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RSC Sustainability Feb 2024Two new water-soluble cellulose derivatives were prepared by a two-step transformation with 1,3-propane sultone, followed by either maleic or succinic anhydride, thereby...
Two new water-soluble cellulose derivatives were prepared by a two-step transformation with 1,3-propane sultone, followed by either maleic or succinic anhydride, thereby converting cellulose into a more easily processable form. It was found that the solubility was dependent on both the degree of substitution and the chemical properties of the substituents. The water-soluble cellulose has a molecular weight greater than 100 000 g mol and both the morphology and molecular weight can be tuned by varying the reaction conditions. Furthermore, the flexible, two-step nature of the process allows for expansion of this methodology in order to prepare cellulose analogues for different applications.
PubMed: 38333579
DOI: 10.1039/d3su00317e -
Scientific Reports Feb 2024Nitrogen oxides (NOx) are one of the growing air pollutants in industrial countries, and their emissions are regulated by stringent legislation. Therefore, the design of...
Nitrogen oxides (NOx) are one of the growing air pollutants in industrial countries, and their emissions are regulated by stringent legislation. Therefore, the design of the catalyst comprised of metal oxides and ZIFs a potential solution for improving selective catalytic reduction (SCR) of NOx. Here, an efficient strategy was described to fabricate Co-ZIF/WO heterostructures for SCR of NOx. First, WO nanostructures were fabricated by the solvothermal method, and subsequently epitaxial growth of ZIF-67 on the metal oxide surface to create a new type of semiconductor Co-ZIF/WO heterostructures. The obtained heterostructures were systemically characterized by wide-angle XRD, FESEM, UV DRS, FT-IR, AFM, and TEM spectroscopies. The Co-ZIF/WO heterostructures shift the temperature corresponding to the maximum conversion around 50 °C towards lower temperatures. The maximum conversion is substantially enhanced from 55% at 400 °C to 78% at 350 °C. The enhanced activity is attributed to better interaction and synergic effect of WO incorporated into ZIF-67 and also the electron transfer facility between the WO and Co species in Co-ZIF/WO heterostructures. Moreover, Co-ZIF/WO results in a distinct effect on the production of carbon monoxide (CO) in the product gas stream. The current study highlights some of the challenges in the development of semiconductor-based heterostructures for a decrease in air pollution.
PubMed: 38332032
DOI: 10.1038/s41598-024-53805-7 -
Computational and Structural... Dec 2024Liposomes, nanoscale spherical structures composed of amphiphilic lipids, hold great promise for various pharmaceutical applications, especially as nanocarriers in...
Liposomes, nanoscale spherical structures composed of amphiphilic lipids, hold great promise for various pharmaceutical applications, especially as nanocarriers in targeted drug delivery, due to their biocompatibility, biodegradability, and low immunogenicity. Understanding the factors influencing their physicochemical properties is crucial for designing and optimizing liposomes. In this study, we have presented the kernel-weighted local polynomial regression (KwLPR) nano-quantitative structure-property relationships (nano-QSPR) model to predict the zeta potential (ZP) based on the structure of 12 liposome formulations, including 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), 3ß-[N-(N',N'-dimethylaminoethane)-carbamoyl]cholesterol (DC-Chol), 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), and L-α-phosphatidylcholine (EPC). The developed model is well-fitted ( = 0.96, = 5.76), flexible ( = 0.83, = 10.77), and reliable (= 0.89 = 5.17). Furthermore, we have established the formula for computing molecular nanodescriptors for liposomes, based on constituent lipids' molar fractions. Through the correlation matrix and principal component analysis (PCA), we have identified two key structural features affecting liposomes' zeta potential: hydrophilic-lipophilic balance (HLB) and enthalpy of formation. Lower HLB values, indicating a more lipophilic nature, are associated with a higher zeta potential, and thus stability. Higher enthalpy of formation reflects reduced zeta potential and decreased stability of liposomes. We have demonstrated that the nano-QSPR approach allows for a better understanding of how the composition and molecular structure of liposomes affect their zeta potential, filling a gap in ZP nano-QSPR modeling methodologies for nanomaterials (NMs). The proposed proof-of-concept study is the first step in developing a comprehensive and computationally based system for predicting the physicochemical properties of liposomes as one of the most important drug nano-vehicles.
PubMed: 38328349
DOI: 10.1016/j.csbj.2024.01.012 -
Nature Communications Jan 2024The oxidative dehydrogenation of propane, primarily sourced from shale gas, holds promise in meeting the surging global demand for propylene. However, this process...
The oxidative dehydrogenation of propane, primarily sourced from shale gas, holds promise in meeting the surging global demand for propylene. However, this process necessitates high operating temperatures, which amplifies safety concerns in its application due to the use of mixed propane and oxygen. Moreover, these elevated temperatures may heighten the risk of overoxidation, leading to carbon dioxide formation. Here we introduce a microchannel reaction system designed for the oxidative dehydrogenation of propane within an aqueous environment, enabling highly selective and active propylene production at room temperature and ambient pressure with mitigated safety risks. A propylene selectivity of over 92% and production rate of 19.57 mmol m h are simultaneously achieved. This exceptional performance stems from the in situ creation of a highly active, oxygen-containing Cu catalytic surface for propane activation, and the enhanced propane transfer via an enlarged gas-liquid interfacial area and a reduced diffusion path by establishing a gas-liquid Taylor flow using a custom-made T-junction microdevice. This microchannel reaction system offers an appealing approach to accelerate gas-liquid-solid reactions limited by the solubility of gaseous reactant.
PubMed: 38287034
DOI: 10.1038/s41467-024-45179-1 -
Cureus Dec 2023A 35-year-old male patient, a farmer by occupation, presented with a complaint of deviation of the angle of the mouth towards the right side while speaking. A...
A 35-year-old male patient, a farmer by occupation, presented with a complaint of deviation of the angle of the mouth towards the right side while speaking. A cerebrovascular event was suspected in this patient. He had a history of exposure to propane and cypermethrin while spraying insecticide in his field. He has a history of chronic exposure to these compounds. Intermediate syndrome (IMS) also known as type II syndrome was diagnosed in this patient with the help of neuroimaging. On evaluation, the patient was found to be having oromandibular dystonia, which is an extrapyramidal symptom of type II syndrome.
PubMed: 38283511
DOI: 10.7759/cureus.51137 -
Molecules (Basel, Switzerland) Jan 2024In the process of systematically studying the methylhydroxyiminoethaneamide -chelate ligands with polymethylene spacers of different lengths, L1-L3, and their transition...
In the process of systematically studying the methylhydroxyiminoethaneamide -chelate ligands with polymethylene spacers of different lengths, L1-L3, and their transition metal complexes, a number of new Ni(II) and Cu(II) species have been isolated, and their molecular and crystal structures were determined using single-crystal X-ray diffraction. In all of these compounds, the divalent metal is coordinated by the ligand donor atoms in a square-planar arrangement. In addition, a serendipitously discovered new type of neutral Ni(II) complex, where the propane spacer of ligand L2 underwent oxidation to the propene spacer, and one of the amide groups was oxidised to the ketoimine, is also reported. The resulting ligand L2' affords the formation of neutral planar Ni(II) complexes, which are assembled in the solid state on top of each other, and yield two polymorphic structures. In both structures, the resulting infinite, exclusively parallel metal ion columns in ligand insulation may serve as precursor materials for sub-nano-conducting connectors. Overall, this paper reports the synthesis and characterisation of seven new anionic, cationic, and neutral Ni(II) and Cu(II) complexes, their crystal structures, as well as experimental and computed UV-Vis absorption spectra for two structurally similar Ni(II) complexes, yellow and red.
PubMed: 38276599
DOI: 10.3390/molecules29020522 -
Food Chemistry: X Mar 2024This study developed a novel and green method to produce fragrant sesame oil using microwaves and subcritical extraction (SBE). Sesame seeds were microwaved at 540 W...
This study developed a novel and green method to produce fragrant sesame oil using microwaves and subcritical extraction (SBE). Sesame seeds were microwaved at 540 W for 0-9 min before subcritical propane extraction at 40 °C and 0.5 MPa. SBE caused less deformation to the cellular microstructure of sesame cotyledons while dramatically improving oil yield (96.7-97.1 %) compared to screw processing (SP) (53.1-58.6 %). SBE improved extraction rates for γ-tocopherol (381.1-454.9 μg/g) and sesame lignans (917.9-970.4 mg/100 g) in sesame oil compared to SP (360.1-443.8 μg/g and 872.8-916.8 mg/100 g, respectively). Microwaves generated aroma-active heterocyclics and phenolics faster than hot-air roasting in sesame oil with a better sensory profile. SBE had a higher extraction rate for aroma-active terpenes, alcohols, and esters while reducing the concentrations of carcinogenic PAHs and HCAs in sesame oil. The novel combination process of microwaves and subcritical extraction is promising in producing fragrant sesame oil with superior qualities.
PubMed: 38268846
DOI: 10.1016/j.fochx.2023.101087 -
Organic Process Research & Development Jan 2024MMV693183 is a promising antimalarial drug candidate that works for uncomplicated malaria treatment and resistance management. Herein, we report an efficient and highly...
MMV693183 is a promising antimalarial drug candidate that works for uncomplicated malaria treatment and resistance management. Herein, we report an efficient and highly regioselective synthesis of MMV693183. This novel synthetic method highlights a three-step route with an overall yield of 46% from readily available starting materials. The key to the success lies in (1) utilizing the subtle difference of the two amino groups in the starting material ()-propane-1,2-diamine dihydrochloride without amino protection and (2) identifying the -(+)-tartaric acid as the counter acid for the organic salt formation, yielding the desired regioisomer up to 100:0. The efficient and scalable three-step protocol operates under mild conditions with a high chemo/regioselectivity, providing effective access to MMV693183.
PubMed: 38268773
DOI: 10.1021/acs.oprd.3c00353 -
Water Nov 2023This article provides an overview of the bioremediation of groundwater plumes containing admixtures of chlorinated volatile organic compounds (CVOCs) and 1,4-dioxane....
This article provides an overview of the bioremediation of groundwater plumes containing admixtures of chlorinated volatile organic compounds (CVOCs) and 1,4-dioxane. The remediation of these plumes has historically focused on the reductive dechlorination of the CVOCs. Many of the remaining plumes are relatively large, and contaminant concentrations are diluted below the concentrations that can sustain reductive dechlorination. Cometabolic processes can decrease contaminant concentrations below the thresholds needed to support direct metabolism but typically require the addition of a substrate, such as high-purity propane. Relatively intensive site characterization and monitoring is necessary to implement bioremediation.
PubMed: 38264201
DOI: 10.3390/w15223952 -
Microbial Physiology 2024Phocaeicola vulgatus (formerly Bacteroides vulgatus) is a prevalent member of human and animal guts, where it influences by its dietary-fiber-fueled, fermentative...
INTRODUCTION
Phocaeicola vulgatus (formerly Bacteroides vulgatus) is a prevalent member of human and animal guts, where it influences by its dietary-fiber-fueled, fermentative metabolism the microbial community as well as the host health. Moreover, the fermentative metabolism of P. vulgatus bears potential for a sustainable production of bulk chemicals. The aim of the present study was to refine the current understanding of the P. vulgatus physiology.
METHODS
P. vulgatus was adapted to anaerobic growth with 14 different carbohydrates, ranging from hexoses, pentoses, hemicellulose, via an uronic acid to deoxy sugars. These substrate-adapted cells formed the basis to define the growth stoichiometries by quantifying growth/fermentation parameters and to reconstruct the catabolic network by applying differential proteomics.
RESULTS
The determination of growth performance revealed, e.g., doubling times (h) from 1.39 (arabinose) to 14.26 (glucuronate), biomass yields (gCDW/mmolS) from 0.01 (fucose) to 0.27 (α-cyclodextrin), and ATP yields (m
M ATP/mM C) from 0.21 (rhamnose) to 0.60 (glucuronate/xylan). Furthermore, fermentation product spectra were determined, ranging from broad and balanced (with xylan: acetate, succinate, formate, and propanoate) to rather one sided (with rhamnose or fucose: mainly propane-1,2-diol). The fermentation network serving all tested compounds is composed of 56 proteins (all identified), with several peripheral reaction sequences formed with high substrate specificity (e.g., conversion of arabinose tod -xylulose-3-phosphate) implicating a fine-tuned regulation. By contrast, central modules (e.g., glycolysis or the reaction sequence from PEP to succinate) were constitutively formed. Extensive formation of propane-1,2-diol from rhamnose and fucose involves rhamnulokinase (RhaB), rhamnulose-1-phosphate kinase (RhaD), and lactaldehyde reductase (FucO). Furthermore, Sus-like systems are apparently the most relevant uptake systems and a complex array of transmembrane electron-transfer systems (e.g., Na+-pumping Rnf and Nqr complexes, fumarate reductase) as well as F- and V-type ATP-synthases were detected.CONCLUSIONS
The present study provides insights into the potential contribution of P. vulgatus to the gut metabolome and into the strain's biotechnological potential for sustainable production of short-chain fatty acids and alcohols.
Topics: Fermentation; Proteomics; Bacterial Proteins; Gastrointestinal Microbiome; Anaerobiosis; Dietary Fiber; Humans; Bacteroidetes; Metabolic Networks and Pathways
PubMed: 38262373
DOI: 10.1159/000536327