738 research outputs found

    Efficacy of a self-help manual in increasing resilience in carers of adults with depression in Thailand

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    Caring for a person with a mental illness can have adverse effects on caregivers; however, little is known about how best to help such caregivers. The aim of the present study was to examine the efficacy of a cognitive behaviour therapy-guided self-help manual in increasing resilience in caregivers of individuals with depression, in comparison to caregivers who receive routine support only. A randomized, controlled trial was conducted, following CONSORT guidelines, with 54 caregivers allocated to parallel intervention (self-help manual) (n = 27) or control (standard support) (n = 27) groups. Resilience was assessed at baseline, post-test (week 8), and follow up (week 12). Intention-to-treat analyses were undertaken. Repeated-measures ANOVA indicated a significant difference in resilience scores between the three time points, showing a large effect. Pairwise comparisons between intervention and control groups indicated resilience to be significantly different between baseline and post-test, and between baseline and follow up, but not between post-test and follow up. Overall, the intervention group showed a slightly greater increase in resilience over time than the control group; however, the time–group interaction was not significant. Guided self-help is helpful in improving caregivers’ resilience and could be used as an adjunct to the limited support provided to carers by mental health nurses and other clinicians

    Leaping and Landing in Brave Spaces

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    Vapor-fed electrolysis of water has been performed using membrane-electrode assemblies (MEAs) incorporating earth-abundant catalysts and bipolar membranes (BPMs). Catalyst films containing CoP nanoparticles, carbon black, and Nafion were synthesized, characterized, and integrated into cathodes of MEAs. The CoP-containing MEAs exhibited stable (>16 h) vapor-fed electrolysis of water at room temperature at a current density of 10 mA cm⁻² with 350 mV of additional overvoltage relative to MEA's formed from Pt/C cathodic electrocatalysts due to slower hydrogen-evolution reaction kinetics under vapor-fed conditions and fewer available triple-phase boundaries in the catalyst film. Additionally, catalyst films containing a [NiFe]-layered double hydroxide ([NiFe]-LDH) as well as a hydroxide ion conductor, hexamethyl-p-terphenyl poly(benzimidazolium) (HMT-PMBI), were synthesized, characterized, and integrated into the anodes of the MEAs. The [NiFe]-LDH-containing MEAs exhibited overvoltages at 10 mA cm⁻² that were similar to those of IrO_x-containing MEAs for vapor-fed electrolysis of water at room temperature. A BPM was formed by pairing Nafion with HMT-PMBI, resulting in a locally alkaline environment of HMT-PMBI to stabilize the [NiFe]-LDH and a locally acidic environment to stabilize the CoP. BPM-based MEAs were stable (>16 h) for vapor-fed electrolysis of water at room temperature at a current density of 10 mA cm⁻², with a change in the pH gradient of 1 unit over 16 h of electrolysis for IrOx-containing MEAs. The stability of [NiFe]-LDH-based MEAs under vapor-fed conditions was dependent on the catalyst film morphology and resulting BPM interface, with stable operation at 10 mA cm⁻² achieved for 16 h. All MEAs exhibited a drift in the operating voltage over time associated with dehydration. These results demonstrate that earth-abundant catalysts and BPMs can be incorporated into stable, room-temperature, vapor-fed water-splitting cells operated at 10 mA cm⁻²

    Local musicking: theme and variations

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    A noção de musicar local vem sendo experimentada em um projeto temático do qual as três organizadoras deste dossiê participam. Desde 2016, temos orientado nossas pesquisas em torno desta expressão que une o conceito de musicar – traduzido de musicking de Christopher Small – com a noção de localidade, pensada a partir das considerações de autores como Arjun Appadurai e Ruth Finnegan. Musicar, na acepção de Small (1998), é utilizado para se referir a qualquer forma de engajamento com a música, entendida não apenas em seus aspectos formais (a obra musical), mas igualmente como performance, fruição, consumo, transmissão musical etc.The notion of local musicking is being experimented in a thematic project, in which the three organizers for this dossier participate. Since 2016, we have been focusing our researches towards this expression which links the concept of musicking - from Christopher Small - with the notion of locality, thought from the considerations of authors like Arjun Appadurai and Ruth Finnegan. Musicking, in the terms of Small (1998), refers to any form of engagement with music, taken not only in its formal aspects (the musical piece), but also  as performance, fruition, acquisition, musical transmission etc

    Heterostructures of skutterudites and germanium antimony tellurides – structure analysis and thermoelectric properties of bulk samples

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    Heterostructures of germanium antimony tellurides with skutterudite-type precipitates are promising thermoelectric materials due to low thermal conductivity and multiple ways of tuning their electronic transport properties. Materials with the nominal composition [CoSb2(GeTe)_(0.5)]_x(GeTe)_(10.5)Sb_2Te_3 (x = 0–2) contain nano- to microscale precipitates of skutterudite-type phases which are homogeneously distributed. Powder X-ray diffraction reveals that phase transitions of the germanium antimony telluride matrix depend on its GeTe content. These are typical for this class of materials; however, the phase transition temperatures are influenced by heterostructuring in a beneficial way, yielding a larger existence range of the intrinsically nanostructured pseudocubic structure of the matrix. Using microfocused synchrotron radiation in combination with crystallite pre-selection by means of electron microscopy, single crystals of the matrix as well as of the precipitates were examined. They show nano-domain twinning of the telluride matrix and a pronounced structure distortion in the precipitates caused by GeTe substitution. Thermoelectric figures of merit of 1.4 ± 0.3 at 450 °C are observed. In certain temperature ranges, heterostructuring involves an improvement of up to 30% compared to the homogeneous material

    TAGS-related indium compounds and their thermoelectric properties – the solid solution series (GeTe)_xAgIn_ySb_(1-y)Te_2 (x = 1–12; y = 0.5 and 1)

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    Various members of the solid solution series (GeTe)_xAgIn_ySb_(1−y)Te_2 can be obtained by quenching high-temperature phases (x = 12 for y = 1 and x > 5 for y = 0.5). In contrast, high-temperature and high-pressure conditions (2.5 GPa, 350 °C) are required for the synthesis of members with In contents >3.6 atom% (such as x 5 adopt the α-GeTe structure type (3 + 3 coordination). Thus, in all samples investigated, 3 or 4 cations are disordered at one Wyckoff position. The quenched high-temperature or high-pressure phases, respectively, are almost homogeneous. Their powder X-ray diffraction patterns suggest pure phases; yet, high-resolution electron microscopy occasionally reveals a very small extent of nanoscopic precipitates as well as dislocations and twinning. (GeTe)_(5.5)AgIn_(0.5)Sb_(0.5)Te_2 shows a maximal ZT value of 0.75 even when (partial) decomposition into the TAGS material (GeTe)_(11)AgSbTe_2 and chalcopyrite-type AgInTe_2 has occurred at 300 °C. (GeTe)_(5.5)AgInTe_2 prepared under high-pressure conditions exhibits a ZT value of 0.6 at 125 °C, i.e. far below the decomposition temperature and thus is an interesting new low-temperature thermoelectric material

    Beam power scale-up in MEMS based multi-beam ion accelerators

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    We report on the development of multi-beam RF linear ion accelerators that are formed from stacks of low cost wafers and describe the status of beam power scale-up using an array of 120 beams. The total argon ion current extracted from the 120-beamlet extraction column was 0.5 mA. The measured energy gain in each RF gap reached as high as 7.25 keV. We present a path of using this technology to achieve ion currents >1 mA and ion energies >100 keV for applications in materials processing

    Thermoregulatory, metabolic, and cardiovascular responses during 88 min of full-body ice immersion - A case study.

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    Exposure to extreme cold environments is potentially life-threatening. However, the world record holder of full-body ice immersion has repeatedly demonstrated an extraordinary tolerance to extreme cold. We aimed to explore thermoregulatory, metabolic, and cardiovascular responses during 88 min of full-body ice immersion. We continuously measured gastrointestinal temperature (Tgi ), skin temperature (Tskin), blood pressure, and heart rate (HR). Oxygen consumption (VO2 ) was measured at rest, and after 45 and 88 min of ice immersion, in order to calculate the metabolic heat production. Tskin dropped significantly (28-34°C to 4-15°C) and VO2 doubled (5.7-11.3 ml kg-1  min-1 ), whereas Tgi (37.6°C), HR (72 bpm), and mean arterial pressure (106 mmHg) remained stable during the first 30 min of cold exposure. During the remaining of the trial, Tskin and VO2 remained stable, while Tgi gradually declined to 37.0°C and HR and mean arterial blood pressure increased to maximum values of 101 bpm and 115 mmHg, respectively. Metabolic heat production in rest was 169 W and increased to 321 W and 314 W after 45 and 80 min of ice immersion. Eighty-eight minutes of full-body ice immersion resulted in minor changes of Tgi and cardiovascular responses, while Tskin and VO2 changed markedly. These findings may suggest that our participant can optimize his thermoregulatory, metabolic, and cardiovascular responses to challenge extreme cold exposure

    White Matter Deficits Assessed by Diffusion Tensor Imaging and Cognitive Dysfunction in Psychostimulant Users With Comorbid Human Immunodeficiency Virus Infection

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    Background Psychostimulant drug use is commonly associated with drug-related infection, including the human immunodeficiency virus (HIV). Both psychostimulant use and HIV infection are known to damage brain white matter and impair cognition. To date, no study has examined white matter integrity using magnetic resonance imaging (MRI) diffusion tensor imaging (DTI) in chronic psychostimulant users with comorbid HIV infection, and determined the relationship of white matter integrity to cognitive function. Methods Twenty-one subjects (mean age 37.5 ± 9.0 years) with a history of heavy psychostimulant use and HIV infection (8.7 ± 4.3 years) and 22 matched controls were scanned on a 3T MRI. Fractional anisotropy (FA) values were calculated with DTI software. Four regions of interest were manually segmented, including the genu of the corpus callosum, left and right anterior limbs of the internal capsule, and the anterior commissure. Subjects also completed a neurocognitive battery and questionnaires about physical and mental health. Results The psychostimulant using, HIV positive group displayed decreased white matter integrity, with significantly lower FA values for all white matter tracts (p < 0.05). This group also exhibited decreased cognitive performance on tasks that assessed cognitive set-shifting, fine motor speed and verbal memory. FA values for the white matter tracts correlated with cognitive performance on many of the neurocognitive tests. Conclusions White matter integrity was thus impaired in subjects with psychostimulant use and comorbid HIV infection, which predicted worsened cognitive performance on a range of tests. Further study on this medical comorbidity is required

    Nanostructures in Te/Sb/Ge/Ag (TAGS) Thermoelectric Materials Induced by Phase Transitions Associated with Vacancy Ordering

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    Te/Sb/Ge/Ag (TAGS) materials with rather high concentrations of cation vacancies exhibit improved thermoelectric properties as compared to corresponding conventional TAGS (with constant Ag/Sb ratio of 1) due to a significant reduction of the lattice thermal conductivity. There are different vacancy ordering possibilities depending on the vacancy concentration and the history of heat treatment of the samples. In contrast to the average α-GeTe-type structure of TAGS materials with cation vacancy concentrations <3%, quenched compounds like Ge_(0.53)Ag_(0.13)Sb_(0.27)□_(0.07)Te_1 and Ge_(0.61)Ag_(0.11)Sb_(0.22)□_(0.06)Te_1 exhibit “parquet-like” multidomain nanostructures with finite intersecting vacancy layers. These are perpendicular to the pseudocubic 111 directions but not equidistantly spaced, comparable to the nanostructures of compounds (GeTe)_nSb_2Te_3. Upon heating, the nanostructures transform into long-periodically ordered trigonal phases with parallel van der Waals gaps. These phases are slightly affected by stacking disorder but distinctly different from the α-GeTe-type structure reported for conventional TAGS materials. Deviations from this structure type are evident only from HRTEM images along certain directions or very weak intensities in diffraction patterns. At temperatures above 400 °C, a rock-salt-type high-temperature phase with statistically disordered cation vacancies is formed. Upon cooling, the long-periodically trigonal phases are reformed at the same temperature. Quenched nanostructured Ge_(0.53)Ag_(0.13)Sb_(0.27)□_(0.07)Te_1 and Ge_(0.61)Ag_(0.11)Sb_(0.22)□_(0.06)Te_1 exhibit ZT values as high as 1.3 and 0.8, respectively, at 160 °C, which is far below the phase transition temperatures. After heat treatment, i.e., without pronounced nanostructure and when only reversible phase transitions occur, the ZT values of Ge_(0.53)Ag_(0.13)Sb_(0.27)□_(0.07)Te_1 and Ge_(0.61)Ag_(0.11)Sb_(0.22)□_(0.06)Te_1 with extended van der Waals gaps amount to 1.6 at 360 °C and 1.4 at 410 °C, respectively, which is at the top end of the range of high-performance TAGS materials
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