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SOLID phase extraction, PULMONARY surfactant, ANALYTICAL chemistry, SURFACE active agents, PREMATURE infants, and DENSITY functional theory

• A mixed mode DSPE approach was developed using organic polymers. • The method was used to lung surfactants determination in EBC samples. • Density functional theory calculations were used to show the nature of the chemical interactions. • Simplex centroid experimental design was used for optimization of the sorbent composition. A mixed mode dispersive solid phase extraction method was introduced for the extraction of three lung surfactants from exhaled breath condensate samples. Considering the trends to green analytical chemistry, organic polymers including polystyrene (PS), polymethylmethacrylate (PMMA-15 K), and polymethylmethacrylate (PMMA-45 K) were utilized as the sorbent for extraction of the analytes. The extraction capability for each polymer toward the studied analytes was evaluated using simplex centroid design. Based on the results, a mixture of sorbents consisting of PS, PMMA-15 K, and PMMA-45 K mixture with the mass ratio of 1:2:1: w/w/w was selected as the suitable sorbent. The effective parameters influencing the method's efficiency were investigated and optimized. Based on the figure of merit for the developed method, the calibration curves were linear in the concentration range of 0.76–1000 ng mL–1 and limits of detection were from 0.09 to 0.19 ng mL–1. The method repeatability was investigated at three concentrations as inter- and intra-day precisions and the obtained data showed that they were in the ranges of 5.2–9.1 and 4.2–8.9%, respectively. The enrichment factors were in the range of 88–100. The developed method was successfully employed in the analysis of the surfactants in the exhaled breath samples of three premature infants collected from the expiratory circuits of the mechanical ventilators. The nature of the chemical interactions with PMMA-PS complex system of the surfactants was investigated through Density Functional Theory calculations. Calculated binding energies showed that PMMA-PS complex system exhibit high performance in the extraction of lung surfactants. The most powerful interaction is between PMMA-PS complex system and 1-palmitoyl-2-oleoylsn‑glycero-3-phosphocholine. [ABSTRACT FROM AUTHOR]

INDUCTIVELY coupled plasma mass spectrometry, PORITES, X-ray spectroscopy, CORALS, INDUCTIVELY coupled plasma atomic emission spectrometry, and BIOGEOCHEMICAL cycles

Coral skeletal P/Ca ratio has been developed as an indicator of temporal seawater dissolved inorganic phosphorus (DIP). The use of coral P/Ca proxy helps to assess oceanographic and climatic impacts such as upwelling, circulation, and continent runoffs on marine biogeochemical cycles. However, factors controlling skeletal P incorporation and elemental partitioning between seawater and coral skeletons remain elusive. We conducted temperature-controlled (∼21 to 29 °C) aquaria culture experiments using two colonies of Porites australiensis corals (here refer to B and C) with the only difference in zooxanthellae density (B > C). The coral growth rate ranges from 9.4 to 19.4 mg/day (B) and 0.7 to 14.1 mg/day (C). Only the growth rate of colony C significantly correlates to temperature, potentially reflecting physiological controls on the two colonies given the difference in the zooxanthellae density. We measured coral P/Ca ratios by Inductively coupled plasma mass spectrometry and determined skeletal P speciation through a synchrotron-based spectroscopic approach. Coral P/Ca ratio ranges from 6.5 to 18.6 μmol/mol (B) and 7.2 to 19.8 μmol/mol (C). The dominance of organic-P is confirmed, and the presence of inorganic-P cannot be excluded. Only colony C has a strong P/Ca dependence on temperature and both colonies show strong correlations between P/Ca and growth rate. Although growth rate and temperature are intercorrelated, the growth rate is more likely the direct controlling factor on coral P/Ca in our experiments. Combined laboratory data with field observations, we suggest that the validity of the Porites P/Ca proxy may be influenced by seawater DIP, coral species, and growth rate. • Cultured coral P/Ca ratio can be variable with relatively constant seawater chemistry. • Organic phosphorus is widely present in coral skeletons despite oxidative cleaning. • The validity of the P/Ca proxy could be influenced by seawater DIP, coral species, and growth rate. [ABSTRACT FROM AUTHOR]

Radical Ring‐opening polymerization (RROP) of cyclic ketene acetals (CKAs) emerges to be a valuable polymerization technique. In attracting more attention, RROP has seen a new spike in publications, which the authors will put into perspective. This review will hence address the progress made on the number of available CKAs and the synthetic strategies to get them. In grouping, the available monomers into distinct categories, the enormous variety of available CKAs will be highlighted. Polymerizations of CKAs without vinylenes have the potential to yield fully biodegradable polymers, which is why this kind of polymerization is the focus of this review. Detailing the current understanding of the mechanism, the various side reactions will be noted and also their effect on the overall properties of the final polymers. Current attempts to control the ring‐retaining and branching reactions will be discussed as well. In addition to the polymerization itself, the available materials will be discussed as well as homopolymers, copolymers of CKAs, and block‐copolymers with pure CKA‐blocks have significantly widened the range of possible applications of materials from RROP. Altogether this review highlights the progress in the entire field of RROP just of CKAs to give a holistic overview of the field. [ABSTRACT FROM AUTHOR]

CONFERENCES & conventions, ANTIVIRAL agents, CAREER development, VACCINE development, SCIENTIFIC community, and INFORMATION sharing

The 35th International Conference on Antiviral Research (ICAR), sponsored by the International Society for Antiviral Research (ISAR), was held in Seattle, Washington, USA, on March 21–25, 2022 and concurrently through an interactive remote meeting platform. This report gives an overview of the conference on behalf of the society. It provides a general review of the meeting and awardees, summarizing the presentations and their main conclusions from the perspective of researchers active in many different areas of antiviral research and development. Through ICAR, leaders in the field of antiviral research were able to showcase their efforts, as participants learned about key advances in the field. The impact of these efforts was exemplified by many presentations on SARS-CoV-2 demonstrating the remarkable response to the ongoing pandemic, as well as future pandemic preparedness, by members of the antiviral research community. As we address ongoing outbreaks and seek to mitigate those in the future, this meeting continues to support outstanding opportunities for the exchange of knowledge and expertise while fostering cross-disciplinary collaborations in therapeutic and vaccine development. The 36th ICAR will be held in Lyon, France, March 13–17, 2023. • This report summarizes presentations at the 35th International Conference on Antiviral Research. • This meeting used a hybrid model with in-person sessions in Seattle, WA, USA, and concurrent live virtual sessions. • Meeting sessions covered the treatment of a wide variety of viruses, pandemic preparedness, and other topics. • Plenary lectures focused on the role of foundations in antiviral development, pandemic preparedness and other key concepts. • The meeting also featured special sessions and events, late-breaking oral presentations, and a career development workshop. [ABSTRACT FROM AUTHOR]

HETEROGENEOUS catalysts, UNSATURATED compounds, DECOMPOSITION method, ETHANOL, AROMATIC aldehydes, CALCITE, and OXINDOLES

[Display omitted] • CaCO 3 nanoflowers (NFs) were synthesized by the thermal decomposition method. • Knoevenagel condensation of 2-oxindole has been investigated using Calcite NFs first time. • The higher catalytic activity of NFs is due to the size, surface area, and hollow, sheet-like structures of flower petals. • According to the findings, the technique is far more cost-effective and has a lower environmental toxicity impact. • The catalyst could be recycled without significantly decreasing reactivity until five cycles. α-β unsaturated heterocyclic compounds such as C3-arylidene-oxindoles, with five-member rings containing nitrogen, have an important role in the realm of medicine. This study aims to synthesize the C3-arylindene-oxindoles derivative compounds using calcite nanoflowers (CaCO 3 NFs) as a heterogeneous catalyst for the first time. These CaCO 3 NFs prepared by the thermal decomposition method, which is an active and reusable catalyst for stereospecific Knoevenagel condensation reaction between 2-oxindole and aromatic aldehyde under different solvent conditions like water, ethyl alcohol, and 50 % aqueous ethyl alcohol. This catalytic method is employed with a wide range of aromatic aldehydes to produce high yields of C3-arylidene-oxindoles (93–99 %), with stereo-specifically E -isomers (100 %) for 50 % alcohol and alcohol as a solvent. [ABSTRACT FROM AUTHOR]

Glioblastoma multiforme (GBM) is a highly‐aggressive, dreadful disease with poor prognosis and disappointing clinical success. There is an unmet medical need of molecularly‐targeted therapeutics for GBM treatment. In the present work, a series of novel 2‐phenyl‐substituted 4‐amino–6,7‐dihydro‐5H‐cyclopenta[d]pyrimidines was designed, synthesized, purified, characterized, and evaluated for cytotoxicity against glioblastoma cell line U87‐MG. The design process (virtual library enumeration around the core, physicochemical and molecular property prediction/calculation of the designs, filtering the undesirable ones, and the diversity analyses of the lead‐like designs), was carefully curated so as to obtain a set of structurally‐diverse, novel molecules (total 20), with a particular focus on the relatively unexplored core structure, 6,7‐dihydro‐5H‐cyclopenta[d]pyrimidine. The preliminary screening was done using MTT assay at 10 and 100 μM concentrations of the title compounds F1−F20 and positive control cisplatin, which yielded six hits (% inhibition at 10 μM: ~50%)—F2, F3, F5, F7, F15, and F20, which were taken up for IC50 determination. The top hits F2 and F7 (IC50 < 10 μM) were further used for computational studies such as target prediction, followed by their molecular docking in the binding sites of the top‐3 predicted targets (epidermal growth factor receptor kinase domain, cyclin‐dependent kinase 2 [CDK2]) /cyclin E, and anaplastic lymphoma kinase [ALK]). The docking pose analyses revealed interesting trends. The relatively planar core structure, presence of favorable hinge‐binding substructures, basic groups, all added up, and culminated in appreciable cytotoxicity against GBM cell line. [ABSTRACT FROM AUTHOR]

SMALL molecules, STYRENE, ALKENES, FATTY acids, and ALCOHOL

Enantioselective synthesis of chiral alcohols through asymmetric addition of water across an unactivated alkene is a highly sought‐after transformation and a big challenge in catalysis. Herein we report the identification and directed evolution of a fatty acid hydratase from Marinitoga hydrogenitolerans for the highly enantioselective hydration of styrenes to yield chiral 1‐arylethanols. While directed evolution for styrene hydration was performed in the presence of heptanoic acid to mimic fatty acid binding, the engineered enzyme displayed remarkable asymmetric styrene hydration activity in the absence of the small molecule activator. The evolved styrene hydratase provided access to chiral alcohols from simple alkenes and water with high enantioselectivity (>99 : 1 e.r.) and could be applied on a preparative scale. [ABSTRACT FROM AUTHOR]

SMALL molecules, STYRENE, ALKENES, FATTY acids, and ALCOHOL

Enantioselective synthesis of chiral alcohols through asymmetric addition of water across an unactivated alkene is a highly sought‐after transformation and a big challenge in catalysis. Herein we report the identification and directed evolution of a fatty acid hydratase from Marinitoga hydrogenitolerans for the highly enantioselective hydration of styrenes to yield chiral 1‐arylethanols. While directed evolution for styrene hydration was performed in the presence of heptanoic acid to mimic fatty acid binding, the engineered enzyme displayed remarkable asymmetric styrene hydration activity in the absence of the small molecule activator. The evolved styrene hydratase provided access to chiral alcohols from simple alkenes and water with high enantioselectivity (>99 : 1 e.r.) and could be applied on a preparative scale. [ABSTRACT FROM AUTHOR]

ENZYME stability, THERAPEUTIC immobilization, AMINOTRANSFERASES, KINETIC resolution, BIOCATALYSIS, ENZYMES, and AMINE oxidase

Biocatalytic syntheses often require unfavorable conditions, which can adversely affect enzyme stability. Consequently, improving the stability of biocatalysts is needed, and this is often achieved by immobilization. In this study, we aimed to compare the stability of soluble and immobilized transaminases from different species. A cysteine in a consensus sequence was converted to a single aldehyde by the formylglycine-generating enzyme for directed single-point attachment to amine beads. This immobilization was compared to cross-linked enzyme aggregates (CLEAs) and multipoint attachments to glutaraldehyde-functionalized amine- and epoxy-beads. Subsequently, the reactivity and stability (i.e., thermal, storage, and solvent stability) of all soluble and immobilized transaminases were analyzed and compared under different conditions. The effect of immobilization was highly dependent on the type of enzyme, the immobilization strategy, and the application itself, with no superior immobilization technique identified. Immobilization of HAGA-beads often resulted in the highest activities of up to 62 U/g beads, and amine beads were best for the hexameric transaminase from Luminiphilus syltensis. Furthermore, the immobilization of transaminases enabled its reusability for at least 10 cycles, while maintaining full or high activity. Upscaled kinetic resolutions (partially performed in a SpinChemTM reactor) resulted in a high conversion, maintained enantioselectivity, and high product yields, demonstrating their applicability. [ABSTRACT FROM AUTHOR]

HYDROGELS, ELASTICITY, INCLUSION compounds, CHEMICAL structure, POLYMER networks, DOUBLE bonds, MACROMONOMERS, and POLYACRYLAMIDE

Smart hydrogels are interesting materials as they can change their dimensions upon an external trigger. Herein, a photoresponsive double cross‐linked hydrogel system based on polyacrylamide (AAm) with grafted poly(2‐methyl‐2‐oxazoline) (PMOXA) chains with a α‐cyclodextrin/azobenzene host–guest complex is present. Switching azobenzene from the trans to the cis‐conformation through irradiation with UV light breaks the complex reversibly. Well‐defined PMOXA macromonomers have been synthesized and functionalized with the respective host and guest functionalities as well as double bonds for the incorporation into the polymer network as grafted side chains. The chemical structure of the macromonomers and the complex is confirmed by 1H NMR, 2D NOESY NMR, GPC, and UV–VIS measurements. Hydrogels with different ratios of permanent and photoresponsive cross‐linkers as well as different chain lengths of the PMOXA macromonomers are analyzed toward differences in their swelling/deswelling and elastic properties. Successive irradiation of supramolecular hydrogels with UV and VIS light allowed for a repeated swelling and de‐swelling of the hydrogels. This system is studied at both macro and micro scales, showing similar swelling tendencies. The tuned properties of photoresponsive double cross‐linked hydrogel makes this system a promising tool for various applications, for example, as in situ controllable valves in microfluidic flow cells. [ABSTRACT FROM AUTHOR]