contribution to obesity and type 2 diabetes mellitus (T2DM). This study aimed to investigate the differences of miRNAs in the presence and absence of T2DM in patients with obesity, as well as before and after bariatric surgery in T2DM patients with obesity. Characterization of the common changes in both was further analyzed. Methods We enrolled 15 patients with obesity but without T2DM and 15 patients with both obesity and T2DM. Their preoperative clinical data and serum samples were collected, as well as 1 month after bariatric surgery. The serum samples were analyzed by miRNA sequencing, and the miRNAs profiles and target genes characteristics were compared. Results Patients with T2DM had 16 up-regulated and 32 down-regulated miRNAs compared to patients without T2DM. Improvement in metabolic metrics after bariatric surgery of T2DM patients with obesity was correlated with changes in miRNAs, as evidenced by the upregulation of 20 miRNAs and the downregulation of 30 miRNAs. Analysis of the two miRNAs profiles identified seven intersecting miRNAs that showed opposite changes. The target genes of these seven miRNAs were substantially enriched in terms or pathways associated with T2DM. Conclusion We determined the expression profiles of miRNAs in the obese population, with and without diabetes, before and after bariatric surgery. The miRNAs that intersected in the two comparisons were discovered. Both the miRNAs discovered and their target genes were closely associated with T2DM, demonstrating that they might be potential targets for the regulation of T2DM

Possible Luttinger liquid behavior of edge transport in monolayer transition metal dichalcogenide crystals.

In atomically-thin two-dimensional (2D) semiconductors, the nonuniformity in current flow due to its edge states may alter and even dictate the charge transport properties of the entire device. However, the influence of the edge states on electrical transport in 2D materials has not been sufficiently explored to date. Here, we systematically quantify the edge state contribution to electrical transport in monolayer MoS2/WSe2 field-effect transistors, revealing that the charge transport at low temperature is dominated by the edge conduction with the nonlinear behavior. The metallic edge states are revealed by scanning probe microscopy, scanning Kelvin probe force microscopy and first-principle calculations. Further analyses demonstrate that the edge-state dominated nonlinear transport shows a universal power-law scaling relationship with both temperature and bias voltage, which can be well explained by the 1D Luttinger liquid theory. These findings demonstrate the Luttinger liquid behavior in 2D materials and offer important insights into designing 2D electronics

Ternary composite phase change materials (PCMs) towards low phase separation and supercooling: eutectic behaviors and application

Salt hydrates have been used as phase change materials (PCMs) for various types of Thermal Energy Storage (TES) especially for cold storage. In this project, a novel composite phase change material (PCM) consisted of mixed solution of inorganic salt and organic salt was developed and characterized. Firstly, the PCM solutions containing sodium formate, potassium chloride and water with various weight percentage were evaluated to understand their solidification temperature, melting temperature, the supercooling degree and the latent heat. Then a PCM with mass fractions at weight percentages of 22%/12%/66% with better performance was selected for further study to restrain the supercooling. Different gelling agents and nucleate agents were employed in this PCM. The results show that the addition of 0.6 wt% xanthan gum can effectively prevent the phase separation and leakage, while 0.6 wt% of nano-TiO2 is the best nucleating agent since the supercooling can be reduced to 2.6 °C, which is 67.9% lower than that of the original PCM without any nucleating agent. Finally, the novel PCM was tested for frozen food storage application, in which the food temperature could be maintained below -18 °C for over 10 hours in the insulated box. This indicated the suitability of developed PCM for frozen food storage and transportation

Development and Application Effect of Knowledge-to-action Framework-based Health Management in Adolescents with Depressive Disorder in Remote Counties

BackgroundThe prevalence of depressive disorder in adolescents is increasing. Adolescents with depressive disorder in remote counties and their families have a low awareness of the disease, and often are difficult to complete the whole treatment.ObjectiveTo explore the application effect of knowledge-to-action (KTA) framework-based health management in adolescents with depressive disorder in remote counties.MethodsNinety-four adolescents with depressive disorder coming from remote countries were recruited from the Second Affiliated Hospital of Nanchang University from June to December 2020. They were randomly divided into a routine group (receiving a 12-week routine health management) and a KTA group (receiving a 12-week KTA framework-based health management) . At the time of enrollment and 12 weeks after intervention, the status of non-suicidal self-injury was assessed by the Adolescent Non-suicidal Self-injury Assessment Questionnaire (ANSAQ) , mobile phone use was evaluated by the Self-rating Questionnaire for Adolescent Problematic Mobile Phone Use (SQAPMPU) , the anxiety was evaluated with the score of the Screen for Child Anxiety Related Emotional Disorders (SCARED) , and the depression was assessed by the Depression Self-Rating Scale for Childhood (DSRS) .ResultsTwo groups had no significant differences in mean total scores of ANSAQ, SQAPMPU, SCARED, and DSRS before receiving intervention (P>0.05) .Two groups had no significant differences in each dimension score of SQAPMPU before receiving intervention (P>0.05) .After the 12-week intervention, the mean total scores of ANSAQ, SQAPMPU, SCARED, and DSRS decreased significantly in both groups (P<0.05) , and they were lowered more significantly in the KTA group (P<0.05) , the each dimension score of SQAPMPU decreased significantly in both groups (P<0.05) , and they were lowered more significantly in the KTA group (P<0.05) .ConclusionKTA framework-based health management could effectively reduce the incidence of non-suicidal self-injury and the problematic use rate of mobile phones, relieve the anxiety and depression in adolescents with depressive disorder in remote counties, indicating that this type of health management may have good applicability as an outpatient management in this group

A novel authigenic magnetite source for sedimentary magnetization

We report a novel authigenic nanoscale magnetite source in marine methane seep sediments. The magnetite occurs in large concentrations in multiple horizons in a 230 m sediment core with gas hydrate-bearing intervals. In contrast to typical biogenic magnetite produced by magnetotactic bacteria and dissimilatory iron-reducing bacteria, most particles have sizes of 200-800 nm and many are aligned in distinctive structures that resemble microbial precipitates. The magnetite is interpreted to be a byproduct of microbial iron reduction within methanic sediments with rapidly changing redox conditions. Iron sulfides that accumulated at a shallow sulfate-methane transition zone were oxidized after methane seepage intensity decreased. The alteration process produced secondary iron (oxyhydr)oxides that then became a reactive iron source for magnetite authigenesis when methane seepage increased again. This interpretation is consistent with C depletion in coexisting carbonate nodules. The authigenic magnetite will record younger paleomagnetic signals than surrounding sediments, which is important for pa-leomagnetic interpretations in seep systems. The microbial and possibly abiotic processes that caused these magnetic minerals to form at moderate burial depths remain to be determined.This research was funded by the National Key Research and Development Program of China (grant 2018YFC0310004 and 2018YFA0702605), the National Natural Science Foundation of China (grants 41806049, 41876038, and 91128101), the Guangdong Special Fund for Economic Development (Marine Economy, grant GDME-2018D001), the China Geological Survey Project for South China Sea Gas Hydrate Resource Exploration (grant DD20160211

Evaluation of the efficacy and safety of intravenous remdesivir in adult patients with severe COVID-19: study protocol for a phase 3 randomized, double-blind, placebo-controlled, multicentre trial.

BACKGROUND: Coronavirus disease 2019 (COVID-19), caused by a novel corinavirus (later named SARS-CoV-2 virus), was fistly reported in Wuhan, Hubei Province, China towards the end of 2019. Large-scale spread within China and internationally led the World Health Organization to declare a Public Health Emergency of International Concern on 30th January 2020. The clinical manifestations of COVID-19 virus infection include asymptomatic infection, mild upper respiratory symptoms, severe viral pneumonia with respiratory failure, and even death. There are no antivirals of proven clinical efficacy in coronavirus infections. Remdesivir (GS-5734), a nucleoside analogue, has inhibitory effects on animal and human highly pathogenic coronaviruses, including MERS-CoV and SARS-CoV, in in vitro and in vivo experiments. It is also inhibitory against the COVID-19 virus in vitro. The aim of this study is to assess the efficacy and safety of remdesivir in adult patients with severe COVID-19. METHODS: The protocol is prepared in accordance with the SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) guidelines. This is a phase 3, randomized, double-blind, placebo-controlled, multicentre trial. Adults (≥ 18 years) with laboratory-confirmed COVID-19 virus infection, severe pneumonia signs or symptoms, and radiologically confirmed severe pneumonia are randomly assigned in a 2:1 ratio to intravenously administered remdesivir or placebo for 10 days. The primary endpoint is time to clinical improvement (censored at day 28), defined as the time (in days) from randomization of study treatment (remdesivir or placebo) until a decline of two categories on a six-category ordinal scale of clinical status (1 = discharged; 6 = death) or live discharge from hospital. One interim analysis for efficacy and futility will be conducted once half of the total number of events required has been observed. DISCUSSION: This is the first randomized, placebo-controlled trial in COVID-19. Enrolment began in sites in Wuhan, Hubei Province, China on 6th February 2020. TRIAL REGISTRATION: ClinicalTrials.gov: NCT04257656. Registered on 6 February 2020