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1.
Nanotechnology ; 26(35): 355704, 2015 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-26245930

RESUMO

The production of large quantities of single crystalline semiconducting ZnO nanowires (NWs) at low cost can offer practical solutions to realizing several novel electronic/optoelectronic and sensor applications on an industrial scale. The present work demonstrates high-density single crystalline NWs synthesized by a multiple cycle hydrothermal process at ∼100 °C. The high carrier concentration in such ZnO NWs is greatly suppressed by a simple low cost thermal annealing step in ambient air at ∼450 °C. Single ZnO NW FETs incorporating these modified NWs are characterized, revealing strong metal work function-dependent charge transport, unobtainable with as-grown hydrothermal ZnO NWs. Single ZnO NW FETs with Al as source and drain (s/d) contacts show excellent performance metrics, including low off-state currents (fA range), high on/off ratio (10(5)-10(7)), steep subthreshold slope (<600 mV/dec) and excellent field-effect carrier mobility (5-11 cm(2)/V-s). Modified ZnO NWs with platinum s/d contacts demonstrate excellent Schottky transport characteristics, markedly different from a reference ZnO NW device with Al contacts. This included abrupt reverse bias current-voltage saturation characteristics and positive temperature coefficient (∼0.18 eV to 0.13 eV). This work is envisaged to benefit many areas of hydrothermal ZnO NW research, such as NW FETs, piezoelectric energy recovery, piezotronics and Schottky diodes.

3.
Front Psychol ; 11: 503153, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33101111

RESUMO

Abusive supervision, defined as subordinates' perception of the extent to which supervisors engage in the sustained display of hostile verbal and non-verbal behaviors, excluding physical contact, is associated with various negative outcomes. This has made it easy for researchers to overlook the possibility that some supervisors regret their bad behavior and express remorse for their actions. Hence, we know little about how subordinates react to the perception that their supervisor is remorseful and how this perception affects the outcomes of supervisors' undesired behavior. Specifically, drawing on the social exchange theory (SET) and displace revenge literature, this study explains how abusive supervision leads to victims' service sabotage behavior. In addition, this study also investigates how perceived supervisors' remorse (PSR) mitigates the adverse effects of abusive supervision. Based on time-lagged, dyadic data (63 supervisors, 212 subordinates) from Chinese individuals, this study found support for all the proposed relationships, i.e., abusive supervision leads to service sabotage through the mediating effect of revenge desire. The findings also conclude that PSR lessens the detrimental effects of abusive supervision on victims' behavior with their customers. Finally, this research contributes to service sabotage literature by highlighting the possibility where abusive supervisors cause service sabotage behavior among victims. This study also shows the importance of PSR's role in decreasing service sabotage behavior exhibited by victims of abusive supervisors in the service sector.

4.
ACS Appl Mater Interfaces ; 9(1): 573-584, 2017 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-28001361

RESUMO

The production of high-quality semiconducting nanostructures with optimized electrical, optical, and electromechanical properties is important for the advancement of next-generation technologies. In this context, we herein report on highly obliquely aligned single-crystalline zinc oxide nanosheets (ZnO NSs) grown via the vapor-liquid-solid approach using r-plane (01-12) sapphire as the template surface. The high structural and optical quality of as-grown ZnO NSs has been confirmed using high-resolution transmission electron microscopy and temperature-dependent photoluminescence, respectively. To assess the potential of our NSs as effective building materials in high-performance flexible electronics, we fabricate organic (parylene C)/inorganic (ZnO NS) hybrid field-effect transistor (FET) devices on flexible substrates using room-temperature assembly processes. Extraction of key FET performance parameters suggests that as-grown ZnO NSs can successfully function as excellent n-type semiconducting modules. Such devices are found to consistently show very high on-state currents (Ion) > 40 µA, high field-effect mobility (µeff) > 200 cm2/(V s), exceptionally high on/off current modulation ratio (Ion/off) of around 109, steep subthreshold swing (s-s) < 200 mV/decade, very low hysteresis, and negligible threshold voltage shifts with prolonged electrical stressing (up to 340 min). The present study delivers a concept of integrating high-quality ZnO NS as active semiconducting elements in flexible electronic circuits.

5.
Int J Antimicrob Agents ; 24 Suppl 1: S32-4, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15364303

RESUMO

Urinary tract infection (UTI) causes significant illness in the first 2 years of life. The diagnosis in most developing countries is often overlooked due to the tedious nature of obtaining urine from these young ones who would not void voluntarily. Misdiagnosis very often lead to avoidable ill health and long-term renal damage. There is a need to diagnose UTI in febrile infants to alert clinicians. A prospective study of febrile infants aged up to 12 months on admission was undertaken in a 6-months period. Urine specimen was obtained by supra pubic aspiration and investigated. Out of 150 urine samples screened for UTI, 45 (30%) had positive bacterial growth. Escherichia coli (32%) and Proteus sp. (22%) formed more than 50% of the total isolates. The Gram positive bacteria isolated was Staphylococcus aureus representing 11%. All isolates were susceptible to cefuroxime and resistant to ampicillin. Susceptibility to amoxicillin/clavulanic acid was 77.8% and to nitrofurantoin was 67%. Only 11.1% of isolates were susceptible to cotrimoxazole. These results indicate that UTI is a common cause of pyrexia in infants requiring admission. These infants when clinically diagnosed as having UTI are treated with ampicillin and cotrimoxazole. They do not have the benefit of further investigation for renal abnormalities and subsequent antibiotic prophylactics to prevent recurrent infection, which could result in renal scarring and its associated problems later.


Assuntos
Infecções Bacterianas/complicações , Febre/etiologia , Infecções Urinárias/complicações , Antibacterianos/farmacologia , Infecções Bacterianas/microbiologia , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/isolamento & purificação , Feminino , Gana , Humanos , Lactente , Recém-Nascido , Masculino , Testes de Sensibilidade Microbiana , Estudos Prospectivos , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificação , Infecções Urinárias/microbiologia
6.
Nanoscale Res Lett ; 9(1): 379, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25136283

RESUMO

A perfect control of nanostructure growth is a prerequisite for the development of electronic and optoelectronic device/systems. In this article, we demonstrate the growth of various ZnO-derived nanostructures, including well-ordered arrays of high aspect ratio single crystalline nanowires with preferred growth direction along the [0001] axis, nanowalls, and hybrid nanowire-nanowall structures. The growths of the various ZnO nanostructures have been carried out on SiC substrates in a horizontal furnace, using Au thin film as catalyst. From experimental observations, we have ascribed the growth mechanisms of the different ZnO nanostructures to be a combination of catalytic-assisted and non-catalytic-assisted vapor-liquid-solid (VLS) processes. We have also found that the different ZnO nanoarchitectures' material evolution is governed by a Zn cluster drift effects on the SiC surface mainly driven by growth temperature. Au thin film thickness, growth time, and temperature are the parameters to optimize in order to obtain the different ZnO nanoarchitectures.

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