Thin layer cell behavior of CNT yarn and cavity carbon nanopipette electrodes: Effect on catecholamine detection.

Carbon nanotube yarn microelectrodes (CNTYMEs) are an alternative to carbon-fiber microelectrodes (CFMEs) with interesting electrochemical properties because analyte is momentarily trapped in cavities between the CNTs. Here, we compare fast-scan cyclic voltammetry (FSCV) detection of catecholamines, including dopamine, norepinephrine, and epinephrine, at CNTYMEs, CFMEs, as well as cavity carbon nanopipette electrodes (CNPEs). At CFMEs, current decreases dramatically at high FSCV repetition frequencies.

The Cold-Unfolded State Is Expanded but Contains Long- and Medium-Range Contacts and Is Poorly Described by Homopolymer Models.

Cold unfolding of proteins is predicted by the Gibbs-Helmholtz equation and is thought to be driven by a strongly temperature-dependent interaction of protein nonpolar groups with water. Studies of the cold-unfolded state provide insight into protein energetics, partially structured states, and folding cooperativity and are of practical interest in biotechnology. However, structural characterization of the cold-unfolded state is much less extensive than studies of thermally or chemically denatured unfolded states, in large part because the midpoint of the cold unfolding transition is usually below freezing.

PTSD and Depressive Symptoms as Potential Mediators of the Association between World Trade Center Exposure and Subjective Cognitive Concerns in Rescue/Recovery Workers.

We observed that World Trade Center (WTC) exposure, post-traumatic stress disorder (PTSD) symptoms and depressive symptoms were associated with subjective cognitive concerns in Fire Department of the City of New York (FDNY) rescue/recovery workers. This follow-up study examined whether PTSD symptoms and/or depressive symptoms mediate the observed association between WTC exposure and subjective cognitive concerns. We included WTC-exposed FDNY workers who completed the Cognitive Function Instrument (CFI), measuring self-perceived cognitive decline ( = 9516).

Evolutionary algorithms converge towards evolved biological photonic structures.

Nature features a plethora of extraordinary photonic architectures that have been optimized through natural evolution in order to more efficiently reflect, absorb or scatter light. While numerical optimization is increasingly and successfully used in photonics, it has yet to replicate any of these complex naturally occurring structures. Using evolutionary algorithms inspired by natural evolution and performing particular optimizations (maximize reflection for a given wavelength, for a broad range of wavelength or maximize the scattering of light), we have retrieved the most stereotypical natural photonic structures.

Cytochrome c oxidase oxygen reduction reaction induced by cytochrome c on nickel-coordination surfaces based on graphene oxide in suspension.

Background: The electrochemical and spectroscopic investigation of bacterial electron-transfer proteins stabilized on solid state electrodes has provided an effective approach for functional respiratory enzyme studies.

Methods: We assess the biocompatibility of carboxylated graphene oxide (CGO) functionalized with Nickel nitrilotriacetic groups (CGO-NiNTA) ccordinating His-tagged cytochrome c oxidase (CcO) from Rhodobacter sphaeroides.

Results: Kinetic studies employing UV-visible absorption spectroscopy confirmed that the immobilized CcO oxidized horse-heart cytochrome c (Cyt c) albeit at a slower rate than isolated CcO.

Keep a lid on it: A troika in kinase allostery.

The malaria parasite encodes a cGMP-dependent protein kinase G (PKG) that is critical for its life cycle. Specific cGMP analogs are able to act as partial agonists of PKG. Using the exquisite diagnostic power of NMR chemical shifts, Byun demonstrate that the extent of agonism by these cGMP derivatives relates to the degree of stabilization of a unique inactive conformation that shares structural features with both the ligand-free, inactive and the cGMP-bound, active states.

Willingness to Distribute HIV Self-Testing Kits to Recent Sex Partners Among HIV-Negative Gay and Bisexual Men and an Examination of Free-Response Data from Young Men Participating in the Nationwide Cohort.

Sexual minority men (SMM)-and young SMM in particular-are disproportionately affected by HIV. Secondary distribution of HIV self-testing (HIVST) kits-wherein patients deliver kits to partners-is a novel strategy to increase HIV testing access. Using quantitative data, we assessed willingness to distribute HIVST kits to recent sex partners among a U.

Designer Topological Insulator with Enhanced Gap and Suppressed Bulk Conduction in BiSe/SbTe Ultrashort-Period Superlattices.

A novel approach to suppress bulk conductance in three-dimensional (3D) topological insulators (TIs) using short-period superlattices (SLs) of two TIs is presented. Evidence for superlattice gap enhancement (SGE) was obtained from the reduction of bulk background doping from 1.2 × 10 cm to 8.

Drug Use Among Adolescents and Young Adults with Unsuppressed HIV Who Use Alcohol: Identifying Patterns of Comorbid Drug Use and Associations with Mental Health.

Youth living with HIV (YLWH; aged 16-24) are at elevated risk of alcohol and drug use. Studies in older populations have identified patterns or profiles of multiple substance use differentially associated with mental health and anti-retroviral therapy (ART) adherence. No studies of YLWH have yet examined such patterns.

Resistive-Pulse Sensing Inside Single Living Cells.

Resistive-pulse sensing is a technique widely used to detect single nanoscopic entities such as nanoparticles and large molecules that can block the ion current flow through a nanopore or a nanopipette. Although the species of interest, e.g.

A bifunctional ATPase drives tad pilus extension and retraction.

A widespread class of prokaryotic motors powered by secretion motor adenosine triphosphatases (ATPases) drives the dynamic extension and retraction of extracellular fibers, such as type IV pili (T4P). Among these, the tight adherence (tad) pili are critical for surface sensing and biofilm formation. As for most other motors belonging to this class, how tad pili retract despite lacking a dedicated retraction motor ATPase has remained a mystery.

Spirituality and Multiple Dimensions of Religion Are Associated with Mental Health in Gay and Bisexual Men: Results From the Cohort.

The purpose of this study was to determine the association between religion, spirituality, and mental health among gay and bisexual men (GBM). A U.S.

PACAP27 mitigates an age-dependent hippocampal vulnerability to PGJ2-induced spatial learning deficits and neuroinflammation in mice.

Background: Inflammation in the brain is mediated by the cyclooxygenase pathway, which leads to the production of prostaglandins. Prostaglandin (PG) D2, the most abundant PG in the brain, increases under pathological conditions and is spontaneously metabolized to PGJ2. PGJ2 is highly neurotoxic, with the potential to transition neuroinflammation into a chronic state and contribute to neurodegeneration as seen in many neurological diseases.

Enacted individual-level stigma, anticipated relationship stigma, and negative affect among unpartnered sexual minority individuals.

Purpose: To examine associations of enacted individual-level stigma and anticipated relationship stigma with negative affect among single sexual minority individuals. We hypothesized that enacted individual-level stigma and anticipated relationship stigma would be positively associated with negative affect. We also explored possible mediation models of how these variables might relate.

TEM-Assisted Fabrication of Sub-10 nm Scanning Electrochemical Microscopy Tips.

High-resolution scanning electrochemical microscopy (SECM) is a powerful technique for mapping surface topography and reactivity on the nanoscale and investigating heterogeneous processes at the level of single nanoparticles. The ability to fabricate ultrasmall nanoelectrode tips is critical for the progress in nano-SECM. Despite long-term efforts to improve previously developed procedures, the preparation and characterization of disk-type polished tips with the radius <∼25 nm remains challenging and unpredictable.

Cell-line-based assay for the toxicity/benefit analysis of lipopolysaccharides in plants.

There are many immune-boosting medicinal plants that can potently activate innate immune cells. Recent studies indicate that the active factors of some immune-boosting plants are lipopolysaccharides (LPSs) of plant-associated bacteria. However, little is currently known about the potential risk and benefit of LPSs in medicinal plants.

World Trade Center exposure, post-traumatic stress disorder, and subjective cognitive concerns in a cohort of rescue/recovery workers.

Objective: To determine whether World Trade Center (WTC)-exposure intensity and post-traumatic stress disorder (PTSD) are associated with subjective cognitive change in rescue/recovery workers.

Method: The population included 7875 rescue/recovery workers who completed a subjective cognition measure, the Cognitive Function Instrument (CFI), between 3/1/2018 and 2/28/2019 during routine monitoring, indicating whether they had experienced cognitive and functional difficulties in the past year. Higher scores indicated greater self-perceived cognitive change.

The role of calcium in the interaction between calmodulin and a minimal functional construct of eukaryotic elongation factor 2 kinase.

Eukaryotic elongation factor 2 kinase (eEF-2K) regulates protein synthesis by phosphorylating eukaryotic elongation factor 2 (eEF-2), thereby reducing its affinity for the ribosome and suppressing global translational elongation rates. eEF-2K is regulated by calmodulin (CaM) through a mechanism that is distinct from that of other CaM-regulated kinases. We had previously identified a minimal construct of eEF-2K (TR) that is activated similarly to the wild-type enzyme by CaM in vitro and retains its ability to phosphorylate eEF-2 efficiently in cells.

Photo-Scanning Electrochemical Microscopy on the Nanoscale with Through-Tip Illumination.

Scanning electrochemical microscopy (SECM) has previously been employed in probing photoelectrochemical processes at semiconductor surfaces. However, the spatial resolution of these studies has not yet matched the nanoscale SECM resolution attained without substrate illumination. Herein, we introduce nanoscale photo-SECM with a glass-sealed, polished tip simultaneously serving as a nanoelectrode and a light guide to produce a microscopic light spot on the substrate surface.

Ultrasensitive Detection of Dopamine with Carbon Nanopipets.

Carbon fiber micro- and nanoelectrodes have been extensively used to measure dopamine and other neurotransmitters in biological systems. Although the radii of some reported probes were ≪1 μm, the lengths of the exposed carbon were typically on the micrometer scale, thus limiting the spatial resolution of electroanalytical measurements. Recent attempts to determine neurotransmitters in single cells and vesicles have provided additional impetus for decreasing the probe dimensions.

Comparing the Role of Aberrant Salience and Dissociation in the Relation between Cumulative Traumatic Life Events and Psychotic-Like Experiences in a Multi-Ethnic Sample.

Exposure to traumatic life events (TLE) is a risk factor for psychosis. Yet, a dearth of studies examines factors linking TLE to psychosis, while considering differences in TLE frequency. This study investigated dissociation and aberrant salience as mediators and moderators of the relation between three TLE groups (none, 1-3 TLE and 4+ TLE) and psychotic-like experiences (PLE) in a multi-ethnic sample of 816 emerging adults.

Relationship functioning and substance use in same-sex male couples.

Background: Research suggests that substance use among partnered sexual minority men will be inversely associated with the quality of dyadic functioning. We tested whether dimensions of relationship functioning implied within Couples Interdependence Theory (e.g.