Monolithic Polyepoxide Membranes for Nanofiltration Applications and Sustainable Membrane Manufacture.

The present work details the development of carbon fiber-reinforced epoxy membranes with excellent rejection of small-molecule dyes. It is a proof-of-concept for a more sustainable membrane design incorporating carbon fibers, and their recycling and reuse. 4,4'-methylenebis(cyclohexylamine) (MBCHA) polymerized with either bisphenol-A-diglycidyl ether (BADGE) or tetraphenolethane tetraglycidylether (EPON Resin 1031) in polyethylene glycol (PEG) were used to make monolithic membranes reinforced by nonwoven carbon fibers.

Reprecipitation: A Rapid Synthesis of Micro-Sized Silicon-Graphene Composites for Long-lasting Lithium-Ion Batteries.

Silicon microparticles (SiMPs) have gained significant attention as a lithium-ion battery anode material due to their 10 times higher theoretical capacity compared to conventional graphite anodes as well as their much lower production cost than silicon nanoparticles (SiNPs). However, SiMPs have suffered from poorer cycle life relative to SiNPs because their larger size makes them more susceptible to volume changes during charging and discharging. Creating a wrapping structure in which SiMPs are enveloped by carbon layers has proven to be an effective strategy to significantly improve the cycling performance of SiMPs.

Rotavirus core shell protein sites that regulate intra-particle polymerase activity.

Rotaviruses are important causes of severe gastroenteritis in young children. A characteristic feature of rotaviruses is that they copy ribonucleic acid (RNA) inside of the viral particle. In fact, the viral polymerase (VP1) only functions when it is connected to the viral inner core shell protein (VP2).

In vitro particle-associated uridyltransferase activity of the rotavirus VP1 polymerase.

Rotaviruses are 11-segmented, double-stranded RNA (dsRNA) viruses with a unique intra-particle RNA synthesis mechanism. During genome replication, the RNA-dependent RNA polymerase (VP1) performs minus-strand RNA (-ssRNA) synthesis on positive-strand RNA (+ssRNA) templates to create dsRNA segments. Recombinant VP1 catalyzes -ssRNA synthesis using substrate NTPs in vitro, but only when the VP2 core shell protein or virus-like particles made of VP2 and VP6 (2/6-VLPs) are included in the reaction.

A Readily Scalable, Clinically Demonstrated, Antibiofouling Zwitterionic Surface Treatment for Implantable Medical Devices.

Unlike growth on tissue, microbes can grow freely on implantable devices with minimal immune system intervention and often form resilient biofilms that continuously pump out pathogenic cells. The efficacy of antibiotics used to treat infection is declining due to increased rates of pathogenic resistance. A simple, one-step zwitterionic surface modification is developed to significantly reduce protein and microbial adhesion to synthetic materials and demonstrate the successful modification of several clinically relevant materials, including recalcitrant materials such as elastomeric polydimethylsiloxane.

Reverse genetic engineering of simian rotaviruses with temperature-sensitive lesions in VP1, VP2, and VP6.

Rotaviruses are 11-segmented double-stranded RNA viruses and important causes of acute gastroenteritis in young children. To investigate the functions of specific viral proteins during the rotavirus lifecycle, temperature-sensitive (ts) mutants were previously created using a cultivatable simian strain (SA11) and chemical mutagenesis. These ts SA11 mutants replicate more efficiently at the permissive temperature of 31 °C than at the non-permissive temperature of 39 °C.

Social media and COVID-19: Can social distancing be quantified without measuring human movements?

The COVID-19 outbreak has posed significant threats to international health and the economy. In the absence of treatment for this virus, public health officials asked the public to practice social distancing to reduce the number of physical contacts. However, quantifying social distancing is a challenging task and current methods are based on human movements.

Social media and COVID-19: Characterizing anti-quarantine comments on Twitter.

Social media has become a mainstream channel of communication during the COVID-19 pandemic. While some studies have been developed on investigating public opinion on social media data regarding COVID-19 pandemic, there is no study analyzing anti-quarantine comments on social media. This study has collected and analyzed near 80,000 tweets to understand anti-quarantine social comments.

Ultrapermeable Organic Solvent Nanofiltration Membranes with Precisely Tailored Support Layers Fabricated Using Thin-Film Liftoff.

Thin-film composite (TFC) membranes are favored for precise molecular sieving in liquid-phase separations; they possess high permeability due to the minimal thickness of the active layer and the high porosity of the support layer. However, current TFC membrane fabrication techniques are limited by the available materials for the selective layer and do not demonstrate the level of structural control needed to substantially advance organic solvent nanofiltration (OSN) membrane technology. In this work, we employ the newly developed thin-film lift-off (T-FLO) technique to fabricate polybenzimidazole (PBI) TFC membranes with porous support layers uniquely tailored to OSN.

Can Emergency Physicians Accurately Rule Out a Central Cause of Vertigo Using the HINTS Examination? A Systematic Review and Meta-analysis.

Introduction: Dizziness is a common complaint presented in the emergency department (ED). A subset of these patients will present with acute vestibular syndrome (AVS). AVS is a clinical syndrome defined by the presence of vertigo, nystagmus, head motion intolerance, ataxia, and nausea/vomiting.

Nanostructured Graphene Oxide Composite Membranes with Ultrapermeability and Mechanical Robustness.

Graphene oxide (GO) membranes have great potential for separation applications due to their low-friction water permeation combined with unique molecular sieving ability. However, the practical use of deposited GO membranes is limited by the inferior mechanical robustness of the membrane composite structure derived from conventional deposition methods. Here, we report a nanostructured GO membrane that possesses great permeability and mechanical robustness.

Laser-Assisted Lattice Recovery of Graphene by Carbon Nanodot Incorporation.

Producing highly oriented graphene is a major challenge that constrains graphene from fulfilling its full potential in technological applications. The exciting properties of graphene are impeded in practical bulk materials due to lattice imperfections that hinder charge mobility. A simple method to improve the structural integrity of graphene by utilizing laser irradiation on a composite of carbon nanodots (CNDs) and 3D graphene is presented.

Next-Generation Asymmetric Membranes Using Thin-Film Liftoff.

For the past 30 years, thin-film membrane composites have been the state-of-the-art technology for reverse osmosis, nanofiltration, ultrafiltration, and gas separation. However, traditional membrane casting techniques, such as phase inversion and interfacial polymerization, limit the types of material that are used for the membrane separation layer. Here, we describe a novel thin-film liftoff (T-FLO) technique that enables the fabrication of thin-film composite membranes with new materials for desalination, organic solvent nanofiltration, and gas separation.

Self-Assembled Functionally Graded Graphene Films with Tunable Compositions and Their Applications in Transient Electronics and Actuation.

The facile fabrication of functionally graded all-graphene films using a single-step casting process is reported. The films consist of a self-assembled graphene oxide (GO) precursor that can be reduced to different levels on an active metal substrate. Control of processing conditions such as the underlying substrate metal and the film-drying environment results in an ability to tailor the internal architecture of the films as well as to functionally grade the reduction of GO.

Superhard Tungsten Diboride-Based Solid Solutions.

Solid solutions of tungsten diboride (WB) with increasing substitution of tungsten (W) by tantalum (Ta) and niobium (Nb)-ranging from 0 to 50 at. % on a metals basis-were synthesized through resistive arc melting. Samples were characterized using a combination of powder X-ray diffraction (PXRD) for phase identification, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy for elemental composition, Vickers microindentation for hardness measurements, and thermogravimetric analysis for thermal stability.

Carbon Nanodots as Feedstock for a Uniform Hematite-Graphene Nanocomposite.

High degrees of dispersion are a prerequisite for functional composite materials for applications in electronics such as sensors, charge and data storage, and catalysis. The use of small precursor materials can be a decisive factor in achieving a high degree of dispersion. In this study, carbon nanodots are used to fabricate a homogeneous, finely dispersed Fe O -graphene composite aerogel in a one-step conversion process from a precursor mixture.

Dicarboxylic Acid Emissions from Aftertreatment Equipped Diesel Engines.

Dicarboxylic acids play a key role in atmospheric particle nucleation. Though long assumed to originate from primary sources, little experimental evidence exists directly linking combustion to their emissions. In this work, we sought definitive proof that dicarboxylic acids are produced in diesel engines and that they can slip through a modern aftertreatment system (ATS) at low exhaust temperatures.