A Semi-Quantitative Approach to Nontarget Compositional Analysis of Complex Samples.

Nontarget analysis (NTA) by liquid chromatography coupled to high-resolution mass spectrometry improves the capacity to comprehend the molecular composition of complex mixtures compared to targeted analysis techniques. However, the detection of unknown compounds means that quantification in NTA is challenging. This study proposes a new semi-quantitative methodology for use in the NTA of organic aerosol.

Adsorption of per- and polyfluoroalkyl substances on biochar derived from municipal sewage sludge.

Granular activated carbon (GAC) and ion exchange resin (IXR) are widely used as adsorbents to remove PFAS from drinking water sources and effluent waste streams. However, the high cost associated with GAC and IXR generation has motivated the development of less expensive adsorbents for treatment of PFAS-impacted water. Thus, the objective of this research was to create an economically viable and sustainable PFAS adsorbent from sewage sludge.

Solvent-Dependent Emissions Properties of a Model Aurone Enable Use in Biological Applications.

Fluorophores are powerful visualization tools and the development of novel small organic fluorophores are in great demand. Small organic fluorophores have been derived from the aurone skeleton, 2-benzylidenebenzofuran-3(2H)-one. In this study, we have utilized a model aurone derivative with a methoxy group at the 3' position and a hydroxyl group at the 4' position, termed vanillin aurone, to develop a foundational understanding of structural factors impacting aurone fluorescence properties.

Semitransparent Organic Photovoltaics Utilizing Intrinsic Charge Generation in Non-Fullerene Acceptors.

In organic semiconductors, a donor/acceptor heterojunction is typically required for efficient dissociation of excitons. Using transient absorption spectroscopy to study the dynamics of excited states in non-fullerene acceptors (NFAs), it is shown that NFAs can generate charges without a donor/acceptor interface. This is due to the fact that dielectric solvation provides a driving force sufficient to dissociate the excited state and form the charge-transfer (CT) state.

Extreme Concentrations of Nitric Oxide Control Daytime Oxidation and Quench Nocturnal Oxidation Chemistry in Delhi during Highly Polluted Episodes.

Delhi, India, suffers from periods of very poor air quality, but little is known about the chemical production of secondary pollutants in this highly polluted environment. During the postmonsoon period in 2018, extremely high nighttime concentrations of NO (NO and NO) and volatile organic compounds (VOCs) were observed, with median NO mixing ratios of ∼200 ppbV (maximum of ∼700 ppbV). A detailed chemical box model constrained to a comprehensive suite of speciated VOC and NO measurements revealed very low nighttime concentrations of oxidants, NO, O, and OH, driven by high nighttime NO concentrations.

Influence of convective and stratiform precipitation types on per- and polyfluoroalkyl substance concentrations in rain.

Atmospheric transport and wet deposition have contributed to the worldwide distribution of per- and polyfluoroalkyl substances (PFAS) in terrestrial and aquatic ecosystems, even in remote areas far from known industrial sources. However, little is known regarding the impact of cloud and precipitation formation dynamics on PFAS transport and wet deposition, nor the range of variability in PFAS concentrations within a closely distributed monitoring network. Precipitation samples were collected from a network of 25 stations in a focused geographic region (the Commonwealth of Massachusetts, USA) from stratiform and convective storm systems to evaluate if the different cloud and precipitation formation mechanisms in these two fundamental types of storm systems influenced PFAS concentrations in precipitation, and to assess the range of variability in PFAS concentrations in precipitation at a regional scale.

Low-temperature persulfate activation by powdered activated carbon for simultaneous destruction of perfluorinated carboxylic acids and 1,4-dioxane.

Carbonaceous materials have emerged as a method of persulfate activation for remediation. In this study, persulfate activation using powdered activated carbon (PAC) was demonstrated at temperatures relevant to groundwater (5-25 °C). At room temperature, increasing doses of PAC (1-20 g L) led to increased persulfate activation (3.

Aurone-derived 1,2,3-triazoles as potential fluorescence molecules .

Aurones are a class of well-studied natural compounds primarily responsible for the yellow pigment in flowering plants and have been shown to have fluorescent properties as well as beneficial biological effects. Traditionally, aurones can be easily synthesized through a Knoevenagel condensation of benzofuranones with arylaldehydes. Recently, Kafle unexpectedly synthesized a new aurone derivative containing a 1,2,3-triazole within its backbone.

The SWI/SNF ATPase BRG1 facilitates multiple pro-tumorigenic gene expression programs in SMARCB1-deficient cancer cells.

Malignant rhabdoid tumor (MRT) is driven by the loss of the SNF5 subunit of the SWI/SNF chromatin remodeling complex and then thought to be maintained by residual SWI/SNF (rSWI/SNF) complexes that remain present in the absence of SNF5. rSWI/SNF subunits colocalize extensively on chromatin with the transcription factor MYC, an oncogene identified as a novel driver of MRT. Currently, the role of rSWI/SNF in modulating MYC activity has neither been delineated nor has a direct link between rSWI/SNF and other oncogenes been uncovered.

Single-payer Health Care: Financial Implications for a Physician.

When considering proposed reforms of the U.S. health care system, some physicians dismiss the single-payer model (Medicare for All or state-based universal health care proposals) out of concern that their reimbursement and thus their income would be reduced.

An Automated Methodology for Non-targeted Compositional Analysis of Small Molecules in High Complexity Environmental Matrices Using Coupled Ultra Performance Liquid Chromatography Orbitrap Mass Spectrometry.

The life-critical matrices of air and water are among the most complex chemical mixtures that are ever encountered. Ultrahigh-resolution mass spectrometers, such as the Orbitrap, provide unprecedented analytical capabilities to probe the molecular composition of such matrices, but the extraction of non-targeted chemical information is impractical to perform via manual data processing. Automated non-targeted tools rapidly extract the chemical information of all detected compounds within a sample dataset.

Influence of aqueous film forming foams on the solubility and mobilization of non-aqueous phase liquid contaminants in quartz sands.

At sites where aqueous film forming foams (AFFFs) are used for fire suppression or training activities, interactions between dissolved foam constituents and organic liquids could alter contaminant migration in the subsurface. In this study, batch reactor and column experiments were conducted to investigate the potential for AFFF solutions to enhance the solubility and mobility of three representative non-aqueous phase liquid (NAPLs), JP-4 jet fuel, trichloroethene (TCE), and tetrachloroethene (PCE). For AFFF concentrations up to 5% wt.

Using highly time-resolved online mass spectrometry to examine biogenic and anthropogenic contributions to organic aerosol in Beijing.

Organic aerosols, a major constituent of fine particulate mass in megacities, can be directly emitted or formed from secondary processing of biogenic and anthropogenic volatile organic compound emissions. The complexity of volatile organic compound emission sources, speciation and oxidation pathways leads to uncertainties in the key sources and chemistry leading to formation of organic aerosol in urban areas. Historically, online measurements of organic aerosol composition have been unable to resolve specific markers of volatile organic compound oxidation, while offline analysis of markers focus on a small proportion of organic aerosol and lack the time resolution to carry out detailed statistical analysis required to study the dynamic changes in aerosol sources and chemistry.

Key Role of NO Radicals in the Production of Isoprene Nitrates and Nitrooxyorganosulfates in Beijing.

The formation of isoprene nitrates (IsN) can lead to significant secondary organic aerosol (SOA) production and they can act as reservoirs of atmospheric nitrogen oxides. In this work, we estimate the rate of production of IsN from the reactions of isoprene with OH and NO radicals during the summertime in Beijing. While OH dominates the loss of isoprene during the day, NO plays an increasingly important role in the production of IsN from the early afternoon onwards.

Association of adverse childhood experiences (ACEs) and substance use disorders (SUDs) in a multi-site safety net healthcare setting.

Background: Adverse childhood experiences (ACEs) and substance use disorders (SUDs) are highly prevalent public health challenges that have been shown to be strongly correlated. Although previous research has suggested a dose-response relationship between ACEs and SUDs, less is known about this phenomenon and the prevalence of ACEs in lower income, racially/ethnically diverse populations. This study sought to examine these relationships in a population treated at a multi-site safety net provider.

(North American Ginseng) Polysaccharides as Immunomodulators: Current Research Status and Future Directions.

(North American ginseng, NAG) is a popular medicinal plant used widely in traditional medicine. NAG products are currently available in various forms such as roots, extracts, nutraceuticals, dietary supplements, energy drinks, etc. NAG polysaccharides are recognized as one of the major bioactive ingredients.

An acidic polysaccharide (AGC3) isolated from North American ginseng () suspension culture as a potential immunomodulatory nutraceutical.

Polysaccharides isolated from roots are widely used as nutraceuticals due to their immunomodulatory properties. Despite their popularity, several challenges exist in isolating ginseng root polysaccharides such as batch-to-batch structural inconsistencies and bacterial endotoxin contamination. A plant tissue culture-based platform offers a potential solution to isolate natural polysaccharide fractions with consistent chemical characteristics and reduced endotoxin content.

The rise of adverse childhood experiences during the COVID-19 pandemic.

Adverse childhood experiences, which is defined by different forms of abuse, neglect, and household dysfunction occurring before the age of 18 years, is a major public health problem in the United States that has the potential to worsen in the current COVID-19 pandemic. Moreover, the challenge is even greater for children and youth from low-income communities and communities of color. Thus, there is a greater need for investments in youth-serving systems within and beyond health care and public health to effectively address adverse childhood experiences and prevent its short- and long-term negative health and social sequelae well beyond the current public health crisis.

Panax quinquefolius (North American ginseng) cell suspension culture as a source of bioactive polysaccharides: Immunostimulatory activity and characterization of a neutral polysaccharide AGC1.

In this study, we propose the use of a plant tissue culture-based system for the production of polysaccharides with consistent chemical characteristics and reduced endotoxin content. Polysaccharides were isolated from suspension cultures of Panax quinquefolius (American ginseng), a widely used medicinal herb. A neutral fraction, AGC1, purified by anion exchange and size exclusion chromatography, displayed immunostimulatory activity in vitro and ex vivo.

Isolation, structure elucidation, and immunostimulatory activity of polysaccharide fractions from Boswellia carterii frankincense resin.

Frankincense has a long history in religious, cultural, and medicinal use. In this study polysaccharides were extracted from frankincense from Boswellia carterii. The polysaccharides were purified by anion exchange chromatography on a DEAE-Sepharose Fast Flow 16/10 FPLC column.

The Role of the Side Chain on the Performance of N-type Conjugated Polymers in Aqueous Electrolytes.

We report a design strategy that allows the preparation of solution processable n-type materials from low boiling point solvents for organic electrochemical transistors (OECTs). The polymer backbone is based on NDI-T2 copolymers where a branched alkyl side chain is gradually exchanged for a linear ethylene glycol-based side chain. A series of random copolymers was prepared with glycol side chain percentages of 0, 10, 25, 50, 75, 90, and 100 with respect to the alkyl side chains.

Alternative Thieno[3,2-b][1]benzothiophene Isoindigo Polymers for Solar Cell Applications.

This work reports the synthesis, characterization, photophysical, and photovoltaic properties of five new thieno[3,2-b][1]benzothiophene isoindigo (TBTI)-containing low bandgap donor-acceptor conjugated polymers with a series of comonomers and different side chains. When TBTI is combined with different electron-rich moieties, even small structural variations can have significant impact on thin film morphology of the polymer:phenyl C70 butyric acid methyl ester (PCBM) blends. More importantly, high-resolution electron energy loss spectroscopy is used to investigate the phase-separated bulk heterojunction domains, which can be accurately and precisely resolved, enabling an enhanced correlation between polymer chemical structure, photovoltaic device performance, and morphology.

Evidence for ion migration in hybrid perovskite solar cells with minimal hysteresis.

Ion migration has been proposed as a possible cause of photovoltaic current-voltage hysteresis in hybrid perovskite solar cells. A major objection to this hypothesis is that hysteresis can be reduced by changing the interfacial contact materials; however, this is unlikely to significantly influence the behaviour of mobile ionic charge within the perovskite phase. Here, we show that the primary effects of ion migration can be observed regardless of whether the contacts were changed to give devices with or without significant hysteresis.

Experimental and theoretical optical properties of methylammonium lead halide perovskites.

The optical constants of methylammonium lead halide single crystals CH3NH3PbX3 (X = I, Br, Cl) are interpreted with high level ab initio calculations using the relativistic quasiparticle self-consistent GW approximation (QSGW). Good agreement between the optical constants derived from QSGW and those obtained from spectroscopic ellipsometry enables the assignment of the spectral features to their respective inter-band transitions. We show that the transition from the highest valence band (VB) to the lowest conduction band (CB) is responsible for almost all the optical response of MAPbI3 between 1.