A facile method for separating fine water droplets dispersed in oil through a pre-wetted mesh membrane.

To achieve the successful separation of emulsions containing fine dispersed droplets and low volume fractions, a membrane with pore sizes comparable to or smaller than the droplet size is typically required. Although this approach is effective, its utilization is limited to the separation of emulsions with relatively large droplets. To overcome this limitation, a secondary membrane can be formed on the primary membrane to reduce pore size, but this can also be time-consuming and costly. Therefore, a facile and effective method is still required to be developed for separating emulsions with fine droplets. We introduce a pre-wetted mesh membrane with a pore size significantly larger than droplets, easily fabricated by wetting a hydrophilic stainless-steel mesh with water. Applying this membrane to emulsion separation via gravity-driven flow confirms a high efficiency greater than 98%, even with droplets approximately 10 times smaller than the pore size.

Implementation of Sexual Health Curriculum Series: Educational Initiative to Increase STI Screening and Treatment in Dallas, Texas.

OBJECTIVE: A new monthly virtual education curriculum on sexual healthcare was launched in 2021. This is an analysis of the pilot education series designed to increase primary care providers' knowledge of sexual health best practices including taking thorough sexual histories, STI screening and treatment, and PrEP prescribing. METHODS: A Sexual Health Curriculum Series was developed as part of a quality improvement initiative at a large urban safety-net hospital in Dallas County, Texas. Didactic sessions were administered to primary care providers and staff via a virtual meeting platform once a month from May 2021 to April 2022. RESULTS: A total of 52 participants completed the pre-series survey, and 21 participants filled out the final post-series survey. 70% of respondents who completed the post-series survey reported that they learned new information that was incorporated into their practice. The average percentage correct on individual pre-session surveys was 60% compared to 63% on individual post-session surveys (p = 0.03). CONCLUSION: Sexual health education is an important tool to help primary care providers adhere to sexual health best practices. There is a need for ongoing implementation of innovative strategies to improve knowledge and adherence to sexual health best practices. A sexual health curriculum may be effective in helping primary providers recognize patients at increased risk and apply evidence-based guidelines to their practices.

Quantitative Fluorescence Analysis Reveals Dendrite-Specific Thalamocortical Plasticity in L5 Pyramidal Neurons during Learning.

High-throughput anatomic data can stimulate and constrain new hypotheses about how neural circuits change in response to experience. Here, we use fluorescence-based reagents for presynaptic and postsynaptic labeling to monitor changes in thalamocortical synapses onto different compartments of layer 5 (L5) pyramidal (Pyr) neurons in somatosensory (barrel) cortex from mixed-sex mice during whisker-dependent learning (Audette et al., 2019). Using axonal fills and molecular-genetic tags for synapse identification in fixed tissue from Rbp4-Cre transgenic mice, we found that thalamocortical synapses from the higher-order posterior medial thalamic nucleus showed rapid morphologic changes in both presynaptic and postsynaptic structures at the earliest stages of sensory association training. Detected increases in thalamocortical synaptic size were compartment specific, occurring selectively in the proximal dendrites onto L5 Pyr and not at inputs onto their apical tufts in L1. Both axonal and dendritic changes were transient, normalizing back to baseline as animals became expert in the task. Anatomical measurements were corroborated by electrophysiological recordings at different stages of training. Thus, fluorescence-based analysis of input- and target-specific synapses can reveal compartment-specific changes in synapse properties during learning.SIGNIFICANCE STATEMENT Synaptic changes underlie the cellular basis of learning, experience, and neurologic diseases. Neuroanatomical methods to assess synaptic plasticity can provide critical spatial information necessary for building models of neuronal computations during learning and experience but are technically and fiscally intensive. Here, we describe a confocal fluorescence microscopy-based analytical method to assess input, cell type, and dendritic location-specific synaptic plasticity in a sensory learning assay. Our method not only confirms prior electrophysiological measurements but allows us to predict functional strength of synapses in a pathway-specific manner. Our findings also indicate that changes in primary sensory cortices are transient, occurring during early learning. Fluorescence-based synapse identification can be an efficient and easily adopted approach to study synaptic changes in a variety of experimental paradigms.

IEG expression defines SST neuron ensembles critical for motor learning.

Neocortical interneurons have been hypothesized to be important for circuit reorganization during learning. In this issue of Neuron, Yang et al. (2022) identify a subset of Npas4-expressing somatostatin interneurons that help regulate excitatory synaptic plasticity during motor learning.

Effect of the COVID-19 Pandemic on Chlamydial Infection Treatment in Women Discharged From an Urban Safety-Net Emergency Unit.

BACKGROUND: Chlamydia is the most frequently reported sexually transmitted infection. COVID-19 exacerbated the challenges in treating and preventing new Chlamydia trachomatis (CT) infections. This study examined the impact of COVID-19 on treating CT-positive patients discharged from a safety-net women's emergency unit. METHODS: This was a preretrospective and postretrospective cohort study. Chlamydia trachomatis -positive female patients seen in the women's emergency unit were evaluated. Patients discharged in 2019, the "pre-COVID-19" group, and those discharged in 2020, the "COVID-19" group, were compared. The primary outcome was CT treatment within 30 days, and secondary outcomes included prescription dispensation, repeat tests taken, and expedited partner treatment. A subgroup of patients discharged before treatment who entered a nurse-led follow-up program was also evaluated. RESULTS: Of the 1357 cases included, there were no differences in successful 30-day treatment (709 of 789 [89.9%] vs. 568 of 511 [89.9%], P = 0.969) or repeat positive CT test (74 of 333 [22.2%] vs. 46 of 211 [21.8%]), P = 0.36) between pre-COVID-19 and COVID-19. However, the patients who picked up their prescription (196 of 249 [78.7%] vs. 180 of 206 [87.4%], P = 0.021) and those who were prescribed expedited partner therapy (156 of 674 [23.1%] vs. 292 of 460 [63.5%], P < 0.001) increased. Findings in the subgroup of patients who entered the follow-up program were consistent with those in the full cohort. CONCLUSIONS: The COVID-19 pandemic did not change treatment patterns of CT-positive patients in this safety-net women's emergency unit. However, patients were more likely to pick up their medications during COVID-19. Despite the perseverance of these programs through the pandemic, most patients are discharged before positive results, and a fair amount remain untreated.

FosGFP expression does not capture a sensory learning-related engram in superficial layers of mouse barrel cortex.

Immediate-early gene (IEG) expression has been used to identify small neural ensembles linked to a particular experience, based on the principle that a selective subset of activated neurons will encode specific memories or behavioral responses. The majority of these studies have focused on "engrams" in higher-order brain areas where more abstract or convergent sensory information is represented, such as the hippocampus, prefrontal cortex, or amygdala. In primary sensory cortex, IEG expression can label neurons that are responsive to specific sensory stimuli, but experience-dependent shaping of neural ensembles marked by IEG expression has not been demonstrated. Here, we use a fosGFP transgenic mouse to longitudinally monitor in vivo expression of the activity-dependent gene c-fos in superficial layers (L2/3) of primary somatosensory cortex (S1) during a whisker-dependent learning task. We find that sensory association training does not detectably alter fosGFP expression in L2/3 neurons. Although training broadly enhances thalamocortical synaptic strength in pyramidal neurons, we find that synapses onto fosGFP+ neurons are not selectively increased by training; rather, synaptic strengthening is concentrated in fosGFP- neurons. Taken together, these data indicate that expression of the IEG reporter fosGFP does not facilitate identification of a learning-specific engram in L2/3 in barrel cortex during whisker-dependent sensory association learning.

Covalent organic framework-supported platinum nanoparticles as efficient electrocatalysts for water reduction.

The hydrogen evolution reaction (HER) is one of the most effective and sustainable ways to produce hydrogen gas as an alternative clean fuel. The rate of this electrocatalytic reaction is highly dependent on the properties (dispersity and stability) of electrocatalysts. Herein, we developed well-dispersed and highly stable platinum nanoparticles (PtNPs) supported on a covalent organic framework (COF-bpyTPP), which exhibit excellent catalytic activities toward HER as well as the hydride reduction reaction. The nanoparticles have an average size of 2.95 nm and show superior catalytic performance compared to the commercially available Pt/C under the same alkaline conditions, producing 13 times more hydrogen with a far more positive onset potential (-0.13 V vs.-0.63 V) and ca. 100% faradaic efficiency. The reaction rate of the hydride reduction of 4-nitrophenol was also 10 times faster in the case of PtNPs@COF compared to the commercial Pt/C under the same loading and conditions. More importantly, the PtNPs@COF are highly stable under the aqueous reactions conditions and can be reused without showing noticeable aggregation and activity degradation.

Fluorescence-Based Quantitative Synapse Analysis for Cell Type-Specific Connectomics.

Anatomical methods for determining cell type-specific connectivity are essential to inspire and constrain our understanding of neural circuit function. We developed genetically-encoded reagents for fluorescence-synapse labeling and connectivity analysis in brain tissue, using a fluorogen-activating protein (FAP)-coupled or YFP-coupled, postsynaptically-localized neuroligin-1 (NL-1) targeting sequence (FAP/YFPpost). FAPpost expression did not alter mEPSC or mIPSC properties. Sparse AAV-mediated expression of FAP/YFPpost with the cell-filling, red fluorophore dTomato (dTom) enabled high-throughput, compartment-specific detection of putative synapses across diverse neuron types in mouse somatosensory cortex. We took advantage of the bright, far-red emission of FAPpost puncta for multichannel fluorescence alignment of dendrites, FAPpost puncta, and presynaptic neurites in transgenic mice with saturated labeling of parvalbumin (PV), somatostatin (SST), or vasoactive intestinal peptide (VIP)-expressing neurons using Cre-reporter driven expression of YFP. Subtype-specific inhibitory connectivity onto layer 2/3 (L2/3) neocortical pyramidal (Pyr) neurons was assessed using automated puncta detection and neurite apposition. Quantitative and compartment-specific comparisons show that PV inputs are the predominant source of inhibition at both the soma and the dendrites and were particularly concentrated at the primary apical dendrite. SST inputs were interleaved with PV inputs at all secondary-order and higher-order dendritic branches. These fluorescence-based synapse labeling reagents can facilitate large-scale and cell-type specific quantitation of changes in synaptic connectivity across development, learning, and disease states.

Separation of Arylenevinylene Macrocycles with a Surface-Confined Two-Dimensional Covalent Organic Framework.

A two-dimensional surface covalent organic framework, prepared by a surface-confined synthesis using 4,4'-azodianiline and benzene-1,3,5-tricarbaldehyde as the precursors, was used as a host network to effectively immobilize arylenevinylene macrocycles (AVMs). Thus AVMs could be separated from their linear polymer analogues, which are the common side-products in the cyclooligomerization process. Scanning tunneling microscopy investigations revealed efficient removal of linear polymers by a simple surface binding and solvent washing process.

Surface-Confined Dynamic Covalent System Driven by Olefin Metathesis.

Understanding how the constitutional dynamics of a dynamic combinatorial library (DCL) adapts to surfaces (compared to bulk solution) is of fundamental importance to the design of adaptive materials. Submolecular resolved scanning tunneling microscopy (STM) can provide detailed insights into olefin metathesis at the interface. Analysis of the distribution of products has revealed the important role of environmental pressure, reaction temperature, and substituent effects in surface-confined olefin metathesis. We also report an unprecedented preferred deposition and assembly of linear polymers, and some specific oligomers, on the surface that are hard to obtain otherwise.

Multicatalytic, Light-Driven Upgrading of Butanol to 2-Ethylhexenal and Hydrogen under Mild Aqueous Conditions.

Microbes produce low-molecular-weight alcohols from sugar, but these metabolites are difficult to separate from water and possess relatively low heating values. A combination of photo-, organo-, and enzyme catalysis is shown here to convert C4 butanol (BuOH) to C8 2-ethylhexenal (2-EH) using only solar energy to drive the process. First, alcohol dehydrogenase (ADH) catalyzed the oxidation of BuOH to butyraldehyde (BA), using NAD+ as a cofactor. To prevent back reaction, NAD+ was regenerated using a platinum-seeded cadmium sulfide (Pt@CdS) photocatalyst. An amine-based organocatalyst then upgraded BA to 2-EH under mild aqueous conditions rather than harsh basic conditions in order to preserve enzyme and photocatalyst stability. The process also simultaneously increased total BuOH conversion. Thus, three disparate types of catalysts synergistically generated C8 products from C4 alcohols under green chemistry conditions of neutral pH, low temperature, and pressure.

Semiconductor-Based, Solar-Driven Photochemical Cells for Fuel Generation from Carbon Dioxide in Aqueous Solutions.

There has been active interest to identify new methods to reduce CO2 into usable fuel sources. In this work, we demonstrate two types of photo-electrochemical cells (PECs) that photoreduce CO2 directly to formate in aqueous solutions both in the presence and absence of external bias or additional electron sources. The photocathodes were either a CuFeO2 /CuO electrode or a bilayer of CdTe on NiO, whereas the photoanode was a bilayer of NiOx on CdS. The PECs were characterized by using both electrochemistry and spectroscopy, and the products formed from CO2 reduction were characterized and quantified by using 1 H NMR spectroscopy and ESI-MS. In addition, an organohydride catalyst was tested in conjunction with the PECs, which not only showed a significant gain of 85 times in CO2 reduction (27 µm formate without the catalyst, 2.3 mm formate with it) compared to the NiO/CdTe photocathode system but could also generate methanol under an external bias (10 µm).

Solid-state photogalvanic dye-sensitized solar cells.

Photogalvanic cells are photoelectrochemical systems wherein the semiconductor electrode is not a participant in primary photoinduced charge formation. The discovery of photoelectrochemical systems that successfully exploit secondary (thermal) electron injection at dye-semiconductor interfaces may enable studies of electron transfer at minimal driving force for electron injection into the semiconductor. In this study, we have examined thermal electron transfer from molecular sensitizers to nanostructured semiconductor electrodes composed of titanium dioxide nanorods by means of transient spectroscopy and the assembly and testing of photoelectrochemical cells. Electron-accepting molecular dyes have been studied alongside an arylamine electron donor. Thermal injection is estimated for a naphthacenequinone radical anion as a multiexponential decay process with initial decay lifetimes of 6 and 27 ps. The ambient electric field present during charge separation at a surface-adsorbed dye monolayer causes Stark shifts of the radical ion pair absorbance peaks that confounded kinetic estimation of thermal injection for a fullerene sensitizer. Electron-accepting dyes that operate by thermal injection into titanium dioxide function better in solid-state photoelectrochemical cells than in liquid-junction cells due to the kinetic advantage of solid-state cells with respect to photoinduced acceptor-quenching to form the necessary radical anion sensitizers.

Optoelectronic tuning of organoborylazadipyrromethenes via effective electronegativity at the metalloid center.

Organoborylazadipyrromethenes were synthesized from free base and fluoroborylazadipyrromethenes and characterized with regard to their structural and electronic properties. B-N bond lengths, along with photophysical and redox behavior, appear dependent on the effective electronegativity at the boron atom as tuned by its substituents, with stronger electronegativity correlating to a shorter B-N bond length, red-shifted absorbance, enhanced fluorescence lifetime and yield, and positively shifted redox potentials.