Binary Oxide p-n Heterojunction Piezoelectric Nanogenerators with an Electrochemically Deposited High p-Type Cu2O Layer.

PubMed

Baek, Seung Ki; Kwak, Sung Soo; Kim, Joo Sung; Kim, Sang Woo; Cho, Hyung Koun

2016-08-31

The high performance of ZnO-based piezoelectric nanogenerators (NGs) has been limited due to the potential screening from intrinsic electron carriers in ZnO. We have demonstrated a novel approach to greatly improve piezoelectric power generation by electrodepositing a high-quality p-type Cu2O layer between the piezoelectric semiconducting film and the metal electrode. The p-n heterojunction using only oxides suppresses the screening effect by forming an intrinsic depletion region, and thus sufficiently enhances the piezoelectric potential, compared to the pristine ZnO piezoelectric NG. Interestingly, a Sb-doped Cu2O layer has high mobility and low surface trap states. Thus, this doped layer is an attractive p-type material to significantly improve piezoelectric performance. Our results revealed that p-n junction NGs consisting of Au/ZnO/Cu2O/indium tin oxide with a Cu2O:Sb (cuprous oxide with a small amount of antimony) layer of sufficient thickness (3 μm) exhibit an extraordinarily high piezoelectric potential of 0.9 V and a maximum output current density of 3.1 μA/cm(2).

Management of lactating sows during heat stress: effects of water drip, snout coolers, floor type and a high energy-density diet.

PubMed

McGlone, J J; Stansbury, W F; Tribble, L F

1988-04-01

Two experiments using 120 sows were conducted to determine the effects during heat stress of two floor types, snout coolers or a water drip system, and a high energy-density diet. During both studies, air temperature was maintained at or above 29 degrees C. Floor types included partially slotted concrete and plastic-coated, expanded metal. In Exp. 1, in addition to floor-type treatments, snout coolers were on or off and the water drip was on for 3 min each 10 min or off. Snout coolers increased (P less than .05) sow feed intake and decreased (P less than .05) sow lactation weight loss. Water drip increased (P less than .002) sow feed intake and reduced lactation weight loss. The drip X floor-type interaction was significant for most measures of piglet performance. Drip was beneficial for piglet weights when piglets were on plastic, whereas drip was detrimental to piglet performance while they were housed on concrete. In Exp. 2, two floor types, drip or no-drip and a high energy-density diet or control diet were examined during heat stress. The high energy-density diet reduced (P less than .01) sow feed intake but provided no measurable increase in piglet performance during heat stress. We conclude that water drip is an effective cooling technique for heat-stressed sows, especially when floors are plastic. Snout coolers, partial concrete slots and high energy-density diets provided only minor benefits to heat-stressed sows and were not of benefit to piglets nursing heat-stressed sows.

Adaptations to Speed Endurance Training in Highly Trained Soccer Players.

PubMed

Nyberg, Michael; Fiorenza, Matteo; Lund, Anders; Christensen, Magnus; Rømer, Tue; Piil, Peter; Hostrup, Morten; Christensen, Peter M; Holbek, Simon; Ravnholt, Thomas; Gunnarsson, Thomas P; Bangsbo, Jens

2016-07-01

The present study examined whether a period of additional speed endurance training would improve intense intermittent exercise performance in highly trained soccer players during the season and whether the training changed aerobic metabolism and the level of oxidative enzymes in type I and type II muscle fibers. During the last 9 wk of the season, 13 semiprofessional soccer players performed additional speed endurance training sessions consisting of two to three sets of 8-10 repetitions of 30-m sprints with 10 s of passive recovery (SET). Before and after SET, subjects completed a double-step exercise protocol that included transitions from standing to moderate-intensity running (~75% HRmax), followed by transitions from moderate- to high-intensity running (~90% HRmax) in which pulmonary oxygen uptake (V˙O2) was determined. In addition, the yo-yo intermittent recovery test level 1 was performed, and a muscle biopsy was obtained at rest. The yo-yo intermittent recovery test level 1 performance was 11.6% ± 6.4% (mean ± SD) better (2803 ± 330 vs 3127 ± 383 m, P < 0.05) after SET compared with before SET. In the transition from standing to moderate-intensity running, phase II pulmonary V˙O2 kinetics was 11.4% ± 16.5% faster (P < 0.05), and the running economy at this intensity was 2.3% ± 3.0% better (P < 0.05). These improvements were apparent despite the content of muscle proteins regulating oxidative metabolism (3-hydroxyacyl CoA dehydrogenase, COX IV, and OXPHOS), and capillarization was reduced (P < 0.05). The content of 3-hydroxyacyl CoA dehydrogenase and citrate synthase in type I and type II fibers did not change. In highly trained soccer players, additional speed endurance training is associated with an improved ability to perform repeated high-intensity work. To what extent the training-induced changes in V˙O2 kinetics and mechanical efficiency in type I fibers caused the improvement in performance warrants further investigation.

Nano-scaled Pt/Ag/Ni/Au contacts on p-type GaN for low contact resistance and high reflectivity.

PubMed

Kwon, Y W; Ju, I C; Kim, S K; Choi, Y S; Kim, M H; Yoo, S H; Kang, D H; Sung, H K; Shin, K; Ko, C G

2011-07-01

We synthesized the vertical-structured LED (VLED) using nano-scaled Pt between p-type GaN and Ag-based reflector. The metallization scheme on p-type GaN for high reflectance and low was the nano-scaled Pt/Ag/Ni/Au. Nano-scaled Pt (5 A) on Ag/Ni/Au exhibited reasonably high reflectance of 86.2% at the wavelength of 460 nm due to high transmittance of light through nano-scaled Pt (5 A) onto Ag layer. Ohmic behavior of contact metal, Pt/Ag/Ni/Au, to p-type GaN was achieved using surface treatments of p-type GaN prior to the deposition of contact metals and the specific contact resistance was observed with decreasing Pt thickness of 5 A, resulting in 1.5 x 10(-4) ohms cm2. Forward voltages of Pt (5 A)/Ag/Ni contact to p-type GaN showed 4.19 V with the current injection of 350 mA. Output voltages with various thickness of Pt showed the highest value at the smallest thickness of Pt due to its high transmittance of light onto Ag, leading to high reflectance. Our results propose that nano-scaled Pt/Ag/Ni could act as a promising contact metal to p-type GaN for improving the performance of VLEDs.

Solution-processed organic thermoelectric materials exhibiting doping-concentration-dependent polarity.

PubMed

Hwang, Sunbin; Potscavage, William J; Yang, Yu Seok; Park, In Seob; Matsushima, Toshinori; Adachi, Chihaya

2016-10-26

Recent progress in conducting polymer-based organic thermoelectric generators (OTEGs) has resulted in high performance due to high Seebeck coefficient, high electrical conductivity (σ), and low thermal conductivity obtained by chemically controlling the materials's redox levels. In addition to improving the properties of individual OTEGs to obtain high performance, the development of solution processes for the fabrication of OTEG modules is necessary to realize large thermoelectric voltage and low-cost mass production. However, the scarcity of good candidates for soluble organic n-type materials limits the use of π-leg module structures consisting of complementary elements of p- and n-type materials because of unbalanced transport coefficients that lead to power losses. In particular, the extremely low σ of n-type materials compared with that of p-type materials is a serious challenge. In this study, poly(pyridinium phenylene) (P(PymPh)) was tested as an n-type semiconductor in solution-processed OTEGs, and the carrier density was controlled by a solution-based chemical doping process using the dopant sodium naphthalenide, a well-known reductant. The electronic structures and doping mechanism of P(PymPh) were explored based on the changes in UV-Vis-IR absorption, ultraviolet photoelectron, and X-ray photoelectron spectra. By controlling the dopant concentration, we demonstrate a maximum n-type power factor of 0.81 μW m -1 K -2 with high σ, and at higher doping concentrations, a switch from n-type to p-type TE operation. This is one of the first cases of a switch in polarity just by increasing the concentration of the reductant and may open a new route for simplified fabrication of complementary organic layers.

Ultralow power complementary inverter circuits using axially doped p- and n-channel Si nanowire field effect transistors.

PubMed

Van, Ngoc Huynh; Lee, Jae-Hyun; Whang, Dongmok; Kang, Dae Joon

2016-06-09

We have successfully synthesized axially doped p- and n-type regions on a single Si nanowire (NW). Diodes and complementary metal-oxide-semiconductor (CMOS) inverter devices using single axial p- and n-channel Si NW field-effect transistors (FETs) were fabricated. We show that the threshold voltages of both p- and n-channel Si NW FETs can be lowered to nearly zero by effectively controlling the doping concentration. Because of the high performance of the p- and n-type Si NW channel FETs, especially with regard to the low threshold voltage, the fabricated NW CMOS inverters have a low operating voltage (<3 V) while maintaining a high voltage gain (∼6) and ultralow static power dissipation (≤0.3 pW) at an input voltage of ±3 V. This result offers a viable way for the fabrication of a high-performance high-density logic circuit using a low-temperature fabrication process, which makes it suitable for flexible electronics.

Highly spectrum-selective ultraviolet photodetector based on p-NiO/n-IGZO thin film heterojunction structure.

PubMed

Li, H K; Chen, T P; Hu, S G; Li, X D; Liu, Y; Lee, P S; Wang, X P; Li, H Y; Lo, G Q

2015-10-19

Ultraviolet photodetector with p-n heterojunction is fabricated by magnetron sputtering deposition of n-type indium gallium zinc oxide (n-IGZO) and p-type nickel oxide (p-NiO) thin films on ITO glass. The performance of the photodetector is largely affected by the conductivity of the p-NiO thin film, which can be controlled by varying the oxygen partial pressure during the deposition of the p-NiO thin film. A highly spectrum-selective ultraviolet photodetector has been achieved with the p-NiO layer with a high conductivity. The results can be explained in terms of the "optically-filtering" function of the NiO layer.

Identification and design principles of low hole effective mass p-type transparent conducting oxides

PubMed Central

Hautier, Geoffroy; Miglio, Anna; Ceder, Gerbrand; Rignanese, Gian-Marco; Gonze, Xavier

2013-01-01

The development of high-performance transparent conducting oxides is critical to many technologies from transparent electronics to solar cells. Whereas n-type transparent conducting oxides are present in many devices, their p-type counterparts are not largely commercialized, as they exhibit much lower carrier mobilities due to the large hole effective masses of most oxides. Here we conduct a high-throughput computational search on thousands of binary and ternary oxides and identify several highly promising compounds displaying exceptionally low hole effective masses (up to an order of magnitude lower than state-of-the-art p-type transparent conducting oxides), as well as wide band gaps. In addition to the discovery of specific compounds, the chemical rationalization of our findings opens new directions, beyond current Cu-based chemistries, for the design and development of future p-type transparent conducting oxides. PMID:23939205

Performance study of double SOI image sensors

NASA Astrophysics Data System (ADS)

Miyoshi, T.; Arai, Y.; Fujita, Y.; Hamasaki, R.; Hara, K.; Ikegami, Y.; Kurachi, I.; Nishimura, R.; Ono, S.; Tauchi, K.; Tsuboyama, T.; Yamada, M.

2018-02-01

Double silicon-on-insulator (DSOI) sensors composed of two thin silicon layers and one thick silicon layer have been developed since 2011. The thick substrate consists of high resistivity silicon with p-n junctions while the thin layers are used as SOI-CMOS circuitry and as shielding to reduce the back-gate effect and crosstalk between the sensor and the circuitry. In 2014, a high-resolution integration-type pixel sensor, INTPIX8, was developed based on the DSOI concept. This device is fabricated using a Czochralski p-type (Cz-p) substrate in contrast to a single SOI (SSOI) device having a single thin silicon layer and a Float Zone p-type (FZ-p) substrate. In the present work, X-ray spectra of both DSOI and SSOI sensors were obtained using an Am-241 radiation source at four gain settings. The gain of the DSOI sensor was found to be approximately three times that of the SSOI device because the coupling capacitance is reduced by the DSOI structure. An X-ray imaging demonstration was also performed and high spatial resolution X-ray images were obtained.

High-Performance Nonvolatile Organic Field-Effect Transistor Memory Based on Organic Semiconductor Heterostructures of Pentacene/P13/Pentacene as Both Charge Transport and Trapping Layers.

PubMed

Li, Wen; Guo, Fengning; Ling, Haifeng; Zhang, Peng; Yi, Mingdong; Wang, Laiyuan; Wu, Dequn; Xie, Linghai; Huang, Wei

2017-08-01

Nonvolatile organic field-effect transistor (OFET) memory devices based on pentacene/ N , N '-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (P13)/pentacene trilayer organic heterostructures have been proposed. The discontinuous n-type P13 embedded in p-type pentacene layers can not only provide electrons in the semiconductor layer that facilitates electron trapping process; it also works as charge trapping sites, which is attributed to the quantum well-like pentacene/P13/pentacene organic heterostructures. The synergistic effects of charge trapping in the discontinuous P13 and the charge-trapping property of the poly(4-vinylphenol) (PVP) layer remarkably improve the memory performance. In addition, the trilayer organic heterostructures have also been successfully applied to multilevel and flexible nonvolatile memory devices. The results provide a novel design strategy to achieve high-performance nonvolatile OFET memory devices and allow potential applications for different combinations of various organic semiconductor materials in OFET memory.

Effect of various types of thermochemical processing of sewage sludges on phosphorus speciation, solubility, and fertilization performance.

PubMed

Steckenmesser, Daniel; Vogel, Christian; Adam, Christian; Steffens, Diedrich

2017-04-01

Sewage sludge has one of the highest phosphorus (P) recovery potentials of all waste materials. Therefore, P-recycling from sewage sludge could contribute to closing the P-cycle. Recently, various thermal processes for P-recovery have been developed, but there is still a demand for information on the effect of different process parameters (e.g. additives and temperature) on P-speciation and especially on the fertilization performance. In the present study, two common methods (low-temperature conversion at 400-500°C and thermochemical treatment at 950°C) were investigated and combined to produce highly bioavailable P-fertilizers from two different types of sewage sludge based on chemical phosphorus precipitation (Chem-P) and enhanced biological phosphorus removal (Bio-P). The results of P-fractionation, X-ray diffraction analysis, and pot experiments with maize showed that Bio-P sludges attain high P-plant-availability after treatment at low temperatures (400°C). In contrast, Chem-P sludges can adequately be treated at higher temperatures under reductive conditions with sodium additives to form highly bioavailable calcium-sodium-phosphate. Additionally, also highly heavy-metal contaminated sludges can be thermochemically treated at high temperatures to achieve the legal requirements for fertilizers. Copyright © 2017 Elsevier Ltd. All rights reserved.

Immediate effects of different types of stretching exercises on badminton jump smash.

PubMed

Jang, Hwi S; Kim, Daeho; Park, Jihong

2018-01-01

Since different types of stretching exercises may alter athletic performance, we compared the effects of three types of stretching exercises on badminton jump smash. Sixteen male collegiate badminton players performed one of three different stretching exercises in a counterbalanced order on different days. Static stretching had seven typical stretches, while dynamic stretching involved nine dynamic movements, and resistance dynamic stretching was performed with weighted vests and dumbbells. Before and after each stretching exercise, subjects performed 20 trials of jump smashes. Dependent measurements were the jump heights during jump smashes, velocities of jump-smashed shuttlecocks, and drop point of jump-smashed shuttlecocks. To test the effects of each stretching exercise, we performed mixed model ANOVAs and calculated between-time effect sizes (ES). Each stretching exercise improved the jump heights during jump smashes (type main effect: F(2,75)=1.19, P=0.31; static stretching: 22.1%, P<0.01, ES=0.98; dynamic stretching: 30.1%, P<0.01, ES=1.49; resistance dynamic stretching: 17.7%, P=0.03, ES=0.98) and velocities of jump-smashed shuttlecocks (type main effect: F(2,75)=2.18, P=0.12; static stretching: 5.7%, P=0.61, ES=0.39; dynamic stretching: 3.4%, P=0.94, ES=0.28; resistance dynamic stretching: 6%, P=0.50, ES=0.66). However, there were no differences among the stretching exercises for any measurement. The drop point of jump-smashed shuttlecocks did not change (interaction: F(2,75)=0.88, P=0.42). All stretching exercises improved badminton jump smash performance, but we could not determine the best protocol. Since badminton requires high-speed movement and explosive force, we suggest performing dynamic stretching or resistance dynamic stretching.

Beetroot Juice Supplementation Improves High-Intensity Intermittent Type Exercise Performance in Trained Soccer Players.

PubMed

Nyakayiru, Jean; Jonvik, Kristin L; Trommelen, Jorn; Pinckaers, Philippe J M; Senden, Joan M; van Loon, Luc J C; Verdijk, Lex B

2017-03-22

It has been shown that nitrate supplementation can enhance endurance exercise performance. Recent work suggests that nitrate ingestion can also increase intermittent type exercise performance in recreational athletes. We hypothesized that six days of nitrate supplementation can improve high-intensity intermittent type exercise performance in trained soccer players. Thirty-two male soccer players (age: 23 ± 1 years, height: 181 ± 1 m, weight: 77 ± 1 kg, playing experience: 15.2 ± 0.5 years, playing in the first team of a 2nd or 3rd Dutch amateur league club) participated in this randomized, double-blind cross-over study. All subjects participated in two test days in which high-intensity intermittent running performance was assessed using the Yo-Yo IR1 test. Subjects ingested nitrate-rich (140 mL; ~800 mg nitrate/day; BR) or a nitrate-depleted beetroot juice (PLA) for six subsequent days, with at least eight days of wash-out between trials. The distance covered during the Yo-Yo IR1 was the primary outcome measure, while heart rate (HR) was measured continuously throughout the test, and a single blood and saliva sample were collected just prior to the test. Six days of BR ingestion increased plasma and salivary nitrate and nitrite concentrations in comparison to PLA ( p < 0.001), and enhanced Yo-Yo IR1 test performance by 3.4 ± 1.3% (from 1574 ± 47 to 1623 ± 48 m; p = 0.027). Mean HR was lower in the BR (172 ± 2) vs. PLA trial (175 ± 2; p = 0.014). Six days of BR ingestion effectively improves high-intensity intermittent type exercise performance in trained soccer players.

Beetroot Juice Supplementation Improves High-Intensity Intermittent Type Exercise Performance in Trained Soccer Players

PubMed Central

Nyakayiru, Jean; Jonvik, Kristin L.; Trommelen, Jorn; Pinckaers, Philippe J. M.; Senden, Joan M.; van Loon, Luc J. C.; Verdijk, Lex B.

2017-01-01

It has been shown that nitrate supplementation can enhance endurance exercise performance. Recent work suggests that nitrate ingestion can also increase intermittent type exercise performance in recreational athletes. We hypothesized that six days of nitrate supplementation can improve high-intensity intermittent type exercise performance in trained soccer players. Thirty-two male soccer players (age: 23 ± 1 years, height: 181 ± 1 m, weight: 77 ± 1 kg, playing experience: 15.2 ± 0.5 years, playing in the first team of a 2nd or 3rd Dutch amateur league club) participated in this randomized, double-blind cross-over study. All subjects participated in two test days in which high-intensity intermittent running performance was assessed using the Yo-Yo IR1 test. Subjects ingested nitrate-rich (140 mL; ~800 mg nitrate/day; BR) or a nitrate-depleted beetroot juice (PLA) for six subsequent days, with at least eight days of wash-out between trials. The distance covered during the Yo-Yo IR1 was the primary outcome measure, while heart rate (HR) was measured continuously throughout the test, and a single blood and saliva sample were collected just prior to the test. Six days of BR ingestion increased plasma and salivary nitrate and nitrite concentrations in comparison to PLA (p < 0.001), and enhanced Yo-Yo IR1 test performance by 3.4 ± 1.3% (from 1574 ± 47 to 1623 ± 48 m; p = 0.027). Mean HR was lower in the BR (172 ± 2) vs. PLA trial (175 ± 2; p = 0.014). Six days of BR ingestion effectively improves high-intensity intermittent type exercise performance in trained soccer players. PMID:28327503

Lanthanide Contraction as a Design Factor for High-Performance Half-Heusler Thermoelectric Materials.

PubMed

Liu, Yintu; Fu, Chenguang; Xia, Kaiyang; Yu, Junjie; Zhao, Xinbing; Pan, Hongge; Felser, Claudia; Zhu, Tiejun

2018-06-25

Forming solid solutions, as an effective strategy to improve thermoelectric performance, has a dilemma that alloy scattering will reduce both the thermal conductivity and carrier mobility. Here, an intuitive way is proposed to decouple the opposite effects, that is, using lanthanide contraction as a design factor to select alloying atoms with large mass fluctuation but small radius difference from the host atoms. Typical half-Heusler alloys, n-type (Zr,Hf)NiSn and p-type (Nb,Ta)FeSb solid solutions, are taken as paradigms to attest the validity of this design strategy, which exhibit greatly suppressed lattice thermal conductivity and maintained carrier mobility. Furthermore, by considering lanthanide contraction, n-type (Zr,Hf)CoSb-based alloys with high zT of ≈1.0 are developed. These results highlight the significance of lanthanide contraction as a design factor in enhancing the thermoelectric performance and reveal the practical potential of (Zr,Hf)CoSb-based half-Heusler compounds due to the matched n-type and p-type thermoelectric performance. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High performance p-type half-Heusler thermoelectric materials

NASA Astrophysics Data System (ADS)

Yu, Junjie; Xia, Kaiyang; Zhao, Xinbing; Zhu, Tiejun

2018-03-01

Half-Heusler compounds, which possess robust mechanical strength, good high temperature thermal stability and multifaceted physical properties, have been verified as a class of promising thermoelectric materials. During the last two decades, great progress has been made in half-Heusler thermoelectrics. In this review, we summarize some representative work of p-type half-Heusler materials, the thermoelectric performance of which has been remarkably enhanced in recent years. We introduce the features of the crystal and electronic structures of half-Heusler compounds, and successful strategies for optimizing electrical and thermal transport in the p-type RFeSb (R  =  V, Nb, Ta) and MCoSb (M  =  Ti, Zr, Hf) based systems, including band engineering, the formation of solid solutions and hierarchical phonon scattering. The outlook for future research directions of half-Heusler thermoelectrics is also presented.

Potential for high thermoelectric performance in n-type Zintl compounds: A case study of Ba doped KAlSb 4

DOE PAGES

Ortiz, Brenden R.; Gorai, Prashun; Krishna, Lakshmi; ...

2017-01-11

High-throughput calculations (first-principles density functional theory and semi-empirical transport models) have the potential to guide the discovery of new thermoelectric materials. Herein we have computationally assessed the potential for thermoelectric performance of 145 complex Zintl pnictides. Of the 145 Zintl compounds assessed, 17% show promising n-type transport properties, compared with only 6% showing promising p-type transport. We predict that n-type Zintl compounds should exhibit high mobility μ n while maintaining the low thermal conductivity κ L typical of Zintl phases. Thus, not only do candidate n-type Zintls outnumber their p-type counterparts, but they may also exhibit improved thermoelectric performance. Frommore » the computational search, we have selected n-type KAlSb 4 as a promising thermoelectric material. Synthesis and characterization of polycrystalline KAlSb 4 reveals non-degenerate n-type transport. With Ba substitution, the carrier concentration is tuned between 10 18 and 10 19 e – cm –3 with a maximum Ba solubility of 0.7% on the K site. High temperature transport measurements confirm a high μ n (50 cm 2 V –1 s –1) coupled with a near minimum κ L (0.5 W m –1 K –1) at 370 °C. Together, these properties yield a zT of 0.7 at 370 °C for the composition K 0.99Ba 0.01AlSb 4. As a result, based on the theoretical predictions and subsequent experimental validation, we find significant motivation for the exploration of n-type thermoelectric performance in other Zintl pnictides.« less

Potential for high thermoelectric performance in n-type Zintl compounds: A case study of Ba doped KAlSb 4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ortiz, Brenden R.; Gorai, Prashun; Krishna, Lakshmi

High-throughput calculations (first-principles density functional theory and semi-empirical transport models) have the potential to guide the discovery of new thermoelectric materials. Herein we have computationally assessed the potential for thermoelectric performance of 145 complex Zintl pnictides. Of the 145 Zintl compounds assessed, 17% show promising n-type transport properties, compared with only 6% showing promising p-type transport. We predict that n-type Zintl compounds should exhibit high mobility μ n while maintaining the low thermal conductivity κ L typical of Zintl phases. Thus, not only do candidate n-type Zintls outnumber their p-type counterparts, but they may also exhibit improved thermoelectric performance. Frommore » the computational search, we have selected n-type KAlSb 4 as a promising thermoelectric material. Synthesis and characterization of polycrystalline KAlSb 4 reveals non-degenerate n-type transport. With Ba substitution, the carrier concentration is tuned between 10 18 and 10 19 e – cm –3 with a maximum Ba solubility of 0.7% on the K site. High temperature transport measurements confirm a high μ n (50 cm 2 V –1 s –1) coupled with a near minimum κ L (0.5 W m –1 K –1) at 370 °C. Together, these properties yield a zT of 0.7 at 370 °C for the composition K 0.99Ba 0.01AlSb 4. As a result, based on the theoretical predictions and subsequent experimental validation, we find significant motivation for the exploration of n-type thermoelectric performance in other Zintl pnictides.« less

Effect of Precede-Proceed Model on Preventive Behaviors for Type 2 Diabetes Mellitus in High-Risk Individuals.

PubMed

Moshki, Mahdi; Dehnoalian, Atefeh; Alami, Ali

2017-04-01

This study sought to assess the effect of precede-proceed model on preventive behaviors for type 2 diabetes mellitus (DM) in high-risk individuals. In this semi-experimental study, 164 high-risk individuals for type 2 DM were selected and were randomly divided into two groups of intervention and control ( n = 85). Educational intervention was performed as a single session face-to-face instruction for 1.5 hr for the intervention group participants. Data were collected before (baseline) and immediately and 1 month after the intervention in the two groups. The mean score of predisposing (knowledge) factors ( p = .001), reinforcing factors ( p = .001), and enabling factors ( p = .02) were significantly different at baseline and 1 month after the intervention in the intervention group compared with the control group ( p < .05). A significant improvement occurred in the nutritional habits of high-risk participants in the intervention group at 1 month after the intervention compared with controls ( p = .001). The precede-proceed model can be effective for promoting the preventive behaviors for type 2 DM in high-risk individuals.

High performance Si nanowire field-effect-transistors based on a CMOS inverter with tunable threshold voltage.

PubMed

Van, Ngoc Huynh; Lee, Jae-Hyun; Sohn, Jung Inn; Cha, Seung Nam; Whang, Dongmok; Kim, Jong Min; Kang, Dae Joon

2014-05-21

We successfully fabricated nanowire-based complementary metal-oxide semiconductor (NWCMOS) inverter devices by utilizing n- and p-type Si nanowire field-effect-transistors (NWFETs) via a low-temperature fabrication processing technique. We demonstrate that NWCMOS inverter devices can be operated at less than 1 V, a significantly lower voltage than that of typical thin-film based complementary metal-oxide semiconductor (CMOS) inverter devices. This low-voltage operation was accomplished by controlling the threshold voltage of the n-type Si NWFETs through effective management of the nanowire (NW) doping concentration, while realizing high voltage gain (>10) and ultra-low static power dissipation (≤3 pW) for high-performance digital inverter devices. This result offers a viable means of fabricating high-performance, low-operation voltage, and high-density digital logic circuits using a low-temperature fabrication processing technique suitable for next-generation flexible electronics.

Characterization of three types of silicon solar cells for SEPS Deep Space Mission. Volume 3: Current-voltage characteristics of spectrolab sculptured BSR/P+ (K7), BSR/P+ (K6.5) and BSR (K4.5) cells as a function of temperature and intensity

NASA Technical Reports Server (NTRS)

Whitaker, A. F.; Little, S. A.; Wooden, V. A.; Carter, D. E.; Cothren, B. E.; Torstenson, C. A.

1980-01-01

Three types of high performance silicon solar cells, sculptured BSR/P+(K7), BSR/P+(K6.5) and BSR(K4.5) manufactured by Spectrolab were evaluated for their low temperature and low intensity performance. Sixteen cells of each type were subjected to 11 temperatures and 9 intensities. The sculptured BSR/P+(K7) cells provided the greatest maximum power output both at 1 AU and at LTLI conditions. The average efficiencies of this cell were 14.4 percent at 1 SC/+25 deg C and 18.5 percent at 0.086 SC/-100 deg C.

High-Performance Near-Infrared Photodetectors Based on p-type SnX (X=S, Se) Nanowires Grown via Chemical Vapor Deposition.

PubMed

Zheng, Dingshan; Fang, Hehai; Long, Mingsheng; Wu, Feng; Wang, Peng; Gong, Fan; Wu, Xing; Ho, Johnny C; Liao, Lei; Hu, Weida

2018-06-21

Because of the distinct electronic properties and strong interaction with light, quasi-one-dimensional nanowires (NWs) with semiconducting property have been demonstrated with tremendous potential for various technological applications, especially electronics and optoelectronics. However, until now, most of the state-of-the-art NW photodetectors are predominantly based on the N-type NW channel. Here, we successfully synthesized P-type SnSe and SnS NWs via chemical vapor deposition method and fabricated high-performance single SnSe and SnS NW photodetectors. Importantly, these two NW devices exhibit the impressive photodetection performance with the high photoconductive gain of 1.5 × 10 4 (2.8 × 10 4 ), good responsivity of 1.0× 10 4 A W -1 (1.6× 10 4 A W -1 ) as well as excellent detectivity of 3.3 × 10 12 Jones (2.4 × 10 12 Jones) under near-infrared illumination at a bias of 3 V for the SnSe NW (SnS NW) channel. The rise and fall times can be as efficient as 460 and 520 μs (1.2 and 15.1 ms), respectively, for the SnSe NW (SnS NW) device. Moreover, the spatially resolved photocurrent mapping of the devices further reveals the bias-dependent photocurrent generation. All these results evidently demonstrate that the P-type SnSe and SnS NWs have great potential to be applied in next-generation high-performance optoelectronic devices.

Chromium Trioxide Hole-Selective Heterocontacts for Silicon Solar Cells.

PubMed

Lin, Wenjie; Wu, Weiliang; Liu, Zongtao; Qiu, Kaifu; Cai, Lun; Yao, Zhirong; Ai, Bin; Liang, Zongcun; Shen, Hui

2018-04-25

A high recombination rate and high thermal budget for aluminum (Al) back surface field are found in the industrial p-type silicon solar cells. Direct metallization on lightly doped p-type silicon, however, exhibits a large Schottky barrier for the holes on the silicon surface because of Fermi-level pinning effect. As a result, low-temperature-deposited, dopant-free chromium trioxide (CrO x , x < 3) with high stability and high performance is first applied in a p-type silicon solar cell as a hole-selective contact at the rear surface. By using 4 nm CrO x between the p-type silicon and Ag, we achieve a reduction of the contact resistivity for the contact of Ag directly on p-type silicon. For further improvement, we utilize a CrO x (2 nm)/Ag (30 nm)/CrO x (2 nm) multilayer film on the contact between Ag and p-type crystalline silicon (c-Si) to achieve a lower contact resistance (40 mΩ·cm 2 ). The low-resistivity Ohmic contact is attributed to the high work function of the uniform CrO x film and the depinning of the Fermi level of the SiO x layer at the silicon interface. Implementing the advanced hole-selective contacts with CrO x /Ag/CrO x on the p-type silicon solar cell results in a power conversion efficiency of 20.3%, which is 0.1% higher than that of the cell utilizing 4 nm CrO x . Compared with the commercialized p-type solar cell, the novel CrO x -based hole-selective transport material opens up a new possibility for c-Si solar cells using high-efficiency, low-temperature, and dopant-free deposition techniques.

High-performance and compact-designed flexible thermoelectric modules enabled by a reticulate carbon nanotube architecture

PubMed Central

Zhou, Wenbin; Fan, Qingxia; Zhang, Qiang; Cai, Le; Li, Kewei; Gu, Xiaogang; Yang, Feng; Zhang, Nan; Wang, Yanchun; Liu, Huaping; Zhou, Weiya; Xie, Sishen

2017-01-01

It is a great challenge to substantially improve the practical performance of flexible thermoelectric modules due to the absence of air-stable n-type thermoelectric materials with high-power factor. Here an excellent flexible n-type thermoelectric film is developed, which can be conveniently and rapidly prepared based on the as-grown carbon nanotube continuous networks with high conductivity. The optimum n-type film exhibits ultrahigh power factor of ∼1,500 μW m−1 K−2 and outstanding stability in air without encapsulation. Inspired by the findings, we design and successfully fabricate the compact-configuration flexible TE modules, which own great advantages compared with the conventional π-type configuration modules and well integrate the superior thermoelectric properties of p-type and n-type carbon nanotube films resulting in a markedly high performance. Moreover, the research results are highly scalable and also open opportunities for the large-scale production of flexible thermoelectric modules. PMID:28337987

Ultra High p-doping Material Research for GaN Based Light Emitters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vladimir Dmitriev

2007-06-30

The main goal of the Project is to investigate doping mechanisms in p-type GaN and AlGaN and controllably fabricate ultra high doped p-GaN materials and epitaxial structures. Highly doped p-type GaN-based materials with low electrical resistivity and abrupt doping profiles are of great importance for efficient light emitters for solid state lighting (SSL) applications. Cost-effective hydride vapor phase epitaxial (HVPE) technology was proposed to investigate and develop p-GaN materials for SSL. High p-type doping is required to improve (i) carrier injection efficiency in light emitting p-n junctions that will result in increasing of light emitting efficiency, (ii) current spreading inmore » light emitting structures that will improve external quantum efficiency, and (iii) parameters of Ohmic contacts to reduce operating voltage and tolerate higher forward currents needed for the high output power operation of light emitters. Highly doped p-type GaN layers and AlGaN/GaN heterostructures with low electrical resistivity will lead to novel device and contact metallization designs for high-power high efficiency GaN-based light emitters. Overall, highly doped p-GaN is a key element to develop light emitting devices for the DOE SSL program. The project was focused on material research for highly doped p-type GaN materials and device structures for applications in high performance light emitters for general illumination P-GaN and p-AlGaN layers and multi-layer structures were grown by HVPE and investigated in terms of surface morphology and structure, doping concentrations and profiles, optical, electrical, and structural properties. Tasks of the project were successfully accomplished. Highly doped GaN materials with p-type conductivity were fabricated. As-grown GaN layers had concentration N{sub a}-N{sub d} as high as 3 x 10{sup 19} cm{sup -3}. Mechanisms of doping were investigated and results of material studies were reported at several International conferences providing better understanding of p-type GaN formation for Solid State Lighting community. Grown p-type GaN layers were used as substrates for blue and green InGaN-based LEDs made by HVPE technology at TDI. These results proved proposed technical approach and facilitate fabrication of highly conductive p-GaN materials by low-cost HVPE technology for solid state lighting applications. TDI has started the commercialization of p-GaN epitaxial materials.« less

Measured Attenuation of Coplanar Waveguide on 6H, p-type SiC and High Purity Semi-Insulating 4H SiC through 800 K

NASA Technical Reports Server (NTRS)

Ponchak, George E.; Schwartz, Zachary D.; Alterovitz, Samuel A.; Downey, Alan N.

2004-01-01

Wireless sensors for high temperature applications such as oil drilling and mining, automobiles, and jet engine performance monitoring require circuits built on wide bandgap semiconductors. In this paper, the characteristics of microwave transmission lines on 4H-High Purity Semi-Insulating SiC and 6H, p-type SiC is presented as a function of temperature and frequency. It is shown that the attenuation of 6H, p-type substrates is too high for microwave circuits, large leakage current will flow through the substrate, and that unusual attenuation characteristics are due to trapping in the SiC. The 4H-HPSI SiC is shown to have low attenuation and leakage currents over the entire temperature range.

Influence of the transition region between p- and n-type polycrystalline silicon passivating contacts on the performance of interdigitated back contact silicon solar cells

NASA Astrophysics Data System (ADS)

Reichel, Christian; Müller, Ralph; Feldmann, Frank; Richter, Armin; Hermle, Martin; Glunz, Stefan W.

2017-11-01

Passivating contacts based on thin tunneling oxides (SiOx) and n- and p-type semi-crystalline or polycrystalline silicon (poly-Si) enable high passivation quality and low contact resistivity, but the integration of these p+/n emitter and n+/n back surface field junctions into interdigitated back contact silicon solar cells poses a challenge due to high recombination at the transition region from p-type to n-type poly-Si. Here, the transition region was created in different configurations—(a) p+ and n+ poly-Si regions are in direct contact with each other ("pn-junction"), using a local overcompensation (counterdoping) as a self-aligning process, (b) undoped (intrinsic) poly-Si remains between the p+ and n+ poly-Si regions ("pin-junction"), and (c) etched trenches separate the p+ and n+ poly-Si regions ("trench")—in order to investigate the recombination characteristics and the reverse breakdown behavior of these solar cells. Illumination- and injection-dependent quasi-steady state photoluminescence (suns-PL) and open-circuit voltage (suns-Voc) measurements revealed that non-ideal recombination in the space charge regions with high local ideality factors as well as recombination in shunted regions strongly limited the performance of solar cells without a trench. In contrast, solar cells with a trench allowed for open-circuit voltage (Voc) of 720 mV, fill factor of 79.6%, short-circuit current (Jsc) of 41.3 mA/cm2, and a conversion efficiencies (η) of 23.7%, showing that a lowly conducting and highly passivating intermediate layer between the p+ and n+ poly-Si regions is mandatory. Independent of the configuration, no hysteresis was observed upon multiple stresses in reverse direction, indicating a controlled and homogeneously distributed breakdown, but with different breakdown characteristics.

P-Doped NiCo2S4 nanotubes as battery-type electrodes for high-performance asymmetric supercapacitors.

PubMed

Lin, Jinghuang; Wang, Yiheng; Zheng, Xiaohang; Liang, Haoyan; Jia, Henan; Qi, Junlei; Cao, Jian; Tu, Jinchun; Fei, Weidong; Feng, Jicai

2018-06-19

NiCo2S4 is a promising electrode material for supercapacitors, due to its rich redox reactions and intrinsically high conductivity. Unfortunately, in most cases, NiCo2S4-based electrodes often suffer from low specific capacitance, low rate capability and fast capacitance fading. Herein, we have rationally designed P-doped NiCo2S4 nanotube arrays to improve the electrochemical performance through a phosphidation reaction. Characterization results demonstrate that the P element is successfully doped into NiCo2S4 nanotube arrays. Electrochemical results demonstrate that P-doped NiCo2S4 nanotube arrays exhibit better electrochemical performance than pristine NiCo2S4, e.g. higher specific capacitance (8.03 F cm-2 at 2 mA cm-2), good cycling stability (87.5% capacitance retention after 5000 cycles), and lower charge transfer resistance. More importantly, we also assemble an asymmetric supercapacitor using P-doped NiCo2S4 nanotube arrays and activated carbon on carbon cloth, which delivers a maximum energy density of 42.1 W h kg-1 at a power density of 750 W kg-1. These results demonstrate that the as-fabricated P-doped NiCo2S4 nanotube arrays on carbon cloth show great potential as a battery-type electrode for high-performance supercapacitors.

Ultrahigh-sensitive sensing platform based on p-type dumbbell-like Co3O4 network

NASA Astrophysics Data System (ADS)

Zhou, Tingting; Zhang, Tong; Zhang, Rui; Lou, Zheng; Deng, Jianan; Wang, Lili

2017-12-01

Development of high performance room temperature sensors remains a grand challenge for high demand of practical application. Metal oxide semiconductors (MOSs) have many advantages over others due to their easy functionalization, high surface area, and low cost. However, they typically need a high work temperature during sensing process. Here, p-type sensing layer is reported, consisting of pore-rich dumbbell-like Co3O4 particles (DP-Co3O4) with intrinsic high catalytic activity. The gas sensor (GS) based DP-Co3O4 catalyst exhibits ultrahigh NH3 sensing activity along with excellent stability over other structure based NH3 GSs in room temperature work environment. In addition, the unique structure of DP-Co3O4 with pore-rich and high catalytic activity endows fast gas diffusion rate and high sensitivity at room temperature. Taken together, the findings in this work highlight the merit of integrating highly active materials in p-type materials, offering a framework to develop high-sensitivity room temperature sensing platforms.

Method for manufacturing compound semiconductor field-effect transistors with improved DC and high frequency performance

DOEpatents

Zolper, John C.; Sherwin, Marc E.; Baca, Albert G.

2000-01-01

A method for making compound semiconductor devices including the use of a p-type dopant is disclosed wherein the dopant is co-implanted with an n-type donor species at the time the n-channel is formed and a single anneal at moderate temperature is then performed. Also disclosed are devices manufactured using the method. In the preferred embodiment n-MESFETs and other similar field effect transistor devices are manufactured using C ions co-implanted with Si atoms in GaAs to form an n-channel. C exhibits a unique characteristic in the context of the invention in that it exhibits a low activation efficiency (typically, 50% or less) as a p-type dopant, and consequently, it acts to sharpen the Si n-channel by compensating Si donors in the region of the Si-channel tail, but does not contribute substantially to the acceptor concentration in the buried p region. As a result, the invention provides for improved field effect semiconductor and related devices with enhancement of both DC and high-frequency performance.

Delta-doping optimization for high quality p-type GaN

NASA Astrophysics Data System (ADS)

Bayram, C.; Pau, J. L.; McClintock, R.; Razeghi, M.

2008-10-01

Delta (δ -) doping is studied in order to achieve high quality p-type GaN. Atomic force microscopy, x-ray diffraction, photoluminescence, and Hall measurements are performed on the samples to optimize the δ-doping characteristics. The effect of annealing on the electrical, optical, and structural quality is also investigated for different δ-doping parameters. Optimized pulsing conditions result in layers with hole concentrations near 1018 cm-3 and superior crystal quality compared to conventional p-GaN. This material improvement is achieved thanks to the reduction in the Mg activation energy and self-compensation effects in δ-doped p-GaN.

Influence of defects and dopants on the photovoltaic performance of Bi 2S 3: First-principles insights

DOE PAGES

Han, Dan; Du, Mao -Hua; Dai, Chen -Min; ...

2017-02-23

Bi 2S 3 has attracted extensive attention recently as a light-absorber, sensitizer or electron acceptor material in various solar cells. Using first-principles calculations, we find that the photovoltaic efficiency of Bi 2S 3 solar cells is limited by its intrinsic point defects, i.e., both S vacancy and S interstitial can have high concentration and produce deep defect levels in the bandgap, leading to non-radiative recombination of electron–hole carriers and reduced minority carrier lifetime. Unexpectedly most of the intrinsic defects in Bi 2S 3, including even the S interstitial, act as donor defects, explaining the observed n-type conductivity and also causingmore » the high p-type conductivity impossible thermodynamically. Doping in Bi 2S 3 by a series of extrinsic elements is studied, showing that most of the dopant elements such as Cu, Br and Cl make the material even more n-type and only Pb doping makes it weakly p-type. Based on this, we propose that the surface region of n-type Bi 2S 3 nanocrystals in p-PbS/n-Bi 2S 3 nano-heterojunction solar cells may be type-inverted into p-type due to Pb doping, with a buried p–n junction formed in the Bi 2S 3 nanocrystals, which provides a new explanation to the longer carrier lifetime and higher efficiency. Lastly, considering the relatively low conduction band and high n-type conductivity, we predict that Cu, Br and Cl doped Bi 2S 3 may be an ideal n-type electron acceptor or counter electrode material, while the performance of Bi 2S 3 as a light-absorber or sensitizer material is intrinsically limited.« less

Multimarker Strategy for Heart Failure Prognostication. Value of Neurohormonal Biomarkers: Neprilysin vs NT-proBNP.

PubMed

Bayes-Genis, Antoni; Barallat, Jaume; Galán, Amparo; de Antonio, Marta; Domingo, Mar; Zamora, Elisabet; Gastelurrutia, Paloma; Vila, Joan; Peñafiel, Judith; Gálvez-Montón, Carolina; Lupón, Josep

2015-12-01

Neprilysin breaks down numerous vasoactive peptides. The soluble form of neprilysin, which was recently identified in heart failure, is associated with cardiovascular outcomes. Within a multibiomarker strategy, we directly compared soluble neprilysin and N-terminal pro-B-type natriuretic peptide as risk stratifiers in a real-life cohort of heart failure patients. Soluble neprilysin, N-terminal pro-B-type natriuretic peptide, ST2, and high-sensitivity troponin T levels were measured in 797 consecutive ambulatory heart failure patients followed up for 4.7 years. Comprehensive multivariable analyses and soluble neprilysin vs N-terminal pro-B-type natriuretic peptide head-to-head assessments of performance were performed. A primary composite endpoint included cardiovascular death or heart failure hospitalization. A secondary endpoint explored cardiovascular death alone. Median soluble neprilysin and N-terminal pro-B-type natriuretic peptide concentrations were 0.64ng/mL and 1187 ng/L, respectively. Both biomarkers significantly correlated with age (P<.001) and ST2 (P<.001), but only N-terminal pro-B-type natriuretic peptide significantly correlated with estimated glomerular filtration rate (P<.001), body mass index (P<.001), left ventricular ejection fraction (P=.02) and high-sensitivity troponin T (P<.001). In multivariable Cox regression analyses, soluble neprilysin remained independently associated with the composite endpoint (hazard ratio=1.14; 95% confidence interval, 1.02-1.27; P=.03) and cardiovascular death (hazard ratio=1.15; 95% confidence interval, 1.01-1.31; P=.04), but N-terminal pro-B-type natriuretic peptide did not. The head-to-head soluble neprilysin vs N-terminal pro-B-type natriuretic peptide comparison showed good calibration and similar discrimination and reclassification for both neurohormonal biomarkers, but only soluble neprilysin improved overall goodness-of-fit. When added to a multimarker strategy, soluble neprilysin remained an independent prognosticator, while N-terminal pro-B-type natriuretic peptide lost significance as a risk stratifier in ambulatory patients with heart failure. Both biomarkers performed similarly in head-to-head analyses. Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Synthesis of p-type ZnO films

NASA Astrophysics Data System (ADS)

Ryu, Y. R.; Zhu, S.; Look, D. C.; Wrobel, J. M.; Jeong, H. M.; White, H. W.

2000-06-01

p-Type ZnO obtained by arsenic (As) doping is reported for the first time. Arsenic-doped ZnO (ZnO : As) films have been deposited on (0 0 1)-GaAs substrates by pulsed laser ablation. The process of synthesizing p-type ZnO : As films was performed in an ambient gas of ultra-pure (99.999%) oxygen. The ambient gas pressure was 35 mTorr with the substrate temperature in the range 300-450°C. ZnO films grown at 400°C and 450°C are p-type and As is a good acceptor. The acceptor peak is located at 3.32 eV and its binding energy is about 100 meV. Acceptor concentrations of As atoms in ZnO films were in the range from high 10 17 to high 10 21 atoms/cm 3 as determined by secondary ion mass spectroscopy (SIMS) and Hall effect measurements.

Silicon solar cell development and radiation effects study for low temperature and low illumination intensity operation, volume 2

NASA Technical Reports Server (NTRS)

Kirkpatrick, A. R.

1972-01-01

The results are presented of a study to determine the effect of in-situ proton irradiation upon low temperature, low intensity performance of several cell types. The cell types were selected in an attempt to distinguish variations in temperature-dependent radiation resistance which could be attributed to the n-p or p-n structure, diffused or implanted junctions, crucible grown or float-zone type base material, and high or low base resistivity. The results indicate that while expected variations of performance occur at room temperature, all cell types degrade more or less similarly at lower temperatures with normalized degradation becoming increasingly rapid as temperature is reduced. Recommendations for an optimized cell for Jupiter probe use are included along with a definition of the testing required on these cells to insure good performance characteristics.

Misfit layered Ca{sub 3}Co{sub 4}O{sub 9} as a high figure of merit p-type transparent conducting oxide film through solution processing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aksit, M.; Kolli, S. K.; Slauch, I. M.

Ca{sub 3}Co{sub 4}O{sub 9} thin films synthesized through solution processing are shown to be high-performing, p-type transparent conducting oxides (TCOs). The synthesis method is a cost-effective and scalable process that consists of sol-gel chemistry, spin coating, and heat treatments. The process parameters can be varied to produce TCO thin films with sheet resistance as low as 5.7 kΩ/sq (ρ ≈ 57 mΩ cm) or with average visible range transparency as high as 67%. The most conductive Ca{sub 3}Co{sub 4}O{sub 9} TCO thin film has near infrared region optical transmission as high as 85%. The figure of merit (FOM) for the top-performing Ca{sub 3}Co{submore » 4}O{sub 9} thin film (151 MΩ{sup −1}) is higher than FOM values reported in the literature for all other solution processed, p-type TCO thin films and higher than most others prepared by physical vapor deposition and chemical vapor deposition. Transparent conductivity in misfit layered oxides presents new opportunities for TCO compositions.« less

Highly Flexible Freestanding Porous Carbon Nanofibers for Electrodes Materials of High-Performance All-Carbon Supercapacitors.

PubMed

Liu, Ying; Zhou, Jinyuan; Chen, Lulu; Zhang, Peng; Fu, Wenbin; Zhao, Hao; Ma, Yufang; Pan, Xiaojun; Zhang, Zhenxing; Han, Weihua; Xie, Erqing

2015-10-28

Highly flexible porous carbon nanofibers (P-CNFs) were fabricated by electrospining technique combining with metal ion-assistant acid corrosion process. The resultant fibers display high conductivity and outstanding mechanical flexibility, whereas little change in their resistance can be observed under repeatedly bending, even to 180°. Further results indicate that the improved flexibility of P-CNFs can be due to the high graphitization degree caused by Co ions. In view of electrode materials for high-performance supercapacitors, this type of porous nanostructure and high graphitization degree could synergistically facilitate the electrolyte ion diffusion and electron transportation. In the three electrodes testing system, the resultant P-CNFs electrodes can exhibit a specific capacitance of 104.5 F g(-1) (0.2 A g(-1)), high rate capability (remain 56.5% at 10 A g(-1)), and capacitance retention of ∼94% after 2000 cycles. Furthermore, the assembled symmetric supercapacitors showed a high flexibility and can deliver an energy density of 3.22 Wh kg(-1) at power density of 600 W kg(-1). This work might open a way to improve the mechanical properties of carbon fibers and suggests that this type of freestanding P-CNFs be used as effective electrode materials for flexible all-carbon supercapacitors.

Effect of high fluence neutron irradiation on transport properties of thermoelectrics

NASA Astrophysics Data System (ADS)

Wang, H.; Leonard, K. J.

2017-07-01

Thermoelectric materials were subjected to high fluence neutron irradiation in order to understand the effect of radiation damage on transport properties. This study is relevant to the NASA Radioisotope Thermoelectric Generator (RTG) program in which thermoelectric elements are exposed to radiation over a long period of time in space missions. Selected n-type and p-type bismuth telluride materials were irradiated at the High Flux Isotope Reactor with a neutron fluence of 1.3 × 1018 n/cm2 (E > 0.1 MeV). The increase in the Seebeck coefficient in the n-type material was partially off-set by an increase in electrical resistivity, making the power factor higher at lower temperatures. For the p-type materials, although the Seebeck coefficient was not affected by irradiation, electrical resistivity decreased slightly. The figure of merit, zT, showed a clear drop in the 300-400 K range for the p-type material and an increase for the n-type material. Considering that the p-type and n-type materials are connected in series in a module, the overall irradiation damages at the device level were limited. These results, at neutron fluences exceeding a typical space mission, are significant to ensure that the radiation damage to thermoelectrics does not affect the performance of RTGs.

A high-performance complementary inverter based on transition metal dichalcogenide field-effect transistors.

PubMed

Cho, Ah-Jin; Park, Kee Chan; Kwon, Jang-Yeon

2015-01-01

For several years, graphene has been the focus of much attention due to its peculiar characteristics, and it is now considered to be a representative 2-dimensional (2D) material. Even though many research groups have studied on the graphene, its intrinsic nature of a zero band-gap, limits its use in practical applications, particularly in logic circuits. Recently, transition metal dichalcogenides (TMDs), which are another type of 2D material, have drawn attention due to the advantage of having a sizable band-gap and a high mobility. Here, we report on the design of a complementary inverter, one of the most basic logic elements, which is based on a MoS2 n-type transistor and a WSe2 p-type transistor. The advantages provided by the complementary metal-oxide-semiconductor (CMOS) configuration and the high-performance TMD channels allow us to fabricate a TMD complementary inverter that has a high-gain of 13.7. This work demonstrates the operation of the MoS2 n-FET and WSe2 p-FET on the same substrate, and the electrical performance of the CMOS inverter, which is based on a different driving current, is also measured.

Performance enhancement of GaN ultraviolet avalanche photodiodes with p-type δ-doping

NASA Astrophysics Data System (ADS)

Bayram, C.; Pau, J. L.; McClintock, R.; Razeghi, M.

2008-06-01

High quality δ-doped p-GaN is used as a means of improving the performance of back-illuminated GaN avalanche photodiodes (APDs). Devices with δ-doped p-GaN show consistently lower leakage current and lower breakdown voltage than those with bulk p-GaN. APDs with δ-doped p-GaN also achieve a maximum multiplication gain of 5.1×104, more than 50 times higher than that obtained in devices with bulk p-GaN. The better device performance of APDs with δ-doped p-GaN is attributed to the higher structural quality of the p-GaN layer achieved via δ-doping.

Hybrid phototransistors based on bulk heterojunction films of poly(3-hexylthiophene) and zinc oxide nanoparticle.

PubMed

Nam, Sungho; Seo, Jooyeok; Park, Soohyeong; Lee, Sooyong; Jeong, Jaehoon; Lee, Hyena; Kim, Hwajeong; Kim, Youngkyoo

2013-02-01

Hybrid phototransistors (HPTRs) were fabricated on glass substrates using organic/inorganic hybrid bulk heterojunction films of p-type poly(3-hexylthiophene) (P3HT) and n-type zinc oxide nanoparticles (ZnO(NP)). The content of ZnO(NP) was varied up to 50 wt % in order to understand the composition effect of ZnO(NP) on the performance of HPTRs. The morphology and nanostructure of the P3HT:ZnO(NP) films was examined by employing high resolution electron microscopes and synchrotron radiation grazing angle X-ray diffraction system. The incident light intensity (P(IN)) was varied up to 43.6 μW/cm², whereas three major wavelengths (525 nm, 555 nm, 605 nm) corresponded to the optical absorption of P3HT were applied. Results showed that the present HPTRs showed typical p-type transistor performance even though the n-type ZnO(NP) content increased up to 50 wt %. The highest transistor performance was obtained at 50 wt %, whereas the lowest performance was measured at 23 wt % because of the immature bulk heterojunction morphology. The drain current (I(D)) was proportionally increased with P(IN) due to the photocurrent generation in addition to the field-effect current. The highest apparent and corrected responsivities (R(A) = 4.7 A/W and R(C) = 2.07 A/W) were achieved for the HPTR with the P3HT:ZnO(NP) film (50 wt % ZnO(NP)) at P(IN) = 0.27 μW/cm² (555 nm).

Formation of definite GaN p-n junction by Mg-ion implantation to n--GaN epitaxial layers grown on a high-quality free-standing GaN substrate

NASA Astrophysics Data System (ADS)

Oikawa, Takuya; Saijo, Yusuke; Kato, Shigeki; Mishima, Tomoyoshi; Nakamura, Tohru

2015-12-01

P-type conversion of n--GaN by Mg-ion implantation was successfully performed using high quality GaN epitaxial layers grown on free-standing low-dislocation-density GaN substrates. These samples showed low-temperature PL spectra quite similar to those observed from Mg-doped MOVPE-grown p-type GaN, consisting of Mg related donor-acceptor pair (DAP) and acceptor bound exciton (ABE) emission. P-n diodes fabricated by the Mg-ion implantation showed clear rectifying I-V characteristics and UV and blue light emissions were observed at forward biased conditions for the first time.

Electrical and optical performance of midwave infrared InAsSb heterostructure detectors

NASA Astrophysics Data System (ADS)

Gomółka, Emilia; Kopytko, Małgorzata; Markowska, Olga; Michalczewski, Krystian; Kubiszyn, Łukasz; Kębłowski, Artur; Jureńczyk, Jarosław; Gawron, Waldemar; Martyniuk, Piotr Marcin; Piotrowski, Józef; Rutkowski, Jarosław; Rogalski, Antoni

2018-02-01

We investigate the high-operating temperature performance of InAsSb/AlSb heterostructure detectors with cutoff wavelengths near 5 μm at 230 K. The devices have been fabricated with different types of absorbing layers: nominally undoped absorber (with n-type conductivity), and both n- and p-type doped. The results show that the device performance strongly depends on absorber layer type. Generally, the p-type absorber provides higher values of current responsivity than the n-type absorber, but at the same time also higher values of dark current. The device with the nominally undoped absorbing layer shows moderate values of both current responsivity and dark current. Resulting detectivities D * of nonimmersed devices vary from 2 × 109 to 5 × 109 cm Hz1/2 W ? 1 at 230 K, which is easily achievable with a two-stage thermoelectric cooler. Optical immersion increases the detectivity up to 5 × 1010 cm Hz1/2 W ? 1.

Remote p-type Doping in GaSb/InAs Core-shell Nanowires

PubMed Central

Ning, Feng; Tang, Li-Ming; Zhang, Yong; Chen, Ke-Qiu

2015-01-01

By performing first-principles calculation, we investigated the electronic properties of remotely p-type doping GaSb nanowire by a Zn-doped InAs shell. The results show that for bare zinc-blende (ZB) [111] GaSb/InAs core-shell nanowire the Zn p-type doped InAs shell donates free holes to the non-doped GaSb core nanowire without activation energy, significantly increasing the hole density and mobility of nanowire. For Zn doping in bare ZB [110] GaSb/InAs core-shell nanowire the hole states are compensated by surface states. We also studied the behaviors of remote p-type doing in two-dimensional (2D) GaSb/InAs heterogeneous slabs, and confirmed that the orientation of nanowire side facet is a key factor for achieving high efficient remote p-type doping. PMID:26028535

Temperature-dependent thermal and thermoelectric properties of n -type and p -type S c1 -xM gxN

NASA Astrophysics Data System (ADS)

Saha, Bivas; Perez-Taborda, Jaime Andres; Bahk, Je-Hyeong; Koh, Yee Rui; Shakouri, Ali; Martin-Gonzalez, Marisol; Sands, Timothy D.

2018-02-01

Scandium Nitride (ScN) is an emerging rocksalt semiconductor with octahedral coordination and an indirect bandgap. ScN has attracted significant attention in recent years for its potential thermoelectric applications, as a component material in epitaxial metal/semiconductor superlattices, and as a substrate for defect-free GaN growth. Sputter-deposited ScN thin films are highly degenerate n -type semiconductors and exhibit a large thermoelectric power factor of ˜3.5 ×10-3W /m -K2 at 600-800 K. Since practical thermoelectric devices require both n- and p-type materials with high thermoelectric figures-of-merit, development and demonstration of highly efficient p-type ScN is extremely important. Recently, the authors have demonstrated p-type S c1 -xM gxN thin film alloys with low M gxNy mole-fractions within the ScN matrix. In this article, we demonstrate temperature dependent thermal and thermoelectric transport properties, including large thermoelectric power factors in both n- and p-type S c1 -xM gxN thin film alloys at high temperatures (up to 850 K). Employing a combination of temperature-dependent Seebeck coefficient, electrical conductivity, and thermal conductivity measurements, as well as detailed Boltzmann transport-based modeling analyses of the transport properties, we demonstrate that p-type S c1 -xM gxN thin film alloys exhibit a maximum thermoelectric power factor of ˜0.8 ×10-3W /m -K2 at 850 K. The thermoelectric properties are tunable by adjusting the M gxNy mole-fraction inside the ScN matrix, thereby shifting the Fermi energy in the alloy films from inside the conduction band in case of undoped n -type ScN to inside the valence band in highly hole-doped p -type S c1 -xM gxN thin film alloys. The thermal conductivities of both the n- and p-type films were found to be undesirably large for thermoelectric applications. Thus, future work should address strategies to reduce the thermal conductivity of S c1 -xM gxN thin-film alloys, without affecting the power factor for improved thermoelectric performance.

Application of Karasek's demand/control model a Canadian occupational setting including shift workers during a period of reorganization and downsizing.

PubMed

Schechter, J; Green, L W; Olsen, L; Kruse, K; Cargo, M

1997-01-01

To apply Karasek's Job Content Model to an analysis of the relationships between job type and perceived stress and stress behaviors in a large company during a period of reorganization and downsizing. Cross-sectional mail-out, mail-back survey. A large Canadian telephone/telecommunications company. Stratified random sample (stratified by job category) of 2200 out of 13,000 employees with a response rate of 48.8%. Responses to 25 of Karasek's core questions were utilized to define four job types: low-demand and high control = "relaxed"; high demand and high control = "active"; low demand and low control = "passive", and high demand and low control = "high strain." These job types were compared against self-reported stress levels, perceived general level of health, absenteeism, alcohol use, exercise level, and use of medications and drugs. Similar analyses were performed to assess the influence of shift work. Employees with "passive" or "high strain" job types reported higher levels of stress (trend test p < .0001); poorer health (trend test P = .006); and higher levels of absenteeism (trend test p < .0001). More shift workers reported themselves in poor or fair health (chi-square p = .018) and reported high levels of stress at home (chi-square p = .002) than nonshift workers. The relationships between job type and levels of stress, health and absenteeism, however, held for nonshift workers as well. Job types with high demand and low control were associated with increased stress, increased absenteeism, and poorer self-concept of health. The demand/control model of Karasek and Theorell was validated in this setting with respect to stress and some stress-associated attitudes and behaviors.

Electrical and optical performance of mid-wavelength infrared InAsSb heterostructure detectors

NASA Astrophysics Data System (ADS)

Gomółka, Emilia; Kopytko, Małgorzata; Michalczewski, Krystian; Kubiszyn, Łukasz; Kebłowski, Artur; Gawron, Waldemar; Martyniuk, Piotr; Piotrowski, Józef; Rutkowski, Jarosław

2017-10-01

In this work we investigate the high-operating temperature performance of InAsSb/AlSb heterostructure detectors with cut-off wavelengths near 5 μm at 230 K. The devices have been fabricated with different type of the absorbing layer: nominally undoped absorber, and both n- and p-type doped. The results show that the device performance strongly depends on absorber layer doping. Generally, p-type absorber provides higher values of current responsivity than n-type absorber, but at the same time also higher values of dark current. The device with nominally undoped absorbing layer shows moderate values of both current responsivity and dark current. Resulting detectivities D° of non-immersed devices varies from 2×109 to 7×109 cmHz1/2/W at 230 K, which is easily achievable with a two stage thermoelectric cooler.

Functional pools of oxidative and glycolytic fibers in human muscle observed by 31P magnetic resonance spectroscopy during exercise.

PubMed Central

Park, J H; Brown, R L; Park, C R; McCully, K; Cohn, M; Haselgrove, J; Chance, B

1987-01-01

Quantitative probing of heterogeneous regions in muscle is feasible with phosphorus-31 magnetic resonance spectroscopy because of the differentiation of metabolic patterns of glycolytic and oxidative fibers. A differential recruitment of oxidative and glycolytic fibers during exercise was demonstrated in 4 of 10 untrained young men by following changes in phosphate metabolites. Concentrations of inorganic phosphate (Pi), phosphocreatine, and ATP were estimated in the wrist flexor muscles of the forearm at rest, during two cycles of three grades of exercise, and in recovery. At high work levels (40% of maximum strength), two distinct Pi peaks were observed and identified with Pi pools at pH 6.9 and pH 5.9-6.4, respectively. These could be accounted for as follows. At the lowest level of work (using 20% of maximum strength), early recruitment primarily of oxidative (type I) and possibly some intermediate (type IIA) muscle fibers occurs with relatively little net lactate production and consequently little decrease in pH. At higher work loads, however, primarily glycolytic (type IIB) muscle fibers are recruited, which have relatively high net lactate production and therefore generate a second pool of Pi at low pH. ATP depletion (35-54%) and Pi losses accompanied the reduction in ability to perform during the first exercise cycle. When the cycle of graded exercise was repeated immediately, the total Pi remained high but gave rise to only one peak at pH 6.8-7.0. These observations indicated exhaustion of glycolytic type IIB fibers, removal of lactate by high local blood flow, and sustained contractions largely by oxidative type I and IIA fibers. A functional differentiation of fiber types could also be demonstrated during recovery if exercise was stopped while two pools of Pi were still apparent. In the first 3 min of recovery, the Pi peak at pH 6.8-6.9 disappeared almost entirely, whereas the Pi peak at pH 6.0 remained unaltered, reflecting the faster recovery of oxidative type I fibers. The potential of magnetic resonance spectroscopy to characterize oxidative and glycolytic fibers, predict capacity for aerobic performance, and signal the presence of muscle pathology is discussed. PMID:3480522

Photo-induced surface modification to improve the performance of lead sulfide quantum dot solar cell.

PubMed

Tulsani, Srikanth Reddy; Rath, Arup Kumar

2018-07-15

The solution-processed quantum dot (QD) solar cell technology has seen significant advancements in recent past to emerge as a potential contender for the next generation photovoltaic technology. In the development of high performance QD solar cell, the surface ligand chemistry has played the important role in controlling the doping type and doping density of QD solids. For instance, lead sulfide (PbS) QDs which is at the forefront of QD solar cell technology, can be made n-type or p-type respectively by using iodine or thiol as the surfactant. The advancements in surface ligand chemistry enable the formation of p-n homojunction of PbS QDs layers to attain high solar cell performances. It is shown here, however, that poor Fermi level alignment of thiol passivated p-type PbS QD hole transport layer with the n-type PbS QD light absorbing layer has rendered the photovoltaic devices from realizing their full potential. Here we develop a control surface oxidation technique using facile ultraviolet ozone treatment to increase the p-doping density in a controlled fashion for the thiol passivated PbS QD layer. This subtle surface modification tunes the Fermi energy level of the hole transport layer to deeper values to facilitate the carrier extraction and voltage generation in photovoltaic devices. In photovoltaic devices, the ultraviolet ozone treatment resulted in the average gain of 18% in the power conversion efficiency with the highest recorded efficiency of 8.98%. Copyright © 2018 Elsevier Inc. All rights reserved.

Effects of overgrown p-layer on the emission characteristics of the InGaN/GaN quantum wells in a high-indium light-emitting diode.

PubMed

Chen, Chih-Yen; Hsieh, Chieh; Liao, Che-Hao; Chung, Wei-Lun; Chen, Hao-Tsung; Cao, Wenyu; Chang, Wen-Ming; Chen, Horng-Shyang; Yao, Yu-Feng; Ting, Shao-Ying; Kiang, Yean-Woei; Yang, Chih-Chung C C; Hu, Xiaodong

2012-05-07

The counteraction between the increased carrier localization effect due to the change of composition nanostructure in the quantum wells (QWs), which is caused by the thermal annealing process, and the enhanced quantum-confined Stark effect in the QWs due to the increased piezoelectric field, which is caused by the increased p-type layer thickness, when the p-type layer is grown at a high temperature on the InGaN/GaN QWs of a high-indium light-emitting diode (LED) is demonstrated. Temperature- and excitation power-dependent photoluminescence (PL) measurements are performed on three groups of sample, including 1) the samples with both effects of thermal annealing and increased p-type thickness, 2) those only with the similar thermal annealing process, and 3) those with increased overgrowth thickness and minimized thermal annealing effect. From the comparisons of emission wavelength, internal quantum efficiency (IQE), spectral shift with increasing PL excitation level, and calibrated activation energy of carrier localization between various samples in the three groups, one can clearly see the individual effects of thermal annealing and increased p-type layer thickness. The counteraction leads to increased IQE and blue-shifted emission spectrum with increasing p-type thickness when the thickness is below a certain value (20-nm p-AlGaN plus 60-nm p-GaN under our growth conditions). Beyond this thickness, the IQE value decreases and the emission spectrum red shifts with increasing p-type thickness.

Electronic structure and thermoelectric performance of Zintl compound Sr{sub 3}GaSb{sub 3}: A first-principles study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feng Shi, Qing; Li Yan, Yu; Xu Wang, Yuan, E-mail: wangyx@henu.edu.cn

2014-01-06

By using first-principles method and Boltzmann theory, we simulated the thermoelectric transport properties of p-type and n-type Sr{sub 3}GaSb{sub 3}. It is found that the thermoelectric figure-of merit (ZT) of n-type Sr{sub 3}GaSb{sub 3} is probably better than that of p-type, mainly due to its large band degeneracy. Moreover, a high ZT value of 1.74 at 850 K can be achieved for n-type Sr{sub 3}GaSb{sub 3} along the yy direction, corresponding to the carrier concentration 3.5 × 10{sup 20} e cm{sup −3}. We propose that the high ZT value of experimentally synthesized p-type Sr{sub 3}GaSb{sub 3} is originated from appearing of the larger numbermore » of band valley on the top of valence bands.« less

Aerosol jet printed p- and n-type electrolyte-gated transistors with a variety of electrode materials: exploring practical routes to printed electronics.

PubMed

Hong, Kihyon; Kim, Se Hyun; Mahajan, Ankit; Frisbie, C Daniel

2014-11-12

Printing electrically functional liquid inks is a promising approach for achieving low-cost, large-area, additive manufacturing of flexible electronic circuits. To print thin-film transistors, a basic building block of thin-film electronics, it is important to have several options for printable electrode materials that exhibit high conductivity, high stability, and low-cost. Here we report completely aerosol jet printed (AJP) p- and n-type electrolyte-gated transistors (EGTs) using a variety of different electrode materials including highly conductive metal nanoparticles (Ag), conducting polymers (polystyrenesulfonate doped poly(3,4-ethylendedioxythiophene, PEDOT:PSS), transparent conducting oxides (indium tin oxide), and carbon-based materials (reduced graphene oxide). Using these source-drain electrode materials and a PEDOT:PSS/ion gel gate stack, we demonstrated all-printed p- and n-type EGTs in combination with poly(3-hexythiophene) and ZnO semiconductors. All transistor components (including electrodes, semiconductors, and gate insulators) were printed by AJP. Both kinds of devices showed typical p- and n-type transistor characteristics, and exhibited both low-threshold voltages (<2 V) and high hole and electron mobilities. Our assessment suggests Ag electrodes may be the best option in terms of overall performance for both types of EGTs.

Selective Conversion from p-Type to n-Type of Printed Bottom-Gate Carbon Nanotube Thin-Film Transistors and Application in Complementary Metal-Oxide-Semiconductor Inverters.

PubMed

Xu, Qiqi; Zhao, Jianwen; Pecunia, Vincenzo; Xu, Wenya; Zhou, Chunshan; Dou, Junyan; Gu, Weibing; Lin, Jian; Mo, Lixin; Zhao, Yanfei; Cui, Zheng

2017-04-12

The fabrication of printed high-performance and environmentally stable n-type single-walled carbon nanotube (SWCNT) transistors and their integration into complementary (i.e., complementary metal-oxide-semiconductor, CMOS) circuits are widely recognized as key to achieving the full potential of carbon nanotube electronics. Here, we report a simple, efficient, and robust method to convert the polarity of SWCNT thin-film transistors (TFTs) using cheap and readily available ethanolamine as an electron doping agent. Printed p-type bottom-gate SWCNT TFTs can be selectively converted into n-type by deposition of ethanolamine inks on the transistor active region via aerosol jet printing. Resulted n-type TFTs show excellent electrical properties with an on/off ratio of 10 6 , effective mobility up to 30 cm 2 V -1 s -1 , small hysteresis, and small subthreshold swing (90-140 mV dec -1 ), which are superior compared to the original p-type SWCNT devices. The n-type SWCNT TFTs also show good stability in air, and any deterioration of performance due to shelf storage can be fully recovered by a short low-temperature annealing. The easy polarity conversion process allows construction of CMOS circuitry. As an example, CMOS inverters were fabricated using printed p-type and n-type TFTs and exhibited a large noise margin (50 and 103% of 1/2 V dd = 1 V) and a voltage gain as high as 30 (at V dd = 1 V). Additionally, the CMOS inverters show full rail-to-rail output voltage swing and low power dissipation (0.1 μW at V dd = 1 V). The new method paves the way to construct fully functional complex CMOS circuitry by printed TFTs.

Erythropoietin during hypoglycaemia in type 1 diabetes: relation to basal renin-angiotensin system activity and cognitive function.

PubMed

Kristensen, Peter Lommer; Høi-Hansen, Thomas; Olsen, Niels Vidiendal; Pedersen-Bjergaard, Ulrik; Thorsteinsson, Birger

2009-07-01

Preservation of cognitive function during hypoglycaemic episodes is crucial for patients with insulin-treated diabetes to avoid severe hypoglycaemic events. Erythropoietin has neuroprotective potential. However, the role of erythropoietin during hypoglycaemia is unclear. The aim of the study was to explore plasma erythropoietin response to hypoglycaemia and the relationship to basal renin-angiotensin system (RAS) activity and cognitive function. We performed a single-blinded, controlled, cross-over study with induced hypoglycaemia or maintained glycaemic level. Nine patients with type 1 diabetes with high and nine with low activity in RAS were studied. Hypoglycaemia was induced using a standardized insulin-infusion. Overall, erythropoietin concentrations increased during hypoglycaemia. In the high RAS group erythropoietin rose 29% (p=0.032) whereas no significant response was observed in the low RAS group (7% increment; p=0.43). Independently, both hypoglycaemia and high RAS activity were associated with higher levels of erythropoietin (p=0.02 and 0.04, respectively). Low plasma erythropoietin at baseline was associated with poorer cognitive performance during hypoglycaemia. Hypoglycaemia triggers a rise in plasma erythropoietin in patients with type 1 diabetes. The response is influenced by basal RAS activity. Erythropoietin may carry a neuroprotective potential during hypoglycaemia.

Development of miniature moving magnet cryocooler SX040

NASA Astrophysics Data System (ADS)

Rühlich, I.; Mai, M.; Rosenhagen, C.; Schreiter, A.; Möhl, C.

2011-06-01

State of the art high performance cooled IR systems need to have more than just excellent E/O performance. Minimum size weight and power (SWaP) are the design goals to meet our forces' mission requirements. Key enabler for minimum SWaP of IR imagers is the operation temperature of the focal plane array (FPA) employed. State of the art MCT or InAsSb nBn technology has the potential to rise the FPA temperature from 77 K to 130-150 K (high operation temperature HOT) depending on the specific cut-off wavelength. Using a HOT FPA will significantly lower SWaP and keep those parameters finally dominated by the employed cryocooler. Therefore compact high performance cryocoolers are mandatory. For highest MTTF life AIM developed its Flexure Bearing Moving Magnet product family "SF". Such coolers achieve more than 20000 h MTTF with Stirling type expander and more than 5 years MTTF life with Pulse Tube coldfinger (like for Space applications). To keep the high lifetime potential but to significantly improve SWaP AIM is developing its "SX" type cooler family. The new SX040 cooler incorporates a highly efficient dual piston Moving Magnet driving mechanism resulting in very compact compressor of less than 100mm length. The cooler's high lifetime is also achieved by placing the coils outside the helium vessel as usual for moving magnet motors. The mating ¼" expander is extremely compact with less than 63 mm length. This allows a total dewar length from optical window to expander warm end of less than 100 mm even for large cold shields. The cooler is optimized for HOT detectors with operating temperatures exceeding 95 K. While this kind of cooler is the perfect match for many applications, handheld sights or targeting devices for the dismounted soldier are even more challenging with respect to SWaP. AIM therefore started to develop an even smaller cooler type with single piston and balancer. This paper gives an overview on the development of this new compact cryocooler. Technical details and performance data will be shown.

Effect of high fluence neutron irradiation on transport properties of thermoelectrics

DOE PAGES

Wang, H.; Leonard, K. J.

2017-07-25

Thermoelectric materials were subjected to high fluence neutron irradiation in order to understand the effect of radiation damage on transport properties. This paper is relevant to the NASA Radioisotope Thermoelectric Generator (RTG) program in which thermoelectric elements are exposed to radiation over a long period of time in space missions. Selected n-type and p-type bismuth telluride materials were irradiated at the High Flux Isotope Reactor with a neutron fluence of 1.3 × 10 18 n/cm 2 (E > 0.1 MeV). The increase in the Seebeck coefficient in the n-type material was partially off-set by an increase in electrical resistivity, makingmore » the power factor higher at lower temperatures. For the p-type materials, although the Seebeck coefficient was not affected by irradiation, electrical resistivity decreased slightly. The figure of merit, zT, showed a clear drop in the 300–400 K range for the p-type material and an increase for the n-type material. Considering that the p-type and n-type materials are connected in series in a module, the overall irradiation damages at the device level were limited. Finally, these results, at neutron fluences exceeding a typical space mission, are significant to ensure that the radiation damage to thermoelectrics does not affect the performance of RTGs.« less

Effect of high fluence neutron irradiation on transport properties of thermoelectrics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, H.; Leonard, K. J.

Thermoelectric materials were subjected to high fluence neutron irradiation in order to understand the effect of radiation damage on transport properties. This paper is relevant to the NASA Radioisotope Thermoelectric Generator (RTG) program in which thermoelectric elements are exposed to radiation over a long period of time in space missions. Selected n-type and p-type bismuth telluride materials were irradiated at the High Flux Isotope Reactor with a neutron fluence of 1.3 × 10 18 n/cm 2 (E > 0.1 MeV). The increase in the Seebeck coefficient in the n-type material was partially off-set by an increase in electrical resistivity, makingmore » the power factor higher at lower temperatures. For the p-type materials, although the Seebeck coefficient was not affected by irradiation, electrical resistivity decreased slightly. The figure of merit, zT, showed a clear drop in the 300–400 K range for the p-type material and an increase for the n-type material. Considering that the p-type and n-type materials are connected in series in a module, the overall irradiation damages at the device level were limited. Finally, these results, at neutron fluences exceeding a typical space mission, are significant to ensure that the radiation damage to thermoelectrics does not affect the performance of RTGs.« less

Completely transparent ohmic electrode on p-type AlGaN for UV LEDs with core-shell Cu@alloy nanosilk network (Conference Presentation)

NASA Astrophysics Data System (ADS)

Cai, Duanjun; Wang, Huachun; Huang, Youyang; Wu, Chenping; Chen, Xiaohong; Gao, Na; Wei, Tongbo T.; Wang, Junxi; Li, Shuping; Kang, Junyong

2016-09-01

Metal nanowire networks hold a great promise, which have been supposed the only alternative to ITO as transparent electrodes for their excellent performance in touch screen, LED and solar cell. It is well known that the difficulty in making transparent ohmic electrode to p-type high-Al-content AlGaN conducting layer has highly constrained the further development of UV LEDs. On the IWN-2014, we reported the ohmic contact to n, p-GaN with direct graphene 3D-coated Cu nanosilk network and the fabrication of complete blue LED. On the ICNS-2015, we reported the ohmic contact to n-type AlGaN conducting layer with Cu@alloy nanosilk network. Here, we further demonstrate the latest results that a novel technique is proposed for fabricating transparent ohmic electrode to high-Al-content AlGaN p-type conducting layer in UV LEDs using Cu@alloy core-shell nanosilk network. The superfine copper nanowires (16 nm) was synthesized for coating various metals such as Ni, Zn, V or Ti with different work functions. The transmittance showed a high transparency (> 90%) over a broad wavelength range from 200 to 3000 nm. By thermal annealing, ohmic contact was achieved on p-type Al0.5Ga0.5N layer with Cu@Ni nanosilk network, showing clearly linear I-V curve. By skipping the p-type GaN cladding layer, complete UV LED chip was fabricated and successfully lit with bright emission at 276 nm.

p-π Conjugated Polymers Based on Stable Triarylborane with n-Type Behavior in Optoelectronic Devices.

PubMed

Meng, Bin; Ren, Yi; Liu, Jun; Jäkle, Frieder; Wang, Lixiang

2018-02-19

p-π conjugation with embedded heteroatoms offers unique opportunities to tune the electronic structure of conjugated polymers. An approach is presented to form highly electron-deficient p-π conjugated polymers based on triarylboranes, demonstrate their n-type behavior, and explore device applications. By combining alternating [2,4,6-tris(trifluoromethyl)phenyl]di(thien-2-yl)borane (FBDT) and electron-deficient isoindigo (IID)/pyridine-flanked diketopyrrolopyrrole (DPPPy) units, we achieve low-lying lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) energy levels, high electron mobilities, and broad absorptions in the visible region. All-polymer solar cells with these polymers as electron acceptors exhibit encouraging photovoltaic performance with power conversion efficiencies of up to 2.83 %. These results unambiguously prove the n-type behavior and demonstrate the photovoltaic applications of p-π conjugated polymers based on triarylborane. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

InGaN-based thin film solar cells: Epitaxy, structural design, and photovoltaic properties

NASA Astrophysics Data System (ADS)

Sang, Liwen; Liao, Meiyong; Koide, Yasuo; Sumiya, Masatomo

2015-03-01

InxGa1-xN, with the tunable direct bandgaps from ultraviolet to near infrared region, offers a promising candidate for the high-efficiency next-generation thin-film photovoltaic applications. Although the adoption of thick InGaN film as the active region is desirable to obtain efficient light absorption and carrier collection compared to InGaN/GaN quantum wells structure, the understanding on the effect from structural design is still unclear due to the poor-quality InGaN films with thickness and difficulty of p-type doping. In this paper, we comprehensively investigate the effects from film epitaxy, doping, and device structural design on the performances of the InGaN-based solar cells. The high-quality InGaN thick film is obtained on AlN/sapphire template, and p-In0.08Ga0.92N is achieved with a high hole concentration of more than 1018 cm-3. The dependence of the photovoltaic performances on different structures, such as active regions and p-type regions is analyzed with respect to the carrier transport mechanism in the dark and under illumination. The strategy of improving the p-i interface by using a super-thin AlN interlayer is provided, which successfully enhances the performance of the solar cells.

Fabrication of p-type CuO thin films using chemical bath deposition technique and their solar cell applications with Si nanowires

NASA Astrophysics Data System (ADS)

Akgul, Funda Aksoy; Akgul, Guvenc

2017-02-01

Recently, CuO has attracted much interest owing to its suitable material properties, inexpensive fabrication cost and potential applications for optoelectronic devices. In this study, CuO thin films were deposited on glass substrates using chemical bath deposition technique and post-deposition annealing effect on the properties of the prepared samples were investigated. p-n heterojunction solar cells were then constructed by coating of p-type CuO films onto the vertically well-aligned n-type Si nanowires synthesized through MACE method. Photovoltaic performance of the fabricated devices were determined with current-voltage (I-V) measurements under AM 1.5 G illumination. The optimal short-circuit current density, open-circuit voltage, fill factor and power conversion efficiency were found to be 3.2 mA/cm-2, 337 mV, 37.9 and 0.45%, respectively. The observed performance clearly indicates that the investigated device structure could be a promising candidate for high-performance low-cost new-generation photovoltaic diodes.

Direct ultrasensitive electrical detection of prostate cancer biomarkers with CMOS-compatible n- and p-type silicon nanowire sensor arrays

NASA Astrophysics Data System (ADS)

Gao, Anran; Lu, Na; Dai, Pengfei; Fan, Chunhai; Wang, Yuelin; Li, Tie

2014-10-01

Sensitive and quantitative analysis of proteins is central to disease diagnosis, drug screening, and proteomic studies. Here, a label-free, real-time, simultaneous and ultrasensitive prostate-specific antigen (PSA) sensor was developed using CMOS-compatible silicon nanowire field effect transistors (SiNW FET). Highly responsive n- and p-type SiNW arrays were fabricated and integrated on a single chip with a complementary metal oxide semiconductor (CMOS) compatible anisotropic self-stop etching technique which eliminated the need for a hybrid method. The incorporated n- and p-type nanowires revealed complementary electrical response upon PSA binding, providing a unique means of internal control for sensing signal verification. The highly selective, simultaneous and multiplexed detection of PSA marker at attomolar concentrations, a level useful for clinical diagnosis of prostate cancer, was demonstrated. The detection ability was corroborated to be effective by comparing the detection results at different pH values. Furthermore, the real-time measurement was also carried out in a clinically relevant sample of blood serum, indicating the practicable development of rapid, robust, high-performance, and low-cost diagnostic systems.Sensitive and quantitative analysis of proteins is central to disease diagnosis, drug screening, and proteomic studies. Here, a label-free, real-time, simultaneous and ultrasensitive prostate-specific antigen (PSA) sensor was developed using CMOS-compatible silicon nanowire field effect transistors (SiNW FET). Highly responsive n- and p-type SiNW arrays were fabricated and integrated on a single chip with a complementary metal oxide semiconductor (CMOS) compatible anisotropic self-stop etching technique which eliminated the need for a hybrid method. The incorporated n- and p-type nanowires revealed complementary electrical response upon PSA binding, providing a unique means of internal control for sensing signal verification. The highly selective, simultaneous and multiplexed detection of PSA marker at attomolar concentrations, a level useful for clinical diagnosis of prostate cancer, was demonstrated. The detection ability was corroborated to be effective by comparing the detection results at different pH values. Furthermore, the real-time measurement was also carried out in a clinically relevant sample of blood serum, indicating the practicable development of rapid, robust, high-performance, and low-cost diagnostic systems. Electronic supplementary information (ESI) available: Electrical characterization of fabricated n- and p-type nanowires, and influence of Debye screening on PSA sensing. See DOI: 10.1039/c4nr03210a

Strong electrically tunable MoTe2/graphene van der Waals heterostructures for high-performance electronic and optoelectronic devices

NASA Astrophysics Data System (ADS)

Wang, Feng; Yin, Lei; Wang, Zhenxing; Xu, Kai; Wang, Fengmei; Shifa, Tofik Ahmed; Huang, Yun; Wen, Yao; Jiang, Chao; He, Jun

2016-11-01

MoTe2 is an emerging two-dimensional layered material showing ambipolar/p-type conductivity, which makes it an important supplement to n-type two-dimensional layered material like MoS2. However, the properties based on its van der Waals heterostructures have been rarely studied. Here, taking advantage of the strong Fermi level tunability of monolayer graphene (G) and the feature of van der Waals interfaces that is free from Fermi level pinning effect, we fabricate G/MoTe2/G van der Waals heterostructures and systematically study the electronic and optoelectronic properties. We demonstrate the G/MoTe2/G FETs with low Schottky barriers for both holes (55.09 meV) and electrons (122.37 meV). Moreover, the G/MoTe2/G phototransistors show high photoresponse performances with on/off ratio, responsivity, and detectivity of ˜105, 87 A/W, and 1012 Jones, respectively. Finally, we find the response time of the phototransistors is effectively tunable and a mechanism therein is proposed to explain our observation. This work provides an alternative choice of contact for high-performance devices based on p-type and ambipolar two-dimensional layered materials.

Synthesis of p-type GaN nanowires.

PubMed

Kim, Sung Wook; Park, Youn Ho; Kim, Ilsoo; Park, Tae-Eon; Kwon, Byoung Wook; Choi, Won Kook; Choi, Heon-Jin

2013-09-21

GaN has been utilized in optoelectronics for two decades. However, p-type doping still remains crucial for realization of high performance GaN optoelectronics. Though Mg has been used as a p-dopant, its efficiency is low due to the formation of Mg-H complexes and/or structural defects in the course of doping. As a potential alternative p-type dopant, Cu has been recognized as an acceptor impurity for GaN. Herein, we report the fabrication of Cu-doped GaN nanowires (Cu:GaN NWs) and their p-type characteristics. The NWs were grown vertically via a vapor-liquid-solid (VLS) mechanism using a Au/Ni catalyst. Electrical characterization using a nanowire-field effect transistor (NW-FET) showed that the NWs exhibited n-type characteristics. However, with further annealing, the NWs showed p-type characteristics. A homo-junction structure (consisting of annealed Cu:GaN NW/n-type GaN thin film) exhibited p-n junction characteristics. A hybrid organic light emitting diode (OLED) employing the annealed Cu:GaN NWs as a hole injection layer (HIL) also demonstrated current injected luminescence. These results suggest that Cu can be used as a p-type dopant for GaN NWs.

Layered Na‐Ion Cathodes with Outstanding Performance Resulting from the Synergetic Effect of Mixed P‐ and O‐Type Phases

PubMed Central

Keller, Marlou

2015-01-01

Herein, the synthesis of new quaternary layered Na‐based oxides of the type NaxMnyNizFe0.1Mg0.1O2 (0.67≤ x ≤ 1.0; 0.5≤ y ≤ 0.7; 0.1≤ z ≤ 0.3) is described. The synthesis can be tuned to obtain P2‐ and O3‐type as well as mixed P‐/O‐type phases as demonstrated by structural, morphological, and electrochemical properties characterization. Although all materials show good electrochemical performance, the simultaneous presence of the P‐ and O‐type phases is found to have a synergetic effect resulting in outstanding performance of the mixed phase material as a sodium‐ion cathode. The mixed P3/P2/O3‐type material, having an average elemental composition of Na0.76Mn0.5Ni0.3Fe0.1Mg0.1O2, overcomes the specific drawbacks associated with the P2‐ and O3‐type materials, allowing the outstanding electrochemical performance. In detail, the mixed phase material is able to deliver specific discharge capacities of up to 155 mAh g−1 (18 mA g−1) in the potential range of 2.0–4.3 V. In the narrower potential range of 2.5–4.3 V the material exhibits high average discharge potential (3.4 V versus Na/Na+), exceptional average coulombic efficiencies (>99.9%), and extraordinary capacity retention (90.2% after 601 cycles). The unexplored class of P‐/O‐type mixed phases introduces new perspectives for the development of layered positive electrode materials and powerful Na‐ion batteries. PMID:27134617

Nonlinear autoregressive neural networks with external inputs for forecasting of typhoon inundation level.

PubMed

Ouyang, Huei-Tau

2017-08-01

Accurate inundation level forecasting during typhoon invasion is crucial for organizing response actions such as the evacuation of people from areas that could potentially flood. This paper explores the ability of nonlinear autoregressive neural networks with exogenous inputs (NARX) to predict inundation levels induced by typhoons. Two types of NARX architecture were employed: series-parallel (NARX-S) and parallel (NARX-P). Based on cross-correlation analysis of rainfall and water-level data from historical typhoon records, 10 NARX models (five of each architecture type) were constructed. The forecasting ability of each model was assessed by considering coefficient of efficiency (CE), relative time shift error (RTS), and peak water-level error (PE). The results revealed that high CE performance could be achieved by employing more model input variables. Comparisons of the two types of model demonstrated that the NARX-S models outperformed the NARX-P models in terms of CE and RTS, whereas both performed exceptionally in terms of PE and without significant difference. The NARX-S and NARX-P models with the highest overall performance were identified and their predictions were compared with those of traditional ARX-based models. The NARX-S model outperformed the ARX-based models in all three indexes, whereas the NARX-P model exhibited comparable CE performance and superior RTS and PE performance.

A Spinel-integrated P2-type Layered Composite: High-rate Cathode for Sodium-ion Batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Jianming; Yan, Pengfei; Kan, Wang Hay

2016-01-14

Sodium-ion batteries (SIB) are being intensively investigated, owing to the natural abundance and low cost of Na resources. However, the SIBs still suffer from poor rate capability due to the large ionic radius of Na+ ion and the significant kinetic barrier to Na+-ion transport. Here, we present an Fd-3m spinel-integrated P2-type layered composite (P2 + Fd-3m) material as a high-rate cathode for SIBs. The P2 + Fd-3m composite material Na0.50Ni1/6Co1/6Mn2/3O2 shows significantly enhanced discharge capacity, energy density, and rate capability as compared to the pure P2-type counterpart. The composite delivers a high capacity of 85 mA h g-1 when dischargingmore » at a very high current density of 1500 mA g-1 (10C rate) between 2.0 and 4.5 V, validating it as a promising cathode candidate for high-power SIBs. The superior performance is ascribed to the improved kinetics in the presence of the integrated-spinel phase, which facilitates fast electron transport to coordinate with the timely Na+-ion insertion/extraction. The findings of this work also shed light on the importance of developing lattice doping, surface coating, and electrolyte additives to further improve the structural and interfacial stability of P2-type cathode materials and fully realize their practical applications in sodium-ion batteries.« less

In vivo dosimetry using a single diode for megavoltage photon beam radiotherapy: implementation and response characterization.

PubMed

Colussi, V C; Beddar, A S; Kinsella, T J; Sibata, C H

2001-01-01

The AAPM Task Group 40 reported that in vivo dosimetry can be used to identify major deviations in treatment delivery in radiation therapy. In this paper, we investigate the feasibility of using one single diode to perform in vivo dosimetry in the entire radiotherapeutic energy range regardless of its intrinsic buildup material. The only requirement on diode selection would be to choose a diode with the adequate build up to measure the highest beam energy. We have tested the new diodes from Sun Nuclear Corporation (called QED and ISORAD-p--both p-type) for low-, intermediate-, and high-energy range. We have clinically used both diode types to monitor entrance doses. In general, we found that the dose readings from the ISORAD (p-type) are closer of the dose expected than QED diodes in the clinical setting. In this paper we report on the response of these newly available ISORAD (p-type) diode detectors with respect to certain radiation field parameters such as source-to-surface distance, field size, wedge beam modifiers, as well as other parameters that affect detector characteristics (temperature and detector-beam orientation). We have characterized the response of the high-energy ISORAD (p-type) diode in the low- (1-4 MV), intermediate- (6-12 MV), and high-energy (15-25 MV) range. Our results showed that the total variation of the response of high-energy ISORAD (p-type) diodes to all the above parameters are within +/-5% in most encountered clinical patient treatment setups in the megavoltage photon beam radiotherapy. The usage of the high-energy buildup diode has the additional benefit of amplifying the response of the diode reading in case the wrong energy is used for patient treatment. In the light of these findings, we have since then switched to using only one single diode type, namely the "red" diode; manufacturer designation of the ISORAD (p-type) high-energy (15-25 MV) range diode, for all energies in our institution and satellites.

Carbon incorporation in InP grown by metalorganic chemical vapor deposition and application to InP/InGaAs heterojunction bipolar transistors

NASA Astrophysics Data System (ADS)

Stockman, S. A.; Fresina, M. T.; Hartmann, Q. J.; Hanson, A. W.; Gardner, N. F.; Baker, J. E.; Stillman, G. E.

1994-04-01

The incorporation of residual carbon has been studied for InP grown at low temperatures using TMIn and PH3 by low-pressure metalorganic chemical vapor deposition. n-type conduction is observed with electron concentrations as high as 1×1018 cm-3, and the electrical activation efficiency is 5%-15%. Carbon incorporation is found to be highly dependent on substrate temperature, suggesting that the rate-limiting step is desorption of CHy (0≤y≤3) from the surface during growth. Hydrogen is also incorporated in the layers during growth. The electron mobilities are lower for C-doped InP than for Si-doped InP. InP/InGaAs heterojunction bipolar transistors with C as the p-type base dopant and either Si or C as the n-type emitter dopant have been fabricated and compared. Devices with a carbon-doped base and emitter showed degraded performance, likely as a result of deep levels incorporated during growth of the emitter.

Unipolar Barrier Dual-Band Infrared Detectors

NASA Technical Reports Server (NTRS)

Ting, David Z. (Inventor); Soibel, Alexander (Inventor); Khoshakhlagh, Arezou (Inventor); Gunapala, Sarath (Inventor)

2017-01-01

Dual-band barrier infrared detectors having structures configured to reduce spectral crosstalk between spectral bands and/or enhance quantum efficiency, and methods of their manufacture are provided. In particular, dual-band device structures are provided for constructing high-performance barrier infrared detectors having reduced crosstalk and/or enhance quantum efficiency using novel multi-segmented absorber regions. The novel absorber regions may comprise both p-type and n-type absorber sections. Utilizing such multi-segmented absorbers it is possible to construct any suitable barrier infrared detector having reduced crosstalk, including npBPN, nBPN, pBPN, npBN, npBP, pBN and nBP structures. The pBPN and pBN detector structures have high quantum efficiency and suppresses dark current, but has a smaller etch depth than conventional detectors and does not require a thick bottom contact layer.

High Beginning-of-Life Efficiency p/n InP Solar Cells

NASA Technical Reports Server (NTRS)

Hoffman, Richard W., Jr.; Fatemi, Navid S.; Weizer, Victor G.; Jenkins, Phillip P.; Ringel, Steven A.; Scheiman, David A.; Wilt, David M.; Brinker, David J.

2004-01-01

We have achieved a new record efficiency of 17.6%, (AM0) for a p/n InP homo-epitaxy solar cell. In addition, we have eliminated a previously observed photo-degradation of cell performance, which was due to losses in J(sub sc). Cells soaked in AM0 spectrum at one-sun intensity for an hour showed no significant change in cell performance. We have discovered carrier passivation effects when using Zn as the p-type dopant in the OMVPE growth of InP and have found a method to avoid the unexpected effects which result from typical operation of OMVPE cell growth.

Sustained hole inversion layer in a wide-bandgap metal-oxide semiconductor with enhanced tunnel current

NASA Astrophysics Data System (ADS)

Shoute, Gem; Afshar, Amir; Muneshwar, Triratna; Cadien, Kenneth; Barlage, Douglas

2016-02-01

Wide-bandgap, metal-oxide thin-film transistors have been limited to low-power, n-type electronic applications because of the unipolar nature of these devices. Variations from the n-type field-effect transistor architecture have not been widely investigated as a result of the lack of available p-type wide-bandgap inorganic semiconductors. Here, we present a wide-bandgap metal-oxide n-type semiconductor that is able to sustain a strong p-type inversion layer using a high-dielectric-constant barrier dielectric when sourced with a heterogeneous p-type material. A demonstration of the utility of the inversion layer was also investigated and utilized as the controlling element in a unique tunnelling junction transistor. The resulting electrical performance of this prototype device exhibited among the highest reported current, power and transconductance densities. Further utilization of the p-type inversion layer is critical to unlocking the previously unexplored capability of metal-oxide thin-film transistors, such applications with next-generation display switches, sensors, radio frequency circuits and power converters.

High potential thermoelectric figure of merit in ternary La 3Cu 3X 4 (X = P, As, Sb and Bi) compounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pandey, Tribhuwan; Parker, David S.

Here, we investigate the thermoelectric properties of the relatively unexplored rare-earth ternary compounds La 3Cu 3X 4 (X= Bi, Sb, As, and P) using first principles electronic structure and Boltzmann transport calculations. These compounds, of which the La 3Cu 3Sb 4 and La 3Cu 3Bi 4 compounds have previously been synthesized, are all predicted to semiconductors and present a wide range of band gaps varying from 0.23 eV (for the Bi compound) to 0.87 eV (for the P compound). We further find a mixture of light and heavy bands, which results in a high thermoelectric power factor. In addition wemore » find that at high temperatures of 1000 K these compounds exhibit lattice thermal conductivity less than 1 W/m-K. The combination of low thermal conductivity and good transport properties results in a predicted ZT as high as ~1.5 for both La 3Cu 3P 4 and La 3Cu 3As 4, under high p-type doping. This predicted high performance makes these compounds promising candidates for high performance thermoelectric performance and thus merits further experimental investigation.« less

High potential thermoelectric figure of merit in ternary La 3Cu 3X 4 (X = P, As, Sb and Bi) compounds

DOE PAGES

Pandey, Tribhuwan; Parker, David S.

2017-10-27

Here, we investigate the thermoelectric properties of the relatively unexplored rare-earth ternary compounds La 3Cu 3X 4 (X= Bi, Sb, As, and P) using first principles electronic structure and Boltzmann transport calculations. These compounds, of which the La 3Cu 3Sb 4 and La 3Cu 3Bi 4 compounds have previously been synthesized, are all predicted to semiconductors and present a wide range of band gaps varying from 0.23 eV (for the Bi compound) to 0.87 eV (for the P compound). We further find a mixture of light and heavy bands, which results in a high thermoelectric power factor. In addition wemore » find that at high temperatures of 1000 K these compounds exhibit lattice thermal conductivity less than 1 W/m-K. The combination of low thermal conductivity and good transport properties results in a predicted ZT as high as ~1.5 for both La 3Cu 3P 4 and La 3Cu 3As 4, under high p-type doping. This predicted high performance makes these compounds promising candidates for high performance thermoelectric performance and thus merits further experimental investigation.« less

Critical determinants of combined sprint and endurance performance: an integrative analysis from muscle fiber to the human body.

PubMed

van der Zwaard, Stephan; van der Laarse, Willem J; Weide, Guido; Bloemers, Frank W; Hofmijster, Mathijs J; Levels, Koen; Noordhof, Dionne A; de Koning, Jos J; de Ruiter, Cornelis J; Jaspers, Richard T

2018-04-01

Optimizing physical performance is a major goal in current physiology. However, basic understanding of combining high sprint and endurance performance is currently lacking. This study identifies critical determinants of combined sprint and endurance performance using multiple regression analyses of physiologic determinants at different biologic levels. Cyclists, including 6 international sprint, 8 team pursuit, and 14 road cyclists, completed a Wingate test and 15-km time trial to obtain sprint and endurance performance results, respectively. Performance was normalized to lean body mass 2/3 to eliminate the influence of body size. Performance determinants were obtained from whole-body oxygen consumption, blood sampling, knee-extensor maximal force, muscle oxygenation, whole-muscle morphology, and muscle fiber histochemistry of musculus vastus lateralis. Normalized sprint performance was explained by percentage of fast-type fibers and muscle volume ( R 2 = 0.65; P < 0.001) and normalized endurance performance by performance oxygen consumption ( V̇o 2 ), mean corpuscular hemoglobin concentration, and muscle oxygenation ( R 2 = 0.92; P < 0.001). Combined sprint and endurance performance was explained by gross efficiency, performance V̇o 2 , and likely by muscle volume and fascicle length ( P = 0.056; P = 0.059). High performance V̇o 2 related to a high oxidative capacity, high capillarization × myoglobin, and small physiologic cross-sectional area ( R 2 = 0.67; P < 0.001). Results suggest that fascicle length and capillarization are important targets for training to optimize sprint and endurance performance simultaneously.-Van der Zwaard, S., van der Laarse, W. J., Weide, G., Bloemers, F. W., Hofmijster, M. J., Levels, K., Noordhof, D. A., de Koning, J. J., de Ruiter, C. J., Jaspers, R. T. Critical determinants of combined sprint and endurance performance: an integrative analysis from muscle fiber to the human body.

Direct ultrasensitive electrical detection of prostate cancer biomarkers with CMOS-compatible n- and p-type silicon nanowire sensor arrays.

PubMed

Gao, Anran; Lu, Na; Dai, Pengfei; Fan, Chunhai; Wang, Yuelin; Li, Tie

2014-11-07

Sensitive and quantitative analysis of proteins is central to disease diagnosis, drug screening, and proteomic studies. Here, a label-free, real-time, simultaneous and ultrasensitive prostate-specific antigen (PSA) sensor was developed using CMOS-compatible silicon nanowire field effect transistors (SiNW FET). Highly responsive n- and p-type SiNW arrays were fabricated and integrated on a single chip with a complementary metal oxide semiconductor (CMOS) compatible anisotropic self-stop etching technique which eliminated the need for a hybrid method. The incorporated n- and p-type nanowires revealed complementary electrical response upon PSA binding, providing a unique means of internal control for sensing signal verification. The highly selective, simultaneous and multiplexed detection of PSA marker at attomolar concentrations, a level useful for clinical diagnosis of prostate cancer, was demonstrated. The detection ability was corroborated to be effective by comparing the detection results at different pH values. Furthermore, the real-time measurement was also carried out in a clinically relevant sample of blood serum, indicating the practicable development of rapid, robust, high-performance, and low-cost diagnostic systems.

Effect of Game Design, Goal Type, and Player Numbers on the Physiological and Physical Demands of Hurling-Specific Small-Sided Games.

PubMed

Malone, Shane; Collins, Kieran D

2017-06-01

The current study examined the effect that game design modification, goal type, and player numbers on the running performance and physiological demands of small-sided hurling games (SSG). Forty-eight hurling players (age, 25.5 ± 3.2 years; height, 178.9 ± 3.2 cm; body mass, 78.5 ± 4.5 kg) performed 4 types of SSG (possession [P], normal play [NP], regular goals [RG] and small goals [SG]) in 4-a-side, 5-a-side, and 6-a-side formats. Heart rate (Polar Electro Oy) and global positioning system technology (VX Sport, 4-Hz, Lower Hutt) were used to analyze the physical and physiological differences between SSG. Total distance (m), high-speed running distance (m) (≥17 km·h), very-high speed running distance (≥22 km·h) (m), peak and mean velocity (km·h) were analyzed as an indicator of the physical demands of play. The 4-a-side SSG independent of game design and goal type resulted in a significantly higher relative exercise intensity compared with 5-a-side (mean change: 6 ± 2%; p = 0.001; d = 1.9 ± 0.2; large) and 6-a-side SSG independent of game design or goal type (mean change: 12 ± 2%; p = 0.001; d = 2.9 ± 0.8; very large). The 4-a-side SG (619 ± 106-m [419-735-m]) resulted in the highest distance when compared with all PP (mean change: 141 ± 9 m; p = 0.05; d = 1.9 ± 0.3; moderate) and RG (mean change: 119 ± 39 m; p = 0.004; d = 2.1 ± 0.8; large). Similar trends were observed for 5-a-side and 6-a-side games with SG resulting in increased total running performance. In conclusion, the current observations reveal that 4-a-side NP, SG, and RG have the highest physiological demands with 4-a-side SG having increased running performance in contrast to other game design and goal-type games. Furthermore, independent of game design and goal type, 4-a-side SSG show increased relative intensity compared with 5-a-side and 6-a-side SSG.

Only minor changes in thrombin generation of children and adolescents with type 1 diabetes mellitus - A case-control study.

PubMed

Cimenti, Christina; Schlagenhauf, Axel; Leschnik, Bettina; Fröhlich-Reiterer, Elke; Jasser-Nitsche, Hildegard; Haidl, Harald; Suppan, Elisabeth; Weinhandl, Gudrun; Leberl, Maximilian; Borkenstein, Martin; Muntean, Wolfgang E

2016-12-01

Micro- and macrovascular diseases are frequent complications in patients with diabetes. Hypercoagulability may contribute to microvascular alterations. In this study, we investigated whether type 1 diabetes in children is associated with a hypercoagulable state by performing a global function test of coagulation - the thrombin generation assay. 75 patients with type 1 diabetes aged between 2 and 19years were compared to an age-matched healthy control group. Diabetes patients were divided into high-dose and low-dose insulin cohorts with a cut-off at 0.8Ukg -1 d -1 . Measurements were performed with platelet poor plasma using Calibrated Automated Thrombography and 1 pM or 5 pM tissue factor. Additionally, we quantified prothrombin fragments F1+2, thrombin-antithrombin complex, prothrombin, tissue factor pathway inhibitor, and antithrombin. Patients with type 1 diabetes exhibited a significantly shorter of lag time as well as decreased thrombin peak and endogenous thrombin potential compared to control subjects with 5 pM but not with 1 pM tissue factor. In high-dose insulin patients peak thrombin generation was higher and time to peak shorter than in low-dose patients. Thrombin-antithrombin complex was decreased in patients with type 1 diabetes, whereas prothrombin fragments F1+2 was comparable in both groups. Thrombin generation parameters did not correlate with parameters of metabolic control and the duration of diabetes. Taken together, we found only minor changes of thrombin generation in children and adolescents with type 1 diabetes which - in contrast to type 2 diabetes - do not argue for a hypercoagulable state. Copyright © 2016 Elsevier Ltd. All rights reserved.

Novel p-Type Conductive Semiconductor Nanocrystalline Film as the Back Electrode for High-Performance Thin Film Solar Cells.

PubMed

Zhang, Ming-Jian; Lin, Qinxian; Yang, Xiaoyang; Mei, Zongwei; Liang, Jun; Lin, Yuan; Pan, Feng

2016-02-10

Thin film solar cells, due to the low cost, high efficiency, long-term stability, and consumer applications, have been widely applied for harvesting green energy. All of these thin film solar cells generally adopt various metal thin films as the back electrode, like Mo, Au, Ni, Ag, Al, graphite, and so forth. When they contact with p-type layer, it always produces a Schottky contact with a high contact potential barrier, which greatly affects the cell performance. In this work, we report for the first time to find an appropriate p-type conductive semiconductor film, digenite Cu9S5 nanocrystalline film, as the back electrode for CdTe solar cells as the model device. Its low sheet resistance (16.6 Ω/sq) could compare to that of the commercial TCO films (6-30 Ω/sq), like FTO, ITO, and AZO. Different from the traditonal metal back electrode, it produces a successive gradient-doping region by the controllable Cu diffusion, which greatly reduces the contact potential barrier. Remarkably, it achieved a comparable power conversion efficiency (PCE, 11.3%) with the traditional metal back electrode (Cu/Au thin films, 11.4%) in CdTe cells and a higher PCE (13.8%) with the help of the Au assistant film. We believe it could also act as the back electrode for other thin film solar cells (α-Si, CuInS2, CIGSe, CZTS, etc.), for their performance improvement.

The responses of subjective feeling, task performance ability, cortisol and HRV for the various types of floor impact sound: a pilot study.

PubMed

Yun, Seok Hyeon; Park, Sang Jin; Sim, Chang Sun; Sung, Joo Hyun; Kim, Ahra; Lee, Jang Myeong; Lee, Sang Hyun; Lee, Jiho

2017-01-01

Recently, noise coming from the neighborhood via floor wall has become a great social problem. The noise between the floors can be a cause of physical and psychological problems, and the different types of floor impact sound (FIS) may have the different effects on the human's body and mind. The purpose of this study is to assess the responses of subjective feeling, task performance ability, cortisol and HRV for the various types of floor impact. Ten men and 5 women were enrolled in our study, and the English listening test was performed under the twelve different types of FIS, which were made by the combinations of bang machine (B), tapping machine (T), impact ball (I) and sound-proof mattress (M). The 15 subjects were exposed to each FIS for about 3 min, and the subjective annoyance, performance ability (English listening test), cortisol level of urine/saliva and heart rate variability (HRV) were examined. The sound pressure level (SPL) and frequency of FIS were analyzed. Repeated-measures ANOVA, paired t-test, Wilcoxon signed rank test were performed for data analysis. The SPL of tapping machine (T) was reduced with the soundproof mattress (M) by 3.9-7.3 dBA. Impact ball (I) was higher than other FIS in low frequency (31.5-125 Hz) by 10 dBA, and tapping machine (T) was higher than other FIS in high frequency (2-4 k Hz) by 10 dBA. The subjective annoyance is highest in the combination of bang machine and tapping machine (BT), and next in the tapping machine (T). The English listening score was also lowest in the BT, and next in T. The difference of salivary cortisol levels between various types of FIS was significant ( p  = 0.003). The change of HRV parameters by the change of FIS types was significant in some parameters, which were total power (TP) ( p  = 0.004), low frequency (LF) ( p  = 0.002) and high frequency (HF) ( p  = 0.011). These results suggest that the human's subjective and objective responses were different according to FIS types and those combinations.

InAlAs photovoltaic cell design for high device efficiency

DOE PAGES

Smith, Brittany L.; Bittner, Zachary S.; Hellstroem, Staffan D.; ...

2017-04-17

This study presents a new design for a single-junction InAlAs solar cell, which reduces parasitic absorption losses from the low band-gap contact layer while maintaining a functional window layer by integrating a selective etch stop. The etch stop is then removed prior to depositing an anti-reflective coating. The final cell had a 17.9% efficiency under 1-sun AM1.5 with an anti-reflective coating. Minority carrier diffusion lengths were extracted from external quantum efficiency data using physics-based device simulation software yielding 170 nm in the n-type emitter and 4.6 um in the p-type base, which is more than four times the diffusion lengthmore » previously reported for a p-type InAlAs base. In conclusion, this report represents significant progress towards a high-performance InAlAs top cell for a triple-junction design lattice-matched to InP.« less

Suppressing spontaneous polarization of p-GaN by graphene oxide passivation: Augmented light output of GaN UV-LED

PubMed Central

Jeong, Hyun; Jeong, Seung Yol; Park, Doo Jae; Jeong, Hyeon Jun; Jeong, Sooyeon; Han, Joong Tark; Jeong, Hee Jin; Yang, Sunhye; Kim, Ho Young; Baeg, Kang-Jun; Park, Sae June; Ahn, Yeong Hwan; Suh, Eun-Kyung; Lee, Geon-Woong; Lee, Young Hee; Jeong, Mun Seok

2015-01-01

GaN-based ultraviolet (UV) LEDs are widely used in numerous applications, including white light pump sources and high-density optical data storage. However, one notorious issue is low hole injection rate in p-type transport layer due to poorly activated holes and spontaneous polarization, giving rise to insufficient light emission efficiency. Therefore, improving hole injection rate is a key step towards high performance UV-LEDs. Here, we report a new method of suppressing spontaneous polarization in p-type region to augment light output of UV-LEDs. This was achieved by simply passivating graphene oxide (GO) on top of the fully fabricated LED. The dipole layer formed by the passivated GO enhanced hole injection rate by suppressing spontaneous polarization in p-type region. The homogeneity of electroluminescence intensity in active layers was improved due to band filling effect. As a consequence, the light output was enhanced by 60% in linear current region. Our simple approach of suppressing spontaneous polarization of p-GaN using GO passivation disrupts the current state of the art technology and will be useful for high-efficiency UV-LED technology. PMID:25586148

Suppressing spontaneous polarization of p-GaN by graphene oxide passivation: augmented light output of GaN UV-LED.

PubMed

Jeong, Hyun; Jeong, Seung Yol; Park, Doo Jae; Jeong, Hyeon Jun; Jeong, Sooyeon; Han, Joong Tark; Jeong, Hee Jin; Yang, Sunhye; Kim, Ho Young; Baeg, Kang-Jun; Park, Sae June; Ahn, Yeong Hwan; Suh, Eun-Kyung; Lee, Geon-Woong; Lee, Young Hee; Jeong, Mun Seok

2015-01-14

GaN-based ultraviolet (UV) LEDs are widely used in numerous applications, including white light pump sources and high-density optical data storage. However, one notorious issue is low hole injection rate in p-type transport layer due to poorly activated holes and spontaneous polarization, giving rise to insufficient light emission efficiency. Therefore, improving hole injection rate is a key step towards high performance UV-LEDs. Here, we report a new method of suppressing spontaneous polarization in p-type region to augment light output of UV-LEDs. This was achieved by simply passivating graphene oxide (GO) on top of the fully fabricated LED. The dipole layer formed by the passivated GO enhanced hole injection rate by suppressing spontaneous polarization in p-type region. The homogeneity of electroluminescence intensity in active layers was improved due to band filling effect. As a consequence, the light output was enhanced by 60% in linear current region. Our simple approach of suppressing spontaneous polarization of p-GaN using GO passivation disrupts the current state of the art technology and will be useful for high-efficiency UV-LED technology.

Biological relevance of human papillomaviruses in vulvar cancer.

PubMed

Halec, Gordana; Alemany, Laia; Quiros, Beatriz; Clavero, Omar; Höfler, Daniela; Alejo, Maria; Quint, Wim; Pawlita, Michael; Bosch, Francesc X; de Sanjose, Silvia

2017-04-01

The carcinogenic role of high-risk human papillomavirus (HR-HPV) types in the increasing subset of vulvar intraepithelial neoplasia and vulvar cancer in young women has been established. However, the actual number of vulvar cancer cases attributed to HPV is still imprecisely defined. In an attempt to provide a more precise definition of HPV-driven vulvar cancer, we performed HPV-type-specific E6*I mRNA analyses available for 20 HR-/possible HR (pHR)-HPV types, on tissue samples from 447 cases of vulvar cancer. HPV DNA genotyping was performed using SPF10-LiPA 25 assay due to its high sensitivity in formalin-fixed paraffin-embedded tissues. Data on p16 INK4a expression was available for comparative analysis via kappa statistics. The use of highly sensitive assays covering the detection of HPV mRNA in a broad spectrum of mucosal HPV types resulted in the detection of viral transcripts in 87% of HPV DNA+ vulvar cancers. Overall concordance between HPV mRNA+ and p16 INK4a upregulation (strong, diffuse immunostaining in >25% of tumor cells) was 92% (K=0.625, 95% confidence interval (CI)=0.531-0.719). Among these cases, 83% were concordant pairs of HPV mRNA+ and p16 INK4a + and 9% were concordant pairs of HPV mRNA- and p16 INK4a -. Our data confirm the biological role of HR-/pHR-HPV types in the great majority of HPV DNA+ vulvar cancers, resulting in an HPV-attributable fraction of at least 21% worldwide. Most HPV DNA+ vulvar cancers were associated with HPV16 (85%), but a causative role for other, less frequently occurring mucosal HPV types (HPV26, 66, 67, 68, 70 and 73) was also confirmed at the mRNA level for the first time. These findings should be taken into consideration for future screening options as HPV-associated vulvar preneoplastic lesions have increased in incidence in younger women and require different treatment than vulvar lesions that develop from rare autoimmune-related mechanisms in older women.

Thermoelectric Performance and Defect Chemistry in n-Type Zintl KGaSb 4

DOE PAGES

Ortiz, Brenden R.; Gorai, Prashun; Stevanovic, Vladan; ...

2017-05-08

The rise of high-throughput calculations has accelerated the discovery of promising classes of thermoelectric materials. In prior work, we identified the n-type Zintl pnictides as one such material class. To date, however, a lack of detailed defect calculations and chemical intuition has led the community to investigate p-type Zintls almost exclusively. Here, we investigate the synthesis, thermoelectric properties, and defect structure of the complex Zintl KGaSb 4. We find that KGaSb 4 is successfully doped n-type with Ba and has the potential for p-type doping with Zn. Our calculations reveal the fundamental defect structure in KGaSb 4 that enables n-typemore » and p-type doping. We find that Ba doped KGaSb4 exhibits high electronic mobility (~50 cm 2V -1s -1) and near minimum lattice thermal conductivity (<0.5 Wm -1K -1) at 400 °C. Samples doped with 1.5% Ba achieve zT > 0.9 at 400 °C, promising for a previously unstudied material. Here, we also briefly investigate the series of alloys between KGaSb 4 and KAlSb 4, finding that a full solid solution exists. Altogether our work reinforces motivation for the exploration of n-type Zintl materials, especially in tandem with high-throughput defect calculations to inform selection of effective dopants and systems amenable to n-type transport.« less

Thermoelectric Performance and Defect Chemistry in n-Type Zintl KGaSb 4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ortiz, Brenden R.; Gorai, Prashun; Stevanovic, Vladan

The rise of high-throughput calculations has accelerated the discovery of promising classes of thermoelectric materials. In prior work, we identified the n-type Zintl pnictides as one such material class. To date, however, a lack of detailed defect calculations and chemical intuition has led the community to investigate p-type Zintls almost exclusively. Here, we investigate the synthesis, thermoelectric properties, and defect structure of the complex Zintl KGaSb 4. We find that KGaSb 4 is successfully doped n-type with Ba and has the potential for p-type doping with Zn. Our calculations reveal the fundamental defect structure in KGaSb 4 that enables n-typemore » and p-type doping. We find that Ba doped KGaSb4 exhibits high electronic mobility (~50 cm 2V -1s -1) and near minimum lattice thermal conductivity (<0.5 Wm -1K -1) at 400 °C. Samples doped with 1.5% Ba achieve zT > 0.9 at 400 °C, promising for a previously unstudied material. Here, we also briefly investigate the series of alloys between KGaSb 4 and KAlSb 4, finding that a full solid solution exists. Altogether our work reinforces motivation for the exploration of n-type Zintl materials, especially in tandem with high-throughput defect calculations to inform selection of effective dopants and systems amenable to n-type transport.« less

Novel organic semiconductors and dielectric materials for high performance and low-voltage organic thin-film transistors

NASA Astrophysics Data System (ADS)

Yoon, Myung-Han

Two novel classes of organic semiconductors based on perfluoroarene/arene-modified oligothiophenes and perfluoroacyl/acyl-derivatized quaterthiophens are developed. The frontier molecular orbital energies of these compounds are studied by optical spectroscopy and electrochemistry while solid-state/film properties are investigated by thermal analysis, x-ray diffraction, and scanning electron microscopy. Organic thin film transistors (OTFTs) performance parameters are discussed in terms of the interplay between semiconductor molecular energetics and film morphologies/microstructures. For perfluoroarene-thiophene oligomer systems, majority charge carrier type and mobility exhibit a strong correlation with the regiochemistry of perfluoroarene incorporation. In quaterthiophene-based semiconductors, carbonyl-functionalization allows tuning of the majority carrier type from p-type to ambipolar and to n-type. In situ conversion of a p-type semiconducting film to n-type film is also demonstrated. Very thin self-assembled or spin-on organic dielectric films have been integrated into OTFTs to achieve 1 - 2 V operating voltages. These new dielectrics are deposited either by layer-by-layer solution phase deposition of molecular precursors or by spin-coating a mixture of polymer and crosslinker, resulting in smooth and virtually pinhole-free thin films having exceptionally large capacitances (300--700 nF/cm2) and low leakage currents (10 -9 - 10-7 A/cm2). These organic dielectrics are compatible with various vapor- or solution-deposited p- and n-channel organic semiconductors. Furthermore, it is demonstrated that spin-on crosslinked-polymer-blend dielectrics can be employed for large-area/patterned electronics, and complementary inverters. A general approach for probing semiconductor-dielectric interface effects on OTFT performance parameters using bilayer gate dielectrics is presented. Organic semiconductors having p-, n-type, or ambipolar majority charge carriers are grown on six different bilayer dielectrics consisting of various spin-coated polymers/HMDS on 300 nm SiO2/p+-Si, followed by transistor fabrication. In case of air-sensitive n-type semiconductors, dielectric surface modifications induce large variations in the corresponding OTFT performance parameters while film morphologies and microstructures remain unchanged. In contrast, the device performance of air-stable n-type and p-type semiconductors is not significantly affected by dielectric surface modifications. The origin of the mobility sensitivity to the various surface chemistries in the case of air sensitive n-type semiconductors is found to be due to electron trapping by silanol and carbonyl functionalities at the semiconductor-dielectric interface.

Balancing Hole and Electron Conduction in Ambipolar Split-Gate Thin-Film Transistors.

PubMed

Yoo, Hocheon; Ghittorelli, Matteo; Lee, Dong-Kyu; Smits, Edsger C P; Gelinck, Gerwin H; Ahn, Hyungju; Lee, Han-Koo; Torricelli, Fabrizio; Kim, Jae-Joon

2017-07-10

Complementary organic electronics is a key enabling technology for the development of new applications including smart ubiquitous sensors, wearable electronics, and healthcare devices. High-performance, high-functionality and reliable complementary circuits require n- and p-type thin-film transistors with balanced characteristics. Recent advancements in ambipolar organic transistors in terms of semiconductor and device engineering demonstrate the great potential of this route but, unfortunately, the actual development of ambipolar organic complementary electronics is currently hampered by the uneven electron (n-type) and hole (p-type) conduction in ambipolar organic transistors. Here we show ambipolar organic thin-film transistors with balanced n-type and p-type operation. By manipulating air exposure and vacuum annealing conditions, we show that well-balanced electron and hole transport properties can be easily obtained. The method is used to control hole and electron conductions in split-gate transistors based on a solution-processed donor-acceptor semiconducting polymer. Complementary logic inverters with balanced charging and discharging characteristics are demonstrated. These findings may open up new opportunities for the rational design of complementary electronics based on ambipolar organic transistors.

Time-to-positivity, type of culture media and oxidase test performed on positive blood culture vials to predict Pseudomonas aeruginosa in patients with Gram-negative bacilli bacteraemia.

PubMed

Cobos-Triguero, N; Zboromyrska, Y; Morata, L; Alejo, I; De La Calle, C; Vergara, A; Cardozo, C; Arcas, M P; Soriano, A; Marco, F; Mensa, J; Almela, M; Martínez, J A

2017-02-01

The aim of this study was to determine the usefulness of oxidase test and time-to-positivity (TTP) in aerobic and anaerobic blood culture vials to detect the presence of Pseudomonas aeruginosa in patients with Gram-negative bacilli (GNB) bacteraemia. TTP was recorded for each aerobic and anaerobic blood culture vial of monomicrobial bacteraemia due to GNB. Oxidase test was performed in a pellet of the centrifuged content of the positive blood culture. An algorithm was developed in order to perform the oxidase test efficiently taking into account TTP and type of vial. A total of 341 episodes of GNB bacteraemia were analysed. Sensitivity, specificity, positive predictive value and negative predictive value of the oxidase test performed on positive vials with GNB to predict P. aeruginosa were 95%, 99%, 91%, and 99%, respectively. When growth was first or exclusively detected in anaerobic vials, P. aeruginosa was never identified hence the performance of the oxidase test could be avoided. When growth was only or first detected in aerobic vials, a TTP≥8h predicted P. aeruginosa in 37% or cases (63 of 169), therefore oxidase test is highly recommended. Oxidase test performed onto positive blood culture vials previously selected by TTP and type of vials is an easy and inexpensive way to predict P. aeruginosa. In most cases, this can lead to optimization of treatment in less than 24 hours.

All oxide semiconductor-based bidirectional vertical p-n-p selectors for 3D stackable crossbar-array electronics

PubMed Central

Bae, Yoon Cheol; Lee, Ah Rahm; Baek, Gwang Ho; Chung, Je Bock; Kim, Tae Yoon; Park, Jea Gun; Hong, Jin Pyo

2015-01-01

Three-dimensional (3D) stackable memory devices including nano-scaled crossbar array are central for the realization of high-density non-volatile memory electronics. However, an essential sneak path issue affecting device performance in crossbar array remains a bottleneck and a grand challenge. Therefore, a suitable bidirectional selector as a two-way switch is required to facilitate a major breakthrough in the 3D crossbar array memory devices. Here, we show the excellent selectivity of all oxide p-/n-type semiconductor-based p-n-p open-based bipolar junction transistors as selectors in crossbar memory array. We report that bidirectional nonlinear characteristics of oxide p-n-p junctions can be highly enhanced by manipulating p-/n-type oxide semiconductor characteristics. We also propose an associated Zener tunneling mechanism that explains the unique features of our p-n-p selector. Our experimental findings are further extended to confirm the profound functionality of oxide p-n-p selectors integrated with several bipolar resistive switching memory elements working as storage nodes. PMID:26289565

TP53 Mutation Status of Tubo-ovarian and Peritoneal High-grade Serous Carcinoma with a Wild-type p53 Immunostaining Pattern.

PubMed

Na, Kiyong; Sung, Ji-Youn; Kim, Hyun-Soo

2017-12-01

Diffuse and strong nuclear p53 immunoreactivity and a complete lack of p53 expression are regarded as indicative of missense and nonsense mutations, respectively, of the TP53 gene. Tubo-ovarian and peritoneal high-grade serous carcinoma (HGSC) is characterized by aberrant p53 expression induced by a TP53 mutation. However, our experience with some HGSC cases with a wild-type p53 immunostaining pattern led us to comprehensively review previous cases and investigate the TP53 mutational status of the exceptional cases. We analyzed the immunophenotype of 153 cases of HGSC and performed TP53 gene sequencing analysis in those with a wild-type p53 immunostaining pattern. Immunostaining revealed that 109 (71.3%) cases displayed diffuse and strong p53 expression (missense mutation pattern), while 39 (25.5%) had no p53 expression (nonsense mutation pattern). The remaining five cases of HGSC showed a wild-type p53 immunostaining pattern. Direct sequencing analysis revealed that three of these cases harbored nonsense TP53 mutations and two had novel splice site deletions. TP53 mutation is almost invariably present in HGSC, and p53 immunostaining can be used as a surrogate marker of TP53 mutation. In cases with a wild-type p53 immunostaining pattern, direct sequencing for TP53 mutational status can be helpful to confirm the presence of a TP53 mutation. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Highly efficient single-junction GaAs thin-film solar cell on flexible substrate.

PubMed

Moon, Sunghyun; Kim, Kangho; Kim, Youngjo; Heo, Junseok; Lee, Jaejin

2016-07-20

There has been much interest in developing a thin-film solar cell because it is lightweight and flexible. The GaAs thin-film solar cell is a top contender in the thin-film solar cell market in that it has a high power conversion efficiency (PCE) compared to that of other thin-film solar cells. There are two common structures for the GaAs solar cell: n (emitter)-on-p (base) and p-on-n. The former performs better due to its high collection efficiency because the electron diffusion length of the p-type base region is much longer than the hole diffusion length of the n-type base region. However, it has been limited to fabricate highly efficient n-on-p single-junction GaAs thin film solar cell on a flexible substrate due to technical obstacles. We investigated a simple and fast epitaxial lift-off (ELO) method that uses a stress originating from a Cr/Au bilayer on a 125-μm-thick flexible substrate. A metal combination of AuBe/Pt/Au is employed as a new p-type ohmic contact with which an n-on-p single-junction GaAs thin-film solar cell on flexible substrate was successfully fabricated. The PCE of the fabricated single-junction GaAs thin-film solar cells reached 22.08% under air mass 1.5 global illumination.

Gliomatosis cerebri: clinicopathologic study of 33 cases and comparison of mass forming and diffuse types.

PubMed

Park, S; Suh, Y-L; Nam, D-H; Kim, S T

2009-01-01

Gliomatosis cerebri (GC) is defined as a diffuse neoplastic glial cell infiltration of the brain with the preservation of anatomical architecture and the sparing of neurons and can be classified into Type 1 (diffuse) and Type 2 (mass forming) GCs macroscopically. There is little information on subtypes of GC. The aim of this study was to evaluate the clinicopathologic findings of GCs and to compare the clinicopathologic findings between Type 1 and Type 2 GCs. A total of 33 cases of GC were obtained from pathology file of Samsung Medical Center. The diagnosis was based on magnetic resonance imaging findings and histological confirmation for all patients. Fifteen cases were classified into Type 1 and 18 were Type 2 based on the MR images. Clinical information included patients' age, sex, tumor extent, treatment modality and survival. Pathologic features included the amount of rod cells and cytologic anaplasia such as multinucleated tumor giant cells, endothelial cell proliferation, or mitosis. Immunohistochemical study was performed for GFAP, O1, Gal-C, Ki-67, and p53. Clinicopathologic comparison between subtypes and statistical analysis were performed. Median age at diagnosis was older (56 years) in Type 1 than in Type 2 (44 years). Male to female ratio was about 1.54:1. Mean survival time was shorter (21 months) in Type 2 than in Type 1 GCs (24 months) (p = 0.0447). Histologically, 33 cases of GC were classified into two histologic grades (low and high grade) by cytologic anaplasia. High-grade GC was more common in Type 2 than Type 1 (p = 0.027). Immunohistochemical results demonstrated that the infiltrating tumor cells were undifferentiated cells with astrocytic or oligodendroglial differentiation. Ki-67 labeling index was correlated with subtypes (p = 0.0096). Pathologic features were not correlated with survival. Type 1 and 2 GCs are somewhat different in clinical presentation and pathologic features. The age group, survival time, histologic grade, and Ki-67 labeling index were significantly correlated with subtypes ofGCs. Type 2 GC was correlated with poor survival but histologic grade was not.

Quantified hole concentration in AlGaN nanowires for high-performance ultraviolet emitters.

PubMed

Zhao, Chao; Ebaid, Mohamed; Zhang, Huafan; Priante, Davide; Janjua, Bilal; Zhang, Daliang; Wei, Nini; Alhamoud, Abdullah A; Shakfa, Mohammad Khaled; Ng, Tien Khee; Ooi, Boon S

2018-06-13

p-Type doping in wide bandgap and new classes of ultra-wide bandgap materials has long been a scientific and engineering problem. The challenges arise from the large activation energy of dopants and high densities of dislocations in materials. We report here, a significantly enhanced p-type conduction using high-quality AlGaN nanowires. For the first time, the hole concentration in Mg-doped AlGaN nanowires is quantified. The incorporation of Mg into AlGaN was verified by correlation with photoluminescence and Raman measurements. The open-circuit potential measurements further confirmed the p-type conductivity, while Mott-Schottky experiments measured a hole concentration of 1.3 × 1019 cm-3. These results from photoelectrochemical measurements allow us to design prototype ultraviolet (UV) light-emitting diodes (LEDs) incorporating the AlGaN quantum-disks-in-nanowire and an optimized p-type AlGaN contact layer for UV-transparency. The ∼335 nm LEDs exhibited a low turn-on voltage of 5 V with a series resistance of 32 Ω, due to the efficient p-type doping of the AlGaN nanowires. The bias-dependent Raman measurements further revealed the negligible self-heating of devices. This study provides an attractive solution to evaluate the electrical properties of AlGaN, which is applicable to other wide bandgap nanostructures. Our results are expected to open doors to new applications for wide and ultra-wide bandgap materials.

P-Type Transparent Cu-Alloyed ZnS Deposited at Room Temperature

DOE PAGES

Woods-Robinson, Rachel; Cooper, Jason K.; Xu, Xiaojie; ...

2016-03-16

All transparent conducting materials (TCMs) of technological practicality are n-type; the inferior conductivity of p-type TCMs has limited their adoption. Additionally, many relatively high-performing p-type TCMs require synthesis temperatures > 400 °C. Here, room-temperature pulsed laser deposition of copper-alloyed zinc sulfide (Cu x Zn 1- x S) thin films (0 ≤ x ≤ 0.75) is reported. For 0.09 ≤ x ≤ 0.35, Cu x Zn 1- x S has high p-type conductivity, up to 42 S cm -1 at x = 0.30, with an optical band gap tunable from ≈3.0–3.3 eV and transparency, averaged over the visible, of 50%–71% formore » 200–250 nm thick films. In this range, synchrotron X-ray and electron diffraction reveal a nanocrystalline ZnS structure. Secondary crystalline Cu y S phases are not observed, and at higher Cu concentrations, x > 0.45, films are amorphous and poorly conducting. Furthermore, within the TCM regime, the conductivity is temperature independent, indicating degenerate hole conduction. A decrease in lattice parameter with Cu content suggests that the hole conduction is due to substitutional incorporation of Cu onto Zn sites. This hole-conducting phase is embedded in a less conducting amorphous Cu y S, which dominates at higher Cu concentrations. Finally, the combination of high hole conductivity and optical transparency for the peak conductivity Cu x Zn 1- x S films is among the best reported to date for a room temperature deposited p-type TCM.« less

Screening of inorganic wide-bandgap p-type semiconductors for high performance hole transport layers in organic photovoltaic devices

NASA Astrophysics Data System (ADS)

Ginley, David; Zakutayev, Andriy; Garcia, Andreas; Widjonarko, Nicodemus; Ndione, Paul; Sigdel, Ajaya; Parilla, Phillip; Olson, Dana; Perkins, John; Berry, Joseph

2011-03-01

We will report on the development of novel inorganic hole transport layers (HTL) for organic photovoltaics (OPV). All the studied materials belong to the general class of wide-bandgap p-type oxide semiconductors. Potential candidates suitable for HTL applications include SnO, NiO, Cu2O (and related CuAlO2, CuCrO2, SrCu2O4 etc) and Co3O4 (and related ZnCo2O4, NiCo2O4, MgCo2O4 etc.). Materials have been optimized by high-throughput combinatorial approaches. The thin films were deposited by RF sputtering and pulsed laser deposition at ambient and elevated temperatures. Performance of the inorganic HTLs and that of the reference organic PEDOT:PSS HTL were compared by measuring the power conversion efficiencies and spectral responses of the P3HT/PCBM- and PCDTBT/PCBM-based OPV devices. Preliminary results indicate that Co3O4-based HTLs have performance comparable to that of our previously reported NiOs and PEDOT:PSS HTLs, leading to a power conversion efficiency of about 4 percent. The effect of composition and work function of the ternary materials on their performance in OPV devices is under investigation.

Inkjet-printed p-type nickel oxide thin-film transistor

NASA Astrophysics Data System (ADS)

Hu, Hailong; Zhu, Jingguang; Chen, Maosheng; Guo, Tailiang; Li, Fushan

2018-05-01

High-performance inkjet-printed nickel oxide thin-film transistors (TFTs) with Al2O3 high-k dielectric have been fabricated using a sol-gel precursor ink. The "coffee ring" effect during the printing process was facilely restrained by modifying the viscosity of the ink to control the outward capillary flow. The impacts on the device performance was studied in detail in consideration of annealing temperature of the nickel oxide film and the properties of dielectric layer. The optimized switching ability of the device were achieved at an annealing temperature of 280 °C on a 50-nm-thick Al2O3 dielectric layer, with a hole mobility of 0.78 cm2/V·s, threshold voltage of -0.6 V and on/off current ratio of 5.3 × 104. The as-printed p-type oxide TFTs show potential application in low-cost, large-area complementary electronic devices.

Sustained hole inversion layer in a wide-bandgap metal-oxide semiconductor with enhanced tunnel current

PubMed Central

Shoute, Gem; Afshar, Amir; Muneshwar, Triratna; Cadien, Kenneth; Barlage, Douglas

2016-01-01

Wide-bandgap, metal-oxide thin-film transistors have been limited to low-power, n-type electronic applications because of the unipolar nature of these devices. Variations from the n-type field-effect transistor architecture have not been widely investigated as a result of the lack of available p-type wide-bandgap inorganic semiconductors. Here, we present a wide-bandgap metal-oxide n-type semiconductor that is able to sustain a strong p-type inversion layer using a high-dielectric-constant barrier dielectric when sourced with a heterogeneous p-type material. A demonstration of the utility of the inversion layer was also investigated and utilized as the controlling element in a unique tunnelling junction transistor. The resulting electrical performance of this prototype device exhibited among the highest reported current, power and transconductance densities. Further utilization of the p-type inversion layer is critical to unlocking the previously unexplored capability of metal-oxide thin-film transistors, such applications with next-generation display switches, sensors, radio frequency circuits and power converters. PMID:26842997

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kang, Josephine, E-mail: jkang3@partners.org; Chen Minghui; Zhang Yuanye

Purpose: It has been recently shown that diabetes mellitus (DM) is significantly associated with the likelihood of presenting with high-grade prostate cancer (PCa) or Gleason score (GS) 8 to 10; however, whether this association holds for both Type 1 and 2 DM is unknown. In this study we evaluated whether DM Type 1, 2, or both are associated with high-grade PCa after adjusting for known predictors of high-grade disease. Methods and Materials: Between 1991 and 2010, a total of 15,330 men diagnosed with PCa and treated with radiation therapy were analyzed. A polychotomous logistic regression analysis was performed to evaluatemore » whether Type 1 or 2 DM was associated with odds of GS 7 or GS 8 to 10 compared with 6 or lower PCa, adjusting for African American race, age, prostate-specific antigen (PSA) level, and digital rectal examination findings. Results: Men with Type 1 DM (adjusted odds ratio [AOR], 2.05; 95% confidence interval [CI], 1.28-3.27; p = 0.003) or Type 2 DM (AOR, 1.58; 95% CI, 1.26-1.99; p < 0.001) were significantly more likely to be diagnosed with GS 8 to 10 PCa compared with nondiabetic men. However this was not true for GS 7, for which these respective results were AOR, 1.30; 95% CI, 0.93-1.82; p = 0.12 and AOR, 1.13; 95% CI, 0.98-1.32; p = 0.10. Conclusion: Type 1 and 2 DM were associated with a higher odds of being diagnosed with Gleason score 8 to 10 but not 7 PCa. Pending validation, men who are diagnosed with Type I DM with GS 7 or lower should be considered for additional workup to rule out occult high-grade disease.« less

General Practitioners' Barriers to Prescribe Physical Activity: The Dark Side of the Cluster Effects on the Physical Activity of Their Type 2 Diabetes Patients.

PubMed

Lanhers, Charlotte; Duclos, Martine; Guttmann, Aline; Coudeyre, Emmanuel; Pereira, Bruno; Ouchchane, Lemlih

2015-01-01

To describe barriers to physical activity (PA) in type 2 diabetes patients and their general practitioners (GPs), looking for practitioner's influence on PA practice of their patients. We conducted a cross-sectional study on GPs (n = 48) and their type 2 diabetes patients (n = 369) measuring respectively barriers to prescribe and practice PA using a self-assessment questionnaire: barriers to physical activity in diabetes (BAPAD). Statistical analysis was performed accounting hierarchical data structure. Similar practitioner's patients were considered a cluster sharing common patterns. The higher the patient's BAPAD score, the higher the barriers to PA, the higher the risk to declare practicing no PA (p<0.001), low frequency and low duration of PA (p<0.001). A high patient's BAPAD score was also associated with a higher risk to have HbA1c ≥7% (53 mmol/mol) (p = 0.001). The intra-class correlation coefficient between type 2 diabetes patients and GPs was 34%, indicating a high cluster effect. A high GP's BAPAD score, regarding the PA prescription, is predictive of a high BAPAD score with their patients, regarding their practice (p = 0.03). Type 2 diabetes patients with lower BAPAD score, thus lower barriers to physical activity, have a higher PA level and a better glycemic control. An important and deleterious cluster effect between GPs and their patients is demonstrated: the higher the GP's BAPAD score, the higher the type 2 diabetes patients' BAPAD score. This important cluster effect might designate GPs as a relevant lever for future interventions regarding patient's education towards PA and type 2 diabetes management.

Improved fabrication of focused single element P(VDF–TrFE) transducer for high frequency ultrasound applications

PubMed Central

Jeong, Jong Seob; Shung, K. Kirk

2013-01-01

We present an improved fabrication technique for the focused single element poly (vinylidene fluoride–trifluoroethylene) P(VDF–TrFE) transducer. In this work, a conductive epoxy for a backing layer was directly bonded to the 25 μm thick P(VDF–TrFE) film and thus made it easy to conform the aperture of the P(VDF–TrFE) transducer. Two prototype focused P(VDF–TrFE) transducers with disk- and ring-type aperture were fabricated and their performance was evaluated using the UBM (Ultrasound Biomicroscopy) system with a wire phantom. All transducers had a spherically focused aperture with a low f-number (focal depth/aperture size = 1). The center frequency of the disk-type P(VDF–TrFE) transducer was 23 MHz and −6 dB bandwidth was 102%. The ring-type P(VDF–TrFE) transducer had 20 MHz center frequency and −6 dB bandwidth of 103%. The measured pulse echo signal had reduced reverberation due to no additional adhesive layer between the P(VDF–TrFE) film and the backing layer. Hence, the proposed method is promising to fabricate a single element transducer using P(VDF–TrFE) film for high frequency applications. PMID:23021238

High-Performance Organic Light-Emitting Diode with Substitutionally Boron-Doped Graphene Anode.

PubMed

Wu, Tien-Lin; Yeh, Chao-Hui; Hsiao, Wen-Ting; Huang, Pei-Yun; Huang, Min-Jie; Chiang, Yen-Hsin; Cheng, Chien-Hong; Liu, Rai-Shung; Chiu, Po-Wen

2017-05-03

The hole-injection barrier between the anode and the hole-injection layer (HIL) is of critical importance to determine the device performance of organic light-emitting diodes (OLEDs). Here, we report on a record-high external quantum efficiency (EQE) (24.6% in green phosphorescence) of OLEDs fabricated on both rigid and flexible substrates, with the performance enhanced by the use of nearly defect-free and high-mobility boron-doped graphene as an effective anode and hexaazatriphenylene hexacarbonitrile as a new type of HIL. This new structure outperforms the existing graphene-based OLEDs, in which MoO 3 , AuCl 3 , or bis(trifluoromethanesulfonyl)amide are typically used as a doping source for the p-type graphene. The improvement of the OLED performance is attributed mainly to the appreciable increase of the hole conductivity in the nearly defect-free boron-doped monolayer graphene, along with the high work function achieved by the use of a newly developed hydrocarbon precursor containing boron in the graphene growth by chemical vapor deposition.

Evaluation of the clinical performance of the Abbott RealTime High-Risk HPV for carcinogenic HPV detection.

PubMed

Halfon, Philippe; Benmoura, Dominique; Agostini, Aubert; Khiri, Hacene; Penaranda, Guillaume; Martineau, Agnes; Blanc, Bernard

2010-08-01

Abbott RealTime (RT) High-Risk (HR) HPV assay is a new qualitative real-time polymerase chain reaction (PCR) based assay for the detection of 14 HR HPV DNA. The assay can differentiate between the infection by HPV 16, HPV 18 and non-HPV 16/18 types through the distinct fluorescent labels on the type specific probes. To evaluate the clinical performance of the Abbott RT HR HPV test, in comparison with biopsy, Hybrid Capture II (HCII), and Linear Array (LA), for detection of high-grade disease (CIN2+). The study population consisted of 143 women who were included in three referral gynecology clinics in Marseilles (France) between March 2007 and June 2008. The clinical performance of the RT HR HPV assay, performed on the fully automated m2000 system, was compared with HCII and LA. HR HPV positivity rate was similar for all tests (Abbott RT HR HPV and HCII, 62%, and LA 63%). All tests had high sensitivities and negative predictive values for CIN2+ detection (>90%). The agreement between HCII and Abbott RT HR HPV, and between HCII and LA were 93% (k=0.85) and 96% (k=0.91) respectively. As expected, HPV16 or HPV18 positivity was greater in advanced grades of disease, especially in CIN2+ patients: 85% in CIN2+ vs. 33% in

Schottky barrier amorphous silicon solar cell with thin doped region adjacent metal Schottky barrier

DOEpatents

Carlson, David E.; Wronski, Christopher R.

1979-01-01

A Schottky barrier amorphous silicon solar cell incorporating a thin highly doped p-type region of hydrogenated amorphous silicon disposed between a Schottky barrier high work function metal and the intrinsic region of hydrogenated amorphous silicon wherein said high work function metal and said thin highly doped p-type region forms a surface barrier junction with the intrinsic amorphous silicon layer. The thickness and concentration of p-type dopants in said p-type region are selected so that said p-type region is fully ionized by the Schottky barrier high work function metal. The thin highly doped p-type region has been found to increase the open circuit voltage and current of the photovoltaic device.

Successive and large-scale synthesis of InP/ZnS quantum dots in a hybrid reactor and their application to white LEDs

NASA Astrophysics Data System (ADS)

Kim, Kyungnam; Jeong, Sohee; Woo, Ju Yeon; Han, Chang-Soo

2012-02-01

We report successive and large-scale synthesis of InP/ZnS core/shell nanocrystal quantum dots (QDs) using a customized hybrid flow reactor, which is based on serial combination of a batch-type mixer and a flow-type furnace. InP cores and InP/ZnS core/shell QDs were successively synthesized in the hybrid reactor in a simple one-step process. In this reactor, the flow rate of the solutions was typically 1 ml min-1, 100 times larger than that of conventional microfluidic reactors. In order to synthesize high-quality InP/ZnS QDs, we controlled both the flow rate and the crystal growth temperature. Finally, we obtained high-quality InP/ZnS QDs in colors from bluish green to red, and we demonstrated that these core/shell QDs could be incorporated into white-light-emitting diode (LED) devices to improve color rendering performance.

Successive and large-scale synthesis of InP/ZnS quantum dots in a hybrid reactor and their application to white LEDs.

PubMed

Kim, Kyungnam; Jeong, Sohee; Woo, Ju Yeon; Han, Chang-Soo

2012-02-17

We report successive and large-scale synthesis of InP/ZnS core/shell nanocrystal quantum dots (QDs) using a customized hybrid flow reactor, which is based on serial combination of a batch-type mixer and a flow-type furnace. InP cores and InP/ZnS core/shell QDs were successively synthesized in the hybrid reactor in a simple one-step process. In this reactor, the flow rate of the solutions was typically 1 ml min(-1), 100 times larger than that of conventional microfluidic reactors. In order to synthesize high-quality InP/ZnS QDs, we controlled both the flow rate and the crystal growth temperature. Finally, we obtained high-quality InP/ZnS QDs in colors from bluish green to red, and we demonstrated that these core/shell QDs could be incorporated into white-light-emitting diode (LED) devices to improve color rendering performance.

Influence of smartphone use styles on typing performance and biomechanical exposure.

PubMed

Ko, Ping-Hsin; Hwang, Yaw-Huei; Liang, Huey-Wen

2016-06-01

Twenty-seven subjects completed 2-min typing tasks using four typing styles: right-hand holding/typing (S-thumb) and two-hand typing at three heights (B-low, B-mid and B-high). The styles had significant effects on typing performance, neck and elbow flexion and muscle activities of the right trapezius and several muscles of the right upper limb (p < 0.0001 by repeated-measure analysis of variance). The subjects typed the fewest words (error-adjusted characters per minute: 78) with the S-thumb style. S-thumb style resulted in similar flexion angles of the neck, elbow and wrist, but significantly increased muscle activities in all tested muscles compared with the B-mid style. Holding the phone high or low reduced the flexion angles of the neck and right elbow compared with the B-mid style, but the former styles increased the muscle activity of the right trapezius. Right-hand holding/typing was not a preferable posture due to high muscle activities and slow typing speed. Practitioner Summary: Right-hand holding/typing was not favoured, due to increased muscle activities and slower typing speed. Holding the phone high or low reduced the flexion angles of the neck and right elbow, but the former styles increased the muscle activity of the right trapezius compared with holding the phone at chest level.

Vincenzo LaSalvia | NREL

Science.gov Websites

;Utilization of Tabula Rasa to stabilize bulk lifetimes in n-Cz silicon for high-performance solar cell /SiOx/pc-Si passivated contacts to n-type Si solar cells." Presented at the 40th IEEE Photovoltaic , and P. Stradins. "Heterojunction rear passivated contact for high efficiency n-Cz Si solar cells

The morphologic and immunohistochemical spectrum of papillary renal cell carcinoma: study including 132 cases with pure type 1 and type 2 morphology as well as tumors with overlapping features.

PubMed

Chevarie-Davis, Myriam; Riazalhosseini, Yasser; Arseneault, Madeleine; Aprikian, Armen; Kassouf, Wassim; Tanguay, Simon; Latour, Mathieu; Brimo, Fadi

2014-07-01

Papillary renal cell carcinomas (pRCC) are classically divided into type 1 and 2 tumors. However, many cases do not fulfill all the criteria for either type. We describe the clinical, morphologic, and immunohistochemical (IHC) features of 132 pRCCs to better characterize the frequency and nature of tumors with overlapping features. Cases were reviewed and classified; IHC evaluation of CK7, EMA, TopoIIα, napsin A, and AMACR was performed on 95 cases. The frequencies of type 1, type 2, and "overlapping" pRCC were 25%, 28%, and 47%, respectively. The 2 categories of "overlapping" tumors were: (1) cases with bland cuboidal cells but no basophilic cytoplasm (type A); and (2) cases with predominantly type 1 histology admixed with areas showing prominent nucleoli (type B). The pathologic stage of "overlapping" cases showed concordance with type 1 tumors. Using the 2 discriminatory markers (CK7, EMA), "type A" cases were similar to type 1. Although the high-nuclear grade areas of "type B" tumors showed some staining differences from their low-nuclear grade counterpart, their IHC profile was closer to type 1. Single nucleotide polymorphism array results, although preliminary and restricted to only 9 cases (3 with overlapping features), also seemed to confirm those findings. In conclusion, we demonstrate that variations in cytoplasmic quality and/or presence of high-grade nuclei in tumors otherwise displaying features of type 1 pRCCs are similar in stage and IHC profile those with classic type 1 histology, suggesting that their spectrum might be wider than originally described.

High-performance hybrid complementary logic inverter through monolithic integration of a MEMS switch and an oxide TFT.

PubMed

Song, Yong-Ha; Ahn, Sang-Joon Kenny; Kim, Min-Wu; Lee, Jeong-Oen; Hwang, Chi-Sun; Pi, Jae-Eun; Ko, Seung-Deok; Choi, Kwang-Wook; Park, Sang-Hee Ko; Yoon, Jun-Bo

2015-03-25

A hybrid complementary logic inverter consisting of a microelectromechanical system switch as a promising alternative for the p-type oxide thin film transistor (TFT) and an n-type oxide TFT is presented for ultralow power integrated circuits. These heterogeneous microdevices are monolithically integrated. The resulting logic device shows a distinctive voltage transfer characteristic curve, very low static leakage, zero-short circuit current, and exceedingly high voltage gain. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Analysis of epitaxial drift field N on P silicon solar cells

NASA Technical Reports Server (NTRS)

Baraona, C. R.; Brandhorst, H. W., Jr.

1976-01-01

The performance of epitaxial drift field silicon solar cell structures having a variety of impurity profiles was calculated. These structures consist of a uniformly doped P-type substrate layer, and a P-type epitaxial drift field layer with a variety of field strengths. Several N-layer structures were modeled. A four layer solar cell model was used to calculate efficiency, open circuit voltage and short circuit current. The effect on performance of layer thickness, doping level, and diffusion length was determined. The results show that peak initial efficiency of 18.1% occurs for a drift field thickness of about 30 micron with the doping rising from 10 to the 17th power atoms/cu cm at the edge of the depletion region to 10 to the 18th power atoms/cu cm in the substrate. Stronger drift fields (narrow field regions) allowed very high performance (17% efficiency) even after irradiation to 3x10 to the 14th power 1 MeV electrons/sq cm.

Development of a (Hg, Cd)Te photodiode detector, Phase 2. [for 10.6 micron spectral region

NASA Technical Reports Server (NTRS)

1972-01-01

High speed sensitive (Hg,Cd)Te photodiode detectors operating in the 77 to 90 K temperature range have been developed for the 10.6 micron spectral region. P-N junctions formed by impurity (gold) diffusion in p-type (Hg, Cd) Te have been investigated. It is shown that the bandwidth and quantum efficiency of a diode are a constant for a fixed ratio of mobility/lifetime ratio of minority carriers. The minority carrier mobility and lifetime uniquely determine the bandwidth and quantum efficiency and indicate the shallow n on p (Hg,Cd) Te diodes are preferable as high performance, high frequency devices.

NREL Research Yields Significant Thermoelectric Performance | News | NREL

Science.gov Websites

Science paper, Large n- and p-type thermoelectric power factors from doped semiconducting single-walled negative charge carriers. These two types of material--called the p-type and the n-type legs, respectively heavily studied organic thermoelectric material, typically produce n-type materials that perform much

Long-term Outcome of Chondrosarcoma: A Single Institutional Experience.

PubMed

Bindiganavile, Srimanth; Han, Ilkyu; Yun, Ji Yeon; Kim, Han-Soo

2015-10-01

The prognostic factors of chondrosarcoma remain uncertain as only a few large studies with long-term follow-up have been reported. The aim of this study was to analyze oncological outcomes and prognostic factors. A retrospective review of oncological outcomes and prognostic factors was performed on 125 consecutive chondrosarcoma patients who underwent surgery at our institution. Overall survival was 91.6%±2.5%, 84.1%±3.8%, and 84.1%±3.8% at 5, 10, and 15 years respectively. Among the histological types, dedifferentiated type showed the worst survival (p < 0.001). As for conventional type chondrosarcoma, histologic grade and anatomical location predicted outcome, with high-grade with axial location having the worst outcome (p < 0.001). In contrast, low-grade chondrosarcoma of appendicular skeleton could be treated safely by intralesional curettage. Histological type was significantly associated with the outcome of chondrosarcoma. For the conventional type, histologic grade and anatomical location predicted outcome, with high-grade with axial location having the worst outcome.

Ultrathin Polyaniline-based Buffer Layer for Highly Efficient Polymer Solar Cells with Wide Applicability

PubMed Central

Zhao, Wenchao; Ye, Long; Zhang, Shaoqing; Fan, Bin; Sun, Mingliang; Hou, Jianhui

2014-01-01

Interfacial buffer layers often attribute the improved device performance in organic optoelectronic device. Herein, a water-soluble hydrochloric acid doped polyanilines (HAPAN) were utilized as p-type electrode buffer layer in highly efficient polymer solar cells (PSC) based on PBDTTT-EFT and several representative polymers. The PBDTTT-EFT-based conventional PSC featuring ultrathin HAPAN (1.3 nm) delivered high PCE approximately 9%, which is one of the highest values among conventional PSC devices. Moreover, ultrathin HAPAN also exhibited wide applicability in a variety of efficient photovoltaic polymers including PBDTTT-C-T, PTB7, PBDTBDD, PBTTDPP-T, PDPP3T and P3HT. The excellent performances were originated from the high transparency, small film roughness and suitable work function. PMID:25300365

Achieving high power factor and output power density in p-type half-Heuslers Nb1-xTixFeSb.

PubMed

He, Ran; Kraemer, Daniel; Mao, Jun; Zeng, Lingping; Jie, Qing; Lan, Yucheng; Li, Chunhua; Shuai, Jing; Kim, Hee Seok; Liu, Yuan; Broido, David; Chu, Ching-Wu; Chen, Gang; Ren, Zhifeng

2016-11-29

Improvements in thermoelectric material performance over the past two decades have largely been based on decreasing the phonon thermal conductivity. Enhancing the power factor has been less successful in comparison. In this work, a peak power factor of ∼106 μW⋅cm -1 ⋅K -2 is achieved by increasing the hot pressing temperature up to 1,373 K in the p-type half-Heusler Nb 0.95 Ti 0.05 FeSb. The high power factor subsequently yields a record output power density of ∼22 W⋅cm -2 based on a single-leg device operating at between 293 K and 868 K. Such a high-output power density can be beneficial for large-scale power generation applications.

Achieving high power factor and output power density in p-type half-Heuslers Nb1-xTixFeSb

PubMed Central

He, Ran; Kraemer, Daniel; Mao, Jun; Zeng, Lingping; Jie, Qing; Lan, Yucheng; Li, Chunhua; Shuai, Jing; Kim, Hee Seok; Liu, Yuan; Broido, David; Chu, Ching-Wu; Chen, Gang; Ren, Zhifeng

2016-01-01

Improvements in thermoelectric material performance over the past two decades have largely been based on decreasing the phonon thermal conductivity. Enhancing the power factor has been less successful in comparison. In this work, a peak power factor of ∼106 μW⋅cm−1⋅K−2 is achieved by increasing the hot pressing temperature up to 1,373 K in the p-type half-Heusler Nb0.95Ti0.05FeSb. The high power factor subsequently yields a record output power density of ∼22 W⋅cm−2 based on a single-leg device operating at between 293 K and 868 K. Such a high-output power density can be beneficial for large-scale power generation applications. PMID:27856743

RuO2 pH Sensor with Super-Glue-Inspired Reference Electrode

PubMed Central

Wajrak, Magdalena; Alameh, Kamal

2017-01-01

A pH-sensitive RuO2 electrode coated in a commercial cyanoacrylate adhesive typically exhibits very low pH sensitivity, and could be paired with a RuO2 working electrode as a differential type pH sensor. However, such sensors display poor performance in real sample matrices. A pH sensor employing a RuO2 pH-sensitive working electrode and a SiO2-PVB junction-modified RuO2 reference electrode is developed as an alternative high-performance solution. This sensor exhibits a performance similar to that of a commercial glass pH sensor in some common sample matrices, particularly, an excellent pH sensitivity of 55.7 mV/pH, a hysteresis as low as 2.7 mV, and a drift below 2.2 mV/h. The developed sensor structure opens the way towards the development of a simple, cost effective, and robust pH sensor for pH analysis in various sample matrices. PMID:28878182

RuO₂ pH Sensor with Super-Glue-Inspired Reference Electrode.

PubMed

Lonsdale, Wade; Wajrak, Magdalena; Alameh, Kamal

2017-09-06

A pH-sensitive RuO₂ electrode coated in a commercial cyanoacrylate adhesive typically exhibits very low pH sensitivity, and could be paired with a RuO₂ working electrode as a differential type pH sensor. However, such sensors display poor performance in real sample matrices. A pH sensor employing a RuO₂ pH-sensitive working electrode and a SiO₂-PVB junction-modified RuO₂ reference electrode is developed as an alternative high-performance solution. This sensor exhibits a performance similar to that of a commercial glass pH sensor in some common sample matrices, particularly, an excellent pH sensitivity of 55.7 mV/pH, a hysteresis as low as 2.7 mV, and a drift below 2.2 mV/h. The developed sensor structure opens the way towards the development of a simple, cost effective, and robust pH sensor for pH analysis in various sample matrices.

High-Performance Solid-State Thermionic Energy Conversion Based on 2D van der Waals Heterostructures: A First-Principles Study.

PubMed

Wang, Xiaoming; Zebarjadi, Mona; Esfarjani, Keivan

2018-06-18

Two-dimensional (2D) van der Waals heterostructures (vdWHs) have shown multiple functionalities with great potential in electronics and photovoltaics. Here, we show their potential for solid-state thermionic energy conversion and demonstrate a designing strategy towards high-performance devices. We propose two promising thermionic devices, namely, the p-type Pt-G-WSe 2 -G-Pt and n-type Sc-WSe 2 -MoSe 2 -WSe 2 -Sc. We characterize the thermionic energy conversion performance of the latter using first-principles GW calculations combined with real space Green's function (GF) formalism. The optimal barrier height and high thermal resistance lead to an excellent performance. The proposed device is found to have a room temperature equivalent figure of merit of 1.2 which increases to 3 above 600 K. A high performance with cooling efficiency over 30% of the Carnot efficiency above 450 K is achieved. Our designing and characterization method can be used to pursue other potential thermionic devices based on vdWHs.

Associations Between Physical Activity and Depressive Symptoms by Weight Status Among Adults With Type 2 Diabetes: Results From Diabetes MILES-Australia.

PubMed

Craike, Melinda J; Mosely, Kylie; Browne, Jessica L; Pouwer, Frans; Speight, Jane

2017-03-01

To examine associations between physical activity (PA) and depressive symptoms among adults with type 2 diabetes mellitus (Type 2 DM), and whether associations varied according to weight status. Diabetes MILES-Australia is a national survey of adults with diabetes, focused on behavioral and psychosocial issues. Data from 705 respondents with Type 2 DM were analyzed, including: demographic and clinical characteristics, PA (IPAQ-SF), depressive symptoms (PHQ-9), and BMI (self-reported height and weight). Data analysis was performed using ANCOVA. Respondents were aged 59 ± 8 years; 50% women. PA was negatively associated with depressive symptoms for the overall sample (η p 2 = 0.04,P < .001) and all weight categories separately: healthy (η p 2 0.11 P = .041,), overweight (η p 2 = 0.04, P = .025) and obese (η p 2 = 0.03, P = .007). For people who were healthy (BMI 18.5 to 24.9) or overweight (BMI 25 to 29.9), high amounts of PA were significantly associated with fewer depressive symptoms; for adults who were obese (BMI ≥ 30) however, both moderate and high amounts were associated with fewer depressive symptoms. PA is associated with fewer depressive symptoms among adults with Type 2DM, however the amount of PA associated with fewer depressive symptoms varies according to weight status. Lower amounts of PA might be required for people who are obese to achieve meaningful reductions in depressive symptoms compared with those who are healthy weight or overweight. Further research is needed to establish the direction of the relationship between PA and depressive symptoms.

A computerized assessment to compare the impact of standard, stereoscopic, and high-definition laparoscopic monitor displays on surgical technique.

PubMed

Feng, Chuan; Rozenblit, Jerzy W; Hamilton, Allan J

2010-11-01

Surgeons performing laparoscopic surgery have strong biases regarding the quality and nature of the laparoscopic video monitor display. In a comparative study, we used a unique computerized sensing and analysis system to evaluate the various types of monitors employed in laparoscopic surgery. We compared the impact of different types of monitor displays on an individual's performance of a laparoscopic training task which required the subject to move the instrument to a set of targets. Participants (varying from no laparoscopic experience to board-certified surgeons) were asked to perform the assigned task while using all three display systems, which were randomly assigned: a conventional laparoscopic monitor system (2D), a high-definition monitor system (HD), and a stereoscopic display (3D). The effects of monitor system on various performance parameters (total time consumed to finish the task, average speed, and movement economy) were analyzed by computer. Each of the subjects filled out a subjective questionnaire at the end of their training session. A total of 27 participants completed our study. Performance with the HD monitor was significantly slower than with either the 3D or 2D monitor (p < 0.0001). Movement economy with the HD monitor was significantly reduced compared with the 3D (p < 0.0004) or 2D (p < 0.0001) monitor. In terms of average time required to complete the task, performance with the 3D monitor was significantly faster than with the HD (p < 0.0001) or 2D (p < 0.0086) monitor. However, the HD system was the overwhelming favorite according to subjective evaluation. Computerized sensing and analysis is capable of quantitatively assessing the seemingly minor effect of monitor display on surgical training performance. The study demonstrates that, while users expressed a decided preference for HD systems, actual quantitative analysis indicates that HD monitors offer no statistically significant advantage and may even worsen performance compared with standard 2D or 3D laparoscopic monitors.

Effects of dietary starch types on growth performance, meat quality and myofibre type of finishing pigs.

PubMed

Li, Y J; Li, J L; Zhang, L; Gao, F; Zhou, G H

2017-09-01

To investigate the effects of dietary starch types on growth performance and meat quality of finishing pigs, ninety barrows (68.0±2.0kg) were randomly allotted to three experimental diets with five replicates of six pigs, containing pure waxy maize starch (WMS), nonwaxy maize starch (NMS) and pea starch (PS) (amylose/amylopectin were 0.07, 0.19 and 0.28 respectively). Compared with WMS diet, PS diet increased the average daily gain, loin eye area, pH 45 value, NMR transverse relaxation (T 2 ) 2 peak area ratio and sarcoplasmic protein solubility, decreased the feed to gain ratio, back fat, drip loss, cooking loss and T 23 peak area ratio (P<0.05). Moreover, PS diet increased the myosin heavy-chain (MyHC)-I and IIa levels, decreased the MyHC-IIb level, decreased the miR23a level and increased its target gene level, increased the miR499 level and decreased its target gene level (P<0.05). Diet with high amylose content might be beneficial to the growth performance and meat quality of finishing pigs. Copyright © 2017 Elsevier Ltd. All rights reserved.

High Performance Oxides-Based Thermoelectric Materials

NASA Astrophysics Data System (ADS)

Ren, Guangkun; Lan, Jinle; Zeng, Chengcheng; Liu, Yaochun; Zhan, Bin; Butt, Sajid; Lin, Yuan-Hua; Nan, Ce-Wen

2015-01-01

Thermoelectric materials have attracted much attention due to their applications in waste-heat recovery, power generation, and solid state cooling. In comparison with thermoelectric alloys, oxide semiconductors, which are thermally and chemically stable in air at high temperature, are regarded as the candidates for high-temperature thermoelectric applications. However, their figure-of-merit ZT value has remained low, around 0.1-0.4 for more than 20 years. The poor performance in oxides is ascribed to the low electrical conductivity and high thermal conductivity. Since the electrical transport properties in these thermoelectric oxides are strongly correlated, it is difficult to improve both the thermoelectric power and electrical conductivity simultaneously by conventional methods. This review summarizes recent progresses on high-performance oxide-based thermoelectric bulk-materials including n-type ZnO, SrTiO3, and In2O3, and p-type Ca3Co4O9, BiCuSeO, and NiO, enhanced by heavy-element doping, band engineering and nanostructuring.

Relationship between grip, pinch strengths and anthropometric variables, types of pitch throwing among Japanese high school baseball pitchers.

PubMed

Tajika, Tsuyoshi; Kobayashi, Tsutomu; Yamamoto, Atsushi; Shitara, Hitoshi; Ichinose, Tsuyoshi; Shimoyama, Daisuke; Okura, Chisa; Kanazawa, Saeko; Nagai, Ayako; Takagishi, Kenji

2015-03-01

Grip and pinch strength are crucially important attributes and standard parameters related to the functional integrity of the hand. It seems significant to investigate normative data for grip and pinch strength of baseball players to evaluate their performance and condition. Nevertheless, few reports have explained the association between grip and pinch strength and anthropometric variables and types of pitch throwing for baseball pitchers. The aim of this study was to measure and evaluate clinical normative data for grip and tip, key, palmar pinch strength and to assess the relationship between these data and anthropometric variables and types of pitch throwing among Japanese high-school baseball pitchers. One hundred-thirty three healthy high school baseball pitchers were examined and had completed a self-administered questionnaire including items related to age, hand dominance, throwing ratio of type of pitch. A digital dynamometer was used to measure grip strength and a pinch gauge to measure tip, key and palmer pinch in both dominant and nondominant side. Body composition was measured by the multi frequency segmental body composition analyzer. Grip strength and tip and palmer pinch strength in dominant side were statistically greater than them in nondominant side (P < 0.05). There were significant associations between grip strength and height (r = 0.33, P < 0.001), body mass (r = 0.50, P < 0.001), BMI (r = 0.37, P < 0.001), muscle mass of upper extremity (r = 0.56, P < 0.001), fat free mass (r = 0.57, P < 0.001), fat mass (r = 0.22, P < 0.05) in dominant side. A stepwise multiple regression analysis revealed that fat free mass and tip, palmer, key pinch strength were predictors of grip strength in dominant side. No statistical significant correlations were found between the throwing ratio of types of pitches thrown and grip strength and tip, key, palmar pinch strength. Our result provides normative values and evidences for grip and pinch strengths in high school baseball pitchers.

Volume vs. intensity in the training of competitive swimmers.

PubMed

Faude, O; Meyer, T; Scharhag, J; Weins, F; Urhausen, A; Kindermann, W

2008-11-01

The present study aimed at comparing a high-volume, low-intensity vs. low-volume, high-intensity swim training. In a randomized cross-over design, 10 competitive swimmers performed two different 4-week training periods, each followed by an identical taper week. One training period was characterized by a high-training volume (HVT) whereas high-intensity training was prevalent during the other program (HIT). Before, after two and four weeks and after the taper week subjects performed psychometric and performance testing: profile of mood states (POMS), incremental swimming test (determination of individual anaerobic threshold, IAT), 100 m and 400 m. A small significant increase in IAT was observed after taper periods compared to pre-training (+ 0.01 m/s; p = 0.01). Maximal 100-m and 400-m times were not significantly affected by training. The POMS subscore of "vigor" decreased slightly after both training periods (p = 0.06). None of the investigated parameters showed a significant interaction between test-time and training type (p > 0.13). Nearly all (83 %) subjects swam personal best times during the 3 months after each training cycle. It is concluded that, for a period of 4 weeks, high-training volumes have no advantage compared to high-intensity training of lower volume.

Acceptor-modulated optical enhancements and band-gap narrowing in ZnO thin films

NASA Astrophysics Data System (ADS)

Hassan, Ali; Jin, Yuhua; Irfan, Muhammad; Jiang, Yijian

2018-03-01

Fermi-Dirac distribution for doped semiconductors and Burstein-Moss effect have been correlated first time to figure out the conductivity type of ZnO. Hall Effect in the Van der Pauw configuration has been applied to reconcile our theoretical estimations which evince our assumption. Band-gap narrowing has been found in all p-type samples, whereas blue Burstein-Moss shift has been recorded in the n-type films. Atomic Force Microscopic (AFM) analysis shows that both p-type and n-type films have almost same granular-like structure with minor change in average grain size (˜ 6 nm to 10 nm) and surface roughness rms value 3 nm for thickness ˜315 nm which points that grain size and surface roughness did not play any significant role in order to modulate the conductivity type of ZnO. X-ray diffraction (XRD), Energy Dispersive X-ray Spectroscopy (EDS) and X-ray Photoelectron Spectroscopy (XPS) have been employed to perform the structural, chemical and elemental analysis. Hexagonal wurtzite structure has been observed in all samples. The introduction of nitrogen reduces the crystallinity of host lattice. 97% transmittance in the visible range with 1.4 × 107 Ω-1cm-1 optical conductivity have been detected. High absorption value in the ultra-violet (UV) region reveals that NZOs thin films can be used to fabricate next-generation high-performance UV detectors.

A comparative analysis between the effects of galactose and glucose supplementation on endurance performance.

PubMed

Macdermid, Paul W; Stannard, Stephen; Rankin, Dean; Shillington, David

2012-02-01

To determine beneficial effects of short-term galactose (GAL) supplementation over a 50:50 glucose-maltodextrin (GLUC) equivalent on self-paced endurance cycling performance. On 2 separate occasions, subjects performed a 100-km self-paced time trial (randomized and balanced order). This was interspersed with four 1-km and four 4-km maximal efforts reflecting the physical requirements of racing. Before each trial 38±3 g of GAL or GLUC was ingested in a 6% concentrate fluid form 1 hr preexercise and then during exercise at a rate of 37±3 g/hr. Performance variables were recorded for all 1- and 4-km efforts, all interspersed intervals, and the total 100-km distance. Noninvasive indicators of work intensity (heart rate [HR] and rating of perceived exertion) were also recorded. Times taken to complete the 100-km performance trial were 8,298±502 and 8,509±578 s (p=.132), with mean power outputs of 271±37 and 256±45 W (p=.200), for GAL and GLUC, respectively. Mean HR did not differ (GAL 157±7 and GLUC 157±7 beats/min, p=.886). A main effect of carbohydrate (CHO) type on time to complete 4-km efforts occurred, with no CHO Type×Effort Order interaction observed. No main effect of CHO type or interaction of CHO Type×Sequential Order occurred for 1-km efforts. A 6% GAL drink does not enhance performance time during a self-paced cycling performance trial in highly trained endurance cyclists compared with a formula typically used by endurance athletes but may improve the ability to produce intermediate self-paced efforts.

Cogging Torque Reduction Techniques for Spoke-type IPMSM

NASA Astrophysics Data System (ADS)

Bahrim, F. S.; Sulaiman, E.; Kumar, R.; Jusoh, L. I.

2017-08-01

A spoke-type interior permanent magnet synchronous motor (IPMSM) is extending its tentacles in industrial arena due to good flux-weakening capability and high power density. In many of the application, high strength of permanent magnet causes the undesirable effects of high cogging torque that can aggravate performance of the motor. High cogging torque is significantly produced by IPMSM due to the similar length and the effectiveness of the magnetic air-gap. The address of this study is to analyze and compare the cogging torque effect and performance of four common techniques for cogging torque reduction such as skewing, notching, pole pairing and rotor pole pairing. With the aid of 3-D finite element analysis (FEA) by JMAG software, a 6S-4P Spoke-type IPMSM with various rotor-PM configurations has been designed. As a result, the cogging torque effect reduced up to 69.5% for skewing technique, followed by 31.96%, 29.6%, and 17.53% by pole pairing, axial pole pairing and notching techniques respectively.

Evidence for ACTN3 as a Speed Gene in Isolated Human Muscle Fibers.

PubMed

Broos, Siacia; Malisoux, Laurent; Theisen, Daniel; van Thienen, Ruud; Ramaekers, Monique; Jamart, Cécile; Deldicque, Louise; Thomis, Martine A; Francaux, Marc

2016-01-01

To examine the effect of α-actinin-3 deficiency due to homozygosity for the ACTN3 577X-allele on contractile and morphological properties of fast muscle fibers in non-athletic young men. A biopsy was taken from the vastus lateralis of 4 RR and 4 XX individuals to test for differences in morphologic and contractile properties of single muscle fibers. The cross-sectional area of the fiber and muscle fiber composition was determined using standard immunohistochemistry analyses. Skinned single muscle fibers were subjected to active tests to determine peak normalized force (P0), maximal unloading velocity (V0) and peak power. A passive stretch test was performed to calculate Young's Modulus and hysteresis to assess fiber visco-elasticity. No differences were found in muscle fiber composition. The cross-sectional area of type IIa and IIx fibers was larger in RR compared to XX individuals (P<0.001). P0 was similar in both groups over all fiber types. A higher V0 was observed in type IIa fibers of RR genotypes (P<0.001) but not in type I fibers. The visco-elasticity as determined by Young's Modulus and hysteresis was unaffected by fiber type or genotype. The greater V0 and the larger fast fiber CSA in RR compared to XX genotypes likely contribute to enhanced whole muscle performance during high velocity contractions.

Highly efficient bilayer interface exciplex for yellow organic light-emitting diode.

PubMed

Hung, Wen-Yi; Fang, Guan-Cheng; Chang, Yuh-Chia; Kuo, Ting-Yi; Chou, Pi-Tai; Lin, Shih-Wei; Wong, Ken-Tsung

2013-08-14

A simple three-layer interfacial-type yellow emission exciplex device with an external quantum efficiency as high as 7.7% has been successfully achieved by combining conformation compatible C3-symmetric hole-transporting TCTA and electron-transporting 3P-T2T. The excellent and balanced charge-transporting properties of TCTA and 3P-T2T and the large energy-levels offset (0.8 eV) of TCTA/3P-T2T interface play important roles for the efficient exciplexes formation, which are effectively confined around the interfacial region due to the high triplet energies (2.85 eV) of TCTA and 3P-T2T. The high-performance OLED was believed to be from the effective harvest of exciplex triplet excitons via reverse intersystem crossing process.

Localized Vibrations of Bi Bilayer Leading to Ultralow Lattice Thermal Conductivity and High Thermoelectric Performance in Weak Topological Insulator n-Type BiSe.

PubMed

Samanta, Manisha; Pal, Koushik; Pal, Provas; Waghmare, Umesh V; Biswas, Kanishka

2018-05-02

Realization of high thermoelectric performance in n-type semiconductors is of imperative need on account of the dearth of efficient n-type thermoelectric materials compared to the p-type counterpart. Moreover, development of efficient thermoelectric materials based on Te-free compounds is desirable because of the scarcity of Te in the Earth's crust. Herein, we report the intrinsic ultralow thermal conductivity and high thermoelectric performance near room temperature in n-type BiSe, a Te-free solid, which recently has emerged as a weak topological insulator. BiSe possesses a layered structure consisting of a bismuth bilayer (Bi 2 ) sandwiched between two Bi 2 Se 3 quintuple layers [Se-Bi-Se-Bi-Se], resembling natural heterostructure. High thermoelectric performance of BiSe is realized through the ultralow lattice thermal conductivity (κ lat of ∼0.6 W/mK at 300 K), which is significantly lower than that of Bi 2 Se 3 (κ lat of ∼1.8 W/mK at 300 K), although both of them belong to the same layered homologous family (Bi 2 ) m (Bi 2 Se 3 ) n . Phonon dispersion calculated from first-principles and the experimental low-temperature specific heat data indicate that soft localized vibrations of bismuth bilayer in BiSe are responsible for its ultralow κ lat . These low energy optical phonon branches couple strongly with the heat carrying acoustic phonons, and consequently suppress the phonon mean free path leading to low κ lat . Further optimization of thermoelectric properties of BiSe through Sb substitution and spark plasma sintering (SPS) results in high ZT ∼ 0.8 at 425 K along the pressing direction, which is indeed remarkable among Te-free n-type thermoelectric materials near room temperature.

Ultra-doped n-type germanium thin films for sensing in the mid-infrared

PubMed Central

Prucnal, Slawomir; Liu, Fang; Voelskow, Matthias; Vines, Lasse; Rebohle, Lars; Lang, Denny; Berencén, Yonder; Andric, Stefan; Boettger, Roman; Helm, Manfred; Zhou, Shengqiang; Skorupa, Wolfgang

2016-01-01

A key milestone for the next generation of high-performance multifunctional microelectronic devices is the monolithic integration of high-mobility materials with Si technology. The use of Ge instead of Si as a basic material in nanoelectronics would need homogeneous p- and n-type doping with high carrier densities. Here we use ion implantation followed by rear side flash-lamp annealing (r-FLA) for the fabrication of heavily doped n-type Ge with high mobility. This approach, in contrast to conventional annealing procedures, leads to the full recrystallization of Ge films and high P activation. In this way single crystalline Ge thin films free of defects with maximum attained carrier concentrations of 2.20 ± 0.11 × 1020 cm−3 and carrier mobilities above 260 cm2/(V·s) were obtained. The obtained ultra-doped Ge films display a room-temperature plasma frequency above 1,850 cm−1, which enables to exploit the plasmonic properties of Ge for sensing in the mid-infrared spectral range. PMID:27282547

High performance printed oxide field-effect transistors processed using photonic curing.

PubMed

Garlapati, Suresh Kumar; Marques, Gabriel Cadilha; Gebauer, Julia Susanne; Dehm, Simone; Bruns, Michael; Winterer, Markus; Tahoori, Mehdi Baradaran; Aghassi-Hagmann, Jasmin; Hahn, Horst; Dasgupta, Subho

2018-06-08

Oxide semiconductors are highly promising candidates for the most awaited, next-generation electronics, namely, printed electronics. As a fabrication route for the solution-processed/printed oxide semiconductors, photonic curing is becoming increasingly popular, as compared to the conventional thermal curing method; the former offers numerous advantages over the latter, such as low process temperatures and short exposure time and thereby, high throughput compatibility. Here, using dissimilar photonic curing concepts (UV-visible light and UV-laser), we demonstrate facile fabrication of high performance In 2 O 3 field-effect transistors (FETs). Beside the processing related issues (temperature, time etc.), the other known limitation of oxide electronics is the lack of high performance p-type semiconductors, which can be bypassed using unipolar logics from high mobility n-type semiconductors alone. Interestingly, here we have found that our chosen distinct photonic curing methods can offer a large variation in threshold voltage, when they are fabricated from the same precursor ink. Consequently, both depletion and enhancement-mode devices have been achieved which can be used as the pull-up and pull-down transistors in unipolar inverters. The present device fabrication recipe demonstrates fast processing of low operation voltage, high performance FETs with large threshold voltage tunability.

High performance printed oxide field-effect transistors processed using photonic curing

NASA Astrophysics Data System (ADS)

Garlapati, Suresh Kumar; Cadilha Marques, Gabriel; Gebauer, Julia Susanne; Dehm, Simone; Bruns, Michael; Winterer, Markus; Baradaran Tahoori, Mehdi; Aghassi-Hagmann, Jasmin; Hahn, Horst; Dasgupta, Subho

2018-06-01

Oxide semiconductors are highly promising candidates for the most awaited, next-generation electronics, namely, printed electronics. As a fabrication route for the solution-processed/printed oxide semiconductors, photonic curing is becoming increasingly popular, as compared to the conventional thermal curing method; the former offers numerous advantages over the latter, such as low process temperatures and short exposure time and thereby, high throughput compatibility. Here, using dissimilar photonic curing concepts (UV–visible light and UV-laser), we demonstrate facile fabrication of high performance In2O3 field-effect transistors (FETs). Beside the processing related issues (temperature, time etc.), the other known limitation of oxide electronics is the lack of high performance p-type semiconductors, which can be bypassed using unipolar logics from high mobility n-type semiconductors alone. Interestingly, here we have found that our chosen distinct photonic curing methods can offer a large variation in threshold voltage, when they are fabricated from the same precursor ink. Consequently, both depletion and enhancement-mode devices have been achieved which can be used as the pull-up and pull-down transistors in unipolar inverters. The present device fabrication recipe demonstrates fast processing of low operation voltage, high performance FETs with large threshold voltage tunability.

Cellules photovoltaïques à base de semi-conducteurs organiques

NASA Astrophysics Data System (ADS)

Videlot, C.; Fichou, D.; Garnier, F.

1998-06-01

We describe here the elaboration and performances of photovoltaic cells using organic p type (pentacene) and n type (perylene) semiconductors in a pn heterojunction configuration. Nous décrivons ici l'élaboration et les performances de cellules photovoltaïques à base de semi-conducteurs organiques de type p (pentacène) et de type n (pérylène) dans une hétérojonction pn.

Fabrication of WS2/GaN p-n Junction by Wafer-Scale WS2 Thin Film Transfer

PubMed Central

Yu, Yang; Fong, Patrick W. K.; Wang, Shifeng; Surya, Charles

2016-01-01

High quality wafer-scale free-standing WS2 grown by van der Waals rheotaxy (vdWR) using Ni as a texture promoting layer is reported. The microstructure of vdWR grown WS2 was significantly modified from mixture of crystallites with their c-axes both parallel to (type I) and perpendicular to (type II) the substrate to large type II crystallites. Wafer-scale transfer of vdWR grown WS2 onto different substrates by an etching-free technique was demonstrated for the first time that utilized the hydrophobic property of WS2 and hydrophilic property of sapphire. Our results show that vdWR is a reliable technique to obtain type-II textured crystallites in WS2, which is the key factor for the wafer-scale etching-free transfer. The transferred films were found to be free of observable wrinkles, cracks, or polymer residues. High quality p-n junctions fabricated by room-temperature transfer of the p-type WS2 onto an n-type GaN was demonstrated with a small leakage current density of 29.6 μA/cm2 at −1 V which shows superior performances compared to the directly grown WS2/GaN heterojunctions. PMID:27897210

Fabrication of WS2/GaN p-n Junction by Wafer-Scale WS2 Thin Film Transfer.

PubMed

Yu, Yang; Fong, Patrick W K; Wang, Shifeng; Surya, Charles

2016-11-29

High quality wafer-scale free-standing WS 2 grown by van der Waals rheotaxy (vdWR) using Ni as a texture promoting layer is reported. The microstructure of vdWR grown WS 2 was significantly modified from mixture of crystallites with their c-axes both parallel to (type I) and perpendicular to (type II) the substrate to large type II crystallites. Wafer-scale transfer of vdWR grown WS 2 onto different substrates by an etching-free technique was demonstrated for the first time that utilized the hydrophobic property of WS 2 and hydrophilic property of sapphire. Our results show that vdWR is a reliable technique to obtain type-II textured crystallites in WS 2 , which is the key factor for the wafer-scale etching-free transfer. The transferred films were found to be free of observable wrinkles, cracks, or polymer residues. High quality p-n junctions fabricated by room-temperature transfer of the p-type WS 2 onto an n-type GaN was demonstrated with a small leakage current density of 29.6 μA/cm 2 at -1 V which shows superior performances compared to the directly grown WS 2 /GaN heterojunctions.

Medication adherence, comorbidities, and health risk impacts on workforce absence and job performance.

PubMed

Loeppke, Ronald; Haufle, Vince; Jinnett, Kim; Parry, Thomas; Zhu, Jianping; Hymel, Pamela; Konicki, Doris

2011-06-01

To understand impacts of medication adherence, comorbidities, and health risks on workforce absence and job performance. Retrospective observational study using employees' medical/pharmacy claims and self-reported health risk appraisals. Statin medication adherence in individuals with Coronary Artery Disease was significant predictor (P < 0.05) of decreasing absenteeism. Insulin, oral hypoglycemic, or metformin medication adherence in type 2 diabetics was significant (P < 0.05) predictor of decreasing job performance. Number of comorbidities was found as significant (P < 0.5) predictor of absenteeism in five of nine subsamples. Significant links (P < 0.05) between high health risks and lower job performance were found across all nine subsamples. Results suggest integrated health and productivity management strategies should include an emphasis on primary and secondary prevention to reduce health risks in addition to tertiary prevention efforts of disease management and medication management.

A cycling workstation to facilitate physical activity in office settings.

PubMed

Elmer, Steven J; Martin, James C

2014-07-01

Facilitating physical activity during the workday may help desk-bound workers reduce risks associated with sedentary behavior. We 1) evaluated the efficacy of a cycling workstation to increase energy expenditure while performing a typing task and 2) fabricated a power measurement system to determine the accuracy and reliability of an exercise cycle. Ten individuals performed 10 min trials of sitting while typing (SIT type) and pedaling while typing (PED type). Expired gases were recorded and typing performance was assessed. Metabolic cost during PED type was ∼ 2.5 × greater compared to SIT type (255 ± 14 vs. 100 ± 11 kcal h(-1), P < 0.01). Typing time and number of typing errors did not differ between PED type and SIT type (7.7 ± 1.5 vs. 7.6 ± 1.6 min, P = 0.51, 3.3 ± 4.6 vs. 3.8 ± 2.7 errors, P = 0.80). The exercise cycle overestimated power by 14-138% compared to actual power but actual power was reliable (r = 0.998, P < 0.01). A cycling workstation can facilitate physical activity without compromising typing performance. The exercise cycle's inaccuracy could be misleading to users. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Gate-tunable carbon nanotube-MoS2 heterojunction p-n diode.

PubMed

Jariwala, Deep; Sangwan, Vinod K; Wu, Chung-Chiang; Prabhumirashi, Pradyumna L; Geier, Michael L; Marks, Tobin J; Lauhon, Lincoln J; Hersam, Mark C

2013-11-05

The p-n junction diode and field-effect transistor are the two most ubiquitous building blocks of modern electronics and optoelectronics. In recent years, the emergence of reduced dimensionality materials has suggested that these components can be scaled down to atomic thicknesses. Although high-performance field-effect devices have been achieved from monolayered materials and their heterostructures, a p-n heterojunction diode derived from ultrathin materials is notably absent and constrains the fabrication of complex electronic and optoelectronic circuits. Here we demonstrate a gate-tunable p-n heterojunction diode using semiconducting single-walled carbon nanotubes (SWCNTs) and single-layer molybdenum disulfide as p-type and n-type semiconductors, respectively. The vertical stacking of these two direct band gap semiconductors forms a heterojunction with electrical characteristics that can be tuned with an applied gate bias to achieve a wide range of charge transport behavior ranging from insulating to rectifying with forward-to-reverse bias current ratios exceeding 10(4). This heterojunction diode also responds strongly to optical irradiation with an external quantum efficiency of 25% and fast photoresponse <15 μs. Because SWCNTs have a diverse range of electrical properties as a function of chirality and an increasing number of atomically thin 2D nanomaterials are being isolated, the gate-tunable p-n heterojunction concept presented here should be widely generalizable to realize diverse ultrathin, high-performance electronics and optoelectronics.

Gate-tunable carbon nanotube–MoS2 heterojunction p-n diode

PubMed Central

Jariwala, Deep; Sangwan, Vinod K.; Wu, Chung-Chiang; Prabhumirashi, Pradyumna L.; Geier, Michael L.; Marks, Tobin J.; Lauhon, Lincoln J.; Hersam, Mark C.

2013-01-01

The p-n junction diode and field-effect transistor are the two most ubiquitous building blocks of modern electronics and optoelectronics. In recent years, the emergence of reduced dimensionality materials has suggested that these components can be scaled down to atomic thicknesses. Although high-performance field-effect devices have been achieved from monolayered materials and their heterostructures, a p-n heterojunction diode derived from ultrathin materials is notably absent and constrains the fabrication of complex electronic and optoelectronic circuits. Here we demonstrate a gate-tunable p-n heterojunction diode using semiconducting single-walled carbon nanotubes (SWCNTs) and single-layer molybdenum disulfide as p-type and n-type semiconductors, respectively. The vertical stacking of these two direct band gap semiconductors forms a heterojunction with electrical characteristics that can be tuned with an applied gate bias to achieve a wide range of charge transport behavior ranging from insulating to rectifying with forward-to-reverse bias current ratios exceeding 104. This heterojunction diode also responds strongly to optical irradiation with an external quantum efficiency of 25% and fast photoresponse <15 μs. Because SWCNTs have a diverse range of electrical properties as a function of chirality and an increasing number of atomically thin 2D nanomaterials are being isolated, the gate-tunable p-n heterojunction concept presented here should be widely generalizable to realize diverse ultrathin, high-performance electronics and optoelectronics. PMID:24145425

AgI alloying in SnTe boosts the thermoelectric performance via simultaneous valence band convergence and carrier concentration optimization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Banik, Ananya; Biswas, Kanishka, E-mail: kanishka@jncasr.ac.in

SnTe, a Pb-free analogue of PbTe, was earlier assumed to be a poor thermoelectric material due to excess p-type carrier concentration and large energy separation between light and heavy hole valence bands. Here, we report the enhancement of the thermoelectric performance of p-type SnTe by Ag and I co-doping. AgI (1–6 mol%) alloying in SnTe modulates its electronic structure by increasing the band gap of SnTe, which results in decrease in the energy separation between its light and heavy hole valence bands, thereby giving rise to valence band convergence. Additionally, iodine doping in the Te sublattice of SnTe decreases themore » excess p-type carrier concentration. Due to significant decrease in hole concentration and reduction of the energy separation between light and heavy hole valence bands, significant enhancement in Seebeck coefficient was achieved at the temperature range of 600–900 K for Sn{sub 1−x}Ag{sub x}Te{sub 1−x}I{sub x} samples. A maximum thermoelectric figure of merit, zT, of ~1.05 was achieved at 860 K in high quality crystalline ingot of p-type Sn{sub 0.95}Ag{sub 0.05}Te{sub 0.95}I{sub 0.05}. - Graphical abstract: Significant decrease in hole concentration and reduction of the energy separation between light and heavy hole valence bands resulted in a maximum thermoelectric figure of merit, zT, of ~1.05 at 860 K in high quality crystalline ingot of p-type Sn{sub 0.95}Ag{sub 0.05}Te{sub 0.95}I{sub 0.05}. - Highlights: • AgI alloying in SnTe increases the principle band gap. • Hole concentration reduction and valence band convergence enhances thermopower of SnTe-AgI. • A maximum zT of ~1.05 was achieved at 860 K in p-type Sn{sub 0.95}Ag{sub 0.05}Te{sub 0.95}I{sub 0.05}.« less

Heterogeneous clinicopathological features of intraductal carcinoma of the prostate: a comparison between "precursor-like" and "regular type" lesions.

PubMed

Miyai, Kosuke; Divatia, Mukul K; Shen, Steven S; Miles, Brian J; Ayala, Alberto G; Ro, Jae Y

2014-01-01

Intraductal carcinoma of the prostate (IDC-P) has been described as a lesion associated with intraductal spread of invasive carcinoma and consequently aggressive disease. However, there are a few reported cases of pure IDC-P without an associated invasive component, strongly suggesting that this subset of IDC-P may represent a precursor lesion. We compared the clinicopathological features between the morphologically "regular type" IDC-P and "precursor-like" IDC-P. IDC-P was defined as follows; 1) solid/dense cribriform lesions or 2) loose cribriform/micropapillary lesions with prominent nuclear pleomorphism and/or non-focal comedonecrosis. We defined precursor-like IDC-P as follows; 1) IDC-P without adjoining invasive adenocarcinoma but carcinoma present distant from the IDC-P or 2) IDC-P having adjoining invasive microcarcinoma (less than 0.05 ml) and showing a morphologic transition from high-grade prostatic intraepithelial neoplasia (HGPIN) to the IDC-P. IDC-P lacking the features of precursor-like IDC-P was categorized as regular type IDC-P. Of 901 radical prostatectomies performed at our hospital, 141 and 14 showed regular type IDC-P and precursor-like IDC-P in whole-mounted specimens, respectively. Regular type IDC-P cases had significantly higher Gleason score, more frequent extraprostatic extension and seminal vesicle invasion, more advanced pathological T stage, and lower 5-year biochemical recurrence-free rate than precursor-like IDC-P cases. Multivariate analysis revealed nodal metastasis and the presence of regular type IDC-P as independent predictors for biochemical recurrence. Our data suggest that IDC-P may be heterogeneous with variable clinicopathological features. We also suggest that not all IDC-P cases represent intraductal spread of pre-existing invasive cancer, and a subset of IDC-P may be a precursor lesion.

Relationship between Small Animal Intern Rank and Performance at a University Teaching Hospital.

PubMed

Hofmeister, Erik H; Saba, Corey; Kent, Marc; Creevy, Kate E

2015-01-01

The purpose of this study was to determine if there is a relationship between selection committee rankings of internship applicants and the performance of small animal interns. The hypothesis was that there would be a relationship between selection committee rank order and intern performance; the more highly an application was ranked, the better the intern's performance scores would be. In 2007, the Department of Small Animal Medicine and Surgery instituted a standardized approach to its intern selection process both to streamline the process and to track its effectiveness. At the end of intern years 2010-2014, every faculty member in the department was provided an intern assessment form for that year's class. There was no relationship between an individual intern's final rank by the selection committee and his/her performance either as a percentile score or a Likert-type score (p=.25, R2=0.04; p=0.31, R2=0.03, respectively). Likewise, when interns were divided into the top and bottom quartile based on their final rank by the selection committee, there was no relationship between their rank and their performance as a percentile score (median rank 15 vs. 20; p=.14) or Likert-type score (median rank 14 vs. 19; p=.27). Institutions that use a similar intern selection method may need to reconsider the time and effort being expended for an outcome that does not predict performance. Alternatively, specific criteria more predictive of performance outcomes should be identified and employed in the internship selection process.

[Insulin-like growth factor-binding protein-1: a new biochemical marker of nonalcoholic fatty liver disease?].

PubMed

Graffigna, Mabel Nora; Belli, Susana H; de Larrañaga, Gabriela; Fainboim, Hugo; Estepo, Claudio; Peres, Silvia; García, Natalia; Levalle, Oscar

2009-03-01

to assess the presence of nonalcoholic fatty liver disease in patients with risk factors for this pathology (obesity, dyslipidemia, metabolic syndrome and diabetes type 2) and to determine the role of insulin, HOMA index, insulin-like growth factor-binding protein-1, sex hormone-binding globulin and plasminogen activator inhibitor type 1, as biochemical markers. Ninety-one patients with risk factors for nonalcoholic fatty liver disease were evaluated. Serum transaminases, insulin, sex hormone-binding globulin, insulin-like growth factor-binding protein-1 and plasminogen activator inhibitor type 1 were measured. The diagnosis of fatty liver was performed by ultrasonography and liver biopsies were performed to 31 subjects who had steatosis by ultrasonography and high alanine aminotransferase. Nonalcoholic fatty liver disease was present in 65 out of 91 patients (71,4%). Liver biopsy performed to 31 subjects confirmed nonalcoholic steatohepatitis. Twenty-five patients had different degrees of fibrosis. Those individuals with fatty liver had higher waist circumference, serum levels of triglycerides, insulin and HOMA index, and lower serum insulin-like growth factor-binding protein-1 concentration. The degree ofhepatic steatosis by ultrasonography was positively correlated to waist circumference, triglycerides, insulin and HOMA index (p<0,003; p<0,003; p<0,002 and p<0,001, respectively), and was negatively correlated to HDL-cholesterol and insulin-like growth factor-binding protein-1 (p<0,025 and p<0,018, respectively). We found a high prevalence of NAFLD in patients with risk factors, most of them overweight or obese. Although SHBG and PAI-1 have a closely relationship to insulin resistance, they did not show to be markers of NAFLD. Regardless of low IGFBP-1 levels associated with NAFLD, serum IGFBP-1 measure is less accessible than insulin and triglycerides levels, HOMA index and waist circumference. Moreover, it is not a better marker for NAFLD than the above mentioned.

Properties and characteristics of P(VDF/TrFE) transducers manufactured by a solution casting method for use in the MHz-range ultrasound in air.

PubMed

Takahashi, Sadayuki

2012-03-01

Highly effective piezoelectric polymer transducers operating in air at high frequencies have been successfully made by casting a solution of ferroelectric poly(vinylidene fluoride-co-trifluoroethylene) P(VDF/TrFE) directly on a backing metal plate, and their performance has been evaluated. By utilizing this method, it has been possible to develop the three kinds of transducers that operate respectively at 4, 6 and 10MHz in air. For precise evaluation of the performance of the P(VDF/TrFE) transducers, the absorption loss in air was measured up to 10MHz. It was confirmed that the empirical formula obtained from the measured absorption values in air at high frequencies was in alignment with its theoretical value. In addition, a high lateral resolution acoustic image of a ROM-Chip (amplitude-image) at 6MHz in air was successfully displayed using an air coupled concave type P(VDF/TrFE) transducer by bonding an epoxy adhesive. Copyright © 2011 Elsevier B.V. All rights reserved.

Physical effects of DCNQI derivatives doping as an N type organic semiconductor in organic photovoltaic cell performance.

PubMed

Lee, Joo Hyung; Oh, Se Young

2014-08-01

In the previous work, we have reported that organic photovoltaic (OPV) cells using DMDCNQI as an n-type second dopant material showed a high power conversion efficiency (PCE). In the present work, we have synthesized a novel DHDCNQI with long alkyl chains to improve the compatibility between the DHDCNQI dopant molecule and host P3HT polymer. We have fabricated OPV cells consisting of ITO/PEDOT:PSS/P3HT:PCBM:DHDCNQI/Al. We have investigated the characteristics of theses OPV cells using DCNQI derivative dopants from the measurements of the incident photon-to-current collection efficiency and photocurrent. The OPV cell using 3 wt% DHDCNQI exhibited a high PCE of 3.29% due to the high charge separation efficiency, good compatibility and low trap site effect.

Discriminatory Power and Reproducibility of Novel DNA Typing Methods for Mycobacterium tuberculosis Complex Strains

PubMed Central

Kremer, Kristin; Arnold, Catherine; Cataldi, Angel; Gutiérrez, M. Cristina; Haas, Walter H.; Panaiotov, Stefan; Skuce, Robin A.; Supply, Philip; van der Zanden, Adri G. M.; van Soolingen, Dick

2005-01-01

In recent years various novel DNA typing methods have been developed which are faster and easier to perform than the current internationally standardized IS6110 restriction fragment length polymorphism typing method. However, there has been no overview of the utility of these novel typing methods, and it is largely unknown how they compare to previously published methods. In this study, the discriminative power and reproducibility of nine recently described PCR-based typing methods for Mycobacterium tuberculosis were investigated using the strain collection of the interlaboratory study of Kremer et al. (J. Clin. Microbiol. 37:2607-2618, 1999). This strain collection contains 90 M. tuberculosis complex and 10 non-M. tuberculosis complex mycobacterial strains, as well as 31 duplicated DNA samples to assess reproducibility. The highest reproducibility was found with variable numbers of tandem repeat typing using mycobacterial interspersed repetitive units (MIRU VNTR) and fast ligation-mediated PCR (FLiP), followed by second-generation spoligotyping, ligation-mediated PCR (LM-PCR), VNTR typing using five repeat loci identified at the Queens University of Belfast (QUB VNTR), and the Amadio speciation PCR. Poor reproducibility was associated with fluorescent amplified fragment length polymorphism typing, which was performed in three different laboratories. The methods were ordered from highest discrimination to lowest by the Hunter-Gaston discriminative index as follows: QUB VNTR typing, MIRU VNTR typing, FLiP, LM-PCR, and spoligotyping. We conclude that both VNTR typing methods and FLiP typing are rapid, highly reliable, and discriminative epidemiological typing methods for M. tuberculosis and that VNTR typing is the epidemiological typing method of choice for the near future. PMID:16272496

Comparison of fresh-frozen cadaver and high-fidelity virtual reality simulator as methods of laparoscopic training.

PubMed

Sharma, Mitesh; Horgan, Alan

2012-08-01

The aim of this study was to compare fresh-frozen cadavers (FFC) with a high-fidelity virtual reality simulator (VRS) as training tools in minimal access surgery for complex and relatively simple procedures. A prospective comparative face validity study between FFC and VRS (LAP Mentor(™)) was performed. Surgeons were recruited to perform tasks on both FFC and VRS appropriately paired to their experience level. Group A (senior) performed a laparoscopic sigmoid colectomy, Group B (intermediate) performed a laparoscopic incisional hernia repair, and Group C (junior) performed basic laparoscopic tasks (BLT) (camera manipulation, hand-eye coordination, tissue dissection and hand-transferring skills). Each subject completed a 5-point Likert-type questionnaire rating the training modalities in nine domains. Data were analysed using nonparametric tests. Forty-five surgeons were recruited to participate (15 per skill group). Median scores for subjects in Group A were significantly higher for evaluation of FFC in all nine domains compared to VRS (p < 0.01). Group B scored FFC significantly better (p < 0.05) in all domains except task replication (p = 0.06). Group C scored FFC significantly better (p < 0.01) in eight domains but not on performance feedback (p = 0.09). When compared across groups, juniors accepted VRS as a training model more than did intermediate and senior groups on most domains (p < 0.01) except team work. Fresh-frozen cadaver is perceived as a significantly overall better model for laparoscopic training than the high-fidelity VRS by all training grades, irrespective of the complexity of the operative procedure performed. VRS is still useful when training junior trainees in BLT.

Effects of trap-assisted tunneling on gate-induced drain leakage in silicon-germanium channel p-type FET for scaled supply voltages

NASA Astrophysics Data System (ADS)

Tiwari, Vishal A.; Divakaruni, Rama; Hook, Terence B.; Nair, Deleep R.

2016-04-01

Silicon-germanium is considered as an alternative channel material to silicon p-type FET (pFET) for the development of energy efficient high performance transistors for 28 nm and beyond in a high-k metal gate technology because of its lower threshold voltage and higher mobility. However, gate-induced drain leakage (GIDL) is a concern for high threshold voltage device design because of tunneling at reduced bandgap. In this work, the trap-assisted tunneling and band-to-band tunneling (BTBT) effects on GIDL is analyzed and modeled for SiGe pFETs. Experimental results and Monte Carlo simulation results reveal that the pre-halo germanium pre-amorphization implant used to contain the short channel effects contribute to GIDL at the drain sidewall in addition to GIDL due to BTBT in SiGe devices. The results are validated by comparing the experimental observations with the numerical simulation and a set of calibrated models are used to describe the GIDL mechanisms for various drain and gate bias.

Anaerobic digestion of municipal solid wastes containing variable proportions of waste types.

PubMed

Akunna, J C; Abdullahi, Y A; Stewart, N A

2007-01-01

In many parts of the world there are significant seasonal variations in the production of the main organic wastes, food and green wastes. These waste types display significant differences in their biodegradation rates. This study investigated the options for ensuring process stability during the start up and operation of thermophilic high-solids anaerobic digestion of feedstock composed of varying proportions of food and green wastes. The results show that high seed sludge to feedstock ratio (or low waste loading rate) is necessary for ensuring process pH stability without chemical addition. It was also found that the proportion of green wastes in the feedstock can be used to regulate process pH, particularly when operating at high waste loading rates (or low seed sludge to feedstock ratios). The need for chemical pH correction during start-up and digestion operation decreased with increase in green wastes content of the feedstock. Food wastes were found to be more readily biodegradable leading to higher solids reduction while green wastes brought about pH stability and higher digestate solid content. Combining both waste types in various proportions brought about feedstock with varying buffering capacity and digestion performance. Thus, careful selection of feedstock composition can minimise the need for chemical pH regulation as well as reducing the cost for digestate dewatering for final disposal.

Cu/Cu2O nanocomposite films as a p-type modified layer for efficient perovskite solar cells.

PubMed

Chen, You-Jyun; Li, Ming-Hsien; Huang, Jung-Chun-Andrew; Chen, Peter

2018-05-16

Cu/Cu 2 O films grown by ion beam sputtering were used as p-type modified layers to improve the efficiency and stability of perovskite solar cells (PSCs) with an n-i-p heterojunction structure. The ratio of Cu to Cu 2 O in the films can be tuned by the oxygen flow ratio (O 2 /(O 2  + Ar)) during the sputtering of copper. Auger electron spectroscopy was performed to determine the elemental composition and chemical state of Cu in the films. Ultraviolet photoelectron spectroscopy and photoluminescence spectroscopy revealed that the valence band maximum of the p-type Cu/Cu 2 O matches well with the perovskite. The Cu/Cu 2 O film not only acts as a p-type modified layer but also plays the role of an electron blocking buffer layer. By introducing the p-type Cu/Cu 2 O films between the low-mobility hole transport material, spiro-OMeTAD, and the Ag electrode in the PSCs, the device durability and power conversion efficiency (PCE) were effectively improved as compared to the reference devices without the Cu/Cu 2 O interlayer. The enhanced PCE is mainly attributed to the high hole mobility of the p-type Cu/Cu 2 O film. Additionally, the Cu/Cu 2 O film serves as a protective layer against the penetration of humidity and Ag into the perovskite active layer.

Effect of Elliptical High Intensity Interval Training on Metabolic Risk Factor in Pre- and Type 2 Diabetes Patients: A Pilot Study.

PubMed

Fex, Annie; Leduc-Gaudet, Jean-Philippe; Filion, Marie-Eve; Karelis, Antony D; Aubertin-Leheudre, Mylène

2015-07-01

The purpose of the current study was to examine the impact of 12 weeks of elliptical high intensity interval training (HIIT) on metabolic risk factors and body composition in pre- and type 2 diabetes patients. Sixteen pre- (n = 8) and type 2 diabetes (n = 8) participants completed this study. Fasting blood glucose, HbA1c, anthropometric measurements, body composition (DXA), blood pressure, resting heart rate, VO2max, and dietary factors, as well as total and physical activity energy expenditure, were measured. The HIIT program on the elliptical was performed 3 times a week for 12 weeks. After the intervention, we observed a significant improvement for fasting blood glucose, waist and hip circumference, appendicular fat mass, leg lean body mass and appendicular lean body mass, systolic blood pressure, resting heart rate, and VO2max (P < .05). In addition, we noted a lower tendency for leg fat mass (P = .06) and diastolic blood pressure (P = .05) as well as a higher tendency for total energy expenditure (P = .06) after the intervention. The current study indicates that elliptical HIIT seems to improve metabolic risk factors and body composition in pre- and type 2 diabetes patients.

Effects of a regular exercise program on biochemical parameters of type 2 diabetes mellitus patients.

PubMed

Dinçer, Şensu; Altan, Mehmet; Terzioğlu, Duygu; Uslu, Ezel; Karşidağ, Kubilay; Batu, Şule; Metin, Gökhan

2016-11-01

We aimed to investigate the effects of a regular exercise program on exercise capacity, blood biochemical profiles, certain antioxidant and oxidative stress parameters of type 2 Diabetes mellitus (DM) patients. Thirty one type 2 DM patients (ages ranging from 42-65 years) who have hemoglobin A1c (HbA1c) levels ≥7.5% and ≤9.5% were included to study and performed two cardiopulmonary exercise tests (CPET) before and after the exercise program. Subjects performed aerobic exercise training for 90 minutes a day; 3 days a week during 12 weeks. Blood samples were collected to analyze certain oxidant and antioxidant parameters (advanced oxidation protein products [AOPP], ferric reducing ability of plasma [FRAP], malondialdehyde [MDA], and sialic acid [SA]), blood lipid profile, fasting blood glucose (FBG) and HbA1c. At the end of the program HbA1c and FBG, triglyceride (TG) and very-low-density lipoprotein (VLDL) levels decreased and high-density lipoprotein (HDL) increased significantly (P=0.000, P=0.001, P=0.008, P=0,001 and P=0.02, respectively). AOPP, FRAP, SA levels of the patients increased significantly following first CPET (P=0.000, P=0.049, P=0.014 respectively). At the end of the exercise program AOPP level increased significantly following last CPET. Baseline SA level increased significantly following exercise program (P=0.002). We suggest that poor glycemic control which plays the major role in the pathogenesis of DM and its complications would be improved by 12 weeks of a regular exercise program. Whereas the acute exercise induces protein oxidation, regularly aerobic training may enhance the antioxidant status of type 2 DM patients.

The Effect of Plan Type and Comprehensive Medication Reviews on High-Risk Medication Use.

PubMed

Almodovar, Armando Silva; Axon, David Rhys; Coleman, Ashley M; Warholak, Terri; Nahata, Milap C

2018-05-01

In 2007, the Centers for Medicare & Medicaid Services (CMS) instituted a star rating system using performance outcome measures to assess Medicare Advantage Prescription Drug (MAPD) and Prescription Drug Plan (PDP) providers. To assess the relationship between 2 performance outcome measures for Medicare insurance providers, comprehensive medication reviews (CMRs), and high-risk medication use. This cross-sectional study included Medicare Part C and Part D performance data from the 2014 and 2015 calendar years. Performance data were downloaded per Medicare contract from the CMS. We matched Medicare insurance provider performance data with the enrollment data of each contract. Mann Whitney U and Spearman rho tests and a hierarchical linear regression model assessed the relationship between provider characteristics, high-risk medication use, and CMR completion rate outcome measures. In 2014, an inverse correlation between CMR completion rate and high-risk medication use was identified among MAPD plan providers. This relationship was further strengthened in 2015. No correlation was detected between the CMR completion rate and high-risk medication use among PDP plan providers in either year. A multivariate regression found an inverse association with high-risk medication use among MAPD plan providers in comparison with PDP plan providers in 2014 (beta = -0.358, P < 0.001) and 2015 (beta = -0.350, P < 0.001), the CMR completion rate in 2015 (beta = -0.221, P < 0.001), and enrollee population size in 2015 (beta = -0.203, P = 0.001). This study found that MAPD plan providers and higher CMR completion rates were associated with lower use of high-risk medications among beneficiaries. No outside funding supported this study. Silva Almodovar reports a fellowship funded by SinfoniaRx, Tucson, Arizona, during the time of this study. The other authors have nothing to disclose.

[Evaluation of Wondfo Rapid Diagnostic Kit for detecting Plasmodium ovale and analysis of influencing factors].

PubMed

Feng, Tang; Jian-Xia, Tang; Feng, Lu; Sui, Xu; Ya-Ping, Gu; De-Sheng, Tong; Guo-Ding, Zhu; Hai-Yong, Hua; Hua-Yun, Zhou; Jun, Cao

2016-03-21

To evaluate the Wondfo Rapid Diagnostic Kit (Pf-LDH/Pan -pLDH) for detecting Plasmodium ovale and analyze the influence of parasitaemia, concentration and polymorphism of pLDH on the performances. A total of 100 blood samples from P. ovale patients confirmed by PCR were detected with the Wondfo Rapid Diagnostic Kit according to the manufacturers'instructions. The parasitaemia was determined by the microscopic examination. The concentration of pLDH was measured by ELISA tests. The LDH gene of P. ovale was amplified by PCR and sequenced. The influence of these three factors on the positive rate was analyzed. The overall positive rate of Wondfo Rapid Diagnostic Kit was 70.0% (70/100). The positive rate was 27.3% for the samples with parasitaemia ≤ 500 parasites/μl and reached 75.0%-75.4% when parasitaemia > 500 parasites/μl. The positive rate was 6.7% for samples with a low pLDH concentration ( A values ≤ 0.100) and reached 95.1%-100% at a high pLDH concentration ( A values > 0.100). The results of sequence analysis indicated that all the samples could be divided into 2 types, P. o. curtisi and P. o. wallikeri . The gene homology of LDH between 2 types was 97%. There were 24 single nucleotide polymorphism (s) (SNPs) between 2 types, while only 3 SNPs were non-synonymous mutations. The homology of LDH amino acid sequences between 2 types was 99%; only 3 amino acids were different. The positive rates for P. o. curtisi and P. o. wallikeri were 73.1% (38/52) and 66.7% (32/48) respectively; there was no statistically significant difference ( P > 0.05). The Wondfo Rapid Diagnostic Kit (Pf-LDH/Pan-pLDH) performs better than most of the similar products for the detection of P. ovale , and the positive rates are closely related to the parasitaemia and concentration of pLDH, while no related to the polymorphism of pLDH gene.

Demographic and Practice Characteristics of Pathologists Who Enjoy Breast Tissue Interpretation

PubMed Central

Oster, Natalia V.; Geller, Berta; Carney, Patricia A.; Reisch, Lisa M.; Onega, Tracy; Weaver, Donald L.; Frederick, Paul; Elmore, Joann G.

2015-01-01

Summary Physician attributes, job satisfaction and confidence in clinical skills are associated with enhanced performance and better patient outcomes. We surveyed 252 pathologists to evaluate associations between enjoyment of breast pathology, demographic/clinical characteristics and diagnostic performance. Diagnostic performance was determined by agreement with patient cases previously reviewed by a panel of experienced pathologists. Eighty-three percent of study participants reported enjoying breast pathology. Pathologists who enjoy breast interpretation were more likely to review ≥10 cases/week (p=0.003), report breast interpretation expertise (p=0.013), and high levels of confidence interpreting breast pathology (p<0.001). These pathologists were less likely to report that the field was challenging (p<0.001) and that breast cases make them more nervous than other types of pathology (p<0.001). Enjoyment was not associated with diagnostic performance. Millions of women undergo breast biopsy annually, thus it is reassuring that although nearly a fifth of practicing pathologists who interpret breast tissue report not enjoying the field, precision is not impacted. PMID:25554017

Threshold voltage tuning in AlGaN/GaN HFETs with p-type Cu2O gate synthesized by magnetron reactive sputtering

NASA Astrophysics Data System (ADS)

Wang, Lei; Li, Liuan; Xie, Tian; Wang, Xinzhi; Liu, Xinke; Ao, Jin-Ping

2018-04-01

In present study, copper oxide films were prepared at different sputtering powers (10-100 W) using magnetron reactive sputtering. The crystalline structure, surface morphologies, composition, and optical band gap of the as-grown films are dependent on sputtering power. As the sputtering power decreasing from 100 to 10 W, the composition of films changed from CuO to quasi Cu2O domination. Moreover, when the sputtering power is 10 W, a relative high hole carrier density and high-surface-quality quasi Cu2O thin film can be achieved. AlGaN/GaN HFETs were fabricated with the optimized p-type quasi Cu2O film as gate electrode, the threshold voltage of the device shows a 0.55 V positive shift, meanwhile, a lower gate leakage current, a higher ON/OFF drain current ratio of ∼108, a higher electron mobility (1465 cm2/Vs), and a lower subthreshold slope of 74 mV/dec are also achieved, compared with the typical Ni/Au-gated HFETs. Therefore, Cu2O have a great potential to develop high performance p-type gate AlGaN/GaN HFETs.

Low temperature thermoelectric properties of p-type doped single-crystalline SnSe

NASA Astrophysics Data System (ADS)

Wang, Si; Hui, Si; Peng, Kunling; Bailey, Trevor P.; Liu, Wei; Yan, Yonggao; Zhou, Xiaoyuan; Tang, Xinfeng; Uher, Ctirad

2018-04-01

SnSe single crystals have been widely studied lately as a result of their record high ZT and controversial low thermal conductivity. Much research has focused on the high-temperature properties of single crystals and polycrystalline SnSe, but few studies were carried out on the low-temperature properties of doped single-crystalline SnSe. To study the mechanism of the charge carrier and phonon scattering, and to eliminate the ambiguity of the high temperature thermal conductivity measurement, we performed low temperature transport characterization of Na-doped and Ag-doped single-crystalline SnSe by a longitudinal steady-state technique. The electronic transport property measurements suggest that Na is a more efficient p-type dopant in SnSe than Ag. In the thermal conductivity data, we observe pronounced dielectric peak around 10 K with magnitude dependent on the doping level. In the p-type doped samples, we found that our room temperature lattice thermal conductivities (>1.74 W m-1 K-1) are in general higher than those previously reported. Based on these findings, our study implies that the lattice thermal conductivity values of doped and pure single-crystalline SnSe were underestimated.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Ao; Liu, Guoxia, E-mail: gxliu@qdu.edu.cn, E-mail: fukaishan@yahoo.com; Zhu, Huihui

Solution-processed p-type oxide semiconductors have recently attracted increasing interests for the applications in low-cost optoelectronic devices and low-power consumption complementary metal-oxide-semiconductor circuits. In this work, p-type nickel oxide (NiO{sub x}) thin films were prepared using low-temperature solution process and integrated as the channel layer in thin-film transistors (TFTs). The electrical properties of NiO{sub x} TFTs, together with the characteristics of NiO{sub x} thin films, were systematically investigated as a function of annealing temperature. By introducing aqueous high-k aluminum oxide (Al{sub 2}O{sub 3}) gate dielectric, the electrical performance of NiO{sub x} TFT was improved significantly compared with those based on SiO{submore » 2} dielectric. Particularly, the hole mobility was found to be 60 times enhancement, quantitatively from 0.07 to 4.4 cm{sup 2}/V s, which is mainly beneficial from the high areal capacitance of the Al{sub 2}O{sub 3} dielectric and high-quality NiO{sub x}/Al{sub 2}O{sub 3} interface. This simple solution-based method for producing p-type oxide TFTs is promising for next-generation oxide-based electronic applications.« less

Analysis on the time and frequency domains of the acceleration in front crawl stroke.

PubMed

Gil, Joaquín Madera; Moreno, Luis-Millán González; Mahiques, Juan Benavent; Muñoz, Víctor Tella

2012-05-01

The swimming involves accelerations and decelerations in the swimmer's body. Thus, the main objective of this study is to make a temporal and frequency analysis of the acceleration in front crawl swimming, regarding the gender and the performance. The sample was composed by 31 male swimmers (15 of high-level and 16 of low-level) and 20 female swimmers (11 of high-level and 9 of low-level). The acceleration was registered from the third complete cycle during eight seconds in a 25 meters maximum velocity test. A position transducer (200Hz) was used to collect the data, and it was synchronized to an aquatic camera (25Hz). The acceleration in the temporal (root mean square, minimum and maximum of the acceleration) and frequency (power peak, power peak frequency and spectral area) domains was calculated with Fourier analysis, as well as the velocity and the spectrums distribution in function to present one or more main peaks (type 1 and type 2). A one-way ANOVA was used to establish differences between gender and performance. Results show differences between genders in all the temporal domain variables (p<0.05) and only the Spectral Area (SA) in the frequency domain (p<0.05). Between gender and performance, only the Root Mean Square (RMS) showed differences in the performance of the male swimmers (p<0.05) and in the higher level swimmers, the Maximum (Max) and the Power Peak (PP) of the acceleration showed differences between both genders (p<0.05). These results confirms the importance of knowing the RMS to determine the efficiency of the swimmers regarding gender and performance level.

Electrostatically tunable lateral MoTe2 p-n junction for use in high-performance optoelectronics.

PubMed

Wang, Zhenxing; Wang, Feng; Yin, Lei; Huang, Yun; Xu, Kai; Wang, Fengmei; Zhan, Xueying; He, Jun

2016-07-21

Because of their ultimate thickness, layered structure and high flexibility, pn junctions based on layered two-dimensional semiconductors have been attracting increasing attention recently. In this study, for the first time, we fabricated lateral pn junctions (LPNJs) based on ultrathin MoTe2 by introducing two separated electrostatic back gates, and investigated their electronic and photovoltaic performance. Pn, np, nn, and pp junctions can be easily realized by modulating the conductive channel type using gate voltages with different polarities. Strong rectification effects were observed in the pn and np junctions and the rectification ratio reached ∼5 × 10(4). Importantly, we find a unique phenomenon that the parameters for MoTe2 LPNJs experience abrupt changes during the transition from p to n or n to p. Furthermore, a high performance photovoltaic device with a filling factor of above 51% and electrical conversion efficiency (η) of around 0.5% is achieved. Our findings are of importance to comprehensively understand the electronic and optoelectronic properties of MoTe2 and may further open up novel electronic and optoelectronic device applications.

Enhanced Photoelectrocatalytic Activity of BiOI Nanoplate-Zinc Oxide Nanorod p-n Heterojunction.

PubMed

Kuang, Pan-Yong; Ran, Jing-Run; Liu, Zhao-Qing; Wang, Hong-Juan; Li, Nan; Su, Yu-Zhi; Jin, Yong-Gang; Qiao, Shi-Zhang

2015-10-19

The development of highly efficient and robust photocatalysts has attracted great attention for solving the global energy crisis and environmental problems. Herein, we describe the synthesis of a p-n heterostructured photocatalyst, consisting of ZnO nanorod arrays (NRAs) decorated with BiOI nanoplates (NPs), by a facile solvothermal method. The product thus obtained shows high photoelectrochemical water splitting performance and enhanced photoelectrocatalytic activity for pollutant degradation under visible light irradiation. The p-type BiOI NPs, with a narrow band gap, not only act as a sensitizer to absorb visible light and promote electron transfer to the n-type ZnO NRAs, but also increase the contact area with organic pollutants. Meanwhile, ZnO NRAs provide a fast electron-transfer channel, thus resulting in efficient separation of photoinduced electron-hole pairs. Such a p-n heterojunction nanocomposite could serve as a novel and promising catalyst in energy and environmental applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High efficiency photovoltaic device

DOEpatents

Guha, Subhendu; Yang, Chi C.; Xu, Xi Xiang

1999-11-02

An N-I-P type photovoltaic device includes a multi-layered body of N-doped semiconductor material which has an amorphous, N doped layer in contact with the amorphous body of intrinsic semiconductor material, and a microcrystalline, N doped layer overlying the amorphous, N doped material. A tandem device comprising stacked N-I-P cells may further include a second amorphous, N doped layer interposed between the microcrystalline, N doped layer and a microcrystalline P doped layer. Photovoltaic devices thus configured manifest improved performance, particularly when configured as tandem devices.

Comparison of the BCI Performance between the Semitransparent Face Pattern and the Traditional Face Pattern.

PubMed

Cheng, Jiao; Jin, Jing; Wang, Xingyu

2017-01-01

Brain-computer interface (BCI) systems allow users to communicate with the external world by recognizing the brain activity without the assistance of the peripheral motor nervous system. P300-based BCI is one of the most common used BCI systems that can obtain high classification accuracy and information transfer rate (ITR). Face stimuli can result in large event-related potentials and improve the performance of P300-based BCI. However, previous studies on face stimuli focused mainly on the effect of various face types (i.e., face expression, face familiarity, and multifaces) on the BCI performance. Studies on the influence of face transparency differences are scarce. Therefore, we investigated the effect of semitransparent face pattern (STF-P) (the subject could see the target character when the stimuli were flashed) and traditional face pattern (F-P) (the subject could not see the target character when the stimuli were flashed) on the BCI performance from the transparency perspective. Results showed that STF-P obtained significantly higher classification accuracy and ITR than those of F-P ( p < 0.05).

A High-Performance Sodium-Ion Full Cell with a Layered Oxide Cathode and a Phosphorous-Based Composite Anode

DOE PAGES

Oh, Seung-Min; Oh, Pilgun; Kim, Sang-Ok; ...

2016-12-29

A low-cost sodium-ion full cell with a O3-type layered Na[Cu 0.2(Fe 1/3Mn2/3) 0.8]O 2 cathode and an alloy-type P-TiP2-C anode is presented. The cathode is synthesized by an oxalate coprecipitation method and optimized cathodes shows a high specific capacity of 135 mAh g -1 at 0.1C rate with a high rate capability of 90 mAh g-1 at 1C rate and 70 mAh g -1 at 2C rate with good cyclability. The full cell exhibits better capacity retention than the half cell with the cathode due to the elimination of the degradation caused by sodium-metal anode. The dramatically enhanced electrochemical performancemore » of the Na[Cu 0.2(Fe 1/3Mn 2/3) 0.8]O 2 / P-TiP 2-C full cell compared to that of the sample with no Cu is attributed to the structural stabilization imparted by Cu by suppressing the phase change from the O3 structure to the P3 structure during cycling.« less

High-efficiency indium tin oxide/indium phosphide solar cells

NASA Technical Reports Server (NTRS)

Li, X.; Wanlass, M. W.; Gessert, T. A.; Emery, K. A.; Coutts, T. J.

1989-01-01

Improvements in the performance of indium tin oxide (ITO)/indium phosphide solar cells have been realized by the dc magnetron sputter deposition of n-ITO onto an epitaxial p/p(+) structure grown on commercial p(+) bulk substrates. The highest efficiency cells were achieved when the surface of the epilayer was exposed to an Ar/H2 plasma before depositing the bulk of the ITO in a more typical Ar/O2 plasma. With H2 processing, global efficiencies of 18.9 percent were achieved. It is suggested that the excellent performance of these solar cells results from the optimization of the doping, thickness, transport, and surface properties of the p-type base, as well as from better control over the ITO deposition procedure.

Controlled n-Type Doping of Carbon Nanotube Transistors by an Organorhodium Dimer.

PubMed

Geier, Michael L; Moudgil, Karttikay; Barlow, Stephen; Marder, Seth R; Hersam, Mark C

2016-07-13

Single-walled carbon nanotube (SWCNT) transistors are among the most developed nanoelectronic devices for high-performance computing applications. While p-type SWCNT transistors are easily achieved through adventitious adsorption of atmospheric oxygen, n-type SWCNT transistors require extrinsic doping schemes. Existing n-type doping strategies for SWCNT transistors suffer from one or more issues including environmental instability, limited carrier concentration modulation, undesirable threshold voltage control, and/or poor morphology. In particular, commonly employed benzyl viologen n-type doping layers possess large thicknesses, which preclude top-gate transistor designs that underlie high-density integrated circuit layouts. To overcome these limitations, we report here the controlled n-type doping of SWCNT thin-film transistors with a solution-processed pentamethylrhodocene dimer. The charge transport properties of organorhodium-treated SWCNT thin films show consistent n-type behavior when characterized in both Hall effect and thin-film transistor geometries. Due to the molecular-scale thickness of the organorhodium adlayer, large-area arrays of top-gated, n-type SWCNT transistors are fabricated with high yield. This work will thus facilitate ongoing efforts to realize high-density SWCNT integrated circuits.

Nonepitaxial Thin-Film InP for Scalable and Efficient Photocathodes.

PubMed

Hettick, Mark; Zheng, Maxwell; Lin, Yongjing; Sutter-Fella, Carolin M; Ager, Joel W; Javey, Ali

2015-06-18

To date, some of the highest performance photocathodes of a photoelectrochemical (PEC) cell have been shown with single-crystalline p-type InP wafers, exhibiting half-cell solar-to-hydrogen conversion efficiencies of over 14%. However, the high cost of single-crystalline InP wafers may present a challenge for future large-scale industrial deployment. Analogous to solar cells, a thin-film approach could address the cost challenges by utilizing the benefits of the InP material while decreasing the use of expensive materials and processes. Here, we demonstrate this approach, using the newly developed thin-film vapor-liquid-solid (TF-VLS) nonepitaxial growth method combined with an atomic-layer deposition protection process to create thin-film InP photocathodes with large grain size and high performance, in the first reported solar device configuration generated by materials grown with this technique. Current-voltage measurements show a photocurrent (29.4 mA/cm(2)) and onset potential (630 mV) approaching single-crystalline wafers and an overall power conversion efficiency of 11.6%, making TF-VLS InP a promising photocathode for scalable and efficient solar hydrogen generation.

The relationship between event-related potentials, stress perception and personality type in patients with multiple sclerosis without cognitive impairment: A pilot study.

PubMed

Waliszewska-Prosół, Marta; Nowakowska-Kotas, Marta; Kotas, Roman; Bańkowski, Tomasz; Pokryszko-Dragan, Anna; Podemski, Ryszard

2018-06-08

The clinical course of multiple sclerosis (MS) can vary significantly among patients and is affected by exogenous and endogenous factors. Among these, stress and personality type have been gaining more attention. The aim of this study was to investigate the parameters of event-related potentials (ERPs) with regards to stress perception and personality type, as well as cognitive performance in MS patients. The study group consisted of 30 MS patients and 26 healthy controls. Auditory ERPs were performed in both groups, including an analysis of P300 and N200 response parameters. The Perceived Stress Scale (PSS) was used in the MS group to measure the perception of stress. The D-type Scale (DS14) scale was used to determine the features of Type D personality, characterized by social inhibition and negative affectivity. The score on the PSS corresponded with a moderate or high level of stress perception in 63% of MS patients, while 23% of patients presented with a Type D personality. P300 latencies were significantly longer (p = 0.001), N200 amplitudes were significantly higher (p = 0.004), and N200 latencies were longer in MS patients than in the controls. Strong positive correlations were found between N200 and P300 amplitudes, as well as between the DS14 and PSS results. Most MS patients experience moderate to severe stress. ERP abnormalities were found in MS patients who did not have overt cognitive impairment and showed correlations with stress levels and negative affectivity. Event-related potentials may be useful in assessing the influence of stress and emotions on the course of MS.

Heritability, parental transmission and environment correlation of pediatric-onset type 2 diabetes mellitus and metabolic syndrome-related traits.

PubMed

Miranda-Lora, América L; Vilchis-Gil, Jenny; Molina-Díaz, Mario; Flores-Huerta, Samuel; Klünder-Klünder, Miguel

2017-04-01

To estimate the heritability, parental transmission and environmental contributions to the phenotypic variation in type 2 diabetes mellitus and metabolic syndrome-related traits in families of Mexican children and adolescents. We performed a cross-sectional study of 184 tri-generational pedigrees with a total of 1160 individuals (99 families with a type 2 diabetes mellitus proband before age 19). The family history of type 2 diabetes mellitus in three generations was obtained by interview. Demographic, anthropometric, biochemical and lifestyle information was corroborated in parents and offspring. We obtained correlations for metabolic traits between relative pairs, and variance component methods were used to determine the heritability and environmental components. The heritability of early-onset of type 2 diabetes mellitus was 0.50 (p<1.0e-7). The heritability was greater than 0.5 for hypertension, hypoalphalipoproteinemia, hypercholesterolemia, body mass index, waist circumference, blood pressure, 2-h insulin, and cholesterol (p<0.001). In contrast, we observed a high environmental correlation (>0.50) for blood pressure, HbA1c and HDL-cholesterol after multivariate adjustment (p<0.05). Several traits, such as type 2 diabetes mellitus and insulin resistance, were significantly correlated only through the mother and others, such as hypertriglyceridemia, were significantly correlated only through the father. This study demonstrates that type 2 diabetes mellitus and metabolic syndrome-related traits are highly heritable among Mexican children and adolescents. Furthermore, several cardiometabolic factors have strong heritability and/or high environmental contributions that highlight the complex architecture of these alterations. Copyright © 2017 Elsevier B.V. All rights reserved.

PIK3CA missense mutation is associated with unfavorable outcome in grade 3 endometrioid carcinoma but not in serous endometrial carcinoma.

PubMed

McIntyre, John B; Nelson, Gregg S; Ghatage, Prafull; Morris, Don; Duggan, Máire A; Lee, Cheng-Han; Doll, Corinne M; Köbel, Martin

2014-01-01

To evaluate the outcome association of PIK3CA mutational status within histological types of rigorously classified high-grade endometrial carcinomas. We assessed PIK3CA mutational status in exon 9 and exon 20 hot spots by Sanger sequencing of DNA derived from formalin fixed paraffin embedded tissue of 57 grade 3 endometrioid, 26 serous, 11 clear cell and 5 dedifferentiated carcinomas. We correlated PIK3CA mutation status with clinicopathological and other molecular parameters. Univariate and multivariate disease specific survival analysis was performed using Kaplan-Meier and Cox regression analyses. PIK3CA exon 9 or exon 20 missense mutations were identified in 20 of 99 (20%) high-grade endometrial carcinomas without significant difference across histological types (p=0.22). Presence of PIK3CA exon 9 or exon 20 missense mutations was associated with shorter disease specific survival within grade 3 endometrioid (p=0.0029) but not endometrial serous (p=0.57) carcinoma based on univariate analysis. Within grade 3 endometrioid carcinoma, PIK3CA exon 9 or exon 20 missense mutations were more commonly observed in cases that were deficient for mismatch repair protein expression (p=0.0058) and showed loss of ARID1A expression (p=0.037). PIK3CA exon 9 or exon 20 missense mutations are present across all histological types of high-grade endometrial carcinomas but a significant outcome association is only seen in grade 3 endometrioid carcinoma, suggesting a greater biological importance in this tumor type. Copyright © 2013 Elsevier Inc. All rights reserved.

Depression and Associated Factors in Patients with Type 2 Diabetes Mellitus.

PubMed

Hashim, N A; Ariaratnam, S; Salleh, M R; Said, M A; Sulaiman, A H

2016-06-01

To determine the prevalence of major depressive disorder and its association with socio-demographic and clinical factors in patients with type 2 diabetes mellitus. This was a cross-sectional study of patients with type 2 diabetes mellitus who attended the hospital-based primary care clinics at the University Malaya Medical Centre, Kuala Lumpur, Malaysia. The patients were interviewed using the Mini-International Neuropsychiatric Interview to diagnose depression based on the DSM-IV criteria. The socio-demographic and clinical data were obtained by interviewing the patients and subsequently verified against their respective case notes. A total of 204 patients were recruited. The prevalence of major depressive disorder was 15.7%. Major depressive disorder was significantly associated with younger age of patients (mean ± standard deviation, 57.8 ± 15.1 years, p = 0.04), younger age at diagnosis of diabetes mellitus (46.2 ± 13.0 years, p = 0.01), having secondary education (p = 0.02), and having a history of depression (p = 0.002). Multivariate analysis showed that current age (p = 0.04), duration of diabetes mellitus (p = 0.04), age at diagnosis of diabetes mellitus (p = 0.01), and secondary education (p = 0.01) were significant factors. The prevalence of major depressive disorder was high among patients with type 2 diabetes mellitus. Screening of patients with type 2 diabetes mellitus for depression should be performed periodically or routinely, especially in the primary care setting.

Polycrystalline ZrTe 5 Parametrized as a Narrow-Band-Gap Semiconductor for Thermoelectric Performance

DOE PAGES

Miller, Samuel A.; Witting, Ian; Aydemir, Umut; ...

2018-01-24

The transition-metal pentatellurides HfTe 5 and ZrTe 5 have been studied for their exotic transport properties with much debate over the transport mechanism, band gap, and cause of the resistivity behavior, including a large low-temperature resistivity peak. Single crystals grown by the chemical-vapor-transport method have shown an n-p transition of the Seebeck coefficient at the same temperature as a peak in the resistivity. We show that behavior similar to that of single crystals can be observed in iodine-doped polycrystalline samples but that undoped polycrystalline samples exhibit drastically different properties: they are p type over the entire temperature range. Additionally, themore » thermal conductivity for polycrystalline samples is much lower, 1.5 Wm -1 K -1, than previously reported for single crystals. It is found that the polycrystalline ZrTe 5 system can be modeled as a simple semiconductor with conduction and valence bands both contributing to transport, separated by a band gap of 20 meV. This model demonstrates to first order that a simple two-band model can explain the transition from n- to p-type behavior and the cause of the anomalous resistivity peak. Combined with the experimental data, the two-band model shows that carrier concentration variation is responsible for differences in behavior between samples. Using the two-band model, the thermoelectric performance at different doping levels is predicted, finding zT=0.2 and 0.1 for p and n type, respectively, at 300 K, and zT=0.23 and 0.32 for p and n type at 600 K. Given the reasonably high zT that is comparable in magnitude for both n and p type, a thermoelectric device with a single compound used for both legs is feasible.« less

Polycrystalline ZrTe5 Parametrized as a Narrow-Band-Gap Semiconductor for Thermoelectric Performance

NASA Astrophysics Data System (ADS)

Miller, Samuel A.; Witting, Ian; Aydemir, Umut; Peng, Lintao; Rettie, Alexander J. E.; Gorai, Prashun; Chung, Duck Young; Kanatzidis, Mercouri G.; Grayson, Matthew; Stevanović, Vladan; Toberer, Eric S.; Snyder, G. Jeffrey

2018-01-01

The transition-metal pentatellurides HfTe5 and ZrTe5 have been studied for their exotic transport properties with much debate over the transport mechanism, band gap, and cause of the resistivity behavior, including a large low-temperature resistivity peak. Single crystals grown by the chemical-vapor-transport method have shown an n -p transition of the Seebeck coefficient at the same temperature as a peak in the resistivity. We show that behavior similar to that of single crystals can be observed in iodine-doped polycrystalline samples but that undoped polycrystalline samples exhibit drastically different properties: they are p type over the entire temperature range. Additionally, the thermal conductivity for polycrystalline samples is much lower, 1.5 Wm-1 K-1 , than previously reported for single crystals. It is found that the polycrystalline ZrTe5 system can be modeled as a simple semiconductor with conduction and valence bands both contributing to transport, separated by a band gap of 20 meV. This model demonstrates to first order that a simple two-band model can explain the transition from n - to p -type behavior and the cause of the anomalous resistivity peak. Combined with the experimental data, the two-band model shows that carrier concentration variation is responsible for differences in behavior between samples. Using the two-band model, the thermoelectric performance at different doping levels is predicted, finding z T =0.2 and 0.1 for p and n type, respectively, at 300 K, and z T =0.23 and 0.32 for p and n type at 600 K. Given the reasonably high z T that is comparable in magnitude for both n and p type, a thermoelectric device with a single compound used for both legs is feasible.

Polycrystalline ZrTe{sub 5} Parameterized as a Narrow Band Gap Semiconductor for Thermoelectric Performance.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, Samuel A.; Witting, Ian; Aydemir, Umut

The transition-metal pentatellurides HfTe5 and ZrTe5 have been studied for their exotic transport properties with much debate over the transport mechanism, band gap, and cause of the resistivity behavior, including a large low-temperature resistivity peak. Single crystals grown by the chemical-vapor-transport method have shown an n-p transition of the Seebeck coefficient at the same temperature as a peak in the resistivity. We show that behavior similar to that of single crystals can be observed in iodine-doped polycrystalline samples but that undoped polycrystalline samples exhibit drastically different properties: they are p type over the entire temperature range. Additionally, the thermal conductivitymore » for polycrystalline samples is much lower, 1.5 Wm -1 K -1, than previously reported for single crystals. It is found that the polycrystalline ZrTe 5 system can be modeled as a simple semiconductor with conduction and valence bands both contributing to transport, separated by a band gap of 20 meV. This model demonstrates to first order that a simple two-band model can explain the transition from n- to p-type behavior and the cause of the anomalous resistivity peak. Combined with the experimental data, the two-band model shows that carrier concentration variation is responsible for differences in behavior between samples. Using the twoband model, the thermoelectric performance at different doping levels is predicted, finding zT =0.2 and 0.1 for p and n type, respectively, at 300 K, and zT= 0.23 and 0.32 for p and n type at 600 K. Given the reasonably high zT that is comparable in magnitude for both n and p type, a thermoelectric device with a single compound used for both legs is feasible.« less

Polycrystalline ZrTe 5 Parametrized as a Narrow-Band-Gap Semiconductor for Thermoelectric Performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, Samuel A.; Witting, Ian; Aydemir, Umut

The transition-metal pentatellurides HfTe 5 and ZrTe 5 have been studied for their exotic transport properties with much debate over the transport mechanism, band gap, and cause of the resistivity behavior, including a large low-temperature resistivity peak. Single crystals grown by the chemical-vapor-transport method have shown an n-p transition of the Seebeck coefficient at the same temperature as a peak in the resistivity. We show that behavior similar to that of single crystals can be observed in iodine-doped polycrystalline samples but that undoped polycrystalline samples exhibit drastically different properties: they are p type over the entire temperature range. Additionally, themore » thermal conductivity for polycrystalline samples is much lower, 1.5 Wm -1 K -1, than previously reported for single crystals. It is found that the polycrystalline ZrTe 5 system can be modeled as a simple semiconductor with conduction and valence bands both contributing to transport, separated by a band gap of 20 meV. This model demonstrates to first order that a simple two-band model can explain the transition from n- to p-type behavior and the cause of the anomalous resistivity peak. Combined with the experimental data, the two-band model shows that carrier concentration variation is responsible for differences in behavior between samples. Using the two-band model, the thermoelectric performance at different doping levels is predicted, finding zT=0.2 and 0.1 for p and n type, respectively, at 300 K, and zT=0.23 and 0.32 for p and n type at 600 K. Given the reasonably high zT that is comparable in magnitude for both n and p type, a thermoelectric device with a single compound used for both legs is feasible.« less

The rise in metastasectomy across cancer types over the past decade.

PubMed

Bartlett, Edmund K; Simmons, Kristina D; Wachtel, Heather; Roses, Robert E; Fraker, Douglas L; Kelz, Rachel R; Karakousis, Giorgos C

2015-03-01

Although studies of metastasectomy have been limited primarily to institutional experiences, reports of favorable long-term outcomes have generated increasing interest. In the current study, the authors attempted to define the national practice patterns in metastasectomy for 4 common malignancies with varying responsiveness to systemic therapy. The National (Nationwide) Inpatient Sample was used to estimate the national incidence of metastasectomy for colorectal cancer, lung cancer, breast cancer, and melanoma from 2000 through 2011. Incidence-adjusted rates were determined for liver, lung, brain, small bowel, and adrenal metastasectomies. The average annual percentage change (AAPC) in metastasectomy by cancer type was calculated using joinpoint regression. Colorectal cancer was the most common indication for metastasectomy (87,407 cases; 95% confidence interval [95% CI], 86,307-88,507 cases) followed by lung cancer (58,245 cases; 95% CI, 57,453-59,036 cases), breast cancer (26,271 cases; 95% CI, 25,672-26,870 cases), and melanoma (20,298 cases; 95% CI, 19,897-20,699 cases). Metastasectomy increased significantly for all cancer types over the study period: colorectal cancer (AAPC, 6.83; 95% CI, 5.7-7.9), lung cancer (AAPC, 5.8; 95% CI, 5.1-6.4), breast cancer (AAPC, 5.5; 95% CI, 3.7-7.3), and melanoma (AAPC, 4.03; 95% CI, 2.1-6.0). Despite an increasing number of comorbidities in patients undergoing metastasectomy (P<.05 for each cancer type), inpatient mortality rates after metastasectomy fell for all cancer types, most significantly for colorectal (AAPC, -5.49; 95% CI, -8.2 to -2.7) and lung (AAPC, -6.2; 95% CI, -11.7 to -0.3) cancers. The increasing performance of metastasectomy was largely driven by high-volume institutions, in which patients had a lower mean number of comorbidities (P<.01 for all cancer types) and lower inpatient mortality (P<.01 for all cancers except melanoma). From 2000 through 2011, the performance of metastasectomy increased substantially across common cancer types, notwithstanding various advances in systemic therapies. Metastasectomy was performed more safely, despite increasing patient comorbidity. High-volume institutions appeared to drive practice patterns. © 2014 American Cancer Society.

CuO-Functionalized Silicon Photoanodes for Photoelectrochemical Water Splitting Devices.

PubMed

Shi, Yuanyuan; Gimbert-Suriñach, Carolina; Han, Tingting; Berardi, Serena; Lanza, Mario; Llobet, Antoni

2016-01-13

One main difficulty for the technological development of photoelectrochemical (PEC) water splitting (WS) devices is the fabrication of active, stable and cost-effective photoelectrodes that ensure high performance. Here, we report the development of a CuO/Silicon based photoanode, which shows an onset potential for the water oxidation of 0.53 V vs SCE at pH 9, that is, an overpotential of 75 mV, and high stability above 10 h. These values account for a photovoltage of 420 mV due to the absorbed photons by silicon, as proven by comparing with analogous CuO/FTO electrodes that are not photoactive. The photoanodes have been fabricated by sputtering a thin film of Cu(0) on commercially available n-type Si wafers, followed by a photoelectrochemical treatment in basic pH conditions. The resulting CuO/Cu layer acts as (1) protective layer to avoid the corrosion of nSi, (2) p-type hole conducting layer for efficient charge separation and transportation, and (3) electrocatalyst to reduce the overpotential of the water oxidation reaction. The low cost, low toxicity, and good performance of CuO-based coatings can be an attractive solution to functionalize unstable materials for solar energy conversion.

Association of vitamin D and vitamin D binding protein (DBP) gene polymorphism with susceptibility of type 2 diabetes mellitus in Bangladesh.

PubMed

Rahman, Md Mostafijur; Hosen, Md Bayejid; Faruk, Md Omar; Hasan, Md Mehedi; Kabir, Yearul; Howlader, M Zakir Hossain

2017-12-15

Polymorphism in vitamin D binding protein gene may have an impact on serum vitamin D transport and thus may have relation with type 2 diabetes mellitus. In our study, we investigated the association of serum vitamin D level and vitamin D-binding protein gene polymorphism with the onset of type 2 diabetes mellitus. Blood samples were collected from 104 type 2 diabetic patients and 107 healthy volunteers. Serum vitamin D was measured by high-performance liquid chromatography. Genetic analysis of vitamin D-binging protein gene was carried out by polymerase chain reaction - restriction fragment length polymorphism method. We found significantly (p<0.001) lower level of vitamin D in type 2 diabetic patients compared to control subjects. A significantly negative correlation (r=-0.25, p<0.05) between vitamin D level and fasting blood glucose level was found among type 2 diabetic subjects. The Glu/Glu at codon 416 (rs7041) (p<0.05) and Lys/Lys at codon 420 (rs4588) (p<0.01) variants of vitamin D binding protein gene was significantly higher in type 2 diabetic subjects than controls. The patients with Glu/Glu and Lys/Lys genotypes respectively at codon 416 (odds ratio=2.87; 95% confidence interval=1.19 to 6.95) and 420 (odds ratio=8.9; 95% confidence interval=1.89 to 41.99) were at high risk of developing type 2 diabetes. Our present study strongly suggests that there might have an association of vitamin D, and vitamin D-binding protein gene (codon 416 & 420) polymorphisms with the occurrence of type 2 diabetes mellitus. Copyright © 2017 Elsevier B.V. All rights reserved.

Recent advances in the ITO/InP solar cell

NASA Technical Reports Server (NTRS)

Gessert, T. A.; Li, X.; Wanlass, M. W.; Coutts, T. J.

1991-01-01

It was demonstrated that Indium Tin Oxide (ITO)/InP solar cells can now be made on as-received p(-) bulk substrates which are of nearly equal quality to those which could previously only be made on epitaxially grown p(-) InP base layers. Although this advancement is due in part to both increases in substrate quality and a better understanding of back contact formation, it appears that the passivation/compensation effects resulting from having H2 in the sputtering gas tends to reduce significantly the performance differences previously observed between these two substrates. It is shown that since high efficiency ITO/InP cells can be made from as-received substrates, and since the type conversion process is not highly spatially dependent, large area ITO/InP cells (4 sq cm) with efficiencies approaching 17 percent (Global) can be made. Furthermore, the measured open circuit voltages (V sub OC) and quantum efficiencies (QEs) from these large cells suggest that, when they are processed using optimum grid designs, the efficiencies will be nearly equal to that of the smaller cells thus far produced. It has been shown, through comparative experiments involving ITO/InP and IO/InP cells, that Sn may not be the major cause of type conversion of the InP surface and thus further implies that the ITO may not be an essential element in this type of device. Specifically, very efficient photovoltaic solar cells were made by sputtering (Sn free) In2O3 showing that type conversion and subsequent junction formation will occur even in the absence of the sputtered SN species. The result suggests that sputter damage may indeed be the important mechanism(s) of type conversion. Finally, an initial study of the stability of the ITO/InP cell done over the course of about one year has indicated that the J(sub SC) (short circuit current) and the fill factor (FF) are measurably stable within experimental certainty.

Few-quintuple Bi₂Te₃ nanofilms as potential thermoelectric materials.

PubMed

Zhou, Gang; Wang, Dong

2015-01-29

The thermoelectric transport properties of p-type Bi₂Te₃ nanofilms with various quintuple layers (QL) were systematically investigated based on ab initio electronic structure calculations and Boltzmann transport equations. Our results demonstrated that p-type few-quintuple Bi₂Te₃ nanofilms could exhibit high thermoelectric performance. It was found out that the 1QL Bi₂Te₃ nanofilm had the highest ZT value as compared with other nanofilms, which is mainly attributed to the significant enhancement of the density of states near the edge of the valence band resulting from the strong coupling between the top and bottom electronic states and the quantum confinement effect. The dependence of the thermoelectric transport properties on carrier concentration and temperature was also discussed in detail, which can be useful for searching high-efficiency few-quintuple Bi₂Te₃ thermoelectric nanofilms.

Effect of p-GaN layer grown with H2 carrier gas on wall-plug efficiency of high-power LEDs

NASA Astrophysics Data System (ADS)

Lu, Kuan Fu; Lin, Tien Kun; Liou, Jian Kai; Yang, Chyi Da; Lee, Chong Yi; Tsai, Jeng Da

2017-06-01

The effect of employing different carrier gases (H2 only and 1:1 vol% N2:H2) in the p-type GaN (p-GaN) layer on the wall-plug efficiency (WPE) of high-power light-emitting diodes (LEDs) is studied. Since GaN crystal could be a two-dimension (2-D) growth mode in H2 ambient, better quality and smoother surface of the p-GaN were obtained. The current spreading performance of the p-GaN layer using H2 alone as the carrier gas was enhanced, resulting in advanced light output power (LOP). In addition, turn-on voltage and dynamic resistance at 500 mA, which can strongly contribute to the WPE, were also reduced by 0.12 V and 0.13 Ω, respectively. The studied device with H2 as the carrier gas in the p-GaN layer (p-H2 layer) exhibits 9.5% and 12.4% improvements in LOP and WPE at 500 mA over the device (N2/H2 = 1:1), as well as significantly better electrostatic discharge robustness. Therefore, the use of a p-H2 layer can effectively improve the performance of GaN-based LEDs for high power applications.

Application of quantitative PCR assays for diagnosing Ikeda and other Theileria orientalis types to examine associations between severity of anaemia and parasitaemia in bovine anaemia outbreaks.

PubMed

Gias, E; Pulford, D J; Lawrence, K; McFadden, Amj

2016-01-01

To use quantitative PCR assays to detect Theileria orientalis Ikeda type in cattle presumed infected with T. orientalis, to examine the relationship between theilerial piroplasm count and haematocrit (HCT), and the relationship with quantification cycle threshold (Cq) values. Blood samples in EDTA (n=1,024), derived from herds affected by anaemia associated with T. orientalis infection (TABA) between April and October 2013, were submitted for testing using quantitative PCR (qPCR) assays for T. orientalis and Ikeda type. Nucleotide sequencing of the major piroplasm surface protein (MPSP) gene was performed on 16 samples to identify T. orientalis types. Blood smear and/or HCT results were supplied with most samples. For data analysis, the number of theilerial piroplasm per 1,000 erythrocytes counted was categorised as negative (0), low (1-9), moderate (10-100) or high (>100). HCT was categorised as severely anaemic (<0.15 L/L), mildly anaemic (0.15-0.24 L/L) or not anaemic (>0.24 L/L). Differences between categories in proportion of samples positive for Ikeda type or mean Cq value were examined using χ(2) tests or analysis of variance, respectively. Of 1,022 samples containing amplifiable DNA, 916 (90%) were positive for T. orientalis and 789 (77%) were positive for Ikeda type. Nucleotide sequencing of MPSP amplicons also identified the presence of Chitose and Buffeli types in 11 samples without Ikeda. Ikeda was detected in a greater proportion of severely anaemic (288/302; 95%) than mildly anaemic (227/252; 90%) cattle (p=0.02). In non-anaemic cattle, 344/406 (85%) were positive for T. orientalis and 247/406 (60%) were positive for Ikeda type. In samples from cattle that were piroplasm-positive, a greater proportion of anaemic (483/505, 96%) than non-anaemic (211/307; 69%) cattle were positive for Ikeda type (p<0.001). In piroplasm-negative cattle, 20/37 (54%) anaemic and 25/78 (32%) non-anaemic cattle were Ikeda-positive (p<0.05). The distributions of Cq values differed between piroplasm count and HCT categories (p<0.001). Mean Cq differed between high and negative, and low piroplasm categories (p<0.001), but not between high and moderate categories (p=0.81), and differed between severely anaemic and mildly anaemic (p<0.001), and non-anaemic categories (p<0.001). The Ikeda type was found in a high proportion of cattle during outbreaks of TABA in New Zealand. Analysis of Cq values suggested a relationship of Ikeda parasitaemia with severity of anaemia, but further investigation is required to better understand the role of parasitaemia in the pathogenesis of TABA.

Effects of creep feeding, zeranol implants and breed type on beef production: I. Calf and cow performance.

PubMed

Prichard, D L; Hargrove, D D; Olson, T A; Marshall, T T

1989-03-01

A 2-yr study was conducted to evaluate the effects of a high-energy creep feed, preweaning zeranol implants and breed type on calf and cow performance. Two hundred calves sired by Brahman and Romana Red bulls out of Angus and Angus x Brown Swiss reciprocal crossbred (F1) dams were stratified by breed type and sex to three creep treatments: no creep feed (NC); long-term creep (LC), creep-fed from 56 to 210 d of age (weaning); and short-term creep (SC), creep-fed from 146 to 210 d of age. Alternate calves within sex, breed type and creep treatment were implanted with 36 mg of zeranol at an average of 56 d and reimplanted 90 d later. The LC and SC calves had heavier (P less than .001) 210-d weights than NC calves (264 and 257 vs 231 kg, respectively), and the LC calves were heavier (P less than .001) at 146 d than NC calves. The LC calves had higher (P less than .001) ADG from 118 to 210 d of age and higher 146 and 210-d condition scores than did NC calves. Pregnancy rate was not affected (P greater than .46) by creep treatment of calf. Zeranol implants increased (P less than .01) 146- and 210-d weights (184 vs 175 kg and 259 vs 243 kg) and ADG during all periods to weaning. Brahman-sired calves had higher (P less than .005) 146- and 210-d weaning weights and frame scores than Romana Red-sired calves.(ABSTRACT TRUNCATED AT 250 WORDS)

Association between microfibrillar-associated protein 4 (MFAP4) and micro- and macrovascular complications in long-term type 1 diabetes mellitus.

PubMed

Blindbæk, S L; Schlosser, A; Green, A; Holmskov, U; Sorensen, G L; Grauslund, J

2017-04-01

To evaluate microfibrillar-associated protein 4 (MFAP4) as a marker of micro- and macrovascular complications in patients with type 1 diabetes. This cross-sectional study included 203 persons with a long duration of type 1 diabetes from a population-based cohort ascertained in the former Funen County, Denmark. Detection of plasma-MFAP4 (pMFAP4) was performed by the AlphaLISA Technique. Diabetic retinopathy (DR) was graded in accordance with the Early Treatment Diabetic Retinopathy Study adaptation of the modified Airlie House classification. A monofilament test was used to test for neuropathy, and nephropathy was evaluated in a single spot urine sample. Data describing macrovascular disease were obtained from the Danish National Patient Register. Median age and duration of diabetes were 58.7 and 43 years, respectively, and 61% were males. High levels of pMFAP4 were found in participants of old age, in women and in non-smokers (p < 0.05). In a multiple logistic regression model, patients with high levels of pMFAP4 were more likely to have diabetic neuropathy (OR 2.47 for quartile 4 versus quartile 1, 95% CI 1.01-6.03). No association was found between pMFAP4 and proliferative diabetic retinopathy, nephropathy or macrovascular disease. No association between pMFAP4 and macrovascular vascular complications was found. However, high levels of pMFAP4 correlated independently with diabetic neuropathy. Further studies on the predictive value of increased circulating MFAP4 in diabetic neuropathy are warranted.

Capacity building and predictors of success for HIV-1 drug resistance testing in the Asia-Pacific region and Africa

PubMed Central

Land, Sally; Zhou, Julian; Cunningham, Philip; Sohn, Annette H; Singtoroj, Thida; Katzenstein, David; Mann, Marita; Sayer, David; Kantor, Rami

2013-01-01

Background The TREAT Asia Quality Assessment Scheme (TAQAS) was developed as a quality assessment programme through expert education and training, for laboratories in the Asia-Pacific and Africa that perform HIV drug-resistance (HIVDR) genotyping. We evaluated the programme performance and factors associated with high-quality HIVDR genotyping. Methods Laboratories used their standard protocols to test panels of human immunodeficiency virus (HIV)-positive plasma samples or electropherograms. Protocols were documented and performance was evaluated according to a newly developed scoring system, agreement with panel-specific consensus sequence, and detection of drug-resistance mutations (DRMs) and mixtures of wild-type and resistant virus (mixtures). High-quality performance was defined as detection of ≥95% DRMs. Results Over 4.5 years, 23 participating laboratories in 13 countries tested 45 samples (30 HIV-1 subtype B; 15 non-B subtypes) in nine panels. Median detection of DRMs was 88–98% in plasma panels and 90–97% in electropherogram panels. Laboratories were supported to amend and improve their test outcomes as appropriate. Three laboratories that detected <80% DRMs in early panels demonstrated subsequent improvement. Sample complexity factors – number of DRMs (p<0.001) and number of DRMs as mixtures (p<0.001); and laboratory performance factors – detection of mixtures (p<0.001) and agreement with consensus sequence (p<0.001), were associated with high performance; sample format (plasma or electropherogram), subtype and genotyping protocol were not. Conclusion High-quality HIVDR genotyping was achieved in the TAQAS collaborative laboratory network. Sample complexity and detection of mixtures were associated with performance quality. Laboratories conducting HIVDR genotyping are encouraged to participate in quality assessment programmes. PMID:23845227

An all-solid-state perovskite-sensitized solar cell based on the dual function polyaniline as the sensitizer and p-type hole-transporting material

NASA Astrophysics Data System (ADS)

Xiao, Yaoming; Han, Gaoyi; Chang, Yunzhen; Zhou, Haihan; Li, Miaoyu; Li, Yanping

2014-12-01

High performance dual function of polyaniline (PANI) with brachyplast structure is synthesized by using a two-step cyclic voltammetry (CV) approach onto the fluorinated tin oxide (FTO) glass substrate, which acts as the sensitizer and p-type hole-transporting material (p-HTM) for the all-solid-state perovskite-sensitized solar cell (ass-PSSC) due to its π-π* transition and the localized polaron. The ass-PSSC based on the PANI delivers a photovoltaic conversion efficiency of 7.34%, and reduces from 7.34% to 6.71% after 1000 h, thereby 91.42% of the energy conversion efficiency is kept, indicating the device has a good long-term stability.

Development of n-type cobaltocene-encapsulated carbon nanotubes with remarkable thermoelectric property

PubMed Central

Fukumaru, Takahiro; Fujigaya, Tsuyohiko; Nakashima, Naotoshi

2015-01-01

Direct conversion from heat to electricity is one of the important technologies for a sustainable society since large quantities of energy are wasted as heat. We report the development of a single-walled carbon nanotube (SWNT)-based high conversion efficiency, air-stable and flexible thermoelectric material. We prepared cobaltocene-encapsulated SWNTs (denoted CoCp2@SWNTs) and revealed that the material showed a negative-type (n-type) semiconducting behaviour (Seebeck coefficient: −41.8 μV K−1 at 320 K). The CoCp2@SWNT film was found to show a high electrical conductivity (43,200 S m−1 at 320 K) and large power factor (75.4 μW m−1 K−2) and the performance was remarkably stable under atmospheric conditions over a wide range of temperatures. The thermoelectric figure of merit (ZT) value of the CoCp2@SWNT film (0.157 at 320 K) was highest among the reported n-type organic thermoelectric materials due to the large power factor and low thermal conductivity (0.15 W m−1 K−1). These characteristics of the n-type CoCp2@SWNTs allowed us to fabricate a p-n type thermoelectric device by combination with an empty SWNT-based p-type film. The fabricated device exhibited a highly efficient power generation close to the calculated values even without any air-protective coating due to the high stability of the SWNT-based materials under atmospheric conditions. PMID:25608478

A low insertion loss GaAs pHEMT switch utilizing dual n +-doping AlAs etching stop layers design

NASA Astrophysics Data System (ADS)

Chien, Feng-Tso; Lin, Da-Wei; Yang, Chih-Wei; Fu, Jeffrey S.; Chiu, Hsien-Chin

2010-03-01

A low insertion loss single-pole-single-throw (SPST) pseudomorphic high electron mobility transistor (pHEMT) switch utilizing the n +-type doping in AlAs etching stop layer was fabricated and investigated. This novel design reduces device sheet resistance resulting in an improvement of dc and rf power performance. In addition, the gate recess selectivity for GaAs/AlAs interface was not sacrificed after highly n +-type doping in AlAs etching stop layer. The pHEMT with n +-AlAs etching stop layer, also named Modified pHEMT (M-pHEMT), demonstrated a lower sheet resistance ( Rsh) of 65.9 Ω/γ, a higher maximum drain-to-source current ( Idmax) of 317.8 mA/mm and a higher peak transconductance ( gm) of 259.3 mS/mm which are superior to standard pHEMT performance with values of 71.9 Ω/γ, 290.3 mA/mm and 252.1 mS/mm, respectively. Due to a significant sheet resistance improvement from this novel epitaxial design, an SPST pHEMT switch was realized to manifest its industrial application potential. The results achieved an on-state insertion loss of 1.42 dB, an off-state isolation of 13.02 dB at 0.9 GHz, which were superior to traditional pHEMT switch under same condition of operation with values of 1.68 dB and 11.42 dB, respectively. It is proved that dual n +-doping AlAs etching stop layers scheme is beneficial for low loss microwave switches applications.

High-performance vertical organic transistors.

PubMed

Kleemann, Hans; Günther, Alrun A; Leo, Karl; Lüssem, Björn

2013-11-11

Vertical organic thin-film transistors (VOTFTs) are promising devices to overcome the transconductance and cut-off frequency restrictions of horizontal organic thin-film transistors. The basic physical mechanisms of VOTFT operation, however, are not well understood and VOTFTs often require complex patterning techniques using self-assembly processes which impedes a future large-area production. In this contribution, high-performance vertical organic transistors comprising pentacene for p-type operation and C60 for n-type operation are presented. The static current-voltage behavior as well as the fundamental scaling laws of such transistors are studied, disclosing a remarkable transistor operation with a behavior limited by injection of charge carriers. The transistors are manufactured by photolithography, in contrast to other VOTFT concepts using self-assembled source electrodes. Fluorinated photoresist and solvent compounds allow for photolithographical patterning directly and strongly onto the organic materials, simplifying the fabrication protocol and making VOTFTs a prospective candidate for future high-performance applications of organic transistors. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Efficacy of Carbohydrate Ingestion on CrossFit Exercise Performance

PubMed Central

Rountree, Jaden A.; Krings, Ben M.; Peterson, Timothy J.; Thigpen, Adam G.; McAllister, Matthew J.; Holmes, Megan E.

2017-01-01

The efficacy of carbohydrate (CHO) ingestion during high-intensity strength and conditioning type exercise has yield mixed results. However, little is known about shorter duration high-intensity exercise such as CrossFit. The purpose of this study was to investigate the performance impact of CHO ingestion during high-intensity exercise sessions lasting approximately 30 min. Eight healthy males participated in a total of four trials; two familiarizations, a CHO trial, and a similarly flavored, non-caloric placebo (PLA) trial. CrossFit’s “Fight Gone Bad Five” (FGBF) workout of the day was the exercise model which incorporated five rounds of maximal repetition exercises, wall throw, box jump, sumo deadlift high pull, push press, and rowing, followed by one minute of rest. Total repetitions and calories expended were summated from each round to quantify total work (FGBF score). No difference was found for the total work between CHO (321 ± 51) or PLA (314 ± 52) trials (p = 0.38). There were also no main effects (p > 0.05) for treatment comparing exercise performance across rounds. Based on the findings of this study, it does not appear that ingestion of CHO during short duration, high-intensity CrossFit exercise will provide a beneficial performance effect.

Typing performance and body discomfort among overweight and obese office workers: A pilot study of keyboard modification.

PubMed

Smith, Matthew Lee; Pickens, Adam W; Ahn, SangNam; Ory, Marcia G; DeJoy, David M; Young, Kristi; Bishop, Gary; Congleton, Jerome J

2015-01-01

Obesity in the workplace is associated with loss of productivity, high medical care expenses, and increased rates of work-related injuries and illness. Thus, effective, low-cost interventions are needed to accommodate the size of today's obese office worker while alleviating potential physical harm associated with musculoskeletal disorders. Utilizing a sample of 22 overweight and obese office workers, this pilot study assessed the impact of introducing an alternative, more ergonomically-sound keyboard on perceptions about design, acceptability, and usability; self-reported body discomfort; and typing productivity. Data were collected using self-reported questionnaires and objective typing tests administered before and after the intervention. The intervention duration was six weeks. After switching from their standard work keyboard to an alternative keyboard, all participants reported significant decreases in lower back discomfort (t = 2.14, P = 0.044); although obese participants reported significant decreases in both upper (t = 2.46, P = 0.032) and lower (t = 2.39, P = 0.036) back discomfort. No significant changes were observed in overall typing performance scores from baseline to follow-up. Findings suggest that such interventions may be introduced into the workforce with positive gains for workers without reducing short-term worker productivity. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Canine gastric carcinoma: immunohistochemical expression of cell cycle proteins (p53, p21, and p16) and heat shock proteins (Hsp27 and Hsp70).

PubMed

Carrasco, V; Canfrán, S; Rodríguez-Franco, F; Benito, A; Sáinz, A; Rodríguez-Bertos, A

2011-01-01

Immunohistochemical staining for cell cycle proteins and heat shock proteins was performed on 17 canine gastric carcinomas. The immunoexpression of p53, p21, p16, Hsp27, and Hsp70 was investigated. A study was conducted to determine the histological type and parameters related to tumor malignancy. Possible associations and trends were assessed between the immunoexpression of each protein and tumor type as well as specific parameters of malignancy. High intratumor frequency of cellular p53 immunostaining was observed (61.96% average), but lower frequencies of p21 and p16 expression were present (34.65% and 10.41%, respectively). The p53 overexpression was associated with tumor infiltration (P = .0258). Expression of p21 was lower in undifferentiated carcinomas, and the loss of expression was associated with histopathological parameters characteristic of a poor prognosis such as lymphatic vessel invasion (P = .0258). The lack of p16 immunoreactivity was related to histopathological characteristics of malignancy such as the presence of evident and multiple nucleoli (P = .0475). In contrast, deep tumor infiltration was observed in those carcinomas with a high p16 index (P = .0475). Hsp70 appeared to be overexpressed in all gastric neoplasms included in this study. This is in contrast to Hsp27, because a group of tumors showed complete lack of Hsp27 immunoexpression, whereas the others displayed extensive Hsp27 immunostaining. The differences in Hsp27 did not correlate with any of the histopathological parameters, but Hsp27 immunoexpression was higher in the undifferentiated carcinoma. No significant differences in the expression of the proteins were found in canine gastric carcinomas according to their histological type. These findings may be useful for establishing a prognosis for canine gastric carcinoma.

Synthesis and characterization of organic/inorganic heterostructure films for hybrid light emitting diode

NASA Astrophysics Data System (ADS)

Toyama, Toshihiko; Ichihara, Tokuyuki; Yamaguchi, Daisuke; Okamoto, Hiroaki

2007-10-01

Thin-film light emitting devices based on organic materials have been gathering attentions for applying a flat-panel display and a solid-state lighting. Alternatively, inorganic technologies such as Si-based thin-film technology have been growing almost independently. It is then expected that combining the Si-based thin-film technology with the organic light emitting diode (OLED) technology will develop innovative devices. Here, we report syntheses of the hybrid light emitting diode (LED) with a heterostructure consisting of p-type SiC x and tris-(8-hydroxyquinoline) aluminum films and characterization for the hybrid LEDs. We present the energy diagram of the heterostructure, and describe that the use of high dark conductivities of the p-type SiC x as well as inserting wide-gap intrinsic a-SiC x at the p-type SiC x/Alq interface are effective for improving device performance.

Thermoelectric properties of cerium monopnictides

NASA Technical Reports Server (NTRS)

Danielson, L. R.; Alexander, M. N.; Wood, C.; Lockwood, R. A.; Vandersande, J. W.

1987-01-01

Several cerium pnictides have been synthesized from the pure elements and hot pressed into test samples. Measurements of Seebeck coefficients and electrical resistivities were performed on these samples from room temperature to 1000 C. Cerium arsenide and cerium antimonide are n-type; cerium nitride changes from p-type to n-type conduction at 800 C. The materials are semimetals with resistivities below 1 mohm/cm. Cerium arsenide is the most favorable of the pnictides studied for high-temperature thermoelectric energy conversion, with an average power factor of 15 microW/cm K sq from 500 to 1000 C.

Prediction and theoretical characterization of p-type organic semiconductor crystals for field-effect transistor applications.

PubMed

Atahan-Evrenk, Sule; Aspuru-Guzik, Alán

2014-01-01

The theoretical prediction and characterization of the solid-state structure of organic semiconductors has tremendous potential for the discovery of new high performance materials. To date, the theoretical analysis mostly relied on the availability of crystal structures obtained through X-ray diffraction. However, the theoretical prediction of the crystal structures of organic semiconductor molecules remains a challenge. This review highlights some of the recent advances in the determination of structure-property relationships of the known organic semiconductor single-crystals and summarizes a few available studies on the prediction of the crystal structures of p-type organic semiconductors for transistor applications.

Tunnel FinFET CMOS inverter with very low short-circuit current for ultralow-power Internet of Things application

NASA Astrophysics Data System (ADS)

Morita, Yukinori; Fukuda, Koichi; Liu, Yongxun; Mori, Takahiro; Mizubayashi, Wataru; O'uchi, Shin-ichi; Fuketa, Hiroshi; Otsuka, Shintaro; Migita, Shinji; Masahara, Meishoku; Endo, Kazuhiko; Ota, Hiroyuki; Matsukawa, Takashi

2017-04-01

We have demonstrated the operation of a CMOS inverter consisting of Si tunnel FinFETs. Both p- and n-type tunnel FinFETs are successfully fabricated and operated on the same SOI wafer. The current mismatch between p- and n-type tunnel FETs is compensated by tuning the number of fin channels. Very low short-circuit current and clear voltage input-output characteristics are obtained. The thin epitaxial channel in the tunnel FinFETs effectively increases the drain current and accordingly reduces the drain capacitance, which could help high-performance tunnel FET CMOS inverter operation.

Solid state synthesis of layered sodium manganese oxide for sodium-ion battery by in-situ high energy X-ray diffraction and X-ray absorption near edge spectroscopy [Solid state synthesis of layered sodium manganese oxide for sodium-ion battery by in-situ HEXRD and XANES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Tianyuan; Xu, Gui -Liang; Zeng, Xiaoqiao

In situ high energy X-ray diffraction (HEXRD) and in situ X-ray absorption near edge spectroscopy (XANES) were carried out to understand the soild state synthesis of Na xMnO 2, with particular interest on the synthesis of P2 type Na 2/3MnO 2. It was found that there were multi intermediate phases formed before NaMnO 2 appeared at about 600 °C. And the final product after cooling process is a combination of O'3 NaMnO 2 with P2 Na 2/3MnO 2. A P2 type Na 2/3MnO 2 was synthesized at reduced temperature (600 °C). The influence of Na 2CO 3 impurity on themore » electrochemical performance of P2 Na 2/3MnO 2 was thoroughly investigated in our work. It was found that the content of Na 2CO 3 can be reduced by optimizing Na 2CO 3/MnCO 3 ratio during the solid state reaction or other post treatment such as washing with water. Lastly, we expected our results could provide a good guide for future development of high performance cathode materials for sodium-ion batteries.« less

Solid state synthesis of layered sodium manganese oxide for sodium-ion battery by in-situ high energy X-ray diffraction and X-ray absorption near edge spectroscopy [Solid state synthesis of layered sodium manganese oxide for sodium-ion battery by in-situ HEXRD and XANES

DOE PAGES

Ma, Tianyuan; Xu, Gui -Liang; Zeng, Xiaoqiao; ...

2016-12-07

In situ high energy X-ray diffraction (HEXRD) and in situ X-ray absorption near edge spectroscopy (XANES) were carried out to understand the soild state synthesis of Na xMnO 2, with particular interest on the synthesis of P2 type Na 2/3MnO 2. It was found that there were multi intermediate phases formed before NaMnO 2 appeared at about 600 °C. And the final product after cooling process is a combination of O'3 NaMnO 2 with P2 Na 2/3MnO 2. A P2 type Na 2/3MnO 2 was synthesized at reduced temperature (600 °C). The influence of Na 2CO 3 impurity on themore » electrochemical performance of P2 Na 2/3MnO 2 was thoroughly investigated in our work. It was found that the content of Na 2CO 3 can be reduced by optimizing Na 2CO 3/MnCO 3 ratio during the solid state reaction or other post treatment such as washing with water. Lastly, we expected our results could provide a good guide for future development of high performance cathode materials for sodium-ion batteries.« less

Engineering a highly active thermophilic β-glucosidase to enhance its pH stability and saccharification performance.

PubMed

Xia, Wei; Xu, Xinxin; Qian, Lichun; Shi, Pengjun; Bai, Yingguo; Luo, Huiying; Ma, Rui; Yao, Bin

2016-01-01

β-Glucosidase is an important member of the biomass-degrading enzyme system, and plays vital roles in enzymatic saccharification for biofuels production. Candidates with high activity and great stability over high temperature and varied pHs are always preferred in industrial practice. To achieve cost-effective biomass conversion, exploring natural enzymes, developing high level expression systems and engineering superior mutants are effective approaches commonly used. A newly identified β-glucosidase of GH3, Bgl3A, from Talaromyces leycettanus JCM12802, was overexpressed in yeast strain Pichia pastoris GS115, yielding a crude enzyme activity of 6000 U/ml in a 3 L fermentation tank. The purified enzyme exhibited outstanding enzymatic properties, including favorable temperature and pH optima (75 °C and pH 4.5), good thermostability (maintaining stable at 60 °C), and high catalytic performance (with a specific activity and catalytic efficiency of 905 U/mg and 9096/s/mM on pNPG, respectively). However, the narrow stability of Bgl3A at pH 4.0-5.0 would limit its industrial applications. Further site-directed mutagenesis indicated the role of excessive O-glycosylation in pH liability. By removing the potential O-glycosylation sites, two mutants showed improved pH stability over a broader pH range (3.0-10.0). Besides, with better stability under pH 5.0 and 50 °C compared with wild type Bgl3A, saccharification efficiency of mutant M1 was improved substantially cooperating with cellulase Celluclast 1.5L. And mutant M1 reached approximately equivalent saccharification performance to commercial β-glucosidase Novozyme 188 with identical β-glucosidase activity, suggesting its great prospect in biofuels production. In this study, we overexpressed a novel β-glucosidase Bgl3A with high specific activity and high catalytic efficiency in P. pastoris. We further proved the negative effect of excessive O-glycosylation on the pH stability of Bgl3A, and enhanced the pH stability by reducing the O-glycosylation. And the enhanced mutants showed much better application prospect with substantially improved saccharification efficiency on cellulosic materials.

Exercising in a hot environment: which T-shirt to wear?

PubMed

Sperlich, Billy; Born, Dennis-Peter; Lefter, Marie Denise; Holmberg, Hans-Christer

2013-09-01

The aim of this study was to investigate thermoregulatory, cardiorespiratory, metabolic, and perceptual responses while running in a hot environment (31.7° ± 1.0°C; 42% ± 3% relative humidity) and wearing T-shirts made from different fiber types. Eight well-trained men performed 4 tests wearing either a T-shirt made of 100% polyester with 4, 6, or 8 channels, or one made of 100% cotton. Each test consisted of 30 minutes running at 70% of peak oxygen uptake, followed by a ramp test to exhaustion and 15 minutes of recovery. There were no differences in skin, core, and body temperatures between fiber types during submaximal and high-intensity running (best P = .08). During recovery, body temperature and shivering/sweating sensations were lower when wearing 4- and 6-channel fibers (P ≤ .04) compared with cotton. The relative humidity at the chest and back were lower for all polyester T-shirts compared with cotton during and after submaximal and maximal running (P ≤ .007). Heart rate (best P = .10), oxygen uptake (P = .95), respiratory exchange ratio (best P = .93), ventilation (best P = .99), and blood lactate concentration (best P = .97) did not differ between the fiber types. Nor were any differences in time to exhaustion (best P = .76), ratings of perceived exertion (best P = .09), thermal sensation (best P = .07), or sensation of clothing wetness (best P = .36) discovered. Although statistical analysis revealed lower shivering/sweating sensations while wearing 4- and 6-channel fiber shirts during recovery, with an improved chest and back microenvironment for all polyester T-shirts, the question remains whether these differences are of any practical relevance because the performance of the well-trained men was unaffected. Wilderness Medical Society.

HR-HPV E6/E7 mRNA In Situ Hybridization: Validation Against PCR, DNA In Situ Hybridization, and p16 Immunohistochemistry in 102 Samples of Cervical, Vulvar, Anal, and Head and Neck Neoplasia.

PubMed

Mills, Anne M; Dirks, Dawn C; Poulter, Melinda D; Mills, Stacey E; Stoler, Mark H

2017-05-01

Dysregulated expression of oncogenic types of E6 and E7 is necessary for human papillomavirus (HPV)-driven carcinogenesis. An HPV E6/E7 mRNA in situ hybridization (ISH) assay covering 18 common high-risk types ("HR-RISH," aka HR-HPV RNA18 ISH) has not been extensively studied in the anogenital tract or validated on automated technology. We herein compare HR-RISH to DNA polymerase chain reaction (PCR), p16 immunohistochemistry, and a previously available HPV DNA ISH assay in HPV-related anogenital and head and neck (H&N) neoplasia. A total of 102 squamous intraepithelial lesions (16 CIN1, 25 CIN3, 3 AIN1, 12 AIN3, 9 VIN3)/invasive squamous cell carcinomas (17 cervical, 2 anal, 18 H&N) as well as 10 normal and 15 reactive cervix samples were collected. HR-RISH, DNA ISH, and p16 immunohistochemistry were performed on whole formalin-fixed, paraffin-embedded sections. RNA ISH for 6 low-risk HPV types (LR-RISH) was also performed. RNA and DNA ISH assays used automated systems. HR-HPV PCR was performed on morphology-directed formalin-fixed, paraffin-embedded punches. HR-RISH was ≥97% sensitive for PCR+ and p16+ neoplasia, as well as morphologically defined anogenital high grade squamous intraepithelial lesion/invasive squamous cell carcinoma. HR-RISH was also positive in 78% of anogenital low grade squamous intraepithelial lesion, including 81% of CIN1. Furthermore, a subset of PCR-negative/invalid and p16-negative lesions was positive for HR-RISH. Only 1 problematic reactive cervix sample and no normal cervix samples stained. These results demonstrate that HR-RISH is a robust method for the detection of HR-HPV-related neoplasia and provides insight into HPV pathobiology. Performance meets or exceeds that of existing assays in anogenital and H&N lesions and may play a role in resolving diagnostically challenging CIN1 versus reactive cases.

Bottom-up design of de novo thermoelectric hybrid materials using chalcogenide resurfacing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sahu, Ayaskanta; Russ, Boris; Su, Norman C.

Hybrid organic/inorganic thermoelectric materials based on conducting polymers and inorganic nanostructures have been demonstrated to combine both the inherently low thermal conductivity of the polymer and the superior charge transport properties (high power factors) of the inorganic component. While their performance today still lags behind that of conventional inorganic thermoelectric materials, solution-processable hybrids have made rapid progress and also offer unique advantages not available to conventional rigid inorganic thermoelectrics, namely: (1) low cost fabrication on rigid and flexible substrates, as well as (2) engineering complex conformal geometries for energy harvesting/cooling. While the number of reports of new classes of viablemore » hybrid thermoelectric materials is growing, no group has reported a general approach for bottom-up design of both p- and n-type materials from one common base. Thus, unfortunately, the literature comprises mostly of disconnected discoveries, which limits development and calls for a first-principles approach for property manipulation analogous to doping in traditional semiconductor thermoelectrics. Here, molecular engineering at the organic/inorganic interface and simple processing techniques are combined to demonstrate a modular approach enabling de novo design of complex hybrid thermoelectric systems. Here, we chemically modify the surfaces of inorganic nanostructures and graft conductive polymers to yield robust solution processable p- and n-type inorganic/organic hybrid nanostructures. Our new modular approach not only offers researchers new tools to perform true bottom-up design of thermoelectric hybrids, but also strong performance advantages as well due to the quality of the designed interfaces. For example, we obtain enhanced power factors in existing (by up to 500% in Te/PEDOT:PSS) and novel (Bi 2S 3/PEDOT:PSS) p-type systems, and also generate water-processable and air-stable high performing n-type hybrid systems (Bi 2Te 3/PEDOT:PSS), thus highlighting the potency of our ex situ strategy in opening up new material options for thermoelectric applications. Finally, this strategy establishes a unique platform with broad handles for custom tailoring of thermal and electrical properties through hybrid material tunability and enables independent control over inorganic material chemistry, nanostructure geometry, and organic material properties, thus providing a robust pathway to major performance enhancements.« less

Bottom-up design of de novo thermoelectric hybrid materials using chalcogenide resurfacing

DOE PAGES

Sahu, Ayaskanta; Russ, Boris; Su, Norman C.; ...

2017-01-01

Hybrid organic/inorganic thermoelectric materials based on conducting polymers and inorganic nanostructures have been demonstrated to combine both the inherently low thermal conductivity of the polymer and the superior charge transport properties (high power factors) of the inorganic component. While their performance today still lags behind that of conventional inorganic thermoelectric materials, solution-processable hybrids have made rapid progress and also offer unique advantages not available to conventional rigid inorganic thermoelectrics, namely: (1) low cost fabrication on rigid and flexible substrates, as well as (2) engineering complex conformal geometries for energy harvesting/cooling. While the number of reports of new classes of viablemore » hybrid thermoelectric materials is growing, no group has reported a general approach for bottom-up design of both p- and n-type materials from one common base. Thus, unfortunately, the literature comprises mostly of disconnected discoveries, which limits development and calls for a first-principles approach for property manipulation analogous to doping in traditional semiconductor thermoelectrics. Here, molecular engineering at the organic/inorganic interface and simple processing techniques are combined to demonstrate a modular approach enabling de novo design of complex hybrid thermoelectric systems. Here, we chemically modify the surfaces of inorganic nanostructures and graft conductive polymers to yield robust solution processable p- and n-type inorganic/organic hybrid nanostructures. Our new modular approach not only offers researchers new tools to perform true bottom-up design of thermoelectric hybrids, but also strong performance advantages as well due to the quality of the designed interfaces. For example, we obtain enhanced power factors in existing (by up to 500% in Te/PEDOT:PSS) and novel (Bi 2S 3/PEDOT:PSS) p-type systems, and also generate water-processable and air-stable high performing n-type hybrid systems (Bi 2Te 3/PEDOT:PSS), thus highlighting the potency of our ex situ strategy in opening up new material options for thermoelectric applications. Finally, this strategy establishes a unique platform with broad handles for custom tailoring of thermal and electrical properties through hybrid material tunability and enables independent control over inorganic material chemistry, nanostructure geometry, and organic material properties, thus providing a robust pathway to major performance enhancements.« less

[Neck lymphatic metastasis, surgical methods and prognosis in early tongue squamous cell carcinoma].

PubMed

Wang, L S; Zhou, F T; Han, C B; He, X P; Zhang, Z X

2018-02-09

Objective: To investigate the different pattern of neck lymph node metastasis, the choice of surgical methods and prognosis in early tongue squamous cell carcinoma. Methods: A total of 157 patients with early oral tongue squamous cell carcinoma were included in this study. Statistical analysis was performed to identify the pattern of lymph node metastasis, to determine the best surgical procedure and to analyze the prognosis. Results: The occurrence of cervical lymph node metastasis rate was 31%(48/157). Neck lymphatic metastasis was significantly related to tumor size ( P= 0.026) and histology differentiation type ( P= 0.022). The rate of metastasis was highest in level Ⅱ [33% (16/48)]. In level Ⅳ, the incidence of lymph node metastasis was 5%(7/157), and there was no skip metastases. The possibility of level Ⅳ metastasis was higher, when level Ⅱ ( P= 0.000) or Ⅲ ( P= 0.000) involved. The differentiation tumor recurrence, neck lymphatic metastasis and adjuvant radiotherapy were prognostic factors ( P< 0.05). Multivariate analyses revealed histology differentiation type, neck lymphatic metastases and adjuvant radiotherapy were the independent prognostic factors. Conclusions: Neck lymphatic metastasis rate is high in early tongue squamous cell carcinoma, simultaneous glossectomy and neck dissection should be performed. Level Ⅳ metastasis rate is extremely low, so supraomohyoid neck dissection is sufficient for most of the time. The histology differentiation type, neck lymphatic metastasis and adjuvant radiotherapy are independent prognostic factors.

High-performance Ge p-i-n photodetector on Si substrate

NASA Astrophysics Data System (ADS)

Chen, Li-qun; Huang, Xiang-ying; Li, Min; Huang, Yan-hua; Wang, Yue-yun; Yan, Guang-ming; Li, Cheng

2015-05-01

High-performance and tensile-strained germanium (Ge) p-i-n photodetector is demonstrated on Si substrate. The epitaxial Ge layers were prepared in an ultrahigh vacuum chemical vapor deposition (UHV-CVD) system using low temperature Ge buffer technique. The devices were fabricated by in situ doping and using Si as passivation layer between Ge and metal, which can improve the ohmic contact and realize the high doping. The results show that the dark current of the photodetector with diameter of 24 μm is about 2.5×10-7 μA at the bias voltage of -1 V, and the optical responsivity is 0.1 A/W at wavelength of 1.55 μm. The 3 dB bandwidth (BW) of 4 GHz is obtained for the photodetector with diameter of 24 μm at reverse bias voltage of 1 V. The long diffusion time of minority carrier in n-type Ge and the large contact resistance in metal/Ge contacts both affect the performance of Ge photodetectors.

High-Performance Screen-Printed Thermoelectric Films on Fabrics

DOE PAGES

Shin, Sunmi; Kumar, Rajan; Roh, Jong Wook; ...

2017-08-04

Printing techniques could offer a scalable approach to fabricate thermoelectric (TE) devices on flexible substrates for power generation used in wearable devices and personalized thermo-regulation. However, typical printing processes need a large concentration of binder additives, which often render a detrimental effect on electrical transport of the printed TE layers. Here, we report scalable screenprinting of TE layers on flexible fiber glass fabrics, by rationally optimizing the printing inks consisting of TE particles (p-type Bi 0.5Sb 1.5Te 3 or n-type Bi 2Te 2.7Se 0.3), binders, and organic solvents. We identified a suitable binder additive, methyl cellulose, which offers suitable viscositymore » for printability at a very small concentration (0.45–0.60 wt.%), thus minimizing its negative impact on electrical transport. Following printing, the binders were subsequently burnt off via sintering and hot pressing. We found that the nanoscale defects left behind after the binder burnt off became effective phonon scattering centers, leading to low lattice thermal conductivity in the printed n-type material. With the high electrical conductivity and low thermal conductivity, the screen-printed TE layers showed high room-temperature ZT values of 0.65 and 0.81 for p-type and n-type, respectively.« less

High-Performance Screen-Printed Thermoelectric Films on Fabrics.

PubMed

Shin, Sunmi; Kumar, Rajan; Roh, Jong Wook; Ko, Dong-Su; Kim, Hyun-Sik; Kim, Sang Il; Yin, Lu; Schlossberg, Sarah M; Cui, Shuang; You, Jung-Min; Kwon, Soonshin; Zheng, Jianlin; Wang, Joseph; Chen, Renkun

2017-08-04

Printing techniques could offer a scalable approach to fabricate thermoelectric (TE) devices on flexible substrates for power generation used in wearable devices and personalized thermo-regulation. However, typical printing processes need a large concentration of binder additives, which often render a detrimental effect on electrical transport of the printed TE layers. Here, we report scalable screen-printing of TE layers on flexible fiber glass fabrics, by rationally optimizing the printing inks consisting of TE particles (p-type Bi 0.5 Sb 1.5 Te 3 or n-type Bi 2 Te 2.7 Se 0.3 ), binders, and organic solvents. We identified a suitable binder additive, methyl cellulose, which offers suitable viscosity for printability at a very small concentration (0.45-0.60 wt.%), thus minimizing its negative impact on electrical transport. Following printing, the binders were subsequently burnt off via sintering and hot pressing. We found that the nanoscale defects left behind after the binder burnt off became effective phonon scattering centers, leading to low lattice thermal conductivity in the printed n-type material. With the high electrical conductivity and low thermal conductivity, the screen-printed TE layers showed high room-temperature ZT values of 0.65 and 0.81 for p-type and n-type, respectively.

High-Performance Screen-Printed Thermoelectric Films on Fabrics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shin, Sunmi; Kumar, Rajan; Roh, Jong Wook

Printing techniques could offer a scalable approach to fabricate thermoelectric (TE) devices on flexible substrates for power generation used in wearable devices and personalized thermo-regulation. However, typical printing processes need a large concentration of binder additives, which often render a detrimental effect on electrical transport of the printed TE layers. Here, we report scalable screenprinting of TE layers on flexible fiber glass fabrics, by rationally optimizing the printing inks consisting of TE particles (p-type Bi 0.5Sb 1.5Te 3 or n-type Bi 2Te 2.7Se 0.3), binders, and organic solvents. We identified a suitable binder additive, methyl cellulose, which offers suitable viscositymore » for printability at a very small concentration (0.45–0.60 wt.%), thus minimizing its negative impact on electrical transport. Following printing, the binders were subsequently burnt off via sintering and hot pressing. We found that the nanoscale defects left behind after the binder burnt off became effective phonon scattering centers, leading to low lattice thermal conductivity in the printed n-type material. With the high electrical conductivity and low thermal conductivity, the screen-printed TE layers showed high room-temperature ZT values of 0.65 and 0.81 for p-type and n-type, respectively.« less

Configural frequency analysis as a method of determining patients' preferred decision-making roles in dialysis.

PubMed

Loeffert, Sabine; Ommen, Oliver; Kuch, Christine; Scheibler, Fueloep; Woehrmann, Andrej; Baldamus, Conrad; Pfaff, Holger

2010-09-11

Numerous studies examined factors in promoting a patient preference for active participation in treatment decision making with only modest success. The purpose of this study was to identify types of patients wishing to participate in treatment decisions as well as those wishing to play a completely active or passive role based on a Germany-wide survey of dialysis patients; using a prediction typal analysis method that defines types as configurations of categories belonging to different attributes and takes particularly higher order interactions between variables into account. After randomly splitting the original patient sample into two halves, an exploratory prediction configural frequency analysis (CFA) was performed on one-half of the sample (n = 1969) and the identified types were considered as hypotheses for an inferential prediction CFA for the second half (n = 1914). 144 possible prediction types were tested by using five predictor variables and control preferences as criterion. An α-adjustment (0.05) for multiple testing was performed by the Holm procedure. 21 possible prediction types were identified as hypotheses in the exploratory prediction CFA; four patient types were confirmed in the confirmatory prediction CFA: patients preferring a passive role show low information seeking preference, above average trust in their physician, perceive their physician's participatory decision-making (PDM)-style positive, have a lower educational level, and are 56-75 years old (Type 1; p < 0.001) or > 76 years old (Type 2; p < 0.001). Patients preferring an active role show high information seeking preference, a higher educational level, and are < 55 years old. They have either below average trust, perceive the PDM-style negative (Type 3; p < 0.001) or above average trust and perceive the PDM-style positive (Type 4; p < 0.001). The method prediction configural frequency analysis was newly introduced to the research field of patient participation and could demonstrate how a particular control preference role is determined by an association of five variables.

Is serum Klotho protective against atherosclerosis in patients with type 1 diabetes mellitus?

PubMed

Keles, Nursen; Dogan, Burcu; Kalcik, Macit; Caliskan, Mustafa; Keles, Necibe Nur; Aksu, Feyza; Bulut, Mustafa; Kostek, Osman; Isbilen, Banu; Yilmaz, Yusuf; Oguz, Aytekin

2016-01-01

Klotho deficiency is associated with several metabolic disorders. Two dimensional (2D) longitudinal strain (LS) of left ventricle (LV), carotid artery intima-media thickness (CIMT), flow-mediated dilation (FMD) of brachial artery and epicardial fat thickness (EFT) have been reported to be early predictors of atherosclerosis. We aimed to investigate the relationship between serum Klotho levels and these early predictors of atherosclerosis in patients with type 1 diabetes mellitus (DM). The study included 45 type 1 diabetic patients and 35 controls. Serum Klotho levels were determined by ELISA method. The patient group was also divided into two subgroups according to serum Klotho levels: high (HK) and low Klotho (LK) groups. EFT, CIMT and FMD were measured according to appropriate recommendations. Speckle tracking analysis was performed using the Echopac software. The patient group had significantly lower serum Klotho (p=0.001), FMD (p<0.001) and LS of LV (p<0.001) values, but larger EFT (p<0.001) and CIMT (p<0.001) values than controls. LK subgroup had also significantly lower FMD (p<0.001) and LS of LV (p<0.001) but larger EFT (p=0.002) and CIMT (p<0.001) values than HK subgroup. Serum Klotho may have a protective effect against atherosclerosis and endothelial dysfunction in type 1 DM. Copyright © 2016 Elsevier Inc. All rights reserved.

Clinical MRSA isolates from skin and soft tissue infections show increased in vitro production of phenol soluble modulins

PubMed Central

Berlon, Nicholas R.; Qi, Robert; Sharma-Kuinkel, Batu K.; Joo, Hwang-Soo; Park, Lawrence P.; George, Dennis; Thaden, Joshua T.; Messina, Julia A.; Maskarinec, Stacey A.; Mueller-Premru, Manica; Athan, Eugene; Tattevin, Pierre; Pericas, Juan M.; Woods, Christopher W.; Otto, Michael; Fowler, Vance G.

2016-01-01

Summary Background Phenol-soluble modulins (PSMs) are amphipathic, pro-inflammatory proteins secreted by most Staphylococcus aureus isolates. This study tested the hypothesis that in vitro PSM production levels are associated with specific clinical phenotypes. Methods 177 methicillin-resistant S. aureus (MRSA) isolates from infective endocarditis (IE), skin and soft tissue infection (SSTI), and hospital-acquired/ventilator-associated pneumonia (HAP) were matched by geographic origin, then genotyped using spa-typing. In vitro PSM production was measured by high performance liquid chromatography/mass spectrometry. Statistical analysis was performed using Chi-squared or Kruskal–Wallis tests as appropriate. Results Spa type 1 was significantly more common in SSTI isolates (62.7% SSTI; 1.7% IE; 16.9% HAP; p < 0.0001) while HAP and IE isolates were more commonly spa type 2 (0% SSTI; 37.3% IE; 40.7% HAP; p < 0.0001). USA300 isolates produced the highest levels of PSMs in vitro. SSTI isolates produced significantly higher quantities of PSMα1-4, PSMβ1, and δ-toxin than other isolates (p < 0.001). These findings persisted when USA300 isolates were excluded from analysis. PMID:26079275

Band Structures and Transport Properties of High-Performance Half-Heusler Thermoelectric Materials by First Principles.

PubMed

Fang, Teng; Zhao, Xinbing; Zhu, Tiejun

2018-05-19

Half-Heusler (HH) compounds, with a valence electron count of 8 or 18, have gained popularity as promising high-temperature thermoelectric (TE) materials due to their excellent electrical properties, robust mechanical capabilities, and good high-temperature thermal stability. With the help of first-principles calculations, great progress has been made in half-Heusler thermoelectric materials. In this review, we summarize some representative theoretical work on band structures and transport properties of HH compounds. We introduce how basic band-structure calculations are used to investigate the atomic disorder in n-type M NiSb ( M = Ti, Zr, Hf) compounds and guide the band engineering to enhance TE performance in p-type Fe R Sb ( R = V, Nb) based systems. The calculations on electrical transport properties, especially the scattering time, and lattice thermal conductivities are also demonstrated. The outlook for future research directions of first-principles calculations on HH TE materials is also discussed.

Band Structures and Transport Properties of High-Performance Half-Heusler Thermoelectric Materials by First Principles

PubMed Central

Fang, Teng; Zhao, Xinbing

2018-01-01

Half-Heusler (HH) compounds, with a valence electron count of 8 or 18, have gained popularity as promising high-temperature thermoelectric (TE) materials due to their excellent electrical properties, robust mechanical capabilities, and good high-temperature thermal stability. With the help of first-principles calculations, great progress has been made in half-Heusler thermoelectric materials. In this review, we summarize some representative theoretical work on band structures and transport properties of HH compounds. We introduce how basic band-structure calculations are used to investigate the atomic disorder in n-type MNiSb (M = Ti, Zr, Hf) compounds and guide the band engineering to enhance TE performance in p-type FeRSb (R = V, Nb) based systems. The calculations on electrical transport properties, especially the scattering time, and lattice thermal conductivities are also demonstrated. The outlook for future research directions of first-principles calculations on HH TE materials is also discussed. PMID:29783759

Load Fatigue Performance Evaluation on Two Internal Tapered Abutment-Implant Connection Implants Under Different Screw Tightening Torques.

PubMed

Jeng, Ming-Dih; Liu, Po-Yi; Kuo, Jia-Hum; Lin, Chun-Li

2017-04-01

This study evaluates the load fatigue performance of different abutment-implant connection implant types-retaining-screw (RS) and taper integrated screwed-in (TIS) types under 3 applied torque levels based on the screw elastic limit. Three torque levels-the recommended torque (25 Ncm), 10% less, and 10% more than the ratio of recommended torque to screw elastic limits of different implants were applied to the implants to perform static and dynamic testing according to the ISO 14801 method. Removal torque loss was calculated for each group after the endurance limitation was reached (passed 5 × 10 6 cycles) in the fatigue test. The static fracture resistance results showed that the fracture resistance in the TIS-type implant significantly increased (P < .05) when the abutment screw was inserted tightly. The dynamic testing results showed that the endurance limitations for the RS-type implant were 229 N, 197 N, and 224 N and those for the TIS-type implant were 322 N, 364 N, and 376 N when the screw insertion torques were applied from low to high. The corresponding significant (P < .05) removal torque losses for the TIS-type implant were 13.2%, 5.3%, and 2.6% but no significant difference was found for the RS-type implant. This study concluded that the static fracture resistance and dynamic endurance limitation of the TIS-type implant (1-piece solid abutment) increased when torque was applied more tightly on the screw. Less torque loss was also found when increasing the screw insertion torque.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Min Ho; Rhyee, Jong-Soo, E-mail: jsrhyee@khu.ac.kr

We investigated the thermoelectric properties of PbTe/Ag{sub 2}Te bulk composites, synthesized by hand milling, mixing, and hot press sintering. From x-ray diffraction and energy dispersive x-ray spectroscopy measurements, we observed Ag{sub 2}Te phase separation in the PbTe matrix without Ag atom diffusion. In comparison with previously reported pseudo-binary (PbTe){sub 1−x}(Ag{sub 2}Te){sub x} composites, synthesized by high temperature phase separation, the PbTe/Ag{sub 2}Te bulk composites fabricated with a low temperature phase mixing process give rise to p-type conduction of carriers with significantly decreased electrical conductivity. This indicates that Ag atom diffusion in the PbTe matrix changes the sign of the Seebeckmore » coefficient to n-type and also increases the carrier concentration. Effective p-type doping with low temperature phase separation by mixing and hot press sintering can enhance the thermoelectric performance of PbTe/Ag{sub 2}Te bulk composites, which can be used as a p-type counterpart of n-type (PbTe){sub 1−x}(Ag{sub 2}Te){sub x} bulk composites.« less

Highly Uniform Carbon Nanotube Field-Effect Transistors and Medium Scale Integrated Circuits.

PubMed

Chen, Bingyan; Zhang, Panpan; Ding, Li; Han, Jie; Qiu, Song; Li, Qingwen; Zhang, Zhiyong; Peng, Lian-Mao

2016-08-10

Top-gated p-type field-effect transistors (FETs) have been fabricated in batch based on carbon nanotube (CNT) network thin films prepared from CNT solution and present high yield and highly uniform performance with small threshold voltage distribution with standard deviation of 34 mV. According to the property of FETs, various logical and arithmetical gates, shifters, and d-latch circuits were designed and demonstrated with rail-to-rail output. In particular, a 4-bit adder consisting of 140 p-type CNT FETs was demonstrated with higher packing density and lower supply voltage than other published integrated circuits based on CNT films, which indicates that CNT based integrated circuits can reach to medium scale. In addition, a 2-bit multiplier has been realized for the first time. Benefitted from the high uniformity and suitable threshold voltage of CNT FETs, all of the fabricated circuits based on CNT FETs can be driven by a single voltage as small as 2 V.

The use of FTA cards for preserving unfixed cytological material for high-throughput molecular analysis.

PubMed

Saieg, Mauro Ajaj; Geddie, William R; Boerner, Scott L; Liu, Ni; Tsao, Ming; Zhang, Tong; Kamel-Reid, Suzanne; da Cunha Santos, Gilda

2012-06-25

Novel high-throughput molecular technologies have made the collection and storage of cells and small tissue specimens a critical issue. The FTA card provides an alternative to cryopreservation for biobanking fresh unfixed cells. The current study compared the quality and integrity of the DNA obtained from 2 types of FTA cards (Classic and Elute) using 2 different extraction protocols ("Classic" and "Elute") and assessed the feasibility of performing multiplex mutational screening using fine-needle aspiration (FNA) biopsy samples. Residual material from 42 FNA biopsies was collected in the cards (21 Classic and 21 Elute cards). DNA was extracted using the Classic protocol for Classic cards and both protocols for Elute cards. Polymerase chain reaction for p53 (1.5 kilobase) and CARD11 (500 base pair) was performed to assess DNA integrity. Successful p53 amplification was achieved in 95.2% of the samples from the Classic cards and in 80.9% of the samples from the Elute cards using the Classic protocol and 28.5% using the Elute protocol (P = .001). All samples (both cards) could be amplified for CARD11. There was no significant difference in the DNA concentration or 260/280 purity ratio when the 2 types of cards were compared. Five samples were also successfully analyzed by multiplex MassARRAY spectrometry, with a mutation in KRAS found in 1 case. High molecular weight DNA was extracted from the cards in sufficient amounts and quality to perform high-throughput multiplex mutation assays. The results of the current study also suggest that FTA Classic cards preserve better DNA integrity for molecular applications compared with the FTA Elute cards. Copyright © 2012 American Cancer Society.

Correlating P-wave Velocity with the Physico-Mechanical Properties of Different Rocks

NASA Astrophysics Data System (ADS)

Khandelwal, Manoj

2013-04-01

In mining and civil engineering projects, physico-mechanical properties of the rock affect both the project design and the construction operation. Determination of various physico-mechanical properties of rocks is expensive and time consuming, and sometimes it is very difficult to get cores to perform direct tests to evaluate the rock mass. The purpose of this work is to investigate the relationships between the different physico-mechanical properties of the various rock types with the P-wave velocity. Measurement of P-wave velocity is relatively cheap, non-destructive and easy to carry out. In this study, representative rock mass samples of igneous, sedimentary, and metamorphic rocks were collected from the different locations of India to obtain an empirical relation between P-wave velocity and uniaxial compressive strength, tensile strength, punch shear, density, slake durability index, Young's modulus, Poisson's ratio, impact strength index and Schmidt hammer rebound number. A very strong correlation was found between the P-wave velocity and different physico-mechanical properties of various rock types with very high coefficients of determination. To check the sensitivity of the empirical equations, Students t test was also performed, which confirmed the validity of the proposed correlations.

Tunability of p- and n-channel TiOx thin film transistors.

PubMed

Peng, Wu-Chang; Chen, Yao-Ching; He, Ju-Liang; Ou, Sin-Liang; Horng, Ray-Hua; Wuu, Dong-Sing

2018-06-18

To acquire device-quality TiO x films usually needs high-temperature growth or additional post-thermal treatment. However, both processes make it very difficult to form the p-type TiO x even under oxygen-poor growth condition. With the aid of high energy generated by high power impulse magnetron sputtering (HIPIMS), a highly stable p-type TiO x film with good quality can be achieved. In this research, by varying the oxygen flow rate, p-type γ-TiO and n-type TiO 2 films were both prepared by HIPIMS. Furthermore, p- and n-type thin film transistors employing γ-TiO and TiO 2 as channel layers possess the field-effect carrier mobilities of 0.2 and 0.7 cm 2 /Vs, while their on/off current ratios are 1.7 × 10 4 and 2.5 × 10 5 , respectively. The first presented p-type γ-TiO TFT is a major breakthrough for fabricating the TiO x -based p-n combinational devices. Additionally, our work also confirms HIPIMS offers the possibility of growing both p- and n-type conductive oxides, significantly expanding the practical usage of this technique.

Flexible Solar Cells Using Doped Crystalline Si Film Prepared by Self-Biased Sputtering Solid Doping Source in SiCl4/H2 Microwave Plasma.

PubMed

Hsieh, Ping-Yen; Lee, Chi-Young; Tai, Nyan-Hwa

2016-02-01

We developed an innovative approach of self-biased sputtering solid doping source process to synthesize doped crystalline Si film on flexible polyimide (PI) substrate via microwave-plasma-enhanced chemical vapor deposition (MWPECVD) using SiCl4/H2 mixture. In this process, P dopants or B dopants were introduced by sputtering the solid doping target through charged-ion bombardment in situ during high-density microwave plasma deposition. A strong correlation between the number of solid doping targets and the characteristics of doped Si films was investigated in detail. The results show that both P- and B-doped crystalline Si films possessed a dense columnar structure, and the crystallinity of these structures decreased with increasing the number of solid doping targets. The films also exhibited a high growth rate (>4.0 nm/s). Under optimal conditions, the maximum conductivity and corresponding carrier concentration were, respectively, 9.48 S/cm and 1.2 × 10(20) cm(-3) for P-doped Si film and 7.83 S/cm and 1.5 × 10(20) cm(-3) for B-doped Si film. Such high values indicate that the incorporation of dopant with high doping efficiency (around 40%) into the Si films was achieved regardless of solid doping sources used. Furthermore, a flexible crystalline Si film solar cell with substrate configuration was fabricated by using the structure of PI/Mo film/n-type Si film/i-type Si film/p-type Si film/ITO film/Al grid film. The best solar cell performance was obtained with an open-circuit voltage of 0.54 V, short-circuit current density of 19.18 mA/cm(2), fill factor of 0.65, and high energy conversion of 6.75%. According to the results of bending tests, the critical radius of curvature (RC) was 12.4 mm, and the loss of efficiency was less than 1% after the cyclic bending test for 100 cycles at RC, indicating superior flexibility and bending durability. These results represent important steps toward a low-cost approach to high-performance flexible crystalline Si film-based photovoltaic devices.

Fused dithienogermolodithiophene low band gap polymers for high-performance organic solar cells without processing additives.

PubMed

Zhong, Hongliang; Li, Zhe; Deledalle, Florent; Fregoso, Elisa Collado; Shahid, Munazza; Fei, Zhuping; Nielsen, Christian B; Yaacobi-Gross, Nir; Rossbauer, Stephan; Anthopoulos, Thomas D; Durrant, James R; Heeney, Martin

2013-02-13

We report the synthesis of a novel ladder-type fused ring donor, dithienogermolodithiophene, in which two thieno[3,2-b]thiophene units are held coplanar by a bridging dialkyl germanium. Polymerization of this extended monomer with N-octylthienopyrrolodione by Stille polycondensation afforded a polymer, pDTTG-TPD, with an optical band gap of 1.75 eV combined with a high ionization potential. Bulk heterojunction solar cells based upon pDTTG-TPD:PC(71)BM blends afforded efficiencies up to 7.2% without the need for thermal annealing or processing additives.

Metal-Semiconductor Nanocomposites for High Efficiency Thermoelectric Power Generation

DTIC Science & Technology

2013-12-07

standard III–V compound semiconductor processing techniques with terbium- doped InGaAs of high terbium concentration, Journal of Vacuum Science...even lower the required temperature for strong covalent bonding. We performed the oxide bonding for this substrate transfer task (see Figure 16 for...appropriate controls for assessing ErSb:InGaSb and other nanocomposites of p-type III-V compound semiconductors and their alloys. UCSC group calculated

Smoking and anal high-risk human papillomavirus DNA loads in HIV-positive men who have sex with men.

PubMed

Wieland, Ulrike; Hellmich, Martin; Wetendorf, Janna; Potthoff, Anja; Höfler, Daniela; Swoboda, Jochen; Fuchs, Wolfgang; Brockmeyer, Norbert; Pfister, Herbert; Kreuter, Alexander

2015-10-01

HIV-positive men who have sex with men (MSM) have an increased risk for anal human papillomavirus (HPV) infection, anal high-grade intraepithelial lesions (HSIL), and anal cancer. Smoking is associated with abnormal anal cytology and with an increased risk for anal cancer. We collected 3736 intraanal swabs from 803 HIV-positive MSM who participated in an anal cancer screening program between October 2003 and August 2014. HPV prevalence, anal cytology and HPV DNA load of high-risk (HR) HPV-types 16, 18, 31 and 33 of non-smokers and smokers were compared. HPV-typing was performed by alpha-HPV genus-specific PCR and hybridization with 38 type-specific probes using a multiplex genotyping assay. In samples positive for HPV16, 18, 31, or 33, HPV DNA loads were determined by type-specific real-time PCRs and expressed as HPV DNA copies per betaglobin gene copy. At baseline, HR-HPV DNA (80.5 vs. 89.0%, p=0.001), HPV16 DNA (41.6 vs. 52.3%, p=0.003), HPV18 DNA (15.5 vs. 26.0%, p<0.001), anal dysplasia (LSIL+HSIL; 51.5 vs. 58.4%, p=0.045) and HSIL (17.2 vs. 22.7%, p=0.048) were detected more frequently in smokers compared to non-smokers. Throughout the study period 32.7% of non-smokers and 39.9% of smokers developed HSIL (p=0.011), and three smokers developed anal cancer. Considering swabs from the entire study period (median HPV load value per patient per cytology grade), smokers with normal anal cytology had significantly higher HPV16 loads (median 0.29 vs. 0.87, n=201, p=0.007) and cumulative high-risk-HPV loads (median 0.53 vs. 1.08, n=297, p=0.004) than non-smokers. Since elevated HR-HPV DNA loads are associated with an increased risk for HPV-induced anogenital cancers, HPV-infected HIV-positive MSM should be counseled to refrain from smoking. Additionally, for smokers, shorter anal cancer screening intervals than for non-smokers may be appropriate. Copyright © 2015 Elsevier GmbH. All rights reserved.

Recent advance in high manufacturing readiness level and high temperature CMOS mixed-signal integrated circuits on silicon carbide

NASA Astrophysics Data System (ADS)

Weng, M. H.; Clark, D. T.; Wright, S. N.; Gordon, D. L.; Duncan, M. A.; Kirkham, S. J.; Idris, M. I.; Chan, H. K.; Young, R. A. R.; Ramsay, E. P.; Wright, N. G.; Horsfall, A. B.

2017-05-01

A high manufacturing readiness level silicon carbide (SiC) CMOS technology is presented. The unique process flow enables the monolithic integration of pMOS and nMOS transistors with passive circuit elements capable of operation at temperatures of 300 °C and beyond. Critical to this functionality is the behaviour of the gate dielectric and data for high temperature capacitance-voltage measurements are reported for SiO2/4H-SiC (n and p type) MOS structures. In addition, a summary of the long term reliability for a range of structures including contact chains to both n-type and p-type SiC, as well as simple logic circuits is presented, showing function after 2000 h at 300 °C. Circuit data is also presented for the performance of digital logic devices, a 4 to 1 analogue multiplexer and a configurable timer operating over a wide temperature range. A high temperature micro-oven system has been utilised to enable the high temperature testing and stressing of units assembled in ceramic dual in line packages, including a high temperature small form-factor SiC based bridge leg power module prototype, operated for over 1000 h at 300 °C. The data presented show that SiC CMOS is a key enabling technology in high temperature integrated circuit design. In particular it provides the ability to realise sensor interface circuits capable of operating above 300 °C, accommodate shifts in key parameters enabling deployment in applications including automotive, aerospace and deep well drilling.

p × n-Type Transverse Thermoelectrics: A Novel Type of Thermal Management Material

NASA Astrophysics Data System (ADS)

Tang, Yang; Cui, Boya; Zhou, Chuanle; Grayson, Matthew

2015-06-01

In this paper we review the recently identified p × n-type transverse thermoelectrics and study the thermoelectric properties of the proposed candidate materials. Anisotropic electron and hole conductivity arise from either an artificially engineered band structure or from appropriately anisotropic crystals, and result in orthogonal p-type and n-type directional Seebeck coefficients, inducing a non-zero off-diagonal transverse Seebeck coefficient with appropriately oriented currents. Such materials have potential for new applications of thermoelectric materials in transverse Peltier cooling and transverse thermal energy harvesting. In this paper we review general transverse thermoelectric phenomena to identify advantages of p × n-type transverse thermoelectrics compared with previously studied transverse thermoelectric phenomena. An intuitive overview of the band structure of one such p × n-material, the InAs/GaSb type-II superlattice, is introduced, and the plot of thermoelectric performance as a function of superlattice structure is calculated, as an example of how band structures can be optimized for the best transverse thermoelectric performance.

MOCVD Growth and Characterization of n-type Zinc Oxide Thin Films

NASA Astrophysics Data System (ADS)

Ben-Yaacov, Tammy

In the past decade, there has been widespread effort in the development of zinc oxide as a II-V1 semiconductor material. ZnO has potential advantages in optoelectronip device applications due to its unique electrical and optical properties. What stands out among these properties is its wide direct bandgap of 3.37 eV and its high electrical conductivity and transparency in the visible and near-UV regions of the spectrum. ZnO can be grown heteroepitaxially on GaN under near lattice-matched conditions and homoepitaxially as well, as high-quality bulk ZnO substrates are commercially available. This dissertation focuses on the development of the growth of high-quality, single crystal n-type ZnO films, control of n-type conductivity, as well as its application as a transparent contact material in GaN-based devices. The first part of this dissertation is an extensive heteroepitaxial and homoepitaxial growth study presenting the properties of ZnO(0001) layers grown on GaN(0001) templates and ZnO(0001) substrates. We show that deposition on GaN requires a two-step growth technique involving the growth of a low temperature nucleation layer before growing a high temperature epitaxial layer in order to obtain smooth ZnO films with excellent crystal quality and step-flow surface morphology. We obtained homoepitaxial ZnO(0001) films of structural quality and surface morphology that is comparable to the as-received substrates, and showed that a high growth temperature (≥1000°C) is needed in order to achieve step-flow growth mode. We performed n-type doping experiments, and established the conditions for which Indium effectively controls the n-type conductivity of ZnO films grown on GaN(0001) templates. A peak carrier concentration of 3.22x 10 19cm-3 and minimum sheet resistance of 97 O/square was achieved, while simultaneously maintaining good morphology and crystal quality. Finally, we present In-doped ZnO films implemented as p-contacts for GaN-based solar cells and LEDs, and we investigate the n-ZnO/p-GaN interface. We show that ZnO has potential as an effective p-contact for these devices, and determine properties that still need improvement in order for ZnO to compete with other contact materials. We also compare the device performance to metal-contacted devices. In summary, this thesis describes the growth of ZnO(0001) films by MOCVD, the progress in developing ZnO material with excellent surface morphology, high crystal quality, and controllable n-type doping, as well as its application to GaN-based optoelectronic devices as a p-contact material.

Effect of low vitamin A diets with high-moisture or dry corn on marbling and adipose tissue fatty acid composition of beef steers.

PubMed

Gorocica-Buenfil, M A; Fluharty, F L; Bohn, T; Schwartz, S J; Loerch, S C

2007-12-01

Angus-cross steers (n = 165; 295 +/- 16 kg of BW) were used evaluate the effect of low vitamin A diets with high-moisture corn (HMC) or dry corn (DC) on marbling and fatty acid composition. Steers were allotted to 24 pens (7 steers/pen), such that each pen had the same average initial BW. Treatments were randomly allotted to the pens. The experiment had a completely randomized design, with a 2 x 2 factorial arrangement of treatments: low vitamin A (Lo, no supplemental vitamin A) and HMC (LoHMC); LoDC; high vitamin A (Hi, supplemented with 2,200 IU of vitamin A/kg of DM) and HMC (HiHMC); and HiDC. Diets contained 76% corn, 10% corn silage, 11% protein supplement, and 3% soybean oil (DM basis). Samples of feed ingredients were collected for carotenoid analysis. Blood samples were collected for serum retinol determination. Steers were slaughtered after 145 d on feed. Carcass characteristics and LM composition were determined. Samples from the s.c. fat depot were analyzed for fatty acid composition. High-moisture corn had a greater vitamin A content, based on its carotenoid content, than DC (614 vs. 366 IU/kg of DM, P < 0.01). No vitamin A x corn type interactions were detected for feedlot performance, carcass characteristics, or serum, s.c. fat, or liver retinol concentration. Average daily gain, DMI, and G:F were not affected by vitamin A (P > 0.05). Marbling score and USDA quality grade were greater (P < 0.05) in Lo vs. Hi steers. Hot carcass weight, backfat, and yield grade were not affected by the treatments (P > 0.05). Vitamin A and corn type did not affect LM composition (DM, ash, CP, or ether-extractable fat, P > 0.05). Vitamin A supplementation increased (P < 0.06) serum retinol on d 112 and 145 and increased (P < 0.01) liver retinol at slaughter (Lo = 38.7 vs. Hi = 102.9 mug/g). The s.c. fat retinol concentrations were less (P < 0.01) for Lo (0.8 mug/g) than for Hi (1.4 mug/g) at slaughter. Cell diameter of adipocytes in the i.m. depot was not affected by dietary vitamin A (P > 0.05). A vitamin A x corn type interaction was observed (P < 0.05) for the s.c. fat cellularity. Feeding HMC increased the number of cells per square millimeter when Lo diets were fed (LoHMC = 128 vs. LoDC = 100 cells/mm(2), P < 0.05), but not when Hi diets were fed (HiHMC = 109 vs. HiDC = 111 cells/mm(2), P > 0.05). The CLA content of adipose tissue was not affected by the treatments. Regardless of the corn type used, feeding low vitamin A diets for 145 d to Angus-cross steers increased marbling and quality grade without affecting yield grade, animal health, or performance.

Two-dimensional n -InSe/p -GeSe(SnS) van der Waals heterojunctions: High carrier mobility and broadband performance

NASA Astrophysics Data System (ADS)

Xia, Cong-xin; Du, Juan; Huang, Xiao-wei; Xiao, Wen-bo; Xiong, Wen-qi; Wang, Tian-xing; Wei, Zhong-ming; Jia, Yu; Shi, Jun-jie; Li, Jing-bo

2018-03-01

Recently, constructing van der Waals (vdW) heterojunctions by stacking different two-dimensional (2D) materials has been considered to be effective strategy to obtain the desired properties. Here, through first-principles calculations, we find theoretically that the 2D n -InSe/p -GeSe(SnS) vdW heterojunctions are the direct-band-gap semiconductor with typical type-II band alignment, facilitating the effective separation of photogenerated electron and hole pairs. Moreover, they possess the high optical absorption strength (˜105 ), broad spectrum width, and excellent carrier mobility (˜103c m2V-1s-1 ). Interestingly, under the influences of the interlayer coupling and external electric field, the characteristics of type-II band alignment is robust, while the band-gap values and band offset are tunable. These results indicate that 2D n -InSe/p -GeSe(SnS) heterojunctions possess excellent optoelectronic and transport properties, and thus can become good candidates for next-generation optoelectronic nanodevices.

High-Intensity Interval Training as a Tool for Counteracting Dyslipidemia in Women.

PubMed

Alvarez, Cristian; Ramirez-Campillo, Rodrigo; Martinez-Salazar, Cristian; Castillo, Angélica; Gallardo, Francisco; Ciolac, Emmanuel Gomes

2018-05-01

Sedentary overweight or obese adult (age<60 years) women, allocated in type 2 diabetes mellitus (T2DM, n =13), dyslipidemia alone (DYS, n =12), dyslipidemia associated with hyperglycaemia (DYSHG, N=12), or healthy control (CON, n =10) groups, had their lipid, glucose, blood pressure, endurance performance, and anthropometry variables assessed before and after 16 weeks of a thrice-weekly high-intensity interval training (HIIT) program. Triglycerides reduced significantly ( P <0.05) in all groups, and high-density lipoprotein increased ( P <0.01) in T2DM, DYS and DYSHG; however, low-density lipoprotein reduced ( P <0.05) only in DYSHG, and total cholesterol reduced ( P <0.01) only in DYS and DYSHG. Fasting glucose reduced ( P <0.05) significantly in T2DM, DYS and DYSHG, but with higher decreases in T2DM and DYSHG. Blood pressure, endurance performance and body composition improved ( P <0.05) in all groups. The HIIT program was effective for restoring lipid profile of DYS and DYSHG, and fasting glucose of DYSHG to levels similar to those of CON, with a weekly time commitment 25% to 56% lower than the minimum recommended in current exercise guidelines. These findings suggest that HIIT may be a time-efficient intervention for counteracting dyslipidemia. © Georg Thieme Verlag KG Stuttgart · New York.

Electrode effects on temporal changes in electrolyte pH and redox potential for water treatment

PubMed Central

Ciblak, Ali; Mao, Xuhui; Padilla, Ingrid; Vesper, Dorothy; Alshawabkeh, Iyad; Alshawabkeh, Akram N.

2012-01-01

The performance of electrochemical remediation methods could be optimized by controlling the physicochemical conditions of the electrochemical redox system. The effects of anode type (reactive or inert), current density and electrolyte composition on the temporal changes in pH and redox potential of the electrolyte were evaluated in divided and mixed electrolytes. Two types of electrodes were used: iron as a reactive electrode and mixed metal oxide coated titanium (MMO) as an inert electrode. Electric currents of 15, 30, 45 and 60 mA (37.5 mA L−1, 75 mA L−1, 112.5 mA L−1 and 150 mA L−1) were applied. Solutions of NaCl, Na2SO4 and NaHCO3 were selected to mimic different wastewater or groundwater composition. Iron anodes resulted in highly reducing electrolyte conditions compared to inert anodes. Electrolyte pH was dependent on electrode type, electrolyte composition and current density. The pH of mixed-electrolyte was stable when MMO electrodes were used. When iron electrodes were used, the pH of electrolyte with relatively low current density (37.5 mA L−1) did not show significant changes but the pH increased sharply for relatively high current density (150 mA L−1). Sulfate solution showed more basic and relatively more reducing electrolyte condition compared to bicarbonate and chloride solution. The study shows that a highly reducing environment could be achieved using iron anodes in divided or mixed electrolytes and the pH and redox potential could be optimized by using appropriate current and polarity reversal. PMID:22416866

[Role of hemoglobin affinity to oxygen in adaptation to hypoxemia].

PubMed

Kwasiborski, Przemysław Jerzy; Kowalczyk, Paweł; Zieliński, Jakub; Przybylski, Jacek; Cwetsch, Andrzej

2010-04-01

One of the basic mechanisms of adapting to hypoxemia is a decrease in the affinity of hemoglobin for oxygen. This process occurs mainly due to the increased synthesis of 2,3-diphosphoglycerate (2,3-DPG) in the erythrocytes, as well as through the Bohr effect. Hemoglobin with decreased affinity for oxygen increases the oxygenation of tissues, because it gives up oxygen more easily during microcirculation. In foetal circulation, however, at a partial oxygen pressure (pO2) of 25 mmHg in the umbilical vein, the oxygen carrier is type F hemoglobin which has a high oxygen affinity. The commonly accepted role for hemoglobin F is limited to facilitating diffusion through the placenta. Is fetal life the only moment when haemoglobin F is useful? THE AIM OF STUDY was to create a mathematical model, which would answer the question at what conditions an increase, rather than a decrease, in haemoglobin oxygen affinity is of benefit to the body. Using the kinetics of dissociation of oxygen from hemoglobin described by the Hill equation as the basis for further discussion, we created a mathematical model describing the pO2 value in the microcirculatory system and its dependence on arterial blood pO2. The calculations were performed for hemoglobin with low oxygen affinity (adult type) and high-affinity hemoglobin (fetal type). The modelling took into account both physiological and pathological ranges of acid-base equilibrium and tissue oxygen extraction parameters. It was shown that for the physiological range of acid-base equilibrium and the resting level of tissue oxygen extraction parameters, with an arterial blood pO2 of 26.8 mmHg, the higher-affinity hemoglobin becomes the more effective oxygen carrier. It was also demonstrated that the arterial blood pO2, below which the high-affinity hemoglobin becomes the more effective carrier, is dependent on blood pH and the difference between the arterial and venous oxygen saturation levels. Simulations performed for the pathological states showed that acidosis and increased tissue oxygen demand lead to a broadened arterial blood pO2 range, in which the high-affinity hemoglobin is more efficient. Contrary to the widely held view that the only response to hypoxemia is a decrease in haemoglobin oxygen affinity, it was shown that under extreme hypoxemic conditions, an increased haemoglobin oxygen affinity improves the oxygenation of tissues. It was also shown that the dominance of hemoglobin with a high oxygen affinity rapidly exceeds hemoglobin with low oxygen affinity in the case of acidosis with its accompanying high tissue oxygen extraction. In cases of extreme disruptions of the acid-base equilibrium, the dominance of high-oxygen-affinity hemoglobin spans over the entire possible range of pO2 in arterial blood.

MASH TL-4 evaluation of the TxDOT type C2P bridge rail.

DOT National Transportation Integrated Search

2017-02-01

The objective of this research was to evaluate the impact performance of the Texas Department of Transportation (TxDOT) Type C2P Bridge Rail according to the safety-performance evaluation guidelines included in the American Association of State Highw...

Effects of dietary coarsely ground corn and litter type on broiler live performance, litter characteristics, gastrointestinal tract development, apparent ileal digestibility of energy and nitrogen, and intestinal morphology.

PubMed

Xu, Y; Stark, C R; Ferket, P R; Williams, C M; Auttawong, S; Brake, J

2015-03-01

The objectives of this study were to evaluate the effects of the dietary inclusion of 2 coarsely ground corn (CC) levels (0 or 50%) in diets of broilers reared on 2 litter types (new wood shavings or used litter) on live performance, litter characteristics, gastrointestinal tract (GIT) development, apparent ileal digestibility (AID) of energy and nitrogen (N), and intestinal morphology. No interaction effects between CC level and litter type were observed on live performance. No litter effect was observed on live performance. Dietary inclusion of 50% CC increased BW at 35 d (P<0.01) and improved cumulative feed conversion ratio (FCR) at 35 and 49 d of age (P<0.01). The 50% CC treatment increased absolute and relative gizzard weight (P<0.01) and decreased jejunum unit weight (g/cm) (P<0.01). The new litter treatment (litter N) increased absolute and relative proventriculus weight (P<0.05) but did not affect gizzard weight. An interaction effect between CC level and litter type was observed for litter N, where the 50% CC treatment reduced litter N regardless of litter type (P<0.01), but litter N was reduced by new litter only among birds fed 0% CC (P<0.05). The 50% CC inclusion increased litter pH (P<0.05) and improved the AID of energy and N by 6.8% (P<0.01) and 3.5% (P<0.05), respectively. The 50% CC treatment increased jejunum villi tip width (P<0.05) and villi surface area (P<0.01), and decreased the muscularis layer thickness (P<0.01), whereas new litter increased jejunum villi and ileum villi height (P<0.05), jejunum villi surface area (P<0.01), and the ratio of jejunum villi height to crypt depth (P<0.01). This study showed that birds fed pelleted and screened diets containing 50% CC exhibited improved BW, FCR, and AID of energy and N, in conjunction with altered morphology of the GIT and intestinal mucosa. Litter type affected some GIT traits and functions but did not affect live performance. © 2015 Poultry Science Association Inc.

High-Fat-Diet Intake Enhances Cerebral Amyloid Angiopathy and Cognitive Impairment in a Mouse Model of Alzheimer's Disease, Independently of Metabolic Disorders.

PubMed

Lin, Bowen; Hasegawa, Yu; Takane, Koki; Koibuchi, Nobutaka; Cao, Cheng; Kim-Mitsuyama, Shokei

2016-06-13

The high-fat Western diet is postulated to be associated with the onset and progression of Alzheimer's disease (AD). However, the role of high-fat-diet consumption in AD pathology is unknown. This study was undertaken to examine the role of high-fat-diet intake in AD. 5XFAD mice, a useful mouse model of AD, and control wild-type mice were fed (1) high-fat diet or (2) control diet for 10 weeks. The effects on cerebral AD pathology, cognitive function, and metabolic parameters were compared between each group of mice. High-fat diet significantly enhanced cerebrovascular β-amyloid (Aβ) deposition (P<0.05) and impaired cognitive function (P<0.05) in 5XFAD mice, but not in wild-type mice. High-fat diet enhanced hippocampal oxidative stress (P<0.05) and NADPH oxidase subunits, gp91(phox) (P<0.01) and p22(phox) (P<0.01) in 5XFAD mice, but not in wild-type mice. Furthermore, high-fat diet reduced cerebral occludin (P<0.05) in 5XFAD mice, but not in wild-type mice. Thus, 5XFAD mice exhibited greater susceptibility to high-fat diet than wild-type mice regarding cerebrovascular injury and cognitive impairment. On the other hand, 5XFAD mice fed high-fat diet exhibited much less increase in body weight, white adipose tissue weight, and adipocyte size than their wild-type counterparts. High-fat diet significantly impaired glucose tolerance in wild-type mice but not in 5XFAD mice. Thus, 5XFAD mice had much less susceptibility to high-fat-diet-induced metabolic disorders than wild-type mice. High-fat diet, independently of metabolic disorders, significantly promotes the progression of AD-like pathology through enhancement of cerebral amyloid angiopathy and oxidative stress. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Changes in Bone Alkaline Phosphatase and Procollagen Type-1 C-Peptide after Static and Dynamic Exercises

ERIC Educational Resources Information Center

Kubo, Keitaro; Yuki, Kazuhito; Ikebukuro, Toshihiro

2012-01-01

We investigated the effects of two types of nonweight-bearing exercise on changes in bone-specific alkaline phosphatase (BAP) and pro-collagen type 1 C-peptide (P1P). BAP is a specific marker of bone synthesis, whereas P1P reflects synthesis of type 1 collagen in other organs as well as bone. Eight participants performed static and dynamic…

Novel, high-intensity exercise prescription improves muscle mass, mitochondrial function, and physical capacity in individuals with Parkinson's disease

PubMed Central

Kelly, Neil A.; Ford, Matthew P.; Standaert, David G.; Watts, Ray L.; Bickel, C. Scott; Moellering, Douglas R.; Tuggle, S. Craig; Williams, Jeri Y.; Lieb, Laura; Windham, Samuel T.

2014-01-01

We conducted, in persons with Parkinson's disease (PD), a thorough assessment of neuromotor function and performance in conjunction with phenotypic analyses of skeletal muscle tissue, and further tested the adaptability of PD muscle to high-intensity exercise training. Fifteen participants with PD (Hoehn and Yahr stage 2–3) completed 16 wk of high-intensity exercise training designed to simultaneously challenge strength, power, endurance, balance, and mobility function. Skeletal muscle adaptations (P < 0.05) to exercise training in PD included myofiber hypertrophy (type I: +14%, type II: +36%), shift to less fatigable myofiber type profile, and increased mitochondrial complex activity in both subsarcolemmal and intermyofibrillar fractions (I: +45–56%, IV: +39–54%). These adaptations were accompanied by a host of functional and clinical improvements (P < 0.05): total body strength (+30–56%); leg power (+42%); single leg balance (+34%); sit-to-stand motor unit activation requirement (−30%); 6-min walk (+43 m), Parkinson's Disease Quality of Life Scale (PDQ-39, −7.8pts); Unified Parkinson's Disease Rating Scale (UPDRS) total (−5.7 pts) and motor (−2.7 pts); and fatigue severity (−17%). Additionally, PD subjects in the pretraining state were compared with a group of matched, non-PD controls (CON; did not exercise). A combined assessment of muscle tissue phenotype and neuromuscular function revealed a higher distribution and larger cross-sectional area of type I myofibers and greater type II myofiber size heterogeneity in PD vs. CON (P < 0.05). In conclusion, persons with moderately advanced PD adapt to high-intensity exercise training with favorable changes in skeletal muscle at the cellular and subcellular levels that are associated with improvements in motor function, physical capacity, and fatigue perception. PMID:24408997

Radiation damage in high voltage silicon solar cells

NASA Technical Reports Server (NTRS)

Weinberg, I.; Brandhorst, H., Jr.; Swartz, C. K.; Weizer, V. G.

1980-01-01

Three high open-circuit voltage cell designs based on 0.1 ohm-cm p-type silicon were irradiated with 1 MeV electrons and their performance determined to fluences as high as 10 to the 15th power/sq cm. Of the three cell designs, radiation induced degradation was greatest in the high-low emitter (HLE cell). The diffused and ion implanted cells degraded approximately equally but less than the HLE cell. Degradation was greatest in an HLE cell exposed to X-rays before electron irradiation. The cell regions controlling both short-circuit current and open-circuit voltage degradation were defined in all three cell types. An increase in front surface recombination velocity accompanied time dependent degradation of an HLE cell after X-irradiation. It was speculated that this was indirectly due to a decrease in positive charge at the silicon-oxide interface. Modifications aimed at reducing radiation induced degradation are proposed for all three cell types.

Effectiveness of an intensive multidisciplinary headache treatment program.

PubMed

Gunreben-Stempfle, Birgit; Griessinger, Norbert; Lang, Eberhard; Muehlhans, Barbara; Sittl, Reinhard; Ulrich, Kathrin

2009-07-01

To investigate if the effectiveness of a 96-hour multidisciplinary headache treatment program exceeds the effectiveness of a 20-hour program and primary care. When dealing with chronic back pain, low-intensity multidisciplinary treatment yields no significantly better results than standard care and monodisciplinary therapy; however, high-intensity treatment does. For multidisciplinary headache treatment, such comparisons are not yet available. In a previous study undertaken by our Pain Center, the outcome of a minimal multidisciplinary intervention model (20-hour) did not exceed primary care. Forty-two patients suffering from frequent headaches (20 +/- 9 headache days/month; range: 8-30) were treated and evaluated in a 96-hour group program. The results were compared with the outcomes of the previous study. Subjects who had undergone either the 20-hour multidisciplinary program or the primary care were used as historical control groups. A significant reduction in migraine days (P < .001), tension-type headache days (P < .001), frequency of migraine attacks (P = .004), and depression score (P < .001) was seen at the follow-up after 22 (+/-2) weeks. Comparing the intensive multidisciplinary program with primary care, repeated measures ANOVAs revealed significant time x group interactions for migraine days (P = .020), tension-type headache days (P = .016), and frequency of migraine attacks (P = .016). In comparison with the 20-hour multidisciplinary program, the 96-hour program showed significantly better effects only in the reduction of migraine days (P = .037) and depression score (P = .003). The responder-rates (> or =50% improvement) in the 96-hour program were significantly higher than in the 20-hour program (migraine days, P = .008; tension-type headache days, P = .044) and primary care (migraine days, P = .007; tension-type headache days, P = .003; tension-type headache intensity, P = .037). The effect sizes were small to medium in the 96-hour program. Particularly with the reduction of migraine symptomatology, the 96-hour program performed better than the 20-hour program, which produced only negligible or small effects. Intensive multidisciplinary headache treatment is highly effective for patients with chronic headaches. Furthermore, migraine symptomatology responds especially well to this intensive treatment program, whereas effects on tension-type headaches were realized by both multidisciplinary programs. Randomized controlled trials and subgroup analysis are needed to find out if these results can be replicated and which patient characteristics allow for sufficient improvements for headache sufferers even with less complex treatment.

Lower limb kinematics of male and female soccer players during a self-selected cutting maneuver: Effects of prolonged activity.

PubMed

McGovern, Andrew; Dude, Christopher; Munkley, Daniel; Martin, Thomas; Wallace, David; Feinn, Richard; Dione, Donald; Garbalosa, Juan C

2015-12-01

Despite the recent emphasis on injury prevention, anterior cruciate ligament (ACL) injury rates remain high. This study aimed to ascertain the effects of prolonged activity on lower limb kinematics during a self-selected cutting maneuver. Angular kinematics were recorded during an agility test performed until the completion time was greater than the mean plus one SD of baseline trials. Cut type was identified and the hip and knee angles at 33 ms post heel strike were determined. A linear mixed effects model assessed the effects of cut type, gender, and activity status on the hip and knee angles. Males performed sidestep cuts more frequently than females. Females increased the incidence of sidestep cuts after prolonged activity. At the hip, a gender-cut type interaction existed for the transverse (p=0.001) and sagittal (p=0.11) planes. Females showed more internal rotation during sidestep and more external rotation and less flexion during crossover cuts. For the frontal plane, a gender-activity status interaction (p = 0.032) was due to no change within females but greater hip adduction during prolonged activity within males. With prolonged activity, both genders displayed less hip (p=0.29) and knee (p=0.009) flexion and more knee (p=0.001) adduction. Females displayed less hip and knee flexion than men (p=0.001). Sidestep may be more risky than crossover cuts. Both genders place themselves in at-risk postures with prolonged activity due to less hip and knee flexion. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of two-step Mg doping in p-GaN on efficiency characteristics of InGaN blue light-emitting diodes without AlGaN electron-blocking layers

NASA Astrophysics Data System (ADS)

Ryu, Han-Youl; Lee, Jong-Moo

2013-05-01

A light-emitting diode (LED) structure containing p-type GaN layers with two-step Mg doping profiles is proposed to achieve high-efficiency performance in InGaN-based blue LEDs without any AlGaN electron-blocking-layer structures. Photoluminescence and electroluminescence (EL) measurement results show that, as the hole concentration in the p-GaN interlayer between active region and the p-GaN layer increases, defect-related nonradiative recombination increases, while the electron current leakage decreases. Under a certain hole-concentration condition in the p-GaN interlayer, the electron leakage and active region degradation are optimized so that high EL efficiency can be achieved. The measured efficiency characteristics are analyzed and interpreted using numerical simulations.

Processing of n+/p-/p+ strip detectors with atomic layer deposition (ALD) grown Al2O3 field insulator on magnetic Czochralski silicon (MCz-si) substrates

NASA Astrophysics Data System (ADS)

Härkönen, J.; Tuovinen, E.; Luukka, P.; Gädda, A.; Mäenpää, T.; Tuominen, E.; Arsenovich, T.; Junkes, A.; Wu, X.; Li, Z.

2016-08-01

Detectors manufactured on p-type silicon material are known to have significant advantages in very harsh radiation environment over n-type detectors, traditionally used in High Energy Physics experiments for particle tracking. In p-type (n+ segmentation on p substrate) position-sensitive strip detectors, however, the fixed oxide charge in the silicon dioxide is positive and, thus, causes electron accumulation at the Si/SiO2 interface. As a result, unless appropriate interstrip isolation is applied, the n-type strips are short-circuited. Widely adopted methods to terminate surface electron accumulation are segmented p-stop or p-spray field implantations. A different approach to overcome the near-surface electron accumulation at the interface of silicon dioxide and p-type silicon is to deposit a thin film field insulator with negative oxide charge. We have processed silicon strip detectors on p-type Magnetic Czochralski silicon (MCz-Si) substrates with aluminum oxide (Al2O3) thin film insulator, grown with Atomic Layer Deposition (ALD) method. The electrical characterization by current-voltage and capacitance-voltage measurement shows reliable performance of the aluminum oxide. The final proof of concept was obtained at the test beam with 200 GeV/c muons. For the non-irradiated detector the charge collection efficiency (CCE) was nearly 100% with a signal-to-noise ratio (S/N) of about 40, whereas for the 2×1015 neq/cm2 proton irradiated detector the CCE was 35%, when the sensor was biased at 500 V. These results are comparable with the results from p-type detectors with the p-spray and p-stop interstrip isolation techniques. In addition, interestingly, when the aluminum oxide was irradiated with Co-60 gamma-rays, an accumulation of negative fixed oxide charge in the oxide was observed.

Interfacing of high temperature Z-meter setup using python

NASA Astrophysics Data System (ADS)

Patel, Ashutosh; Sisodia, Shashank; Pandey, Sudhir K.

2017-05-01

In this work, we interface high temperature Z-meter setup to automize the whole measurement process. A program is built on open source programming language `Python' which convert the manual measurement process into fully automated process without any cost addition. Using this program, simultaneous measurement of Seebeck coefficient (α), thermal conductivity (κ) and electrical resistivity (ρ), are performed and using all three, figure-of-merit (ZT) is calculated. Developed program is verified by performing measurement over p-type Bi0.36Sb1.45Te3 sample and the data obtained are found to be in good agreement with the reported data.

Blocked versus randomized presentation modes differentially modulate feedback-related negativity and P3b amplitudes

PubMed Central

Pfabigan, Daniela M.; Zeiler, Michael; Lamm, Claus; Sailer, Uta

2014-01-01

Objective Electrophysiological studies on feedback processing typically use a wide range of feedback stimuli which might not always be comparable. The current study investigated whether two indicators of feedback processing – feedback-related negativity (FRN) and P3b – differ for feedback stimuli with explicit (facial expressions) or assigned valence information (symbols). In addition, we assessed whether presenting feedback in either a trial-by-trial or a block-wise fashion affected these ERPs. Methods EEG was recorded in three experiments while participants performed a time estimation task and received two different types of performance feedback. Results Only P3b amplitudes varied consistently in response to feedback type for both presentation types. Moreover, the blocked feedback type presentation yielded more distinct FRN peaks, higher effect sizes, and a significant relation between FRN amplitudes and behavioral task performance measures. Conclusion Both stimulus type and presentation mode may provoke systematic changes in feedback-related ERPs. The current findings point at important potential confounds that need to be controlled for when designing FRN or P3b studies. Significance Studies investigating P3b amplitudes using mixed types of stimuli have to be interpreted with caution. Furthermore, we suggest implementing a blocked presentation format when presenting different feedback types within the same experiment. PMID:24144779

Introduction of Interfacial Charges to Black Phosphorus for a Family of Planar Devices

NASA Astrophysics Data System (ADS)

Bao, Lihong; Wang, Guocai; Du, Shixuan; Pantelides, Sokrates; Gao, Hong-Jun

As a young member in the family of two dimensional materials, black phosphorus (BP) has attracted great attention since its discovery due to its high hole mobility and a sizable and tunable bandgap, which meets the basic requirements for logic circuits applications. Naturally, for realization of complementary logic operation, the challenge lies in how to control the conduction type in BP FETs, i.e., the dominant carrier types, holes (p-type) or electrons (n-type). However, the absence of reliable substitutional doping techniques makes this task a great challenge. Introducing interfacial charges into 2D materials has been proven to be a successfulway to control conduction. In this work, we, for the first time, demonstrate that capping a thin BP layer with a layer of cross-linked PMMA can modify the conductivity type of the BP by a surface charge transfer process, converting a BP layer dominated by hole conduction in the absence of an external electric field (p-type) to one dominated by electron conduction (n-type). Combining BP films capped by cross-linked PMMA with standard BP, a familyof planar devices can be created, including BP gated diodes and bidirectional recitifiers (rectification ratio >102) and BP logic inverter (gain¡«0.75) which are capable of performing current rectification, switching, and signal inversion operations. The device performance demonstrated here suggests a promising route for developing 2D-based electronics.

Image processing system design for microcantilever-based optical readout infrared arrays

NASA Astrophysics Data System (ADS)

Tong, Qiang; Dong, Liquan; Zhao, Yuejin; Gong, Cheng; Liu, Xiaohua; Yu, Xiaomei; Yang, Lei; Liu, Weiyu

2012-12-01

Compared with the traditional infrared imaging technology, the new type of optical-readout uncooled infrared imaging technology based on MEMS has many advantages, such as low cost, small size, producing simple. In addition, the theory proves that the technology's high thermal detection sensitivity. So it has a very broad application prospects in the field of high performance infrared detection. The paper mainly focuses on an image capturing and processing system in the new type of optical-readout uncooled infrared imaging technology based on MEMS. The image capturing and processing system consists of software and hardware. We build our image processing core hardware platform based on TI's high performance DSP chip which is the TMS320DM642, and then design our image capturing board based on the MT9P031. MT9P031 is Micron's company high frame rate, low power consumption CMOS chip. Last we use Intel's company network transceiver devices-LXT971A to design the network output board. The software system is built on the real-time operating system DSP/BIOS. We design our video capture driver program based on TI's class-mini driver and network output program based on the NDK kit for image capturing and processing and transmitting. The experiment shows that the system has the advantages of high capturing resolution and fast processing speed. The speed of the network transmission is up to 100Mbps.

Electrotransformation of highly DNA-restrictive corynebacteria with synthetic DNA.

PubMed

Ankri, S; Reyes, O; Leblon, G

1996-01-01

Highly DNA-restrictive Corynebacteria can be transformed with DNA made in vitro by PCR amplification of a sequence that contains the replication origin of pBL1, a plasmid common to many Corynebacteria. In all strains examined, the transformation efficiencies of PCR-synthetized DNA equal or improve the performances of heterologous DNA extracted from wild-type and dam(-)-dcm-strains of Escherichia coli. The transformation efficiencies obtained with PCR-made DNA may be high enough to permit its general application to experiments of gene integration.

Thread-Like CMOS Logic Circuits Enabled by Reel-Processed Single-Walled Carbon Nanotube Transistors via Selective Doping.

PubMed

Heo, Jae Sang; Kim, Taehoon; Ban, Seok-Gyu; Kim, Daesik; Lee, Jun Ho; Jur, Jesse S; Kim, Myung-Gil; Kim, Yong-Hoon; Hong, Yongtaek; Park, Sung Kyu

2017-08-01

The realization of large-area electronics with full integration of 1D thread-like devices may open up a new era for ultraflexible and human adaptable electronic systems because of their potential advantages in demonstrating scalable complex circuitry by a simply integrated weaving technology. More importantly, the thread-like fiber electronic devices can be achieved using a simple reel-to-reel process, which is strongly required for low-cost and scalable manufacturing technology. Here, high-performance reel-processed complementary metal-oxide-semiconductor (CMOS) integrated circuits are reported on 1D fiber substrates by using selectively chemical-doped single-walled carbon nanotube (SWCNT) transistors. With the introduction of selective n-type doping and a nonrelief photochemical patterning process, p- and n-type SWCNT transistors are successfully implemented on cylindrical fiber substrates under air ambient, enabling high-performance and reliable thread-like CMOS inverter circuits. In addition, it is noteworthy that the optimized reel-coating process can facilitate improvement in the arrangement of SWCNTs, building uniformly well-aligned SWCNT channels, and enhancement of the electrical performance of the devices. The p- and n-type SWCNT transistors exhibit field-effect mobility of 4.03 and 2.15 cm 2 V -1 s -1 , respectively, with relatively narrow distribution. Moreover, the SWCNT CMOS inverter circuits demonstrate a gain of 6.76 and relatively good dynamic operation at a supply voltage of 5.0 V. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Type-inversion as a working mechanism of high voltage MAPbBr3(Cl)-based halide perovskite solar cells.

PubMed

Kedem, Nir; Kulbak, Michael; Brenner, Thomas M; Hodes, Gary; Cahen, David

2017-02-22

Using several metals with different work functions as solar cell back contact we identify majority carrier type inversion in methylammonium lead bromide (MAPbBr3, without intentional doping) as the basis for the formation of a p-n junction. MAPbBr 3 films deposited on TiO 2 are slightly n-type, whereas in a full device they are strongly p-type. The charge transfer between the metal electrode and the halide perovskite (HaP) film is shown to determine the dominant charge carrier type of the HaP and, thus, also of the final cells. Usage of Pt, Au and Pb as metal electrodes shows the effects of metal work function on minority carrier diffusion length and majority carrier concentration in the HaP, as well as on built-in voltage, band bending, and open circuit voltage (V OC ) within a solar cell. V OC > 1.5 V is demonstrated. The higher the metal WF, the higher the carrier concentration induced in the HaP, as indicated by a narrower space charge region and a smaller minority carrier diffusion length. From the analysis of bias-dependent electron beam-induced currents, the HaP carrier concentrations are estimated to be ∼ 1 × 10 17 cm -3 with Au and 2-3 × 10 18 cm -3 with Pt. A model in which type-inversion stretches across the entire film width implies formation of the p-n junction away from the interface, near the back-contact metal electrode. This work highlights the importance of the contact metal on device performance in that contact engineering can also serve to control the carrier concentration in HaP.

Factors that affect Pickering emulsions stabilized by graphene oxide.

PubMed

He, Yongqiang; Wu, Fei; Sun, Xiying; Li, Ruqiang; Guo, Yongqin; Li, Chuanbao; Zhang, Lu; Xing, Fubao; Wang, Wei; Gao, Jianping

2013-06-12

Stable Pickering emulsions were prepared using only graphene oxide (GO) as a stabilizer, and the effects of the type of oil, the sonication time, the GO concentration, the oil/water ratio, and the pH value on the stability, type, and morphology of these emulsions were investigated. In addition, the effects of salt and the extent of GO reduction on emulsion formation and stability were studied and discussed. The average droplet size decreased with sonication time and with GO concentration, and the emulsions tended to achieve good stability at intermediate oil/water ratios and at low pH values. In all solvents, the emulsions were of the oil-in-water type, but interestingly, some water-in-oil-in-water (w/o/w) multiple emulsion droplets were also observed with low GO concentrations, low pH values, high oil/water ratios, high salt concentrations, or moderately reduced GO in the benzyl chloride-water system. A Pickering emulsion stabilized by Ag/GO was also prepared, and its catalytic performance for the reduction of 4-nitrophenol was investigated. This research paves the way for the fabrication of graphene-based functional materials with novel nanostructures and microstructures.

Low temperature thermoelectric properties of Bi2-xSbxTeSe2 crystals near the n-p crossover

NASA Astrophysics Data System (ADS)

Fuccillo, M. K.; Charles, M. E.; Hor, Y. S.; Jia, Shuang; Cava, R. J.

2012-07-01

Seebeck coefficients, electrical resistivities, thermal conductivities and figure of merit ZT of Bi2-xSbxTeSe2 crystals (x=0.8, 0.9, 1.0, 1.1, and 1.2) measured along the hexagonal basal plane are presented. The crystals gradually change from n- to p-type with increasing Sb content, with the crossover lying in the region between x=1.0 and 1.1. The crossover is accounted for by a simple (p-n) electron-hole compensation model, as supported by carrier concentrations determined from Hall measurements. ZT was found to be maximized near the crossover on the p-type side, with the high electrical resistance of the Se-rich crystals apparently the limiting factor in the performance. These materials may serve as a basis for future nanostructuring or doping studies.

A program of 3 physical therapy modalities improves peripheral arterial disease in diabetes type 2 patients: a randomized controlled trial.

PubMed

Castro-Sánchez, Adelaida María; Matarán-Peñarrocha, Guillermo A; Feriche-Fernández-Castanys, Belen; Fernández-Sola, Cayetano; Sánchez-Labraca, Nuria; Moreno-Lorenzo, Carmen

2013-01-01

Type 2 diabetes is one of the main causes of peripheral vascular disease. The beneficial effects of exercise on glucose homeostasis include a marked stimulation of blood glucose utilization during and after its performance. The objective of this study was to determine the effects of a program of 3 physical therapy modalities on blood circulation in patients with type 2 diabetes with peripheral arterial disease. A randomized controlled trial was undertaken. Sixty-eight patients with type 2 diabetes with Leriche-Fontaine stage I or IIa peripheral arterial disease were randomly assigned to an exercise or placebo group. For 20 weeks, the exercise group underwent treatment comprising 3 exercises at proximal, medium, and distal segments of the lower limbs, and the placebo group received sham treatment with disconnected ultrasound equipment. Peripheral arterial disease was determined by evaluating the ankle/brachial index (ABI), Doppler flow velocity, blood parameters, cardiovascular risk score, and heart rate during exercise test. After 20 weeks of treatment, significant differences between groups were found in the following: right (P < .039) and left (P < .023) ABI; Doppler flow velocity (cm/s) in the right (P < .010) and left (P < .026) posterior tibial artery and in the right (P < .012) and left (P < .022) dorsalis pedis artery; and fibrinogen (P < .045), hemoglobin (P < .021), cholesterol (P < .012), high-density lipoprotein cholesterol (P < .031), and HbA1c (P < .034) values. There was no significant difference in low-density lipoprotein cholesterol values (P < .110) between the groups. A program of these physical therapy modalities improves ABI, Doppler flow velocity, and blood parameters in patients with type 2 diabetes.

Fabrication and characterization of piezoelectric micromachined ultrasonic transducers with thick composite PZT films.

PubMed

Wang, Zhihong; Zhu, Weiguang; Zhu, Hong; Miao, Jianmin; Chao, Chen; Zhao, Changlei; Tan, Ooi Kiang

2005-12-01

Ferroelectric microelectromechanical systems (MEMS) has been a growing area of research in past decades, in which ferroelectric films are combined with silicon technology for a variety of applications, such as piezo-electric micromachined ultrasonic transducers (pMUTs), which represent a new approach to ultrasound detection and generation. For ultrasound-radiating applications, thicker PZT films are preferred because generative force and response speed of the diaphragm-type transducers increase with increasing film thickness. However, integration of 4- to 20-microm thick PZT films on silicon wafer, either the deposition or the patterning, is still a bottleneck in the micromachining process. This paper reports on a diaphragm-type pMUT. A composite coating technique based on chemical solution deposition and high-energy ball milled powder has been used to fabricate thick PZT films. Micromachining of the pMUTs using such thick films has been investigated. The fabricated pMUT with crack-free PZT films up to 7-microm thick was evaluated as an ultrasonic transmitter. The generated sound pressure level of up to 120 dB indicates that the fabricated pMUT has very good ultrasound-radiating performance and, therefore, can be used to compose pMUT arrays for generating ultrasound beam with high directivity in numerous applications. The pMUT arrays also have been demonstrated.

Application of solvent floatation to separation and determination of triazine herbicides in honey by high-performance liquid chromatography.

PubMed

Wang, Kun; Jiang, Jia; Lv, Xinping; Zang, Shuang; Tian, Sizhu; Zhang, Hanqi; Yu, Aimin; Zhang, Ziwei; Yu, Yong

2018-03-01

Based on the foaming property of the honey, a rapid, simple, and effective method solvent floatation (SF) was developed and firstly applied to the extraction and separation of triazine herbicides in honey. The analytes were determined by high-performance liquid chromatography. Some parameters affecting the extraction efficiencies, such as the type and volume of extraction solvent, type of salt, amount of (NH 4 ) 2 SO 4 , pH value of sample solution, gas flow rate, and floatation time, were investigated and optimized. The limits of detection for analytes are in the range of 0.16-0.56 μg kg -1 . The recoveries and relative standard deviations for determining triazines in five real honey samples are in the range of 78.2-112.9 and 0.2-9.2%, respectively.

Sb2S3/Spiro-OMeTAD Inorganic-Organic Hybrid p-n Junction Diode for High Performance Self-Powered Photodetector.

PubMed

Bera, Ashok; Das Mahapatra, Ayon; Mondal, Sulakshana; Basak, Durga

2016-12-21

Organic-inorganic hybrid diodes are very promising for solution processing, low cost, high performance optoelectronic devices. Here, we report a high quality p-n heterojunction diode composed of n-type inorganic Sb 2 S 3 and p-type organic 2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD) with a rectification ratio of ∼10 2 at an applied bias of 1 V. On illumination with visible light (470 nm, 1.82 mW/cm 2 ), the current value in our device becomes 8 × 10 2 times that of its dark value even at a zero bias condition. The estimated responsivity value at zero bias is 0.087 A/W which is so far the highest reported for any organic-inorganic hybrid photodiode, to the best of our knowledge. It also exhibits a fast photoresponse time of <25 ms (instrumental limit). More importantly, our device can also detect visible light with power density as low as 8 μW/cm 2 with a photocurrent density of 1.2 μA/cm 2 and a photocurrent to dark current ratio of more than 8. We also demonstrate that the values of responsivity, short circuit current, and open circuit voltage of the photodetector can be improved significantly using a thin layer of TiO 2 hole-blocking layer. These findings suggest Sb 2 S 3 /spiro-OMeTAD heterojuncton as a promising candidate for efficient self-powered low visible light photodetector.

Effects of high intensity interval training versus moderate intensity continuous training on the reduction of oxidative stress in type 2 diabetic adult patients: CAT.

PubMed

Poblete Aro, Carlos Emilio; Russell Guzmán, Javier Antonio; Soto Muñoz, Marcelo Enrique; Villegas González, Bastián Eduardo

2015-08-13

Oxidative stress is caused by an imbalance between an excessive production of reactive oxygen species and/or a deficiency in the level of endogenous and exogenous antioxidant defenses. The presence of reactive oxygen species in large concentrations and for long periods is associated with the occurrence of various diseases, including type 2 diabetes mellitus. Exercise represents an effective means for the prevention and treatment of type 2 diabetes mellitus, and is also able to reduce long-term oxidative stress levels. High-intensity interval training has shown to be an efficient and viable option for type 2 diabetes mellitus control. In turn, high-intensity interval training seems to have positive effects on oxidative stress levels by increasing levels of endogenous antioxidants. To assess the validity and applicability of the results regarding the effectiveness of high-intensity interval training compared to moderate intensity continuous training to reduce oxidative stress in patients with type 2 diabetes mellitus and to answer the following question: In adults with type 2 diabetes mellitus, can the method of high-intensity interval training, compared to moderate intensity continuous training reduce oxidative stress levels? We performed a critical analysis of the article "Continuous training vs Interval training in glycemic control and macro and microvascular reactivity in patients with type 2 diabetes". No statistically significant differences were observed in concentrations of superoxide dismutase in any of the experimental groups. Only in the interval group a decrease in malondialdehyde regarding control group and baseline (p<0.05) was observed. In addition, only in the interval group there was an increase in glutathione peroxidase compared to the group of continuous aerobic training and baseline (p<0.05). Nitric oxide showed a significant increase regarding the control, continuous aerobic group and baseline (p<0.05) in the interval training group. Despite the fact that both training groups show improvements over markers of lipid profile and fitness, high intensity interval training has shown to be more effective in the normalization of oxidative stress, impacting positively on the concentration of pro-oxidant markers and antioxidants.

InP tunnel junction for InGaAs/InP tandem solar cells

NASA Technical Reports Server (NTRS)

Vilela, M. F.; Freundlich, A.; Bensaoula, A.; Medelci, N.; Renaud, P.

1995-01-01

Chemical beam epitaxy (CBE) has been shown to allow the growth of high quality materials with reproducible complex compositional and doping profiles. The main advantage of CBE compared to metalorganic chemical vapor deposition (MOCVD), the most popular technique for InP-based photovoltaic device fabrication, is the ability to grow high purity epilayers at much lower temperatures (450-530 C). We have previously shown that CBE is perfectly suited toward the fabrication of complex photovoltaic devices such as InP/InGaAs monolithically integrated tandem solar cells, because its low process temperature preserves the electrical characteristics of the InGaAs tunnel junction commonly used as an ohmic interconnect. In this work using CBE for the fabrication of optically transparent (with respect to the bottom cell) InP tunnel diodes is demonstrated. Epitaxial growth were performed in a Riber CBE 32 system using PH3 and TMIn as III and V precursors. Solid Be (p-type) and Si (n-type) have been used as doping sources, allowing doping levels up to 2 x 10(exp -19)/cu cm and 1 x 10(exp -19)/cu cm for n and p type respectively. The InP tunnel junction characteristics and the influence of the growth's conditions (temperature, growth rate) over its performance have been carefully investigated. InP p(++)/n(++) tunnel junction with peak current densities up to 1600 A/sq cm and maximum specific resistivities (V(sub p)/I(sub p) - peak voltage to peak current ratio) in the range of 10(exp -4) Omega-sq cm were obtained. The obtained peak current densities exceed the highest results previously reported for their lattice matched counterparts, In(0.53)Ga( 0.47)As and should allow the realization of improved minimal absorption losses in the interconnect InP/InGaAs tandem devices for Space applications. Owing to the low process temperature required for the top cell, these devices exhibit almost no degradation of its characteristics after the growth of subsequent thick InP layer suggesting minimal doping cross diffusion in the narrow space-charge region (approximately 1-5 nm) of the device. The fabrication of tandem devices using InP tunnel diodes as interconnect is in progress and will be reported at the conference.

Associations of advanced glycation end-products with cognitive functions in individuals with and without type 2 diabetes: the maastricht study.

PubMed

Spauwen, P J J; van Eupen, M G A; Köhler, S; Stehouwer, C D A; Verhey, F R J; van der Kallen, C J H; Sep, S J S; Koster, A; Schaper, N C; Dagnelie, P C; Schalkwijk, C G; Schram, M T; van Boxtel, M P J

2015-03-01

Advanced glycation end-products (AGEs) are thought to be involved in the pathogenesis of Alzheimer's disease. AGEs are products resulting from nonenzymatic chemical reactions between reduced sugars and proteins, which accumulate during natural aging, and their accumulation is accelerated in hyperglycemic conditions such as type 2 diabetes mellitus. The objective of the study was to examine associations between AGEs and cognitive functions. This study was performed as part of the Maastricht Study, a population-based cohort study in which, by design, 215 participants (28.1%) had type 2 diabetes mellitus. We examined associations of skin autofluorescence (SAF) (n = 764), an overall estimate of skin AGEs, and specific plasma protein-bound AGEs (n = 781) with performance on tests for global cognitive functioning, information processing speed, verbal memory (immediate and delayed word recall), and response inhibition. After adjustment for demographics, diabetes, smoking, alcohol, waist circumference, total cholesterol/high-density lipoprotein cholesterol ratio, triglycerides, and lipid-lowering medication use, higher SAF was significantly associated with worse delayed word recall (regression coefficient, b = -0.44; P = .04), and response inhibition (b = 0.03; P = .04). After further adjustment for systolic blood pressure, cardiovascular disease, estimated glomerular filtration rate, and depression, associations were attenuated (delayed word recall, b = -0.38, P = .07; response inhibition, b = 0.02, P = .07). Higher pentosidine levels were associated with worse global cognitive functioning (b = -0.61; P = .04) after full adjustment, but other plasma AGEs were not. Associations did not differ between individuals with and without diabetes. We found inverse associations of SAF (a noninvasive marker for tissue AGEs) with cognitive performance, which were attenuated after adjustment for vascular risk factors and depression.

Fingerprint chromatogram analysis of Pseudostellaria heterophylla (Miq.) Pax root by high performance liquid chromatography.

PubMed

Han, Chao; Chen, Junhui; Chen, Bo; Lee, Frank Sen-Chun; Wang, Xiaoru

2006-09-01

A simple and reliable high performance liquid chromatographic (HPLC) method has been developed and validated for the fingerprinting of extracts from the root of Pseudostellaria heterophylla (Miq.) Pax. HPLC with gradient elution was performed on an authentic reference standard of powdered P. heterophylla (Miq.) Pax root and 11 plant samples of the root were collected from different geographic locations. The HPLC chromatograms have been standardized through the selection and identification of reference peaks and the normalization of retention times and peak intensities of all the common peaks. The standardized HPLC fingerprints show high stability and reproducibility, and thus can be used effectively for the screening analysis or quality assessment of the root or its derived products. Similarity index calculations based on cosine angle values or correlation methods have been performed on the HPLC fingerprints. As a group, the fingerprints of the P. heterophylla (Miq.) Pax samples studied are highly correlated with closely similar fingerprints. Within the group, the samples can be further divided into subgroups based on hierarchical clustering analysis (HCA). Sample grouping based on HCA coincides nicely with those based on the geographical origins of the samples. The HPLC fingerprinting techniques thus have high potential in authentication or source-tracing types of applications.

Clinical application of a color map pattern on shear-wave elastography for invasive breast cancer.

PubMed

Lee, Seokwon; Jung, Younglae; Bae, Youngtae

2016-03-01

The aim of this study was to classify the color map pattern on shear-wave elastography (SWE) and to determine its association with clinicopathological factors for clinical application in invasive breast cancer. From June to December 2014, 103 invasive breast cancers were imaged by B-mode ultrasonography (US) and SWE just before surgery. The color map pattern identified on the SWE could be classified into three main categories: type 1 (diffuse pattern), increased stiffness in the surrounding stroma and the interior lesion itself; type 2 (lateral pattern), marked peri-tumoral stiffness at the anterior and lateral portions with no or minor stiffness at the posterior portion; and type 3 (rim-off pattern), marked peri-tumoral stiffness at the anterior and posterior portion with no or minor stiffness at both lateral portions. High-grade density on mammography (grade 3-4) was more frequent in the type 1 pattern than the other pattern types (80.5% in high-grade density vs. 19.5% in low-grade density). For type 1 tumors, the extent of synchronous non-invasive cancers (pT0), ductal carcinoma in situ (DCIS), was 1.8-2.0 times wider than that measured by US or magnetic resonance imaging (MRI). For type 2 tumors, the invasive tumor components (pT size) size was 1.3 times greater than measured by MRI (p = 0.049). On the other hand, the pT size and pT0 extent of type 3 tumors were almost equal to the preoperative US and MRI measurements. In terms of immunohistochemical (IHC) profiles, type 3 tumors showed a high histologic grade (p = 0.021), poor differentiation (p = 0.009), presence of necrosis (p = 0.018), and high Ki-67 (p = 0.002). The percentage of HER2-positive cancers was relatively high within the type 2 group, and the percentage of triple negative breast cancer was relatively high in the type 3 group (p = 0.011). We expect that assessments of the SWE color map pattern will prove useful for surgical or therapeutic plan decisions and to predict prognosis in invasive breast cancer patients. Copyright © 2015 Elsevier Ltd. All rights reserved.

Resveratrol supplementation does not augment performance adaptations or fibre-type-specific responses to high-intensity interval training in humans.

PubMed

Scribbans, Trisha D; Ma, Jasmin K; Edgett, Brittany A; Vorobej, Kira A; Mitchell, Andrew S; Zelt, Jason G E; Simpson, Craig A; Quadrilatero, Joe; Gurd, Brendon J

2014-11-01

The present study examined the effect of concurrent exercise training and daily resveratrol (RSV) supplementation (150 mg) on training-induced adaptations following low-dose high-intensity interval training (HIIT). Sixteen recreationally active (∼22 years, ∼51 mL·kg(-1)·min(-1)) men were randomly assigned in a double-blind fashion to either the RSV or placebo group with both groups performing 4 weeks of HIIT 3 days per week. Before and after training, participants had a resting muscle biopsy taken, completed a peak oxygen uptake test, a Wingate test, and a submaximal exercise test. A main effect of training (p < 0.05) and interaction effect (p < 0.05) on peak aerobic power was observed; post hoc pairwise comparisons revealed that a significant (p < 0.05) increase occurred in the placebo group only. Main effects of training (p < 0.05) were observed for both peak oxygen uptake (placebo - pretraining: 51.3 ± 1.8, post-training: 54.5 ± 1.5 mL·kg(-1)·min(-1), effect size (ES) = 0.93; RSV - pretraining: 49.6 ± 2.2, post-training: 52.3 ± 2.5 mL·kg(-1)·min(-1), ES = 0.50) and Wingate peak power (placebo: pretraining: 747 ± 39, post-training: 809 ± 31 W, ES = 0.84; RSV - pretraining: 679 ± 39, post-training: 691 ± 43 W, ES = 0.12). Fibre-type distribution was unchanged, while a main effect of training (p < 0.05) was observed for succinate dehydrogenase activity and glycogen content, but not α-glycerophosphate dehydrogenase activity or intramuscular lipids in type I and IIA fibres. The fold change in PGC-1α, SIRT1, and SOD2 gene expression following training was significantly (p < 0.05) lower in the RSV group than placebo. These results suggest that concurrent exercise training and RSV supplementation may alter the normal training response induced by low-volume HIIT.

Monolithic interconnected module with a tunnel junction for enhanced electrical and optical performance

DOEpatents

Murray, Christopher S.; Wilt, David M.

2000-01-01

An improved thermophotovoltaic (TPV) n/p/n device is provided. Monolithic Interconnected Modules (MIMS), semiconductor devices converting infrared radiation to electricity, have been developed with improved electrical and optical performance. The structure is an n-type emitter on a p-type base with an n-type lateral conduction layer. The incorporation of a tunnel junction and the reduction in the amount of p-type material used results in negligible parasitic absorption, decreased series resistance, increased voltage and increased active area. The novel use of a tunnel junction results in the potential for a TPV device with efficiency greater than 24%.

The effectiveness of an intensive care quick reference checklist manual--a randomized simulation-based trial.

PubMed

Just, Katja S; Hubrich, Svenja; Schmidtke, Daniel; Scheifes, Andrea; Gerbershagen, Mark U; Wappler, Frank; Grensemann, Joern

2015-04-01

We aimed to test the effectiveness of checklists for emergency procedures on medical staff performance in intensive care crises. This is a prospective single-center randomized trial in a high-fidelity simulation center modeling an intensive care unit (ICU) in a tertiary care hospital in Germany. Teams consisted of 1 ICU resident and 2 ICU nurses (in total, n = 48). All completed 4 crisis scenarios, in which they were randomized to use checklists or to perform without any aid. In 2 of the scenarios, checklists could be used immediately (type 1 scenarios); and for the remaining, some further steps, for example, confirming diagnosis, were required first (type 2 scenarios). Outcome measurements were number of predefined items and time to completion of more than 50% and more than 75% of steps, respectively. When using checklists, participants initiated items faster and more completely according to appropriate treatment guidelines (9 vs 7 items with and without checklists, P < .05). Benefit of checklists was better in type 2 scenarios than in type 1 scenarios (2 vs 1 additional item, P < .05). In type 2 scenarios, time to complete 50% and 75% of items was faster with the use of checklists (P < .005). Use of checklists in ICU crises has a benefit on the completion of critical treatment steps. Within the type 2 scenarios, items were fulfilled faster with checklists. The implementation of checklists for intensive care crises is a promising approach that may improve patients' care. Copyright © 2014 Elsevier Inc. All rights reserved.

Thermoelectric properties of SnSe2 monolayer.

PubMed

Li, Guanpeng; Ding, Guangqian; Gao, Guoying

2017-01-11

The 2H (MoS 2 -type) phase of 2D transition metal dichalcogenides (TMDCs) has been extensively studied and exhibits excellent electronic and optoelectronic properties, but the high phonon thermal conductivity is detrimental to the thermoelectric performances. Here, we use first-principles methods combined with Boltzmann transport theory to calculate the electronic and phononic transport properties of 1T (CdI 2 -type) SnSe 2 monolayer, a recently realized 2D metal dichalcogenide semiconductor. The calculated band gap is 0.85 eV, which is a little larger than the bulk value. Lower phonon thermal conductivity and higher power factor are obtained in 1T-SnSe 2 monolayer compared to 2H-TMDCs monolayers. The low phonon thermal conductivity (3.27 W mK -1 at room temperature) is mainly due to the low phonon frequency of acoustic modes and the coupling of acoustic modes with optical modes. We also find that the p-type has better thermoelectric performance than the n-type, and the figure of merit within p-type can reach 0.94 at 600 K for 1T-SnSe 2 monolayer, which is higher than those of most 2H-TMDCs monolayers, making 1T-SnSe 2 monolayer a promising candidate for thermoelectric applications.

Cell kinetics and genetic instabilities in differentiated type early gastric cancers with different mucin phenotype.

PubMed

Shibata, Naomi; Watari, Jiro; Fujiya, Mikihiro; Tanno, Satoshi; Saitoh, Yusuke; Kohgo, Yutaka

2003-01-01

To clarify the biological impact and molecular pathogenesis of cellular phenotype in differentiated-type gastric cancers (DGCs), we investigated cell kinetics and genetic instabilities in early stage of DGCs. A total of 43 early gastric cancers (EGCs) were studied. EGCs were divided into 3 phenotypic categories: gastric (G type, n = 11), ordinary (O type, n = 20), and complete intestinal (CI type, n = 12) based on the combination of HGM, ConA, MUC2, and CD10. Proliferative index (PI), apoptotic index (AI), and p53 overexpression were investigated by immunohistochemical staining with anti-Ki-67, the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling method, and p53 antibody, respectively. Using a high-resolution fluorescent microsatellite analysis system, microsatellite instability (MSI) and loss of heterozygosity (LOH) were examined. Frameshift mutation analysis of transforming growth factor-beta type II receptor (TGF-betaRII) and bcl-2-associated X (BAX) in cancers with MSI was also performed. The mean AI/PI ratio values were 0.04 for G-type, 0.10 for O-type, and 0.13 for CI-type cancers--significantly lower in G type than in O and CI types (P = 0.02 and P = 0.001, respectively). No difference in the incidence of MSI and LOH was seen among the 3 cellular phenotypes. However, the major pattern of MSI, which showed drastic and widely dispersed changes and is related to an increased risk for cancer, was significantly higher in G and O types than in CI type (P <0.005). No frame shift mutations of TGF-betaRII or BAX were found in CI-type cancers. These results indicate that G-type cancers are likely to show more aggressive behaviors than CI-type cancers, and that O-type cancers show the intermediate characteristics of both types. However, the molecular pathogenesis of each phenotypic cancer is not associated with microsatellite alterations. Copyright 2003, Elsevier Science (USA). All rights reserved.

Sodium Butyrate Protects -Against High Fat Diet-Induced Cardiac Dysfunction and Metabolic Disorders in Type II Diabetic Mice.

PubMed

Zhang, Ling; Du, Jianfeng; Yano, Naohiro; Wang, Hao; Zhao, Yu Tina; Dubielecka, Patrycja M; Zhuang, Shougang; Chin, Y Eugene; Qin, Gangjian; Zhao, Ting C

2017-08-01

Histone deacetylases are recently identified to act as key regulators for cardiac pathophysiology and metabolic disorders. However, the function of histone deacetylase (HDAC) in controlling cardiac performance in Type II diabetes and obesity remains unknown. Here, we determine whether HDAC inhibition attenuates high fat diet (HFD)-induced cardiac dysfunction and improves metabolic features. Adult mice were fed with either HFD or standard chow food for 24 weeks. Starting at 12 weeks, mice were divided into four groups randomly, in which sodium butyrate (1%), a potent HDAC inhibitor, was provided to chow and HFD-fed mice in drinking water, respectively. Glucose intolerance, metabolic parameters, cardiac function, and remodeling were assessed. Histological analysis and cellular signaling were examined at 24 weeks following euthanization of mice. HFD-fed mice demonstrated myocardial dysfunction and profound interstitial fibrosis, which were attenuated by HDAC inhibition. HFD-induced metabolic syndrome features insulin resistance, obesity, hyperinsulinemia, hyperglycemia, lipid accumulations, and cardiac hypertrophy, these effects were prevented by HDAC inhibition. Furthermore, HDAC inhibition attenuated myocyte apoptosis, reduced production of reactive oxygen species, and increased angiogenesis in the HFD-fed myocardium. Notably, HFD induced decreases in MKK3, p38, p38 regulated/activated protein kinase (PRAK), and Akt-1, but not p44/42 phosphorylation, which were prevented by HDAC inhibition. These results suggest that HDAC inhibition plays a critical role to preserve cardiac performance and mitigate metabolic disorders in obesity and diabetes, which is associated with MKK3/p38/PRAK pathway. The study holds promise in developing a new therapeutic strategy in the treatment of Type II diabetic-induced heart failure and metabolic disorders. J. Cell. Biochem. 118: 2395-2408, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

P-stop isolation study of irradiated n-in-p type silicon strip sensors for harsh radiation environments

NASA Astrophysics Data System (ADS)

Printz, Martin; CMS Tracker Collaboration

2016-09-01

In order to determine the most radiation hard silicon sensors for the CMS Experiment after the Phase II Upgrade in 2023 a comprehensive study of silicon sensors after a fluence of up to 1.5 ×1015neq /cm2 corresponding to 3000fb-1 after the HL-LHC era has been carried out. The results led to the decision that the future Outer Tracker (20 cm < R < 110 cm) of CMS will consist of n-in-p type sensors. This technology is more radiation hard but also the manufacturing is more challenging compared to p-in-n type sensors due to additional process steps in order to suppress the accumulation of electrons between the readout strips. One possible isolation technique of adjacent strips is the p-stop structure which is a p-type material implantation with a certain pattern for each individual strip. However, electrical breakdown and charge collection studies indicate that the process parameters of the p-stop structure have to be carefully calibrated in order to achieve a sufficient strip isolation but simultaneously high breakdown voltages. Therefore a study of the isolation characteristics with four different silicon sensor manufacturers has been executed in order to determine the most suitable p-stop parameters for the harsh radiation environment during HL-LHC. Several p-stop doping concentrations, doping depths and different p-stop pattern have been realized and experiments before and after irradiation with protons and neutrons have been performed and compared to T-CAD simulation studies with Synopsys Sentaurus. The measurements combine the electrical characteristics measured with a semi-automatic probestation with Sr90 signal measurements and analogue readout. Furthermore, some samples have been investigated with the help of a cosmic telescope with high resolution allowing charge collection studies of MIPs penetrating the sensor between two strips.

Predator personality and prey behavioural predictability jointly determine foraging performance.

PubMed

Chang, Chia-Chen; Teo, Huey Yee; Norma-Rashid, Y; Li, Daiqin

2017-01-17

Predator-prey interactions play important roles in ecological communities. Personality, consistent inter-individual differences in behaviour, of predators, prey or both are known to influence inter-specific interactions. An individual may also behave differently under the same situation and the level of such variability may differ between individuals. Such intra-individual variability (IIV) or predictability may be a trait on which selection can also act. A few studies have revealed the joint effect of personality types of both predators and prey on predator foraging performance. However, how personality type and IIV of both predators and prey jointly influence predator foraging performance remains untested empirically. Here, we addressed this using a specialized spider-eating jumping spider, Portia labiata (Salticidae), as the predator, and a jumping spider, Cosmophasis umbratica, as the prey. We examined personality types and IIVs of both P. labiata and C. umbratica and used their inter- and intra-individual behavioural variation as predictors of foraging performance (i.e., number of attempts to capture prey). Personality type and predictability had a joint effect on predator foraging performance. Aggressive predators performed better in capturing unpredictable (high IIV) prey than predictable (low IIV) prey, while docile predators demonstrated better performance when encountering predictable prey. This study highlights the importance of the joint effect of both predator and prey personality types and IIVs on predator-prey interactions.

Predator personality and prey behavioural predictability jointly determine foraging performance

PubMed Central

Chang, Chia-chen; Teo, Huey Yee; Norma-Rashid, Y.; Li, Daiqin

2017-01-01

Predator-prey interactions play important roles in ecological communities. Personality, consistent inter-individual differences in behaviour, of predators, prey or both are known to influence inter-specific interactions. An individual may also behave differently under the same situation and the level of such variability may differ between individuals. Such intra-individual variability (IIV) or predictability may be a trait on which selection can also act. A few studies have revealed the joint effect of personality types of both predators and prey on predator foraging performance. However, how personality type and IIV of both predators and prey jointly influence predator foraging performance remains untested empirically. Here, we addressed this using a specialized spider-eating jumping spider, Portia labiata (Salticidae), as the predator, and a jumping spider, Cosmophasis umbratica, as the prey. We examined personality types and IIVs of both P. labiata and C. umbratica and used their inter- and intra-individual behavioural variation as predictors of foraging performance (i.e., number of attempts to capture prey). Personality type and predictability had a joint effect on predator foraging performance. Aggressive predators performed better in capturing unpredictable (high IIV) prey than predictable (low IIV) prey, while docile predators demonstrated better performance when encountering predictable prey. This study highlights the importance of the joint effect of both predator and prey personality types and IIVs on predator-prey interactions. PMID:28094288

A new triclinic modification of the pyrochlore-type KOs{sub 2}O{sub 6} superconductor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Katrych, S.; Gu, Q.F.; Bukowski, Z.

2009-03-15

A new modification of KOs{sub 2}O{sub 6}, the representative of a new structural type (Pearson symbol aP18, a=5.5668(1) A, b=6.4519(2) A, c=7.2356(2) A, {alpha}=65.377(3){sup o}, {beta}=70.572(3){sup o}, {gamma}=75.613(2){sup o} space group P-1, no. 2 was synthesized employing high pressure technique. Its structure was determined by single-crystal X-ray diffraction. The structure can be described as two OsO{sub 6} octahedral chains relating to each other through inversion and forming big voids with K atoms inside. Quantum chemical calculations were performed on the novel compound and structurally related cubic compound. High-pressure X-ray study showed that cubic KOs{sub 2}O{sub 6} phase was stable upmore » to 32.5(2) GPa at room temperature. - Graphical abstract: A new modification of KOs{sub 2}O{sub 6}, the representative of a new structural type (Pearson symbol aP18, a=5.5668(1) A, b=6.4519(2) A, c=7.2356(2) A, {alpha}=65.377(3){sup o}, {beta}=70.572(3){sup o}, {gamma}=75.613(2){sup o} space group P-1, no. 2 was synthesized employing high pressure technique. The structure can be described as two OsO{sub 6} octahedral chains relating to each other through inversion and forming big voids with K atoms inside.« less

P-type hole mobility measurement in Na-doped BaSnO3

NASA Astrophysics Data System (ADS)

Hong, Sungyun; Jang, Yeaju; Park, Jisung; Char, Kookrin

P-type doping in oxide materials has been a difficult task because of the oxygen vacancies. Taking advantage of the excellent oxygen stability in BaSnO3 (BSO), we replaced Ba with Na in BSO to achieve p-type doping. Ba1-xNaxSnO3 (BNSO) films with varying dopant ratios were epitaxially grown by the pulsed laser deposition technique. We confirmed that the BNSO films were properly grown and determined their lattice constants with respect to the dopant ratio by x-ray diffraction. Due to the high resistance of the films at room temperature, we measured the transport properties of the BNSO films at temperatures ranging from 200 C to 400 C. Hall resistance measurements in a +/- 5 kG magnetic field were performed to confirm that the films are indeed p-type. As the temperature increased, the hole carrier concentration of the films increased while the film resistance decreased. The hole mobility values, in the tens of cm2/Vsec range, were found to decrease with the temperature. We will present the complete doping rate and temperature dependence of the hole mobility and compare their behavior with those of n-type La-doped BSO. Samsung science and technology foundation.

Association of type 1 diabetes and concentrations of drinking water components in Newfoundland and Labrador, Canada.

PubMed

Chafe, Roger; Aslanov, Rana; Sarkar, Atanu; Gregory, Peter; Comeau, Alex; Newhook, Leigh Anne

2018-01-01

To determine the association between drinking water quality and rates of type 1 diabetes in the Newfoundland and Labrador (NL) population, which has one of the highest incidences of type 1 diabetes reported globally. The study used a community-based, case-control design. We first calculated incidence rates of type 1 diabetes at the provincial, regional and community levels. The connection between incidence rates and components in public water supplies were then analyzed in three ways: to evaluate differences in water quality between communities with and without incident cases of type 1 diabetes, and to analyze the relationship between water quality and incidence rates of type 1 diabetes at both the community and regional levels. The provincial incidence of type 1 diabetes was 51.7/100 000 (0-14 year age group) for the period studied. In the community-based analysis, there were significant associations found between higher concentrations of arsenic (β=0.268, P=0.013) and fluoride (β=0.202, P=0.005) in drinking water and higher incidence of type 1 diabetes. In the regional analysis, barium (β=-0.478, P=0.009) and nickel (β=-0.354, P=0.050) concentrations were negatively associated with incidence of type 1 diabetes. We confirmed the high incidence of type 1 diabetes in NL. We also found that concentrations of some components in drinking water were associated with higher incidence of type 1 diabetes, but no component was found to have a significant association across the three different levels of analysis performed.

Improved high operating temperature MCT MWIR modules

NASA Astrophysics Data System (ADS)

Lutz, H.; Breiter, R.; Figgemeier, H.; Schallenberg, T.; Schirmacher, W.; Wollrab, R.

2014-06-01

High operating temperature (HOT) IR-detectors are a key factor to size, weight and power (SWaP) reduced IR-systems. Such systems are essential to provide infantrymen with low-weight handheld systems with increased battery lifetimes or most compact clip-on weapon sights in combination with high electro-optical performance offered by cooled IR-technology. AIM's MCT standard n-on-p technology with vacancy doping has been optimized over many years resulting in MWIR-detectors with excellent electro-optical performance up to operating temperatures of ~120K. In the last years the effort has been intensified to improve this standard technology by introducing extrinsic doping with Gold as an acceptor. As a consequence the dark current could considerably be suppressed and allows for operation at ~140K with good e/o performance. More detailed investigations showed that limitation for HOT > 140K is explained by consequences from rising dark current rather than from defective pixel level. Recently, several crucial parameters were identified showing great promise for further optimization of HOT-performance. Among those, p-type concentration could successfully be reduced from the mid 1016 / cm3 to the lower 1015/ cm3 range. Since AIM is one of the leading manufacturers of split linear cryocoolers, an increase in operating temperature will directly lead to IR-modules with improved SWaP characteristics by making use of the miniature members of its SX cooler family with single piston and balancer technology. The paper will present recent progress in the development of HOT MWIR-detector arrays at AIM and show electro-optical performance data in comparison to focal plane arrays produced in the standard technology.

Surface Charge Transfer Doping via Transition Metal Oxides for Efficient p-Type Doping of II-VI Nanostructures.

PubMed

Xia, Feifei; Shao, Zhibin; He, Yuanyuan; Wang, Rongbin; Wu, Xiaofeng; Jiang, Tianhao; Duhm, Steffen; Zhao, Jianwei; Lee, Shuit-Tong; Jie, Jiansheng

2016-11-22

Wide band gap II-VI nanostructures are important building blocks for new-generation electronic and optoelectronic devices. However, the difficulty of realizing p-type conductivity in these materials via conventional doping methods has severely handicapped the fabrication of p-n homojunctions and complementary circuits, which are the fundamental components for high-performance devices. Herein, by using first-principles density functional theory calculations, we demonstrated a simple yet efficient way to achieve controlled p-type doping on II-VI nanostructures via surface charge transfer doping (SCTD) using high work function transition metal oxides such as MoO 3 , WO 3 , CrO 3 , and V 2 O 5 as dopants. Our calculations revealed that these oxides were capable of drawing electrons from II-VI nanostructures, leading to accumulation of positive charges (holes injection) in the II-VI nanostructures. As a result, Fermi levels of the II-VI nanostructures were shifted toward the valence band regions after surface modifications, along with the large enhancement of work functions. In situ ultraviolet photoelectron spectroscopy and X-ray photoelectron spectroscopy characterizations verified the significant interfacial charge transfer between II-VI nanostructures and surface dopants. Both theoretical calculations and electrical transfer measurements on the II-VI nanostructure-based field-effect transistors clearly showed the p-type conductivity of the nanostructures after surface modifications. Strikingly, II-VI nanowires could undergo semiconductor-to-metal transition by further increasing the SCTD level. SCTD offers the possibility to create a variety of electronic and optoelectronic devices from the II-VI nanostructures via realization of complementary doping.

Economic decision-making in morning/evening-type people as a function of time of day.

PubMed

Correa, Angel; Ruiz-Herrera, Noelia; Ruz, Maria; Tonetti, Lorenzo; Martoni, Monica; Fabbri, Marco; Natale, Vincenzo

2017-01-01

Decision-making is affected by psychological factors like emotional state or cognitive control, which may also vary with circadian rhythmicity. Here, we tested the influence of chronotype (32 morning-type versus 32 evening-type) and time of day (9 a.m. versus 5 p.m.) on interpersonal decision-making as measured by the Ultimatum Game. Participants had to accept or reject different economic offers proposed by a virtual participant. Acceptance involved distribution of gains as proposed, whereas rejection resulted in no gain for either player. The results of the game showed a deviation from rational performance, as participants usually rejected the unfair offers. This behaviour was similar for both chronotype groups, and in both times of day. This result may reflect the robustness of decision-making strategies across standard circadian phases under ecological conditions. Furthermore, morning-types invested more time than evening-types to respond to high-uncertainty offers. This more cautious decision-making style of morning-types fits with our finding of higher proactive control as compared to evening-types when performing the AX-Continuous Performance Task. In line with the literature on personality traits, our results suggest that morning-types behave with more conscientiousness and less risk-taking than evening-type individuals.

Metagenomic Analysis of Gingival Sulcus Microbiota and Pathogenesis of Periodontitis Associated with Type 2 Diabetes Mellitus.

PubMed

Babaev, E A; Balmasova, I P; Mkrtumyan, A M; Kostryukova, S N; Vakhitova, E S; Il'ina, E N; Tsarev, V N; Gabibov, A G; Arutyunov, S D

2017-10-01

Biofilm of the gingival sulcus from 22 patients with type 2 diabetes mellitus and periodontitis, 30 patients with periodontitis not complicated by diabetes mellitus (reference group), and 22 healthy volunteers without signs of gingival disease (control group) was studied by quantitative PCR. Quantitative analysis for the content of P. gingivalis, T. forsythia, A. ctinomycetemcomitans, T. denticola, P. intermedia, F. nucleatum/periodonticum, and P. endodontalis in the dental plaque was performed with a Dentoscreen kit. The presence of other bacterial groups was verified by metagenomic sequencing of the 16S rRNA gene to evaluate some specific features of the etiological factor for periodontitis in type 2 diabetes mellitus. Specimens of the Porphiromonadaceae and Fusobacteriaceae families were characterized by an extremely high incidence in combined pathology. The amount of Sphingobacteriaceae bacteria in the biofilm was shown to decrease significantly during periodontitis. Metagenomic analysis confirmed the pathogenic role of microbiota in combined pathology, as well as the hypothesis on a possible influence of periodontitis on the course and development of type 2 diabetes mellitus.

Thermoelectric properties of p-type cubic and rhombohedral GeTe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xing, Guangzong; Sun, Jifeng; Li, Yuwei

Here, we investigate the electronic and thermoelectric properties of GeTe in both cubic and rhombohedral phases. We find that cubic GeTe has an electronic structure with a narrow band gap that is unfavorable at high temperature, where the cubic phase is normally stable. However, cubic GeTe has electronic features that may lead to p-type performance superior to the normal rhombohedral phase at lower temperature. This is explained in part by the combination of light and heavy band character that is very effective in obtaining high thermopower and conductivity. In addition, the valence band edge carrier pockets in cubic GeTe possessmore » the largest anisotropy among cubic IV-VI analogs. These effects are stronger than the effect of band convergence in the rhombohedral structure. The results suggest further study of stabilized cubic GeTe as a thermoelectric.« less

Thermoelectric properties of p-type cubic and rhombohedral GeTe

DOE PAGES

Xing, Guangzong; Sun, Jifeng; Li, Yuwei; ...

2018-05-21

Here, we investigate the electronic and thermoelectric properties of GeTe in both cubic and rhombohedral phases. We find that cubic GeTe has an electronic structure with a narrow band gap that is unfavorable at high temperature, where the cubic phase is normally stable. However, cubic GeTe has electronic features that may lead to p-type performance superior to the normal rhombohedral phase at lower temperature. This is explained in part by the combination of light and heavy band character that is very effective in obtaining high thermopower and conductivity. In addition, the valence band edge carrier pockets in cubic GeTe possessmore » the largest anisotropy among cubic IV-VI analogs. These effects are stronger than the effect of band convergence in the rhombohedral structure. The results suggest further study of stabilized cubic GeTe as a thermoelectric.« less

NetTurnP – Neural Network Prediction of Beta-turns by Use of Evolutionary Information and Predicted Protein Sequence Features

PubMed Central

Petersen, Bent; Lundegaard, Claus; Petersen, Thomas Nordahl

2010-01-01

β-turns are the most common type of non-repetitive structures, and constitute on average 25% of the amino acids in proteins. The formation of β-turns plays an important role in protein folding, protein stability and molecular recognition processes. In this work we present the neural network method NetTurnP, for prediction of two-class β-turns and prediction of the individual β-turn types, by use of evolutionary information and predicted protein sequence features. It has been evaluated against a commonly used dataset BT426, and achieves a Matthews correlation coefficient of 0.50, which is the highest reported performance on a two-class prediction of β-turn and not-β-turn. Furthermore NetTurnP shows improved performance on some of the specific β-turn types. In the present work, neural network methods have been trained to predict β-turn or not and individual β-turn types from the primary amino acid sequence. The individual β-turn types I, I', II, II', VIII, VIa1, VIa2, VIba and IV have been predicted based on classifications by PROMOTIF, and the two-class prediction of β-turn or not is a superset comprised of all β-turn types. The performance is evaluated using a golden set of non-homologous sequences known as BT426. Our two-class prediction method achieves a performance of: MCC  = 0.50, Qtotal = 82.1%, sensitivity  = 75.6%, PPV  = 68.8% and AUC  = 0.864. We have compared our performance to eleven other prediction methods that obtain Matthews correlation coefficients in the range of 0.17 – 0.47. For the type specific β-turn predictions, only type I and II can be predicted with reasonable Matthews correlation coefficients, where we obtain performance values of 0.36 and 0.31, respectively. Conclusion The NetTurnP method has been implemented as a webserver, which is freely available at http://www.cbs.dtu.dk/services/NetTurnP/. NetTurnP is the only available webserver that allows submission of multiple sequences. PMID:21152409

NetTurnP--neural network prediction of beta-turns by use of evolutionary information and predicted protein sequence features.

PubMed

Petersen, Bent; Lundegaard, Claus; Petersen, Thomas Nordahl

2010-11-30

β-turns are the most common type of non-repetitive structures, and constitute on average 25% of the amino acids in proteins. The formation of β-turns plays an important role in protein folding, protein stability and molecular recognition processes. In this work we present the neural network method NetTurnP, for prediction of two-class β-turns and prediction of the individual β-turn types, by use of evolutionary information and predicted protein sequence features. It has been evaluated against a commonly used dataset BT426, and achieves a Matthews correlation coefficient of 0.50, which is the highest reported performance on a two-class prediction of β-turn and not-β-turn. Furthermore NetTurnP shows improved performance on some of the specific β-turn types. In the present work, neural network methods have been trained to predict β-turn or not and individual β-turn types from the primary amino acid sequence. The individual β-turn types I, I', II, II', VIII, VIa1, VIa2, VIba and IV have been predicted based on classifications by PROMOTIF, and the two-class prediction of β-turn or not is a superset comprised of all β-turn types. The performance is evaluated using a golden set of non-homologous sequences known as BT426. Our two-class prediction method achieves a performance of: MCC=0.50, Qtotal=82.1%, sensitivity=75.6%, PPV=68.8% and AUC=0.864. We have compared our performance to eleven other prediction methods that obtain Matthews correlation coefficients in the range of 0.17-0.47. For the type specific β-turn predictions, only type I and II can be predicted with reasonable Matthews correlation coefficients, where we obtain performance values of 0.36 and 0.31, respectively. The NetTurnP method has been implemented as a webserver, which is freely available at http://www.cbs.dtu.dk/services/NetTurnP/. NetTurnP is the only available webserver that allows submission of multiple sequences.

Enhanced Activity and Acid pH Stability of Prussian Blue-type Oxygen Evolution Electrocatalysts Processed by Chemical Etching.

PubMed

Han, Lijuan; Tang, Pengyi; Reyes-Carmona, Álvaro; Rodríguez-García, Bárbara; Torréns, Mabel; Morante, Joan Ramon; Arbiol, Jordi; Galan-Mascaros, Jose Ramon

2016-12-14

The development of upscalable oxygen evolving electrocatalysts from earth-abundant metals able to operate in neutral or acidic environments and low overpotentials remains a fundamental challenge for the realization of artificial photosynthesis. In this study, we report a highly active phase of heterobimetallic cyanide-bridged electrocatalysts able to promote water oxidation under neutral, basic (pH < 13), and acidic conditions (pH > 1). Cobalt-iron Prussian blue-type thin films, formed by chemical etching of Co(OH) 1.0 (CO 3 ) 0.5 ·nH 2 O nanocrystals, yield a dramatic enhancement of the catalytic performance toward oxygen production, when compared with previous reports for analogous materials. Electrochemical, spectroscopic, and structural studies confirm the excellent performance, stability, and corrosion resistance, even when compared with state-of-the-art metal oxide catalysts under moderate overpotentials and in a remarkably large pH range, including acid media where most cost-effective water oxidation catalysts are not useful. The origin of the superior electrocatalytic activity toward water oxidation appears to be in the optimized interfacial matching between catalyst and electrode surface obtained through this fabrication method.

Ferroelectric-induced carrier modulation for ambipolar transition metal dichalcogenide transistors

NASA Astrophysics Data System (ADS)

Yin, Lei; Wang, Zhenxing; Wang, Feng; Xu, Kai; Cheng, Ruiqing; Wen, Yao; Li, Jie; He, Jun

2017-03-01

For multifarious electronic and optoelectronic applications, it is indispensable exploration of stable and simple method to modulate electrical behavior of transition metal dichalcogenides (TMDs). In this study, an effective method to adjust the electrical properties of ambipolar TMDs is developed by introducing the dipole electric field from poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) ferroelectric polymer. The transition from ambipolar to p-type conductive characteristics is realized, and the transistor performances are also significantly enhanced. Hole density of MoTe2- and WSe2-based back-gate field effect transistors increases by 4.4 and 2.5 times. Moreover, the corresponding hole mobilities are strikingly improved from 0.27 to 10.7 cm2 V-1 s-1 and from 1.6 to 59.8 cm2 V-1 s-1, respectively. After optimizing, p-channel MoTe2 phototransistors present ultrahigh responsivity of 3521 A/W, which is superior to most layered phototransistors. The remarkable control of conductive type, carrier concentration, and field-effect mobility of ambipolar TMDs via P(VDF-TrFE) treatment paves a way for realization of high-performance and versatile electronic and optoelectronic devices.

Search for Pauli exclusion principle violating atomic transitions and electron decay with a p-type point contact germanium detector

DOE PAGES

Abgrall, N.; Arnquist, I. J.; Avignone, F. T.; ...

2016-11-11

Here, a search for Pauli-exclusion-principle-violating K α electron transitions was performed using 89.5 kg-d of data collected with a p-type point contact high-purity germanium detector operated at the Kimballton Underground Research Facility. A lower limit on the transition lifetime of 5.8 × 10 30 s at 90% C.L. was set by looking for a peak at 10.6 keV resulting from the X-ray and Auger electrons present following the transition. A similar analysis was done to look for the decay of atomic K-shell electrons into neutrinos, resulting in a lower limit of 6.8 × 10 30 s at 90% C.L. Itmore » is estimated that the Majorana Demonstrator, a 44 kg array of p-type point contact detectors that will search for the neutrinoless double-beta decay of 76Ge, could improve upon these exclusion limits by an order of magnitude after three years of operation.« less

P-type field effect transistor based on Na-doped BaSnO3

NASA Astrophysics Data System (ADS)

Jang, Yeaju; Hong, Sungyun; Park, Jisung; Char, Kookrin

We fabricated field effect transistors (FET) based on the p-type Na-doped BaSnO3 (BNSO) channel layer. The properties of epitaxial BNSO channel layer were controlled by the doping rate. In order to modulate the p-type FET, we used amorphous HfOx and epitaxial BaHfO3 (BHO) gate oxides, both of which have high dielectric constants. HfOx was deposited by atomic-layer-deposition and BHO was epitaxially grown by pulsed laser deposition. The pulsed laser deposited SrRuO3 (SRO) was used as the source and the drain contacts. Indium-tin oxide and La-doped BaSnO3 were used as the gate electrodes on top of the HfOx and the BHO gate oxides, respectively. We will analyze and present the performances of the BNSO field effect transistor such as the IDS-VDS, the IDS-VGS, the Ion/Ioff ratio, and the field effect mobility. Samsung Science and Technology Foundation.

Low temperature mobility in hafnium-oxide gated germanium p-channel metal-oxide-semiconductor field-effect transistors

NASA Astrophysics Data System (ADS)

Beer, Chris; Whall, Terry; Parker, Evan; Leadley, David; De Jaeger, Brice; Nicholas, Gareth; Zimmerman, Paul; Meuris, Marc; Szostak, Slawomir; Gluszko, Grzegorz; Lukasiak, Lidia

2007-12-01

Effective mobility measurements have been made at 4.2K on high performance high-k gated germanium p-type metal-oxide-semiconductor field effect transistors with a range of Ge/gate dielectric interface state densities. The mobility is successfully modelled by assuming surface roughness and interface charge scattering at the SiO2 interlayer/Ge interface. The deduced interface charge density is approximately equal to the values obtained from the threshold voltage and subthreshold slope measurements on each device. A hydrogen anneal reduces both the interface state density and the surface root mean square roughness by 20%.

INTERNATIONAL CONFERENCE ON SEMICONDUCTOR INJECTION LASERS SELCO-87: High-performance 1.3-μm InGaAsP/InP heterostructures formed by two-phase liquid epitaxy

NASA Astrophysics Data System (ADS)

Novotný, J.; Procházková, O.; Šrobár, F.; Zelinka, J.

1988-11-01

A description is given of a two-phase liquid epitaxy method used to grow InGaAsP/InP heterostructures intended for injection lasers emitting in the 1.3-μm range. A study was made of heterostructures of three types: double, with an additional quaternary layer (λ approx 1.1 μm) adjoining the active layer; with two quaternary layers between the active layer and the InP confining layers. The configuration with two flanking quaternary layers was found to be the best from the point of view of the threshold current density, optical output power, and reproducibility.

Xylose fermentation to ethanol. A review

DOE Office of Scientific and Technical Information (OSTI.GOV)

McMillan, J D

1993-01-01

The past several years have seen tremendous progress in the understanding of xylose metabolism and in the identification, characterization, and development of strains with improved xylose fermentation characteristics. A survey of the numerous microorganisms capable of directly fermenting xylose to ethanol indicates that wild-type yeast and recombinant bacteria offer the best overall performance in terms of high yield, final ethanol concentration, and volumetric productivity. The best performing bacteria, yeast, and fungi can achieve yields greater than 0.4 g/g and final ethanol concentrations approaching 5%. Productivities remain low for most yeast and particularly for fungi, but volumetric productivities exceeding 1.0 g/L-hmore » have been reported for xylose-fermenting bacteria. In terms of wild-type microorganisms, strains of the yeast Pichia stipitis show the most promise in the short term for direct high-yield fermentation of xylose without byproduct formation. Of the recombinant xylose-fermenting microorganisms developed, recombinant E. coli ATTC 11303 (pLOI297) exhibits the most favorable performance characteristics reported to date.« less

Xylose fermentation to ethanol

DOE Office of Scientific and Technical Information (OSTI.GOV)

McMillan, J.D.

1993-01-01

The past several years have seen tremendous progress in the understanding of xylose metabolism and in the identification, characterization, and development of strains with improved xylose fermentation characteristics. A survey of the numerous microorganisms capable of directly fermenting xylose to ethanol indicates that wild-type yeast and recombinant bacteria offer the best overall performance in terms of high yield, final ethanol concentration, and volumetric productivity. The best performing bacteria, yeast, and fungi can achieve yields greater than 0.4 g/g and final ethanol concentrations approaching 5%. Productivities remain low for most yeast and particularly for fungi, but volumetric productivities exceeding 1.0 g/L-hmore » have been reported for xylose-fermenting bacteria. In terms of wild-type microorganisms, strains of the yeast Pichia stipitis show the most promise in the short term for direct high-yield fermentation of xylose without byproduct formation. Of the recombinant xylose-fermenting microorganisms developed, recombinant E. coli ATTC 11303 (pLOI297) exhibits the most favorable performance characteristics reported to date.« less

Impact of Channel, Stress-Relaxed Buffer, and S/D Si1- x Ge x Stressor on the Performance of 7-nm FinFET CMOS Design with the Implementation of Stress Engineering

NASA Astrophysics Data System (ADS)

Othman, Nurul Aida Farhana; Hatta, Sharifah Fatmadiana Wan Muhamad; Soin, Norhayati

2018-04-01

Stress-engineered fin-shaped field effect transistors (FinFET) using germanium (Ge) is a promising performance booster to replace silicon (Si) due to its high holes mobility. This paper presents a three-dimensional simulation by the Sentaurus technology computer-aided design to study the effects of stressors—channel stress, stress-relaxed buffer (SRB), and source/drain (S/D) epitaxial stress—on different bases of FinFET, specifically silicon germanium (SiGe) and Ge-based, whereby the latter is achieved by manipulating the Ge mole fraction inside the three layers; their effects on the devices' figures-of-merits were recorded. The simulation generates an advanced calibration process, by which the drift diffusion simulation was adopted for ballistic transport effects. The results show that current enhancement in p-type FinFET (p-FinFET) with 110% is almost twice that in n-type FinFET (n-FinFET) with 57%, with increasing strain inside the channel suggesting that the use of strain is more effective for holes. In SiGe-based n-FinFET, the use of a high-strained SRB layer can improve the drive current up to 112%, while the high-strain S/D epitaxial for Ge-based p-FinFET can enhance the on-state current to 262%. Further investigations show that the channel and S/D doping are affecting the performances of SiGe-based FinFET with similar importance. It is observed that doping concentrations play an important role in threshold voltage adjustment as well as in drive current and subthreshold leakage improvements.

Fabrication of high-performance UVC photodiodes by Al+3 ion adjustment in AZO/Si Heterostructures

NASA Astrophysics Data System (ADS)

Efafi, Babak; Mousavi, Seyedeh Soraya; Majlesara, Mohamad Hossein; Ghafary, Bijan; Sajad, Batool

2018-07-01

In this research, fabrication of high-performance UVC photodiodes based on Al: ZnO thin films is reported. AZO thin films were prepared through sol-gel based chemical routes (using organic precursors) followed by a spin coating method. The layers play a role of the n-type semiconductor deposited on the p-type silicon substrate which formed a p-n heterojunction. Optimizing the percentage of dopants, salt concentration, as well as deposition conditions, is essential for achieving high efficiency and reliable devices. For this aim, different samples were characterized under illumination of an ultraviolet source (254 nm, 268.27 μWcm-2). Then, I-V curves and photoresponsivity of the samples were recorded. A comparison between the results indicates that the sample prepared with a soil concentration of 1 M zinc acetate contains about 2 at. % aluminum has the highest responsivity among the others. Also, studying the photoluminescence spectra of the optimized sample demonstrates that it is significantly sensitive to the wavelength of 260 NM in UVC region. Moreover, the photocurrent to dark current ratio of 1.6 × 103, was measured for the most sensitive sample (with 2 at. % Al). In addition, the highest amount of quantum efficiency about 81% was also determined for this sample.

The role of cone-beam breast-CT for breast cancer detection relative to breast density.

PubMed

Wienbeck, Susanne; Uhlig, Johannes; Luftner-Nagel, Susanne; Zapf, Antonia; Surov, Alexey; von Fintel, Eva; Stahnke, Vera; Lotz, Joachim; Fischer, Uwe

2017-12-01

To evaluate the impact of breast density on the diagnostic accuracy of non-contrast cone-beam breast computed tomography (CBBCT) in comparison to mammography for the detection of breast masses. A retrospective study was conducted from August 2015 to July 2016. Fifty-nine patients (65 breasts, 112 lesions) with BI-RADS, 5th edition 4 or 5 assessment in mammography and/or ultrasound of the breast received an additional non-contrast CBBCT. Independent double blind reading by two radiologists was performed for mammography and CBBCT imaging. Sensitivity, specificity and AUC were compared between the modalities. Breast lesions were histologically examined in 85 of 112 lesions (76%). The overall sensitivity for CBBCT (reader 1: 91%, reader 2: 88%) was higher than in mammography (both: 68%, p<0.001), and also for the high-density group (p<0.05). The specificity and AUC was higher for mammography in comparison to CBBCT (p<0.05 and p<0.001). The interobserver agreement (ICC) between the readers was 90% (95% CI: 86-93%) for mammography and 87% (95% CI: 82-91%) for CBBCT. Compared with two-view mammography, non-contrast CBBCT has higher sensitivity, lower specificity, and lower AUC for breast mass detection in both high and low density breasts. • Overall sensitivity for non-contrast CBBCT ranged between 88%-91%. • Sensitivity was higher for CBBCT than mammography in both density types (p<0.001). • Specificity was higher for mammography than CBBCT in both density types (p<0.05). • AUC was larger for mammography than CBBCT in both density types (p<0.001).

Electrical properties of n-type GaSb substrates and p-type GaSb buffer layers for InAs/InGaSb superlattice infrared detectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitchel, W. C., E-mail: William.Mitchel.1@us.af.mil; Haugan, H. J.; Mou, Shin

2015-09-15

Lightly doped n-type GaSb substrates with p-type GaSb buffer layers are the preferred templates for growth of InAs/InGaSb superlattices used in infrared detector applications because of relatively high infrared transmission and a close lattice match to the superlattices. We report here temperature dependent resistivity and Hall effect measurements of bare substrates and substrate-p-type buffer layer structures grown by molecular beam epitaxy. Multicarrier analysis of the resistivity and Hall coefficient data demonstrate that high temperature transport in the substrates is due to conduction in both the high mobility zone center Γ band and the low mobility off-center L band. High overallmore » mobility values indicate the absence of close compensation and that improved infrared and transport properties were achieved by a reduction in intrinsic acceptor concentration. Standard transport measurements of the undoped buffer layers show p-type conduction up to 300 K indicating electrical isolation of the buffer layer from the lightly n-type GaSb substrate. However, the highest temperature data indicate the early stages of the expected p to n type conversion which leads to apparent anomalously high carrier concentrations and lower than expected mobilities. Data at 77 K indicate very high quality buffer layers.« less

Design of a highly sensitive ethanol sensor using a nano-coaxial p-Co3O4/n-TiO2 heterojunction synthesized at low temperature.

PubMed

Liang, Y Q; Cui, Z D; Zhu, S L; Li, Z Y; Yang, X J; Chen, Y J; Ma, J M

2013-11-21

In this paper, we describe the design, fabrication and gas-sensing tests of nano-coaxial p-Co3O4/n-TiO2 heterojunction. Specifically, uniform TiO2 nanotubular arrays have been assembled by anodization and used as templates for generation of the Co3O4 one-dimensional nanorods. The structure morphology and composition of as-prepared products have been characterized by SEM, XRD, TEM, and XPS. A possible growth mechanism governing the formation of such nano-coaxial heterojunctions is proposed. The TiO2 nanotube sensor shows a normal n-type response to reducing ethanol gas, whereas TiO2-Co3O4 exhibits p-type response with excellent sensing performances. This conversion of sensing behavior can be explained by the formation of p-n heterojunction structures. A possible sensing mechanism is also illustrated, which can provide theoretical guidance for the further development of advanced gas-sensitive materials with p-n heterojunction.

Method of forming thermally stable high-resistivity regions in n-type indium phosphide by oxygen implantation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thompson, P.E.; Dietrich, H.B.

1985-12-12

Objects of this invention are: to form high-temperature stable isolation regions in InP; to provide InP wafers that allow greater flexibility in the design and fabrication of discrete devices; to provide new and improved InP semiconductor devices in n-type InP; to provide high-resisitivity isolation regions in InP; to extend the usefulness of damage-induced isolation in n-type InP by making possible processes in which the isolation implantation precedes the alloying of ohmic contacts; and to provide n-type InP substrates without unwanted conductive layers. The above and other object are realized by an InP wafer comprising a S.I. InP substrate; a n-typemore » InP active layer disposed on the substrate; and oxygen ion implanted isolation regions disposed in the active layer. The S.I. InP dopant may comprise either Fe or Cr.« less

Comparison of gait after Syme and transtibial amputation in children: factors that may play a role in function.

PubMed

Jeans, Kelly A; Karol, Lori A; Cummings, Donald; Singhal, Kunal

2014-10-01

Preservation of maximal limb length during amputation is often recommended to maximize the efficiency and symmetry of gait. The goals of this study were to determine (1) whether there are gait differences between children with a Syme (or Boyd) amputation and those with a transtibial-level amputation, and (2) whether the type of prosthetic foot affects gait and PODCI (Pediatric Outcomes Data Collection Instrument) outcomes. Sixty-four patients (age range, 4.7 to 19.2 years) with unilateral below-the-knee prosthesis use (forty-one in the Syme group and twenty-three in the transtibial group) underwent gait analysis and review of data for the involved limb. The twelve prosthetic foot types were categorized as designed for a high, medium, or low activity level (e.g., Flex foot, dynamic response foot, or SACH). Statistical analyses were conducted. Kinematic differences of <4° in total prosthetic ankle motion and 8° in external hip rotation were seen between the Syme and transtibial groups. Ankle power was greater in the transtibial group, whereas the Syme group had greater coronal-plane hip power (p < 0.05). Prosthetic ankle motion was significantly greater in the high compared with the medium and low-performance feet. However, the PODCI happiness score was higher in patients with low compared with medium-performance feet (p < 0.05). Small differences in prosthetic ankle motion and power were found between children with Syme and transtibial amputations. Ankle motion was greater in patients using high-performance feet (9% of the total cohort) compared with medium-performance (59%) and low-performance (31%) feet. Despite the increased ankle motion achieved with high-performance dynamic feet, this advantage was not reflected in peak power of the prosthetic ankle or the PODCI sports/physical functioning subscale. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence. Copyright © 2014 by The Journal of Bone and Joint Surgery, Incorporated.

Environment Dependence of Disk Morphology of Spiral Galaxies

NASA Astrophysics Data System (ADS)

Ann, Hong Bae

2014-02-01

We analyze the dependence of disk morphology (arm class, Hubble type, bar type) of nearby spiral galaxies on the galaxy environment by using local background density (Σ_{n}), project distance (r_{p}), and tidal index (TI) as measures of the environment. There is a strong dependence of arm class and Hubble type on the galaxy environment, while the bar type exhibits a weak dependence with a high frequency of SB galaxies in high density regions. Grand design fractions and early-type fractions increase with increasing Σ_{n}, 1/r_{p}, and TI, while fractions of flocculent spirals and late-type spirals decrease. Multiple-arm and intermediate-type spirals exhibit nearly constant fractions with weak trends similar to grand design and early-type spirals. While bar types show only a marginal dependence on Σ_{n}, they show a fairly clear dependence on r_{p} with a high frequency of SB galaxies at small r_{p}. The arm class also exhibits a stronger correlation with r_{p} than Σ_{n} and TI, whereas the Hubble type exhibits similar correlations with Σ_{n} and r_{p}. This suggests that the arm class is mostly affected by the nearest neighbor while the Hubble type is affected by the local densities contributed by neighboring galaxies as well as the nearest neighbor.

Blocked versus randomized presentation modes differentially modulate feedback-related negativity and P3b amplitudes.

PubMed

Pfabigan, Daniela M; Zeiler, Michael; Lamm, Claus; Sailer, Uta

2014-04-01

Electrophysiological studies on feedback processing typically use a wide range of feedback stimuli which might not always be comparable. The current study investigated whether two indicators of feedback processing - feedback-related negativity (FRN) and P3b - differ for feedback stimuli with explicit (facial expressions) or assigned valence information (symbols). In addition, we assessed whether presenting feedback in either a trial-by-trial or a block-wise fashion affected these ERPs. EEG was recorded in three experiments while participants performed a time estimation task and received two different types of performance feedback. Only P3b amplitudes varied consistently in response to feedback type for both presentation types. Moreover, the blocked feedback type presentation yielded more distinct FRN peaks, higher effect sizes, and a significant relation between FRN amplitudes and behavioral task performance measures. Both stimulus type and presentation mode may provoke systematic changes in feedback-related ERPs. The current findings point at important potential confounds that need to be controlled for when designing FRN or P3b studies. Studies investigating P3b amplitudes using mixed types of stimuli have to be interpreted with caution. Furthermore, we suggest implementing a blocked presentation format when presenting different feedback types within the same experiment. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

In-silico Taxonomic Classification of 373 Genomes Reveals Species Misidentification and New Genospecies within the Genus Pseudomonas.

PubMed

Tran, Phuong N; Savka, Michael A; Gan, Han Ming

2017-01-01

The genus Pseudomonas has one of the largest diversity of species within the Bacteria kingdom. To date, its taxonomy is still being revised and updated. Due to the non-standardized procedure and ambiguous thresholds at species level, largely based on 16S rRNA gene or conventional biochemical assay, species identification of publicly available Pseudomonas genomes remains questionable. In this study, we performed a large-scale analysis of all Pseudomonas genomes with species designation (excluding the well-defined P. aeruginosa ) and re-evaluated their taxonomic assignment via in silico genome-genome hybridization and/or genetic comparison with valid type species. Three-hundred and seventy-three pseudomonad genomes were analyzed and subsequently clustered into 145 distinct genospecies. We detected 207 erroneous labels and corrected 43 to the proper species based on Average Nucleotide Identity Multilocus Sequence Typing (MLST) sequence similarity to the type strain. Surprisingly, more than half of the genomes initially designated as Pseudomonas syringae and Pseudomonas fluorescens should be classified either to a previously described species or to a new genospecies. Notably, high pairwise average nucleotide identity (>95%) indicating species-level similarity was observed between P. synxantha-P. libanensis, P. psychrotolerans - P. oryzihabitans , and P. kilonensis- P. brassicacearum , that were previously differentiated based on conventional biochemical tests and/or genome-genome hybridization techniques.

Low effective mass and carrier concentration optimization for high performance p-type Mg2(1-x)Li2xSi0.3Sn0.7 solid solutions.

PubMed

Zhang, Qiang; Cheng, Long; Liu, Wei; Zheng, Yun; Su, Xianli; Chi, Hang; Liu, Huijun; Yan, Yonggao; Tang, Xinfeng; Uher, Ctirad

2014-11-21

Mg2Si1-xSnx solid solutions are promising thermoelectric materials for power generation applications in the 500-800 K range. Outstanding n-type forms of these solid solutions have been developed in the past few years with the thermoelectric figure of merit ZT as high as 1.4. Unfortunately, no comparable performance has been achieved so far with p-type forms of the structure. In this work, we use Li doping on Mg sites in an attempt to enhance and control the concentration of hole carriers. We show that Li as well as Ga is a far more effective p-type dopant in comparison to Na or K. With the increasing content of Li, the electrical conductivity rises rapidly on account of a significantly enhanced density of holes. While the Seebeck coefficient decreases concomitantly, the power factor retains robust values supported by a rather high mobility of holes. Theoretical calculations indicate that Mg2Si0.3Sn0.7 intrinsically possesses the almost convergent double valence band structure (the light and heavy band), and Li doping retains a low density of states (DOS) on the top of the valence band, contrary to the Ga doping at the sites of Si/Sn. Low temperature specific heat capacity studies attest to a low DOS effective mass in Li-doped samples and consequently their larger hole mobility. The overall effect is a large power factor of Li-doped solid solutions. Although the thermal conductivity increases as more Li is incorporated in the structure, the enhanced carrier density effectively shifts the onset of intrinsic excitations (bipolar effect) to higher temperatures, and the beneficial role of phonon Umklapp processes as the primary limiting factor to the lattice thermal conductivity is thus extended. The final outcome is the figure of merit ZT ∼ 0.5 at 750 K for x = 0.07. This represents a 30% improvement in the figure of merit of p-type Mg2Si1-xSnx solid solutions over the literature values. Hence, designing low DOS near Fermi level EF for given carrier pockets can serve as an effective approach to optimize the PF and thus ZT value.

Cardiac size of high-volume resistance trained female athletes: shaping the body but not the heart.

PubMed

Venckunas, T; Simonavicius, J; Marcinkeviciene, J E

2016-03-01

Introduction Exercise training, besides many health benefits, may result in cardiac remodelling which is dependent on the type and amount of exercise performed. It is not clear, however, whether significant adaptation in cardiac structure is possible in females undergoing resistance type of exercise training. Rigorous high volume training of most muscle groups emphasising resistance exercises are being undertaken by athletes of some aesthetic sports such as female fitness (light bodybuilding). The impact of this type of training on cardiac adaptation has not been investigated until now. The aim of the current study was to disclose the effect of high volume resistance training on cardiac structure and function. Methods 11 top-level female fitness athletes and 20 sedentary age-matched controls were recruited to undergo two-dimensional echocardiography. Results Cardiac structure did not differ between elite female fitness athletes and controls (p > 0.05), and fitness athletes had a tendency for a smaller (p = 0.07) left ventricular (LV) mass indexed to lean body mass. Doppler diastolic function index (E/A ratio) and LV ejection fraction were similar between the groups (p > 0.05). Conclusions Elite female fitness athletes have normal cardiac size and function that do not differ from matched sedentary controls. Consequently, as high volume resistance training has no easily observable effect on adaptation of cardiac structure, when cardiac hypertrophy is present in young resistance-trained lean female, other reasons such as inherited cardiac disease are to be considered carefully.

Synthesis and characterizaton of inorganic materials for sodium-ion batteries

NASA Astrophysics Data System (ADS)

Shanmugam, Rengarajan

Development of low-cost energy storage devices is critical for wide-scale implementation of intermittent renewable energy technologies and improving the electricity grid. Commercial devices remain prohibitively expensive or lack the performance specifications for a wider market reach. Na-ion batteries would perfectly suited for these large-scale applications as the raw materials (such as soda ash, salt, etc.) are plentiful, inexpensive and geographically unconstrained. However, extensive materials research on insertion electrodes is required for better understanding of the electrochemical and structural properties and engineering high performance Na-ion batteries. This thesis research involves exploratory study on new insertion materials with various crystallographic structure-types and extensive characterization of promising new inorganic compositions. Tunnel-type materials, sodium nickel phosphate-Na4Ni7(PO4)6, and sodium cobalt titanate- Na0.8Co0.4Ti1.6O4, were investigated to capitalize on the intrinsic structural stability offered by framework materials. Sol-gel and solid-state reaction synthetic techniques were employed for inorganic powder synthesis. Galvanostatic and potentiostatic testing confirm reversible sodium insertion/de-insertion reactions albeit with inadequate electrochemical characteristics (high voltage hysteresis> 1V). Subsequent efforts involved investigating layer-structured materials supporting fast ionic transport for better electrochemical performance. P2-sodium nickel titanate, Na2/3[Ni1/3Ti2/3]O2 (P2NT), with prismatic sodium co-ordination, was synthesized by solid-state technique. The 'bifunctional' oxide contains Ni2+/4+ and Ti4+/3+ redox couples with redox potentials of 3.6 V, 0.7 V vs. Na/Na+, respectively. This bifunctional approach would simplify electrode processing and provide cost reduction opportunities in battery manufacturing. The structural changes monitored using ex-situ XRD demonstrate a favorably broad solid-solution domain. Manganese substitution, to form P2-Na2/3[Ni1/3Mn1/3Ti1/3]O2 (P2NMT), provides an enhanced high-current performance due to faster interfacial kinetics and accelerated charge carrier transport as shown by impedance spectroscopy and DC testing. Structural properties of P2NT material were studied using neutron diffraction and atomisitic simulations. Rietveld refinement shows that Naf sites have lower site occupancy than Nae sites due to unfavorable repulsive interactions from inline transition metal atoms. Buckingham and Morse-type models accurately predicted the experimental lattice parameters. The energy landscape was explored using energy minimization runs on disordered supercells. The simulated density maps are in agreement with the experiment densities with evidence of stacking fault formation. O3-sodium nickel titanate, Na0.9[Ni0.45Ti0.55]O2 (O3NT) with octahedral sodium co-ordination was synthesized by solid-state reaction technique. The influence of titanium on the poor cycleability of the O3-type electrodes was investigated. Ex-situ XRD shows two phase regions, comprised of O3+P3 phases, and a solid solution region, comprised of P3 phase. O3NT provides an excellent capacity retention of 99% for 115 cycles at C/2 rate. The good cycleability is attributed to the relative invariance of net impedance during electrode cycling using impedance spectroscopy.

Development of ultra-low noise, high performance 3-V Quantum Well Infrared Photodectors (QWIP's) for focal plane array staring image sensor systems

NASA Astrophysics Data System (ADS)

Li, Sheng S.

1993-08-01

During this reporting period we have continued to make excellent progress towards the program goals. We have made a major breakthrough in the development of a new normal incidence p-type strained layer InGaAs/InAlAs QWIP grown on InP by MBE, which achieved both the lowest dark current and highest detectivity ever reported for a QWIP operating at 8.1 um and 77 K. The device dark current at 77 K is one to two orders of magnitude smaller than its 300 K background photocurrent, which shows that this p-type strained layer QWIP is under BLIP operation at 77 K. Other tasks performed during this period include: (1) measured and compared the device dark current with 300 K background limited photocurrent (BLIP) for several QWIP's fabricated from GaAs/AlGaAs, InGaAs/InAlAs, and AlAs/AlGaAs material systems, (2) designed a broad band 2-D square mesh grating coupler for the dual-mode operation GaAs QWIP to enhance the coupling quantum efficiency and responsivity of this QWIP in the 3-5 and 8-12 um bands, (3) using a 2-D square mesh grating coupler to achieve maximum responsivity for an InGaAs SBTM QWIP, and (4) performed noise characterization on four different types of III-V QWIP's and identified their noise sources. Detailed results and accomplishments are discussed in this report.

Power profiles and short-term visual performance of soft contact lenses.

PubMed

Papas, Eric; Dahms, Anne; Carnt, Nicole; Tahhan, Nina; Ehrmann, Klaus

2009-04-01

To investigate the manner in which contemporary soft contact lenses differ in the distribution of optical power within their optic zones and establish if these variations affect the vision of wearers or the prescribing procedure for back vertex power (BVP). By using a Visionix VC 2001 contact lens power analyzer, power profiles were measured across the optic zones of the following contemporary contact lenses ACUVUE 2, ACUVUE ADVANCE, O2OPTIX, NIGHT & DAY and PureVision. Single BVP measures were obtained using a Nikon projection lensometer. Visual performance was assessed in 28 masked subjects who wore each lens type in random order. Measurements taken were high and low contrast visual acuity in normal illumination (250 Cd/m), high contrast acuity in reduced illumination (5 Cd/m), subjective visual quality using a numerical rating scale, and visual satisfaction rating using a Likert scale. Marked differences in the distribution of optical power across the optic zone were evident among the lens types. No significant differences were found for any of the visual performance variables (p > 0.05, analysis of variance with repeated measures and Friedman test). Variations in power profile between contemporary soft lens types exist but do not, in general, result in measurable visual performance differences in the short term, nor do they substantially influence the BVP required for optimal correction.

Cognitive-Motor Interference on Upper Extremity Motor Performance in a Robot-Assisted Planar Reaching Task Among Patients With Stroke.

PubMed

Shin, Joon-Ho; Park, Gyulee; Cho, Duk Youn

2017-04-01

To explore motor performance on 2 different cognitive tasks during robotic rehabilitation in which motor performance was longitudinally assessed. Prospective study. Rehabilitation hospital. Patients (N=22) with chronic stroke and upper extremity impairment. A total of 640 repetitions of robot-assisted planar reaching, 5 times a week for 4 weeks. Longitudinal robotic evaluations regarding motor performance included smoothness, mean velocity, path error, and reach error by the type of cognitive task. Dual-task effects (DTEs) of motor performance were computed to analyze the effect of the cognitive task on dual-task interference. Cognitive task type influenced smoothness (P=.006), the DTEs of smoothness (P=.002), and the DTEs of reach error (P=.052). Robotic rehabilitation improved smoothness (P=.007) and reach error (P=.078), while stroke severity affected smoothness (P=.01), reach error (P<.001), and path error (P=.01). Robotic rehabilitation or severity did not affect the DTEs of motor performance. The results provide evidence for the effect of cognitive-motor interference on upper extremity performance among participants with stroke using a robotic-guided rehabilitation system. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Gene disruption in Salmonella typhimurim by modified λ Red disruption system.

PubMed

Ahani Azari, A; Zahraei Salehi, T; Nayeri Fasaei, B; Alebouyeh, M

2015-01-01

There are many techniques to knock out directed genes in bacteria, some of which have been described in Salmonella species. In this study, a combination of SOEing PCR method and the λ Red disruption system were used to disrupt phoP gene in wild type and standard strains of Salmonella typhimurium. Three standards PCR and one fusion PCR reactions were performed to construct a linear DNA including upstream and downstream of phoP gene and Kanamycin cassette. As a template plasmid, we used pKD4 which carries kanamycin gene flanked by FRT (FLP recognition target) sites. The resulting construct was electroporated into prepared competent cells of S. typhimurium. The transformants colonies related to the standard strain appeared on the LB-Km-agar plates after incubation, but there was no colony on LB-Km-agar plates corresponding to the wild type strain. The failure in transformation of the wild type strain may be because of inflexibility of the λ Red disruption system in this strain or its unique restriction-modification system. However, by this construct we are able to generate phoP mutant in many of the Salmonella species due to high homology of the phoP gene which exists in different species.

Performance of primary repair on colon injuries sustained from low-versus high-energy projectiles.

PubMed

Lazovic, Ranko; Radojevic, Nemanja; Curovic, Ivana

2016-04-01

Among various reasons, colon injuries may be caused by low- or high-energy firearm bullets, with the latter producing a temporary cavitation phenomenon. The available treatment options include primary repair and two-stage management, but recent studies have shown that primary repair can be widely used with a high success rate. This paper investigates the differences in performance of primary repair on these two types of colon injuries. Two groups of patients who sustained colon injuries due to single gunshot wounds, were retrospectively categorized based on the type of bullet. Primary colon repair was performed in all patients selected based on the inclusion and exclusion criteria (Stone and Fabian's criteria). An almost absolute homogeneity was attained among the groups in terms of age, latent time before surgery, and four trauma indexes. Only one patient from the low-energy firearm projectile group (4%) developed a postsurgical complication versus nine patients (25.8%) from the high-energy group, showing statistically significant difference (p = 0.03). These nine patients experienced the following postsurgical complications: pneumonia, abscess, fistula, suture leakage, and one multiorgan failure with sepsis. Previous studies concluded that one-stage primary repair is the best treatment option for colon injuries. However, terminal ballistics testing determined the projectile's path through the body and revealed that low-energy projectiles caused considerably lesser damage than their high-energy counterparts. Primary colon repair must be performed definitely for low-energy short firearm injuries but very carefully for high-energy injuries. Given these findings, we suggest that the treatment option should be determined based not only on the bullet type alone but also on other clinical findings. Copyright © 2016 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Performance of primary repair on colon injuries sustained from low-versus high-energy projectiles

PubMed Central

Lazovic, Ranko; Radojevic, Nemanja; Curovic, Ivana

2017-01-01

Among various reasons, colon injuries may be caused by low- or high-energy firearm bullets, with the latter producing a temporary cavitation phenomenon. The available treatment options include primary repair and two-stage management, but recent studies have shown that primary repair can be widely used with a high success rate. This paper investigates the differences in performance of primary repair on these two types of colon injuries. Two groups of patients who sustained colon injuries due to single gunshot wounds, were retrospectively categorized based on the type of bullet. Primary colon repair was performed in all patients selected based on the inclusion and exclusion criteria (Stone and Fabian's criteria). An almost absolute homogeneity was attained among the groups in terms of age, latent time before surgery, and four trauma indexes. Only one patient from the low-energy firearm projectile group (4%) developed a postsurgical complication versus nine patients (25.8%) from the high-energy group, showing statistically significant difference (p = 0.03). These nine patients experienced the following postsurgical complications: pneumonia, abscess, fistula, suture leakage, and one multiorgan failure with sepsis. Previous studies concluded that one-stage primary repair is the best treatment option for colon injuries. However, terminal ballistics testing determined the projectile's path through the body and revealed that low-energy projectiles caused considerably lesser damage than their high-energy counterparts. Primary colon repair must be performed definitely for low-energy short firearm injuries but very carefully for high-energy injuries. Given these findings, we suggest that the treatment option should be determined based not only on the bullet type alone but also on other clinical findings. PMID:26874437

Hormonal, metabolic, and cardiorespiratory responses of young and adult athletes to a single session of high-intensity cycle exercise.

PubMed

Engel, Florian; Härtel, Sascha; Wagner, Matthias Oliver; Strahler, Jana; Bös, Klaus; Sperlich, Billy

2014-11-01

This study aimed to determine the effects of a single high-intensity interval training (HIIT) session on salivary cortisol (SC) levels, physiological responses, and performance in trained boys and men. Twenty-three boys (11.5 ± 0.8 years) and 25 men (29.7 ± 4.6 years) performed HIIT (4 consecutive Wingate Anaerobic Tests). SC in boys and men increased after HIIT from 5.55 ± 3.3 nmol/l to 15.13 ± 9.7 nmol/l (+173%) and from 7.07 ± 4.7 nmol/l to 19.19 ± 12.7 nmol/l (+171%), respectively (p < .01). Pretest SC as well as posttest changes were comparable in both groups (both p < .01). Peak blood lactate concentration was significantly lower in boys (12.6 ± 3.5 mmol/l) than in men (16.3 ± 3.1 mmol/l; p < .01). Throughout the HIIT, mean heart rates in boys were higher (p < .001) but relative peak oxygen uptake (ml·min-1·kg-1; p < .05) and performance were lower (p < .001) in boys than in men. HIIT in young athletes is associated with a higher activation of the hormonal stress axis than other types of exercise regimes as described in the literature. This study is the first to show a pronounced SC increase to HIIT in trained boys accompanied by elevated levels of blood lactate concentrations and heart rate suggesting a high cardio-respiratory, metabolic, and hormonal response to HIIT in 11-year-old boys.

A Selected Immunohistochemical Panel Aids in Differential Diagnosis and Prognostic Stratification of Subtypes of High-grade Endometrial Carcinoma: A Clinicopathologic and Immunohistochemical Study at a Single Institution.

PubMed

Taskin, Orhun Çiğ; Onder, Semen; Topuz, Samet; Sozen, Hamdullah; Sen, Fatma; Ilhan, Ridvan; Yavuz, Ekrem

This study aimed to investigate whether a selected immunohistochemical panel (estrogen receptor, p53, ARID1A, PPP2R1A, HNF-1β) could contribute to the diagnostic process of high-grade endometrial carcinomas (HG-ECs). We also aimed to analyze the correlation of these immunohistochemical results with several morphologic variables and survival data. After revising the diagnosis of 78 HG-ECs, immunohistochemical analysis was performed for each case. After immunohistochemical analysis, a specific diagnosis of prototypic HG-EC was established in most of the cases that were uncertain due to morphologic ambiguity. In the univariate analysis, older patient age, type II morphology, undifferentiated carcinoma and carcinosarcoma type of histology, altered p53 immunostaining, strong membranous staining of PPP2R1A, presence of lymphovascular invasion in serous carcinoma, and microcystic, elongated, and fragmented-type infiltration pattern in endometrioid carcinoma were significantly related to poor prognosis. In the multivariate analysis, only older patient age and carcinosarcoma or undifferentiated/dedifferentiated carcinoma type histology were found to be significantly poor prognostic factors (P=0.011), whereas advanced FIGO stage and type II histology were found to be correlated with poor prognosis, but did not reach statistical significance. We suggest that immunohistochemistry should be used in the differential diagnosis of HG-ECs, especially those with ambiguous morphology. Markers used in this study made a valuable contribution to the diagnostic process as well as prediction of prognosis.

High prevalence of human papillomavirus infection in American Indian women of the Northern Plains

PubMed Central

Bell, Maria C.; Schmidt-Grimminger, Delf; Patrick, Sarah; Ryschon, Tim; Linz, Laurie; Chauhan, Subhash C.

2008-01-01

Objectives Cervical cancer is the leading gynecological malignancy worldwide, and the incidence of this disease is very high in American Indian women. Infection with the Human Papillomavirus (HPV) is responsible for more than 95% of cervical squamous carcinomas. Therefore, the main objective of this study was to analyze oncogenic HPV infections in American Indian women residing in the Northern Plains. Methods Cervical samples were collected from 287 women attending a Northern Plains American Indian reservation outpatient clinic. DNA was extracted from the cervical samples and HPV specific DNA were amplified by polymerase chain reaction (PCR) using the L1 consensus primer sets. The PCR products were hybridized with the Roche HPV Line Blot assay for HPV genotyping to detect 27 different low and high-risk HPV genotypes. The chi-square test was performed for statistical analysis of the HPV infection and cytology diagnosis data. Results Of the total 287 patients, 61 women (21.25%) tested positive for HPV infection. Among all HPV-positive women, 41 (67.2%) were infected with high-risk HPV types. Of the HPV infected women, 41% presented with multiple HPV genotypes. Additionally, of the women infected with oncogenic HPV types, 20 (48.7%) were infected with HPV 16 and 18 and the remaining 21 (51.3%) were infected with other oncogenic types (i.e., HPV59, 39, 73). Women infected with oncogenic HPV types had significantly higher (p=0.001) abnormal Papanicolaou smear tests (Pap test) compared to women who were either HPV negative or positive for non-oncogenic HPV types. The incidence of HPV infection was inversely correlated (p<0.05) with the age of the patients, but there was no correlation (p=0.33) with seasonal variation. Conclusions In this study, we observed a high prevalence of HPV infection in American Indian women residing on Northern Plains Reservations. In addition, a significant proportion of the oncogenic HPV infections were other than HPV16 and 18. PMID:17659767

Low physical activity as a key differentiating factor in the potential high-risk profile for depressive symptoms in older adults.

PubMed

Holmquist, Sofie; Mattsson, Sabina; Schele, Ingrid; Nordström, Peter; Nordström, Anna

2017-09-01

The identification of potential high-risk groups for depression is of importance. The purpose of the present study was to identify high-risk profiles for depressive symptoms in older individuals, with a focus on functional performance. The population-based Healthy Ageing Initiative included 2,084 community-dwelling individuals (49% women) aged 70. Explorative cluster analysis was used to group participants according to functional performance level, using measures of basic mobility skills, gait variability, and grip strength. Intercluster differences in depressive symptoms (measured by the Geriatric Depression Scale [GDS]-15), physical activity (PA; measured objectively with the ActiGraph GT3X+), and a rich set of covariates were examined. The cluster analysis yielded a seven-cluster solution. One potential high-risk cluster was identified, with overrepresentation of individuals with GDS scores >5 (15.1 vs. 2.7% expected; relative risk = 6.99, P < .001); the prevalence of depressive symptoms was significantly lower in the other clusters (all P < .01). The potential high-risk cluster had significant overrepresentations of obese individuals (39.7 vs. 17.4% expected) and those with type 2 diabetes (24.7 vs. 8.5% expected), and underrepresentation of individuals who fulfilled the World Health Organization's PA recommendations (15.6 vs. 59.1% expected; all P < .01), as well as low levels of functional performance. The present study provided a potential high-risk profile for depressive symptoms among elderly community-dwelling individuals, which included low levels functional performance combined with low levels of PA. Including PA in medical screening of the elderly may aid in identification of potential high-risk individuals for depressive symptoms. © 2017 Wiley Periodicals, Inc.

Ambipolar Graphene-Quantum Dot Hybrid Vertical Photodetector with a Graphene Electrode.

PubMed

Che, Yongli; Zhang, Yating; Cao, Xiaolong; Zhang, Haiting; Song, Xiaoxian; Cao, Mingxuan; Yu, Yu; Dai, Haitao; Yang, Junbo; Zhang, Guizhong; Yao, Jianquan

2017-09-20

A strategy to fabricate an ambipolar near-infrared vertical photodetector (VPD) by sandwiching a photoactive material as a channel film between the bottom graphene and top metal electrodes was developed. The channel length in the vertical architecture was determined by the channel layer thickness, which can provide an ultrashort channel length without the need for a high-precision manufacturing process. The performance of VPDs with two types of semiconductor layers, a graphene-PbS quantum dot hybrid (GQDH) and PbS quantum dots (QDs), was measured. The GQDH VPD showed better photoelectric properties than the QD VPD because of the high mobility of graphene doped in the channel. The GQDH VPD exhibited excellent photoresponse properties with a responsivity of 1.6 × 10 4 A/W in the p-type regime and a fast response speed with a rise time of 8 ms. The simple manufacture and the promising photoresponse of the GQDH VPDs reveal that an easy and effective way to fabricate high-performance ambipolar photodetectors was developed.

Polymorphism of the bivalent metal vanadates MeV 2O 6 ( Me = Mg, Ca, Mn, Co, Ni, Cu, Zn, Cd)

NASA Astrophysics Data System (ADS)

Mocała, Krzysztof; Ziółkowski, Jacek

1987-08-01

Based on the literature data, our former findings and additional DTA and high-temperature X-ray studies performed for CdV 2O 6, MgV 2O 6, and MnV 2O 6, a consistent scheme of the phase transformations of the MeV 2O 6 ( Me = Mg, Ca, Mn, Co, Ni, Cu, Zn, Cd) metavanadates is constructed at normal pressure between room temperature and melting points. Three types of structures exist for the considered compounds: brannerite type (B), pseudobrannerite type (P), and NiV 2O 6 type (N). The following phase transformations have been observed: Me = Mg, B → P at 535°C; Me = Mn, B → P at 540°C; Me = Co, N → B at 660°C; Me = Cu, B (with triclinic distortion) → B at 625°C (secondary order); and Me = Cd, B → P at 170°. CaV 2O 6P, NiV 2O 6N, and ZnV 2O 6B exist in unique form in the entire temperature range. P-form seems to be favored by Me of larger ionic radii. N-form seems to appear at a peculiar d-shell structure and small Me size. Preliminary explanation of the dependence of the structure type on Me size is offered. New X-ray data are given for CdV 2O 6B, CdV 2O 6P, MgV 2O 6B, MgV 2O 6P, and MnV 2O 6P.

Phosphorous doped p-type MoS2 polycrystalline thin films via direct sulfurization of Mo film

NASA Astrophysics Data System (ADS)

Momose, Tomohiro; Nakamura, Atsushi; Daniel, Moraru; Shimomura, Masaru

2018-02-01

We report on the successful synthesis of a p-type, substitutional doping at S-site, MoS2 thin film using Phosphorous (P) as the dopant. MoS2 thin films were directly sulfurized for molybdenum films by chemical vapor deposition technique. Undoped MoS2 film showed n-type behavior and P doped samples showed p-type behavior by Hall-effect measurements in a van der Pauw (vdP) configuration of 10×10 mm2 area samples and showed ohmic behavior between the silver paste contacts. The donor and the acceptor concentration were detected to be ˜2.6×1015 cm-3 and ˜1.0×1019 cm-3, respectively. Hall-effect mobility was 61.7 cm2V-1s-1 for undoped and varied in the range of 15.5 ˜ 0.5 cm2V-1s-1 with P supply rate. However, the performance of field-effect transistors (FETs) declined by double Schottky barrier contacts where the region between Ni electrodes on the source/drain contact and the MoS2 back-gate cannot be depleted and behaves as a 3D material when used in transistor geometry, resulting in poor on/off ratio. Nevertheless, the FETs exhibit hole transport and the field-effect mobility showed values as high as the Hall-effect mobility, 76 cm2V-1s-1 in undoped MoS2 with p-type behavior and 43 cm2V-1s-1 for MoS2:P. Our findings provide important insights into the doping constraints for transition metal dichalcogenides.

The influence of diets containing either conventional corn, conventional corn with choice white grease, high oil corn, or high oil high oleic corn on belly/bacon quality.

PubMed

Rentfrow, G; Sauber, T E; Allee, G L; Berg, E P

2003-08-01

The objectives of this study were to evaluate diets possessing different fatty acid profiles (as influenced by corn type) with regard to fatty acid profile and firmness of pork bellies. Crossbred barrows (n=196) were fed one of four corn-based diets consisting of conventional corn (CONV), CONV with choice white grease (CWG), high oil corn (HOC), or high oleic, high oil corn (HOHOC). Following 98 days on test, two animals representing the average pen weight (118 kg) were selected for harvest (n=56). A 50-g fat sample was removed from each belly for fatty acid profile analysis. Lateral and vertical flex tests were performed to determine belly firmness. Bellies were pumped and cooked according to a commercial protocol. Total saturated fatty acids increased (P<0.001) and total unsaturated fatty acids decreased (P<0.05) when CWG was added to the CONV diet or when HOC or HOHOC were substituted for CONV corn. Pigs fed CONV corn had firmer bellies, while those fed HOC were softer. No differences were observed across treatment for percentage pump retention, smokehouse yield, or slicing yield (P>0.05). Based on the results of this study, corn type influences fatty acid profile, and belly firmness, but does not affect pump retention, or slicing yields.

Different DNA damage and cell cycle checkpoint control in low- and high-risk human papillomavirus infections of the vulva.

PubMed

Santegoets, Lindy A M; van Baars, Romy; Terlou, Annelinde; Heijmans-Antonissen, Claudia; Swagemakers, Sigrid M A; van der Spek, Peter J; Ewing, Patricia C; van Beurden, Marc; van der Meijden, Willem I; Helmerhorst, Theo J M; Blok, Leen J

2012-06-15

Human papillomavirus (HPV) infections may result in benign hyperplasia, caused by low-risk HPV types, or (pre)malignant lesions caused by high-risk HPV types. The molecular basis of this difference in malignant potential is not completely understood. Here, we performed gene profiling of different HPV infected vulvar tissues (condylomata acuminata (n = 5), usual type vulvar intraepithelial neoplasia (uVIN) (n = 9)) and control samples (n = 14) using Affymetrix Human U133A plus 2 GeneChips. Data were analyzed using OmniViz®, Partek® and Ingenuity® Software. Results were validated by real-time RT-PCR and immunostaining. Although similarities were observed between gene expression profiles of low- and high-risk HPV infected tissues (e.g., absence of estrogen receptor in condylomata and uVIN), high-risk HPV infected tissues showed more proliferation and displayed more DNA damage than tissues infected with low-risk HPV. These observations were confirmed by differential regulation of cell cycle checkpoints and by increased expression of DNA damage-biomarkers p53 and γH2AX. Furthermore, FANCA, FANCD2, BRCA1 and RAD51, key players in the DNA damage response, were significantly upregulated (p < 0.05). In addition, we compared our results with publicly available gene expression profiles of various other HPV-induced cancers (vulva, cervix and head-and-neck). This showed p16(INK4a) was the most significant marker to detect a high-risk HPV infection, but no other markers could be found. In conclusion, this study provides insight into the molecular basis of low- and high-risk HPV infections and indicates two main pathways (cell cycle and DNA damage response) that are much stronger affected by high-risk HPV as compared to low-risk HPV. Copyright © 2011 UICC.

Are we all doing it wrong? Influence of stripping and cleaving methods of laser fibers on laser lithotripsy performance.

PubMed

Kronenberg, Peter; Traxer, Olivier

2015-03-01

We assessed whether stripping and cleaving the laser fiber tip with specialized tools, namely laser fiber strippers, or ceramic or metal scissors, would influence lithotripsy performance. Laser fiber tips were stripped with a specialized laser fiber stripper or remained coated. The tips were then cleaved with metal or ceramic scissors. Laser lithotripsy experiments were performed with the 4 fiber tip combinations using an automated laser fragmentation testing system with artificial stones made of plaster of Paris or BegoStone Plus (Bego, Lincoln, Rhode Island). High frequency-low pulse energy (20 Hz and 0.5 J) and low frequency-high pulse energy (5 Hz and 2.0 J) settings were used for 30 seconds. Fissure width, depth and volume, and laser fiber tip photos were analyzed. Coated laser fiber tips always achieved significantly higher ablation volumes (sometimes greater than 50%) than stripped laser fiber tips (p <0.00001) regardless of cleaving scissor type, stone material or lithotripter setting. Coated fiber tips cleaved with metal scissors ablated as well as those cleaved with ceramic scissors (p = 0.16). However, stripped fibers were much less ablative when they were cut with metal scissors compared to ceramic scissors (p <0.00001). Harder stone material decreased ablation volume (p <0.00001). Low frequency-high pulse energy settings were an average of 3 times more ablative than high frequency-low pulse energy settings (p <0.00001). Stripping the fibers, a harder stone material and low frequency-high pulse energy settings were associated with increased fiber tip degradation. Coated laser fibers provided better lithotripsy performance and metal scissors were as good as ceramic scissors to cleave coated fibers. This knowledge may improve and simplify the way that laser lithotripsy procedures are done worldwide. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Low-frequency noise reduction in vertical MOSFETs having tunable threshold voltage fabricated with 60 nm CMOS technology on 300 mm wafer process

NASA Astrophysics Data System (ADS)

Imamoto, Takuya; Ma, Yitao; Muraguchi, Masakazu; Endoh, Tetsuo

2015-04-01

In this paper, DC and low-frequency noise (LFN) characteristics have been investigated with actual measurement data in both n- and p-type vertical MOSFETs (V-MOSFETs) for the first time. The V-MOSFETs which was fabricated on 300 mm bulk silicon wafer process have realized excellent DC performance and a significant reduction of flicker (1/f) noise. The measurement results show that the fabricated V-MOSFETs with 60 nm silicon pillar and 100 nm gate length achieve excellent steep sub-threshold swing (69 mV/decade for n-type and 66 mV/decade for p-type), good on-current (281 µA/µm for n-type 149 µA/µm for p-type), low off-leakage current (28.1 pA/µm for n-type and 79.6 pA/µm for p-type), and excellent on-off ratio (1 × 107 for n-type and 2 × 106 for p-type). In addition, it is demonstrated that our fabricated V-MOSFETs can control the threshold voltage (Vth) by changing the channel doping condition, which is the useful and low-cost technique as it has been widely used in the conventional bulk planar MOSFET. This result indicates that V-MOSFETs can control Vth more finely and flexibly by the combined the use of the doping technique with other techniques such as work function engineering of metal-gate. Moreover, it is also shown that V-MOSFETs can suppress 1/f noise (L\\text{gate}WS\\text{Id}/I\\text{d}2 of 10-13-10-11 µm2/Hz for n-type and 10-12-10-10 µm2/Hz for p-type) to one or two order lower level than previously reported nanowire type MOSFET, FinFET, Tri-Gate, and planar MOSFETs. The results have also proved that both DC and 1/f noise performances are independent from the bias voltage which is applied to substrate or well layer. Therefore, it is verified that V-MOSFETs can eliminate the effects from substrate or well layer, which always adversely affects the circuit performances due to this serial connection.

Impaired fat oxidation after a single high-fat meal in insulin-sensitive nondiabetic individuals with a family history of type 2 diabetes.

PubMed

Heilbronn, Leonie K; Gregersen, Søren; Shirkhedkar, Deepali; Hu, Dachun; Campbell, Lesley V

2007-08-01

Individuals with insulin resistance and type 2 diabetes have an impaired ability to switch appropriately between carbohydrate and fatty acid oxidation. However, whether this is a cause or consequence of insulin resistance is unclear, and the mechanism(s) involved in this response is not completely elucidated. Whole-body fat oxidation and transcriptional regulation of genes involved in lipid metabolism in skeletal muscle were measured after a prolonged fast and after consumption of either high-fat (76%) or high-carbohydrate (76%) meals in individuals with no family history of type 2 diabetes (control, n = 8) and in age- and fatness-matched individuals with a strong family history of type 2 diabetes (n = 9). Vastus lateralis muscle biopsies were performed before and 3 h after each meal. Insulin sensitivity and fasting measures of fat oxidation were not different between groups. However, subjects with a family history of type 2 diabetes had an impaired ability to increase fatty acid oxidation in response to the high-fat meal (P < 0.05). This was related to impaired activation of genes involved in lipid metabolism, including those for peroxisome proliferator-activated receptor coactivator-1alpha (PGC1alpha) and fatty acid translocase (FAT)/CD36 (P < 0.05). Of interest, adiponectin receptor-1 expression decreased 23% after the high-fat meal in both groups, but it was not changed after the high-carbohydrate meal. In conclusion, an impaired ability to increase fatty acid oxidation precedes the development of insulin resistance in genetically susceptible individuals. PGC1alpha and FAT/CD36 are likely candidates in mediating this response.

Direct Photolithography on Molecular Crystals for High Performance Organic Optoelectronic Devices.

PubMed

Yao, Yifan; Zhang, Lei; Leydecker, Tim; Samorì, Paolo

2018-05-23

Organic crystals are generated via the bottom-up self-assembly of molecular building blocks which are held together through weak noncovalent interactions. Although they revealed extraordinary charge transport characteristics, their labile nature represents a major drawback toward their integration in optoelectronic devices when the use of sophisticated patterning techniques is required. Here we have devised a radically new method to enable the use of photolithography directly on molecular crystals, with a spatial resolution below 300 nm, thereby allowing the precise wiring up of multiple crystals on demand. Two archetypal organic crystals, i.e., p-type 2,7-diphenyl[1]benzothieno[3,2- b][1]benzothiophene (Dph-BTBT) nanoflakes and n-type N, N'-dioctyl-3,4,9,10-perylenedicarboximide (PTCDI-C8) nanowires, have been exploited as active materials to realize high-performance top-contact organic field-effect transistors (OFETs), inverter and p-n heterojunction photovoltaic devices supported on plastic substrate. The compatibility of our direct photolithography technique with organic molecular crystals is key for exploiting the full potential of organic electronics for sophisticated large-area devices and logic circuitries, thus paving the way toward novel applications in plastic (opto)electronics.

Strained silicon based complementary tunnel-FETs: Steep slope switches for energy efficient electronics

NASA Astrophysics Data System (ADS)

Knoll, L.; Richter, S.; Nichau, A.; Trellenkamp, S.; Schäfer, A.; Wirths, S.; Blaeser, S.; Buca, D.; Bourdelle, K. K.; Zhao, Q.-T.; Mantl, S.

2014-08-01

Electrical characteristics of silicon nanowire tunnel field effect transistors (TFETs) are presented and benchmarked versus other concepts. Particular emphasis is placed on the band to band tunneling (BTBT) junctions, the functional core of the device. Dopant segregation from ion implanted ultrathin silicide contacts is proved as a viable method to achieve steep tunneling junctions. This reduces defect generation by direct implantation into the junction and thus minimizes the risk of trap assisted tunneling. The method is applied to strained silicon, specifically to nanowire array transistors, enabling the realization of n-type and p-type TFETs with fairly high currents and complementary TFET inverters with sharp transitions and good static gain, even at very low drain voltages of VDD = 0.2 V. These achievements suggest a considerable potential of TFETs for ultralow power applications. Gate-all-around Si nanowire array p-type TFETs have been fabricated to demonstrate the impact of electrostatic control on the device performance. A high on-current of 78 μA/μm at VD = VG = 1.1 V is obtained.

A complementary organic inverter of porphyrazine thin films: low-voltage operation using ionic liquid gate dielectrics.

PubMed

Fujimoto, Takuya; Miyoshi, Yasuhito; Matsushita, Michio M; Awaga, Kunio

2011-05-28

We studied a complementary organic inverter consisting of a p-type semiconductor, metal-free phthalocyanine (H(2)Pc), and an n-type semiconductor, tetrakis(thiadiazole)porphyrazine (H(2)TTDPz), operated through the ionic-liquid gate dielectrics of N,N-diethyl-N-methyl(2-methoxyethyl)ammonium bis(trifluoromethylsulfonyl)imide (DEME-TFSI). This organic inverter exhibits high performance with a very low operation voltage below 1.0 V and a dynamic response up to 20 Hz. © The Royal Society of Chemistry 2011

Long-term N-acetylcysteine and L-arginine administration reduces endothelial activation and systolic blood pressure in hypertensive patients with type 2 diabetes.

PubMed

Martina, Valentino; Masha, Andi; Gigliardi, Valentina Ramella; Brocato, Loredana; Manzato, Enzo; Berchio, Arrigo; Massarenti, Paola; Settanni, Fabio; Della Casa, Lara; Bergamini, Stefania; Iannone, Anna

2008-05-01

Reactive oxygen and nitric oxide (NO) have recently been considered to be involved in the cardiovascular complications of patients with type 2 diabetes, as NO is thought to lose its beneficial physiological effects in the presence of oxygen radicals. For this reason, we tested the effects of l-arginine (ARG) and N-acetylcysteine (NAC) administration in increasing NO bioavailability by reducing free radical formation. A double-blind study was performed on 24 male patients with type 2 diabetes and hypertension divided into two groups of 12 patients that randomly received either an oral supplementation of placebo or NAC + ARG for 6 months. The NAC + ARG treatment caused a reduction of both systolic (P < 0.05) and diastolic (P < 0.05) mean arterial blood pressure, total cholesterol (P < 0.01), LDL cholesterol (P < 0.005), oxidized LDL (P < 0.05), high-sensitive C-reactive protein (P < 0.05), intracellular adhesion molecule (P < 0.05), vascular cell adhesion molecule (P < 0.01), nitrotyrosine (P < 0.01), fibrinogen (P < 0.01), and plasminogen activator inhibitor-1 (P < 0.05), and an improvement of the intima-media thickness during endothelial postischemic vasodilation (P < 0.02). HDL cholesterol increased (P < 0.05). No changes in other parameters studied were observed. NAC + ARG administration seems to be a potential well-tolerated antiatherogenic therapy because it improves endothelial function in hypertensive patients with type 2 diabetes by improving NO bioavailability via reduction of oxidative stress and increase of NO production. Our study's results give prominence to its potential use in primary and secondary cardiovascular prevention in these patients.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fleurial, J.; Caillat, T.; Borshchevsky, A.

Based on literature data and experimental findings at the Jet Propulsion Laboratory (JPL), semiconductors with the skutterudite structure TPn{sub 3} (where T is a transition metal element such as Co, Rh, Ir, Ni, and Pd, and Pn is a pnicogen element such as P, As, and Sb) possess attractive characteristics and show a good potential for high {ital ZT} values. The high degree of covalency results in high mobility and low electrical resistivity values while a relatively complex 32 atom unit cell results in a reasonably low thermal conductivity. Both {ital n}-type and {ital p}-type electrical conductivity samples have beenmore » obtained. Room temperature Seebeck coefficient values up to 200 {mu}VK{sup {minus}1} for {ital p}-type and up to {minus}600 {mu}VK{sup {minus}1} for {ital n}-type have also been measured on several of these materials. In addition, the large number of isostructural compounds, solid solutions and related phases offer many possibilities for optimization of the transport properties to a specific temperature range of thermoelectric applications. By replacing the transition metal or the pnicogen atom by two of its neighboring elements and ensuring that the number of valence electrons is retained, many ternary phases can be successfully derived from the original CoAs{sub 3} skutterudite structure. Some of these materials were found to have substantially lower thermal conductivities compared to those of the binary compounds. The composition, band gap and doping level can be tailored to achieve maximum performance. An overview of the results obtained to date is provided and our approach to achieving high {ital ZT} materials are discussed in this paper. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.« less

Graphene-based copper oxide thin film nanostructures as high-efficiency photocathode for p-type dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Kilic, Bayram; Turkdogan, Sunay; Astam, Aykut; Baran, Sümeyra Seniha; Asgin, Mansur; Cebeci, Hulya; Urk, Deniz

2017-10-01

Graphene-based p-type dye-sensitized solar cells (p-DSSCs) have been proposed and fabricated using copper oxide urchin-like nanostructures (COUN) as photocathode with an FeS2 counter electrode (CE). COUN composed of Cu2O core sphere and CuO shell nanorods with overall diameters of 2 to 4 μm were grown by a simple hydrothermal method with self-assemble nucleation. It was figured out that the formation of copper oxide core/shell structures could be adjusted by an ammonia additive leading to pH change of the precursor solution. In addition to a photocathode, we also demonstrated FeS2 thin films as an efficient CE material alternative to the conventional Pt CEs in DSSCs. FeS2 nanostructures, with diameters of 50 to 80 nm, were synthesized by a similar hydrothermal approach. FeS2 nanostructures are demonstrated to be an outstanding CE material in p-DSSCs. We report graphene/COUN as photocathode and Pt/FeS2 as CE in p-DSSCs, and results show that the synergetic combination of electrodes in each side (increased interconnectivity between COUN and graphene layer, high surface area, and high catalytic activity of FeS2) increased the power conversion efficiency from 1.56% to 3.14%. The excellent performances of COUN and FeS2 thin film in working and CEs, respectively, make them unique choices among the various photocathode and CE materials studied.

Shared susceptibility loci at 2q33 region for lung and esophageal cancers in high-incidence areas of esophageal cancer in northern China

PubMed Central

Song, Xin; Hu, Shou Jia; Lv, Shuang; Cheng, Rang; Zhang, Tang Juan; Han, Xue Na; Ren, Jing Li; Qi, Yi Jun

2017-01-01

Background Cancers from lung and esophagus are the leading causes of cancer-related deaths in China and share many similarities in terms of histological type, risk factors and genetic variants. Recent genome-wide association studies (GWAS) in Chinese esophageal cancer patients have demonstrated six high-risk candidate single nucleotide polymorphisms (SNPs). Thus, the present study aimed to determine the risk of these SNPs predisposing to lung cancer in Chinese population. Methods A total of 1170 lung cancer patients and 1530 normal subjects were enrolled in this study from high-incidence areas for esophageal cancer in Henan, northern China. Five milliliters of blood were collected from all subjects for genotyping. Genotyping of 20 high-risk SNP loci identified from genome-wide association studies (GWAS) on esophageal, lung and gastric cancers was performed using TaqMan allelic discrimination assays. Polymorphisms were examined for deviation from Hardy-Weinberg equilibrium (HWE) using Х2 test. Bonferroni correction was performed to correct the statistical significance of 20 SNPs with the risk of lung cancer. The Pearson’s Х2 test was used to compare the distributions of gender, TNM stage, histopathological type, smoking and family history by lung susceptibility genotypes. Kaplan-Meier and Cox regression analyses were carried out to evaluate the associations between genetic variants and overall survival. Results Four of the 20 SNPs identified as high-risk SNPs in Chinese esophageal cancer showed increased risk for Chinese lung cancer, which included rs3769823 (OR = 1.26; 95% CI = 1.107–1.509; P = 0.02), rs10931936 (OR = 1.283; 95% CI = 1.100–1.495; P = 0.04), rs2244438 (OR = 1.294; 95% CI = 1.098–1.525; P = 0.04) and rs13016963 (OR = 1.268; 95% CI = 1.089–1.447; P = 0.04). All these SNPs were located at 2q33 region harboringgenes of CASP8, ALS2CR12 and TRAK2. However, none of these susceptibility SNPs was observed to be significantly associated with gender, TNM stage, histopathological type, smoking, family history and overall survival. Conclusions The present study identified four high-risk SNPs at 2q33 locus for Chinese lung cancer and demonstrated the shared susceptibility loci at 2q33 region for Chinese lung and esophageal cancers. PMID:28542283

Shared susceptibility loci at 2q33 region for lung and esophageal cancers in high-incidence areas of esophageal cancer in northern China.

PubMed

Zhao, Xue Ke; Mao, Yi Min; Meng, Hui; Song, Xin; Hu, Shou Jia; Lv, Shuang; Cheng, Rang; Zhang, Tang Juan; Han, Xue Na; Ren, Jing Li; Qi, Yi Jun; Wang, Li Dong

2017-01-01

Cancers from lung and esophagus are the leading causes of cancer-related deaths in China and share many similarities in terms of histological type, risk factors and genetic variants. Recent genome-wide association studies (GWAS) in Chinese esophageal cancer patients have demonstrated six high-risk candidate single nucleotide polymorphisms (SNPs). Thus, the present study aimed to determine the risk of these SNPs predisposing to lung cancer in Chinese population. A total of 1170 lung cancer patients and 1530 normal subjects were enrolled in this study from high-incidence areas for esophageal cancer in Henan, northern China. Five milliliters of blood were collected from all subjects for genotyping. Genotyping of 20 high-risk SNP loci identified from genome-wide association studies (GWAS) on esophageal, lung and gastric cancers was performed using TaqMan allelic discrimination assays. Polymorphisms were examined for deviation from Hardy-Weinberg equilibrium (HWE) using Х2 test. Bonferroni correction was performed to correct the statistical significance of 20 SNPs with the risk of lung cancer. The Pearson's Х2 test was used to compare the distributions of gender, TNM stage, histopathological type, smoking and family history by lung susceptibility genotypes. Kaplan-Meier and Cox regression analyses were carried out to evaluate the associations between genetic variants and overall survival. Four of the 20 SNPs identified as high-risk SNPs in Chinese esophageal cancer showed increased risk for Chinese lung cancer, which included rs3769823 (OR = 1.26; 95% CI = 1.107-1.509; P = 0.02), rs10931936 (OR = 1.283; 95% CI = 1.100-1.495; P = 0.04), rs2244438 (OR = 1.294; 95% CI = 1.098-1.525; P = 0.04) and rs13016963 (OR = 1.268; 95% CI = 1.089-1.447; P = 0.04). All these SNPs were located at 2q33 region harboringgenes of CASP8, ALS2CR12 and TRAK2. However, none of these susceptibility SNPs was observed to be significantly associated with gender, TNM stage, histopathological type, smoking, family history and overall survival. The present study identified four high-risk SNPs at 2q33 locus for Chinese lung cancer and demonstrated the shared susceptibility loci at 2q33 region for Chinese lung and esophageal cancers.

Accuracy of noncycloplegic retinoscopy, retinomax autorefractor, and SureSight vision screener for detecting significant refractive errors.

PubMed

Kulp, Marjean Taylor; Ying, Gui-Shuang; Huang, Jiayan; Maguire, Maureen; Quinn, Graham; Ciner, Elise B; Cyert, Lynn A; Orel-Bixler, Deborah A; Moore, Bruce D

2014-03-06

To evaluate, by receiver operating characteristic (ROC) analysis, the ability of noncycloplegic retinoscopy (NCR), Retinomax Autorefractor (Retinomax), and SureSight Vision Screener (SureSight) to detect significant refractive errors (RE) among preschoolers. Refraction results of eye care professionals using NCR, Retinomax, and SureSight (n = 2588) and of nurse and lay screeners using Retinomax and SureSight (n = 1452) were compared with masked cycloplegic retinoscopy results. Significant RE was defined as hyperopia greater than +3.25 diopters (D), myopia greater than 2.00 D, astigmatism greater than 1.50 D, and anisometropia greater than 1.00 D interocular difference in hyperopia, greater than 3.00 D interocular difference in myopia, or greater than 1.50 D interocular difference in astigmatism. The ability of each screening test to identify presence, type, and/or severity of significant RE was summarized by the area under the ROC curve (AUC) and calculated from weighted logistic regression models. For detection of each type of significant RE, AUC of each test was high; AUC was better for detecting the most severe levels of RE than for all REs considered important to detect (AUC 0.97-1.00 vs. 0.92-0.93). The area under the curve of each screening test was high for myopia (AUC 0.97-0.99). Noncycloplegic retinoscopy and Retinomax performed better than SureSight for hyperopia (AUC 0.92-0.99 and 0.90-0.98 vs. 0.85-0.94, P ≤ 0.02), Retinomax performed better than NCR for astigmatism greater than 1.50 D (AUC 0.95 vs. 0.90, P = 0.01), and SureSight performed better than Retinomax for anisometropia (AUC 0.85-1.00 vs. 0.76-0.96, P ≤ 0.07). Performance was similar for nurse and lay screeners in detecting any significant RE (AUC 0.92-1.00 vs. 0.92-0.99). Each test had a very high discriminatory power for detecting children with any significant RE.

In-Situ Grown P-N Junctions in MERCURY(1-X) Cadmium(x) Telluride for IR Detectors.

NASA Astrophysics Data System (ADS)

Rao, Vithal Rajaram

In-situ grown p-n junctions in mercury cadmium telluride (Hg_{1-x}Cd _{x}Te with x between 0.2-0.3) were fabricated and characterized in this study. Fabrication of these junctions involved the growth of p-n structures at 370^circC on CdTe substrates by Organometallic Vapor Phase Epitaxy. P-type doping with arsenic was achieved by using tertiarybutylarsine as the precursor. N-type doping was obtained either with indium, using trimethylindium as the precursor or by leaving the layer undoped. These p-n structures were processed to fabricate photodiodes. Their electrical performance was evaluated and conclusions regarding current mechanisms which determine their behavior were drawn. By varying the Hg pressure between 0.07-0.13 atm, p-type doping level in the 10^{16 }/cm^3-rm2times10 ^{17}/cm^3 range was achieved. At higher values of Hg pressure, the arsenic doping level in the layer increased significantly. This is possibly due to an increase in Te vacancies, allowing arsenic to occupy more group VI sites where they behave as acceptors. The activation efficiency of arsenic in the layers was measured to be equal to 50%. A high temperature anneal at 415 ^circC for 15 minutes did not result in any increase in the activation efficiency, possibly indicating the presence of stable As-complexes in the layer. Growth of p^+n structures was carried out in a single run. The acceptor concentration in the p-type cap layer was 5-rm10times10 ^{16}/cm^3. Indium doped n-type base layers had a carrier concentration of 1- rm2times10^{16}/cm^3 , while undoped layers had a n-type background carrier concentration of 4-rm6times10^ {14}/cm^3. The cap layer was 3 μm thick with x = 0.30, while the base layer was 8mum thick with x = 0.26. Under the growth conditions, arsenic showed a diffusion coefficient of rm2times10 ^{13}cm^2/s, which was higher than the interdiffusion coefficient of the alloy junction. This resulted in placement of the p-n junction in the lower bandgap base layer, which is necessary for high quantum efficiency devices. Photodiodes showed a cutoff wavelength of 7.5 mum, which correlates with the alloy composition of the base layer. Measured R_0 A of these diodes varied between 1-100 ohm-cm ^2. In the lower R_0A diodes, reverse bias was dominated by surface currents, possibly due to degradation of the passivating layer. Diodes with higher R_0A showed under reverse bias that trap assisted tunneling current dominated their performance. The origin of these traps is process related and could correspond to the presence of inactivated arsenic close to the p-n junction. Forward bias was dominated by diffusion and recombination currents, while the presence of additional leakage currents was evident.

Photo-catalytic Degradation and Sorption of Radio-cobalt from EDTA-Co Complexes Using Manganese Oxide Materials - 12220

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koivula, Risto; Harjula, Risto; Tusa, Esko

2012-07-01

The synthesised cryptomelane-type α-MnO{sub 2} was tested for its Co-57 uptake properties in UV-photo-reactor filled with 10 μM Co-EDTA solution with a background of 10 mM NaNO{sub 3}. High cobalt uptake of 96% was observed after 1 hour of UV irradiation. As for comparison, a well-known TiO{sub 2} (Degussa P25) was tested as reference material that showed about 92% cobalt uptake after six hours of irradiation in identical experiment conditions. It was also noted that the cobalt uptake on cryptomelane with out UV irradiation was modest, only about 10%. Decreasing the pH of the Co-EDTA solution had severe effects onmore » the cobalt uptake mainly due to the rather high point of zero charge of the MnO{sub 2} surface (pzc at pH ∼4.5). Modifying the synthesis procedure we were able to produce a material that functioned well even in solution of pH 3 giving cobalt uptake of almost 99%. The known properties, catalytic and ion exchange, of manganese oxides were simultaneously used for the separation of EDTA complexed Co-57. Tunnel structured cryptomelane -type showed very fast and efficient Co uptake properties outperforming the well known and widely used Degussa P25 TiO{sub 2} in both counts. The layered structured manganese oxide, birnessite, reached also as high Co removal level as the reference material Degussa did but the reaction rate was considerably faster. Since the decontamination solutions are typically slightly acidic and the point of zero charge of the manganese oxides are rather high > pH 4.5 the material had to be modified. This modified material had tolerance to acidic solutions and it's Co uptake performance remained high in the solutions of lower pH (pH 3). Increasing the ion concentration of test solutions, background concentration, didn't affect the final Co uptake level; however, some changes in the uptake kinetics could be seen. The increase in EDTA/MoMO ratio was clearly reflected in the Co uptake curves. The obtained results of manganese oxide were very promising for the treatment of EDTA complexed Co solutions. The better performance values and cheaper production cost of manganese oxide, compared to titanium dioxide, is so big driving force that further studies on the material are evident. The possibilities for continuous treatment, instead of the fluidized bed -type batch experiment are investigated and the effects of other compounds affecting the de-complexation of Co-EDTA are further studied. (authors)« less

Selective breeding of mice for different susceptibilities to high fat diet-induced glucose intolerance: Development of two novel mouse lines, Selectively bred Diet-induced Glucose intolerance-Prone and -Resistant.

PubMed

Nagao, Mototsugu; Asai, Akira; Kawahara, Momoyo; Nakajima, Yasushi; Sato, Yuki; Tanimura, Kyoko; Okajima, Fumitaka; Takaya, Makiyo; Sudo, Mariko; Takemitsu, Shuji; Harada, Taro; Sugihara, Hitoshi; Oikawa, Shinichi

2012-06-06

Aims/Introduction:  The development of type 2 diabetes is primarily due to lifestyle and environmental factors, as well as genetics, as shown by familial clustering. To establish mouse lines for evaluating heritable factors determining susceptibility to diet-induced diabetes, we performed selective breeding for differences in high fat diet (HFD)-induced glucose intolerance.   Selective breeding was performed using hybrid mice of C57BL/6J, C3H/HeJ and AKR/N backgrounds. After 5-week HFD feeding, mice showing high and low 2-h blood glucose levels in an oral glucose tolerance test (OGTT) were selected and bred over 14 generations to produce lines prone and resistant to diet-induced glucose intolerance (designated Selectively bred Diet-induced Glucose intolerance-Prone [SDG-P] and -Resistant [SDG-R]).   At 5 weeks of age (pre HFD feeding), SDG-P mice showed higher blood glucose levels both in the OGTT and insulin tolerance test as compared to SDG-R mice. After receiving HFD, the glucose intolerance of SDG-P mice became more evident without hyper insulin secretion. In addition, SDG-P mice had greater body weight gain and lower HDL-cholesterol levels as compared to SDG-R mice. In comparison with C57BL/6J, a well-known strain prone to HFD-induced glucose intolerance, SDG-P mice showed significantly higher glucose levels in OGTT after the 5-week HFD feeding.   Susceptibility to HFD-induced glucose intolerance was transmitted over generations and was intensified by selective breeding. The newly established mouse lines, SDG-P and SDG-R, may be useful in investigating the pathophysiology of type 2 diabetes through elucidating the crucial factors for determining the susceptibility to HFD-induced glucose intolerance. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2011.00175.x, 2011).

Laser-induced local activation of Mg-doped GaN with a high lateral resolution for high power vertical devices

NASA Astrophysics Data System (ADS)

Kurose, Noriko; Matsumoto, Kota; Yamada, Fumihiko; Roffi, Teuku Muhammad; Kamiya, Itaru; Iwata, Naotaka; Aoyagi, Yoshinobu

2018-01-01

A method for laser-induced local p-type activation of an as-grown Mg-doped GaN sample with a high lateral resolution is developed for realizing high power vertical devices for the first time. As-grown Mg-doped GaN is converted to p-type GaN in a confined local area. The transition from an insulating to a p-type area is realized to take place within about 1-2 μm fine resolution. The results show that the technique can be applied in fabricating the devices such as vertical field effect transistors, vertical bipolar transistors and vertical Schottkey diode so on with a current confinement region using a p-type carrier-blocking layer formed by this technique.

Evaluating plyometric exercises using time to stabilization.

PubMed

Ebben, William P; Vanderzanden, Tyler; Wurm, Bradley J; Petushek, Erich J

2010-02-01

Plyometric exercises are frequently used in strength and conditioning and rehabilitation programs because the landing phase of these exercises requires dynamic stabilization. This study examined the differences in landing stability of a variety of plyometric exercises by assessing time to stabilization (TTS), its reliability, and sex differences therein. Forty-nine men and women performed a variety of plyometric exercises thought to represent a continuum of difficulty of dynamic stabilization during landing. Plyometric exercises included line hops, cone hops, squat jumps, tuck jumps, countermovement jumps, dumbbell countermovement jumps, and single leg countermovement jumps, each performed for 3 repetitions on a force platform. A 2-way mixed analysis of covariance with repeated measures for plyometric exercise type was used to evaluate the main effects for plyometric exercise type and the interaction between plyometric exercise type and sex for TTS. Subject jumping ability was evaluated as a covariate. Results revealed significant main effects for plyometric exercise type (p < or = 0.001) and for the interaction between plyometric exercise type and sex (p = 0.002). Bonferroni adjusted post hoc analysis demonstrated differences in TTS between a number of plyometric exercises for men and women. Reliability analysis revealed intraclass correlation coefficients ranging from 0.51 to 0.86 with no significant difference between trials (p > 0.05). Practitioners who use plyometrics to train dynamic stability should create programs that progress the intensity of the exercises based on the results of this study. This study also demonstrated that TTS is moderately to highly reliable for a variety of jumping conditions for both men and women.

A molybdenum disulfide/carbon nanotube heterogeneous complementary inverter.

PubMed

Huang, Jun; Somu, Sivasubramanian; Busnaina, Ahmed

2012-08-24

We report a simple, bottom-up/top-down approach for integrating drastically different nanoscale building blocks to form a heterogeneous complementary inverter circuit based on layered molybdenum disulfide and carbon nanotube (CNT) bundles. The fabricated CNT/MoS(2) inverter is composed of n-type molybdenum disulfide (MOS(2)) and p-type CNT transistors, with a high voltage gain of 1.3. The CNT channels are fabricated using directed assembly while the layered molybdenum disulfide channels are fabricated by mechanical exfoliation. This bottom-up fabrication approach for integrating various nanoscale elements with unique characteristics provides an alternative cost-effective methodology to complementary metal-oxide-semiconductors, laying the foundation for the realization of high performance logic circuits.

Synthesis and characterization of n-type NiO:Al thin films for fabrication of p-n NiO homojunctions

NASA Astrophysics Data System (ADS)

Sun, Hui; Liao, Ming-Han; Chen, Sheng-Chi; Li, Zhi-Yue; Lin, Po-Chun; Song, Shu-Mei

2018-03-01

n-type NiO:Al thin films were deposited by RF magnetron sputtering. Their optoelectronic properties versus Al target power was investigated. The results show that with increasing Al target power, the conduction type of NiO films changes from p-type to n-type. The variation of the film’s electrical and optical properties depends on Al amount in the film. When Al target power is relatively low, Al3+ cations tend to enter nickel vacancy sites, which makes the lattice structure of NiO more complete. This improves the carrier mobility and film’s transmittance. However, when Al target power exceeds 40 W, Al atoms begin to enter into interstitial sites and form an Al cluster in the NiO film. This behavior is beneficial for improving the film’s n-type conductivity but degrades the film’s transmittance. Finally, Al/(p-type NiO)/(n-type NiO:Al)/ITO homojunctions were fabricated. Their performance was compared with Al/(p-type NiO)/ITO heterojunctions without an n-type NiO layer. Thanks to the better interface quality between the two NiO layers, the homojunctions present better performance.

Metabolic Respiration Induces AMPK- and Ire1p-Dependent Activation of the p38-Type HOG MAPK Pathway

PubMed Central

Adhikari, Hema; Cullen, Paul J.

2014-01-01

Evolutionarily conserved mitogen activated protein kinase (MAPK) pathways regulate the response to stress as well as cell differentiation. In Saccharomyces cerevisiae, growth in non-preferred carbon sources (like galactose) induces differentiation to the filamentous cell type through an extracellular-signal regulated kinase (ERK)-type MAPK pathway. The filamentous growth MAPK pathway shares components with a p38-type High Osmolarity Glycerol response (HOG) pathway, which regulates the response to changes in osmolarity. To determine the extent of functional overlap between the MAPK pathways, comparative RNA sequencing was performed, which uncovered an unexpected role for the HOG pathway in regulating the response to growth in galactose. The HOG pathway was induced during growth in galactose, which required the nutrient regulatory AMP-dependent protein kinase (AMPK) Snf1p, an intact respiratory chain, and a functional tricarboxylic acid (TCA) cycle. The unfolded protein response (UPR) kinase Ire1p was also required for HOG pathway activation in this context. Thus, the filamentous growth and HOG pathways are both active during growth in galactose. The two pathways redundantly promoted growth in galactose, but paradoxically, they also inhibited each other's activities. Such cross-modulation was critical to optimize the differentiation response. The human fungal pathogen Candida albicans showed a similar regulatory circuit. Thus, an evolutionarily conserved regulatory axis links metabolic respiration and AMPK to Ire1p, which regulates a differentiation response involving the modulated activity of ERK and p38 MAPK pathways. PMID:25356552

A Review of SnSe: Growth and Thermoelectric Properties

NASA Astrophysics Data System (ADS)

Nguyen, Van Quang; Kim, Jungdae; Cho, Sunglae

2018-04-01

SnSe is a 2D semiconductor with an indirect energy gap of 0.86 - 1 eV; it is widely used in solar cell, optoelectronics, and electronic device applications. Recently, SnSe has been considered as a robust candidate for energy conversion applications due to its high thermoelectric performance ( ZT = 2.6 in p-type and 2.2 in n-type), which is assigned mainly to its anhamornic bonding leading to an ultralow thermal conductivity. In this review, we first discuss the crystalline and electronic structures of SnSe and the source of its p-type characteristic. Then, some typical single crystal and polycrystal growth techniques, as well as an epitaxial thin film growth technique, are outlined. The reported thermoelectric properties of SnSe grown by using each technique are also reviewed. Finally, we will describe some remaining issues concerning the use of SnSe for thermoelectric applications.

Frontal plane landing mechanics in high-arched compared with low-arched female athletes.

PubMed

Powell, Douglas W; Hanson, Nicholas J; Long, Benjamin; Williams, D S Blaise

2012-09-01

To examine ground reaction forces (GRFs); frontal plane hip, knee, and ankle joint angles; and moments in high-arched (HA) and low-arched (LA) athletes during landing. Experimental study. Controlled research laboratory. Twenty healthy female recreational athletes (10 HA and 10 LA). Athletes performed 5 barefoot drop landings from a height of 30 cm. Frontal plane ankle, knee, and hip joint angles (in degrees) at initial contact, peak vertical GRF, and peak knee flexion; peak ankle, knee, and hip joint moments in the frontal plane. Vertical GRF profiles were similar between HA and LA athletes (P = 0.78). The HA athletes exhibited significantly smaller peak ankle inversion angles than the LA athletes (P = 0.01) at initial contact. At peak vertical GRF, HA athletes had significantly greater peak knee (P = 0.01) and hip abduction angles than LA athletes (P = 0.02). There were no significant differences between HA and LA athletes in peak joint moments (hip: P = 0.68; knee: P = 0.71; ankle: P = 0.15). These findings demonstrate that foot type is associated with altered landing mechanics, which may underlie lower extremity injuries. The ankle-driven strategy previously reported in female athletes suggests that foot function may have a greater relationship with lower extremity injury than that in male athletes. Future research should address the interaction of foot type and gender during landing tasks.

Association of type 1 diabetes and concentrations of drinking water components in Newfoundland and Labrador, Canada

PubMed Central

Chafe, Roger; Aslanov, Rana; Sarkar, Atanu; Gregory, Peter; Comeau, Alex; Newhook, Leigh Anne

2018-01-01

Objective To determine the association between drinking water quality and rates of type 1 diabetes in the Newfoundland and Labrador (NL) population, which has one of the highest incidences of type 1 diabetes reported globally. Research design and methods The study used a community-based, case-control design. We first calculated incidence rates of type 1 diabetes at the provincial, regional and community levels. The connection between incidence rates and components in public water supplies were then analyzed in three ways: to evaluate differences in water quality between communities with and without incident cases of type 1 diabetes, and to analyze the relationship between water quality and incidence rates of type 1 diabetes at both the community and regional levels. Results The provincial incidence of type 1 diabetes was 51.7/100 000 (0-14 year age group) for the period studied. In the community-based analysis, there were significant associations found between higher concentrations of arsenic (β=0.268, P=0.013) and fluoride (β=0.202, P=0.005) in drinking water and higher incidence of type 1 diabetes. In the regional analysis, barium (β=−0.478, P=0.009) and nickel (β=−0.354, P=0.050) concentrations were negatively associated with incidence of type 1 diabetes. Conclusions We confirmed the high incidence of type 1 diabetes in NL. We also found that concentrations of some components in drinking water were associated with higher incidence of type 1 diabetes, but no component was found to have a significant association across the three different levels of analysis performed. PMID:29527309

[Effect of high-intensity interval training on the reduction of glycosylated hemoglobin in type-2 diabetic adult patients].

PubMed

Aguilera Eguía, Raúl Alberto; Russell Guzmán, Javier Antonio; Soto Muñoz, Marcelo Enrique; Villegas González, Bastián Eduardo; Poblete Aro, Carlos Emilio; Ibacache Palma, Alejandro

2015-03-05

Type 2 diabetes mellitus is one of the major non-communicable chronic diseases in the world. Its prevalence in Chile is significant, and complications associated with this disease involve great costs, which is why prevention and treatment of this condition are essential. Physical exercise is an effective means for prevention and treatment of type 2 diabetes mellitus. The emergence of new forms of physical training, such as "high intensity interval training", presents novel therapeutic alternatives for patients and health care professionals. To assess the validity and applicability of the results regarding the effectiveness of high intensity interval training in reducing glycosylated hemoglobin in adult patients with type 2 diabetes mellitus and answer the following question: In subjects with type 2 diabetes, can the method of high intensity interval training compared to moderate intensity exercise decrease glycosylated hemoglobin? We performed a critical analysis of the article "Feasibility and preliminary effectiveness of high intensity interval training in type 2 diabetes". We found no significant differences in the amount of glycosylated hemoglobin between groups of high intensity interval training and moderate-intensity exercise upon completion of the study (p>0.05). In adult patients with type 2 diabetes mellitus, high intensity interval training does not significantly improve glycosylated hemoglobin levels. Despite this, the high intensity interval training method shows as much improvement in body composition and physical condition as the moderate intensity exercise program.

Synthesis and properties of silicon nanowire devices

NASA Astrophysics Data System (ADS)

Byon, Kumhyo

Silicon nanowire (SiNW) is a very attractive one-dimensional material for future nanoelectronic applications. Reliable control of key field effect transistor (FET) parameters such as conductance, mobility, threshold voltage and on/off ratio is crucial to the applications of SiNW to working logic devices and integrated circuits. In this thesis, we fabricated silicon nanowire field effect transistors (SiNW FETs) and studied the dependence of their electrical transport properties upon various parameters including SiNW growth conditions, post-growth doping, and contact annealing. From these studies, we found how different processes control important FET characteristics. Key accomplishments of this thesis include p-channel enhancement mode FETs, n-channel FETs by post-growth vapor doping and high performance ambipolar devices. In the first part of this work, single crystalline SiNWs were synthesized by thermal evaporation without gold catalysts. FETs were fabricated using both as-grown SiNWs and post-growth n-doped SiNWs. FET from p-type source materials behaves as a p-channel enhancement mode FET which is predominant in logic devices due to its fast operation and low power consumption. Using bismuth vapor, the as-grown SiNWs were doped into n-type materials. The majority carriers in SiNWs can therefore be controlled by proper choice of the vapor phase dopant species. Post-growth doping using vapor phase is applicable to other nanowire systems. In the second part, high performance ambipolar FETs were fabricated. A two step annealing process was used to control the Schottky barrier between SiNW and metal contacts in order to enhance device performance. Initial p-channel SiNW FETs were converted into ambipolar SiNW FETs after contact annealing. Furthermore, significant increases in both on/off ratio and channel mobilities were achieved after contact annealing. Promising device structures to implement ambipolar devices into large scale integrated circuits were proposed. The contributions of this study are to further understanding of the electrical transport properties of SiNWs and to provide optimized processes to fabricate emerging high performance nanoelectronic devices using SiNWs for future generation beyond bulk silicon.

Genome-Wide Identification, Characterization and Expression Analysis of the TCP Gene Family in Prunus mume

PubMed Central

Zhou, Yuzhen; Xu, Zongda; Zhao, Kai; Yang, Weiru; Cheng, Tangren; Wang, Jia; Zhang, Qixiang

2016-01-01

TCP proteins, belonging to a plant-specific transcription factors family, are known to have great functions in plant development, especially flower and leaf development. However, there is little information about this gene family in Prunus mume, which is widely cultivated in China as an ornamental and fruit tree. Here a genome-wide analysis of TCP genes was performed to explore their evolution in P. mume. Nineteen PmTCPs were identified and three of them contained putative miR319 target sites. Phylogenetic and comprehensive bioinformatics analyses of these genes revealed that different types of TCP genes had undergone different evolutionary processes and the genes in the same clade had similar chromosomal location, gene structure, and conserved domains. Expression analysis of these PmTCPs indicated that there were diverse expression patterns among different clades. Most TCP genes were predominantly expressed in flower, leaf, and stem, and showed high expression levels in the different stages of flower bud differentiation, especially in petal formation stage and gametophyte development. Genes in TCP-P subfamily had main roles in both flower development and gametophyte development. The CIN genes in double petal cultivars might have key roles in the formation of petal, while they were correlated with gametophyte development in the single petal cultivar. The CYC/TB1 type genes were highly detected in the formation of petal and pistil. The less-complex flower types of P. mume might result from the fact that there were only two CYC type genes present in P. mume and a lack of CYC2 genes to control the identity of flower types. These results lay the foundation for further study on the functions of TCP genes during flower development. PMID:27630648

Genome-Wide Identification, Characterization and Expression Analysis of the TCP Gene Family in Prunus mume.

PubMed

Zhou, Yuzhen; Xu, Zongda; Zhao, Kai; Yang, Weiru; Cheng, Tangren; Wang, Jia; Zhang, Qixiang

2016-01-01

TCP proteins, belonging to a plant-specific transcription factors family, are known to have great functions in plant development, especially flower and leaf development. However, there is little information about this gene family in Prunus mume, which is widely cultivated in China as an ornamental and fruit tree. Here a genome-wide analysis of TCP genes was performed to explore their evolution in P. mume. Nineteen PmTCPs were identified and three of them contained putative miR319 target sites. Phylogenetic and comprehensive bioinformatics analyses of these genes revealed that different types of TCP genes had undergone different evolutionary processes and the genes in the same clade had similar chromosomal location, gene structure, and conserved domains. Expression analysis of these PmTCPs indicated that there were diverse expression patterns among different clades. Most TCP genes were predominantly expressed in flower, leaf, and stem, and showed high expression levels in the different stages of flower bud differentiation, especially in petal formation stage and gametophyte development. Genes in TCP-P subfamily had main roles in both flower development and gametophyte development. The CIN genes in double petal cultivars might have key roles in the formation of petal, while they were correlated with gametophyte development in the single petal cultivar. The CYC/TB1 type genes were highly detected in the formation of petal and pistil. The less-complex flower types of P. mume might result from the fact that there were only two CYC type genes present in P. mume and a lack of CYC2 genes to control the identity of flower types. These results lay the foundation for further study on the functions of TCP genes during flower development.

Enabling Earth-Abundant Pyrite (FeS2) Semiconductor Nanostructures for High Performance Photovoltaic Devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jin, Song

2014-11-18

This project seeks to develop nanostructures of iron pyrite, an earth-abundant semiconductor, to enable their applications in high-performance photovoltaic (PV) devices. Growth of high purity iron pyrite nanostructures (nanowires, nanorods, and nanoplates), as well as iron pyrite thin films and single crystals, has been developed and their structures characterized. These structures have been fundamentally investigated to understand the origin of the low solar energy conversion efficiency of iron pyrite and various passivation strategies and doping approaches have been explored in order to improve it. By taking advantage of the high surface-to-bulk ratio in nanostructures and effective electrolyte gating, we fullymore » characterized both the surface inversion and bulk electrical transport properties for the first time through electrolyte-gated Hall measurements of pyrite nanoplate devices and show that pyrite is n-type in the bulk and p-type near the surface due to strong inversion, which has important consequences to using nanocrystalline pyrite for efficient solar energy conversion. Furthermore, through a comprehensive investigation on n-type iron pyrite single crystals, we found the ionization of high-density bulk deep donor states, likely resulting from bulk sulfur vacancies, creates a non-constant charge distribution and a very narrow surface space charge region that limits the total barrier height, thus satisfactorily explains the limited photovoltage and poor photoconversion efficiency of iron pyrite single crystals. These findings suggest new ideas on how to improve single crystal pyrite and nanocrystalline or polycrystalline pyrite films to enable them for high performance solar applications.« less

Near-thermal limit gating in heavily doped III-V semiconductor nanowires using polymer electrolytes

NASA Astrophysics Data System (ADS)

Ullah, A. R.; Carrad, D. J.; Krogstrup, P.; Nygârd, J.; Micolich, A. P.

2018-02-01

Doping is a common route to reducing nanowire transistor on-resistance but it has limits. A high doping level gives significant loss in gate performance and ultimately complete gate failure. We show that electrolyte gating remains effective even when the Be doping in our GaAs nanowires is so high that traditional metal-oxide gates fail. In this regime we obtain a combination of subthreshold swing and contact resistance that surpasses the best existing p -type nanowire metal-oxide semiconductor field-effect transistors (MOSFETs). Our subthreshold swing of 75 mV/dec is within 25 % of the room-temperature thermal limit and comparable with n -InP and n -GaAs nanowire MOSFETs. Our results open a new path to extending the performance and application of nanowire transistors, and motivate further work on improved solid electrolytes for nanoscale device applications.

Application of Athletic Movement Tests that Predict Injury Risk in a Military Population: Development of Normative Data.

PubMed

Teyhen, Deydre S; Shaffer, Scott W; Butler, Robert J; Goffar, Stephen L; Kiesel, Kyle B; Rhon, Daniel I; Boyles, Robert E; McMillian, Daniel J; Williamson, Jared N; Plisky, Phillip J

2016-10-01

Performance on movement tests helps to predict injury risk in a variety of physically active populations. Understanding baseline measures for normal is an important first step. Determine differences in physical performance assessments and describe normative values for these tests based on military unit type. Assessment of power, balance, mobility, motor control, and performance on the Army Physical Fitness Test were assessed in a cohort of 1,466 soldiers. Analysis of variance was performed to compare the results based on military unit type (Rangers, Combat, Combat Service, and Combat Service Support) and analysis of covariance was performed to determine the influence of age and gender. Rangers performed the best on all performance and fitness measures (p < 0.05). Combat soldiers performed better than Combat Service and Service Support soldiers on several physical performance tests and the Army Physical Fitness Test (p < 0.05). Performance in Combat Service and Service Support soldiers was equivalent on most measures (p < 0.05). Functional performance and level of fitness varied significantly by military unit type. Understanding these differences will provide a foundation for future injury prediction and prevention strategies. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

Modeling of thin, back-wall silicon solar cells

NASA Technical Reports Server (NTRS)

Baraona, C. R.

1979-01-01

The performance of silicon solar cells with p-n junctions on the nonilluminated surface (i.e., upside-down or back-wall cells) was calculated. These structures consisted of a uniformly shaped p-type substrate layer, a p(+)-type field layer on the front (illuminated) surface, and a shallow, n-type junction on the back (nonilluminated) surface. A four-layer solar cell model was used to calculate efficiency, open-circuit voltage, and short-circuit current. The effect on performance of p-layer thickness and resistivity was determined. The diffusion length was varied to simulate the effect of radiation damage. The results show that peak initial efficiencies greater than 15 percent are possible for cell thicknesses or 100 micrometers or less. After 10 years of radiation damage in geosynchronous orbit, thin (25 to 50 micrometers thick) cells made from 10 to 100 ohm cm material show the smallest decrease (approximately 10 percent) in performance.

Tunnel-injected sub 290 nm ultra-violet light emitting diodes with 2.8% external quantum efficiency

NASA Astrophysics Data System (ADS)

Zhang, Yuewei; Jamal-Eddine, Zane; Akyol, Fatih; Bajaj, Sanyam; Johnson, Jared M.; Calderon, Gabriel; Allerman, Andrew A.; Moseley, Michael W.; Armstrong, Andrew M.; Hwang, Jinwoo; Rajan, Siddharth

2018-02-01

We report on the high efficiency tunnel-injected ultraviolet light emitting diodes (UV LEDs) emitting at 287 nm. Deep UV LED performance has been limited by the severe internal light absorption in the p-type contact layers and low electrical injection efficiency due to poor p-type conduction. In this work, a polarization engineered Al0.65Ga0.35N/In0.2Ga0.8N tunnel junction layer is adopted for non-equilibrium hole injection to replace the conventionally used direct p-type contact. A reverse-graded AlGaN contact layer is further introduced to realize a low resistance contact to the top n-AlGaN layer. This led to the demonstration of a low tunnel junction resistance of 1.9 × 10-3 Ω cm2 obtained at 1 kA/cm2. Light emission at 287 nm with an on-wafer peak external quantum efficiency of 2.8% and a wall-plug efficiency of 1.1% was achieved. The measured power density at 1 kA/cm2 was 54.4 W/cm2, confirming the efficient hole injection through interband tunneling. With the benefits of the minimized internal absorption and efficient hole injection, a tunnel-injected UV LED structure could enable future high efficiency UV emitters.

Implications of electronic short circuiting in plasma sprayed solid oxide fuel cells on electrode performance evaluation by electrochemical impedance spectroscopy

NASA Astrophysics Data System (ADS)

White, B. D.; Kesler, O.

Electronic short circuiting of the electrolyte in a solid oxide fuel cell (SOFC) arising from flaws in the plasma spray fabrication process has been found to have a significant effect on the perceived performance of the electrodes, as evaluated by electrochemical impedance spectroscopy (EIS). The presence of a short circuit has been found to lead to the underestimation of the electrode polarization resistance (R p) and hence an overestimation of electrode performance. The effect is particularly noticeable when electrolyte resistance is relatively high, for example during low to intermediate temperature operation, leading to an obvious deviation from the expected Arrhenius-type temperature dependence of R p. A method is developed for determining the real electrode performance from measurements of various cell properties, and strategies for eliminating the occurrence of short circuiting in plasma sprayed cells are identified.

High-Performance Complementary Transistors and Medium-Scale Integrated Circuits Based on Carbon Nanotube Thin Films.

PubMed

Yang, Yingjun; Ding, Li; Han, Jie; Zhang, Zhiyong; Peng, Lian-Mao

2017-04-25

Solution-derived carbon nanotube (CNT) network films with high semiconducting purity are suitable materials for the wafer-scale fabrication of field-effect transistors (FETs) and integrated circuits (ICs). However, it is challenging to realize high-performance complementary metal-oxide semiconductor (CMOS) FETs with high yield and stability on such CNT network films, and this difficulty hinders the development of CNT-film-based ICs. In this work, we developed a doping-free process for the fabrication of CMOS FETs based on solution-processed CNT network films, in which the polarity of the FETs was controlled using Sc or Pd as the source/drain contacts to selectively inject carriers into the channels. The fabricated top-gated CMOS FETs showed high symmetry between the characteristics of n- and p-type devices and exhibited high-performance uniformity and excellent scalability down to a gate length of 1 μm. Many common types of CMOS ICs, including typical logic gates, sequential circuits, and arithmetic units, were constructed based on CNT films, and the fabricated ICs exhibited rail-to-rail outputs because of the high noise margin of CMOS circuits. In particular, 4-bit full adders consisting of 132 CMOS FETs were realized with 100% yield, thereby demonstrating that this CMOS technology shows the potential to advance the development of medium-scale CNT-network-film-based ICs.

Silicon homo-heterojunction solar cells: A promising candidate to realize high performance more stably

NASA Astrophysics Data System (ADS)

Tan, Miao; Zhong, Sihua; Wang, Wenjie; Shen, Wenzhong

2017-08-01

We have investigated the influences of diverse physical parameters on the performances of a silicon homo-heterojunction (H-H) solar cell, which encompasses both homojunction and heterojunction, together with their underlying mechanisms by the aid of AFORS-HET simulation. It is found that the performances of H-H solar cell are less sensitive to (i) the work function of the transparent conductive oxide layer, (ii) the interfacial density of states at the front hydrogenated amorphous silicon/crystalline silicon (a-Si:H/c-Si) interface, (iii) the peak dangling bond defect densities within the p-type a-Si:H (p-a-Si:H) layer, and (iv) the doping concentration of the p-a-Si:H layer, when compared to that of the conventional heterojunction with intrinsic thin layer (HIT) counterparts. These advantages are due to the fact that the interfacial recombination and the recombination within the a-Si:H region are less affected by all the above parameters, which fundamentally benefit from the field-effect passivation of the homojunction. Therefore, the design of H-H structure can provide an opportunity to produce high-efficiency solar cells more stably.

Correlating optical infrared and electronic properties of low tellurium doped GaSb bulk crystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roodenko, K., E-mail: kroodenko@intelliepi.com; Liao, P.-K.; Lan, D.

2016-04-07

Control over the Te doping concentration is especially challenging in the mass-production of optically transparent, high-resistivity Te-doped GaSb crystals. Driven by the necessity to perform fast, robust, and non-destructive quality control of the Te doping homogeneity of the optically transparent large-diameter GaSb wafers, we correlated electronic and optical infrared properties of Te-doped GaSb crystals. The study was based on the experimental Hall and Fourier-Transform Infrared (FTIR) data collected from over 50 samples of the low-doped n-type material (carrier concentration of 6 × 10{sup 16} cm{sup −3} to 7 × 10{sup 17} cm{sup −3}) and the Te-doped p-type GaSb (4.6 ×more » 10{sup 15} cm{sup −3} to 1 × 10{sup 16} cm{sup −3}). For the n-type GaSb, the analysis of the FTIR data was performed using free carrier absorption model, while for the p-type material, the absorption was modeled using inter-valence band absorption mechanism. Using the correlation between the Hall and the IR data, FTIR maps across the wafers allow a fast and reliable way to estimate carrier concentration profile within the wafer.« less

Analytic and clinical performance of cobas HPV testing in anal specimens from HIV-positive men who have sex with men.

PubMed

Wentzensen, Nicolas; Follansbee, Stephen; Borgonovo, Sylvia; Tokugawa, Diane; Sahasrabuddhe, Vikrant V; Chen, Jie; Lorey, Thomas S; Gage, Julia C; Fetterman, Barbara; Boyle, Sean; Sadorra, Mark; Tang, Scott Dahai; Darragh, Teresa M; Castle, Philip E

2014-08-01

Anal human papillomavirus (HPV) infections are common, and the incidence of anal cancer is high in HIV-infected men who have sex with men (MSM). To evaluate the performance of HPV assays in anal samples, we compared the cobas HPV test (cobas) to the Roche Linear Array HPV genotyping assay (LA) and cytology in HIV-infected MSM. Cytology and cobas and LA HPV testing were conducted for 342 subjects. We calculated agreement between the HPV assays and the clinical performance of HPV testing and HPV genotyping alone and in combination with anal cytology. We observed high agreement between cobas and LA, with cobas more likely than LA to show positive results for HPV16, HPV18, and other carcinogenic types. Specimens testing positive in cobas but not in LA were more likely to be positive for other markers of HPV-related disease compared to those testing negative in both assays, suggesting that at least some of these were true positives for HPV. cobas and LA showed high sensitivities but low specificities for the detection of anal intraepithelial neoplasia grade 2/3 (AIN2/3) in this population (100% sensitivity and 26% specificity for cobas versus 98.4% sensitivity and 28.9% specificity for LA). A combination of anal cytology and HPV genotyping provided the highest accuracy for detecting anal precancer. A higher HPV load was associated with a higher risk of AIN2/3 with HPV16 (P(trend) < 0.001), HPV18 (P(trend) = 0.07), and other carcinogenic types (P(trend) < 0.001). We demonstrate that cobas can be used for HPV detection in anal cytology specimens. Additional tests are necessary to identify men at the highest risk of anal cancer among those infected with high-risk HPV. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Macroscopic appearance of Type IV and giant Type III is a high risk for a poor prognosis in pathological stage II/III advanced gastric cancer with postoperative adjuvant chemotherapy

PubMed Central

Yamashita, Keishi; Ema, Akira; Hosoda, Kei; Mieno, Hiroaki; Moriya, Hiromitsu; Katada, Natsuya; Watanabe, Masahiko

2017-01-01

AIM To evaluate whether a high risk macroscopic appearance (Type IV and giant Type III) is associated with a dismal prognosis after curative surgery, because its prognostic relevance remains elusive in pathological stage II/III (pStage II/III) gastric cancer. METHODS One hundred and seventy-two advanced gastric cancer (defined as pT2 or beyond) patients with pStage II/III who underwent curative surgery plus adjuvant S1 chemotherapy were evaluated, and the prognostic relevance of a high-risk macroscopic appearance was examined. RESULTS Advanced gastric cancers with a high-risk macroscopic appearance were retrospectively identified by preoperative recorded images. A high-risk macroscopic appearance showed a significantly worse relapse free survival (RFS) (35.7%) and overall survival (OS) (34%) than an average risk appearance (P = 0.0003 and P < 0.0001, respectively). A high-risk macroscopic appearance was significantly associated with the 13th Japanese Gastric Cancer Association (JGCA) pT (P = 0.01), but not with the 13th JGCA pN. On univariate analysis for RFS and OS, prognostic factors included 13th JGCA pStage (P < 0.0001) and other clinicopathological factors including macroscopic appearance. A multivariate Cox proportional hazards model for univariate prognostic factors identified high-risk macroscopic appearance (P = 0.036, HR = 2.29 for RFS and P = 0.021, HR = 2.74 for OS) as an independent prognostic indicator. CONCLUSION A high-risk macroscopic appearance was associated with a poor prognosis, and it could be a prognostic factor independent of 13th JGCA stage in pStage II/III advanced gastric cancer. PMID:28451064

Performance analysis of junction-less double Gate n-p-n impact ionization MOS transistor (JLDG n-IMOS)

NASA Astrophysics Data System (ADS)

Chauhan, Manvendra Singh; Chauhan, R. K.

2018-04-01

This paper demonstrates a Junction-less Double Gate n-p-n Impact ionization MOS transistor (JLDG n-IMOS) on a very light doped p-type silicon body. Device structure proposed in the paper is based on charge plasma concept. There is no metallurgical junctions in the proposed device and does not need any impurity doping to create the drain and source regions. Due to doping-less nature, the fabrication process is simple for JLDG n-IMOS. The double gate engineering in proposed device leads to reduction in avalanche breakdown via impact ionization, generating large number of carriers in drain-body junction, resulting high ION current, small IOFF current and great improvement in ION/IOFF ratio. The simulation and examination of the proposed device have been performed on ATLAS device simulatorsoftware.

P-type surface effects for thickness variation of 2um and 4um of n-type layer in GaN LED

NASA Astrophysics Data System (ADS)

Halim, N. S. A. Abdul; Wahid, M. H. A.; Hambali, N. A. M. Ahmad; Rashid, S.; Ramli, M. M.; Shahimin, M. M.

2017-09-01

The internal quantum efficiency of III-Nitrides group, GaN light-emitting diode (LED) has been considerably limited due to the insufficient hole injection and this is caused by the lack of performance p-type doping and low hole mobility. The low hole mobility makes the hole less energetic, thus reduced the performance operation of GaN LED itself. The internal quantum efficiency of GaN-based LED with surface roughness (texture) can be changed by texture size, density, and thickness of GaN film or by the combined effects of surface shape and thickness of GaN film. Besides, due to lack of p-type GaN, attempts to look forward the potential of GaN LED relied on the thickness of n-type layer and surface shape of p-type GaN layer. This work investigates the characteristics of GaN LED with undoped n-GaN layer of different thickness and the surface shape of p-type layer. The LEDs performance is significantly altered by modifying the thickness and shape. Enhancement of n-GaN layer has led to the annihilation of electrical conductivity of the chip. Different surface geometry governs the emission rate extensively. Internal quantum efficiency is also predominantly affected by the geometry of n-GaN layer which subjected to the current spreading. It is recorded that the IQE droop can be minimized by varying the thickness of the active layer without amplifying the forward voltage. Optimum forward voltage (I-V), total emission rate relationship with the injected current and internal quantum efficiency (IQE) for 2,4 µm on four different surfaces of p-type layer are also reported in this paper.

An Efficient Amphiphilic-Type Triphenylamine-Based Organic Hole Transport Material for High-Performance and Ambient-Stable Dopant-Free Perovskite and Organic Solar Cells.

PubMed

Reddy, Saripally Sudhaker; Park, Ho-Yeol; Kwon, Haeun; Shin, Jongmoon; Kim, Chang-Su; Song, Myungkwan; Jin, Sung-Ho

2018-04-25

A new set of simply structured triphenylamine-based small molecules are synthesized and evaluated as dopant-free hole transporting materials (HTMs) for high-performance perovskite solar cells (PSCs) and bulk heterojunction inverted organic solar cells (BHJ IOSCs). Surprisingly, the new amphiphilic-type HTM-1 (with internal hydrophilic groups and peripheral hydrophobic alkyl tails) showed better compatibility and performance than the actual target molecule, that is, HTM-2 in PSCs and BHJ IOSCs. Importantly, the HTM-1-based dopant-free PSCs and BHJ IOSCs exhibited high power conversion efficiencies (PCEs) of 11.45 % and 8.34 %, respectively. These performances are superior and comparable to those of standard HTMs Spiro-OMeTAD (2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene) and PEDOT:PSS (poly(3,4-ethylenedioxythiophene)/polystyrene sulfonate) in PSCs and BHJ IOSCs, respectively. The enhanced device performance of the HTM-1-based PSCs is ascribed to its strong affinity towards the perovskite, properly aligned energy levels with respect to the perovskite valence band, and excellent hole transporting behavior. In addition, the well-organized energy levels of the HTMs showed excellent compatibility in BHJ IOSCs. The new amphiphilic-type HTM-based photovoltaic devices also showed long-term air stability over 700 h. These promising results offer new and unexpected prospects for engineering the interface between the photoactive material and HTMs in PSCs and BHJ IOSCs. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Direct mapping and characterization of dry etch damage-induced PN junction for long-wavelength HgCdTe infrared detector arrays.

PubMed

Li, Yantao; Hu, Weida; Ye, Zhenhua; Chen, Yiyu; Chen, Xiaoshuang; Lu, Wei

2017-04-01

Mercury cadmium telluride is the standard material to fabricate high-performance infrared focal plane array (FPA) detectors. However, etch-induced damage is a serious obstacle for realizing highly uniform and damage-free FPA detectors. In this Letter, the high signal-to-noise ratio and high spatial resolution scanning photocurrent microscopy (SPCM) is used to characterize the dry etch-induced inversion layer of vacancy-doped p-type Hg_1-xCd_xTe (x=0.22) material under different etching temperatures. It is found that the peak-to-peak magnitude of the SPCM profile decreases with a decrease in etching temperature, showing direct proof of controlling dry etch-induced type conversion. Our work paves the way toward seeking optimal etching processes in large-scale infrared FPAs.

Sugar-sweetened and artificially sweetened beverage consumption and risk of type 2 diabetes in men123

PubMed Central

de Koning, Lawrence; Malik, Vasanti S; Rimm, Eric B; Willett, Walter C

2011-01-01

Background: Sugar-sweetened beverages are risk factors for type 2 diabetes; however, the role of artificially sweetened beverages is unclear. Objective: The objective was to examine the associations of sugar- and artificially sweetened beverages with incident type 2 diabetes. Design: An analysis of healthy men (n = 40,389) from the Health Professionals Follow-Up Study, a prospective cohort study, was performed. Cumulatively averaged intakes of sugar-sweetened (sodas, fruit punches, lemonades, fruit drinks) and artificially sweetened (diet sodas, diet drinks) beverages from food-frequency questionnaires were tested for associations with type 2 diabetes by using Cox regression. Results: There were 2680 cases over 20 y of follow-up. After age adjustment, the hazard ratio (HR) for the comparison of the top with the bottom quartile of sugar-sweetened beverage intake was 1.25 (95% CI: 1.11, 1.39; P for trend < 0.01). After adjustment for confounders, including multivitamins, family history, high triglycerides at baseline, high blood pressure, diuretics, pre-enrollment weight change, dieting, total energy, and body mass index, the HR was 1.24 (95% CI: 1.09, 1.40; P for trend < 0.01). Intake of artificially sweetened beverages was significantly associated with type 2 diabetes in the age-adjusted analysis (HR: 1.91; 95% CI: 1.72, 2.11; P for trend < 0.01) but not in the multivariate-adjusted analysis (HR: 1.09; 95% CI: 0.98, 1.21; P for trend = 0.13). The replacement of one serving of sugar-sweetened beverage with 1 cup (≈237 mL) of coffee was associated with a risk reduction of 17%. Conclusion: Sugar-sweetened beverage consumption is associated with a significantly elevated risk of type 2 diabetes, whereas the association between artificially sweetened beverages and type 2 diabetes was largely explained by health status, pre-enrollment weight change, dieting, and body mass index. PMID:21430119

Self-supported Zn3P2 nanowire arrays grafted on carbon fabrics as an advanced integrated anode for flexible lithium ion batteries

NASA Astrophysics Data System (ADS)

Li, Wenwu; Gan, Lin; Guo, Kai; Ke, Linbo; Wei, Yaqing; Li, Huiqiao; Shen, Guozhen; Zhai, Tianyou

2016-04-01

We, for the first time, successfully grafted well-aligned binary lithium-reactive zinc phosphide (Zn3P2) nanowire arrays on carbon fabric cloth by a facile CVD method. When applied as a novel self-supported binder-free anode for lithium ion batteries (LIBs), the hierarchical three-dimensional (3D) integrated anode shows excellent electrochemical performances: a highly reversible initial lithium storage capacity of ca. 1200 mA h g-1 with a coulombic efficiency of up to 88%, a long lifespan of over 200 cycles without obvious decay, and a high rate capability of ca. 400 mA h g-1 capacity retention at an ultrahigh rate of 15 A g-1. More interestingly, a flexible LIB full cell is assembled based on the as-synthesized integrated anode and the commercial LiFePO4 cathode, and shows striking lithium storage performances very close to the half cells: a large reversible capacity over 1000 mA h g-1, a long cycle life of over 200 cycles without obvious decay, and an ultrahigh rate performance of ca. 300 mA h g-1 even at 20 A g-1. Considering the excellent lithium storage performances of coin-type half cells as well as flexible full cells, the as-prepared carbon cloth grafted well-aligned Zn3P2 nanowire arrays would be a promising integrated anode for flexible LIB full cell devices.We, for the first time, successfully grafted well-aligned binary lithium-reactive zinc phosphide (Zn3P2) nanowire arrays on carbon fabric cloth by a facile CVD method. When applied as a novel self-supported binder-free anode for lithium ion batteries (LIBs), the hierarchical three-dimensional (3D) integrated anode shows excellent electrochemical performances: a highly reversible initial lithium storage capacity of ca. 1200 mA h g-1 with a coulombic efficiency of up to 88%, a long lifespan of over 200 cycles without obvious decay, and a high rate capability of ca. 400 mA h g-1 capacity retention at an ultrahigh rate of 15 A g-1. More interestingly, a flexible LIB full cell is assembled based on the as-synthesized integrated anode and the commercial LiFePO4 cathode, and shows striking lithium storage performances very close to the half cells: a large reversible capacity over 1000 mA h g-1, a long cycle life of over 200 cycles without obvious decay, and an ultrahigh rate performance of ca. 300 mA h g-1 even at 20 A g-1. Considering the excellent lithium storage performances of coin-type half cells as well as flexible full cells, the as-prepared carbon cloth grafted well-aligned Zn3P2 nanowire arrays would be a promising integrated anode for flexible LIB full cell devices. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr08467a

Analyzing the spatio-temporal relationship between dengue vector larval density and land-use using factor analysis and spatial ring mapping

PubMed Central

2012-01-01

Background Dengue, a mosquito-borne febrile viral disease, is found in tropical and sub-tropical regions and is now extending its range to temperate regions. The spread of the dengue viruses mainly depends on vector population (Aedes aegypti and Aedes albopictus), which is influenced by changing climatic conditions and various land-use/land-cover types. Spatial display of the relationship between dengue vector density and land-cover types is required to describe a near-future viral outbreak scenario. This study is aimed at exploring how land-cover types are linked to the behavior of dengue-transmitting mosquitoes. Methods Surveys were conducted in 92 villages of Phitsanulok Province Thailand. The sampling was conducted on three separate occasions in the months of March, May and July. Dengue indices, i.e. container index (C.I.), house index (H.I.) and Breteau index (B.I.) were used to map habitats conducible to dengue vector growth. Spatial epidemiological analysis using Bivariate Pearson’s correlation was conducted to evaluate the level of interdependence between larval density and land-use types. Factor analysis using principal component analysis (PCA) with varimax rotation was performed to ascertain the variance among land-use types. Furthermore, spatial ring method was used as to visualize spatially referenced, multivariate and temporal data in single information graphic. Results Results of dengue indices showed that the settlements around gasoline stations/workshops, in the vicinity of marsh/swamp and rice paddy appeared to be favorable habitat for dengue vector propagation at highly significant and positive correlation (p = 0.001) in the month of May. Settlements around the institutional areas were highly significant and positively correlated (p = 0.01) with H.I. in the month of March. Moreover, dengue indices in the month of March showed a significant and positive correlation (p <= 0.05) with deciduous forest. The H.I. of people living around horticulture land were significantly and positively correlated (p = 0.05) during the month of May, and perennial vegetation showed a highly significant and positive correlation (p = 0.001) in the month of March with C.I. and significant and positive correlation (p <= 0.05) with B.I., respectively. Conclusions The study concluded that gasoline stations/workshops, rice paddy, marsh/swamp and deciduous forests played highly significant role in dengue vector growth. Thus, the spatio-temporal relationships of dengue vector larval density and land-use types may help to predict favorable dengue habitat, and thereby enables public healthcare managers to take precautionary measures to prevent impending dengue outbreak. PMID:23043443

Analyzing the spatio-temporal relationship between dengue vector larval density and land-use using factor analysis and spatial ring mapping.

PubMed

Sarfraz, Muhammad Shahzad; Tripathi, Nitin K; Tipdecho, Taravudh; Thongbu, Thawisak; Kerdthong, Pornsuk; Souris, Marc

2012-10-09

Dengue, a mosquito-borne febrile viral disease, is found in tropical and sub-tropical regions and is now extending its range to temperate regions. The spread of the dengue viruses mainly depends on vector population (Aedes aegypti and Aedes albopictus), which is influenced by changing climatic conditions and various land-use/land-cover types. Spatial display of the relationship between dengue vector density and land-cover types is required to describe a near-future viral outbreak scenario. This study is aimed at exploring how land-cover types are linked to the behavior of dengue-transmitting mosquitoes. Surveys were conducted in 92 villages of Phitsanulok Province Thailand. The sampling was conducted on three separate occasions in the months of March, May and July. Dengue indices, i.e. container index (C.I.), house index (H.I.) and Breteau index (B.I.) were used to map habitats conducible to dengue vector growth. Spatial epidemiological analysis using Bivariate Pearson's correlation was conducted to evaluate the level of interdependence between larval density and land-use types. Factor analysis using principal component analysis (PCA) with varimax rotation was performed to ascertain the variance among land-use types. Furthermore, spatial ring method was used as to visualize spatially referenced, multivariate and temporal data in single information graphic. Results of dengue indices showed that the settlements around gasoline stations/workshops, in the vicinity of marsh/swamp and rice paddy appeared to be favorable habitat for dengue vector propagation at highly significant and positive correlation (p = 0.001) in the month of May. Settlements around the institutional areas were highly significant and positively correlated (p = 0.01) with H.I. in the month of March. Moreover, dengue indices in the month of March showed a significant and positive correlation (p <= 0.05) with deciduous forest. The H.I. of people living around horticulture land were significantly and positively correlated (p = 0.05) during the month of May, and perennial vegetation showed a highly significant and positive correlation (p = 0.001) in the month of March with C.I. and significant and positive correlation (p <= 0.05) with B.I., respectively. The study concluded that gasoline stations/workshops, rice paddy, marsh/swamp and deciduous forests played highly significant role in dengue vector growth. Thus, the spatio-temporal relationships of dengue vector larval density and land-use types may help to predict favorable dengue habitat, and thereby enables public healthcare managers to take precautionary measures to prevent impending dengue outbreak.

Accuracy of 3D white light scanning of abutment teeth impressions: evaluation of trueness and precision.

PubMed

Jeon, Jin-Hun; Kim, Hae-Young; Kim, Ji-Hwan; Kim, Woong-Chul

2014-12-01

This study aimed to evaluate the accuracy of digitizing dental impressions of abutment teeth using a white light scanner and to compare the findings among teeth types. To assess precision, impressions of the canine, premolar, and molar prepared to receive all-ceramic crowns were repeatedly scanned to obtain five sets of 3-D data (STL files). Point clouds were compared and error sizes were measured (n=10 per type). Next, to evaluate trueness, impressions of teeth were rotated by 10°-20° and scanned. The obtained data were compared with the first set of data for precision assessment, and the error sizes were measured (n=5 per type). The Kruskal-Wallis test was performed to evaluate precision and trueness among three teeth types, and post-hoc comparisons were performed using the Mann-Whitney U test with Bonferroni correction (α=.05). Precision discrepancies for the canine, premolar, and molar were 3.7 µm, 3.2 µm, and 7.3 µm, respectively, indicating the poorest precision for the molar (P<.001). Trueness discrepancies for teeth types were 6.2 µm, 11.2 µm, and 21.8 µm, respectively, indicating the poorest trueness for the molar (P=.007). In respect to accuracy the molar showed the largest discrepancies compared with the canine and premolar. Digitizing of dental impressions of abutment teeth using a white light scanner was assessed to be a highly accurate method and provided discrepancy values in a clinically acceptable range. Further study is needed to improve digitizing performance of white light scanning in axial wall.

Novel electrochemical nickel metallization in silicon impedance engineering for mixed-signal system-on-chip crosstalk isolation

NASA Astrophysics Data System (ADS)

Zhang, Xi

One of the major challenges for single chip radio frequency integrated circuits (RFIC's) built on Si is the RE crosstalk through the Si substrate. Noise from switching transient in digital circuits can be transmitted through Si substrate and degrades the performance of analog circuit elements. A highly conductive moat or Faraday cage type structure of through-the-wafer thickness in the Si substrate was demonstrated to be effective in shielding electromagnetic interference thereby reducing RE cross-talk in high performance mixed signal integrated circuits. Such a structure incorporated into the p- Si substrate was realized by electroless Ni metallization over selected regions with ultra-high-aspect-ratio macropores that was etched electrochemically in p- Si substrates. The metallization process was conducted by immersing the macroporous Si sample in an alkaline aqueous solution containing Ni2+ without a reducing agent. It was found that working at slightly elevated temperature, Ni 2+ was rapidly reduced and deposited in the macropores. During the wet chemical process, conformal metallization on the pore wall was achieved. The entire porous Si skeleton was gradually replaced by Ni along the extended duration of immersion. In a p-/p+ epi Si substrate used for high performance digital CMOS, the suppression of crosstalk by the arrayed metallic Ni via structure fabricated from the front p side was significant that the crosstalk went down to the noise floor of the conventional measurement instruments. The process and mechanism of forming such a Ni structure over the original Si were studied. Theoretical computation relevant to the process was carried out to show a good consistency with the experiments.

Enhancing Thermoelectric Performance of PbSe by Se Vacancies

NASA Astrophysics Data System (ADS)

Liu, Yefeng; You, Li; Wang, Chenyang; Zhang, Jiye; Yang, Jiong; Guo, Kai; Luo, Jun; Zhang, Wenqing

2018-02-01

Self-doped n-type PbSe1-δ thermoelectric compounds have been successfully synthesized by the melting and annealing method. The Se vacancies are created by intentionally produced deficiency of Se elements during the sample preparation. Such intrinsic doping can raise the electron concentration to a value as high as 1.2 × 1019 cm-3, leading to greatly improved electrical conductivity and power factor in the n-type PbSe1-δ . Furthermore, the presence of Se vacancies effectively enhances the phonon scattering, resulting in reduced lattice thermal conductivity. Thus, the thermoelectric performance of n-type PbSe1-δ is significantly improved by the formation of intrinsic Se vacancies. The achieved ZT value for the Se-vacancy-rich sample varies from ˜ 0.4 at 330 K to ˜ 1.0 at 675 K, which is comparable to those of the reported n-type PbSe materials with extrinsic doping. In addition, the average ZT of our n-type PbSe system reaches 0.77, which approaches the value of p-type PbTe.

Roles of Cu in the Enhanced Thermoelectric Properties in Bi0.5Sb1.5Te₃.

PubMed

Hao, Feng; Qiu, Pengfei; Song, Qingfeng; Chen, Hongyi; Lu, Ping; Ren, Dudi; Shi, Xun; Chen, Lidong

2017-03-01

Recently, Cu-containing p-type Bi 0.5 Sb 1.5 Te₃ materials have shown high thermoelectric performances and promising prospects for practical application in low-grade waste heat recovery. However, the position of Cu in Bi 0.5 Sb 1.5 Te₃ is controversial, and the roles of Cu in the enhancement of thermoelectric performance are still not clear. In this study, via defects analysis and stability test, the possibility of Cu intercalation in p-type Bi 0.5 Sb 1.5 Te₃ materials has been excluded, and the position of Cu is identified as doping at the Sb sites. Additionally, the effects of Cu dopants on the electrical and thermal transport properties have been systematically investigated. Besides introducing additional holes, Cu dopants can also significantly enhance the carrier mobility by decreasing the Debye screen length and weakening the interaction between carriers and phonons. Meanwhile, the Cu dopants interrupt the periodicity of lattice vibration and bring stronger anharmonicity, leading to extremely low lattice thermal conductivity. Combining the suppression on the intrinsic excitation, a high thermoelectric performance-with a maximum thermoelectric figure of merit of around 1.4 at 430 K-has been achieved in Cu 0.005 Bi 0.5 Sb 1.495 Te₃, which is 70% higher than the Bi 0.5 Sb 1.5 Te₃ matrix.

Utilization of apical vaginal support procedures at time of inpatient hysterectomy performed for benign conditions: a national estimate.

PubMed

Ross, Whitney Trotter; Meister, Melanie R; Shepherd, Jonathan P; Olsen, Margaret A; Lowder, Jerry L

2017-10-01

Apical vaginal support is considered the keystone of pelvic organ support. Level I evidence supports reestablishment of apical support at time of hysterectomy, regardless of whether the hysterectomy is performed for prolapse. National rates of apical support procedure performance at time of inpatient hysterectomy have not been well described. We sought to estimate trends and factors associated with use of apical support procedures at time of inpatient hysterectomy for benign indications in a large national database. The National (Nationwide) Inpatient Sample was used to identify hysterectomies performed from 2004 through 2013 for benign indications. International Classification of Diseases, Ninth Revision, Clinical Modification codes were used to select both procedures and diagnoses. The primary outcome was performance of an apical support procedure at time of hysterectomy. Descriptive and multivariable analyses were performed. There were 3,509,230 inpatient hysterectomies performed for benign disease from 2004 through 2013. In both nonprolapse and prolapse groups, there was a significant decrease in total number of annual hysterectomies performed over the study period (P < .0001). There were 2,790,652 (79.5%) hysterectomies performed without a diagnosis of prolapse, and an apical support procedure was performed in only 85,879 (3.1%). There was a significant decrease in the proportion of hysterectomies with concurrent apical support procedure (high of 4.0% in 2004 to 2.5% in 2013, P < .0001). In the multivariable logistic regression model, increasing age, hospital type (urban teaching), hospital bed size (large and medium), and hysterectomy type (vaginal and laparoscopically assisted vaginal) were associated with performance of an apical support procedure. During the study period, 718,578 (20.5%) inpatient hysterectomies were performed for prolapse diagnoses and 266,743 (37.1%) included an apical support procedure. There was a significant increase in the proportion of hysterectomies with concurrent apical support procedure (low of 31.3% in 2005 to 49.3% in 2013, P < .0001). In the multivariable logistic regression model, increasing age, hospital type (urban teaching), hospital bed size (medium and large), and hysterectomy type (total laparoscopic and laparoscopic supracervical) were associated with performance of an apical support procedure. This national database study demonstrates that apical support procedures are not routinely performed at time of inpatient hysterectomy regardless of presence of prolapse diagnosis. Educational efforts are needed to increase awareness of the importance of reestablishing apical vaginal support at time of hysterectomy regardless of indication. Copyright © 2017 Elsevier Inc. All rights reserved.

Impact of the dynamic and static component of the sport practised for electrocardiogram analysis in screening athletes.

PubMed

Maillot, N; Guenancia, C; Yameogo, N V; Gudjoncik, A; Garnier, F; Lorgis, L; Chagué, F; Cottin, Y

2018-02-01

To interpret the electrocardiogram (ECG) of athletes, the recommendations of the ESC and the Seattle criteria define type 1 peculiarities, those induced by training, and type 2, those not induced by training, to rule out cardiomyopathy. The specificity of the screening was improved by Sheikh who defined "Refined Criteria," which includes a group of intermediate peculiarities. The aim of our study was to investigate the influence of static and dynamic components on the prevalence of different types of abnormalities. The ECGs of 1030 athletes performed during preparticipation screening were interpreted using these three classifications. Our work revealed 62/16%, 69/13%, and 71/7% of type 1 peculiarities and type 2 abnormalities for the ESC, Seattle, and Refined Criteria algorithms, respectively(P<.001). For type 2 abnormalities, three independent factors were found for the ESC and Seattle criteria: age, Afro-Caribbean origin, and the dynamic component with, for the latter, an OR[95% CI] of 2.35[1.28-4.33] (P=.006) and 1.90[1.03-3.51] (P=.041), respectively. In contrast, only the Afro-Caribbean origin was associated with type 2 abnormalities using the Refined Criteria: OR[95% CI] 2.67[1.60-4.46] (P<.0001). The Refined Criteria classified more athletes in the type 1 category and fewer in the type 2 category compared with the ESC and Seattle algorithms. Contrary to previous studies, a high dynamic component was not associated with type 2 abnormalities when the Refined Criteria were used; only the Afro-Caribbean origin remained associated. Further research is necessary to better understand adaptations with regard to duration and thus improve the modern criteria for ECG screening in athletes. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Downhill Running Excessive Training Inhibits Hypertrophy in Mice Skeletal Muscles with Different Fiber Type Composition.

PubMed

da Rocha, Alisson L; Pereira, Bruno C; Pauli, José R; de Souza, Claudio T; Teixeira, Giovana R; Lira, Fábio S; Cintra, Dennys E; Ropelle, Eduardo R; Júnior, Carlos R B; da Silva, Adelino S R

2016-05-01

The aim of this study was to verify the effects of running overtraining protocols performed in downhill, uphill, and without inclination on the proteins related to hypertrophy signaling pathway in extensor digitorum longus (EDL) and soleus of C57BL/6 mice. We also performed histological and stereological analyses. Rodents were divided into control (CT; sedentary mice), overtrained by downhill running (OTR/down), overtrained by uphill running (OTR/up), and overtrained by running without inclination (OTR). The incremental load, exhaustive, and grip force tests were used as performance evaluation parameters. 36 h after the grip force test, EDL and soleus were removed and immediately used for immunoblotting analysis or stored at -80°C for histological and stereological analyses. For EDL, OTR/down decreased the protein kinase B (Akt) and tuberous sclerosis protein 2 (TSC2) phosphorylation (p), and increased myostatin, receptor-activated Smads (pSMAD2-3), and insulin receptor substrate-1 (pIRS-1; Ser307/636). OTR/down also presented low and high relative proportions of cytoplasm and connective tissue, respectively. OTR/up increased the mammalian target of rapamycin (pmTOR), 70-kDa ribosomal protein S6 kinase 1 (pS6K1) and pSMAD2-3, and decreased pTSC2. OTR decreased pTSC2 and increased pIRS-1 (Ser636). For soleus, OTR/down increased S6 ribosomal protein (pS6RP) and pSMAD2-3, and decreased pIRS-1 (Ser639). OTR/up decreased pS6K1, pS6RP and pIRS-1 (Ser639), and increased pTSC2 (Ser939), and pSMAD2-3. OTR increased pS6RP, 4E-binding protein-1 (p4E-BP1), pTSC2 (Ser939), and pSMAD2-3, and decreased pIRS-1 (Ser639). In summary, OTR/down inhibited the skeletal muscle hypertrophy with concomitant signs of atrophy in EDL. The effects of OTR/up and OTR depended on the analyzed skeletal muscle type. © 2015 Wiley Periodicals, Inc.

Fabrication and characterization of GaN-based light-emitting diodes without pre-activation of p-type GaN.

PubMed

Hu, Xiao-Long; Wang, Hong; Zhang, Xi-Chun

2015-01-01

We fabricated GaN-based light-emitting diodes (LEDs) without pre-activation of p-type GaN. During the fabrication process, a 100-nm-thick indium tin oxide film was served as the p-type contact layer and annealed at 500°C in N2 ambient for 20 min to increase its transparency as well as to activate the p-type GaN. The electrical measurements showed that the LEDs were featured by a lower forward voltage and higher wall-plug efficiency in comparison with LEDs using pre-activation of p-type GaN. We discussed the mechanism of activation of p-type GaN at 500°C in N2 ambient. Furthermore, x-ray photoemission spectroscopy examinations were carried out to study the improved electrical performances of the LEDs without pre-activation of p-type GaN.

The Impact of Surgeon Volume on Perioperative Outcomes in Hysterectomy

PubMed Central

Vree, Florentien E. M.; Cohen, Sarah L.; Chavan, Niraj

2014-01-01

Background and Objectives: To estimate the effect of surgeon volume on key perioperative outcomes after all modes of hysterectomy. Methods: We performed a review of 1914 hysterectomies performed at a large, academic tertiary-care hospital. Women who underwent abdominal, laparoscopic, vaginal, or robotic hysterectomy for benign non-obstetric indications in 2006, 2009, and 2010 were included. Results: Gynecologic surgeons were categorized according their average annual hysterectomy case volume: low volume (<11 cases per year), intermediate volume (11–50 cases per year), and high-volume (>51 cases per year). Taking all modes of hysterectomy together, surgeries performed by high-volume surgeons required a shorter operative time (155.11 minutes vs 199.19–203.35 minutes, P < .001) and resulted in less estimated blood loss compared with low- and intermediate-volume surgeons (161.09 mL vs 205.58–237.96 mL, P < .001). The 3 surgical volume groups did not differ from each other significantly in the conversion to laparotomy, readmission rate, or incidence of intraoperative or postoperative complications. These findings were maintained when subgroup analyses were performed by type of hysterectomy, with few exceptions. In the subgroup of vaginal hysterectomies by intermediate-volume surgeons, there were slightly more postoperative complications. There were fewer intraoperative complications in laparoscopic/robotic hysterectomies performed by high-volume surgeons, though not statistically significant. Conclusions: Hysterectomies performed by high-volume surgeons at our institution during the 3-year study period were associated with shorter operative times and less estimated blood loss. PMID:24960479

A comparison of recording modalities of P300 event-related potentials (ERP) for brain-computer interface (BCI) paradigm.

PubMed

Mayaud, L; Congedo, M; Van Laghenhove, A; Orlikowski, D; Figère, M; Azabou, E; Cheliout-Heraut, F

2013-10-01

A brain-computer interface aims at restoring communication and control in severely disabled people by identification and classification of EEG features such as event-related potentials (ERPs). The aim of this study is to compare different modalities of EEG recording for extraction of ERPs. The first comparison evaluates the performance of six disc electrodes with that of the EMOTIV headset, while the second evaluates three different electrode types (disc, needle, and large squared electrode). Ten healthy volunteers gave informed consent and were randomized to try the traditional EEG system (six disc electrodes with gel and skin preparation) or the EMOTIV Headset first. Together with the six disc electrodes, a needle and a square electrode of larger surface were simultaneously recording near lead Cz. Each modality was evaluated over three sessions of auditory P300 separated by one hour. No statically significant effect was found for the electrode type, nor was the interaction between electrode type and session number. There was no statistically significant difference of performance between the EMOTIV and the six traditional EEG disc electrodes, although there was a trend showing worse performance of the EMOTIV headset. However, the modality-session interaction was highly significant (P<0.001) showing that, while the performance of the six disc electrodes stay constant over sessions, the performance of the EMOTIV headset drops dramatically between 2 and 3h of use. Finally, the evaluation of comfort by participants revealed an increasing discomfort with the EMOTIV headset starting with the second hour of use. Our study does not recommend the use of one modality over another based on performance but suggests the choice should be made on more practical considerations such as the expected length of use, the availability of skilled labor for system setup and above all, the patient comfort. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Clinical application of antenatal genetic diagnosis of osteogenesis imperfecta type IV.

PubMed

Yuan, Jing; Li, Song; Xu, YeYe; Cong, Lin

2015-04-02

Clinical analysis and genetic testing of a family with osteogenesis imperfecta type IV were conducted, aiming to discuss antenatal genetic diagnosis of osteogenesis imperfecta type IV. Preliminary genotyping was performed based on clinical characteristics of the family members and then high-throughput sequencing was applied to rapidly and accurately detect the changes in candidate genes. Genetic testing of the III5 fetus and other family members revealed missense mutation in c.2746G>A, pGly916Arg in COL1A2 gene coding region and missense and synonymous mutation in COL1A1 gene coding region. Application of antenatal genetic diagnosis provides fast and accurate genetic counseling and eugenics suggestions for patients with osteogenesis imperfecta type IV and their families.

Multi-walled carbon nanotubes as solid-phase extraction sorbents for simultaneous determination of type A trichothecenes in maize, wheat and rice by ultra-high performance liquid chromatography-tandem mass spectrometry.

PubMed

Dong, Maofeng; Si, Wenshuai; Jiang, Keqiu; Nie, Dongxia; Wu, Yongjiang; Zhao, Zhihui; De Saeger, Sarah; Han, Zheng

2015-12-04

A solid-phase extraction (SPE) procedure using multi-walled carbon nanotubes (MWCNTs) as sorbents coupled with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed for simultaneous determination of four type A trichothecenes in maize, wheat and rice for the first time. Several key parameters including the composition of sample loading solutions, washing and elution solvents were thoroughly investigated to achieve optimal SPE recoveries and efficiency. Performance of the MWCNTs materials was significantly affected by pH, and after optimization, n-hexane and 5% methanol aqueous solution as the washing solutions and methanol containing 1% formic acid as the elution solvent presented an excellent purification efficiency for the four targets in the different matrices. The method was validated by determining the linearity (R(2)≥0.992), recovery (73.4-113.7%), precision (1.2-17.1%) and sensitivity (limit of quantification in the range of 0.02-0.10μg/kg), and was further applied for simultaneous determination of type A trichothecenes in 30 samples. Although low contamination levels of type A trichothecenes in wheat, maize and rice were observed revealing mitigated risks to consumers in Shanghai, China, the developed method has proven to be a valuable tool for type A trichothecenes monitoring in complex crop matrices. Copyright © 2015 Elsevier B.V. All rights reserved.

The effect of transient loading on the performance of a mesophilic anaerobic contact reactor at constant feed strength.

PubMed

Sentürk, Elif; Ince, Mahir; Engin, Guleda Onkal

2012-12-15

Anaerobic contact reactor is a high rate anaerobic process consisting of an agitated reactor and a solids settling tank for recycling. It was proved earlier that this type of reactor design offers highly efficient performance in the conversion of organic matter to biogas. In this study, the effect of transient loading on reactor performance in terms of a number of key intermediates and parameters such as, COD removal, pH and alkalinity change, VFAs, effluent MLSS concentration and biogas efficiency over time was examined. For this purpose, a step increase of organic loading rate from 3.35kg COD/m(3)day to 15.61kg COD/m(3)day was employed. The hydraulic retention time decreased to a value of 8.42h by an increase in the influent flow-rate during the transient loading. It was observed that the mesophilic anaerobic contact reactor (MACR) was quite resistant to large transient shocks. The reactor recovered back to its baseline performance only in 15h after the shock loading was stopped. Hence, it can be concluded that this type of reactor design has a high potential in treating food processing wastewaters with varying flow characteristics. Copyright © 2012 Elsevier B.V. All rights reserved.

Hospitals with greater diversities of physiologically complex procedures do not achieve greater surgical growth in a market with stable numbers of such procedures.

PubMed

Dexter, Franklin; Epstein, Richard H; Lubarsky, David A

2018-05-01

Although having a large diversity of types of procedures has a substantial operational impact on the surgical suites of hospitals, the strategic importance is unknown. In the current study, we used longitudinal data for all hospitals and patient ages in the State of Florida to evaluate whether hospitals with greater diversity of types of physiologically complex major therapeutic procedures (PCMTP) also had greater rates of surgical growth. Observational cohort study. 1479 combinations of hospitals in the State of Florida and fiscal years, 2008-2015. The types of International Classification of Diseases, Ninth revision, Clinical Modification (ICD-9-CM) procedures studied were PCMT, defined as: a) major therapeutic procedure; b) >7 American Society of Anesthesiologists base units; and c) performed during a hospitalization with a Diagnosis Related Group with a mean length of stay ≥4.0days. The number of procedures of each type of PCMTP commonly performed at each hospital was calculated by taking 1/Herfindahl index (i.e., sum of the squares of the proportions of all procedures of each type of PCMTP). Over the 8 successive years studied, there was no change in the number of PCMTP being performed (Kendall's τ b =-0.014±0.017 [standard error], P=0.44; N=1479 hospital×years). Busier and larger hospitals commonly performed more types of PCMTP, respectively categorized based on performed PCMTP (τ=0.606±0.017, P<0.0001) or hospital beds (τ=0.524±0.017, P<0.0001). There was no association between greater diversity of types of PCMTP commonly performed and greater annual growth in numbers of PCMTP (τ=0.002±0.019, P=0.91; N=1295 hospital×years). Conclusions were the same with multiple sensitivity analyses. Post hoc, it was recognized that hospitals performing a greater diversity of PCMTP were more similar to the aggregate of other hospitals within the same health district (τ=0.550±0.017, P<0.0001). During a period with no overall growth in PCMTP, hospitals with greater diversities of types of PCMTP had growth that was, at most, minimally larger than that of the smaller hospitals, and vice-versa. Diversity is important operationally. From the perspective of delivering surgical care within a market, the unique contributions of each large teaching hospital performing many different types of PCMTP needs to be considered relative to the combined capabilities of other hospitals in its region. Copyright © 2018 Elsevier Inc. All rights reserved.

Obstructive sleep apnea and diabetes mellitus.

PubMed

Vale, Jorge; Manuel, Paula; Oliveira, Eurico; Oliveira, Ana Rita; Silva, Eloisa; Melo, Vitor; Sousa, Marta; Alexandre, João Carlos; Gil, Isabel; Sanchez, Amparo; Nascimento, Edite; Torres, António Simões

2015-01-01

There is convincing evidence that obstructive sleep apnea (OSA) is highly associated with impaired glucose metabolism. Analyze the prevalence of OSA in type 1 and type 2 diabetes mellitus (DM) patients. Evaluate the influence of OSA on glycemic control. The adult patients with diabetes mellitus (DM) followed in the department of internal medicine were referred to our Sleep Unit. A home respiratory polygraphy was then performed on all patients with body mass index (BMI) <40 kg/m(2). The glycemic control was assessed by the value of glycated hemoglobin (Hba1c) in the previous 3 months. A total of 46 patients were studied (20 men and 26 women), the mean age was 50±15 years and mean BMI was 28.6±4.9 kg/m(2). The mean Hba1c was 8.3±1.2. Twenty three patients had type 2 DM and 23 patients had type 1 DM. Twenty nine patients (63.0%) had OSA and 8.7% had severe OSA (AHI>30/h). The mean CT90 was 5.3±12.5 and the mean AHI was 13.6±18.3. The mean AHI was similar between type 1 and type 2 DM (15.7±24.5 Vs 11.6±8.9; p=0.46). The AHI was not correlated with the BMI. Type 2 DM patients with poor glycemic control (HbA1c>7.5%) had a significantly higher mean AHI (14.3±9.0 vs 6.4±6.2; p=0.038). This difference did not remain significant after adjustment for BMI (p=0.151). The prevalence of OSA in type 1 DM is similar to that found in type 2 DM. We note the high prevalence of OSA in younger patients with type 1 DM. Copyright © 2013 Sociedade Portuguesa de Pneumologia. Published by Elsevier España, S.L.U. All rights reserved.

Solution processed metal oxide thin film hole transport layers for high performance organic solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steirer, K. Xerxes; Berry, Joseph J.; Chesin, Jordan P.

2017-01-10

A method for the application of solution processed metal oxide hole transport layers in organic photovoltaic devices and related organic electronics devices is disclosed. The metal oxide may be derived from a metal-organic precursor enabling solution processing of an amorphous, p-type metal oxide. An organic photovoltaic device having solution processed, metal oxide, thin-film hole transport layer.

Engineering few-layer MoTe2 devices by Co/hBN tunnel contacts

NASA Astrophysics Data System (ADS)

Zhu, Mengjian; Luo, Wei; Wu, Nannan; Zhang, Xue-ao; Qin, Shiqiao

2018-04-01

2H phase Molybdenum ditelluride (MoTe2) is a layered two-dimensional (2D) semiconductor that has recently gained extensive attention for its intriguing properties, demonstrating great potential for nanoelectronics and optoelectronics. Optimizing the electric contacts to MoTe2 is a critical step for realizing high performance devices. Here, we demonstrate Co/hBN tunnel contacts to few-layer MoTe2. In sharp contrast to the p-type conduction of Co contacted MoTe2, Co/hBN tunnel contacted MoTe2 devices show clear n-type transport properties. Our first principles calculation reveals that the inserted few-layer hBN strongly interacts with Co and significantly reduces its work-function by ˜1.2 eV, while MoTe2 itself has a much weaker influence on the work-function of Co. This allows us to build MoTe2 diodes using the mixed Co/hBN and Co contact architecture, which can be switched from p-n type to n-p type by changing the gate-voltage, paving the way for engineering multi-functional devices based on atomically thin 2D semiconductors.

Vascular endothelial growth factor during hypoglycemia in patients with type 1 diabetes mellitus: relation to cognitive function and renin-angiotensin system activity.

PubMed

Kristensen, Peter Lommer; Høi-Hansen, Thomas; Boomsma, Frans; Pedersen-Bjergaard, Ulrik; Thorsteinsson, Birger

2009-10-01

In healthy adults, levels of vascular endothelial growth factor (VEGF) increase in response to mild hypoglycemia. VEGF is implicated in glucose transport over the blood-brain barrier, and the increase during hypoglycemia has been positively correlated with preservation of cognitive function during hypoglycemia. High activity in the renin-angiotensin system (RAS) is associated with an increased risk of severe hypoglycemia in patients with type 1 diabetes mellitus. Renin-angiotensin system possibly exerts its mechanism in hypoglycemia via VEGF. We studied the impact of mild hypoglycemia on plasma VEGF in patients with type 1 diabetes mellitus and high or low RAS activity and analyzed associations between VEGF levels and cognitive function during hypoglycemia. Eighteen patients with type 1 diabetes mellitus-9 with high and 9 with low RAS activity-underwent a single-blinded, placebo-controlled, crossover study with either mild hypoglycemia or stable glycemia. Cognitive function was assessed by the California Cognitive Assessment Package and the Alzheimer Quick Test. Nadir plasma glucose was 2.2 (0.3) mmol/L. During the control study, plasma VEGF did not change. During hypoglycemia, plasma VEGF increased from 39 to 58 pg/L in the high-RAS group (P = .004) and from 76 to 109 pg/L in the low-RAS group (P = .01), with no difference between RAS groups (P = .9). A weak association between reduced preservation of cognitive function during hypoglycemia and low VEGF response was observed. Plasma VEGF levels increase during mild, short-term hypoglycemia in patients with type 1 diabetes mellitus. The VEGF response is not dependent on RAS activity and only weakly associated with preservation of cognitive function during hypoglycemia. Thus, the previously described association between low RAS activity and better cognitive performance during hypoglycemia does not seem to be mediated by VEGF.

Effects of metformin and sitagliptin on glycolipid metabolism in type 2 diabetic rats on different diets

PubMed Central

Yang, Juhong; Ba, Tu; Chen, Liming; Shan, Chunyan; Zheng, Miaoyan; Wang, Ying; Ren, Huizhu; Chen, Jingli; Xu, Jie; Han, Fei; Zhang, Yi; Yang, Xiaoyun

2016-01-01

Introduction The aim of the study was to investigate the effects of metformin and sitagliptin on glycolipid metabolism in type 2 diabetes after different diets. Material and methods Seventy Male Sprague Dawley rats were fed with a high fat diet followed by streptozotocin treatment to induce type 2 diabetes. Then all rats were randomly divided into a control group, a metformin group (200 mg/kg), and a sitagliptin group (10 mg/kg). Each group was further divided into 4 groups receiving one load of high carbohydrate diet (45% glucose, 4.5 ml/kg), high fat diet (20% lipid emulsion, 4.5 ml/kg), high protein diet (20% whey protein, 10 ml/kg) or mixed meal, respectively. The caloric densities were all 33 kJ/kg. Postprandial blood glucose (P2BG), triglyceride (TG), glucagon-like peptide-1 (GLP-1), glucagon and insulin levels were measured. Results In the high carbohydrate group, sitagliptin was more efficient in lowering P2BG compared with metformin (p < 0.05). In the high-fat group, metformin was more powerful in lowering TG (p < 0.05) and P2BG (p < 0.05) levels because of its improvement of insulin sensitivity. In the high protein diet group, metformin did not reduce the P2BG level (p > 0.05), although it did reduce the TG level (p < 0.05). In the mixed diet group, metformin was more efficient in lowering P2BG (p < 0.05) but had a similar effect on TG (p > 0.05) compared with sitagliptin. Conclusions In the type 2 diabetic model, metformin and sitagliptin have different effects on glycolipid metabolism after different diets. If it is proved in type 2 diabetic patients, then different medicines may be recommended according to different diets in order to improve glycolipid metabolism. PMID:27186166

The Effect of Needle Type, Duration of Surgery and Position of the Patient on the Risk of Transient Neurologic Symptoms

PubMed Central

Etezadi, Farhad; Karimi Yarandi, Kourosh; Ahangary, Aylar; Shokri, Hajar; Imani, Farsad; Safari, Saeid; Khajavi, Mohammad Reza

2013-01-01

Background The incidence of transient neurologic symptoms (TNS) after spinal anesthesia with lidocaine is reported as high as 40%. Objectives This prospective clinical trial was designed to determine the incidence of TNS in patients who underwent spinal anesthesia with two different needles, in two different surgical positions. Patients and Methods The present randomized clinical trial was conducted on 250 patients (ASA I-II), who were candidates for surgery in supine or lithotomy positions. According to the needle type (Sprotte or Quincke) and local anesthetics (lidocaine and bupivacaine) all patients were randomly divided into four groups. After performing spinal anesthesia in sitting position, the position was changed into supine or lithotomy, according to surgical procedure. The patients were observed for complications of spinal anesthesia during the first five post-operative days. The primary end-point for this trial was to recognize the incidence of TNS among the four groups. Our secondary objective was to evaluate the effect of patient's position, needle type, and duration of surgery on the development of TNS following spinal anesthesia. Results TNS was most commonly observed when lidocaine was used as anesthetic drug (P = 0.003). The impact of needle type, was not significant (P = 0.7). According to multivariate analysis, the duration of surgery was significantly lower in cases suffering from TNS (P = 0.04). Also, the risk of TNS increased following surgeries performed in lithotomy position (P = 0.00). Conclusions According to the results of this clinical study, spinal anesthesia with lidocaine, and the lithotomy position in surgery increased the risk of TNS. PMID:24223352

Total Arch versus Hemiarch Replacement for Type A Acute Aortic Dissection: A Single-Center Experience.

PubMed

Lio, Antonio; Nicolò, Francesca; Bovio, Emanuele; Serrao, Andrea; Zeitani, Jacob; Scafuri, Antonio; Chiariello, Luigi; Ruvolo, Giovanni

2016-12-01

We retrospectively evaluated early and intermediate outcomes of aortic arch surgery in patients with type A acute aortic dissection (AAD), investigating the effect of arch surgery extension on postoperative results. From January 2006 through July 2013, 201 patients with type A AAD underwent urgent corrective surgery at our institution. Of the 92 patients chosen for this study, 59 underwent hemiarch replacement (hemiarch group), and 33 underwent total arch replacement (total arch group) in conjunction with ascending aorta replacement. The operative mortality rate was 22%. Total arch replacement was associated with a 33% risk of operative death, versus 15% for hemiarch ( P =0.044). Multivariable analysis found these independent predictors of operative death: age (odds ratio [OR]=1.13/yr; 95% confidence interval [CI], 1.04-1.23; P =0.002), body mass index >30 kg/m 2 (OR=9.9; 95% CI, 1.28-19; P =0.028), postoperative low cardiac output (OR=10.6; 95% CI, 1.18-25; P =0.035), and total arch replacement (OR=8.8; 95% CI, 1.39-15; P =0.021) The mean overall 5-year survival rate was 59.3% ± 5.5%, and mean 5-year freedom from distal reintervention was 95.4% ± 3.2% ( P =NS). In type A AAD, aortic arch surgery is still associated with high operative mortality rates; hemiarch replacement can be performed more safely than total arch replacement. Rates of distal aortic reoperation were not different between the 2 surgical strategies.

Does high location and thickness of the Wrisberg ligament affect discoid lateral meniscus tear type based on peripheral detachment?

PubMed

Ahn, Jin Hwan; Wang, Joon Ho; Kim, Dong Uk; Lee, Do Kyung; Kim, Jun Ho

2017-12-01

The aim of this study was to evaluate the relationship between discoid lateral meniscus (DLM) types based on peripheral detachment and anatomic features of Wrisberg ligament (WL) such as location and thickness based on magnetic resonance image (MRI). A total of 322 knees in 292 patients were reviewed. Patients were divided into four DLM types according to peripheral detachment: no shift (type 1), anterocentral shift (type 2), posterocentral shift (type 3) and central shift (type 4). We reviewed all MRI concentrating on the presence, location (high or low location), running angle, thickness of WL, and WL/posterior cruciate ligament (PCL) thickness ratio. The relationship between DLM types and anatomic features of WL were analyzed using one-way analysis of variance and chi-square test. According to DLM types based on peripheral detachment, 149 knees were type 1, 38 were type 2, 79 were type 3, and 56 were type 4. Among the 322 knees, 302 (93.8%) had WL on MRI. In DLM patients, type 3 showed a statistically significant (P<0.001) relationship with high location of WL. In addition, type 3 had significantly larger (P<0.0001) running angle of WL, thicker (P<0.0001) WL, and higher (P<0.0001) WL/PCL ratio compared to other types. A high location and thick WL are related to posterocentral shift type of DLM based on peripheral detachment. Based on our results, the high location and thick WL might provide information to surgeons in predicting the direction of peripheral detachment in symptomatic DLM patients. Copyright © 2017 Elsevier B.V. All rights reserved.

In-silico Taxonomic Classification of 373 Genomes Reveals Species Misidentification and New Genospecies within the Genus Pseudomonas

PubMed Central

Tran, Phuong N.; Savka, Michael A.; Gan, Han Ming

2017-01-01

The genus Pseudomonas has one of the largest diversity of species within the Bacteria kingdom. To date, its taxonomy is still being revised and updated. Due to the non-standardized procedure and ambiguous thresholds at species level, largely based on 16S rRNA gene or conventional biochemical assay, species identification of publicly available Pseudomonas genomes remains questionable. In this study, we performed a large-scale analysis of all Pseudomonas genomes with species designation (excluding the well-defined P. aeruginosa) and re-evaluated their taxonomic assignment via in silico genome-genome hybridization and/or genetic comparison with valid type species. Three-hundred and seventy-three pseudomonad genomes were analyzed and subsequently clustered into 145 distinct genospecies. We detected 207 erroneous labels and corrected 43 to the proper species based on Average Nucleotide Identity Multilocus Sequence Typing (MLST) sequence similarity to the type strain. Surprisingly, more than half of the genomes initially designated as Pseudomonas syringae and Pseudomonas fluorescens should be classified either to a previously described species or to a new genospecies. Notably, high pairwise average nucleotide identity (>95%) indicating species-level similarity was observed between P. synxantha-P. libanensis, P. psychrotolerans–P. oryzihabitans, and P. kilonensis- P. brassicacearum, that were previously differentiated based on conventional biochemical tests and/or genome-genome hybridization techniques. PMID:28747902

Dental anomalies inside the cleft region in individuals with nonsyndromic cleft lip with or without cleft palate.

PubMed

Sá, Jamile; Araújo, Luana; Guimarães, Laís; Maranhão, Samário; Lopes, Gabriela; Medrado, Alena; Coletta, Ricardo; Reis, Silvia

2016-01-01

Individuals with nonsyndromic cleft lip with or without cleft palate (NSCL±P) present high frequency of dental anomalies, which may represent complicating factors for dental treatment. The aim of this study was to investigate the prevalence of dental anomalies inside cleft area in a group of Brazilians with NSCL±P. Retrospective analysis of 178 panoramic radiographs of patients aged from 12 to 45 years old and without history of tooth extraction or orthodontic treatment was performed. Association between cleft type and the prevalence of dental anomalies was assessed by chi-square test with a significance level set at p≤ 0.05. Dental anomalies were found in 88.2% (n=157) of the patients. Tooth agenesis (47.1%), giroversion (20%) and microdontia (15.5%) were the most common anomalies. Individuals with unilateral complete cleft lip and palate (CLP, p<0.0001), bilateral complete CLP (p=0.0002) and bilateral incomplete CLP (p< 0.0001) were more affected by tooth agenesis than individuals with other cleft types. The maxillary lateral incisors were the most affected teeth (p<0.0001). The present study revealed a high frequency of dental anomalies inside cleft region in NSCL±P patients, and further demonstrated that patients with unilateral complete CLP and bilateral incomplete CLP were frequently more affected by dental anomalies. Moreover, our results demonstrate that dental anomalies should be considered during dental treatment planning of individuals affected by NSCL±P.

Immunoexpression of p16 in uterine leiomyomas with infarct-type necrosis: an analysis of 35 cases.

PubMed

Ip, Philip P; Lim, Diana; Cheung, Annie N Y; Oliva, Esther

2017-11-01

Uterine leiomyosarcomas frequently show p16 immunoexpression. However, p16 may also be expressed in some benign leiomyoma variants such as leiomyomas with bizarre nuclei and cellular leiomyomas, limiting its utility as a biomarker to distinguish between benign and malignant neoplasms. We investigated p16 expression in leiomyomas with infarct-type necrosis, tumours which may sometimes be misinterpreted as smooth muscle tumours of uncertain malignant potential or even leiomyosarcoma on conventional light microscopy. p16 immunostaining was performed on 35 leiomyomas with infarct-type necrosis and the staining pattern was analysed. Staining was classified as absent, scattered/isolated, <33-, 33-66- or >66%-positive cells, and was assessed in the areas immediately surrounding and distant from the infarct. The median age of patients was 44 years. Seventeen had hormonal/non-hormonal drugs and three were pregnant. The median tumour size was 7.25 cm. The mean mitotic count was 0.9/10 high-power fields. Only one tumour had multifocal mild nuclear atypia. Positive p16 was noted in 34 of 35 (97.2%) tumours. It was typically patchy, and was concentrated in areas immediately surrounding the necrosis. Distant from the necrosis, p16 positivity was seen predominantly in scattered/isolated cells. One tumour without any worrisome microscopic features showed diffuse p16 positivity throughout. Median follow-up was 55 months, and none of the patients experienced any recurrence. p16 expression in benign uterine smooth muscle tumours with infarct-type necrosis is common. The staining is particularly concentrated adjacent to areas of necrosis. It is important to be aware of this potential pitfall when interpreting p16 expression. © 2017 John Wiley & Sons Ltd.

Vitamin D and glycemic control in diabetes mellitus type 2.

PubMed

Kostoglou-Athanassiou, Ifigenia; Athanassiou, Panagiotis; Gkountouvas, Anastasios; Kaldrymides, Philippos

2013-08-01

The extraskeletal effects of vitamin D have attracted considerable interest. Vitamin D deficiency appears to be related to the development of diabetes mellitus type 2 and the metabolic syndrome. Vitamin D may affect glucose homeostasis, vitamin D levels having been found to be inversely related to glycosylated hemoglobin levels in gestational diabetes mellitus. In addition, vitamin D appears to protect from the development of gestational diabetes mellitus. The aim was to study levels of 25-hydroxy vitamin D3 [25(OH)D3] and the relationship between 25(OH)D3 levels and glycemic control in patients with diabetes mellitus type 2. Glycosylated hemoglobin (HbA1c) and 25(OH)D3 levels were measured in a group of 120 diabetes mellitus type 2 patients. The same measurements were performed in a group of 120 control subjects of the same age and sex. 25(OH)D3 was measured by radioimmunoassay and glycosylated hemoglobin (HbA1c) was measured by high-performance liquid chromatography. 25(OH)D3 levels were lower in the diabetes mellitus type 2 patients than in the control group, being 19.26 ± 0.95 ng/ml and 25.49 ± 1.02 ng/ml, in the patient and control groups, respectively (p < 0.001, Student's t-test). 25(OH)D3 levels were found to be inversely associated with HbA1c levels in the diabetic patients (p = 0.008, r (2) = 0.058, linear regression). 25(OH)D3 levels were found to be inversely associated with HbA1c when the patient and control groups were analysed together (p < 0.001, r (2) = 0.086). Vitamin D levels appeared to be lower in diabetes mellitus type 2 patients than in the control group, vitamin D levels being related to glycemic control in diabetes mellitus type 2. These findings may have therapeutic implications as cautious vitamin D supplementation may improve glycemic control in diabetes mellitus type 2.

Deterministic growth of AgTCNQ and CuTCNQ nanowires on large-area reduced graphene oxide films for flexible optoelectronics.

PubMed

Zhang, Shuai; Lu, Zhufeng; Gu, Li; Cai, Liling; Cao, Xuebo

2013-11-22

We describe a synchronous reduction and assembly procedure to directly produce large-area reduced graphene oxide (rGO) films sandwiched by a high density of metal nanoparticles (silver and copper). Further, by using the sandwiched metal NPs as sources, networks consisting of AgTCNQ and CuTCNQ nanowires were deterministically grown from the rGO films, forming structurally and functionally integrated rGO/metal-TCNQ hybrid films with outstanding flexibility, bending endurance, and electrical stability. Interestingly, due to the p-type nature of the rGO film and the n-type nature of the metal-TCNQ NWs, the hybrid films are essentially thin-film p-n junctions which are useful in ubiquitous electronics and optoelectronics. Measurements of the optoelectronic properties demonstrate that the rGO/metal-TCNQ hybrid films exhibit substantial photoconductivity and highly reproducible photoswitching behaviours. The present approach may open the door to the versatile and deterministic integration of functional nanostructures into flexible conducting substrates and provide an important step towards producing low-cost and high-performance soft electronic and optoelectronic devices.

Efficient hydrogen evolution catalysis using ternary pyrite-type cobalt phosphosulphide

NASA Astrophysics Data System (ADS)

Cabán-Acevedo, Miguel; Stone, Michael L.; Schmidt, J. R.; Thomas, Joseph G.; Ding, Qi; Chang, Hung-Chih; Tsai, Meng-Lin; He-Hau, Jr.; Jin, Song

2015-12-01

The scalable and sustainable production of hydrogen fuel through water splitting demands efficient and robust Earth-abundant catalysts for the hydrogen evolution reaction (HER). Building on promising metal compounds with high HER catalytic activity, such as pyrite structure cobalt disulphide (CoS2), and substituting non-metal elements to tune the hydrogen adsorption free energy could lead to further improvements in catalytic activity. Here we present a combined theoretical and experimental study to establish ternary pyrite-type cobalt phosphosulphide (CoPS) as a high-performance Earth-abundant catalyst for electrochemical and photoelectrochemical hydrogen production. Nanostructured CoPS electrodes achieved a geometrical catalytic current density of 10 mA cm-2 at overpotentials as low as 48 mV, with outstanding long-term operational stability. Integrated photocathodes of CoPS on n+-p-p+ silicon micropyramids achieved photocurrents up to 35 mA cm-2 at 0 V versus the reversible hydrogen electrode (RHE), onset photovoltages as high as 450 mV versus RHE, and the most efficient solar-driven hydrogen generation from Earth-abundant systems.

Effect of academic status on outcomes of surgery for rectal cancer.

PubMed

Cagino, Kristen; Altieri, Maria S; Yang, Jie; Nie, Lizhou; Talamini, Mark; Spaniolas, Konstantinos; Denoya, Paula; Pryor, Aurora

2018-06-01

The purpose of our study was to investigate surgical outcomes following advanced colorectal procedures at academic versus community institutions. The SPARCS database was used to identify patients undergoing Abdominoperineal resection (APR) and Low Anterior Resection between 2009 and 2014. Linear mixed models and generalized linear mixed models were used to compare outcomes. Laparoscopic versus open procedures, surgery type, volume status, and stoma formation between academic and community facilities were compared. Higher percentages of laparoscopic surgeries (58.68 vs. 41.32%, p value < 0.0001), more APR surgeries (64.60 vs. 35.40%, p value < 0.0001), more high volume hospitals (69.46 vs. 30.54%, p value < 0.0001), and less stoma formation (48.00 vs. 52.00%, p value < 0.0001) were associated with academic centers. After adjusting for confounding factors, academic facilities were more likely to perform APR surgeries (OR 1.35, 95% CI 1.04-1.74, p value = 0.0235). Minorities and Medicaid patients were more likely to receive care at an academic facility. Stoma formation, open surgery, and APR were associated with longer LOS and higher rate of ED visit and 30-day readmission. Laparoscopy and APR are more commonly performed at academic than community facilities. Age, sex, race, and socioeconomic status affect the facility at which and the type of surgery patients receive, thereby influencing surgical outcomes.

HIF-1α and GLUT-1 Expression in Atypical Endometrial Hyperplasia, Type I and II Endometrial Carcinoma: A Potential Role in Pathogenesis

PubMed Central

Abdou, Asmaa Gaber; Wahed, Moshira Mohammed Abdel; Kassem, Hend Abdou

2016-01-01

Introduction Hypoxia-Inducible Factor 1α (HIF-1α) is one of the major adaptive responses to hypoxia, regulating the activity of glucose transporter -1 (GLUT-1), responsible for glucose uptake. Aim To evaluate the immunohistochemical expression of both HIF-1α and GLUT-1 in type I and II endometrial carcinoma and their correlation with the available clinicopathologic variables in each type. Materials and Methods A retrospective study was conducted on archival blocks diagnosed from pathology department between April 2010 and August 2014 included 9 cases of atypical hyperplasia and 67 cases of endometrial carcinoma. Evaluation of both HIF-1α and GLUT-1 expression using standard immunohistochemical techniques performed on cut sections from selected paraffin embedded blocks. Statistical Analysis Descriptive analysis of the variables and statistical significances were calculated by non-parametric chi-square test using the Statistical Package for the Social Sciences version 12.0 (SPSS). Results HIF-1α was expressed in epithelial (88.9%, 52.2%, 61.2% and 50%) and stromal (33.3%, 74.6%. 71.4% and 83.3%) components of hyperplasia, total cases of EC, type I and II EC, respectively. GLUT-1 was expressed in the epithelial component of 88.9%, 98.5%, 98% and 100% of hyperplasia, total EC cases, type I and II EC, respectively. The necrosis related pattern of epithelial HIF-1α expression was in favour of type II (p=0.018) and grade III (p=0.038). HIF-1α H-score was associated with high apoptosis in both type I and total cases of EC (p=0.04). GLUT-1 H-score was negatively correlated with apoptotic count (p=0.04) and associated with high grade (p=0.003) and advanced stage in total EC (p=0.004). GLUT-1 H-score was correlated with the pattern of HIF-1α staining in all cases of EC (p= 0.04). Conclusion The role of HIF-1α in epithelial cells may differ from that of stromal cells in EC; however they augment the expression of each other supporting the crosstalk between them. The stepwise increase in H- score of GLUT-1 in the studied cases implies its potential role in carcinogenesis of EC. HIF-1α may promote GLUT-1 expression in EC especially surrounding areas of necrosis. The differences between type I and type II EC regarding HIF-1α and GLUT-1 expression may confirm the differences in their aetiopathogenesis. PMID:27437226

HIF-1α and GLUT-1 Expression in Atypical Endometrial Hyperplasia, Type I and II Endometrial Carcinoma: A Potential Role in Pathogenesis.

PubMed

Al-Sharaky, Dalia Rifaat; Abdou, Asmaa Gaber; Wahed, Moshira Mohammed Abdel; Kassem, Hend Abdou

2016-05-01

Hypoxia-Inducible Factor 1α (HIF-1α) is one of the major adaptive responses to hypoxia, regulating the activity of glucose transporter -1 (GLUT-1), responsible for glucose uptake. To evaluate the immunohistochemical expression of both HIF-1α and GLUT-1 in type I and II endometrial carcinoma and their correlation with the available clinicopathologic variables in each type. A retrospective study was conducted on archival blocks diagnosed from pathology department between April 2010 and August 2014 included 9 cases of atypical hyperplasia and 67 cases of endometrial carcinoma. Evaluation of both HIF-1α and GLUT-1 expression using standard immunohistochemical techniques performed on cut sections from selected paraffin embedded blocks. Descriptive analysis of the variables and statistical significances were calculated by non-parametric chi-square test using the Statistical Package for the Social Sciences version 12.0 (SPSS). HIF-1α was expressed in epithelial (88.9%, 52.2%, 61.2% and 50%) and stromal (33.3%, 74.6%. 71.4% and 83.3%) components of hyperplasia, total cases of EC, type I and II EC, respectively. GLUT-1 was expressed in the epithelial component of 88.9%, 98.5%, 98% and 100% of hyperplasia, total EC cases, type I and II EC, respectively. The necrosis related pattern of epithelial HIF-1α expression was in favour of type II (p=0.018) and grade III (p=0.038). HIF-1α H-score was associated with high apoptosis in both type I and total cases of EC (p=0.04). GLUT-1 H-score was negatively correlated with apoptotic count (p=0.04) and associated with high grade (p=0.003) and advanced stage in total EC (p=0.004). GLUT-1 H-score was correlated with the pattern of HIF-1α staining in all cases of EC (p= 0.04). The role of HIF-1α in epithelial cells may differ from that of stromal cells in EC; however they augment the expression of each other supporting the crosstalk between them. The stepwise increase in H- score of GLUT-1 in the studied cases implies its potential role in carcinogenesis of EC. HIF-1α may promote GLUT-1 expression in EC especially surrounding areas of necrosis. The differences between type I and type II EC regarding HIF-1α and GLUT-1 expression may confirm the differences in their aetiopathogenesis.

Medium band gap polymer based solution-processed high-κ composite gate dielectrics for ambipolar OFET

NASA Astrophysics Data System (ADS)

Canımkurbey, Betül; Unay, Hande; Çakırlar, Çiğdem; Büyükköse, Serkan; Çırpan, Ali; Berber, Savas; Altürk Parlak, Elif

2018-03-01

The authors present a novel ambipolar organic filed-effect transistors (OFETs) composed of a hybrid dielectric thin film of Ta2O5:PMMA nanocomposite material, and solution processed poly(selenophene, benzotriazole and dialkoxy substituted [1,2-b:4, 5-b‧] dithiophene (P-SBTBDT)-based organic semiconducting material as the active layer of the device. We find that the Ta2O5:PMMA insulator shows n-type conduction character, and its combination with the p-type P-SBTBDT organic semiconductor leads to an ambipolar OFET device. Top-gated OFETs were fabricated on glass substrate consisting of interdigitated ITO electrodes. P-SBTBDT-based material was spin coated on the interdigitated ITO electrodes. Subsequently, a solution processed Ta2O5:PMMA nanocomposite material was spin coated, thereby creating the gate dielectric layer. Finally, as a gate metal, an aluminum layer was deposited by thermal evaporation. The fabricated OFETs exhibited an ambipolar performance with good air-stability, high field-induced current and relatively high electron and hole mobilities although Ta2O5:PMMA nanocomposite films have slightly higher leakage current compared to the pure Ta2O5 films. Dielectric properties of the devices with different ratios of Ta2O5:PMMA were also investigated. The dielectric constant varied between 3.6 and 5.3 at 100 Hz, depending on the Ta2O5:PMMA ratio.

High performance polypyrrole coating for corrosion protection and biocidal applications

NASA Astrophysics Data System (ADS)

Nautiyal, Amit; Qiao, Mingyu; Cook, Jonathan Edwin; Zhang, Xinyu; Huang, Tung-Shi

2018-01-01

Polypyrrole (PPy) coating was electrochemically synthesized on carbon steel using sulfonic acids as dopants: p-toluene sulfonic acid (p-TSA), sulfuric acid (SA), (±) camphor sulfonic acid (CSA), sodium dodecyl sulfate (SDS), and sodium dodecylbenzene sulfonate (SDBS). The effect of acidic dopants (p-TSA, SA, CSA) on passivation of carbon steel was investigated by linear potentiodynamic and compared with morphology and corrosion protection performance of the coating produced. The types of the dopants used were significantly affecting the protection efficiency of the coating against chloride ion attack on the metal surface. The corrosion performance depends on size and alignment of dopant in the polymer backbone. Both p-TSA and SDBS have extra benzene ring that stack together to form a lamellar sheet like barrier to chloride ions thus making them appropriate dopants for PPy coating in suppressing the corrosion at significant level. Further, adhesion performance was enhanced by adding long chain carboxylic acid (decanoic acid) directly in the monomer solution. In addition, PPy coating doped with SDBS displayed excellent biocidal abilities against Staphylococcus aureus. The polypyrrole coatings on carbon steels with dual function of anti-corrosion and excellent biocidal properties shows great potential application in the industry for anti-corrosion/antimicrobial purposes.

Community structures and population dynamics of "Candidatus Accumulibacter" in activated sludges of wastewater treatment plants using ppk1 as phylogenetic marker.

PubMed

Zeng, Wei; Zhang, Limin; Fan, Pengchao; Guo, Jingjing; Peng, Yongzhen

2018-05-01

Candidatus Accumulibacter has been identified as dominant polyphosphate-accumulating organisms (PAOs) in enhanced biological phosphorus (P) removal (EBPR) from wastewater. This study revealed the relevance of community structure, abundance and seasonal population dynamics of Candidatus Accumulibacter to process operation of wastewater treatment plants (WWTPs) in China using ppk1 gene as phylogenetic marker. All sludge samples had properties of denitrifying P removal using nitrate as an electron acceptor. Accumulibacter abundance in the anaerobic-anoxic-oxic (A 2 O) process was the highest (26% of total bacteria), and higher in winter than in summer with a better EBPR performance. Type-II was the dominant Accumulibacter in all processes, and type-I accounted for a small proportion of total Accumulibacter. The abundance of Clade-IIC as the most dominant clade reached 2.59×10 9 cells/g MLSS and accounted for 87.3% of total Accumulibacter. Clade IIC mainly contributed to denitrifying P removal. Clades IIA, IIC and IID were found in all processes, while clade-IIF was only found in oxidation ditch process through phylogenetic analysis. High proportion of clade IID to total Accumulibacter led to poor performance of aerobic P-uptake in inverted A 2 O process. Therefore, Accumulibacter clades in WWTPs were diverse, and EBPR performance was closely related to the clade-level community structures and abundances of Accumulibacter. Copyright © 2017. Published by Elsevier B.V.

Prognostic role of pretreatment blood neutrophil-to-lymphocyte ratio in advanced cancer survivors: A systematic review and meta-analysis of 66 cohort studies.

PubMed

Mei, Zubing; Shi, Lu; Wang, Bo; Yang, Jizhen; Xiao, Zhihong; Du, Peixin; Wang, Qingming; Yang, Wei

2017-07-01

Neutrophil-to-lymphocyte ratio (NLR) is crucial for the incidence and mortality of various tumors. However, little is known on NLR and its association with prognosis in advanced tumors. Here we performed a meta-analysis to establish the prognostic significance of pretreatment blood NLR for advanced tumors. A systematic literature search through April 2016 was performed to evaluate the association between pretreatment blood NLR and overall survival (OS) or progression-free survival (PFS) in patients with advanced tumors. Data were extracted from studies reporting hazard ratios (HRs) and 95% confidence interval (CI) and pooled using the Mantel-Haenszel random-effect model. Sixty-six studies with a total of 24536 individuals were included in the meta-analysis. Pooled analyses revealed that elevated pretreatment NLR was associated with worse OS (HR 1.70, 95% CI 1.57-1.84, P<0.001) and PFS (HR 1.61, 95% CI 1.42-1.82, P<0.001) in advanced tumors. Subgroup analysis stratified by tumor type demonstrated that pancreatic cancer patients with high pretreatment NLR had the worst OS (HR 1.94, 95% CI 1.55-2.54, P<0.001) and colorectal cancer with the worst PFS (HR 1.74, 95% CI 1.04-2.90, P<0.001). When stratified by cut-off value for NLR, we found that cut-off value being five indicated the worst PFS (HR 2.23, 95% CI 1.54-3.23, P=0.019). Overall, high pretreatment blood NLR could be an adverse prognostic indicator for advanced tumor. Large-scale prospective studies investigating its survival outcomes in specific cancer type are strongly advocated. Copyright © 2017 Elsevier Ltd. All rights reserved.

Production of cyathane type secondary metabolites by submerged cultures of Hericium erinaceus and evaluation of their antibacterial activity by direct bioautography.

PubMed

Shen, T; Morlock, G; Zorn, H

2015-01-01

Fungi of the phylum Basidiomycota are well-known to form a broad spectrum of biologically active secondary metabolites, especially low molecular weight compounds such as terpenoids. Hericium erinaceus produces various cyathane type diterpenoids including erinacines. However, no quantitative data and production kinetics have been reported on the biosynthesis of the erinacines C and P in submerged cultures. In the present study, the production of erinacine C was optimized, and the product formation kinetics as well as the antimicrobial activity were studied by high-performance liquid chromatography (HPLC), high-performance thin-layer chromatography (HPTLC) and direct bioautography. Oatmeal and Edamin ® K were identified to be crucial media components for an efficient production of erinacine C. The highest concentrations of erinacine C were obtained in the optimized culture medium on the 9 th culture day (approximately 260 mg L -1 ). The production of erinacine P was strongly time dependent. The maximum concentration of erinacine P of 184 mg L -1 was observed on the third culture day. Afterwards, the concentrations of erinacine P decreased while the concentrations of erinacine C steadily increased. Comparable results were obtained by HPTLC with UV detection and HPLC with diode-array detection (DAD) analyses. Direct bioautography allowed for an additional analysis of the antimicrobial activity of the secondary metabolites. The C and N sources oatmeal and Edamin ® K induced the formation of erinacine C. Detailed product formation kinetics of the erinacines C and P have been reported for the first time. HPTLC combined with the Aliivibrio fischeri bioassay allowed for an instant detection of cyathane diterpenoids in crude extracts and for an evaluation of the antimicrobial activity of the secondary metabolites directly on the plate.

MR Imaging-derived Oxygen Metabolism and Neovascularization Characterization for Grading and IDH Gene Mutation Detection of Gliomas.

PubMed

Stadlbauer, Andreas; Zimmermann, Max; Kitzwögerer, Melitta; Oberndorfer, Stefan; Rössler, Karl; Dörfler, Arnd; Buchfelder, Michael; Heinz, Gertraud

2017-06-01

Purpose To explore the diagnostic performance of physiological magnetic resonance (MR) imaging of oxygen metabolism and neovascularization activity for grading and characterization of isocitrate dehydrogenase (IDH) gene mutation status of gliomas. Materials and Methods This retrospective study had institutional review board approval; written informed consent was obtained from all patients. Eighty-three patients with histopathologically proven glioma (World Health Organization [WHO] grade II-IV) were examined with quantitative blood oxygen level-dependent imaging and vascular architecture mapping. Biomarker maps of neovascularization activity (microvessel radius, microvessel density, and microvessel type indicator [MTI]) and oxygen metabolism (oxygen extraction fraction [OEF] and cerebral metabolic rate of oxygen [CMRO 2 ]) were calculated. Receiver operating characteristic analysis was used to determine diagnostic performance for grading and detection of IDH gene mutation status. Results Low-grade (WHO grade II) glioma showed areas with increased OEF (+18%, P < .001, n = 20), whereas anaplastic glioma (WHO grade III) and glioblastoma (WHO grade IV) showed decreased OEF when compared with normal brain tissue (-54% [P < .001, n = 21] and -49% [P < .001, n = 41], respectively). This allowed clear differentiation between low- and high-grade glioma (area under the receiver operating characteristic curve [AUC], 1) for the patient cohort. MTI had the highest diagnostic performance (AUC, 0.782) for differentiation between gliomas of grades III and IV among all biomarkers. CMRO 2 was decreased (P = .037) in low-grade glioma with a mutated IDH gene, and MTI was significantly increased in glioma grade III with IDH mutation (P = .013) when compared with the IDH wild-type counterparts. CMRO 2 showed the highest diagnostic performance for IDH gene mutation detection in low-grade glioma (AUC, 0.818) and MTI in high-grade glioma (AUC, 0.854) and for all WHO grades (AUC, 0.899) among all biomarkers. Conclusion MR imaging-derived oxygen metabolism and neovascularization characterization may be useful for grading and IDH mutation detection of gliomas and requires only 7 minutes of extra imaging time. © RSNA, 2016 Online supplemental material is available for this article.

Continuous moderate-intensity exercise with or without intermittent high-intensity work: effects on acute and late glycaemia in athletes with Type 1 diabetes mellitus.

PubMed

Iscoe, K E; Riddell, M C

2011-07-01

Individuals with Type 1 diabetes mellitus are susceptible to hypoglycaemia during and after continuous moderate-intensity exercise, but hyperglycaemia during intermittent high-intensity exercise. The combination of both forms of exercise may have a moderating effect on glycaemia in recovery. The aims of this study were to compare the physiological responses and associated glycaemic changes to continuous moderate-intensity exercise vs. continuous moderate-intensity exercise + intermittent high-intensity exercise in athletes with Type 1 diabetes. Interstitial glucose levels were measured in a blinded fashion in 11 trained athletes with Type 1 diabetes during two sedentary days and during 2 days in which 45 min of afternoon continuous moderate-intensity exercise occurred either with or without intermittent high-intensity exercise. The total amount of work performed and the duration of exercise was identical between sessions. During exercise, heart rate, respiratory exchange ratio, oxygen utilization, ventilation and blood lactate levels were higher during continuous moderate-intensity + intermittent high-intensity exercise vs. continuous moderate-intensity exercise (all P < 0.05). Despite these marked cardiorespiratory differences between trials, there was no difference in the reduction of interstitial glucose or plasma glucose levels between the exercise trials. Nocturnal glucose levels were higher in continuous moderate-intensity + intermittent high-intensity exercise and in sedentary vs. continuous moderate-intensity exercise (P < 0.05). Compared with continuous moderate-intensity exercise alone, continuous moderate-intensity + intermittent high-intensity exercise was associated with less post-exercise hypoglycaemia (5.2 vs. 1.5% of the time spent with glucose < 4.0 mmol/l) and more post-exercise hyperglycaemia (33.8 vs. 20.4% of time > 11.0 mmol/l). Although the decreases in glucose level during continuous moderate-intensity exercise and continuous moderate-intensity + intermittent high-intensity exercise are similar, the latter form of exercise protects against nocturnal hypoglycaemia in athletes with Type 1 diabetes. © 2011 The Authors. Diabetic Medicine © 2011 Diabetes UK.

How localized acceptors limit p-type conductivity in GaN

NASA Astrophysics Data System (ADS)

Lyons, John L.

2013-03-01

Despite the impressive development of GaN as an optoelectronic material, p-type conductivity is still limited. Only a single acceptor impurity, magnesium, is known to lead to p-type GaN. But Mg is far from a well-behaved acceptor. Hydrogen is known to passivate Mg, necessitating a post-growth anneal for acceptor activation. In addition, the ionization energy is quite large (~ 200 meV in GaN), meaning only a few percent of Mg acceptors are ionized at room temperature. Thus, hole conductivity is limited, and high concentrations of Mg are required to achieve moderately p-type GaN. Other acceptor impurities have not proven to be effective p-type dopants, for reasons that are still unresolved. Using advanced first-principles calculations based on a hybrid functional, we investigate the electrical and optical properties of the isolated Mg acceptor and its complexes with hydrogen in GaN, InN, and AlN.[2] We employ a technique that overcomes the band-gap-problem of traditional density functional theory, and allows for quantitative predictions of acceptor ionization energies and optical transition energies. Our results allow us to explain the deep or shallow nature of the Mg acceptor and its relation to the optical signals observed in Mg-doped GaN. We also revisit the properties of other group-II acceptors in GaN. We find that all cation-site acceptors show behavior similar to MgGa, and lead to highly localized holes. The ZnGa and BeGa acceptors have ionization energies that are even larger than that of Mg, making them ineffective dopants. All acceptors cause large lattice distortions in their neutral charge state, in turn leading to deep, broad luminescence signals that can serve as a means of experimentally verifying the deep nature of these acceptors. This work was performed in collaboration with Audrius Alkauskas, Anderson Janotti, and Chris G. Van de Walle. It was supported by the NSF and by the Solid State Lighting and Energy Center at UCSB.

Oxide semiconductor thin-film transistors: a review of recent advances.

PubMed

Fortunato, E; Barquinha, P; Martins, R

2012-06-12

Transparent electronics is today one of the most advanced topics for a wide range of device applications. The key components are wide bandgap semiconductors, where oxides of different origins play an important role, not only as passive component but also as active component, similar to what is observed in conventional semiconductors like silicon. Transparent electronics has gained special attention during the last few years and is today established as one of the most promising technologies for leading the next generation of flat panel display due to its excellent electronic performance. In this paper the recent progress in n- and p-type oxide based thin-film transistors (TFT) is reviewed, with special emphasis on solution-processed and p-type, and the major milestones already achieved with this emerging and very promising technology are summarizeed. After a short introduction where the main advantages of these semiconductors are presented, as well as the industry expectations, the beautiful history of TFTs is revisited, including the main landmarks in the last 80 years, finishing by referring to some papers that have played an important role in shaping transparent electronics. Then, an overview is presented of state of the art n-type TFTs processed by physical vapour deposition methods, and finally one of the most exciting, promising, and low cost but powerful technologies is discussed: solution-processed oxide TFTs. Moreover, a more detailed focus analysis will be given concerning p-type oxide TFTs, mainly centred on two of the most promising semiconductor candidates: copper oxide and tin oxide. The most recent data related to the production of complementary metal oxide semiconductor (CMOS) devices based on n- and p-type oxide TFT is also be presented. The last topic of this review is devoted to some emerging applications, finalizing with the main conclusions. Related work that originated at CENIMAT|I3N during the last six years is included in more detail, which has led to the fabrication of high performance n- and p-type oxide transistors as well as the fabrication of CMOS devices with and on paper. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tectono-metamorphic evolution of high-P/T and low-P/T metamorphic rocks in the Tia Complex, southern New England Fold Belt, eastern Australia: Insights from K-Ar chronology

NASA Astrophysics Data System (ADS)

Fukui, Shiro; Tsujimori, Tatsuki; Watanabe, Teruo; Itaya, Tetsumaru

2012-10-01

The Tia Complex in the southern New England Fold Belt is a poly-metamorphosed Late Paleozoic accretionary complex. It consists mainly of high-P/low-T type pumpellyite-actinolite facies (rare blueschist facies) schists, phyllite and serpentinite (T = 300 °C and P = 5 kbar), and low-P/high-T type amphibolite facies schist and gneiss (T = 600 °C and P < 5 kbar) associated with granodioritic plutons (Tia granodiorite). White mica and biotite K-Ar ages distinguish Carboniferous subduction zone metamorphism and Permian granitic intrusions, respectively. The systematic K-Ar age mapping along a N-S traverse of the Tia Complex exhibits a gradual change. The white mica ages become younger from the lowest-grade zone (339 Ma) to the highest-grade zone (259 Ma). In contrast, Si content of muscovite changes drastically only in the highest-grade zone. The regional changes of white mica K-Ar ages and chemical compositions of micas indicate argon depletion from precursor high-P/low-T type phengitic white mica during the thermal overprinting and recrystallization by granitoids intrusions. Our new K-Ar ages and available geological data postulate a model of the eastward rollback of a subduction zone in Early Permian. The eastward shift of a subduction zone system and subsequent magmatic activities of high-Mg andesite and adakite might explain formation of S-type granitoids (Hillgrove suite) and coeval low-P/high-T type metamorphism in the Tia Complex.

Codoping in SnTe: Enhancement of Thermoelectric Performance through Synergy of Resonance Levels and Band Convergence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tan, Gangjian; Shi, Fengyuan; Hao, Shiqiang

2015-04-22

We report a significant enhancement of the thermoelectric performance of p-type SnTe over a broad temperature plateau with a peak ZT value of similar to 1.4 at 923 K through In/Cd codoping and a CdS nanostructuring approach. Indium and cadmium play different but complementary roles in modifying the valence band structure of SnTe. Specifically, In-doping introduces resonant levels inside the valence bands, leading to a considerably improved Seebeck coefficient at low temperature. Cd-doping, however, increases the Seebeck coefficient of SnTe remarkably in the mid- to high-temperature region via a convergence of the light and heavy hole bands and an enlargementmore » of the band gap. Combining the two dopants in SnTe yields enhanced Seebeck coefficient and power factor over a wide temperature range due to the synergy of resonance levels and valence band convergence, as demonstrated by the Pisarenko plot and supported by first-principles band structure calculations. Moreover, these codoped samples can be hierarchically structured on all scales (atomic point defects by doping, nanoscale precipitations by CdS nanostructuring, and mesoscale grains by SPS treatment) to achieve highly effective phonon scattering leading to strongly reduced thermal conductivities. In addition to the high maximum ZT the resultant large average ZT of similar to 0.8 between 300 and 923 K makes SnTe an attractive p-type material for high-temperature thermoelectric power generation.« less

Correlations of high-sensitivity C-reactive protein and atherosclerosis in Japanese type 2 diabetic patients.

PubMed

Anan, Futoshi; Masaki, Takayuki; Umeno, Yoshikazu; Iwao, Tetsu; Yonemochi, Hidetoshi; Eshima, Nobuoki; Saikawa, Tetsunori; Yoshimatsu, Hironobu

2007-09-01

The elevated level of high-sensitivity C-reactive protein (HSCRP) and aortic stiffness are associated with high mortality in type 2 diabetic patients. We tested the hypothesis that the HSCRP correlates with aortic stiffness and insulin resistance in type 2 diabetic patients. The study consisted of 46 Japanese patients with type 2 diabetes and high HSCRP group (0.3-1.0 mg/dl, age: 57+/-5 years, mean+/-s.d.) and a control group of 55 age-matched patients with low HSCRP group (<0.3 mg/dl, 57+/-6 years). Brachial-ankle pulse wave velocity (BaPWV) was measured by automatic oscillometric method and was used as an index of atherosclerosis. The body mass index (BMI) values (P<0.05) and waist circumferences (P<0.0005) and the waist-to-hip ratios (P<0.05) were higher in the high HSCRP group than in the low HSCRP group. The BaPWV was higher in the high HSCRP group than in the low HSCRP group (P<0.0001). Fasting plasma glucose (FPG; P<0.005) and insulin concentrations (P<0.0001), and the homeostasis model assessment (HOMA) index (P<0.0001), were higher in the high HSCRP group than in the low HSCRP group. Multiple regression analysis showed that HSCRP levels were independently predicted by BaPWV and HOMA index. Our results indicate that the elevated level of HSCRP in Japanese patients with type 2 diabetes is characterized by increased aortic stiffness and insulin resistance, and that the BaPWV and HOMA index are independent predictors of HSCRP.

Development of High-Performance eSWIR HgCdTe-Based Focal-Plane Arrays on Silicon Substrates

NASA Astrophysics Data System (ADS)

Park, J. H.; Pepping, J.; Mukhortova, A.; Ketharanathan, S.; Kodama, R.; Zhao, J.; Hansel, D.; Velicu, S.; Aqariden, F.

2016-09-01

We report the development of high-performance and low-cost extended short-wavelength infrared (eSWIR) focal-plane arrays (FPAs) fabricated from molecular beam epitaxial (MBE)-grown HgCdTe on Si-based substrates. High-quality n-type eSWIR HgCdTe (cutoff wavelength ˜2.68 μm at 77 K, electron carrier concentration 5.82 × 1015 cm-3) layers were grown on CdTe/Si substrates by MBE. High degrees of uniformity in composition and thickness were demonstrated over three-inch areas, and low surface defect densities (voids 9.56 × 101 cm-2, micro-defects 1.67 × 103 cm-2) were measured. This material was used to fabricate 320 × 256 format, 30 μm pitch FPAs with a planar device architecture using arsenic implantation to achieve p-type doping. The dark current density of test devices showed good uniformity between 190 K and room temperature, and high-quality eSWIR imaging from hybridized FPAs was obtained with a median dark current density of 2.63 × 10-7 A/cm2 at 193 K with a standard deviation of 1.67 × 10-7 A/cm2.

Carrier removal and defect behavior in p-type InP

NASA Technical Reports Server (NTRS)

Weinberg, I.; Swartz, C. K.; Drevinsky, P. J.

1992-01-01

A simple expression, obtained from the rate equation for defect production, was used to relate carrier removal to defect production and hole trapping rates in p-type InP after irradiation by 1-MeV electrons. Specific contributions to carrier removal from defect levels H3, H4, and H5 were determined from combined deep-level transient spectroscopy (DLTS) and measured carrier concentrations. An additional contribution was attributed to one or more defects not observed by the present DLTS measurements. The high trapping rate observed for H5 suggests that this defect, if present in relatively high concentration, could be dominant in p-type InP.

The prediction of a new high-pressure phase of hafnia using first-principles computations

NASA Astrophysics Data System (ADS)

Al-Khatatbeh, Y.; Tarawneh, K.; Hamad, B.

2018-02-01

Using density functional theory (DFT) calculations, we predicted a new high- pressure phase of hafnia (HfO2). We found the hexagonal phase (Ni2In-type structure; space group: P63 /mmc) to be the stable phase at ultrahigh pressures greater than ~386 GPa. Our findings are consistent with recent calculations performed on the similar dioxide ZrO2 [M. Durandurdu, J. Solid State Chem. 230, 233 (2015)] where this phase has been claimed to be the most stable at pressures greater than 380 GPa. The Birch-Murnaghan equation of state (BM- EOS) of the new phase shows that this phase is more compressible and less dense than Fe2P-type phase. Additionally, the hardness calculations using a scaling model confirmed that our newly predicted phase has a similar hardness compared to the other HfO2 phases, indicating that none of the HfO2 phases can be considered to be superhard.

Indium Phosphide Window Layers for Indium Gallium Arsenide Solar Cells

NASA Technical Reports Server (NTRS)

Jain, Raj K.

2005-01-01

Window layers help in reducing the surface recombination at the emitter surface of the solar cells resulting in significant improvement in energy conversion efficiency. Indium gallium arsenide (In(x)Ga(1-x)As) and related materials based solar cells are quite promising for photovoltaic and thermophotovoltaic applications. The flexibility of the change in the bandgap energy and the growth of InGaAs on different substrates make this material very attractive for multi-bandgap energy, multi-junction solar cell approaches. The high efficiency and better radiation performance of the solar cell structures based on InGaAs make them suitable for space power applications. This work investigates the suitability of indium phosphide (InP) window layers for lattice-matched In(0.53)Ga(0.47)As (bandgap energy 0.74 eV) solar cells. We present the first data on the effects of the p-type InP window layer on p-on-n lattice-matched InGaAs solar cells. The modeled quantum efficiency results show a significant improvement in the blue region with the InP window. The bare InGaAs solar cell performance suffers due to high surface recombination velocity (10(exp 7) cm/s). The large band discontinuity at the InP/InGaAs heterojunction offers a great potential barrier to minority carriers. The calculated results demonstrate that the InP window layer effectively passivates the solar cell front surface, hence resulting in reduced surface recombination and therefore, significantly improving the performance of the InGaAs solar cell.

Type-II Superlattice for High Performance LWIR Detectors

DTIC Science & Technology

2008-05-15

Superlattice for High Performance LWIR Detectors 5. FUNDING NUMBERS F49620-03-1-0436 6. AUTHOR(S) M. Razeghi 7. PERFORMING ORGANIZATION NAME(S...298 (Rcv.2-89) Prescribed by ANSI Std. 239-18 298-102 Final Technical Report Type-II Superlattice for High Performance LWIR Detectors Contract No...Short-period InAs/GaSb type-II superlattices for mid- infrared detectors . Physica E: Low- dimensional Systems and Nanostructures, 2006.

Improving the Performance of Layered Oxide Cathode Materials with Football-Like Hierarchical Structure for Na-Ion Batteries by Incorporating Mg2+ into Vacancies in Na-Ion Layers.

PubMed

Li, Zheng-Yao; Wang, Huibo; Chen, Dongfeng; Sun, Kai; Yang, Wenyun; Yang, Jinbo; Liu, Xiangfeng; Han, Songbai

2018-04-09

The development of advanced cathode materials is still a great interest for sodium-ion batteries. The feasible commercialization of sodium-ion batteries relies on the design and exploitation of suitable electrode materials. This study offers a new insight into material design to exploit high-performance P2-type cathode materials for sodium-ion batteries. The incorporation of Mg 2+ into intrinsic Na + vacancies in Na-ion layers can lead to a high-performance P2-type cathode material for sodium-ion batteries. The materials prepared by the coprecipitation approach show a well-defined morphology of secondary football-like hierarchical structures. Neutron power diffraction and refinement results demonstrate that the incorporation of Mg 2+ into intrinsic vacancies can enlarge the space for Na-ion diffusion, which can increase the d-spacing of the (0 0 2) peak and the size of slabs but reduce the chemical bond length to result in an enhanced rate capability and cycling stability. The incorporation of Mg 2+ into available vacancies and a unique morphology make Na 0.7 Mg 0.05 Mn 0.8 Ni 0.1 Co 0.1 O 2 a promising cathode, which can be charged and discharged at an ultra-high current density of 2000 mA g -1 with an excellent specific capacity of 60 mAh g -1 . This work provides a new insight into the design of electrode materials for sodium-ion batteries. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

High-Performance Silicon-Germanium-Based Thermoelectric Modules for Gas Exhaust Energy Scavenging

NASA Astrophysics Data System (ADS)

Romanjek, K.; Vesin, S.; Aixala, L.; Baffie, T.; Bernard-Granger, G.; Dufourcq, J.

2015-06-01

Some of the energy used in transportation and industry is lost as heat, often at high-temperatures, during conversion processes. Thermoelectricity enables direct conversion of heat into electricity, and is an alternative to the waste-heat-recovery technology currently used, for example turbines and other types of thermodynamic cycling. The performance of thermoelectric (TE) materials and modules has improved continuously in recent decades. In the high-temperature range ( T hot side > 500°C), silicon-germanium (SiGe) alloys are among the best TE materials reported in the literature. These materials are based on non-toxic elements. The Thermoelectrics Laboratory at CEA (Commissariat à l'Energie Atomique et aux Energies Alternatives) has synthesized n and p-type SiGe pellets, manufactured TE modules, and integrated these into thermoelectric generators (TEG) which were tested on a dedicated bench with hot air as the source of heat. SiGe TE samples of diameter 60 mm were created by spark-plasma sintering. For n-type SiGe doped with phosphorus the peak thermoelectric figure of merit reached ZT = 1.0 at 700°C whereas for p-type SiGe doped with boron the peak was ZT = 0.75 at 700°C. Thus, state-of-the-art conversion efficiency was obtained while also achieving higher production throughput capacity than for competing processes. A standard deviation <4% in the electrical resistance of batches of ten pellets of both types was indicative of high reproducibility. A silver-paste-based brazing technique was used to assemble the TE elements into modules. This assembly technique afforded low and repeatable electrical contact resistance (<3 nΩ m2). A test bench was developed for measuring the performance of TE modules at high temperatures (up to 600°C), and thirty 20 mm × 20 mm TE modules were produced and tested. The results revealed the performance was reproducible, with power output reaching 1.9 ± 0.2 W for a 370 degree temperature difference. When the temperature difference was increased to 500°C, electrical power output increased to >3.6 W. An air-water heat exchanger was developed and 30 TE modules were clamped and connected electrically. The TEG was tested under vacuum on a hot-air test bench. The measured output power was 45 W for an air flow of 16 g/s at 750°C. The hot surface of the TE module reached 550°C under these conditions. Silicon-germanium TE modules can survive such temperatures, in contrast with commercial modules based on bismuth telluride, which are limited to 400°C.

High-Performance Three-Stage Cascade Thermoelectric Devices with 20% Efficiency

NASA Astrophysics Data System (ADS)

Cook, B. A.; Chan, T. E.; Dezsi, G.; Thomas, P.; Koch, C. C.; Poon, J.; Tritt, T.; Venkatasubramanian, R.

2015-06-01

The use of advanced materials has resulted in a significant improvement in thermoelectric device conversion efficiency. Three-stage cascade devices were assembled, consisting of nano-bulk Bi2Te3-based materials on the cold side, PbTe and enhanced TAGS-85 [(AgSbTe2)15(GeTe)85] for the mid-stage, and half-Heusler alloys for the high-temperature top stage. In addition, an area aspect ratio optimization process was applied in order to account for asymmetric thermal transport down the individual n- and p-legs. The n- and p-type chalcogenide alloy materials were prepared by high-energy mechanical ball-milling and/or cryogenic ball-milling of elementary powders, with subsequent consolidation by high-pressure uniaxial hot-pressing. The low-temperature stage materials, nano-bulk Bi2Te3- x Sb x and Bi2Te3- x Se x , exhibit a unique mixture of nanoscale features that leads to an enhanced Seebeck coefficient and reduced lattice thermal conductivity, thereby achieving an average ZT of ~1.26 and ~1.7 in the 27°C to 100°C range for the n-type and p-type materials, respectively. Also, the addition of small amounts of selected rare earth elements has been shown to improve the ZT of TAGS-85 by 25%, compared with conventional or neat TAGS-85, resulting in a ZT = 1.5 at 400°C. The incorporation of these improved materials resulted in a peak device conversion efficiency of ~20% at a temperature difference of 750°C when corrected for radiation heat losses and thermal conduction losses through the lead wires. These high-efficiency results were shown to be reproducible across multiple cascade devices.

Passive-bending, short-type single-balloon enteroscope for endoscopic retrograde cholangiopancreatography in Roux-en-Y anastomosis patients.

PubMed

Yamauchi, Hiroshi; Kida, Mitsuhiro; Okuwaki, Kosuke; Miyazawa, Shiro; Iwai, Tomohisa; Tokunaga, Shuko; Takezawa, Miyoko; Imaizumi, Hiroshi; Koizumi, Wasaburo

2015-02-07

To evaluate short-type-single-balloon enteroscope (SBE) with passive-bending, high-force transmission functions for endoscopic retrograde cholangiopancreatography (ERCP) in patients with Roux-en-Y anastomosis. Short-type SBE with this technology (SIF-Y0004-V01; working length, 1520 mm; channel diameter, 3.2 mm) was used to perform 50 ERCP procedures in 37 patients with Roux-en-Y anastomosis. The rate of reaching the blind end, time required to reach the blind end, diagnostic and therapeutic success rates, and procedure time and complications were studied retrospectively and compared with the results of 34 sessions of ERCP performed using a short-type SBE without this technology (SIF-Y0004; working length, 1520 mm; channel diameter, 3.2 mm) in 25 patients. The rate of reaching the blind end was 90% with SIF-Y0004-V01 and 91% with SIF-Y0004 (P = 0.59). The median time required to reach the papilla was significantly shorter with SIF-Y0004-V01 than with SIF-Y0004 (16 min vs 24 min, P = 0.04). The diagnostic success rate was 93% with SIF-Y0004-V01 and 84% with SIF-Y0004 (P = 0.17). The therapeutic success rate was 95% with SIF-Y0004-V01 and 96% with SIF-Y0004 (P = 0.68). The median procedure time was 40 min with SIF-Y0004-V01 and 36 min with SIF-Y0004 (P = 0.50). The incidence of hyperamylasemia was 6.0% in the SIF-Y0004-V01 group and 14.7% in the SIF-Y0004 group (P = 0.723). The incidence of pancreatitis was 0% in the SIF-Y0004-V01 group and 5.9% in the SIF-Y0004 group (P > 0.999). The incidence of gastrointestinal perforation was 2.0% (1/50) in the SIF-Y0004-V01 group and 2.9% (1/34) in the SIF-Y0004 group (P > 0.999). SIF-Y0004-V01 is useful for ERCP in patients with Roux-en-Y anastomosis and may reduce the time required to reach the blind end.

Application of neutron transmutation doping method to initially p-type silicon material.

PubMed

Kim, Myong-Seop; Kang, Ki-Doo; Park, Sang-Jun

2009-01-01

The neutron transmutation doping (NTD) method was applied to the initially p-type silicon in order to extend the NTD applications at HANARO. The relationship between the irradiation neutron fluence and the final resistivity of the initially p-type silicon material was investigated. The proportional constant between the neutron fluence and the resistivity was determined to be 2.3473x10(19)nOmegacm(-1). The deviation of the final resistivity from the target for almost all the irradiation results of the initially p-type silicon ingots was at a range from -5% to 2%. In addition, the burn-up effect of the boron impurities, the residual (32)P activity and the effect of the compensation characteristics for the initially p-type silicon were studied. Conclusively, the practical methodology to perform the neutron transmutation doping of the initially p-type silicon ingot was established.

High oxidative capacity and type IIx fibre content in springbok and fallow deer skeletal muscle suggest fast sprinters with a resistance to fatigue

PubMed Central

Curry, Jennifer Wendy; Hohl, Rodrigo; Noakes, Timothy David; Kohn, Tertius Abraham

2012-01-01

SUMMARY Some wild antelopes are fast sprinters and more resistant to fatigue than others. This study therefore investigated two wild antelope species to better understand their reported performance capability. Muscle samples collected post mortem from the vastus lateralis and longissimus lumborum of fallow deer (Dama dama) and springbok (Antidorcas marsupialis) were analysed for myosin heavy chain isoform content, citrate synthase, 3-hydroxyacyl CoA dehydrogenase, phosphofructokinase, lactate dehydrogenase and creatine kinase activities. Cross-sectional areas, fibre type and oxidative capacities of each fibre type were determined in the vastus lateralis only. The predominant fibre type in both muscle groups and species were type IIX (>50%), with springbok having more type IIX fibres than fallow deer (P<0.05). Overall cross-sectional area was not different between the two species. The metabolic pathway analyses showed high glycolytic and oxidative capacities for both species, but springbok had significantly higher CS activities than fallow deer. Large variation and overlap in oxidative capacities existed within and between the fibre types. Some type IIX fibres presented with oxidative capacities similar to those from type I and IIA fibres. The data suggest that springbok and fallow deer are able sprint at >90 and 46 km h−1, respectively, partly from having large type IIX fibre contents and high glycolytic capacities. The high oxidative capacities also suggest that these animals may be able to withstand fatigue for long periods of time. PMID:22899533

Specific characteristics of the aviary housing system affect plumage condition, mortality and production in laying hens.

PubMed

Heerkens, Jasper L T; Delezie, Evelyne; Kempen, Ine; Zoons, Johan; Ampe, Bart; Rodenburg, T Bas; Tuyttens, Frank A M

2015-09-01

Feather pecking and high mortality levels are significant welfare problems in non-cage housing systems for laying hens. The aim of this study was to identify husbandry-related risk factors for feather damage, mortality, and egg laying performance in laying hens housed in the multi-tier non-cage housing systems known as aviaries. Factors tested included type of system flooring, degree of red mite infestation, and access to free-range areas. Information on housing characteristics, management, and performance in Belgian aviaries (N=47 flocks) were obtained from a questionnaire, farm records, and farm visits. Plumage condition and pecking wounds were scored in 50 randomly selected 60-week-old hens per flock. Associations between plumage condition, wounds, performance, mortality, and possible risk factors were investigated using a linear model with a stepwise model selection procedure. Many flocks exhibited a poor plumage condition and a high prevalence of wounds, with considerable variation between flocks. Better plumage condition was found in wire mesh aviaries (P<0.001), in aviaries with no red mite infestation (P=0.004), and in free-range systems (P=0.011) compared to plastic slatted aviaries, in houses with red mite infestations, and those without a free-range area. Furthermore, hens in aviaries with wire mesh flooring had fewer wounds on the back (P=0.006) and vent (P=0.009), reduced mortality (P=0.003), and a better laying performance (P=0.013) as compared to hens in aviaries with plastic slatted flooring. Flocks with better feather cover had lower levels of mortality (P<0.001). Red mite infestations were more common in plastic slatted aviaries (P=0.043). Other risk factors associated with plumage condition were genotype, number of diet changes, and the presence of nest perches. Wire mesh flooring in particular seems to have several health, welfare, and performance benefits in comparison to plastic slats, possibly related to decreased feather pecking, better hygiene, and fewer red mite infestations. This suggests that adjustments to the aviary housing design may further improve laying hen welfare and performance. © 2015 Poultry Science Association Inc.

Effects of rumen-escape starch and coarseness of ingredients in pelleted concentrates on performance and rumen wall characteristics of rosé veal calves.

PubMed

Vestergaard, M; Jarltoft, T C; Kristensen, N B; Børsting, C F

2013-08-01

The objective was to study the effect of rumen-escape starch and coarseness of ingredients in pelleted concentrates on performance, carcass quality and rumen wall characteristics in rosé veal calf production. Two alternative concentrates (Coarse and Slow) were compared with a traditional (Control) concentrate. Control was based on finely ground ingredients, whereas in Coarse, the same ingredients were coarsely ground resulting in a mean particle size before pelleting of 1.5 in Coarse and 0.6 mm in Control. Slow compared with Control and Coarse contained finely ground sorghum and corn instead of barley and wheat which increased the amount of rumen-escape starch to 59 compared with 22 g/kg in Control and Coarse. All concentrates had the same total starch (362 g/kg), NDF (168 g/kg), CP (154 g/kg) and DE (15.5 MJ/kg DM) content and a pellet diameter of 3.5 to 4 mm. Use of an 'indicator of starch digestibility' method gave a value of 98.6% for Control and Coarse and 91.1% for Slow (P < 0.001). A total of 57 Holstein bull calves (n = 19 per treatment) were offered one of the three concentrates ad libitum from weaning (2½ months of age) to slaughter (<10 months of age). Concentrate intake was recorded individually. Barley straw was available ad libitum but intake was not recorded. Average daily gain (1.43 kg/day), concentrate conversion efficiency (3.7 kg DM concentrate/kg gain), LW at slaughter (386 kg), carcass weight (194 kg) and EUROP conformation (3.9) were not affected by type of concentrate (P > 0.05). Papillae length and shape evaluated in atrium ruminis and the cranial part of the ventral rumen sac at slaughter were not affected by type of concentrate (P > 0.05). Rumen wall characteristics showed degrees of plaque formation (i.e., papillary aggregation), hyperaemia and necrotic areas in all treatment groups, but with no general difference between type of concentrate (P > 0.05). Incidence of liver abscesses (LAs, 16%) was not affected by type of concentrate (P > 0.05). There were no differences in performance or rumen wall characteristics between liver-abscessed and non-abscessed calves. The results show a high level of production performance with the three types of pelleted concentrates and indicates that neither the more coarse ingredients nor the additional rumen-escape starch tested, when fed ad libitum, could improve rumen wall characteristics or reduce LAs of rosé veal calves.

Cardiovascular and cortisol reactions to acute psychological stress under conditions of high versus low social evaluative threat: associations with the type D personality construct.

PubMed

Bibbey, Adam; Carroll, Douglas; Ginty, Annie T; Phillips, Anna C

2015-06-01

Social evaluative threat is an important factor in the cardiovascular response to mental stress. This study examined whether Type D personality, characterized by social inhibition and negative affectivity, is associated with an adverse cardiovascular response to a non-social and social evaluative threat. A total of 2300 students were screened for Type D personality, and 130 were selected for a nonsocial stress exposure condition (31 Type D, 30 non-Type D: 52% female) or a condition high in social evaluative threat (35 Type D, 34 non-Type D: 55% female). Systolic (SBP) and diastolic blood pressure (DBP), heart rate (HR), and salivary cortisol were measured. Social evaluative threat resulted in higher cardiovascular responses than the nonsocial challenge (SBP, p = .001, η = 0.092;DBP, p = .006, η = 0.058;HR, p = .006, η = 0.059). The greatest cardiovascular stress reactions were exhibited by Type D participants in the high social evaluation condition; reflected in significant group by condition interactions for SBP (F(1,126) = 7.29, p = .008, η = 0.055), DBP (F(1,126) = 5.23, p = .024, η = 0.040), and HR (F(1,126) = 5.04, p = .027, η = 0.038) reactivity. Only Type Ds in the social condition mounted a positive cortisol response (F(1,33) = 5.07, p = .031, η = 0.133). Type D individuals show different stress reactions depending on the social evaluative nature of the stress exposure. These findings suggest that dysregulation of the stress response in social situations potentially increases cardiovascular disease risk.

Quantum junction solar cells.

PubMed

Tang, Jiang; Liu, Huan; Zhitomirsky, David; Hoogland, Sjoerd; Wang, Xihua; Furukawa, Melissa; Levina, Larissa; Sargent, Edward H

2012-09-12

Colloidal quantum dot solids combine convenient solution-processing with quantum size effect tuning, offering avenues to high-efficiency multijunction cells based on a single materials synthesis and processing platform. The highest-performing colloidal quantum dot rectifying devices reported to date have relied on a junction between a quantum-tuned absorber and a bulk material (e.g., TiO(2)); however, quantum tuning of the absorber then requires complete redesign of the bulk acceptor, compromising the benefits of facile quantum tuning. Here we report rectifying junctions constructed entirely using inherently band-aligned quantum-tuned materials. Realizing these quantum junction diodes relied upon the creation of an n-type quantum dot solid having a clean bandgap. We combine stable, chemically compatible, high-performance n-type and p-type materials to create the first quantum junction solar cells. We present a family of photovoltaic devices having widely tuned bandgaps of 0.6-1.6 eV that excel where conventional quantum-to-bulk devices fail to perform. Devices having optimal single-junction bandgaps exhibit certified AM1.5 solar power conversion efficiencies of 5.4%. Control over doping in quantum solids, and the successful integration of these materials to form stable quantum junctions, offers a powerful new degree of freedom to colloidal quantum dot optoelectronics.

Is coracoclavicular stabilisation alone sufficient for the endoscopic treatment of severe acromioclavicular joint dislocation (Rockwood types III, IV, and V)?

PubMed

Barth, J; Duparc, F; Andrieu, K; Duport, M; Toussaint, B; Bertiaux, S; Clavert, P; Gastaud, O; Brassart, N; Beaudouin, E; De Mourgues, P; Berne, D; Bahurel, J; Najihi, N; Boyer, P; Faivre, B; Meyer, A; Nourissat, G; Poulain, S; Bruchou, F; Ménard, J F

2015-12-01

The primary objective was to evaluate correlations linking anatomical to functional outcomes after endoscopically assisted repair of acute acromioclavicular joint dislocation (ACJD). Combined acromioclavicular and coracoclavicular stabilisation improves radiological outcomes compared to coracoclavicular stabilisation alone. A prospective multicentre study was performed. Clinical outcome measures were pain intensity on a visual analogue scale (VAS), subjective functional impairment (QuickDASH score), and Constant's score. Anatomical outcomes were assessed on standard radiographs (anteroposterior view of the acromioclavicular girdle and bilateral axillary views) obtained preoperatively and postoperatively and on postoperative dynamic radiographs taken as described by Tauber et al. Of 116 patients with acute ACJD included in the study, 48% had type III, 30% type IV, and 22% type V ACJD according to the Rockwood classification. Coracoclavicular stabilisation was achieved using a double endobutton in 93% of patients, and concomitant acromioclavicular stabilisation was performed in 50% of patients. The objective functional outcome was good, with an unweighted Constant's score ≥ 85/100 and a subjective QuickDASH functional disability score ≤ 10 in 75% of patients. The radiographic analysis showed significant improvements from the preoperative to the 1-year postoperative values in the vertical plane (decrease in the coracoclavicular ratio from 214 to 128%, p=10(-6)) and in the horizontal plane (decrease in posterior displacement from 4 to 0mm, p=5×10(-5)). The anatomical outcome correlated significantly with the functional outcome (absolute R value=0.19 and p=0.045). We found no statistically significant differences across the various types of constructs used. Intra-operative control of the acromioclavicular joint did not improve the result. Implantation of a biological graft significantly improved both the anatomical outcome in the vertical plane (p=0.04) and acromioclavicular stabilisation in the horizontal plane (p=0.02). The coracoclavicular ratio on the anteroposterior radiograph was adversely affected by a longer time from injury to surgery (p=0.02) and by a higher body mass index (BMI) (p=0.006). High BMI also had a negative effect on the difference in the distance separating the anterior edge of the acromion from the anterior edge of the clavicle between the injured and uninjured sides, as assessed on the axillary views (p=0.009). This study demonstrates that acute ACJD requires stabilisation in both planes, i.e., at the coracoclavicular junction and at the acromioclavicular joint. Coracoclavicular stabilisation alone is not sufficient, regardless of the type of implant used. Implantation of a biological graft should be considered when the time from injury to surgery is longer than 10days. The weight of the upper limb should be taken into account, with 6weeks of immobilisation to unload the construct in patients who have high BMI values. II, prospective non-randomised comparative study. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Structure and Electric Conduction in Pulsed Laser-Deposited ZnO Thin Films Individually Doped with N, P, or Na

NASA Astrophysics Data System (ADS)

Jiao, D. L.; Zhong, X. C.; Qiu, W. Q.; Zhang, H.; Liu, Z. W.; Zhang, G. Q.

2018-03-01

N-, P-, and Na-doped ZnO films with c-axis orientation were produced by pulsed laser deposition using N2O or O2 as the reaction gas. The effects of deposition temperature and deposition pressure on the lattice structure, morphology, and electric conduction have been investigated. High gas pressure leads to large-sized grains with large grain barriers, which cause a reduced mobility. P acts as an acceptor and the number of compensating defects in the P-doped film is reduced under high O2 pressure. Na also acts as an acceptor, and the effects of high temperature on Na-doped films are encouraging as the solubility of the dopant is high. However, high temperature may cause less incorporation of N and P in the film. In the present work, p-type conduction has not been obtained in N- and P-doped films despite a wide range of processing parameters employed. Na-doped films display an increasing trend towards p-type films at high temperatures and high O2 pressures. These results provide an insight on how these dopants behave in ZnO films and indicate that the careful selection of the deposition conditions is necessary in order to obtain p-type films by pulsed laser deposition.

Realizing p-Type MoS2 with Enhanced Thermoelectric Performance by Embedding VMo2S4 Nanoinclusions.

PubMed

Kong, Shuang; Wu, Tianmin; Zhuang, Wei; Jiang, Peng; Bao, Xinhe

2018-01-18

Two-dimensional transition-metal dichalcogenide semiconductors (TMDCs) such as MoS 2 are attracting increasing interest as thermoelectric materials owing to their abundance, nontoxicity, and promising performance. Recently, we have successfully developed n-type MoS 2 thermoelectric material via oxygen doping. Nevertheless, an efficient thermoelectric module requires both n-type and p-type materials with similar compatibility factors. Here, we present a facile approach to obtain a p-type MoS 2 thermoelectric material with a maximum figure of merit of 0.18 through the introduction of VMo 2 S 4 as a second phase by vanadium doping. VMo 2 S 4 nanoinclusions, confirmed by X-ray powder diffraction (XRD) and transmission electron microscopy (TEM) measurements, not only improve the electrical conductivity by simultaneously increasing the carrier concentration and the mobility but also result in the reduction of lattice thermal conductivity by enhancing the interface phonon scattering. Our studies not only shed new light toward improving thermoelectric performance of TMDCs by a facile elemental doping strategy but also pave the way toward thermoelectric devices based on TMDCs.

Reconfigurable Complementary Logic Circuits with Ambipolar Organic Transistors

PubMed Central

Yoo, Hocheon; Ghittorelli, Matteo; Smits, Edsger C. P.; Gelinck, Gerwin H.; Lee, Han-Koo; Torricelli, Fabrizio; Kim, Jae-Joon

2016-01-01

Ambipolar organic electronics offer great potential for simple and low-cost fabrication of complementary logic circuits on large-area and mechanically flexible substrates. Ambipolar transistors are ideal candidates for the simple and low-cost development of complementary logic circuits since they can operate as n-type and p-type transistors. Nevertheless, the experimental demonstration of ambipolar organic complementary circuits is limited to inverters. The control of the transistor polarity is crucial for proper circuit operation. Novel gating techniques enable to control the transistor polarity but result in dramatically reduced performances. Here we show high-performance non-planar ambipolar organic transistors with electrical control of the polarity and orders of magnitude higher performances with respect to state-of-art split-gate ambipolar transistors. Electrically reconfigurable complementary logic gates based on ambipolar organic transistors are experimentally demonstrated, thus opening up new opportunities for ambipolar organic complementary electronics. PMID:27762321

Reconfigurable Complementary Logic Circuits with Ambipolar Organic Transistors.

PubMed

Yoo, Hocheon; Ghittorelli, Matteo; Smits, Edsger C P; Gelinck, Gerwin H; Lee, Han-Koo; Torricelli, Fabrizio; Kim, Jae-Joon

2016-10-20

Ambipolar organic electronics offer great potential for simple and low-cost fabrication of complementary logic circuits on large-area and mechanically flexible substrates. Ambipolar transistors are ideal candidates for the simple and low-cost development of complementary logic circuits since they can operate as n-type and p-type transistors. Nevertheless, the experimental demonstration of ambipolar organic complementary circuits is limited to inverters. The control of the transistor polarity is crucial for proper circuit operation. Novel gating techniques enable to control the transistor polarity but result in dramatically reduced performances. Here we show high-performance non-planar ambipolar organic transistors with electrical control of the polarity and orders of magnitude higher performances with respect to state-of-art split-gate ambipolar transistors. Electrically reconfigurable complementary logic gates based on ambipolar organic transistors are experimentally demonstrated, thus opening up new opportunities for ambipolar organic complementary electronics.

p-Type Transparent Conducting Oxide/n-Type Semiconductor Heterojunctions for Efficient and Stable Solar Water Oxidation.

PubMed

Chen, Le; Yang, Jinhui; Klaus, Shannon; Lee, Lyman J; Woods-Robinson, Rachel; Ma, Jie; Lum, Yanwei; Cooper, Jason K; Toma, Francesca M; Wang, Lin-Wang; Sharp, Ian D; Bell, Alexis T; Ager, Joel W

2015-08-05

Achieving stable operation of photoanodes used as components of solar water splitting devices is critical to realizing the promise of this renewable energy technology. It is shown that p-type transparent conducting oxides (p-TCOs) can function both as a selective hole contact and corrosion protection layer for photoanodes used in light-driven water oxidation. Using NiCo2O4 as the p-TCO and n-type Si as a prototypical light absorber, a rectifying heterojunction capable of light driven water oxidation was created. By placing the charge separating junction in the Si using a np(+) structure and by incorporating a highly active heterogeneous Ni-Fe oxygen evolution catalyst, efficient light-driven water oxidation can be achieved. In this structure, oxygen evolution under AM1.5G illumination occurs at 0.95 V vs RHE, and the current density at the reversible potential for water oxidation (1.23 V vs RHE) is >25 mA cm(-2). Stable operation was confirmed by observing a constant current density over 72 h and by sensitive measurements of corrosion products in the electrolyte. In situ Raman spectroscopy was employed to investigate structural transformation of NiCo2O4 during electrochemical oxidation. The interface between the light absorber and p-TCO is crucial to produce selective hole conduction to the surface under illumination. For example, annealing to produce more crystalline NiCo2O4 produces only small changes in its hole conductivity, while a thicker SiOx layer is formed at the n-Si/p-NiCo2O4 interface, greatly reducing the PEC performance. The generality of the p-TCO protection approach is demonstrated by multihour, stable, water oxidation with n-InP/p-NiCo2O4 heterojunction photoanodes.

Genetic variation of pfhrp2 in Plasmodium falciparum isolates from Yemen and the performance of HRP2-based malaria rapid diagnostic test.

PubMed

Atroosh, Wahib M; Al-Mekhlafi, Hesham M; Al-Jasari, Adel; Sady, Hany; Al-Delaimy, Ahmed K; Nasr, Nabil A; Dawaki, Salwa; Abdulsalam, Awatif M; Ithoi, Init; Lau, Yee Ling; Fong, Mun Yik; Surin, Johari

2015-07-22

The genetic variation in the Plasmodium falciparum histidine-rich protein 2 (pfhrp2) gene that may compromise the use of pfhrp2-based rapid diagnostic tests (RDTs) for the diagnosis of malaria was assessed in P. falciparum isolates from Yemen. This study was conducted in Hodeidah and Al-Mahwit governorates, Yemen. A total of 622 individuals with fever were examined for malaria by CareStart malaria HRP2-RDT and Giemsa-stained thin and thick blood films. The Pfhrp2 gene was amplified and sequenced from 180 isolates, and subjected to amino acid repeat types analysis. A total of 188 (30.2%) participants were found positive for P. falciparum by the RDT. Overall, 12 different amino acid repeat types were identified in Yemeni isolates. Six repeat types were detected in all the isolates (100%) namely types 1, 2, 6, 7, 10 and 12 while types 9 and 11 were not detected in any of the isolates. Moreover, the sensitivity and specificity of the used PfHRP2-based RDTs were high (90.5% and 96.1%, respectively). The present study provides data on the genetic variation within the pfhrp2 gene, and its potential impact on the PfHRP2-based RDTs commonly used in Yemen. CareStart Malaria HRP2-based RDT showed high sensitivity and specificity in endemic areas of Yemen.

HOGA1 Gene Mutations of Primary Hyperoxaluria Type 3 in Tunisian Patients.

PubMed

M'dimegh, Saoussen; Aquaviva-Bourdain, Cécile; Omezzine, Asma; Souche, Geneviéve; M'barek, Ibtihel; Abidi, Kamel; Gargah, Tahar; Abroug, Saoussen; Bouslama, Ali

2017-05-01

Primary hyperoxaluria type 3 (PH3) is due to mutations in the recently identified 4-hydroxy-2-oxoglutarate aldolase (HOGA1) gene. PH3 might be the least severe form with a milder phenotype with good preservation of kidney function in most patients. The aim of this study was to report three PH3 cases carrying mutations in HOGA1. Genetic analysis of HOGA1 was performed in patients with a high clinical suspicion of PH after sequencing of AGXT and GRHPR genes, which was negative. Also, a complete AGXT/GRHPR MLPA was performed in these patients in order to detect large deletions/insertions. Two different HOGA1 gene mutations were identified: the p.Pro190Leu in a homozygous state and the p.Gly287Val in two patients in homozygous and heterozygous carriers. The median age at onset of clinical symptoms was 3.93 years. Most of the patients had a positive family history for recurrent urolithiasis. The p.Pro190Leu mutation was reported with impaired renal function at follow-up; however, the p.Gly287Val was presented with normal renal function. All patients were presented with urolithiasis, but only one had a nephrocalcinosis. This study expanded the number of PH3 patients from 63 to 66 cases. The p.Pro190Leu and the p.Gly287Val mutations found in this study can provide a first-line investigation in Tunisian PH1 patients. © 2016 Wiley Periodicals, Inc.

High resolution and high sensitivity methods for oligosaccharide mapping and characterization by normal phase high performance liquid chromatography following derivatization with highly fluorescent anthranilic acid.

PubMed

Anumula, K R; Dhume, S T

1998-07-01

Facile labeling of oligosaccharides (acidic and neutral) in a nonselective manner was achieved with highly fluorescent anthranilic acid (AA, 2-aminobenzoic acid) (more than twice the intensity of 2-aminobenzamide, AB) for specific detection at very high sensitivity. Quantitative labeling in acetate-borate buffered methanol (approximately pH 5.0) at 80 degreesC for 60 min resulted in negligible or no desialylation of the oligosaccharides. A high resolution high performance liquid chromatographic method was developed for quantitative oligosaccharide mapping on a polymeric-NH2bonded (Astec) column operating under normal phase and anion exchange (NP-HPAEC) conditions. For isolation of oligosaccharides from the map by simple evaporation, the chromatographic conditions developed use volatile acetic acid-triethylamine buffer (approximately pH 4.0) systems. The mapping and characterization technology was developed using well characterized standard glycoproteins. The fluorescent oligosaccharide maps were similar to the maps obtained by the high pH anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD), except that the fluorescent maps contained more defined peaks. In the map, the oligosaccharides separated into groups based on charge, size, linkage, and overall structure in a manner similar to HPAEC-PAD with contribution of -COOH function from the label, anthranilic acid. However, selectivity of the column for sialic acid linkages was different. A second dimension normal phase HPLC (NP-HPLC) method was developed on an amide column (TSK Gel amide-80) for separation of the AA labeled neutral complex type and isomeric structures of high mannose type oligosaccharides. The oligosaccharides labeled with AA are compatible with biochemical and biophysical techniques, and use of matrix assisted laser desorption mass spectrometry for rapid determination of oligosaccharide mass map of glycoproteins is demonstrated. High resolution of NP-HPAEC and NP-HPLC methods combined with mass spectrometry (MALDI-TOF) can provide an effective technology for analyzing a wide repertoire of oligosaccharide structures and for determining the action of both transferases and glycosidases.

29 CFR 1926.14 - Federal contract for “mixed” types of performance.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 8 2011-07-01 2011-07-01 false Federal contract for âmixedâ types of performance. 1926.14... Interpretations § 1926.14 Federal contract for “mixed” types of performance. (a) It is the intent of the Congress... construction. See, for example, H. Report No. 91-241, 91st Cong., first session, p. 1 (1969). Thus, it is clear...

29 CFR 1926.14 - Federal contract for “mixed” types of performance.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 8 2010-07-01 2010-07-01 false Federal contract for âmixedâ types of performance. 1926.14... Interpretations § 1926.14 Federal contract for “mixed” types of performance. (a) It is the intent of the Congress... construction. See, for example, H. Report No. 91-241, 91st Cong., first session, p. 1 (1969). Thus, it is clear...

Design and clinical pilot testing of the model-based dynamic insulin sensitivity and secretion test (DISST).

PubMed

Lotz, Thomas F; Chase, J Geoffrey; McAuley, Kirsten A; Shaw, Geoffrey M; Docherty, Paul D; Berkeley, Juliet E; Williams, Sheila M; Hann, Christopher E; Mann, Jim I

2010-11-01

Insulin resistance is a significant risk factor in the pathogenesis of type 2 diabetes. This article presents pilot study results of the dynamic insulin sensitivity and secretion test (DISST), a high-resolution, low-intensity test to diagnose insulin sensitivity (IS) and characterize pancreatic insulin secretion in response to a (small) glucose challenge. This pilot study examines the effect of glucose and insulin dose on the DISST, and tests its repeatability. DISST tests were performed on 16 subjects randomly allocated to low (5 g glucose, 0.5 U insulin), medium (10 g glucose, 1 U insulin) and high dose (20 g glucose, 2 U insulin) protocols. Two or three tests were performed on each subject a few days apart. Average variability in IS between low and medium dose was 10.3% (p=.50) and between medium and high dose 6.0% (p=.87). Geometric mean variability between tests was 6.0% (multiplicative standard deviation (MSD) 4.9%). Geometric mean variability in first phase endogenous insulin response was 6.8% (MSD 2.2%). Results were most consistent in subjects with low IS. These findings suggest that DISST may be an easily performed dynamic test to quantify IS with high resolution, especially among those with reduced IS. © 2010 Diabetes Technology Society.

Different regional organisational models and the quality of health care: the case of coronary artery bypass graft surgery.

PubMed

Nobilio, Lucia; Ugolini, Cristina

2003-01-01

The Italian regions of Emilia-Romagna and Lombardy within the Italian National Health Service provide an opportunity to see if two different approaches to the organisation of care--one more hierarchical and planned, the other more competitive and market-like--influence its quality through examining the relationship between the number of coronary artery bypass grafts (CABGs) and the rate of in-hospital mortality using administrative data for the period 1996-1998. Descriptive statistics and logistic regression models were used. The volume-outcome relation was statistically significant in both regions (odds ratio 0.71, P < 0.0001). Although CABG performance in Emilia-Romagna was slightly poorer than in Lombardy (OR 1.22, P < 0.05), the potential advantage in terms of the reduced risk of death for patients treated at high-volume versus low-volume hospitals was significantly greater. In Emilia-Romagna, the average performance advantage of high-volume units was more substantial in the case of private accredited hospitals than public hospitals (OR = 0.50, P < 0.0001 versus OR = 0.64, P < 0.0001). In Lombardy, the performance advantage of concentrating CABG procedures was greater in private research hospitals (OR = 0.67, P < 0.0001), whereas results were not statistically significant for the other types of hospital, indicating a good level of performance in both public and private hospitals even at low volumes. This also partially explained the lower mortality rate observed in that region. The degree of hierarchical regionalisation versus market-like arrangements characterising the two systems produced contrasting effects in terms of the quality of CABG surgery. Lombardy's more competitive environment appeared to achieve better performance in terms of a slightly lower probability of adverse outcomes, in a system with no formal assessment of population need and very high per capita revascularisation rates. To improve performance in the more hierarchical system adopted in Emilia-Romagna would require considerable effort to increase CABG surgery in low-volume cardiac units, and to sharpen performance incentives.

Evaluation of robotic endovascular catheters for arch vessel cannulation.

PubMed

Riga, Celia V; Bicknell, Colin D; Hamady, Mohamad S; Cheshire, Nicholas J W

2011-09-01

Conventional catheter instability and embolization risk limits the adoption of endovascular therapy in patients with challenging arch anatomy. This study investigated whether arch vessel cannulation can be enhanced by a remotely steerable robotic catheter system. Seventeen clinicians with varying endovascular experience cannulated all arch vessels within two computed tomography-reconstructed pulsatile flow phantoms (bovine type I and type III aortic arches), under fluoroscopic guidance, using conventional and robotic techniques. Quantitative (catheterization times, catheter tip movements, vessel wall hits, catheter deflection) and qualitative metrics (Imperial College Complex Endovascular Cannulation Scoring Tool [IC3ST]) performance scores were compared. Robotic catheterization techniques resulted in a significant reduction in median carotid artery cannulation times and the median number of catheter tip movements for all vessels. Vessel wall contact with the aortic arch wall was reduced to a median of zero with robotic catheters. During stiff guidewire exchanges, robotic catheters maintained stability with zero deflection, independent of the distance the catheter was introduced into the carotid vessels. Overall IC3ST performance scores (interquartile range) were significantly improved using the robotic system: Type I arch score was 26/35 (20-30.8) vs 33/35 (31-34; P = .001), and type III arch score was 20.5/35 (16.5-28.5) vs 26.5/35 (23.5-28.8; P = .001). Low- and medium-volume interventionalists demonstrated an improvement in performance with robotic cannulation techniques. The high-volume intervention group did not show statistically significant improvement, but cannulation times, movements, and vessel wall hits were significantly reduced. Robotic technology has the potential to reduce the time, risk of embolization and catheter dislodgement, radiation exposure, and the manual skill required for carotid and arch vessel cannulation, while improving overall performance scores. Copyright © 2011 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

Evaluation of litter type and dietary coarse ground corn inclusion on broiler live performance, gastrointestinal tract development, and litter characteristics.

PubMed

Xu, Y; Stark, C R; Ferket, P R; Williams, C M; Nusairat, B; Brake, J

2015-03-01

Two 49 d floor pen studies were conducted to evaluate the effects of litter type and dietary coarse ground corn (CC) inclusion on broiler live performance, gastrointestinal tract (GIT) development, and litter characteristics. Experiment 1 was a 2×2 factorial arrangement of 2 genders (male or female) and 2 CC levels (0 or 50%). From 15 to 35 d, the addition of CC decreased feed intake (P<0.01) and BW gain (P<0.05) of males but not females. The inclusion of CC decreased feed intake (P<0.01) and BW gain (P<0.01) from 0 to 49 d but improved adjusted feed conversion ratio (AdjFCR) from 35 to 49 d (P<0.05). Male broilers exhibited better live performance than females during the study as evidenced by greater feed intake (P<0.01) and BW gain (P<0.01), and improved FCR (P<0.01), but with increased mortality (P<0.05). The inclusion of CC increased relative gizzard weight (P<0.01) and decreased relative proventriculus weight (P<0.01) at 49 d. Experiment 2 was a 2×2 factorial arrangement of 2 CC levels (0 or 50%) and 2 litter types (ground old litter or new wood shavings litter). The inclusion of CC decreased feed intake throughout the experiment without affecting final BW when only males were used and improved FCR after 25 d (P<0.01). New litter improved FCR from 1 to 14 d (P<0.01). At 49 d, the birds fed the CC diet had reduced excreta nitrogen (P<0.05) and litter moisture (P<0.05). In conclusion, 50% CC inclusion initially produced negative effects on live performance that became positive as BW increased. The effects of CC became evident at an earlier age for males. New litter had only a marginal benefit on broiler live performance. © 2015 Poultry Science Association Inc.

Determination and comparison of γ-aminobutyric acid (GABA) content in pu-erh and other types of Chinese tea.

PubMed

Zhao, Ming; Ma, Yan; Wei, Zhen-zhen; Yuan, Wen-xia; Li, Ya-li; Zhang, Chun-hua; Xue, Xiao-ting; Zhou, Hong-jie

2011-04-27

Two previous studies have reported that pu-erh tea contains a high level of γ-aminobutyric acid (GABA), which is the major inhibitory neurotransmitter in the central nervous system and has several physiological functions. However, two other researchers have demonstrated that the GABA content of several pu-erh teas was low. Due to the high value and health benefits of GABA, analysis of mass-produced pu-erh tea is necessary to determine whether it is actually enriched with GABA. A high-performance liquid chromatography (HPLC) method was developed for the determination of GABA in tea, the results of which were verified by amino acid analysis using an Amino Acid Analyzer (AAA). A total of 114 samples of various types of Chinese tea, including 62 pu-erh teas, 13 green teas, 8 oolong teas, 8 black teas, 3 white teas, 4 GABA teas, and 16 process samples from two industrial fermentations of pu-erh tea (including the raw material and the first to seventh turnings), were analyzed using HPLC. Statistical analysis demonstrated that the GABA content in pu-erh tea was significantly lower than that in other types of tea (p < 0.05) and that the GABA content decreased during industrial fermentation of pu-erh tea (p < 0.05). This mass analysis and comparison suggested GABA was not a major bioactive constituent and resolved the disagreement GABA content in pu-erh tea. In addition, the GABA content in white tea was found to be significantly higher than that in the other types of tea (p < 0.05), leading to the possibility of producing GABA-enriched white tea.

Description of IMP-31, a novel metallo-β-lactamase found in an ST235 Pseudomonas aeruginosa strain in Western Germany.

PubMed

Pfennigwerth, Niels; Geis, Gabriele; Gatermann, Sören G; Kaase, Martin

2015-07-01

The objective of this study was to characterize a novel IMP-type metallo-β-lactamase (MBL) found in an MDR clinical isolate of Pseudomonas aeruginosa. The P. aeruginosa isolate NRZ-00156 was recovered from an inguinal swab from a patient hospitalized in Western Germany and showed high MICs of carbapenems. MBL production was analysed by Etest for MBLs, an EDTA combined disc test and an EDTA bioassay. Typing of the isolate was performed by MLST. Genetic characterization of the new blaIMP gene was performed by sequencing the PCR products. A phylogenetic tree was constructed. The novel blaIMP gene was expressed in Escherichia coli TOP10 and the enzyme was subjected to biochemical characterization. The P. aeruginosa isolate NRZ-00156 expressed the ST235 allelic profile and was resistant to all the β-lactams tested except aztreonam. The isolate was positive for MBL production and harboured a new IMP allele, blaIMP-31, located on a disrupted class I integron [also carrying the blaOXA-35, aac(6')-Ib, aac(3)-Ic and aphA15 genes]. Its closest relative was IMP-35, with 96.7% amino acid identity. Expression of blaIMP-31 demonstrated that E. coli TOP10 producing IMP-31 had elevated resistance to all the β-lactams tested except aztreonam. Kinetic data were obtained for both IMP-31 and IMP-1. In comparison with IMP-1, IMP-31 showed weaker hydrolytic activity against all the β-lactams tested, which resulted from lower kcat values. The characterization of the new IMP-type gene blaIMP-31 from an ST235 P. aeruginosa isolate indicates an ongoing spread of highly divergent IMP-type carbapenemases in clinical P. aeruginosa strains and highlights the continuous need for the prevention of nosocomial infections caused by MDR Gram-negative bacteria. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

High-performance thermoelectric mineral Cu12-xNixSb4S13 tetrahedrite

NASA Astrophysics Data System (ADS)

Suekuni, Koichiro; Tsuruta, Kojiro; Kunii, Masaru; Nishiate, Hirotaka; Nishibori, Eiji; Maki, Sachiko; Ohta, Michihiro; Yamamoto, Atsushi; Koyano, Mikio

2013-01-01

X-ray structural analysis and high-temperature thermoelectric properties measurements are performed on polycrystalline samples of artificial mineral Cu12-xNixSb4S13 tetrahedrite. Analysis of the atomic displacement parameter manifests low-energy vibration of Cu(2) out of CuS3 triangle plane. The vibration results in low lattice thermal conductivity of less than 0.5 W K-1 m-1. By tuning of the Ni composition x and decrease of electronic thermal conductivity, dimensionless thermoelectric figure of merit for x = 1.5 achieves 0.7 at 665 K, which is a considerably high value among p-type Pb-free sulfides. Because the tetrahedrite is an environmentally friendly material, it constitutes a good thermoelectric material for use in support of a sustainable society.

First principles Study on Transparent High-Tc Superconductivity in hole-doped Delafossite CuAlO2

NASA Astrophysics Data System (ADS)

Nakanishi, Akitaka; Katayama-Yoshida, Hiroshi

2012-02-01

The CuAlO2 is the transparent p-type conductor without any intentional doping. Transparent superdoncutivity and high thermoelectric power are suggested in p-type CuAlO2 [1]. Katayama-Yoshida et al. proposed that it may cause a strong electron-phonon interaction and a superconductivity. But, the calculation of superconducting critical temperature Tc is not performed. We performed the first principles calculation about the Tc of hole-doped CuAlO2 by shifting the Fermi level rigidly. In lightly hole-doped CuAlO2, the Fermi level is located at Cu and O anti-bonding band. The electrons of this band strongly interact with the A1L1 phonon mode because the direction of O-Cu-O dumbbell is parallel to the oscillation direction of the A1L1 phonon mode. As a result, Tc of lightly hole-doped CuAlO2 is about 50 K. We also discuss the materials design to enhance the Tc based on the charge-excitation-induced negative effective U system.[4pt] [1] H. Katayama-Yoshida, T. Koyanagi, H. Funashima, H. Harima, A. Yanase: Solid State Communication 126 (2003) 135. [0pt] [2] A. Nakanishi and H. Katayama-Yoshida: Solid State Communication, in printing. (arXiv:1107.2477v3

Recombinant glycoprotein G analog for determination of specific immunoglobulins to herpes simplex virus type 2 by ELISA.

PubMed

Korshun, Ludmila; Vudmaska, Mariya; Moysa, Larissa; Kovtonjuk, Galina; Mikhalap, Svetlana; Ganova, Larissa; Spivak, Nikolay

2013-12-01

In order to the detection of type-specific IgG to herpes simplex virus type 2 (HSV-2) in human serum or plasma the recombinant analog of HSV-2 glycoprotein G (gG2) was created. To construct an expression vector the DNA fragment with a sequence identical to immunodominant regions of HSV-2 gG2 was cloned into modified vector pET28a containing of the glutation-S-transferase sequence (pET28-GST). Escherichia coli BL21 (DE3) were transformed with the recombinant plasmid. The target protein was expressed mainly in soluble form. Chromatographic purification of soluble GST-gG2 protein was performed taking into account the features of its primary structure that are 6His-tag and GST-tag. To determine the affinity constant of the specific IgG to GST-gG2 we used the method proposed by Friguet et al. (1985). The affinity constants were within the range of 10(7)-10(8)M(-1) proving their high-affinity. The purified recombinant HSV-2 antigen was used to design a diagnostic ELISA kit, which was evaluated with referent controls and standard panels of sera containing and/or not containing anti-HSV-2 IgG. Comparative evaluation of this kit and the commercially available "HSV-Type 2 IgG-ELISA" (NovaTec, Dietzenbach, Germany) kit was performed. There was no significant difference (P>0.05). It allows to use developed ELISA kit for clinical diagnosis of HSV-2 infection. Copyright © 2013 Elsevier B.V. All rights reserved.

Correlation of High-Resolution Manometric Findings with Symptoms of Dysphagia and Endoscopic Features in Adults with Eosinophilic Esophagitis.

PubMed

von Arnim, Ulrike; Kandulski, Arne; Weigt, Jochen; Malfertheiner, Peter

2017-01-01

Eosinophilic esophagitis (EoE) presents with dysphagia, but data about motility patterns using high-resolution manometry (HRM) are rare. We aimed at evaluating esophageal motility patterns in EoE and their correlation to endoscopic and dysphagia scores. Twenty-six EoE patients and 23 controls were included after 4 weeks of treatment with proton pump inhibitors. Dysphagia and endoscopic scores were evaluated before performing HRM. EoE patients were classified to have fibrostenotic (FS) or inflammatory (IF) type. HRM analysis was performed according to the Chicago classification (CC) system. According to the CC, the HRM findings in EoE and controls were normal in 11 (42%) and 20 (88.5%), p < 0.0001. Weak and failed peristaltic integrity was only seen in EoE patients (failed 1/2.7%, weak 7/26.9%, p = 0.004). Of the EoE patients, 17 had IF and 9 presented with FS type. HRM parameters showed no differences according to the EoE subtype. The endoscopic score in the FS subtype was significantly higher than in EoE with IF subtype (5.33 vs. 3.58, p = 0.001). No significant difference was seen in dysphagia scores in EoE subtypes. HRM findings in EoE are often diagnostic, but they are non-specific and do not correlate with the severity of dysphagia or endoscopic appearance. The clinical impact of HRM in EoE needs further evaluation. © 2017 S. Karger AG, Basel.

Effects of Statin Treatment on Inflammation and Cardiac Function in Heart Failure: An Adjusted Indirect Comparison Meta-Analysis of Randomized Trials.

PubMed

Bonsu, Kwadwo Osei; Reidpath, Daniel Diamond; Kadirvelu, Amudha

2015-12-01

Statins are known to prevent heart failure (HF). However, it is unclear whether statins as class or type (lipophilic or hydrophilic) improve outcomes of established HF. The current meta-analysis was performed to compare the treatment effects of lipophilic and hydrophilic statins on inflammation and cardiac function in HF. Outcomes were indicators of cardiac function [changes in left ventricular ejection fraction (LVEF) and B-type natriuretic peptide (BNP)] and inflammation [changes in highly sensitive C-reactive protein (hsCRP) and interluekin-6 (IL-6)]. We conducted a search of PubMed, EMBASE, and the Cochrane databases until December 31, 2014 for randomized control trials (RCTs) of statin versus placebo in patients with HF. RCTs with their respective extracted information were dichotomized into statin type evaluated and analyzed separately. Outcomes were pooled with random effect approach, producing standardized mean differences (SMD) for each statin type. Using these pooled estimates, we performed adjusted indirect comparisons for each outcome. Data from 6214 patients from 19 trials were analyzed. Lipophilic statin was superior to hydrophilic statin treatment regarding follow-up LVEF (SMD, 4.54; 95% CI, 4.16-4.91; P < 0.001), BNP (SMD, -1.60; 95% CI, -2.56 to -0.65; P < 0.001), hsCRP (SMD, -1.13; 95% CI, -1.54 to -0.72; P < 0.001), and IL-6 (SMD, -3.75; 95% CI, -4.77 to -0.72; P < 0.001) in HF. Lipophilic statin produces greater treatment effects on cardiac function and inflammation compared with hydrophilic statin in patients with HF. Until data from adequately powered head-to-head trial of the statin types are available, our meta-analysis brings clinicians and researchers a step closer to the quest on which statin--lipophilic or hydrophilic--is associated with better outcomes in HF. © 2015 John Wiley & Sons Ltd.

Chemical factors influencing colloid-facilitated transport of contaminants in porous media

USGS Publications Warehouse

Roy, Sujoy B.; Dzombak, David A.

1997-01-01

The effects of colloids on the transport of two strongly sorbing solutesa hydrophobic organic compound, phenanthrene, and a metal ion, Ni2+were studied in sand-packed laboratory columns under different pH and ionic strength conditions. Two types of column experiments were performed as follows:  (i) sorption/mobilization experiments where the contaminant was first sorbed in the column under conditions where no colloids were released and mobilized under conditions where colloids were released as a result of ionic strength reduction in the influent; and (ii) transport experiments where the contaminant, dissolved or sorbed on colloids, was injected into columns packed with a strongly sorbing porous medium. In the first type of experiment, contaminant mobilization was significant only when all releasable colloids were flushed from the column. In all other cases, although high colloid particle concentrations were encountered, there was no marked effect on total contaminant concentrations. In the second type of experiment, colloid deposition efficiencies were shown to control the enhancement of transport. The deposition efficiency was a function of the pH (for a high organic content sand) and of the contaminant concentration (for a charged species such as Ni2+).

Giant Dirac point shift of graphene phototransistors by doped silicon substrate current

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shimatani, Masaaki; Ogawa, Shinpei, E-mail: Ogawa.Shimpei@eb.MitsubishiElectric.co.jp; Fujisawa, Daisuke

2016-03-15

Graphene is a promising new material for photodetectors due to its excellent optical properties and high-speed response. However, graphene-based phototransistors have low responsivity due to the weak light absorption of graphene. We have observed a giant Dirac point shift upon white light illumination in graphene-based phototransistors with n-doped Si substrates, but not those with p-doped substrates. The source-drain current and substrate current were investigated with and without illumination for both p-type and n-type Si substrates. The decay time of the drain-source current indicates that the Si substrate, SiO{sub 2} layer, and metal electrode comprise a metal-oxide-semiconductor (MOS) capacitor due tomore » the presence of defects at the interface between the Si substrate and SiO{sub 2} layer. The difference in the diffusion time of the intrinsic major carriers (electrons) and the photogenerated electron-hole pairs to the depletion layer delays the application of the gate voltage to the graphene channel. Therefore, the giant Dirac point shift is attributed to the n-type Si substrate current. This phenomenon can be exploited to realize high-performance graphene-based phototransistors.« less

Evaluation of Double-Disk Potentiation and Disk Potentiation Tests Using Dipicolinic Acid for Detection of Metallo-β-Lactamase-Producing Pseudomonas spp. and Acinetobacter spp.

PubMed Central

Yong, Dongeun; Lee, Yangsoon; Jeong, Seok Hoon; Lee, Kyungwon

2012-01-01

Accurate detection of metallo-β-lactamase (MBL)-producing Pseudomonas spp. and Acinetobacter spp. became very important with the increasing prevalence of carbapenem-nonsusceptible clinical isolates. The performance of phenotypic MBL detection methods may depend on the types of MBL and the characteristics of the isolates. A high false-positive rate is a problem with EDTA-based MBL detection methods. We evaluated the performance of double-disk potentiation tests (DDPTs) and disk potentiation tests (DPTs) with dipicolinic acid (DPA) using 44 isolates of Pseudomonas spp. and Acinetobacter spp. producing IMP-1-like, VIM-2-like, and SIM-1 type MBLs. Also, we characterized P. aeruginosa isolates with positive imipenem (IPM)-DPA DDPT, but negative meropenem (MEM)-DPA DDPT, and determined possibility of improving a DDPT by using MacConkey agar. Among five different DDPT methods, the IPM-DPA 250-μg method showed the highest sensitivity (97.7%) and specificity (100%). Among four DPT tests, the highest sensitivity (100%) was shown by the IPM-EDTA 1,900-μg disk method, but the specificity was very low (11.4%). Five of six P. aeruginosa isolates with false-negative DDPTs with MEM-DPA 250-μg disks carried blaIMP-6, and the high level resistance to MEM (MIC ≥ 512 μg/ml) was reduced by the presence of phenylalanine arginine β-naphtylamide. Improvement of DDPTs was observed when MacConkey agar was used instead of Mueller-Hinton agar. In conclusion, DPA is a better MBL inhibitor than EDTA for detection of Pseudomonas spp. and Acinetobacter spp. with IMP-1-like, VIM-2-like, and SIM-1-type MBLs. In DPA DDPTs, IPM disks perform better than MEM disks when the isolates are highly resistant to MEM due to the overexpression of efflux pumps. PMID:22837321

Fermentation of Acid-pretreated Corn Stover to Ethanol Without Detoxification Using Pichia stipitis

NASA Astrophysics Data System (ADS)

Agbogbo, Frank K.; Haagensen, Frank D.; Milam, David; Wenger, Kevin S.

In this work, the effect of adaptation on P. stipitis fermentation using acidpretreated corn stover hydrolyzates without detoxification was examined. Two different types of adaptation were employed, liquid hydrolyzate and solid state agar adaptation. Fermentation of 12.5% total solids undetoxified acid-pretreated corn stover was performed in shake flasks at different rotation speeds. At low rotation speed (100 rpm), both liquid hydrolyzate and solid agar adaptation highly improved the sugar consumption rate as well as ethanol production rate compared to the wild-type strains. The fermentation rate was higher for solid agar-adapted strains compared to liquid hydrolyzate-adapted strains. At a higher rotation speed (150 rpm), there was a faster sugar consumption and ethanol production for both the liquid-adapted and the wild-type strains. However, improvements in the fermentation rate between the liquid-adapted and wild strains were less pronounced at the high rotation speed.

GlycA, a marker of acute phase glycoproteins, and the risk of incident type 2 diabetes mellitus: PREVEND study.

PubMed

Connelly, Margery A; Gruppen, Eke G; Wolak-Dinsmore, Justyna; Matyus, Steven P; Riphagen, Ineke J; Shalaurova, Irina; Bakker, Stephan J L; Otvos, James D; Dullaart, Robin P F

2016-01-15

GlycA is a recently developed glycoprotein biomarker of systemic inflammation that may be predictive of incident type 2 diabetes mellitus (T2DM). Analytical performance of the GlycA test, measured on the Vantera® Clinical Analyzer, was evaluated. To test its prospective association with T2DM, GlycA was measured in 4524 individuals from the PREVEND study and a survival analysis was performed with a mean follow-up period of 7.3y. Imprecision for the GlycA test ranged from 1.3-2.3% and linearity was established between 150 and 1588μmol/l. During the follow-up period, 220 new T2DM cases were ascertained. In analyses adjusted for relevant covariates, GlycA was associated with incident T2DM; hazard ratio (HR) for the highest vs. lowest quartile 1.77 [95% Confidence Interval (CI): 1.10-2.86, P=0.01], whereas the association of high sensitivity C-reactive protein (hsCRP) with T2DM was not significant. GlycA remained associated with incident T2DM after additional adjustment for hsCRP; HR 1.71 [1.00-2.92, P=0.04]. A multivariable adjusted analysis of dichotomized subgroups showed that the hazard for incident T2DM was highest in the subgroup with high GlycA and low hsCRP (P=0.03). The performance characteristics of the GlycA test reveal that it is suitable for clinical applications, including assessment of the risk of future T2DM. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

An Analysis of High School Students' Performance on Five Integrated Science Process Skills

NASA Astrophysics Data System (ADS)

Beaumont-Walters, Yvonne; Soyibo, Kola

2001-02-01

This study determined Jamaican high school students' level of performance on five integrated science process skills and if there were statistically significant differences in their performance linked to their gender, grade level, school location, school type, student type and socio-economic background (SEB). The 305 subjects comprised 133 males, 172 females, 146 ninth graders, 159 10th graders, 150 traditional and 155 comprehensive high school students, 164 students from the Reform of Secondary Education (ROSE) project and 141 non-ROSE students, 166 urban and 139 rural students and 110 students from a high SEB and 195 from a low SEB. Data were collected with the authors' constructed integrated science process skills test the results indicated that the subjects' mean score was low and unsatisfactory; their performance in decreasing order was: interpreting data, recording data, generalising, formulating hypotheses and identifying variables; there were statistically significant differences in their performance based on their grade level, school type, student type, and SEB in favour of the 10th graders, traditional high school students, ROSE students and students from a high SEB. There was a positive, statistically significant and fairly strong relationship between their performance and school type, but weak relationships among their student type, grade level and SEB and performance.

Gene replacement in Penicillium roqueforti.

PubMed

Goarin, Anne; Silar, Philippe; Malagnac, Fabienne

2015-05-01

Most cheese-making filamentous fungi lack suitable molecular tools to improve their biotechnology potential. Penicillium roqueforti, a species of high industrial importance, would benefit from functional data yielded by molecular genetic approaches. This work provides the first example of gene replacement by homologous recombination in P. roqueforti, demonstrating that knockout experiments can be performed in this fungus. To do so, we improved the existing transformation method to integrate transgenes into P. roqueforti genome. In the meantime, we cloned the PrNiaD gene, which encodes a NADPH-dependent nitrate reductase that reduces nitrate to nitrite. Then, we performed a deletion of the PrNiaD gene from P. roqueforti strain AGO. The ΔPrNiaD mutant strain is more resistant to chlorate-containing medium than the wild-type strain, but did not grow on nitrate-containing medium. Because genomic data are now available, we believe that generating selective deletions of candidate genes will be a key step to open the way for a comprehensive exploration of gene function in P. roqueforti.

I-V curve hysteresis induced by gate-free charging of GaAs nanowires' surface oxide

NASA Astrophysics Data System (ADS)

Alekseev, P. A.; Geydt, P.; Dunaevskiy, M. S.; Lähderanta, E.; Haggrén, T.; Kakko, J.-P.; Lipsanen, H.

2017-09-01

The control of nanowire-based device performance requires knowledge about the transport of charge carriers and its limiting factors. We present the experimental and modeled results of a study of electrical properties of GaAs nanowires (NWs), considering their native oxide cover. Measurements of individual vertical NWs were performed by conductive atomic force microscopy (C-AFM). Experimental C-AFM observations with numerical simulations revealed the complex resistive behavior of NWs. A hysteresis of current-voltage characteristics of the p-doped NWs as-grown on substrates with different types of doping was registered. The emergence of hysteresis was explained by the trapping of majority carriers in the surface oxide layer near the reverse-biased barriers under the source-drain current. It was found that the accumulation of charge increases the current for highly doped p+-NWs on n+-substrates, while for moderately doped p-NWs on p+-substrates, charge accumulation decreases the current due to blocking of the conductive channel of NWs.

STING-Licensed Macrophages Prime Type I IFN Production by Plasmacytoid Dendritic Cells in the Bone Marrow during Severe Plasmodium yoelii Malaria

PubMed Central

Fooksman, David; Moore, Jamie M.; Saidi, Alex; Feintuch, Catherine M.; Reizis, Boris; Chorro, Laurent; Daily, Johanna; Lauvau, Grégoire

2016-01-01

Malaria remains a global health burden causing significant morbidity, yet the mechanisms underlying disease outcomes and protection are poorly understood. Herein, we analyzed the peripheral blood of a unique cohort of Malawian children with severe malaria, and performed a comprehensive overview of blood leukocytes and inflammatory mediators present in these patients. We reveal robust immune cell activation, notably of CD14+ inflammatory monocytes, NK cells and plasmacytoid dendritic cells (pDCs) that is associated with very high inflammation. Using the Plasmodium yoelii 17X YM surrogate mouse model of lethal malaria, we report a comparable pattern of immune cell activation and inflammation and found that type I IFN represents a key checkpoint for disease outcomes. Compared to wild type mice, mice lacking the type I interferon (IFN) receptor exhibited a significant decrease in immune cell activation and inflammatory response, ultimately surviving the infection. We demonstrate that pDCs were the major producers of systemic type I IFN in the bone marrow and the blood of infected mice, via TLR7/MyD88-mediated recognition of Plasmodium parasites. This robust type I IFN production required priming of pDCs by CD169+ macrophages undergoing activation upon STING-mediated sensing of parasites in the bone marrow. pDCs and macrophages displayed prolonged interactions in this compartment in infected mice as visualized by intravital microscopy. Altogether our findings describe a novel mechanism of pDC activation in vivo and precise stepwise cell/cell interactions taking place during severe malaria that contribute to immune cell activation and inflammation, and subsequent disease outcomes. PMID:27792766

pFlogger: The Parallel Fortran Logging Utility

NASA Technical Reports Server (NTRS)

Clune, Tom; Cruz, Carlos A.

2017-01-01

In the context of high performance computing (HPC), software investments in support of text-based diagnostics, which monitor a running application, are typically limited compared to those for other types of IO. Examples of such diagnostics include reiteration of configuration parameters, progress indicators, simple metrics (e.g., mass conservation, convergence of solvers, etc.), and timers. To some degree, this difference in priority is justifiable as other forms of output are the primary products of a scientific model and, due to their large data volume, much more likely to be a significant performance concern. In contrast, text-based diagnostic content is generally not shared beyond the individual or group running an application and is most often used to troubleshoot when something goes wrong. We suggest that a more systematic approach enabled by a logging facility (or 'logger)' similar to those routinely used by many communities would provide significant value to complex scientific applications. In the context of high-performance computing, an appropriate logger would provide specialized support for distributed and shared-memory parallelism and have low performance overhead. In this paper, we present our prototype implementation of pFlogger - a parallel Fortran-based logging framework, and assess its suitability for use in a complex scientific application.

An Assessment of Cumulative Axial and Torsional Fatigue in a Cobalt-Base Superalloy

NASA Technical Reports Server (NTRS)

Kalluri, Sreeramesh; Bonacuse, Peter J.

2010-01-01

Cumulative fatigue under axial and torsional loading conditions can include both load-order (higMow and low/high) as well as load-type sequence (axial/torsional and torsional/axial) effects. Previously reported experimental studies on a cobalt-base superalloy, Haynes 188 at 538 C, addressed these effects. These studies characterized the cumulative axial and torsional fatigue behavior under high amplitude followed by low amplitude (Kalluri, S. and Bonacuse, P. J., "Cumulative Axial and Torsional Fatigue: An Investigation of Load-Type Sequance Effects," in Multiaxial Fatigue and Deformation: Testing and Prediction, ASTM STP 1387, S. Kalluri, and P. J. Bonacuse, Eds., American Society for Testing and Materials, West Conshohocken, PA, 2000, pp. 281-301) and low amplitude followed by high amplitude (Bonacuse, P. and Kalluri, S. "Sequenced Axial and Torsional Cumulative Fatigue: Low Amplitude Followed by High Amplitude Loading," Biaxial/Multiaxial Fatigue and Fracture, ESIS Publication 31, A. Carpinteri, M. De Freitas, and A. Spagnoli, Eds., Elsevier, New York, 2003, pp. 165-182) conditions. In both studies, experiments with the following four load-type sequences were performed: (a) axial/axial, (b) torsional/torsional, (c) axial/torsional, and (d) torsional/axial. In this paper, the cumulative axial and torsional fatigue data generated in the two previous studies are combined to generate a comprehensive cumulative fatigue database on both the load-order and load-type sequence effects. This comprehensive database is used to examine applicability of the Palmgren-langer-Miner linear damage rule and a nonlinear damage curve approach for Haynes 188 subjected to the load-order and load-type sequencing described above. Summations of life fractions from the experiments are compared to the predictions from both the linear and nonlinear cumulative fatigue damage approaches. The significance of load-order versus load-type sequence effects for axial and torsional loading conditions is discussed. Possible reasons for the observed differences between the computed and observed summations of cycle fractions are rationalized in terms of the observed ever lutions of cyclic axial and shear stress ranges in the cumulative fatigue tests.

Physical activity and cohabitation status moderate the link between diabetes mellitus and cognitive performance in a community-dwelling elderly population in Germany

PubMed Central

Buchmann, Nikolaus; Tegeler, Christina; Steinhagen-Thiessen, Elisabeth

2017-01-01

Aims/Hypothesis The increasing number of people with dementia and cognitive impairments makes it essential to detect and prevent modifiable risk factors of dementia. This study focuses on type 2 diabetes mellitus, especially on undiagnosed cases and their increased risk of cognitive impairment. Furthermore, the potential of physical activity and social integration to moderate the relation between diabetes and cognitive impairment is assessed. Methods We used cross-sectional data from 1299 participants of the Berlin Aging Study II (BASE-II) aged between 60 to 84 years and performed logistic regression models to analyze the association of diabetes status, physical activity, and cohabitation status with poor cognitive performance. Cognitive performance was measured with the Consortium to Establish a Registry for Alzheimer's Disease (CERAD)-Plus test battery. Results Undiagnosed diabetes (odds ratio (OR) = 2.12, p = 0.031), physical inactivity (OR = 1.43, p = 0.008) and non-cohabiting (OR = 1.58, p = 0.002) were associated with an increased likelihood of poor cognitive performance. The highest odds were observed in participants who suffered from undiagnosed or insulin-dependent diabetes and, in addition, were inactive (undiagnosed diabetes: OR = 3.44, p = 0.003; insulin-dependent diabetes: OR = 6.19, p = 0.019) or lived alone (undiagnosed diabetes: OR = 4.46, p = 0.006; insulin-dependent diabetes: OR = 6.46 p = 0.052). Physical activity and cohabiting appeared to be beneficial. Conclusions/Interpretation Physical activity and cohabitation status moderate the link between diabetes mellitus and cognitive performance. Special attention should be paid to undiagnosed and insulin-dependent diabetes cases, which have a particularly high risk of poor cognitive performance. PMID:29073237

Efficacy of a Moderately Low Carbohydrate Diet in a 36-Month Observational Study of Japanese Patients with Type 2 Diabetes.

PubMed

Sanada, Mariko; Kabe, Chinatsu; Hata, Hisa; Uchida, Junichi; Inoue, Gaku; Tsukamoto, Yoko; Yamada, Yoshifumi; Irie, Junichiro; Tabata, Shogo; Tabata, Mitsuhisa; Yamada, Satoru

2018-04-24

We previously showed that a non-calorie-restricted, moderately low-carbohydrate diet (mLCD) is more effective than caloric restriction for glycemic and lipid profile control in patients with type 2 diabetes. To determine whether mLCD intervention is sustainable, effective, and safe over a long period, we performed a 36-month observational study. We sequentially enrolled 200 patients with type 2 diabetes and taught them how to follow the mLCD. We compared the following parameters pre- and post-dietary intervention in an outpatient setting: glycated hemoglobin (HbA1c), body weight, lipid profile (total cholesterol, low and high-density lipoprotein cholesterol, triglycerides), systolic and diastolic blood pressure, liver enzymes (aspartate aminotransferase, alanine aminotransferase), and renal function (urea nitrogen, creatinine, estimated glomerular filtration rate). Data from 157 participants were analyzed (43 were lost to follow-up). The following parameters decreased over the period of study: HbA1c (from 8.0 ± 1.5% to 7.5 ± 1.3%, p < 0.0001) and alanine aminotransferase (from 29.9 ± 23.6 to 26.2 ± 18.4 IL/L, p = 0.009). Parameters that increased were high-density lipoprotein cholesterol (from 58.9 ± 15.9 to 61.2 ± 17.4 mg/dL, p = 0.001) and urea nitrogen (from 15.9 ± 5.2 to 17.0 ± 5.4 mg/dL, p = 0.003). Over 36 months, the mLCD intervention showed sustained effectiveness (without safety concerns) in improving HbA1c, lipid profile, and liver enzymes in Japanese patients with type 2 diabetes.

A computational assessment of the electronic, thermoelectric, and defect properties of bournonite (CuPbSbS 3) and related substitutions

DOE PAGES

Faghaninia, Alireza; Yu, Guodong; Aydemir, Umut; ...

2017-02-08

Bournonite (CuPbSbS 3) is an earth-abundant mineral with potential thermoelectric applications. This material has a complex crystal structure (space group Pmn2 1 #31) and has previously been measured to exhibit a very low thermal conductivity (κ < 1 W m -1 K -1 at T ≥ 300 K). In this study, we employ high-throughput density functional theory calculations to investigate how the properties of the bournonite crystal structure change with elemental substitutions. Specifically, we compute the stability and electronic properties of 320 structures generated via substitutions {Na-K-Cu-Ag}{Si-Ge-Sn-Pb}{N-P-As-Sb-Bi}{O-S-Se-Te} in the ABCD 3 formula. We perform two types of transport calculations: themore » BoltzTraP model, which has been extensively tested, and a newer AMSET model that we have developed and which incorporates scattering effects. We discuss the differences in the model results, finding qualitative agreement except in the case of degenerate bands. Based on our calculations, we identify p-type CuPbSbSe 3 , CuSnSbSe 3 and CuPbAsSe 3 as potentially promising materials for further investigation. We additionally calculate the defect properties, finding that n-type behavior in bournonite and the selected materials is highly unlikely, and p-type behavior might be enhanced by employing Sb-poor synthesis conditions to prevent the formation of Sb Pb defects. Finally, we discuss the origins of various trends with chemical substitution, including the possible role of stereochemically active lone pair effects in stabilizing the bournonite structure and the effect of cation and anion selection on the calculated band gap.« less

Preclinical efficacy of the MDM2 inhibitor RG7112 in MDM2 amplified and TP53 wild-type glioblastomas

PubMed Central

Verreault, Maite; Schmitt, Charlotte; Goldwirt, Lauriane; Pelton, Kristine; Haidar, Samer; Levasseur, Camille; Guehennec, Jeremy; Knoff, David; Labussiere, Marianne; Marie, Yannick; Ligon, Azra H.; Mokhtari, Karima; Hoang-Xuan, Khe; Sanson, Marc; Alexander, Brian M; Wen, Patrick Y.; Delattre, Jean-Yves; Ligon, Keith L.; Idbaih, Ahmed

2016-01-01

Rationale p53 pathway alterations are key molecular events in glioblastoma (GBM). MDM2 inhibitors increase expression and stability of p53 and are presumed to be most efficacious in patients with TP53 wild-type and MDM2-amplified cancers. However, this biomarker hypothesis has not been tested in patients or patient-derived models for GBM. Methods We performed a preclinical evaluation of RG7112 MDM2 inhibitor, across a panel of 36 patient-derived GBM cell lines (PDCLs), each genetically characterized according to their P53 pathway status. We then performed a pharmacokinetic (PK) profiling of RG7112 distribution in mice and evaluated the therapeutic activity of RG7112 in orthotopic and subcutaneous GBM models. Results MDM2-amplified PDCLs were 44 times more sensitive than TP53 mutated lines that showed complete resistance at therapeutically attainable concentrations (avg. IC50 of 0.52 μM vs 21.9 μM). MDM4 amplified PDCLs were highly sensitive but showed intermediate response (avg. IC50 of 1.2 μM), whereas response was heterogeneous in TP53 wild-type PDCLs with normal MDM2/4 levels (avg. IC50 of 7.7 μM). In MDM2-amplified lines, RG7112 restored p53 activity inducing robust p21 expression and apoptosis. PK profiling of RG7112-treated PDCL intracranial xenografts demonstrated that the compound significantly crosses the blood-brain and the blood-tumor barriers. Most importantly, treatment of MDM2-amplified/TP53 wild-type PDCL-derived model (subcutaneous and orthotopic) reduced tumor growth, was cytotoxic, and significantly increased survival. Conclusion These data strongly support development of MDM2 inhibitors for clinical testing in MDM2-amplified GBM patients. Moreover, significant efficacy in a subset of non-MDM2 amplified models suggests that additional markers of response to MDM2 inhibitors must be identified. PMID:26482041

Intensive structured self-monitoring of blood glucose and glycemic control in noninsulin-treated type 2 diabetes: the PRISMA randomized trial.

PubMed

Bosi, Emanuele; Scavini, Marina; Ceriello, Antonio; Cucinotta, Domenico; Tiengo, Antonio; Marino, Raffaele; Bonizzoni, Erminio; Giorgino, Francesco

2013-10-01

We aimed to evaluate the added value of intensive self-monitoring of blood glucose (SMBG), structured in timing and frequency, in noninsulin-treated patients with type 2 diabetes. The 12-month, randomized, clinical trial enrolled 1,024 patients with noninsulin-treated type 2 diabetes (median baseline HbA1c, 7.3% [IQR, 6.9-7.8%]) at 39 diabetes clinics in Italy. After standardized education, 501 patients were randomized to intensive structured monitoring (ISM) with 4-point glycemic profiles (fasting, preprandial, 2-h postprandial, and postabsorptive measurements) performed 3 days/week; 523 patients were randomized to active control (AC) with 4-point glycemic profiles performed at baseline and at 6 and 12 months. Two primary end points were tested in hierarchical order: HbA1c change at 12 months and percentage of patients at risk target for low and high blood glucose index. Intent-to-treat analysis showed greater HbA1c reductions over 12 months in ISM (-0.39%) than in AC patients (-0.27%), with a between-group difference of -0.12% (95% CI, -0.210 to -0.024; P=0.013). In the per-protocol analysis, the between-group difference was -0.21% (-0.331 to -0.089; P=0.0007). More ISM than AC patients achieved clinically meaningful reductions in HbA1c (>0.3, >0.4, or >0.5%) at study end (P<0.025). The proportion of patients reaching/maintaining the risk target at month 12 was similar in ISM (74.6%) and AC (70.1%) patients (P=0.131). At visits 2, 3, and 4, diabetes medications were changed more often in ISM than in AC patients (P<0.001). Use of structured SMBG improves glycemic control and provides guidance in prescribing diabetes medications in patients with relatively well-controlled noninsulin-treated type 2 diabetes.

Diffusion-weighted imaging for the cellularity assessment and matrix characterization of soft tissue tumour.

PubMed

Robba, Tiziana; Chianca, Vito; Albano, Domenico; Clementi, Valeria; Piana, Raimondo; Linari, Alessandra; Comandone, Alessandro; Regis, Guido; Stratta, Maurizio; Faletti, Carlo; Borrè, Alda

2017-11-01

To evaluate whether apparent diffusion coefficient (ADC) of diffusion-weighted imaging (DWI) is able to investigate the histological features of soft tissue tumours. We reviewed MRIs of soft tissue tumours performed from 2012 to 2015 to calculate the average ADCs. We included 46 patients (27 male; mean age: 57 years, range 12-85 years) with histologically proven soft tissue tumours (10 benign, 2 intermediate 34 malignant) grouped into eight tumour type classes. An experienced pathologist assigned a semi-quantitative cellularity score (very high, high, medium and low) and tumour grading. The t test, ANOVA and linear regression were used to correlate ADC with clinicopathological data. Approximate receiver operating characteristic curves were created to predict possible uses of ADC to differentiate benign from malignant tumours. There was a significant difference (p < 0.01) in ADCs between these three groups excluding myxoid sarcomas. A significant difference was also evident between the tumour type classes (p < 0.001), grade II and III myxoid lesions (p < 0.05), tumour grading classes (p < 0.001) and cellularity scores classes (p < 0.001), with the lowest ADCs in the very high cellularity. While the linear regression analysis showed a significant relationship between ADC and tumour cellularity (r = 0.590, p ≤ 0.05) and grading (r = 0.437, p ≤ 0.05), no significant relationship was found with age, gender, tumour size and histological subtype. An optimal cut-off ADC value of 1.45 × 10 -3 mm 2 /s with 76.8% accuracy was found to differentiate benign from malignant tumours. DWI may offer adjunctive information about soft tissue tumours, but its clinical role is still to be defined.

High sequence variability among hemocyte-specific Kazal-type proteinase inhibitors in decapod crustaceans.

PubMed

Cerenius, Lage; Liu, Haipeng; Zhang, Yanjiao; Rimphanitchayakit, Vichien; Tassanakajon, Anchalee; Gunnar Andersson, M; Söderhäll, Kenneth; Söderhäll, Irene

2010-01-01

Crustacean hemocytes were found to produce a large number of transcripts coding for Kazal-type proteinase inhibitors (KPIs). A detailed study performed with the crayfish Pacifastacus leniusculus and the shrimp Penaeus monodon revealed the presence of at least 26 and 20 different Kazal domains from the hemocyte KPIs, respectively. Comparisons with KPIs from other taxa indicate that the sequences of these domains evolve rapidly. A few conserved positions, e.g. six invariant cysteines were present in all domain sequences whereas the position of P1 amino acid, a determinant for substrate specificity, varied highly. A study with a single crayfish animal suggested that even at the individual level considerable sequence variability among hemocyte KPIs produced exist. Expression analysis of four crayfish KPI transcripts in hematopoietic tissue cells and different hemocyte types suggest that some of these KPIs are likely to be involved in hematopoiesis or hemocyte release as they were produced in particular hemocyte types or maturation stages only.

Self-compensation in arsenic doping of CdTe

DOE PAGES

Ablekim, Tursun; Swain, Santosh K.; Yin, Wan -Jian; ...

2017-07-04

Efficient p-type doping in CdTe has remained a critical challenge for decades, limiting the performance of CdTe-based semiconductor devices. Arsenic is a promising p-type dopant; however, reproducible doping with high concentration is difficult and carrier lifetime is low. We systematically studied defect structures in As-doped CdTe using high-purity single crystal wafers to investigate the mechanisms that limit p-type doping. Two As-doped CdTe with varying acceptor density and two undoped CdTe were grown in Cd-rich and Te-rich environments. The defect structures were investigated by thermoelectric-effect spectroscopy (TEES), and first-principles calculations were used for identifying and assigning the experimentally observed defects. Measurementsmore » revealed activation of As is very low in both As-doped samples with very short lifetimes indicating strong compensation and the presence of significant carrier trapping defects. Defect studies suggest two acceptors and one donor level were introduced by As doping with activation energies at ~88 meV, ~293 meV and ~377 meV. In particular, the peak shown at ~162 K in the TEES spectra is very prominent in both As-doped samples, indicating a signature of AX-center donors. In conclusion, the AX-centers are believed to be responsible for most of the compensation because of their low formation energy and very prominent peak intensity in TEES spectra.« less

Self-compensation in arsenic doping of CdTe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ablekim, Tursun; Swain, Santosh K.; Yin, Wan -Jian

Efficient p-type doping in CdTe has remained a critical challenge for decades, limiting the performance of CdTe-based semiconductor devices. Arsenic is a promising p-type dopant; however, reproducible doping with high concentration is difficult and carrier lifetime is low. We systematically studied defect structures in As-doped CdTe using high-purity single crystal wafers to investigate the mechanisms that limit p-type doping. Two As-doped CdTe with varying acceptor density and two undoped CdTe were grown in Cd-rich and Te-rich environments. The defect structures were investigated by thermoelectric-effect spectroscopy (TEES), and first-principles calculations were used for identifying and assigning the experimentally observed defects. Measurementsmore » revealed activation of As is very low in both As-doped samples with very short lifetimes indicating strong compensation and the presence of significant carrier trapping defects. Defect studies suggest two acceptors and one donor level were introduced by As doping with activation energies at ~88 meV, ~293 meV and ~377 meV. In particular, the peak shown at ~162 K in the TEES spectra is very prominent in both As-doped samples, indicating a signature of AX-center donors. In conclusion, the AX-centers are believed to be responsible for most of the compensation because of their low formation energy and very prominent peak intensity in TEES spectra.« less

Solution-processable ambipolar diketopyrrolopyrrole-selenophene polymer with unprecedentedly high hole and electron mobilities.

PubMed

Lee, Junghoon; Han, A-Reum; Kim, Jonggi; Kim, Yiho; Oh, Joon Hak; Yang, Changduk

2012-12-26

There is a fast-growing demand for polymer-based ambipolar thin-film transistors (TFTs), in which both n-type and p-type transistor operations are realized in a single layer, while maintaining simplicity in processing. Research progress toward this end is essentially fueled by molecular engineering of the conjugated backbones of the polymers and the development of process architectures for device fabrication, which has recently led to hole and electron mobilities of more than 1.0 cm(2) V(-1) s(-1). However, ambipolar polymers with even higher performance are still required. By taking into account both the conjugated backbone and side chains of the polymer component, we have developed a dithienyl-diketopyrrolopyrrole (TDPP) and selenophene containing polymer with hybrid siloxane-solubilizing groups (PTDPPSe-Si). A synergistic combination of rational polymer backbone design, side-chain dynamics, and solution processing affords an enormous boost in ambipolar TFT performance, resulting in unprecedentedly high hole and electron mobilities of 3.97 and 2.20 cm(2) V(-1) s(-1), respectively.

RF performances of inductors integrated on localized p+-type porous silicon regions

PubMed Central

2012-01-01

To study the influence of localized porous silicon regions on radiofrequency performances of passive devices, inductors were integrated on localized porous silicon regions, full porous silicon sheet, bulk silicon and glass substrates. In this work, a novel strong, resistant fluoropolymer mask is introduced to localize the porous silicon on the silicon wafer. Then, the quality factors and resonant frequencies obtained with the different substrates are presented. A first comparison is done between the performances of inductors integrated on same-thickness localized and full porous silicon sheet layers. The effect of the silicon regions in the decrease of performances of localized porous silicon is discussed. Then, the study shows that the localized porous silicon substrate significantly reduces losses in comparison with high-resistivity silicon or highly doped silicon bulks. These results are promising for the integration of both passive and active devices on the same silicon/porous silicon hybrid substrate. PMID:23009746

Performance of Skutterudite-Based Modules

NASA Astrophysics Data System (ADS)

Nie, G.; Suzuki, S.; Tomida, T.; Sumiyoshi, A.; Ochi, T.; Mukaiyama, K.; Kikuchi, M.; Guo, J. Q.; Yamamoto, A.; Obara, H.

2017-05-01

Due to their excellent thermoelectric (TE) performance, skutterudite materials have been selected by many laboratories and companies for development of TE modules to recover power from waste heat at high temperatures (300°C to 600°C). After years of effort, we have developed reliable n- and p-type skutterudite materials showing maximum figure of merit ( ZT) of 1.0 at 550°C and 0.75 at 450°C, respectively. In this work, we systematically investigated the performance of a module made using these two kinds of skutterudite. We demonstrate ˜7.2% conversion efficiency for temperature of 600°C at the hot side of the module and 50°C at the cold side, and show that the module had excellent stability in the high-temperature environment. Further improving the TE performance of our skutterudites, the conversion efficiency reached ˜8.5% under the same condition.

Performance and temperature dependencies of proton irradiated n/p and p/n GaAs and n/p silicon cells

NASA Technical Reports Server (NTRS)

Weinberg, I.; Swartz, C. K.; Hart, R. E., Jr.

1985-01-01

n/p homojunction GaAs cells are found to be more radiation resistant than p/n heteroface GaAs under 10 MeV proton irradiation. Both GaAs cell types outperform conventional silicon n/p cells under the same conditions. An increased temperature dependency of maximum power for the GaAs n/p cells is attributed to differences in Voc between the two GaAs cell types. These results and diffusion length considerations are consistent with the conclusion that p-type GaAs is more radiation resistant than n-type and therefore that the n/p configuration is possibly favored for use in the space radiation environment. However, it is concluded that additional work is required in order to choose between the two GaAs cell configurations.

INTENSITY, DURATION AND TYPE OF PHYSICAL ACTIVITY REQUIRED TO IMPROVE FUNCTION IN KNEE OSTEOARTHRITIS

PubMed Central

KIRIHARA, RICARDO AKIHIRO; CATELAN, FELLIPE BRAVIM; FARIAS, FABIANE ELIZE SABINO DE; SILVA, CLEIDNÉIA APARECIDA CLEMENTE DA; CERNIGOY, CLAUDIA HELENA DE AZEVEDO; REZENDE, MÁRCIA UCHOA DE

2017-01-01

ABSTRACT Objective: To evaluate the effects of physical activity intensity, type and duration in patients with knee osteoarthritis (KOA). Methods: A retrospective study of 195 KOA patients who were followed for two years after receiving educational material about KOA with or without attending classes. The patients were evaluated at baseline and 24 months. At the evaluations, the patients answered questionnaires pertaining to pain and function (WOMAC, Lequesne, VAS and SF-36); reported the intensity, duration and type of exercise performed per week; and performed the Timed Up & Go (TUG) and Five Times Sit-to-Stand (FTSST) tests. Results: Increased age affected improvements in the TUG results (p=0.017). The type, intensity and duration of physical activity did not correlate with pain, function or quality of life improvements (p>0.05), but the TUG results were on average 4 seconds faster among the patients who practiced intense physical activity and/or exercised for more than 180 minutes per week and/or performed isolated weight training or swam compared with those who remained sedentary after 2 years (p=0.01; p<0.001; p=0.01; p=0.04, respectively). Conclusions: Patients with KOA should aim for intense physical activity and/or more than 180 minutes of exercise per week and/or weight training (bodybuilding) for relevant pain reduction and functional improvement.Level of Evidence II, Retrospective Study. PMID:28642646

Reliable file sharing in distributed operating system using web RTC

NASA Astrophysics Data System (ADS)

Dukiya, Rajesh

2017-12-01

Since, the evolution of distributed operating system, distributed file system is come out to be important part in operating system. P2P is a reliable way in Distributed Operating System for file sharing. It was introduced in 1999, later it became a high research interest topic. Peer to Peer network is a type of network, where peers share network workload and other load related tasks. A P2P network can be a period of time connection, where a bunch of computers connected by a USB (Universal Serial Bus) port to transfer or enable disk sharing i.e. file sharing. Currently P2P requires special network that should be designed in P2P way. Nowadays, there is a big influence of browsers in our life. In this project we are going to study of file sharing mechanism in distributed operating system in web browsers, where we will try to find performance bottlenecks which our research will going to be an improvement in file sharing by performance and scalability in distributed file systems. Additionally, we will discuss the scope of Web Torrent file sharing and free-riding in peer to peer networks.

Fiber type-specific muscle glycogen sparing due to carbohydrate intake before and during exercise.

PubMed

De Bock, K; Derave, W; Ramaekers, M; Richter, E A; Hespel, P

2007-01-01

The effect of carbohydrate intake before and during exercise on muscle glycogen content was investigated. According to a randomized crossover study design, eight young healthy volunteers (n = 8) participated in two experimental sessions with an interval of 3 wk. In each session subjects performed 2 h of constant-load bicycle exercise ( approximately 75% maximal oxygen uptake). On one occasion (CHO), they received carbohydrates before ( approximately 150 g) and during (1 g.kg body weight(-1).h(-1)) exercise. On the other occasion they exercised after an overnight fast (F). Fiber type-specific relative glycogen content was determined by periodic acid Schiff staining combined with immunofluorescence in needle biopsies from the vastus lateralis muscle before and immediately after exercise. Preexercise glycogen content was higher in type IIa fibers [9.1 +/- 1 x 10(-2) optical density (OD)/microm(2)] than in type I fibers (8.0 +/- 1 x 10(-2) OD/microm(2); P < 0.0001). Type IIa fiber glycogen content decreased during F from 9.6 +/- 1 x 10(-2) OD/microm(2) to 4.5 +/- 1 x 10(-2) OD/microm(2) (P = 0.001), but it did not significantly change during CHO (P = 0.29). Conversely, in type I fibers during CHO and F the exercise bout decreased glycogen content to the same degree. We conclude that the combination of carbohydrate intake both before and during moderate- to high-intensity endurance exercise results in glycogen sparing in type IIa muscle fibers.

A high-throughput cellular assay to quantify the p53-degradation activity of E6 from different human papillomavirus types.

PubMed

Gagnon, David; Archambault, Jacques

2015-01-01

A subset of human papillomaviruses (HPVs), known as the high-risk types, are the causative agents of cervical cancer and other malignancies of the anogenital region and oral mucosa. The capacity of these viruses to induce cancer and to immortalize cells in culture relies in part on a critical function of their E6 oncoprotein, that of promoting the poly-ubiquitination of the cellular tumor suppressor protein p53 and its subsequent degradation by the proteasome. Here, we describe a cellular assay to measure the p53-degradation activity of E6 from different HPV types. This assay is based on a translational fusion of p53 to Renilla luciferase (Rluc-p53) that remains sensitive to degradation by high-risk E6 and whose steady-state levels can be accurately measured in standard luciferase assays. The p53-degradation activity of any E6 protein can be tested and quantified in transiently transfected cells by determining the amount of E6-expression vector required to reduce by half the levels of RLuc-p53 luciferase activity (50 % effective concentration [EC50]). The high-throughput and quantitative nature of this assay makes it particularly useful to compare the p53-degradation activities of E6 from several HPV types in parallel.

Factors affecting the choice of type of delivery with breast feeding in Iranian mothers.

PubMed

Sharifi, Farangis; Nouraei, Soheila; Sharifi, Nader

2017-09-01

This study assessed the factors affecting the choice of type of delivery with breast feeding in Iranian mothers. This Cross section descriptive analytic study was performed using a random sampling technique, using data from 400 pregnant women who attended the maternity centers in Borazjan and Kazerun in Iran in 2014. A questionnaire covering demographic characteristics, mode of delivery and postpartum conditions was completed for each mother. Descriptive analysis and Chi square test were used along with SPSS 23 software to statistically analyze the data and p-value less than 0.05 was considered for statistical significance. In this study, the rate of normal delivery and cesarean operation are considered equal. In the main factors influencing the choice of delivery, mothers' education level (p=0.028) and pregnancy status (p=0.041) showed a significant relationship. Although no significant association between child nutrition with the type of delivery was found, duration of breastfeeding with the type of delivery showed significant association (p=0.046). Although cesarean delivery in many cases is life-saving for mother and fetus; in addition to medical indications, parents with higher education and pregnancy status are also important factors in increasing the rate of cesarean section compared to vaginal delivery. Babies of mothers with normal delivery had a longer time of breastfeeding. Further studies in Iran are necessary, regarding the reasons for high cesarean section and their outcomes.

Signaling pathways coordinating the alkaline pH response confer resistance to the hevein-type plant antimicrobial peptide Pn-AMP1 in Saccharomyces cerevisiae.

PubMed

Kwon, Youngho; Chiang, Jennifer; Tran, Grant; Giaever, Guri; Nislow, Corey; Hahn, Bum-Soo; Kwak, Youn-Sig; Koo, Ja-Choon

2016-12-01

Genome-wide screening of Saccharomyces cerevisiae revealed that signaling pathways related to the alkaline pH stress contribute to resistance to plant antimicrobial peptide, Pn-AMP1. Plant antimicrobial peptides (AMPs) are considered to be promising candidates for controlling phytopathogens. Pn-AMP1 is a hevein-type plant AMP that shows potent and broad-spectrum antifungal activity. Genome-wide chemogenomic screening was performed using heterozygous and homozygous diploid deletion pools of Saccharomyces cerevisiae as a chemogenetic model system to identify genes whose deletion conferred enhanced sensitivity to Pn-AMP1. This assay identified 44 deletion strains with fitness defects in the presence of Pn-AMP1. Strong fitness defects were observed in strains with deletions of genes encoding components of several pathways and complex known to participate in the adaptive response to alkaline pH stress, including the cell wall integrity (CWI), calcineurin/Crz1, Rim101, SNF1 pathways and endosomal sorting complex required for transport (ESCRT complex). Gene ontology (GO) enrichment analysis of these genes revealed that the most highly overrepresented GO term was "cellular response to alkaline pH". We found that 32 of the 44 deletion strains tested (72 %) showed significant growth defects compared with their wild type at alkaline pH. Furthermore, 9 deletion strains (20 %) exhibited enhanced sensitivity to Pn-AMP1 at ambient pH compared to acidic pH. Although several hundred plant AMPs have been reported, their modes of action remain largely uncharacterized. This study demonstrates that the signaling pathways that coordinate the adaptive response to alkaline pH also confer resistance to a hevein-type plant AMP in S. cerevisiae. Our findings have broad implications for the design of novel and potent antifungal agents.

Atomically-thin molecular layers for electrode modification of organic transistors

NASA Astrophysics Data System (ADS)

Gim, Yuseong; Kang, Boseok; Kim, Bongsoo; Kim, Sun-Guk; Lee, Joong-Hee; Cho, Kilwon; Ku, Bon-Cheol; Cho, Jeong Ho

2015-08-01

Atomically-thin molecular layers of aryl-functionalized graphene oxides (GOs) were used to modify the surface characteristics of source-drain electrodes to improve the performances of organic field-effect transistor (OFET) devices. The GOs were functionalized with various aryl diazonium salts, including 4-nitroaniline, 4-fluoroaniline, or 4-methoxyaniline, to produce several types of GOs with different surface functional groups (NO2-Ph-GO, F-Ph-GO, or CH3O-Ph-GO, respectively). The deposition of aryl-functionalized GOs or their reduced derivatives onto metal electrode surfaces dramatically enhanced the electrical performances of both p-type and n-type OFETs relative to the performances of OFETs prepared without the GO modification layer. Among the functionalized rGOs, CH3O-Ph-rGO yielded the highest hole mobility of 0.55 cm2 V-1 s-1 and electron mobility of 0.17 cm2 V-1 s-1 in p-type and n-type FETs, respectively. Two governing factors: (1) the work function of the modified electrodes and (2) the crystalline microstructures of the benchmark semiconductors grown on the modified electrode surface were systematically investigated to reveal the origin of the performance improvements. Our simple, inexpensive, and scalable electrode modification technique provides a significant step toward optimizing the device performance by engineering the semiconductor-electrode interfaces in OFETs.Atomically-thin molecular layers of aryl-functionalized graphene oxides (GOs) were used to modify the surface characteristics of source-drain electrodes to improve the performances of organic field-effect transistor (OFET) devices. The GOs were functionalized with various aryl diazonium salts, including 4-nitroaniline, 4-fluoroaniline, or 4-methoxyaniline, to produce several types of GOs with different surface functional groups (NO2-Ph-GO, F-Ph-GO, or CH3O-Ph-GO, respectively). The deposition of aryl-functionalized GOs or their reduced derivatives onto metal electrode surfaces dramatically enhanced the electrical performances of both p-type and n-type OFETs relative to the performances of OFETs prepared without the GO modification layer. Among the functionalized rGOs, CH3O-Ph-rGO yielded the highest hole mobility of 0.55 cm2 V-1 s-1 and electron mobility of 0.17 cm2 V-1 s-1 in p-type and n-type FETs, respectively. Two governing factors: (1) the work function of the modified electrodes and (2) the crystalline microstructures of the benchmark semiconductors grown on the modified electrode surface were systematically investigated to reveal the origin of the performance improvements. Our simple, inexpensive, and scalable electrode modification technique provides a significant step toward optimizing the device performance by engineering the semiconductor-electrode interfaces in OFETs. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr03307a

Anesthesiology resident personality type correlates with faculty assessment of resident performance.

PubMed

Schell, Randall M; Dilorenzo, Amy N; Li, Hsin-Fang; Fragneto, Regina Y; Bowe, Edwin A; Hessel, Eugene A

2012-11-01

To study the association between anesthesiology residents' personality preference types, faculty evaluations of residents' performance, and knowledge. Convenience sample and prospective study. Academic department of anesthesiology. Consenting anesthesiology residents (n = 36). All participants completed the Myers Briggs Type Indicator® (MBTI®). All residents' 6-month summation of daily focal evaluations completed by faculty [daily performance score (DPS); 1 = unsatisfactory, 2 = needs improvement, 3 = meets expectations, 4 = exceeds expectations], as well as a global assessment of performance (GAP) score based on placement of each resident into perceived quartile compared with their peers (ie,1 = first, or top, quartile) by senior faculty (n = 7) who also completed the MBTI, were obtained. The resident MBTI personality preferences were compared with the DPS and GAP scores, the United States Medical Licensing Examination (USMLE) I and II scores, and faculty MBTI personality type. There was no association between personality preference type and performance on standardized examinations (USMLE I, II). The mean GAP score was better (higher quartile score) for Extraverts than Introverts (median 2.0 vs 2.6, P = 0.0047) and for Sensing versus Intuition (median 2.0 vs 2.6, P = 0.0206) preference. Faculty evaluator MBTI preference type did not influence the GAP scores they assigned residents. Like GAP, the DPS was better for residents with Sensing versus Intuition preference (median 3.5 vs 3.3, P = 0.0111). No difference in DPS was noted between Extraverts and Introverts. Personality preference type was not associated with resident performance on standardized examinations, but it was associated with faculty evaluations of resident performance. Residents with Sensing personality preference were evaluated more favorably on global and focal faculty evaluations than those residents who chose the Intuition preference. Extraverted residents were evaluated more favorably on global but not focal assessment of performance. Copyright © 2012 Elsevier Inc. All rights reserved.

Achilles tendon adaptation in cross-country runners across a competitive season.

PubMed

Stanley, L E; Lucero, A; Mauntel, T C; Kennedy, M; Walker, N; Marshall, S W; Padua, D A; Berkoff, D J

2018-01-01

Ultrasound tissue characterization (UTC) is an imaging tool used to quantify tendon structural integrity. UTC has quantified Achilles tendon (AT) acute response to load in athletes; however, AT response to cumulative load over a season is unknown. The purpose of this study was to evaluate AT response across a four-month competitive season in collegiate cross-country (XC) runners. Participants (n=21; male=9, female=12; age=19.8±1.2 years; height=171.9±8.9 cm; weight=60.2±8.5 kg) were imaged using the UTC device with a 10-MHz linear-array transducer mounted in a tracking device. The device captures images at 0.2 mm intervals along the AT. UTC algorithms quantified the stability of pixel brightness over every 17 contiguous transverse images into four echo types (I-IV). A total of 168 scans (n=21, bilateral limbs) were performed monthly across the four-month season (Aug=M1, Sep=M2, Oct=M3, Nov=M4). Echo-type percentages (%) were calculated from each scan. Generalized estimating equations (GEE) linear regression models evaluated echo-type % change (β) over the season (M1=reference). Type I increased from M1 to M4 (β=9.10, P<.01; 95%CI: 7.01, 11.21) and Type II decreased from M1 to M3 (β=-2.71, P=.018; 95%CI: -4.96, -0.47) and M1 to M4 (β=-10.19, P<.01; 95%CI: -12.22, -8.17). Type III increased from M1 to M3 (β=0.42, P=.003; 95%CI: 0.19, 0.65) and M1 to M4 (β=0.49, P=.002; 95%CI: 0.18, 0.81), Type IV increased from M1 to M4 (β=0.57, P<.01; 95%CI: 0.29, 0.84). A positive adaptation in AT structural integrity was observed over the XC season, with a ~10% shift from Type II to Type I UTC echo types, suggesting AT resilience to a competitive season of repetitive loading in highly trained runners. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Profiling of Extracellular Toxins Associated with Diarrhetic Shellfish Poison in Prorocentrum lima Culture Medium by High-Performance Liquid Chromatography Coupled with Mass Spectrometry

PubMed Central

Pan, Lei; Chen, Junhui; Shen, Huihui; He, Xiuping; Li, Guangjiu; Song, Xincheng; Zhou, Deshan; Sun, Chengjun

2017-01-01

Extracellular toxins released by marine toxigenic algae into the marine environment have attracted increasing attention in recent years. In this study, profiling, characterization and quantification of extracellular toxin compounds associated with diarrhetic shellfish poison (DSP) in the culture medium of toxin-producing dinoflagellates were performed using high-performance liquid chromatography–high-resolution mass spectrometry/tandem mass spectrometry for the first time. Results showed that solid-phase extraction can effectively enrich and clean the DSP compounds in the culture medium of Prorocentrum lima (P. lima), and the proposed method achieved satisfactory recoveries (94.80%–100.58%) and repeatability (relative standard deviation ≤9.27%). Commercial software associated with the accurate mass information of known DSP toxins and their derivatives was used to screen and identify DSP compounds. Nine extracellular DSP compounds were identified, of which seven toxins (including OA-D7b, OA-D9b, OA-D10a/b, and so on) were found in the culture medium of P. lima for the first time. The results of quantitative analysis showed that the contents of extracellular DSP compounds in P. lima culture medium were relatively high, and the types and contents of intracellular and extracellular toxins apparently varied in the different growth stages of P. lima. The concentrations of extracellular okadaic acid and dinophysistoxin-1 were within 19.9–34.0 and 15.2–27.9 μg/L, respectively. The total concentration of the DSP compounds was within the range of 57.70–79.63 μg/L. The results showed that the proposed method is an effective tool for profiling the extracellular DSP compounds in the culture medium of marine toxigenic algae. PMID:28974018

Profiling of Extracellular Toxins Associated with Diarrhetic Shellfish Poison in Prorocentrum lima Culture Medium by High-Performance Liquid Chromatography Coupled with Mass Spectrometry.

PubMed

Pan, Lei; Chen, Junhui; Shen, Huihui; He, Xiuping; Li, Guangjiu; Song, Xincheng; Zhou, Deshan; Sun, Chengjun

2017-09-30

Extracellular toxins released by marine toxigenic algae into the marine environment have attracted increasing attention in recent years. In this study, profiling, characterization and quantification of extracellular toxin compounds associated with diarrhetic shellfish poison (DSP) in the culture medium of toxin-producing dinoflagellates were performed using high-performance liquid chromatography-high-resolution mass spectrometry/tandem mass spectrometry for the first time. Results showed that solid-phase extraction can effectively enrich and clean the DSP compounds in the culture medium of Prorocentrum lima ( P. lima ), and the proposed method achieved satisfactory recoveries (94.80%-100.58%) and repeatability (relative standard deviation ≤9.27%). Commercial software associated with the accurate mass information of known DSP toxins and their derivatives was used to screen and identify DSP compounds. Nine extracellular DSP compounds were identified, of which seven toxins (including OA-D7b, OA-D9b, OA-D10a/b, and so on) were found in the culture medium of P. lima for the first time. The results of quantitative analysis showed that the contents of extracellular DSP compounds in P. lima culture medium were relatively high, and the types and contents of intracellular and extracellular toxins apparently varied in the different growth stages of P. lima . The concentrations of extracellular okadaic acid and dinophysistoxin-1 were within 19.9-34.0 and 15.2-27.9 μg/L, respectively. The total concentration of the DSP compounds was within the range of 57.70-79.63 μg/L. The results showed that the proposed method is an effective tool for profiling the extracellular DSP compounds in the culture medium of marine toxigenic algae.

Biomechanical differences between unilateral and bilateral landings from a jump: gender differences.

PubMed

Pappas, Evangelos; Hagins, Marshall; Sheikhzadeh, Ali; Nordin, Margareta; Rose, Donald

2007-07-01

To determine the effect of landing type (unilateral vs. bilateral) and gender on the biomechanics of drop landings in recreational athletes. This study used a repeated measures design to compare bilateral and unilateral landings in male and female athletes. A repeated measures multivariate analysis of variance (type of landing*gender) was performed on select variables. Biomechanics laboratory. Sixteen female and 16 male recreational athletes. Kinetic, kinematic, and electromyographic (EMG) data were collected on participants while performing bilateral and unilateral landings from a 40-cm platform. Compared to bilateral landings, subjects performed unilateral landings with increased knee valgus, decreased knee flexion at initial contact, decreased peak knee flexion, decreased relative hip adduction, and increased normalized EMG of the rectus femoris, medial hamstrings, lateral hamstrings, and medial gastrocnemius (P < 0.005). During both types of landing, females landed with increased knee valgus and normalized vertical ground reaction force (VGRF) compared to males (P < 0.009), however, the interaction of landing type*gender was not significant (P = 0.29). Compared to bilateral landings, male and female recreational athletes performed unilateral landings with significant differences in knee kinematic and EMG variables. Female athletes landed with increased knee valgus and VGRF compared to males during both types of landing.