The perovskite type Gd/sub 1-x/Sr/sub x/FeO/sub 3-/spl delta// (x=0.0, 0.25, 0.5, 0.75 and 1.0) system has been studied by X-rays, Mohr's salt analysis, and Mossbauer spectroscopy. From the results ...of X-ray diffraction measurement the structure of the Gd/sub 1-x/Sr/sub x/FeO/sub 3-/spl delta// system is orthorhombic with x values of 0.0, 0.25 and 0.5, and cubic with the x values of 0.75 and 1.0. Mossbauer spectra of Gd/sub 1-x/Sr/sub x/FeO/sub 3-/spl delta// have been taken at various temperatures ranging from 13 to 800 K. Analysis of Mossbauer spectra for this system demonstrated the existence of the mixed valence states of iron and the coordination state of Fe/sup 3+/ and Fe/sup 4+/ ions. The Neel temperature decreases linearly with Sr concentration, suggesting that the superexchange interaction for Gd-O-Fe link is stronger than that for Sr-O-Fe link.< >
Recent advances in flexible and stretchable electronics have led to a surge of electronic skin (e-skin)–based health monitoring platforms. Conventional wireless e-skins rely on rigid integrated ...circuit chips that compromise the overall flexibility and consume considerable power. Chip-less wireless e-skins based on inductor-capacitor resonators are limited to mechanical sensors with low sensitivities. We report a chip-less wireless e-skin based on surface acoustic wave sensors made of freestanding ultrathin single-crystalline piezoelectric gallium nitride membranes. Surface acoustic wave–based e-skin offers highly sensitive, low-power, and long-term sensing of strain, ultraviolet light, and ion concentrations in sweat. We demonstrate weeklong monitoring of pulse. These results present routes to inexpensive and versatile low-power, high-sensitivity platforms for wireless health monitoring devices.
Chip-less electronic skin
Flexible electronic materials, or e-skins, can be limited by the need to include rigid components. A range of techniques have emerged to bypass this problem, including approaches for wireless communication and charging based on silicon, carbon nanotubes, or conducting polymers. Kim
et al
. show that epitaxially grown, single-crystalline gallium nitride films on flexible substrates can be used for chip-less, flexible e-skins. The main advantage is that the material is flexible and breathable, thus providing better comfort. The devices convert electrical energy into surface acoustic waves using a piezoelectric resonator. The resonator is sensitive to changes in strain, mass changes due to the absorption or loss of ions, and ultraviolet light, all of which can be used for different sensing measurements. —MSL
Single-crystalline gallium nitride nanomembranes enable high-sensitivity surface acoustic wave sensors for wireless electronic skin.
Headache, a highly prevalent neurological disorder, has consistently been linked with an elevated risk of dementia. However, most studies are focused on the relationship with migraine in limited age ...groups. Therefore, the objective of this research was to look at the link between various type of headaches and dementias based on longitudinal population-based data. Headache could be an independent predictor for subsequent dementia risk. Future studies should focus on clarifying pathogenic pathways and possible dementia-related preventive measures in headache populations.
Globally, soybean is a major protein and oil crop. Enhancing our understanding of the soybean domestication and improvement process helps boost genomics-assisted breeding efforts. Here we present a ...genome-wide variation map of 10.6 million single-nucleotide polymorphisms and 1.4 million indels for 781 soybean individuals which includes 418 domesticated (Glycine max), 345 wild (Glycine soja), and 18 natural hybrid (G. max/G. soja) accessions. We describe the enhanced detection of 183 domestication-selective sweeps and the patterns of putative deleterious mutations during domestication and improvement. This predominantly selfing species shows 7.1% reduction of overall deleterious mutations in domesticated soybean relative to wild soybean and a further 1.4% reduction from landrace to improved accessions. The detected domestication-selective sweeps also show reduced levels of deleterious alleles. Importantly, genotype imputation with this resource increases the mapping resolution of genome-wide association studies for seed protein and oil traits in a soybean diversity panel.
The hard X-ray free-electron laser at the Pohang Accelerator Laboratory (PAL-XFEL) in the Republic of Korea achieved saturation of a 0.144 nm free-electron laser beam on 27 November 2016, making it ...the third hard X-ray free-electron laser in the world, following the demonstrations of the Linac Coherent Light Source (LCLS) and the SPring-8 Angstrom Compact Free Electron Laser (SACLA). The use of electron-beam-based alignment incorporating undulator radiation spectrum analysis has allowed reliable operation of PAL-XFEL with unprecedented temporal stability and dispersion-free orbits. In particular, a timing jitter of just 20 fs for the free-electron laser photon beam is consistently achieved due to the use of a state-of-the-art design of the electron linear accelerator and electron-beam-based alignment. The low timing jitter of the electron beam makes it possible to observe Bi(111) phonon dynamics without the need for timing-jitter correction, indicating that PAL-XFEL will be an extremely useful tool for hard X-ray time-resolved experiments. The Pohang Accelerator Laboratory X-ray Free Electron Laser (PAL-XFEL) in South Korea has now entered operation with a timing jitter of just 20 fs.
A high‐performance, transparent, and extremely thin (<15 nm) hydrogen (H2) gas sensor is developed using 2D electron gas (2DEG) at the interface of an Al2O3/TiO2 thin film heterostructure grown by ...atomic layer deposition (ALD), without using an epitaxial layer or a single crystalline substrate. Palladium nanoparticles (≈2 nm in thickness) are used on the surface of the Al2O3/TiO2 thin film heterostructure to detect H2. This extremely thin gas sensor can be fabricated on general substrates such as a quartz, enabling its practical application. Interestingly, the electron density of the Al2O3/TiO2 thin film heterostructure can be tailored using ALD process temperature in contrast to 2DEG at the epitaxial interfaces of the oxide heterostructures such as LaAlO3/SrTiO3. This tunability provides the optimal electron density for H2 detection. The Pd/Al2O3/TiO2 sensor detects H2 gas quickly with a short response time of <30 s at 300 K which outperforms conventional H2 gas sensors, indicating that heating modules are not required for the rapid detection of H2. A wide bandgap (>3.2 eV) with the extremely thin film thickness allows for a transparent sensor (transmittance of 83% in the visible spectrum) and this fabrication scheme enables the development of flexible gas sensors.
A high‐performance, transparent, and extremely thin (≈15 nm) hydrogen (H2) gas sensor is developed using 2D electron gas at the interface of an Al2O3/TiO2 thin film heterostructure. This extremely thin gas sensor can be fabricated on general substrates such as a glass using atomic layer deposition, and this fabrication scheme enables the development of flexible gas sensors.
We investigated the functional outcomes regarding erectile function and urinary continence up to 5 years following radical prostatectomy （RP） in a cohort of Korean men. We retrospectively analyzed ...the clinicopathologic data of 85 Korean men who received open uni- or bilateral nerve-sparing RP for clinically localized prostate cancer and were followed up for at least 5 years postoperatively. From medical records, patients＇ status regarding urinary and erectile function at baseline and postoperative followups after RP was assessed. At 24 and 60 months after RP, proportions of subjects continent （no pads used） were 89.4% and 97.6%, respectively （P = 0.007）. Excluding subjects （n = 24） who preoperatively reported having severe erectile dysfunction or lacked relevant informations, proportions of subjects capable of having vaginal intercourse regardless of erectile aid usage were 47.5% and 37.7% at 24 and 60 months from RP, respectively （P = 0.022）. Patient＇s age at surgery （P = 0.047） and salvage radiation therapy （P = 0.026） were observed to be significant predictors of having erections sufficient for intercourse at 60 months from RP in multivariate analysis. Our results showed that while patients＇ postoperative status regarding urinary continence at 2 years from RP is generally maintained or improved at 5 year point, erectile function was observed to significantly declined from 2 years to 5 years following RP. Such decline in erectile function following RP may be more significant among men who were relatively older at surgery or those who received salvage therapy during postoperative follow-ups.
Epidemic outbreaks of multi-drug resistant (MDR) Acinetobacter baumannii (AB) in intensive care units (ICUs) are increasing. The incidence of MDR AB bacteremia, which develops as a result of ...colonization, is increasing through widespread dissemination of the pathogen, and further colonization. We sought to determine risk factors for MDR AB bacteremia in patients colonized with MDR AB in the ICU.
We conducted a retrospective, observational study of 200 patients colonized with MDR AB in the ICU at Severance Hospital, South Korea during the outbreak period between January 2008 and December 2009.
Of the 200 patients colonized with MDR AB, 108 developed MDR AB bacteremia, and 92 did not. APACHE II scores were higher in bacteremic than non-bacteremic patients at the time of ICU admission and colonization (24.0 vs. 21.6; P = 0.035, 22.9 vs. 16.8; P < 0.001, respectively). There was no difference between the two groups in the duration of time from ICU admission to colonization (7.1 vs. 7.2 days; P = 0.923), but the duration of time at risk was shorter in bacteremic patients (12.1 vs. 6.0 days; P = 0.016). A recent invasive procedure was a significant risk factor for development of bacteremia (odds ratio = 3.85; 95% CI 1.45-10.24; P = 0.007). Multivariate analysis indicated infection and respiratory failure at the time of ICU admission, maintenance of mechanical ventilation, maintenance of endotracheal tube instead of switching to a tracheostomy, recent central venous catheter insertion, bacteremia caused by other microorganism after colonization by MDR AB, and prior antimicrobial therapy, were significant risk factors for MDR AB bacteremia.
Patients in the ICU, colonized with MDR AB, should be considered for minimizing invasive procedures and early removal of the invasive devices to prevent development of MDR AB bacteremia.
We report on a molecularly tailored 1:1 donor–acceptor (D‐A) charge‐transfer (CT) cocrystal that manifests strongly red‐shifted CT luminescence characteristics, as well as noteworthy reconfigurable ...self‐assembling behaviors. A loosely packed molecular organization is obtained as a consequence of the noncentrosymmetric chemical structure of molecule A1, which gives rise to considerable free volume and weak intermolecular interactions. The stacking features of the CT complex result in an external stimuli‐responsive molecular stacking reorganization between the mixed and demixed phases of the D‐A pair. Accordingly, high‐contrast fluorescence switching (red↔blue) is realized on the basis of the strong alternation of the electronic properties between the mixed and demixed phases. A combination of structural, spectroscopic, and computational studies reveal the underlying mechanism of this stimuli‐responsive behavior.
To mix or not to mix: A donor–acceptor (D‐A) charge‐transfer (CT) crystalline film was designed to realize stimuli‐responsive reversible fluorescence switching media. Owing to the loosely packed CT state, reorganization between the red‐emissive mixed CT phase and blue‐emissive demixed self‐sorted phase can be demonstrated by external triggers such as solvent, thermal, and piezomechanical stimuli.
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