Zobrazení zdroje stránky Garzazachariassen8435

Although graphite has been used as anodes of lithium-ion batteries (LiBs) for 30 years, its unsatisfactory energy density makes it insufficient toward some new electronic products such as unmanned aerial vehicles. Herein, in situ synthesis of nano-GeP confined in nitrogen-doped carbon (GeP@NC) fibers was designed and performed via coaxial electrospinning followed by a phosphating process. This way ensured the paper-like GeP@NC-x electrode with high conductivity, high flexibility, and lightweight properties, which simultaneously solved the key scientific problems of difficulty in structural design and severe volume expansion of GeP. The inner diameter and wall thickness of the nanofibers can be effectively controlled by adjusting the size of electrospinning needles. It was suggested that the fibers not only effectively inhibited the growth of GeP, resulting in the synthesis of nano-GeP with size less than 50 nm, but also alleviated the volume expansion/agglomeration and improved the diffusion kinetics of Li+ in nano-GeP during cycling. The Li+ diffusion coefficient can be improved by reducing the inner diameter and wall thickness of the fibers. As a model system, the paper-like electrode (GeP@NC-2) with a fiber diameter of 280 nm and a wall thickness of 110 nm exhibited the best electrochemical performance. When applied as anodes in LiBs, it displayed a reversible capacity of 612 mAh g-1 at the 600th cycle at 1 A g-1, while GeP@NC-0 with a solid structure only delivered 239 mAh g-1. Furthermore, the GeP@NC-2 also exhibited good long-term cycling stability at 5 A g-1, and the capacity displayed a slight difference of 221.2 and 209.0 mAh g-1 in a voltage range of 0∼3 V and 0∼1.5 V, respectively. The well-defined synthetic approach combined with unique nanostructural design provided a meaningful reference for the rational design and development of next-generation flexible and high-performance LiB anodes.By virtue of their high uniformity and stability, metal oxide-based surface-enhanced Raman spectroscopy (SERS) substrates have attracted enormous attention for molecular trace detection. However, strategies for further enhancing the SERS sensitivity are still desired. Herein, MoOx/WOx nano-heterojunctions are constructed by mixing MoOx and WOx together (MoOx/WOx hybrid) with diverse weight ratios. Using a 532 nm laser as the excitation source and R6G as the Raman reporter, it is shown that the Raman signal intensity (for the peak @ 1360 cm-1) obtained on the optimal MoOx/WOx hybrid (MoOx/WOx = 11/3) is twice that observed on a pure MoOx or WOx substrate. Moreover, a limit of detection of 10-8 M and an enhancement factor of 108 are achieved. In the SERS enhancement mechanism investigation, it is revealed that MoOx and WOx form a staggered band structure. During the SERS measurement, electron-hole pairs are generated in the nano-heterojunction using the incident laser. They are then separated by the built-in potential with the electrons moving toward WOx. The accumulated electrons on WOx are further transferred to the R6G molecules through the coupling of orbitals. Consequently, the molecular polarizability is amplified, and SERS performance is enhanced. The abovementioned explanation is supported by the evidence that the contribution of the chemical enhancement mechanism in the optimal MoOx/WOx hybrid substrate is about 2.5 times or 5.9 times that in the pure WOx or MoOx substrate.This effort demonstrates the development of a novel, graphene oxide nanoscale thermite composite with thermally tunable microwave ignitability. A model thermite system containing nanoscale aluminum and nanoscale iron(II) oxide in a stoichiometric ratio (30/70 wt %) was combined with sheets of graphene oxide (GO) or reduced graphene oxide (rGO) using an immiscible two-fluid sonication and tape casting process. The samples were microwave irradiated within a single-mode resonant microwave cavity to determine the microwave ignition delay. Neat thermites were found to ignite after 4.34 s of microwave illumination, whereas 30 wt % rGO thermite composite ignition delay was an order of magnitude shorter (0.43 s). For most samples (4 of 6 trials), it was found that application of a 30 wt % GO coating inhibits microwave ignition of the thermite. Thermal treatment of the GO thermite composite led to switching of thermites from unignitable to ignitable with microwave field application as short as 0.24 s due to GO reduction. Optimum heat treatment time and GO content are explored with SEM, DSC/TGA-MS, Raman, and XPS deconvolution. This effort demonstrates the use of GO and rGO addition to achieve thermally switchable microwave ignitability to electromagnetically shield or enhance nanoscale energetic ignition by microwave energy.It is an important task to develop low-cost and anticoking catalysts for the propane dehydrogenation (PDH) reaction. In this work, the P element is introduced to the Ru-based catalyst to obtain Ru sites with a unique structure and the obtained RuxPy (x/y = 21, 11, 12) catalysts are then employed in PDH. Density functional theory (DFT) results show that the addition of P leads to the formation of separated Ru sites and the adjustment of the valance band state of Ru. The upward shift of the d-band center leads to a reduction of the reaction energy barrier for dehydrogenation of propane and an enhancement of catalytic activity. The analysis of the competition between propylene deep dehydrogenation and propylene desorption for each catalyst shows that desorption of propylene is preferred on the RuP(112) surface. Considering both catalytic activity and propylene selectivity, the RuP catalyst is potential for the propane dehydrogenation reaction. On the RuP surface, the PDH reaction proceeds by the dehydrogenation of the H atom on the methylene group (isopropyl pathway), thus restraining the deep dehydrogenation of propylene. The RuxPy catalysts are also synthesized in experiments, and PDH evaluation shows that the RuP structure is a remarkable PDH catalyst with a stable structure, anticoking ability, and low cost.Moisture capture coupled with photothermal regeneration provides an alternative and sustainable way to acquire fresh water. Composite moisture absorbents based on hygroscopic salts are environmentally friendly, economically feasible, and of high efficiency but suffer from the unavoidable desiccant leakage during absorption and evaporation-induced salt accumulation on material surfaces during desorption. In this study, we develop a superhydrophobic-hydrophilic-hydrophobic photothermal wood embedded with CaCl2 to promote the durability of the absorbents. The sandwich structure serves as a liquid/vapor gate allowing vapor transport but forbidding liquid permeation, enabling the condensation and evaporation within the wood. Beyond moisture harvesting, the sandwich-structured photothermal wood exhibits potential in indoor dehumidification by pumping the moisture through an absorption-desorption cycle.Preventive actions have reached a new height in the COVID-19 pandemic and since there is not a specific treatment yet, while the vaccines demonstrate their effectiveness and gradually are applied to the population, preventive measures are still recommended. Among these actions, occupational health faces challenges, since a significant part of the population is economically active and have had to suspend work, and in the current context, return-to-work measures have been implemented. The care and protection of healthcare workers is crucial, given that they are the specific population that takes care for patients infected with SARS-CoV-2 and this increases their exposure to the virus and expands their possibility of suffering from COVID-19, which must be recognized as an occupational disease which must be attended from the prevention of exposure to the care of sequelae and even compensation for death derived from this disease.<br /><br /> Several studies have evaluated the association between a history of type 2 diabetes (T2D) and risk of breast cancer (BC), with controversial results. However, information regarding the population-attributable risk percent (PAR%) remains scarce. Objective To estimate the association and the PAR% for BC and T2D, lifestyle and gynecologic factors in women in Mexico City.<br /><br /> This case-control study was performed from May-December 2020. Women &gt;40 years of age, from Mexico City, with a confirmed diagnosis for BC were included as cases. Controls were women with a BIRADS 1 or 2 mammography or an ultrasound clear of any BC suggestive findings.<br /><br /> A total of 134 cases and 134 controls were included. A higher risk for BC was identified among women who did not perform routine physical activity and those who had a history of hormonal contraceptive use &gt; 5 years. The use of hormone replacement therapy (HRT) was associated with an odds ratio (OR) of 5.0 (p = 0.22) in the first model. After adjustment, HRT was associated with an OR of 2.92 (p=0.492) in the second and an OR of 3.6 (p = 0.753) in the third model. T2D was associated with an OR of 1.04 (p = 0.96) in the first model; an OR of 0.65 (p = 0.65) in the second model and an OR of RMa 0.75(p = 0.79) for the third model.<br /><br /> In this case-control study, there was no significant association identified between a T2D diagnosis and BC.<br /><br />In this case-control study, there was no significant association identified between a T2D diagnosis and BC.<br /><br /> Acne vulgaris is among the most common dermatologic diagnoses observed, including skin color (SOC) populations. This project sought to help clarify the existing published data and provide consensus statements on acne presentation, prevention, treatment, and maintenance in SOC populations to help improve patient outcomes.<br /><br /> Six SOC dermatologists convened for a virtual meeting and used a modified Delphi process to address 1) Are there racial/ethnic differences in the clinical presentation and sequela of acne? 2) Are there racial/ethnic differences in the therapeutic endpoint of acne treatment and patient expectations? 3) Is there a need for specialized approaches to therapeutic options and skincare in acne patients with SOC? The results of a literature review and the outcome of discussions, coupled with the panel's expert opinion and experience, are intended for health care providers caring for acne patients and clinician-researchers.<br /><br /> Racial/ethnic differences in the clinical presentation, sequelae, and dezed approaches to therapeutic options and skincare in acne patients with SOC. OTC skincare products are recommended before and during prescription therapy and as part of a maintenance regimen. J Drugs Dermatol. 2021;20(7)716-725. doi10.36849/JDD.6169 THIS ARTICLE HAD BEEN MADE AVAILABLE FREE OF CHARGE. PLEASE SCROLL DOWN TO ACCESS THE FULL TEXT OF THIS ARTICLE WITHOUT LOGGING IN. NO PURCHASE NECESSARY. PLEASE CONTACT THE PUBLISHER WITH ANY QUESTIONS.<br /><br /> Few studies have examined topical psoriasis therapies in patients with skin of color. [https://www.selleckchem.com/EGFR(HER).html EGFR inhibitor] Fixed-combination halobetasol propionate (0.01%) and tazarotene (0.045%) lotion (HP/TAZ) was investigated in two phase 3, multicenter, double-blind, vehicle-controlled trials (NCT02462070; NCT02462122). This post hoc analysis evaluated HP/TAZ in subgroups of non-White and White participants, including Hispanic/Latino participants, from these trials.<br /><br /> Adult participants were randomized (21) to receive HP/TAZ or vehicle lotion once daily for 8 weeks. Data were pooled and analyzed in non-mutually exclusive subgroups of self-identified non-White or White and Hispanic/Latino participants. Efficacy assessments included treatment success (&amp;ge;2-grade improvement from baseline in investigator&amp;rsquo;s global assessment [IGA] and score of clear/almost clear), reduction from baseline in affected body surface area (BSA), and reduction in mean IGA &amp;times; BSA. Safety was evaluated via treatment-emergent adverse events (TEAEs).