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Thermoelectric transport enhancement of Te-rich bismuth antimony telluride(Bi_(0.5)Sb_(1.5)Te_(3+x))through controlled porosity

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Journal of Materiomics 2020年第3期6卷 532-544页

作者： Ian T.Witting Jann A.grovogui Vinayak P.Dravid g.Jeffrey Snyder Department of Materials Science and Engineering Northwestern University2220 Campus DriveCook Hall 2036EvanstonIL60208USA

Alloys of Bi_(2)Te_(3) and Sb_(2)Te_(3) are the best performing p-type thermoelectrics near room temperature and have been the subject of extensive engineering *** improvement is achieved by introducing defects that effectively scatter phonons and reduce thermal ***,outstanding results are often difficult to reproduce as the process variables involved are difficult to control or possibly ***,a reproducible and controllable method of fabricating porous Bi_(0.5)Sb_(1.5)Te_(3+x) is *** effective medium theory(EMT)predicts no benefit,improvements in the thermoelectric quality factor,B(which determines the maximum zT of a materials),were as high as 45% parallel to the pressing direction for a sample of roughly 20% *** study of microstructural evolution with increasing porosity is facilitated by a combination of Scanning/Transmission Electron Microscopy(S/TEM)and Electron Backscattered Diffraction(EBSD).This study reveals a statistically significant shift in the distribution of grain boundaries favoring lower energy twins,which coincides with an increase in the presence of stepped twin *** work demonstrates the potential benefits of careful grain boundary engineering and the need for further detailed studies of the dependence of thermal and electrical transport on grain boundary structure and orientation in these alloys.

关键词： Bismuth antimony telluride Thermoelectric Porosity Transport modeling Foaming

Vitamin D deficiency and hepatitis viruses-associated liver diseases:a literature review

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World Journal of gastroenterology 2018年第4期24卷 445-460页

作者： Nghiem Xuan Hoan Hoang Van Tong Le Huu Song Christian g Meyer Thirumalaisamy P Velavan Institute of Clinical Infectious Diseases 108 Military Central HospitalHanoi 10004Vietnam Molecular genetics of Infectious Diseases Institute of Tropical MedicineUniversity of TübingenTübingen 72074Germany Vietnamese-german Center of Medical Research(Vg-CARE) Hanoi 10004Vietnam Institute of Biomedicine and Pharmacy Vietnam Military Medical UniversityHanoi 10004Vietnam Medical Faculty Duy Tan UniversityDa NangVietnam

The secosteroid hormone vitamin D has, in addition to its effects in bone metabolism also functions in the modulation of immune responses against infectious agents and in inhibiting tumorigenesis. Thus, deficiency of vitamin D is associated with several malignancies, but also with a plethora of infectious diseases. Among other communicable diseases, vitamin D deficiency is involved in the pathogenesis of chronic liver diseases caused by hepatitis B and C viruses(HBV, HCV) and high prevalence of vitamin D deficiency with serum levels below 20 mg/mL in patients with HBV and HCV infection are found worldwide. Several studies have assessed the effects of vitamin D supplementation on the sustained virological response(SVR) to interferon(IFN) plus ribavirin(RBV) therapy in HBV and HCV infection. In these studies, inconsistent results were reported. This review addresses general aspects of vitamin D deficiency and, in particular, the significance of vitamin D hypovitaminosis in the outcome of HBVand HCV-related chronic liver diseases. Furthermore,current literature was reviewed in order to understand the effects of vitamin D supplementation in combination with IFN-based therapy on the virological response in HBV and HCV infected patients.

关键词： Vitamin D vitamin D deficiency chronic liver disease hepatitis B virus infection hepatitis C virus infection liver cirrhosis hepatocellular carcinoma sustained virological response vitamin D supplementation

Antioxidants: Friend or foe?

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Asian Pacific Journal of Tropical Medicine 2017年第12期10卷 1111-1116页

作者： R.Sarangarajan S.Meera R.Rukkumani P.Sankar g.Anuradha Department of Oral Pathology Madha Dental CollegeKundrathurChennaiIndia Private Dental Practitioner Sree Sai Dental CareChennaiIndia Department of Biochemistry and Molecular Biology School of Life SciencesPondicherry UniversityPuducherryIndia Private Dental Practitioner Sai Raghav Dental ClinicChennaiIndia

Reactive oxygen species are the intermediates that are formed during the normal metabolic process which are effectively neutralized by the antioxidant system of the *** imbalance in this neutralization process causes oxidative stress which has been implicated as one of the cause in diseases such as Alzheimer's disease, cardiovascular disorders, cancer etc. Research has enabled the use of antioxidants as therapeutic agents in the treatment of various diseases. Literature also puts forth the negative effects of using antioxidants in the treatment of diseases. This review is a compilation of both the beneficial and detrimental effects of use of antioxidants in the treatment of diseases such as cancer, cardiovascular diseases, diabetes and oral diseases.

关键词： Antioxidants Oxidative stress Reactive oxygen species Therapeutic agent

Conventional sintered Cu_(2-x)Se thermoelectric material

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Journal of Materiomics 2019年第4期5卷 626-633页

作者： Zhiming geng Dongliang Shi Lu Shi Ying Li g.Jeffrey Snyder Kwok-ho Lam Department of Electrical Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong Kong Department of Materials Science and Engineering Northwestern UniversityEvanstonUSA

As the featured material of the superionic thermoelectric(TE)material family,copper-chalcogenide Cu_(2-x)Se is attracting growing research interest for its excellent TE performance derived from the satisfactory power factor and the ultra-low thermal conductivity induced by the superionic *** efforts have been made and proved to be effective to further enhance the TE performance for Cu_(2-x)***,this material is still far from the application stage,which is mainly due to concerns regarding control of the properties and the costly complex fabrication *** we report a scalable pathway to achieve high-performance and tunable Cu_(2-x)Se,utilizing conventional sintering technology and copper(Cu)-vacancy engineering with an effective mass *** figure of merit zT is a competitive value of 1.0 at 800 K for the optimized binary Cu_(2-x)Se,based on the precise modeling prediction and Cu-vacancy *** changes in TE properties of Cu_(2-x)Se under heating-cooling cycle tests are also *** work offers the referable method along with the decent parent material for further enhancement of TE performance,paving a possible route for the application and industrialization of Cu_(2-x)Se TE materials.

关键词： Thermoelectric Copper selenide Copper-vacancy engineering Effective mass model

Spectral feature characterization and nitrogen content prediction in soils with different particle sizes and moisture contents

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International Journal of Agricultural and Biological Engineering 2008年第1期1卷 43-50页

作者： He Yong Shao Yongni Annia garcía Pereira Antihus Alexander Hernández gómez Cen Haiyan College of Biosystems Engineering and Food Science Zhejiang University268 Kaixuan RoadHangzhou 310029China

The objective of this research is to analyze the influences of light source incidence angle,fiber height,moisture content,and particle size on loamy mixed soil ***(N)content calibration and cross-validation models at different moisture contents and particle sizes were obtained using partial least squares(PLS)*** data were collected using a *** height of 100 mm and light source angle at 45°were chosen to obtain the sharpest spectra without apparent scattering *** results show that moisture content and particle size strongly influenced the absorbance of the spectra,and a better N prediction model was obtained when the particle sizes were in the ranges of 0.5-1.0,1.0-2.0 and 2.0-5.0 mm,with the correlation coefficients(r)of 0.819,0.815 and 0.818,and standard errors of prediction(SEP)of 2.29,2.41 and 2.42 mg/kg,*** N prediction model was obtained when the soil was kept in its natural moisture content with r of 0.575 and SEP of 3.275 mg/kg,compared to the performance of dried soil samples with r of 0.815 and SEP of 2.425 mg/kg.

关键词： spectral feature prediction model soil moisture nitrogen content near infrared reflectance spectroscopy partial least squares

A mathematical model of cholera in a periodic environment with control actions

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International Journal of Biomathematics 2020年第4期13卷 109-140页

作者： g.Kolaye I.Damakoat S.Bowong R.Houe D.Bekolle Saint Jerome Polytechnic Saint Jerome Catholic University Institute of Douala P.O.Box 5949 Douala Cameroon Department of Mathematics and Computer Science Faculty of Science University of Ngaoundere P.O.Box 454 NgaoundereCameroon Laboratory of Mathematics Department of Mathematics and Computer Science Faculty of Science University of Douala P.O.Box 24157 DoualaCameroon UMI 209 IRD/UPMC UMMISCO Bondy-France and Project gRIMCAPE LIRIMA University of Yaounde ICameroon University of Toulouse INPTLGP-ENIT 47 Avenue d'AzereixBP 1629F-65016 Tarbes CedexFrance

In this paper,we studied the impact of sensitization and sanitation as possible control actions to curtail the spread of cholera epidemic within a human ***,we combined a model of Vibrio Cholerae with a gencric SIRS cholera *** control strategies in terms of the sensitization of population and sanitation are integrated through the impulsive differential *** we presented the theoretical analysis of the *** precisely,we computed the disease free *** derive the basic reproduction number R0 which determines the extinction and the persistence of the *** show that the trivial disease-free equilibrium is globally asymptotically stable whenever.R0≤1,while when R0>1,the trivial disease-free equilibrium is unstable and there exists a unique endemic equilibrium point which is globally asymptotically *** results are supported by numerical simulations,which further suggest that the control of cholera should consider both sensitization and san itation,with a strong focus on the latter.

关键词： Sensitization sanitation Vibrio Cholerae\cholera and control

A UNIFORMLY CONVERgENT FINITE DIFFERENCE METHOD FOR A SINgULARLY PERTURBED INITIAL VALUE PROBLEM

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Applied Mathematics and Mechanics(English Edition) 1999年第4期20卷 40-48页

作者： g. M. Amiraliyev, Hakk Duru Department of Mathematics, Y Y University, 65080 VAN, TURKEY Department of Mathematics Y Y University Van Turkey

Initial value problem for linear second order ordinary differential equation with small parameter by the first and second derivatives is considered. An exponentially fitted difference scheme with constant fitting factors is developed in a uniform mesh, which gives first_order uniform convergence in the sense of discrete maximum norm. Numerical results are also presented.

关键词： singular perturbation difference scheme uniform convergence initial value condition linear ordinary differential equation

Could the burden of pancreatic cancer originate in childhood?

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World Journal of gastroenterology 2021年第32期27卷 5322-5340页

作者： Smaranda Diaconescu georgiana Emmanuela gîlcă-Blanariu Silvia Poamaneagra Otilia Marginean gabriela Paduraru gabriela Stefanescu Department of Pediatrics “Grigore T.Popa”University of Medicine and PharmacyIasi 700115Romania Department of Pediatric gastroenterology St Mary Emergency Children's HospitalIasi 700309Romania Department of gastroenterology and Hepatology "Grigore T.Popa"University of Medicine and PharmacyIasi 700115Romania Department of gastroenterology and Hepatology “St.Spiridon”Emergency HospitalIasi 700111Romania Doctoral School George Emil Palade University of MedicinePharmacyScience and TechnologyTargu Mures 540142Romania Department of Pediatrics Research Center of Disturbance of Growth and Development on Children-BeliveUniversity of Medicine and Pharmacy“Victor Babes”TimisoaraTimisoara 300041Romania First Clinic of Pediatrics "Louis Turcanu"Emergency Childen's HospitalTimisoara 300011Romania

The presence of pancreatic cancer during childhood is extremely rare,and physicians may be tempted to overlook this diagnosis based on age ***,there are primary malignant pancreatic tumors encountered in pediatric patients,such as pancreatoblastoma,and tumors considered benign in general but may present a malignant potential,such as the solid pseudo-papillary tumor,insulinoma,gastrinoma,and vasoactive intestinal peptide secreting *** early diagnosis and management are of paramount importance since the survival rates tend to differ for various types of these *** pediatric cancers may present pancreatic metastases,such as renal cell carcinoma,which may evolve with pancreatic metastatic disease even after two or more *** childhood diseases may create a predisposition for the development of pancreatic cancer during adulthood;hence,there is a need for extensive screening strategies and complex programs to facilitate the transition from pediatric to adult ***,genetic studies highlight the fact the specific gene mutations and family aggregations may be correlated with a special predisposition towards pancreatic *** review aims to report the main pancreatic cancers diagnosed during childhood,the most important childhood diseases predisposing to the development of pancreatic malignancies,and the gene mutations associates with pancreatic malignant tumors.

关键词： Pancreatic cancer Pancreatic metastasis Childhood Adult Screening Transition

Molecular dynamics of amorphous pharmaceutical fenofibrate studied by broadband dielectric spectroscopy

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Journal of Pharmaceutical Analysis 2016年第3期6卷 165-170页

作者： U. Sailaja M. Shahin Thayyil N.S. Krishna Kumar g. govindaraj Department of Physics M.E.S Keveeyam College. Valanchery 676552 Malappuram Kerala India Department of Physics University of Calicut 673635 Kerala. India Department of Physics School of Physical Chemical and Applied Sciences Pondicherry University Puducherry 605014 India

Fenofibrate is mainly used to reduce cholesterol level in patients at risk of cardiovascular disease. Thermal transition study with the help of differential scanning calorimetry （DSC） shows that the aforesaid active pharmaceutical ingredient （API） is a good glass former. Based on our DSC study, the molecular dynamics of this API has been carried out by broadband dielectric spectroscopy （BDS） covering wide temperature and frequency ranges. Dielectric measurements of amorphous fenofibrate were per- formed after its vitrification by fast cooling from a few degrees above the melting point （Tm=354.11 K） to deep glassy state. The sample does not show any crystallization tendency during cooling and reaches the glassy state. The temperature dependence of the structural relaxation has been fitted by single Vogel- Fulcher-Tamman （VFT） equation. From VFT fit, glass transition temperature （Tg） was estimated as 250.56 K and fragility （m） was determined as 94.02. This drug is classified as a fragile glass former. Deviations of experimental data from Kohlrausch-Williams-Watts （KWW） fits on high-frequency flank of α-peak indicate the presence of an excess wing in fenofibrate. Based on Ngai＇s coupling model, we identified the excess wing as true Johari-goldstein （Jg） process. Below the glass transition temperature one can clearly see a secondary relaxation （γ） with an activation energy of 32.67 kJ/mol.

关键词： Amorphous fenofibrate Bioavailability Broadband dielectric spectroscopy glass transition Molecular dynamics