Ion thruster plumes from a multi-thruster array of different working configurations are simulated by a hybrid fluid-particle software. The particle in cell method is employed to model the transports of ions. The direc...Ion thruster plumes from a multi-thruster array of different working configurations are simulated by a hybrid fluid-particle software. The particle in cell method is employed to model the transports of ions. The direct simulation Monte Carlo method is used to model momentum and charge exchange （CEX） collisions. The software is based on unstructured grids which make it easy to handle with complex geometry. The results of chamber simulation are compared with experimental data in ion current density and number density, which show good agreements. The maximum difference of current density along the thruster centerline is less than 9.30%. The interaction effects of plumes when multiple thrusters are operating in vacuum are predicted. Distributions of single charged xenon ions are significantly different in the near-field plume flow, however, merge into one in the far downstream region. Moreover, the interaction effect on the spatial distribution of CEX xenon ions is displayed as well.展开更多
SUMMARY The p value has been widely used as a way to summarise the significance in data analysis. However, misuse and misinterpretation of the p value is common in practice. Our result shows that if the model specific...SUMMARY The p value has been widely used as a way to summarise the significance in data analysis. However, misuse and misinterpretation of the p value is common in practice. Our result shows that if the model specification is wrong, the distribution of the p value may be inappropriate, which makes the decision based on the p value invalid.展开更多
Diagnostic tests are usually based on some quantitative biomarkers.Two key parameters used to characterise the quality of a test are test sensitivity and specificity.Predictive values of the disease status based on te...Diagnostic tests are usually based on some quantitative biomarkers.Two key parameters used to characterise the quality of a test are test sensitivity and specificity.Predictive values of the disease status based on test results are also of interest in medical research and public health management.In this paper,we study the relations among sensitivity,specificity and predictive values of the test.The core concept is risk function,which is assumed to be an increasing function of the biomarker.Our results show that test sensitivity and specificity change in opposite directions.The positive predictive value and the sensitivity also change in opposite directions.Likewise,the negative predictive value and the specificity change in opposite directions.展开更多
Machine learning(ML)techniques have been widely used to address mental health questions.We discuss two main aspects of ML in psychiatry in this paper,that is,supervised learning and unsupervised learning.Examples are ...Machine learning(ML)techniques have been widely used to address mental health questions.We discuss two main aspects of ML in psychiatry in this paper,that is,supervised learning and unsupervised learning.Examples are used to illustrate how ML has been implemented in recent mental health research.展开更多
Objective Genotype has been related to specific phenotype of hypertrophic cardiomyopathy (HCM) patients, but its relationship with histopathological alterations remains uncertain. The purpose of the study is to explor...Objective Genotype has been related to specific phenotype of hypertrophic cardiomyopathy (HCM) patients, but its relationship with histopathological alterations remains uncertain. The purpose of the study is to explore the relationship between the genotype and histopathological alterations under different genetic Backgrounds.展开更多
Sample size justification is a very crucial part in the design of clinical trials. In this paper, the authors derive a new formula to calculate the sample size for a binary outcome given one of the three popular indic...Sample size justification is a very crucial part in the design of clinical trials. In this paper, the authors derive a new formula to calculate the sample size for a binary outcome given one of the three popular indices of risk difference.The sample size based on the absolute difference is the fundamental one, which can be easily used to derive sample size given the risk ratio or OR.展开更多
Suppose we have a sample of subjects in two treatment groups.To study the difference of the treatment effects,we can analyse the data using all subjects(overall analysis).We may also divide the subjects into several s...Suppose we have a sample of subjects in two treatment groups.To study the difference of the treatment effects,we can analyse the data using all subjects(overall analysis).We may also divide the subjects into several subgroups based on some covariates of interest(eg,gender),and study the treatment effects within each subgroup.The results of these two analyses may be different or even in opposite directions.In this paper,we give a general sufficient condition of consistency between the overall and subgroup analyses.展开更多
Mental health questions can be tackled through machine learning(ML)techniques.Apart from the two ML methods we introduced in our previous paper,we discuss two more advanced ML approaches in this paper:support vector m...Mental health questions can be tackled through machine learning(ML)techniques.Apart from the two ML methods we introduced in our previous paper,we discuss two more advanced ML approaches in this paper:support vector machines and artificial neural networks.To illustrate how these ML methods have been employed in mental health,recent research applications in psychiatry were reported.展开更多
Within the family of zero-inflated Poisson distributions, the data has Poisson distribution if any only if the mean equals the variance. In this paper we compare two closely related test statistics constructed based o...Within the family of zero-inflated Poisson distributions, the data has Poisson distribution if any only if the mean equals the variance. In this paper we compare two closely related test statistics constructed based on this idea. Our results show that although these two tests are asymptotically equivalent under the null hypothesis and are equally efficient, one test is always more efficient than the other one for small and medium sample sizes.展开更多
In this paper we study the relations of four possible generalized inverses of a general distribution functions and their right-continuity properties. We correct a right-continuity result of the generalized inverse use...In this paper we study the relations of four possible generalized inverses of a general distribution functions and their right-continuity properties. We correct a right-continuity result of the generalized inverse used in statistical literature. We also prove the validity of a new generalized inverse which is always right-continuous.展开更多
Tannins are kinds of polyphenols found in plants,which can be divided into hydrolyzed tannins and condensed tannins according to the structure.They are extracted using solid/liquid,supercritical,pressurized water,and ...Tannins are kinds of polyphenols found in plants,which can be divided into hydrolyzed tannins and condensed tannins according to the structure.They are extracted using solid/liquid,supercritical,pressurized water,and microwave-assisted extraction approaches.Because of the excellent antioxidant and antibacterial properties,tannins are widely used in medicine and food process.Considering the above advantages,the present review focused on various techniques to extract tannins and their application in the medical,food and chemical industries.展开更多
Amyotrophic lateral sclerosis(ALS)is a progressive neurodegenerative disease affecting both upper and lower motor neurons(MNs)with large unmet medical needs.Multiple pathological mechanisms are considered to contribut...Amyotrophic lateral sclerosis(ALS)is a progressive neurodegenerative disease affecting both upper and lower motor neurons(MNs)with large unmet medical needs.Multiple pathological mechanisms are considered to contribute to the progression of ALS,including neuronal oxidative stress and mitochondrial dysfunction.Honokiol(HNK)has been reported to exert therapeutic effects in several neurologic disease models including ischemia stroke,Alzheimer’s disease and Parkinson’s disease.Here we found that honokiol also exhibited protective effects in ALS disease models both in vitro and in vivo.Honokiol improved the viability of NSC-34 motor neuron-like cells that expressed the mutant G93A SOD1 proteins(SOD1-G93A cells for short).Mechanistical studies revealed that honokiol alleviated cellular oxidative stress by enhancing glutathione(GSH)synthesis and activating the nuclear factor erythroid 2-related factor 2(NRF2)-antioxidant response element(ARE)pathway.Also,honokiol improved both mitochondrial function and morphology via fine-tuning mitochondrial dynamics in SOD1-G93A cells.Importantly,honokiol extended the lifespan of the SOD1-G93A transgenic mice and improved the motor function.The improvement of antioxidant capacity and mitochondrial function was further confirmed in the spinal cord and gastrocnemius muscle in mice.Overall,honokiol showed promising preclinical potential as a multiple target drug for ALS treatment.展开更多
基金supported in part by the Novel Bio-statistical and Epidemiologic Methodology grants from the University of Rochester Medical Center Clinical and Translational Science Institute Pilot Awards Program
文摘Ion thruster plumes from a multi-thruster array of different working configurations are simulated by a hybrid fluid-particle software. The particle in cell method is employed to model the transports of ions. The direct simulation Monte Carlo method is used to model momentum and charge exchange （CEX） collisions. The software is based on unstructured grids which make it easy to handle with complex geometry. The results of chamber simulation are compared with experimental data in ion current density and number density, which show good agreements. The maximum difference of current density along the thruster centerline is less than 9.30%. The interaction effects of plumes when multiple thrusters are operating in vacuum are predicted. Distributions of single charged xenon ions are significantly different in the near-field plume flow, however, merge into one in the far downstream region. Moreover, the interaction effect on the spatial distribution of CEX xenon ions is displayed as well.
基金supported by a pilot grant(PI:Feng) from the Clinical and Translational Sciences Institute at the University of Rochester Medical Center(UR-CTSI GR500208)
文摘SUMMARY The p value has been widely used as a way to summarise the significance in data analysis. However, misuse and misinterpretation of the p value is common in practice. Our result shows that if the model specification is wrong, the distribution of the p value may be inappropriate, which makes the decision based on the p value invalid.
文摘Diagnostic tests are usually based on some quantitative biomarkers.Two key parameters used to characterise the quality of a test are test sensitivity and specificity.Predictive values of the disease status based on test results are also of interest in medical research and public health management.In this paper,we study the relations among sensitivity,specificity and predictive values of the test.The core concept is risk function,which is assumed to be an increasing function of the biomarker.Our results show that test sensitivity and specificity change in opposite directions.The positive predictive value and the sensitivity also change in opposite directions.Likewise,the negative predictive value and the specificity change in opposite directions.
文摘Machine learning(ML)techniques have been widely used to address mental health questions.We discuss two main aspects of ML in psychiatry in this paper,that is,supervised learning and unsupervised learning.Examples are used to illustrate how ML has been implemented in recent mental health research.
文摘Objective Genotype has been related to specific phenotype of hypertrophic cardiomyopathy (HCM) patients, but its relationship with histopathological alterations remains uncertain. The purpose of the study is to explore the relationship between the genotype and histopathological alterations under different genetic Backgrounds.
文摘Sample size justification is a very crucial part in the design of clinical trials. In this paper, the authors derive a new formula to calculate the sample size for a binary outcome given one of the three popular indices of risk difference.The sample size based on the absolute difference is the fundamental one, which can be easily used to derive sample size given the risk ratio or OR.
文摘Suppose we have a sample of subjects in two treatment groups.To study the difference of the treatment effects,we can analyse the data using all subjects(overall analysis).We may also divide the subjects into several subgroups based on some covariates of interest(eg,gender),and study the treatment effects within each subgroup.The results of these two analyses may be different or even in opposite directions.In this paper,we give a general sufficient condition of consistency between the overall and subgroup analyses.
文摘Mental health questions can be tackled through machine learning(ML)techniques.Apart from the two ML methods we introduced in our previous paper,we discuss two more advanced ML approaches in this paper:support vector machines and artificial neural networks.To illustrate how these ML methods have been employed in mental health,recent research applications in psychiatry were reported.
文摘Within the family of zero-inflated Poisson distributions, the data has Poisson distribution if any only if the mean equals the variance. In this paper we compare two closely related test statistics constructed based on this idea. Our results show that although these two tests are asymptotically equivalent under the null hypothesis and are equally efficient, one test is always more efficient than the other one for small and medium sample sizes.
文摘In this paper we study the relations of four possible generalized inverses of a general distribution functions and their right-continuity properties. We correct a right-continuity result of the generalized inverse used in statistical literature. We also prove the validity of a new generalized inverse which is always right-continuous.
基金This work was supported by College Students Innovation and Entrepreneurship Training Program in 2020(No.202010163002)Department of Education of Liaoning Province(No.LJKZ0918)Department of Science and Technology of Liaoning(2021JH2/10300069).
文摘Tannins are kinds of polyphenols found in plants,which can be divided into hydrolyzed tannins and condensed tannins according to the structure.They are extracted using solid/liquid,supercritical,pressurized water,and microwave-assisted extraction approaches.Because of the excellent antioxidant and antibacterial properties,tannins are widely used in medicine and food process.Considering the above advantages,the present review focused on various techniques to extract tannins and their application in the medical,food and chemical industries.
基金supported by the grants from National Natural Science Foundation of China(Nos.82073835 and 81872855)National Key R&D Program of China(No.2019YFC1708901)+2 种基金CAMS Innovation Fund for Medical Sciences(No.2021-I2M-1028)Beijing Key Laboratory of New Drug Mechanisms and Pharmacological Evaluation Study(BZ0150,China)Disciplines construction project(201920200802,China)。
文摘Amyotrophic lateral sclerosis(ALS)is a progressive neurodegenerative disease affecting both upper and lower motor neurons(MNs)with large unmet medical needs.Multiple pathological mechanisms are considered to contribute to the progression of ALS,including neuronal oxidative stress and mitochondrial dysfunction.Honokiol(HNK)has been reported to exert therapeutic effects in several neurologic disease models including ischemia stroke,Alzheimer’s disease and Parkinson’s disease.Here we found that honokiol also exhibited protective effects in ALS disease models both in vitro and in vivo.Honokiol improved the viability of NSC-34 motor neuron-like cells that expressed the mutant G93A SOD1 proteins(SOD1-G93A cells for short).Mechanistical studies revealed that honokiol alleviated cellular oxidative stress by enhancing glutathione(GSH)synthesis and activating the nuclear factor erythroid 2-related factor 2(NRF2)-antioxidant response element(ARE)pathway.Also,honokiol improved both mitochondrial function and morphology via fine-tuning mitochondrial dynamics in SOD1-G93A cells.Importantly,honokiol extended the lifespan of the SOD1-G93A transgenic mice and improved the motor function.The improvement of antioxidant capacity and mitochondrial function was further confirmed in the spinal cord and gastrocnemius muscle in mice.Overall,honokiol showed promising preclinical potential as a multiple target drug for ALS treatment.
