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Structural, Magnetic, and Transport Properties of MnNiGa Ribbon
No full textThe magnetic properties and the existence of spin reorientation have been systematically investigated in MnNiGa ribbons. The thermomagnetic curve reveals that as-spun and annealed ribbons undergo a two-step magnetic structural transformation and the magnetic properties of the annealed ribbons are improved. The splitting behaviour of zero-field-cooled and filed-cooled (ZFC-FC) curve shows that the ribbon has occurred a spin reorientation transformation. The ZFC and isothermal magnetization curves tested by changing the direction of the magnetic field illustrate the existence of magnetic anisotropy, and the direction of H// is easily magnetized. In the direction of easy magnetization, the value of magnetic entropy is about 1.54 J/kg K. The easy magnetization direction is proved to be in-plane by the decrease of the magnetic domain phase shift. It is clear that the magnetoresistance is negative in all temperature ranges and the nonlinear variation at low fields accounts for the presence of spin reorientation. The variation of Hall resistance curve in a low magnetic field reflects the existence of an abnormal Hall effect
Genetic Transformation of Plasmid DNA into Escherichia coli Using High Frequency Electromagnetic Energy
No full textWe present a novel technique of genetic transformation of bacterial cells mediated by high frequency electromagnetic energy (HF EME). Plasmid DNA, pGLO (5.4 kb), was successfully transformed into Escherichia coli JM109 cells after exposure to 18 GHz irradiation at a power density between 5.6 and 30 kW m-2 for 180 s at temperatures ranging from 30 to 40 °C. Transformed bacteria were identified by the expression of green fluorescent protein (GFP) using confocal scanning microscopy (CLSM) and flow cytometry (FC). Approximately 90.7% of HF EME treated viable E. coli cells exhibited uptake of the pGLO plasmid. The interaction of plasmid DNA with bacteria leading to transformation was confirmed by using cryogenic transmission electron microscopy (cryo-TEM). HF EME-induced plasmid DNA transformation was shown to be unique, highly efficient, and cost-effective. HF EME-induced genetic transformation is performed under physiologically friendly conditions in contrast to existing techniques that generate higher temperatures, leading to altered cellular integrity. This technique allows safe delivery of genetic material into bacterial cells, thus providing excellent prospects for applications in microbiome therapeutics and synthetic biology
Touch sensation requires the mechanically gated ion channel ELKIN1
No full textTouch perception is enabled by mechanically activated ion channels, the opening of which excites cutaneous sensory endings to initiate sensation. In this study, we identify ELKIN1 as an ion channel likely gated by mechanical force, necessary for normal touch sensitivity in mice. Touch insensitivity in Elkin1−/− mice was caused by a loss of mechanically activated currents (MA currents) in around half of all sensory neurons activated by light touch (low-threshold mechanoreceptors). Reintroduction of Elkin1 into sensory neurons from Elkin1−/− mice restored MA currents. Additionally, small interfering RNA–mediated knockdown of ELKIN1 from induced human sensory neurons substantially reduced indentation-induced MA currents, supporting a conserved role for ELKIN1 in human touch. Our data identify ELKIN1 as a core component of touch transduction in mice and potentially in humans
New visible-light-driven Bi2MoO6/Cs3Sb2Br9 heterostructure for selective photocatalytic oxidation of toluene to benzaldehyde
No full textHerein, new Bi2MoO6/Cs3Sb2Br9 heterostructure (BiMo/CSB) was investigated for the first time as a visible-light-driven photocatalyst for C(sp3)–H bond activation using molecular oxygen as a green oxidant and toluene as a model substrate. The optimized BiMo/CSB photocatalyst exhibited enhanced toluene oxidation activity (2,346 μmol g-1h−1), which was almost two- and five-fold that of pristine CSB (1,165 μmol g-1h−1) and BiMo (482 μmol g-1h−1), respectively. The improved photocatalytic performance was essentially attributed to the formation of staggered band energy lineup in the BiMo/CSB hybrid, which promoted S-scheme charge transfer across the BiMo/CSB heterointerface as supported by ultraviolet photoelectron spectroscopy (UPS), density functional theoretical (DFT), time-resolve photoluminescence (TRPL), and photoelectrochemical studies. Spin–trapping electron paramagnetic resonance (EPR) and radical scavenging studies revealed that photoinduced hole, molecular oxygen, and superoxide radical are key active species in this photocatalytic system. The developed BiMo/CSB catalyst provided good selectivity toward benzaldehyde product (94–98 %), presumably due to the inhibiting effect of benzyl alcohol on benzaldehyde oxidation. No significant change in structure and morphology was observed for the spent catalyst, however small negative shift of Sb 3d and Bi 4f binding energy was found suggesting partial reduction of Sb3+ and Bi3+. This work not only provides a new visible-light-driven photocatalyst for C(sp3)–H bond activation but also opens the doors for exploitation of the conversion and functionalization of this inert bond toward the production of high value-added organic chemicals
Progression of axonal excitability abnormalities with increasing clinical severity of diabetic peripheral neuropathy
No full textObjective: Diabetic peripheral neuropathy (DPN) is a frequent complication for persons with type 2 diabetes. Previous studies have failed to demonstrate any significant impact of treatment for DPN. The present study assessed the role of axonal ion channel dysfunction in DPN and explored the hypothesis that there may be a progressive change in ion channel abnormalities that varied with disease stage. Methods: Neurophysiological studies were conducted using axonal excitability techniques, a clinical method of assessing ion channel dysfunction. Studies were conducted in 178 persons with type 2 diabetes, with participants allocated into four groups according to clinical severity of neuropathy, assessed using the Total Neuropathy Grade. Results: Analysis of excitability data demonstrated a progressive and stepwise reduction in two parameters that are related to the activity of Kv1.1 channels, namely superexcitability and depolarizing threshold electrotonus at 10–20 ms (p < 0.001), and mathematical modelling of axonal excitability findings supported progressive upregulation of Kv1.1 conductances with increasing greater disease severity. Conclusion: The findings are consistent with a progressive upregulation of juxtaparanodal Kv1.1 conductances with increasing clinical severity of diabetic peripheral neuropathy. Significance: From a translational perspective, the study suggests that blockade of Kv1.1 channels using 4-aminopyridine derivatives such as fampridine may be a potential treatment for DPN
Australian population norms for health-related quality of life measured using the EQ-5D–5L, and relationships with sociodemographic characteristics
No full textBackground: Measuring health related quality-of-life (HRQoL) of the general population is essential to establish a reference for health outcome evaluations. This study sought to establish EQ-5D-5L population norms in Australia and to investigate the heterogeneity of HRQoL between sociodemographic variables. Methods: A cross-sectional study comprising of a representative sample of Australia’s general population (n = 9958) aged 18 or older. Recruitment quotas were set for the Australian census population by age, sex, state/territory of residence and rurality. Participants were recruited by Qualtrics through its database of over 800,000 registered panel members and asked to value their own state of health using the EQ-5D-5L domains and the EuroQol-Visual Analogue Scale (EQ-VAS). An Australian value set developed using Discreet Choice Experiment was used to calculate utility scores. Results: The estimated mean EQ-5D-5L index for Australia’s general population was 0.86 (standard deviation [SD] 0.19), and the EQ-VAS score was estimated as 73.2 (SD 21.7). 23.9% of the study population reported being in the best health state (11,111). Younger people, current smokers, people who are unemployed and people with more financial stress reported a lower EQ-5D-5L index score (p < 0.001). Residents in the major cities, inner regional and outer regional Australia reported higher health utility scores than those residing in remote and very remote Australia. Conclusions: This is the first Australian study to apply the EQ-5D-5L in a nationally representative sample. The EQ-5D-5L Australian population norms obtained can be used as reference scores for future population health evaluations and comparisons. The findings facilitate a national reference for clinical, economic, and policy decision-making processes and provide a fuller understanding of the Australian population’s HRQoL
Divergent Reactivity of 1,2,3-Benzotriazin-4(3H)-ones: Photocatalytic Synthesis of 3-Substituted Isoindolinones Achieved through a Nitrogen-Mediated Hydrogen Atom Shift
No full textA regioselective visible-light-mediated denitrogenative alkene insertion of 1,2,3-benzotriazin-4(3H)-ones was developed to access 3-substituted isoindolinones, an important structural motif present in many biologically active molecules and natural products. Notably, divergent reactivity was achieved by switching from reported nickel catalysis (where C3-substituted 3,4-dihydroisoquinolin-1(2H)-ones form) to photocatalysis, where photocatalytic denitrogenation and a subsequent nitrogen-mediated hydrogen atom shift lead to exclusive 3-substituted isoindolinone formation. The developed photocatalytic reaction is compatible with activated terminal alkenes and cyclic α,β-unsaturated esters and ketones, with wide functional group tolerance for N-substitution of the 1,2,3-benzotriazin-4(3H)-ones. The utility of this procedure is highlighted by a gram-scale synthesis and postsynthetic amidation. To understand the origin of this unique product selectivity, experimental and computational mechanistic studies were performed
In-sewer stability of 31 human health biomarkers and suitability for wastewater-based epidemiology
No full textMonitoring urinary markers of dietary, disease, and stress by wastewater-based epidemiology (WBE) is a promising tool to better understand population health and wellbeing. However, common urinary biomarkers are subject to degradation in sewer systems and their fates have to be assessed before they can be used in WBE. This study investigated the stability of 31 urinary biomarkers (12 food biomarkers, 8 vitamins, 9 oxidative stress biomarkers, and 1 histamine biomarker) in a laboratory sewer sediment reactor and evaluated their suitability for WBE, considering their detectability in real wastewater and in-sewer stability. These biomarkers showed various transformation patterns, among which 16 compounds had half-lives 500 h). Thirteen biomarkers showed potential for WBE because of their consistently measurable concentrations in untreated wastewater and sufficient in-sewer stability. Eighteen biomarkers were unsuitable due to their rapid in-sewer degradation and/or undetectable concentration levels in untreated wastewater using previous methods. Transformation rates of these biomarkers showed generally weak relationships with molecular properties but relatively higher correlations with biological activities in sewers. Overall, this study determined in-sewer stability of 31 health-related biomarkers through laboratory experiments, providing new findings to WBE for population health assessment
Systematic conservation planning for Antarctic research stations
No full textThe small ice-free areas of Antarctica are essential locations for both biodiversity and scientific research but are subject to considerable and expanding human impacts, resulting primarily from station-based research and support activities, and local tourism. Awareness by operators of the need to conserve natural values in and around station and visitor site footprints exists, but the cumulative nature of impacts often results in reactive rather than proactive management. With human activity spread across many isolated pockets of ice-free ground, the pathway to the greatest reduction of human impacts within this natural reserve is through better management of these areas, which are impacted the most. Using a case study of Australia's Casey Station, we found significant natural values persist within the immediate proximity (<10 m) of long-term station infrastructure, but encroachment by physical disturbance results in ongoing pressures. Active planning to better conserve such values would provide a direct opportunity to enhance protection of Antarctica's environment. Here we introduce an approach to systematic conservation planning, tailored to Antarctic research stations, to help managers improve the conservation of values surrounding their activity locations. Use of this approach provides a potential mechanism to balance the need for scientific access to the continent with international obligations to protect its environment. It may also facilitate the development of subordinate conservation tools, including management plans and natural capital accounting. By proactively minimising and containing their station footprints, national programs can also independently demonstrate their commitment to protecting Antarctica's environment
Achieving material diversity in wire arc additive manufacturing: Leaping from alloys to composites via wire innovation
No full textMulti-material components featuring high performance and design flexibility have attracted considerable attention, providing solutions to meet the performance demands of high-end equipment components. Achieving material diversity in additive manufacturing (AM) is a fundamental step towards manufacturing multi-material components. Wire arc additive manufacturing (WAAM), an important branch of AM technology, boasts notable advantages in the efficient and customized preparation of large-scale parts due to its high deposition efficiency and unrestricted forming size. However, achieving material diversity in WAAM, constrained by its reliance on wire-form raw materials, has emerged as a compelling challenge. Wire innovation, including multiple, stranded, and cored wires, have furnished solutions to this challenge. To this end, this review provides an overview of the current developments in WAAM via wire innovation and suggests future research directions, aiming to serve as a reference for the further advancement of WAAM. Initially, the article introduces several WAAM printing forms, their manufacturing features, printable materials and inherent manufacturing limitations, and the intermixing of metal constituents of WAAM, prior to highlighting the advantages and necessity of achieving material diversity. Subsequently, the exposition of multi-wire-arc AM demonstrates its utility in the preparation of binary or ternary alloys, inclusive of intermetallic compounds and functionally graded materials, responding adeptly to the deficiencies of conventional WAAM, which is limited to single-material printing. The merits and progression of stranded-wire-arc AM for high-entropy alloy production are synthesized and debated, especially given that creating components with multiple metal elements via multi-wire-arc AM customarily confronts the constraint of necessitating more intricate manufacturing equipment and processes. Further, the review explores the recently developed cored-wire-arc AM technology, which actualizes the manufacturing of composite materials, amalgamating metals and non-metals, to remedy the issues encountered with standard WAAM, incapable of realizing non-metallic material printing. Considering machine tools as an important means to achieve material diversity in WAAM, we expand on the current machine tool architecture and its corresponding design tools. Finally, the current research status on WAAM via wire innovation is summarized and potential future research directions are proposed