Search

Employing neutral impact collision ion scattering spectroscopy (NICISS), we have directly measured the concentration depth profiles (CDPs) of various monovalent ions at the vapor-formamide interface. NICISS provides CDPs of individual ions by measuring the energy loss of neutral helium atoms backscattered from the solution interface. CDPs at the vapor-formamide interface of Cl - , Br - , I - , Na + , K + , and Cs + are measured and compared to elucidate the interfacial specific ion trends. We report a reverse Hofmeister series in the presence of inorganic ions (anion and cation) at the vapor-formamide interface relative to the water-vapor interface, and the CDPs are found to be independent of the counterion for most ions studied. Thus, ions at the surface of formamide follow a "Hofmeister paradigm" where the counterion does not impact the ion series. These specific ion trends are complemented with surface tension and X-ray absorption near-edge structure (XANES) measurements on formamide electrolyte solutions.

This study describes the capabilities and limitations of carrying out total scattering experiments on the Powder Diffraction (PD) beamline at the Australian Synchrotron, ANSTO. A maximum instrument momentum transfer of 19 Å -1 can be achieved if the data are collected at 21 keV. The results detail how the pair distribution function (PDF) is affected by Q max , absorption and counting time duration at the PD beamline, and refined structural parameters exemplify how the PDF is affected by these parameters. There are considerations when performing total scattering experiments at the PD beamline, including (1) samples need to be stable during data collection, (2) highly absorbing samples with a μR > 1 always require dilution and (3) only correlation length differences >0.35 Å may be resolved. A case study comparing the PDF atom-atom correlation lengths with EXAFS-derived radial distances of Ni and Pt nanocrystals is also presented, which shows good agreement between the two techniques. The results here can be used as a guide for researchers considering total scattering experiments at the PD beamline or similarly setup beamlines., (open access.)

Introduction: Patients taking warfarin require frequent international normalized ratio (INR) monitoring in healthcare settings, putting them at increased risk of Coronavirus disease 2019 (COVID-19) exposure during the pandemic. Thus, strategies to limit in-person visits to healthcare facilities were recommended by the Anticoagulation Forum. The objective of this study was to describe the number and types of changes made to anticoagulation therapy as a result of pharmacist intervention during the COVID-19 pandemic., Materials and Methods: A retrospective chart review of patients included in a primary care COVID-19 anticoagulation intervention was conducted. During this intervention, pharmacists provided individualized recommendations for anticoagulation changes in patients taking warfarin to limit their healthcare facility exposure while also maintaining safe anticoagulation management practices., Results: As a result of pharmacist intervention, 83 (55.7 %) of the 149 patients included in the intervention had changes in anticoagulation including: switching to a direct oral anticoagulant (n = 12), extending the INR monitoring interval (n = 48), switching to home INR monitoring (n = 21), or stopping anticoagulation (n = 2). For those patients who were taking warfarin for the entire 6 months pre- and post-intervention, the total number of healthcare facility and laboratory visits with an INR completed decreased from 8.8 to 6.4 (p < 0.001) per patient without a statistically significant decrease in time in therapeutic range (p = 0.76)., Conclusions: This study depicts rapid implementation of a population health-based approach to assess all patients taking warfarin for options to minimize healthcare visits and decrease risk for COVID-19 exposure. Methods to reduce healthcare visit burden while maintaining patient safety should be considered as a regular component of anticoagulation management post-pandemic., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The morphology of organic semiconductors is critical to their function in optoelectronic devices and is particularly crucial in the donor-acceptor mixture that comprises the bulk heterojunction of organic solar cells. Here, energy landscapes can play integral roles in charge photogeneration, and recently have been shown to drive the accumulation of charge carriers away from the interface, resulting in the buildup of large nanoscale electric fields, much like a capacitor. In this work we combine morphological and spectroscopic data to outline the requirements for this interdomain charge accumulation, finding that this effect is driven by a three-phase morphology that creates an energetic cascade for charge carriers. By adjusting annealing conditions, we show that domain purity, but not size, is critical for an electro-absorption feature to grow-in. This demonstrates that the energy landscape around the interface shapes the movement of charges and that pure domains are required for charge carrier buildup that results in reduced recombination and large interdomain nanoscale electric fields.

Controlling the nanoscale morphology of the photoactive layer by fine-tuning the molecular structure of semiconducting organic materials is one of the most effective ways to improve the power conversion efficiency of organic solar cells. In this contribution, we investigate the photovoltaic performance of benzodithiophene (BDT)-based p-type small molecules with three different side chains, namely alkyl-thio (BTR-TE), dialkylthienyl (BTR), and trialkylsilyl (BTR-TIPS) moieties substituted on the BDT core, when used alongside a nonfullerene acceptor. The side-chain changes on the BDT core are shown to have a profound effect on energy levels, charge generation, recombination, morphology, and photovoltaic performance of solid-state molecules. Compared with BTR and BTR-TIPS, BTR-TE-based single-junction binary blend solar cells show the best power conversion efficiency (PCE) of 13.2% due to improved morphology and charge transport with suppressed recombination. In addition, we also achieved relatively good performances for ternary blend solar cells with a PCE of 16.1% using BTR-TE as a third component. Our results show that side-chain modification has a significant effect on modulating active layer morphology, and in particular that thioether side-chain modification is an effective way to achieve optimum morphology and performance for organic photovoltaic (OPV) devices.

Organic photovoltaic (OPV) efficiencies continue to rise, raising their prospects for solar energy conversion. However, researchers have long considered how to suppress the loss of free carriers by recombination-poor diffusion and significant Coulombic attraction can cause electrons and holes to encounter each other at interfaces close to where they were photogenerated. Using femtosecond transient spectroscopies, we report the nanosecond grow-in of a large transient Stark effect, caused by nanoscale electric fields of ∼487 kV/cm between photogenerated free carriers in the device active layer. We find that particular morphologies of the active layer lead to an energetic cascade for charge carriers, suppressing pathways to recombination, which is ∼2000 times less than predicted by Langevin theory. This in turn leads to the buildup of electric charge in donor and acceptor domains-away from the interface-resistant to bimolecular recombination. Interestingly, this signal is only experimentally obvious in thick films due to the different scaling of electroabsorption and photoinduced absorption signals in transient absorption spectroscopy. Rather than inhibiting device performance, we show that devices up to 600 nm thick maintain efficiencies of >8% because domains can afford much higher carrier densities. These observations suggest that with particular nanoscale morphologies the bulk heterojunction can go beyond its established role in charge photogeneration and can act as a capacitor, where adjacent free charges are held away from the interface and can be protected from bimolecular recombination.

Synthesis of fluorene-based conjugated polyelectrolytes was achieved via Suzuki polycondensation in water and completely open to air. The polyelectrolytes were conveniently purified by dialysis and analysis of the materials showed properties expected for fluorene-based conjugated polyelectrolytes. The materials were then employed in solar cell devices as an interlayer in conjunction with ZnO. The double interlayer led to enhanced power conversion efficiency of 10.75 % and 15.1 % for polymer and perovskite solar cells, respectively., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The efficient production of biofuels from cellulosic feedstocks will require the efficient fermentation of the sugars in hydrolyzed plant material. Unfortunately, plant hydrolysates also contain many compounds that inhibit microbial growth and fermentation. We used DNA-barcoded mutant libraries to identify genes that are important for hydrolysate tolerance in both Zymomonas mobilis (44 genes) and Saccharomyces cerevisiae (99 genes). Overexpression of a Z. mobilis tolerance gene of unknown function (ZMO1875) improved its specific ethanol productivity 2.4-fold in the presence of miscanthus hydrolysate. However, a mixture of 37 hydrolysate-derived inhibitors was not sufficient to explain the fitness profile of plant hydrolysate. To deconstruct the fitness profile of hydrolysate, we profiled the 37 inhibitors against a library of Z. mobilis mutants and we modeled fitness in hydrolysate as a mixture of fitness in its components. By examining outliers in this model, we identified methylglyoxal as a previously unknown component of hydrolysate. Our work provides a general strategy to dissect how microbes respond to a complex chemical stress and should enable further engineering of hydrolysate tolerance.

Purpose: The purpose of the study was to evaluate insulin injection technique and storage of insulin pens as reported by patients with diabetes and to compare correct pen use to initial education on injection technique, hemoglobin A1C, duration of insulin therapy, and duration of insulin pen., Methods: Cross-sectional questionnaire orally administered to patients at a university-affiliated primary care practice. Subjects were patients with diabetes who were 18 years or older and prescribed a disposable insulin pen for at least 4 weeks. A correct usage score was calculated for each patient based on manufacturer recommendations for disposable insulin pen use. Associations were made between the correct usage score and certainty in technique, initial education, years of insulin therapy, duration of pen use, and hemoglobin A1C., Results: Sixty-seven patients completed the questionnaire, reporting total use of 94 insulin pens. The 3 components most often neglected by patients were priming pen needle, holding for specific count time before withdrawal of pen needle from skin, and storing an in-use pen. For three-fourths of the insulin pens being used, users did not follow the manufacturer's instructions for proper administration and storage of insulin pens. Correct usage scores were significantly higher if initial education on insulin pens was performed by a pharmacist or nurse., Conclusions: The majority of patients may be ignoring or unaware of key components for consistent insulin dosing using disposable insulin pens; therefore, initial education and reeducation on correct use of disposable insulin pens by health care professionals are needed.

Miscanthus giganteus lignin was extracted by an organosolv process under reflux conditions (4 h) with varying concentrations of ethanol (65%, 75%, 85%, 95%) and 0.2 M hydrochloric acid as catalyst. The resulting lignin was extensively characterized by size exclusion chromatography (SEC), Fourier-transform infrared spectroscopy (FTIR), gas chromatography-mass spectrometry (GC/MS), two-dimensional nuclear magnetic resonance spectroscopy (2D-NMR), and chemical analysis (residual sugars, Klason lignin, ash). The predominant linkage units present were β-O-4' (82-84%), resinol (6-7%), and phenylcoumaran (10-11%). The 65% ethanol solvent system gave the lowest lignin yield (14% of starting biomass) compared to 29-32% of the other systems. Increasing ethanol concentration resulted in decreasing carbohydrate content of the lignins (3.6-1.1%), a higher solubility in tetrahydrofuran (THF), a slight reduction of the molecular weight (M(w) 2.72-2.25 KDa), an increasing α-ethoxylation, and an increase in ethoxylated phenylpropenoic compounds (p-coumaric and ferulic acid), but the S/G ratio of the monolignols (0.63, GC/MS) and Klason lignin content (86-88%) were unaffected. An extraction method for these ethyl-esterified phenylpropenoids and smaller molecular weight lignin compounds was developed. The effect of reaction time (2, 4, and 8 h) was investigated for the 95% ethanol solvent system. Besides increased lignin yield (13-43%), a slight increase in M(w) (2.21-2.38 kDa) and S/G ratio (0.53-0.68, GC-MS) was observed. Consecutive extractions suggested that these changes were not from lignin modifications (e.g., condensations) but rather from extraction of lignin of different composition. The results were compared to similar solvent systems with 95% acetone and 95% dioxane.

Dimethylnitrosamine (DMN) was mutagenic in the Salmonella plate incorporation assay (Ames test) at a level of 10 mumol/plate (3.7 mM) in the presence of hamster liver S-9. Mutagenicity of DMN at this level was not observed when the S-9 was derived from mouse or rat liver, although the mouse liver and hamster liver S-9 had similar DMN demethylase activities. Both mouse and rat liver S-9 inhibited the mutagenicity of DMN mediated by hamster liver S-9; the inhibitory factor was contained in the microsomal fraction. Mouse or rat liver microsomes did not inhibit the DMN demethylase activity of hamster liver S-9. The microsomal inhibitor from rat or mouse liver was stable at 60 but was inactivated at 70 degrees. DMN demethylase from both rat and mouse liver was inactivated at 60 degrees. Although the DMN demethylase activity of hamster liver S-9 was contained in the microsomal fraction, DMN mutagenesis under conditions of the assay required the presence of both microsomal and cytosolic (S-105) fractions; the cytosols from hamsters, mice, and rats were all effective. The cytosolic factor required for DMN mutagenesis was sensitive to trypsin and was not dialyzable. The presence of an inhibitor of DMN activation in rat and mouse microsomes may account for, or contribute to, the failure of liver S-9 preparations from these species to activate DMN to a mutagen under standard conditions of the Ames test. The requirement for the cytosolic fraction may indicate that DMN demethylase is not sufficient for the activation of DMN to a mutagen under the conditions used in these studies.

An ingredient recently introduced in hair dyes, 4-ethoxy-m-phenylenediamine, is mutagenic in histidine-requiring strains of Salmonella typhimurium. Its mutagenic activity is similar to that of the hair dye ingredient is apparently replaced, 4-methoxy-m-phenylenediamine.

We have evaluated the mutagenic activity of a series of diazo compounds derived from benzidine and its congeners o-tolidine, o-dianisidine and 3,3'-dichlorobenzidine as well as several monoazo compounds. The test system used was a modification of the standard Ames Salmonella assay in which FMN, hamster liver S9 and a preincubation step are used to facilitate azo reduction and detection of the resulting mutagenic aromatic amines. All of the benzidine and o-tolidine dyes tested were clearly mutagenic. The o-dianisidine dyes except for Direct Blue 218 were also mutagenic. Direct Blue 218 is a copper complex of the mutagenic o-dianisidine dye Direct Blue 15. Pigment Yellow 12, which is derived from 3,3'-dichlorobenzidine, could not be detected as mutagenic, presumably because of its lack of solubility in the test reaction mixture. Of the monoazo dyes tested, methyl orange was clearly mutagenic, while C.I. Acid Red 26 and Acid Dye (C.I. 16155; often referred to as Ponceau 3R) had marginal to weak mutagenic activity. Several commercial dye samples had greater mutagenic activity with the modified test protocol than did equimolar quantities of their mutagenic aromatic amine reduction products. Investigation of this phenomenon for Direct Black 38 and trypan blue showed that it was due to the presence of mutagenic impurities in these samples. The modified method used appears to be suitable for testing the mutagenicity of azo dyes, and it may also be useful for monitoring the presence of mutagenic or potentially carcinogenic impurities in otherwise nonmutagenic azo dyes.

A protocol for assessing the mutagenic activity of azo dyes derived from mutagenic or potentially mutagenic aromatic amines was evaluated, using 4 model compounds. This protocol is based upon one developed in Sugimura's laboratory with modifications, including the use of flavin mononucleotide (FMN) rather than riboflavin to reduce the azo compounds to free amines, and hamster liver S9 rather then rat liver S9 for metabolic activation. The protocol developed differs from the standard Ames Salmonella plate incorporation assay in 5 ways: (1) uninduced hamster liver S9 rather than Aroclor 1254-induced rat liver S9 is used; (2) 150 microliters of S9 is used rather than the maximum of 50 microliter of S9 used in the standard assay; (3) FMN is added to the cofactor mix; (4) the cofactor mix is modified to include exogenous glucose 6-phosphate dehydrogenase, NADH, and 4 times the standard amount of glucose 6-phosphate; and (5) a 30-min "pre-incubation" step is used before addition of top agar. We found that each of these 5 changes is necessary for optimal mutagenic activity of azo dyes derived from the mutagenic aromatic amines benzidine, o-tolidine or o-dianisidine. The use of hamster liver S9 rather than rat liver S9 was also required for optimal mutagenic activity of benzidine itself. Rat liver S9 inhibited the ability of hamster S9 to activate benzidine to a mutagen. The presence in rat liver S9 of an inhibitor of the metabolic activation of benzidine may account for the failure of benzidine and a benzidine dye (Congo red) to be strongly mutagenic when tested with this type of S9.