In this study, we evaluated the efficacy of hydroxychloroquine (HCQ) against coronavirus disease 2019 (COVID-19) via a randomized controlled trial (RCT) and a retrospective study.
Subjects admitted ...to 11 designated public hospitals in Taiwan between April 1 and May 31, 2020, with COVID-19 diagnosis confirmed by pharyngeal real-time RT-PCR for SARS-CoV-2, were randomized at a 2:1 ratio and stratified by mild or moderate illness. HCQ (400 mg twice for 1 d or HCQ 200 mg twice daily for 6 days) was administered. Both the study and control group received standard of care (SOC). Pharyngeal swabs and sputum were collected every other day. The proportion and time to negative viral PCR were assessed on day 14. In the retrospective study, medical records were reviewed for patients admitted before March 31, 2020.
There were 33 and 37 cases in the RCT and retrospective study, respectively. In the RCT, the median times to negative rRT-PCR from randomization to hospital day 14 were 5 days (95% CI; 1, 9 days) and 10 days (95% CI; 2, 12 days) for the HCQ and SOC groups, respectively (p = 0.40). On day 14, 81.0% (17/21) and 75.0% (9/12) of the subjects in the HCQ and SOC groups, respectively, had undetected virus (p = 0.36). In the retrospective study, 12 (42.9%) in the HCQ group and 5 (55.6%) in the control group had negative rRT-PCR results on hospital day 14 (p = 0.70).
Neither study demonstrated that HCQ shortened viral shedding in mild to moderate COVID-19 subjects.
Mechanical failure of π‐conjugated polymer thin films is unavoidable under cyclic loading conditions, due to intrinsic defects and poor resistance to crack propagation. Here, the first tear‐resistant ...and room‐temperature self‐healable semiconducting composite is presented, consisting of conjugated polymers and butyl rubber elastomers. This new composite displays both a record‐low elastic modulus (<1 MPa) and ultrahigh deformability with fracture strain above 800%. More importantly, failure behavior is not sensitive to precut notches under deformation. Autonomous self‐healing at room temperature, both mechanical and electronic, is demonstrated through the physical contact of two separate films. The composite film also shows device stability in the ambient environment over 5 months due to much‐improved barrier property to both oxygen and water. Butyl rubber is broadly applicable to various p‐type and n‐type semiconducting polymers for fabricating self‐healable electronics to provide new resilient electronics that mimic the tear resistance and healable property of human skin.
A mechanically durable and electronically stable semiconducting composite is engineered by introducing a blend of donor–acceptor polymer and butyl rubber elastomer. The composite exhibits ultralow modulus, ultrahigh deformability, tear resistance, and self‐healing performance, as well as ambient stable device stability. This method is widely applicable to different semiconducting polymers.
Donor–acceptor (D–A) type semiconducting polymers have shown great potential for the application of deformable and stretchable electronics in recent decades. However, due to their heterogeneous ...structure with rigid backbones and long solubilizing side chains, the fundamental understanding of their molecular picture upon mechanical deformation still lacks investigation. Here, the molecular orientation of diketopyrrolopyrrole (DPP)‐based D–A polymer thin films is probed under tensile deformation via both experimental measurements and molecular modeling. The detailed morphological analysis demonstrates highly aligned polymer crystallites upon deformation, while the degree of backbone alignment is limited within the crystalline domain. Besides, the aromatic ring on polymer backbones rotates parallel to the strain direction despite the relatively low overall chain anisotropy. The effect of side‐chain length on the DPP chain alignment is observed to be less noticeable. These observations are distinct from traditional linear‐chain semicrystalline polymers like polyethylene due to distinct characteristics of backbone/side‐chain combination and the crystallographic characteristics in DPP polymers. Furthermore, a stable and isotropic charge carrier mobility is obtained from fabricated organic field‐effect transistors. This study deconvolutes the alignment of different components within the thin‐film microstructure and highlights that crystallite rotation and chain slippage are the primary deformation mechanisms for semiconducting polymers.
In this study, the chain alignment mechanism of semiconducting polymers under tensile deformation is carefully investigated. The thin‐film mechanical behavior is determined by the film‐on‐water tensile tester, while multimodal characterization methods are applied to capture the microstructural evolution, including hard, tender, soft X‐ray, UV–vis, and molecular simulation. Both crystallite rotation and chain sliding are determined to be the primary mechanisms during deformation.
In this paper, we prove the energy conservation for the weak solutions of the compressible Navier–Stokes equations for any time
t
> 0, under certain conditions. The results hold for the renormalized ...solutions of the equations with constant viscosities, as well as the weak solutions of the equations with degenerate viscosity. Our conditions do not depend on the dimensions. The energy may be conserved on the vacuum for the compressible Navier–Stokes equations with constant viscosities. Our results are the first ones on energy conservation for the weak solutions of the compressible Navier–Stokes equations.
The electrosynthesis from 5‐hydroxymethylfurfural (HMF) is considered a green strategy to achieve biomass‐derived high‐value chemicals. As the molecular structure of HMF is relatively complicated, ...understanding the HMF adsorption/catalysis behavior on electrocatalysts is vital for biomass‐based electrosynthesis. The electrocatalysis behavior can be modulated by tuning the adsorption energy of the reactive molecules. In this work, the HMF adsorption behavior on spinel oxide, Co3O4 is discovered. Correspondingly, the adsorption energy of HMF on Co3O4 is successfully tuned by decorating with single‐atom Ir. It is observed that compared with bare Co3O4, single‐atom‐Ir‐loaded Co3O4 (Ir‐Co3O4) can enhance adsorption with the CC groups of HMF. The synergetic adsorption can enhance the overall conversion of HMF on electrocatalysts. With the modulated HMF adsorption, the as‐designed Ir‐Co3O4 exhibits a record performance (with an onset potential of 1.15 VRHE) for the electrosynthesis from HMF.
Single atoms of Ir are anchored on Co3O4 for efficient electro‐oxidation of 5‐hydroxymethylfurfural (HMF). It is found that an isolated Ir atom can optimize the adsorption configuration of HMF molecules on catalysts and accelerate HMF oxidation.
The rapid progress of proton exchange membrane fuel cells (PEMFCs) and alkaline exchange membrane fuel cells (AMFCs) has boosted the hydrogen economy concept via diverse energy applications in the ...past decades. For a holistic understanding of the development status of PEMFCs and AMFCs, recent advancements in electrocatalyst design and catalyst layer optimization, along with cell performance in terms of activity and durability in PEMFCs and AMFCs, are summarized here. The activity, stability, and fuel cell performance of different types of electrocatalysts for both oxygen reduction reaction and hydrogen oxidation reaction are discussed and compared. Research directions on the further development of active, stable, and low‐cost electrocatalysts to meet the ultimate commercialization of PEMFCs and AMFCs are also discussed.
The development of fuel cells is of great significance for achieving a sustainable society. Recent progress in cathodic electrocatalysts for proton exchange membrane fuel cells and anodic and cathodic electrocatalysts for alkaline exchange membrane fuel cells is summarized. The rational design strategies, structure evolution, activities, fuel cell performance, and durability of noble‐metal‐ and non‐noble‐metal‐based electrocatalysts are discussed.
An outbreak of coronavirus disease 2019 (COVID‐19) occurred in Wuhan and it has rapidly spread to almost all parts of the world. For coronaviruses, RNA‐dependent RNA polymerase (RdRp) is an important ...protease that catalyzes the replication of RNA from RNA template and is an attractive therapeutic target. In this study, we screened these chemical structures from traditional Chinese medicinal compounds proven to show antiviral activity in severe acute respiratory syndrome coronavirus (SARS‐CoV) and the similar chemical structures through a molecular docking study to target RdRp of SARS‐CoV‐2, SARS‐CoV, and Middle East respiratory syndrome coronavirus (MERS‐CoV). We found that theaflavin has a lower idock score in the catalytic pocket of RdRp in SARS‐CoV‐2 (−9.11 kcal/mol), SARS‐CoV (−8.03 kcal/mol), and MERS‐CoV (−8.26 kcal/mol) from idock. To confirm the result, we discovered that theaflavin has lower binding energy of −8.8 kcal/mol when it docks in the catalytic pocket of SARS‐CoV‐2 RdRp by using the Blind Docking server. Regarding contact modes, hydrophobic interactions contribute significantly in binding and additional hydrogen bonds were found between theaflavin and RdRp. Moreover, one π‐cation interaction was formed between theaflavin and Arg553 from the Blind Docking server. Our results suggest that theaflavin could be a potential SARS‐CoV‐2 RdRp inhibitor for further study.
Highlights
Theaflavin has a lower idock score in the catalytic pocket of RdRp in SARS‐CoV‐2, SARS‐CoV and MERS‐CoV from idock.
Theaflavin has a lowest binding energy when it docks in the catalytic pocket of SARS‐CoV‐2 RdRp.
Theaflavin could be potential SARS‐CoV‐2 RdRp inhibitor.
A biolaser utilizes biological materials as part of its gain medium and/or part of its cavity. It can also be a micro‐ or nanosized laser embedded/integrated within biological materials. The biolaser ...employs lasing emission rather than regular fluorescence as the sensing signal and therefore has a number of unique advantages that can be explored for broad applications in biosensing, labeling, tracking, contrast agent development, and bioimaging. This article reports on the progress in biolasers with focus on the work done in the past five years. In the end, the possible future directions of the biolaser are discussed.
Biolasers and their applications in biology and biomedicine are reviewed in this progress report. The biolaser employs lasing emission rather than regular fluorescence as the sensing signal and therefore has a number of unique advantages that can be explored for broad applications in biosensing, labeling, tracking, contrast agent development, and bioimaging.
Photothermal cancer therapy using near-infrared (NIR) laser radiation is an emerging treatment. In the NIR region, two biological transparency windows are located in 650-950 nm (first NIR window) and ...1000-1350 nm (second NIR window) with optimal tissue transmission obtained from low scattering and energy absorption, thus providing maximum radiation penetration through tissue and minimizing autofluorescence. To date, intensive effort has resulted in the generation of various methods that can be used to shift the absorbance of nanomaterials to the 650-950 nm NIR regions for studying photoinduced therapy. However, NIR light absorbers smaller than 100 nm in the second NIR region have been scant. We report that a Au nanorod (NR) can be designed with a rod-in-shell (rattle-like) structure smaller than 100 nm that is tailored to be responsive to the first and second NIR windows, in which we can perform hyperthermia-based therapy. In vitro performance clearly displays high efficacy in the NIR photothermal destruction of cancer cells, showing large cell-damaged area beyond the laser-irradiated area. This marked phenomenon has made the rod-in-shell structure a promising hyperthermia agent for the in vivo photothermal ablation of solid tumors when activated using a continuous-wave 808 m (first NIR window) or a 1064 nm (second NIR window) diode laser. We tailored the UV-vis-NIR spectrum of the rod-in-shell structure by changing the gap distance between the Au NR core and the AuAg nanoshell, to evaluate the therapeutic effect of using a 1064 nm diode laser. Regarding the first NIR window with the use of an 808 nm diode laser, rod-in-shell particles exhibit a more effective anticancer efficacy in the laser ablation of solid tumors compared to Au NRs.
Combining noble metals with nonnoble metals is an attractive strategy to balance the activity and cost of electrocatalysts. However, a guiding principle for selecting suitable nonnoble metals is ...still lacking. Herein, a thorough mechanistic study on the platform oxygen evolution reaction (OER) electrocatalyst of Ir@Co3O4 to deeply understand the synergy between Ir and Co3O4 for the boosted OER has been carried out. It is demonstrated that the pseudocapacitive feature of Co3O4 plays a key role in accumulating sufficient positive charge Q, while the Ir sites are responsible for achieving a high reaction order (β), synergistically contributing to the high OER activity of Ir@Co3O4 through the rate law equation. Specifically, Ir@Co3O4 displays a low overpotential of 280 mV at 10 mA cm−2 with a small Ir loading of 1.4 wt%. Ir@Co3O4 is further applied to Zn‐air batteries, which enables a low charging potential and thus alleviates the oxidative corrosion of the air electrode, leading to improved cycle stability of 210 h at 20 mA cm−2. This work demonstrates that anchoring active noble metal sites (for high β) on pseudocapacitive supports (for high Q) is highly favorable to the OER process, providing a clear guidance for boosting the utilization of noble metals in electrocatalysis.
Ultra‐low loading Ir (1.4 wt%) is anchored on Co3O4 for oxygen evolution reaction (OER). The pseudocapacitive Co3O4 helps accumulate the positive charge Q, while the Ir sites help achieve a high reaction order (β). Anchoring the ultra‐low loading noble catalyst on the pseudocapacitive non‐noble catalyst is a promising strategy for high‐performance low‐cost catalyst development.
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