Francislong4971
A heteroleptic amidoalane precursor is presented as a more suitably designed candidate to replace trimethylaluminum (TMA) for atomic layer deposition of aluminum nitride (AlN). The lack of C-Al bonds and the strongly reducing hydride ligands in [AlH2(NMe2)]3 (1) were specifically chosen to limit impurities in target aluminum nitride (AlN) films. Compound 1 is made in a high yield, scalable synthesis involving lithium aluminum hydride and dimethylammonium chloride. It has a vapor pressure of 1 Torr at 40 °C and evaporates with negligible residual mass in thermogravimetric experiments. Ammonia (NH3) plasma and 1 in an atomic layer deposition (ALD) process produced crystalline AlN films above 200 °C with an AlN ratio of 1.04. Carbon and oxygen impurities in resultant AlN films were reduced to less then 1% and less then 2%, respectively. By using a precursor with a rational and advantageous design, we can improve the material quality of AlN films compared to those deposited using the industrial standard trimethylaluminum and could reduce material cost by up to 2 orders of magnitude.The United States Centers for Disease Control and Prevention and World Health Organization recognize that wearing cloth face coverings can slow the transmission of respiratory diseases via source control. Adding a partial layer of material with a high filtration efficiency (FE, e.g., polypropylene sheets that meet the HEPA standard) as an insert can potentially provide additional personal protection; however, data on the necessary areal coverage are sparse. The relationship between insert area ratio (IAR) relative to fabric area, FE, differential pressure (ΔP, a surrogate for breathability), and quality factor (QF, a ratio including FE and ΔP) utilizing two fabrics (rayon and 100% cotton lightweight flannel) and three insert materials (HEPA vacuum bag, sterilization wrap and paper coffee filter) was investigated. The effect of inserts on particle flows mimicking human exhalation is semiquantitatively and qualitatively examined using flow visualization techniques. The following was found (1) The relationship between FE, ΔP, and QF is complex, and a trade-off exists between personal protection from filtration during inhalation and source control from leakage during exhalation; (2) FE and ΔP of the composite covering increase with IAR, and the rate is dependent upon insert type; (3) improvements (decrements) in the QF of the composite assemblage require inserts with a higher (lower) QF than the fabric and larger differences yield greater gains (losses); (4) the increased ΔP from an insert results in increased leakage during exhalation; (5) to minimize leaks, ΔP must be as low as possible; and (6) small relative areas not covered by an insert (i.e., IAR slightly smaller than 1) strongly deteriorate the benefits of an insert similar to small leaks in a covering.Much effort has been devoted to developing electrocatalysts applicable to anion exchange membrane water electrolyzers (AEMWEs). Among many candidates for oxygen evolution reaction, NiFe-layered double hydroxide (LDH)-based electrocatalysts show the highest activity in an alkaline medium. Unfortunately, the poor electrical conductivity of NiFe-LDH limits its potential as an electrocatalyst, which was often solved by hybridization with conductive carbonaceous materials. However, we find that using carbonaceous materials for anodes has detrimental effects on the stability of AEMWEs at industrially relevant current densities. In this work, a facile monolayer structuring is suggested to overcome low electrical conductivity and improve mass transport without using carbonaceous materials. The monolayer NiFe-LDH deposited on Ni foam showed much better AEMWE performance than conventional bulk NiFe-LDH due to better electrical conductivity and higher hydrophilicity. A high energy conversion efficiency of 72.6% and outstanding stability at a current density of 1 A cm-2 over 50 h could be achieved without carbonaceous material. This work highlights electrical conductivity and hydrophilicity of catalysts in membrane-electrode-assembly as key factors for high-performance AEMWEs.Films with the capacity for photoluminescence and haze, which can convert UV to visible light and enhance light management, are of great importance for optoelectronic devices. Here, taking advantage of the inherent fluorescence and self-assembly properties of lignin, we have developed a sustainable lignin-derived multifunctional dopant (L-MS-NPs) for fabricating optical films with haze, fluorescence, and room-temperature phosphorescence (RTP) together with poly(vinyl alcohol) (PVA). The optical films are used to improve the light-harvesting efficiency of solar cells. Specifically, attributed to the robust morphology in the film matrix, L-MS-NPs cause a rough morphology in the surface of an L-MS-NPs/PVA composite film, which eventually triggers the great optical haze. Additionally, L-MS-NPs inherit fluorescence properties from lignin and show fluorescence emission when embed in the film matrix. Moreover, the PVA film matrix can stabilize the excited triplet state, which finally induces RTP of L-MS-NPs. The combined haze, fluorescence, and RTP properties of the L-MS-NPs/PVA composite film enhances the power conversion efficiency (PCE) of dye-sensitized solar cells from ∼3.9 to ∼4.1%.Biomedical diagnostics based on microfluidic devices have the potential to significantly benefit human health; however, the manufacturing of microfluidic devices is a key limitation to their widespread adoption. Outbreaks of infectious disease continue to demonstrate the need for simple, sensitive, and translatable tests for point-of-care use. Additive manufacturing (AM) is an attractive alternative to conventional approaches for microfluidic device manufacturing based on injection molding; however, there is a need for development and validation of new AM process capabilities and materials that are compatible with microfluidic diagnostics. In this paper, we demonstrate the development and characterization of AM cartridges using continuous liquid interface production (CLIP) and investigate process characteristics and capabilities of the AM microfluidic device manufacturing. We find that CLIP accurately produces microfluidic channels as small as 400 μm and that it is possible to routinely produce fluid channels as small as 100 μm with high repeatability. We also developed a loop-mediated isothermal amplification (LAMP) assay for detection of E. coli from whole blood directly on the CLIP-based AM microfluidic cartridges, with a 50 cfu/μL limit of detection, validating the use of CLIP processes and materials for pathogen detection. The portable diagnostic platform presented in this paper could be used to investigate and validate other AM processes for microfluidic diagnostics and could be an important component of scaling up the diagnostics for current and future infectious diseases and pandemics.In 1980, Roger Tsien published a paper, in this journal [Tsien, R. Y. (1980) Biochemistry, 19 (11), 2396], titled "New calcium indicators and buffers with high selectivity against magnesium and protons design, synthesis, and properties of prototype structures". These new buffers included 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, or BAPTA, which is still widely used today. And so, the world was set alight with new ways in which to visualize Ca2+. The ability to watch fluctuations in intracellular Ca2+ revolutionized the life sciences, although the fluorescent indicators used today, particularly in neurobiology, no longer rely exclusively on BAPTA but on genetically encoded fluorescent Ca2+ indicators. In this Perspective, we reflect on the origins of Ca2+ imaging with a special focus on the contributions made by Roger Tsien, from the early concept of selective Ca2+ binding described in Biochemistry to optical Ca2+ indicators based on chemically synthesized fluorophores to genetically encoded fluorescent Ca2+ indicators.Because of the favorable mass transport and increased available active sites, the rational design and preparation of porous carbon structures are essential but still challenging. Herein, a novel and facile supramolecular anchoring strategy was developed to achieve the embedding of ruthenium (Ru) nanoparticles in N-doped mesoporous carbon nanospheres through pyrolyzing the precursor formed by coordination assembly between metal ions and zinc gluconate (G(Zn)). Featuring rich hydroxyl groups, the G(Zn) can effectively chelate Ru3+ via metal-oxygen bonds to form 3D supramolecular nanospheres, and meanwhile, mesopores in carbon nanospheres were expanded after subsequent pyrolysis thanks to the volatilization of zincic species at high temperature. As a demonstration, the best-performing catalyst displayed extraordinary activity for the hydrogen evolution reaction (HER) with a small overpotential of 43 mV versus reversible hydrogen electrode (vs RHE) at 10 mA/cm2 and a Tafel slope of 39 mV/dec, which was superior to that of commercial Pt/C in alkaline medium. Theoretical calculations revealed that the catalytic activity was significantly promoted by the strong electronic coupling between Ru nanoparticles and N-doped porous carbon, which increased the electron transfer capability and facilitated the adsorption and dissociation of H2O to realize an efficient HER.
Bone stress injury (BSI) in youth runners are clinically important during times of skeletal growth and are not well studied.
Evaluate the prevalence, anatomical distribution, and factors associated with running-related BSI in boy and girl middle school runners.
Retrospective cross-sectional study.
Online survey distributed to middle school runners.
Survey evaluated BSI history, age, grade, height, weight, eating behaviors, menstrual function, exercise training, and other health characteristics.
Prevalence and characteristics associated with history of BSI, stratified by cortical-rich (eg, tibia) and trabecular-rich (pelvis and femoral neck) locations.
2107 runners (n=1250 boys, n=857 girls), age 13.2 ± 0.9y.
One hundred-five (4.7%) runners reported a history of 132 BSIs, with higher prevalence in girls than boys (6.7% vs 3.8%, P=0.004). The most common location was the tibia (n=51). Most trabecular-rich BSIs (n=16, 94% total) were sustained by girls (pelvis n=6; femoral neck n=6; sacrum n=4). h BSI in this population. This article is protected by copyright. All rights reserved.
While family history of osteoporosis and prior fracture (non-BSI) were most strongly related to BSI in the youth runners, behaviors contributing to an energy deficit, such as eating disorder and consuming less then 3 meals daily, also emerged as independent factors associated with BSI. While cross-sectional design limits determining causality, our findings suggest promoting optimal skeletal health through nutrition and participation in other sports including soccer and basketball may address factors associated with BSI in this population. This article is protected by copyright. All rights reserved.
Increasing studies have reported that oncogenes regulate components of the immune system, suggesting that this is a mechanism for tumorigenesis. Aurora kinase A (AURKA), a serine/threonine kinase, is involved in cell mitosis and is essential for tumor cell proliferation, metastasis, and drug resistance. However, the mechanism by which AURKA is involved in immune response regulation is unclear. Therefore, this study aimed to investigate the role of AURKA in immune regulation in triple-negative breast cancer (TNBC).
Peripheral blood mononuclear cells (PBMCs) were co-cultured with TNBC cells. The xCELLigence Real-Time Cell Analyzer-MP system was used to detect the killing efficiency of immune cells on TNBC cells. FDA approved Drug Library The expression of immune effector molecules was tested by quantitative real-time polymerase chain reaction (qRT-PCR) to evaluate immune function. Furthermore, to validate AURKA-regulated immune response in vivo, 4T1 murine breast cancer cell line with AURKA overexpression or downregulation was engrafted into BALB/c mice.