119 research outputs found
MAJOR DEPRESSION AND INSULIN RESISTANCE AMONG NONDIABETIC U.S. ADULTS AGED 20-39 YEARS: THE ROLES OF GENDER AND RACE/ETHNICITY
The relationship between depression and insulin resistance has been evaluated in previous studies but with conflicting results. No study was found that investigates the role of race/ethnicity in the relationship between depression and insulin resistance. The purpose of this study was to: 1) determine the prevalence of major depression and insulin resistance among nondiabetic young adults aged 20-39 years in the United States, 2) examine the relationship between major depression and insulin resistance among nondiabetic young adults aged 20-39 years in the United States, and 3) determine whether this relationship varies by gender, race/ethnicity, or measure of depression. Analyses of cross-sectional data from the National Health and Nutrition Examination Survey (NHANES) 1999-2008 were performed. The study sample consisted of 1,054 (46.5%) men and 1,211 (53.5%) women who were nondiabetic and aged 20-39 years (N = 2,265). Major depression was measured by the Composite International Diagnostic Interview in NHANES 1999-2004 and by the Patient Health Questionnaire-9 in NHANES 2005-2008. Insulin resistance was measured by the homeostasis model assessment for insulin resistance. The prevalence of major depression and insulin resistance among nondiabetic U.S. adults aged 20-39 years in the study was 3.7% (n = 84; weighted % = 3.8) and 25.7% (n = 582; weighted % = 22.7) respectively. No significant association was found between major depression and insulin resistance in bivariate logistic regression analysis. However, a significant interaction effect between gender and major depression was observed. For men, major depression was negatively associated with insulin resistance after adjusting for age, race/ethnicity, systolic blood pressure, triglyceride level, high-sensitivity C-reactive protein, obesity, leisure time physical activity, smoking, and alcohol consumption. In contrast, no significant association between major depression and insulin resistance among women was found. There was no significant interaction between race/ethnicity and major depression. No significant variations in the relationship between major depression and insulin resistance by measure of depression were revealed. Study findings provide support for a significant positive relationship between insulin resistance and 1) systolic blood pressure, 2) triglyceride level, 3) and obesity as measured by body mass index or waist circumference among nondiabetic young adults aged 20-39 years
The feasibility of Sn, In, or Al doped ZnSb thin film as candidates for phase change material
The potentials of Sn, In, or Al doped ZnSb thin film as candidates for phase change materials have been studied in this paper. It was found that the Zn-Sb bonds were broken by the addition of the dopants and homopolar Zn-Zn bonds and other heteropolar bonds, such as Sn-Sb, In-Sb, and Al-Sb, were subsequently formed. The existence of homopolar Sn-Sn and In-In bonds in
Znā
āSbāāSnāā and ZnāāSbāāInāā films, but no any Al-Al bonds in Znāā
SbāāAlāā
film, was confirmed. All these three amorphous films crystallize with the appearance of crystalline rhombohedral Sb phase, and Znāā
Sbāā
Alāā
film even exhibits a second crystallization process where the crystalline AlSb phase is separated out. The Znāā
SbāāAlāā
film exhibits a reversible phase change behavior with a larger Ea ( 4.7 eV), higher Tc (~ 245į“¼ C), better 10-yr data retention (~ 182į“¼ C), less incubation time (20 ns at 70 mW), and faster complete crystallization speed (45 ns at 70 mW). Moreover,
Znāā
SbāāAlāā
film shows the smaller root-mean-square (1.654 nm) and less change of the thickness between amorphous and crystalline state (7.5%), which are in favor of improving the reliability of phase change memory.This work was financially supported by the Natural
Science Foundation of China (Grant Nos. 61306147,
61377061), the Public Project of Zhejiang Province (Grant
No.2014C31146), the Young Leaders of academic climbing
project of the Education Department of Zhejiang Province
(pd2013092), the Natural Science Foundation of Zhejiang
Province (Grant No. LQ15F040002), the Scientific Research
Foundation of Graduate School of Ningbo University, and sponsored by K. C. Wong Magna Fund in Ningbo
University
Phase change behaviors of Zn-doped Ge2Sb2Te5 films
This work was financially supported by the Program for
New Century Excellent Talents in University (Grant No.
NCET-10-0976), the International Science & Technology
Cooperation Program of China (Grant No. 2011DFA12040),
the National Program on Key Basic Research Project (973
Program) (Grant No. 2012CB722703), the Natural Science
Foundation of China (Grant Nos. 61008041 and 60978058),
the Natural Science Foundation of Zhejiang Province, China
(Grant No. Y1090996), the Natural Science Foundation of
Ningbo City, China (Grant No. 2011A610092), the Program
for Innovative Research Team of Ningbo city (Grant No.
2009B21007), and sponsored by K. C. Wong Magna Fund in
Ningbo University
Enhanced thermal stability and electrical behavior of Zn-doped Sb2Te films for phase change memory application
Zn-doped SbāTe films are proposed to present the feasibility for phase-change memory application. Zn atoms are found to significantly increase crystallization temperature of Zn x (SbāTe)1āx films and be almost linearly with the wide range of Zn-doping concentration from xā=ā0 to 29.67 at.%. Crystalline resistances are enhanced by Zn-doping, while keeping the large amorphous/crystalline resistance ratio almost constant at ā¼10āµ. Especially, the Zn 26.07 (SbāTe)73.93 and Zn 29.67 (SbāTe)70.33 films exhibit a larger resistance change, faster crystallization speed, and better thermal stability due to the formation of amorphous Zn-Sb and Zn-Te phases as well as uniform distribution of SbāTe crystalline grains
Improved phase-change characteristics of Zn-doped amorphous SbāTeā films for high-speed and low-power phase change memory
The superior performance of Zn-doped SbāTeā films might be favorable for the application in phase change memory. It was found that Zn dopants were able to suppress phase separation and form single stable Sb2Te crystal grain, diminish the grain size, and enhance the amorphous thermal stability of SbāTeā film. Especially, Zn 30.19(SbāTeā)69.81 film has higher crystallization temperature (ā¼258āĀ°C), larger crystallization activation energy (ā¼4.15āeV), better data retention (ā¼170.6āĀ°C for 10āyr), wider band gap (ā¼0.73āeV), and higher crystalline resistance. The minimum times for crystallization of Zn 30.19(SbāTeā)69.81 were revealed to be as short as ā¼10āns at a given proper laser power of 70āmW.This work was financially supported by the International
Science & Technology Cooperation Program of China
(Grant No. 2011DFA12040), the National Program on Key
Basic Research Project (973 Program) (Grant No.
2012CB722703), the Natural Science Foundation of China
(Grant Nos. 61008041 and 60978058), the CAS Special
Grant for Postgraduate Research, Innovation and Practice,
the Program for Innovative Research Team of Ningbo city
(Grant No. 2009B21007), and sponsored by K. C. Wong
Magna Fund in Ningbo University
Freely adjusted properties in GeāS based chalcogenide glasses with iodine incorporation
International audienceIn this study, we examined the function of halogen iodine acting as a glass network modifier in green chalcogenide glasses based on the GeāS system. We obtained a series of GeāSāI glasses and determined their glass-forming region. We then recorded the physical, thermal, and optical properties and studied the effect of halogen iodine on GeāSāI glasses. Results show that these glasses have relatively wide optical transmission window for infrared (IR) applications. The softening temperature of GeāSāI glasses varies from 210.54 Ā°C to 321.63 Ā°C, this temperature fits well with some kinds of high-temperature polymers, such as PES and PEI, the polymers serve as protective layers with high strength and flexibility, thus simplifying the fabrication processes of IR chalcogenide glass fiber. Finally, we performed a purification process to eliminate impurities and to improve optical spectr
Te-based chalcogenide films with high thermal stability for phase change memory
This study reports on the synthesis of tellurium-based chalcogenide films that have high thermal stability for phase change memory application. Several Te-based chalcogenide alloys of In-Bi-Te, Ag-Bi-Te, In-Sb-Te, Sn-Sb-Te, Zn-Ge-Te, and Ga-Ge-Te are reported. Their thermal, optical, and electrical properties are investigated. The results show that Bi-Te-based films have a higher crystallization temperature and greater activation energy compared with the other Sb-Te-based and Ge-Te-based films. Especially, Inā.āBiāā.āTeāā.āfilm exhibits high crystallization temperature (252āĀ°C) and great activation energy (5.16āeV), showing much improved amorphous thermal stability. A relatively wider optical band gap (0.674āeV) of thermal annealed Inā.āBiāā.āTeāā.āfilm is obtained. In addition, it also has a higher amorphous/crystalline resistance ratio of about 10āµ, implying that current consumption could be low in the phase-change memory operation.This work was financially supported by the Natural Science
Foundation of China (Grant Nos. 61008041, 61107047, and 60978058), the Natural Science Foundation of Zhejiang
Province, China (Grant No. Y1090996), the Natural Science
Foundation of Ningbo City, China (Grant No.
2011A610092), the Ningbo optoelectronic materials and
devices creative team (Grant No. 2009B21007), the Open
Research Fund of State Key Laboratory of Transient Optics
and Photonics, Chinese Academy of Sciences (Grant No.
SKLST201010), and sponsored by K. C. Wong Magna Fund
in Ningbo University
Novel GeāGaāTeāCsBr Glass System with Ultrahigh Resolvability of Halide
International audienceCO2 molecule, one of the main molecules to create new life, should be probed accurately to detect the existence of life in exoplanets. The primary signature of CO2 molecule is approximately 15 Ī¼m, and traditional S- and Se-based glass fibers are unsuitable. Thus, Te-based glass is the only ideal candidate glass for far-infrared detection. In this study, a new kind of Te-based chalcohalide glass system was discovered with relatively stable and large optical band gap. A traditional melt-quenching method was adopted to prepare a series of (Ge15Ga10Te75)100-x (CsBr)x chalcogenide glass samples. Experiment results indicate that the glass-forming ability and thermal properties of glass samples were improved when CsBr was added in the host of GeāGaāTe glass. GeāGaāTe glass could remarkably dissolve CsBr content as much as 85 at.%, which is the highest halide content in all reports for Te-based chalcohalide glasses. Moreover, ĪT values of these glass samples were all above 100 Ā°C. The glass sample (Ge15Ga10Te75)65 (CsBr)35 with ĪT of 119 Ā°C was the largest, which was 7 Ā°C larger than that of Ge15Ga10Te75 host glass. The infrared transmission spectra of these glasses show that the far-infrared cut-off wavelengths of (Ge15Ga10Te75)100-x (CsBr)x chalcogenide glasses were all beyond 25 Ī¼m. In conclusion, (Ge15Ga10Te75)100-x (CsBr)x chalcogenide glasses are potential materials for far-infrared optical applicatio
Novel NaI improved GeāGaāTe far-infrared chalcogenide glasses
International audienceIn this study, a novel Te-based glass system was investigated. Some properties of GeāGaāTeāNaI chalcogenide glasses such as physical, thermal and optical transmitting were discussed. XRD patterns show this glass system with best amorphous state can dissolve content of NaI as much as 35 at.%. The lowest cut-off wavelength of glass samples is 1645 nm which is the smallest wavelength among the reported Te-based glasses doping with halide. DSC curves indicate that all glass samples have good thermal stabilities (ĪT > 100 Ā°C) and the highest ĪT value corresponding to (Ge15Ga10Te75)85(NaI)15 glass is 120 Ā°C which is 8 Ā°C greater than that of GeāGaāTe host glass. The infrared spectra manifest GeāGaāTeāNaI chalcogenide glass system has a wide infrared transmission window between 1.6 Ī¼m and 20 Ī¼m. Consequently, GeāGaāTeāNaI glasses can be a candidate material for far infrared optic imaging and bio-sensing application
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