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• The catalytic depolymerization of PET waste was achieved at low temperature. • More than 90 % of DET and EG yields were obtained. • The response surface methodology was utilized to optimize reaction conditions. • The 3Ni-ZnO/Al 2 O 3 catalyst demonstrated excellent stability over five cycles. Plastic waste poses a serious threat to the global environment, with recycled polyethylene terephthalate (PET) plastic accounting for a considerable portion. The application of supercritical ethanol depolymerization technology presents an effective method for recycling PET waste. This study investigated using Ni as an additive to enhance the catalytic activity of ZnO/Al 2 O 3 catalyst for PET waste depolymerization. The effects of different catalysts, catalyst dosage, reaction temperature, and reaction time on PET waste depolymerization were studied using the single-factor controlled variable method. The results showed that the 3Ni-ZnO/Al 2 O 3 was the optimal catalyst, and under the optimal conditions with catalyst dosage of 4 %, reaction temperature of 260 °C, and reaction time of 60 min, the depolymerization efficiency of PET waste could reach 100 %, with the highest yields of diethyl terephthalate (DET) and ethylene glycol (EG) of 93.6 % and 90.2 %, respectively. Response surface methodology (RSM) was used to optimize the operating conditions to obtain the highest monomer yields. The predicted optimal parameters from RSM were as follows: reaction temperature = 262.8 °C, reaction time = 63.2 min, catalyst dosage = 3.8 wt%, with the predicted highest DET and EG yields of 95.9 % and 90.7 %, respectively. The analysis of variance (ANOVA) results for DET and EG possessed the R2 values of 0.9921 and 0.9885, respectively, with p-values < 0.0001, indicating a good fit for the models. Furthermore, after five times reuse, the 3Ni-ZnO/Al 2 O 3 catalyst still exhibited good catalytic activity and stability. In conclusion, this study offers a clean, green, and sustainable alternative to recycling plastic waste. [ABSTRACT FROM AUTHOR]

Biomass valorisation through the selective oxidation of carbohydrate and lipid derivatives offers access to an array of platform chemicals through energy- and atom-efficient catalytic processes. Supported metal nanoparticles are promising catalysts for the aerobic selective oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA), but typically require strong liquid base to achieve high selectivity. Here, we explore the utility of MgO as a solid base support for the Ru-catalysed aerobic oxidation of HMF, obtaining 68% FDCA yield at 160°C and 1.5 MPa of O2 using <1 mol-% metal. Biomass offers a sustainable alternative source of carbon to existing fossil resources that underpin the global chemical industry – on which we rely for fuels, plastics and pharmaceuticals. Combining ruthenium metal with Earth-abundant magnesium oxide creates an efficient catalyst for transforming sugar components of waste biomass into a valuable precursor for the sustainable manufacture of plastics. (Image credit: Priya Lokhande.) This article belongs to the 10th Anniversary Collection of RACI and AAS Award papers. [ABSTRACT FROM AUTHOR]

The energetic metabolism of cancer cells relies on a substantial commitment of pyruvate to the catalytic action of lactate‐generating dehydrogenases. This coupling mainly depends on lactate dehydrogenase A (LDH‐A), which is overexpressed in different types of cancers, and therefore represents an appealing therapeutic target. Taking into account that the activity of LDHs is exclusively exerted by their tetrameric forms, it was recently shown that peptides perturbing the monomers‐to‐tetramer assembly inhibit human LDH‐A (hLDH‐A). However, to identify these peptides, tetrameric hLDH‐A was transiently exposed to strongly acidic conditions inducing its dissociation into monomers, which were tested as a target for peptides at low pH. Nevertheless, the availability of native monomeric hLDH‐A would allow performing similar screenings under physiological conditions. Here we report on the unprecedented isolation of recombinant monomeric hLDH‐A at neutral pH, and on its use to identify peptides inhibiting the assembly of the tetrameric enzyme. Remarkably, the GQNGISDL octapeptide, mimicking the 296–303 portion of hLDH‐A C‐terminal region, was observed to effectively inhibit the target enzyme. Moreover, by dissecting the action of this octapeptide, the cGQND cyclic tetrapeptide was found to act as the parental compound. Furthermore, we performed assays using MCF7 and BxPC3 cultured cells, exclusively expressing hLDH‐A and hLDH‐B, respectively. By means of these assays we detected a selective action of linear and cyclic GQND tetrapeptides, inhibiting lactate secretion in MCF7 cells only. Overall, our observations suggest that peptides mimicking the C‐terminal region of hLDH‐A effectively interfere with protein–protein interactions responsible for the assembly of the tetrameric enzyme. [ABSTRACT FROM AUTHOR]

Nowadays, global warming caused by the increasing levels of CO2 has become a serious environmental problem. Membrane separation technology has demonstrated its promising potential in carbon capture due to its easy operation, energy-efficientness and high efficiency. Interfacial polymerization process, as a facile and well-established technique for preparing membranes with a thin selective layer, has been widely used for fabricating commercial reverse osmosis and nanofiltration membranes in water treatment domain. To push forward such an interfacial polymerization process in the research of CO2 separation membranes, herein we make a review on the regulation and research progress of the interfacial polymerization membranes for CO2 separation. First, a comprehensive and critical review of the progress in the monomers, nanoparticles and interfacial polymerization process optimization for preparing CO2 separation membrane is presented. In addition, the potential of molecular dynamics simulation and machine learning in accelerating the screen and design of interfacial polymerization membranes for CO2 separation are outlined. Finally, the possible challenges and development prospects of CO2 separation membranes by interfacial polymerization process are proposed. It is believed that this review can offer valuable insights and guidance for the future advancement of interfacial polymerization membranes for CO2 separation, thereby fostering its development. [ABSTRACT FROM AUTHOR]

Abstract An automated pipeline for comprehensive calculation of intermolecular interaction energies based on molecular force-fields using the Tinker molecular modelling package is presented. Starting with non-optimized chemically intuitive monomer structures, the pipeline allows the approximation of global minimum energy monomers and dimers, configuration sampling for various monomer–monomer distances, estimation of coordination numbers by molecular dynamics simulations, and the evaluation of differential pair interaction energies. The latter are used to derive Flory–Huggins parameters and isotropic particle–particle repulsions for Dissipative Particle Dynamics (DPD). The computational results for force fields MM3, MMFF94, OPLS-AA and AMOEBA09 are analyzed with Density Functional Theory (DFT) calculations and DPD simulations for a mixture of the non-ionic polyoxyethylene alkyl ether surfactant C10E4 with water to demonstrate the usefulness of the approach. Scientific Contribution To our knowledge, there is currently no open computational pipeline for differential pair interaction energies at all. This work aims to contribute an (at least academically available, open) approach based on molecular force fields that provides a robust and efficient computational scheme for their automated calculation for small to medium-sized (organic) molecular dimers. The usefulness of the proposed new calculation scheme is demonstrated for the generation of mesoscopic particles with their mutual repulsive interactions.

Glycolysis of poly(ethylene terephthalate) (PET) is a prospective way for degradation of PET to its monomer bis(hydroxyethyl) terephthalate (BHET), providing the possibility for a permanent loop recycling. However, most reported glycolysis catalysts are homogeneous, making the catalyst difficult to recover and contaminating the products. Herein, we reported on the Pd-Cu/γ-Al2O3 catalyst and applied it in the glycolysis of PET as catalyst. The formed structure gave Pd-Cu/γ-Al2O3 a high active surface area, which enabled these micro-particles to work more efficiently. The PET conversion and BHET yield reached 99% and 86%, respectively, in the presence of 5 wt% of Pd-Cu/γ-Al2O3 catalyst within 80 min at 160 °C. After the reaction, the catalyst can be quickly separated by filtration, so it can be easily reused without significant loss of reactivity at least five times. Therefore, the Pd-Cu/γ-Al2O3 catalyst may contribute to an economically and environmentally improved large-scale recycling of PET fiber waste. [ABSTRACT FROM AUTHOR]

This study presents exceptional perception into the phase transition behavior of binary mixtures containing 3-chloro-2-hydroxypropyl methacrylate (3C2HM) or 2-N-morpholinoethyl methacrylate (2NMEM) in supercritical CO2 at different operating temperatures (313.2–393.2 K) and pressures (3.36–33.90 MPa). The findings are expected to significantly contribute to the evolution of advanced materials and technologies in several industrial sectors. As temperature increases at constant pressure, carbon dioxide (CO2) solubility in the monomer aqueous phase decreases. However, the solvability of the binary systems improved with temperature and mole fraction at steady pressure. The 2NMEM component exhibited higher polarizability and lower surface tension than the 3C2HM monomer, making it less soluble in CO2, which is a nonpolar compound. The solution phase of the binary systems exhibited Type I phase behavior, and the phase diagrams were nearly identical. The experimental solubility data were adequately correlated with the Peng–Robinson equation of state with the aid of molecular interaction parameters (IPs) which was evaluated at 353.2 K. The optimized molecular IPs were nearly zero, confirming that both binary systems were nearly ideal mixture systems as the temperature increased. The model precision was evaluated by calculating the percentage of root-mean-square deviation (RSD%) at five temperatures using the molecular IPs. The calculated RSD% of the CO2 + 3C2HM and CO2 + 2NMEM systems were 4.70% and 4.91%, respectively, indicating that the model values fit reasonably well. Therefore, the predicted phase behavior agrees well with the experimental phase transitions of both systems. The characteristics of the critical solution curve were simulated to realise the interactions and transition behavior of the studied binary systems. This is the first study to demonstrate the solubility of CO2 + 3C2HM and CO2 + 2NMEM chemical mixtures, and it will be significant for chemical industries. [ABSTRACT FROM AUTHOR]

The heterometallic [Ag(I)/Fe(II)] molecular electrocatalysts for hydrogen production were introduced here to recognize the mutual role of metallic nuclearity and ligand engineering. A series of ferrocenyl dithiophosphonate stabilized mononuclear [Ag(PPh3)2{S2PFc(OR)}] {where R=Me (1), Et (2), nPr (3), iPr (4), iAmyl (5); Fc=Fe (ɳ5‐C5H4) (ɳ5‐C5H5)} and dinuclear [Ag(PPh3){S2PFc(OR}]2 {where R=Et (2 a), and nPr (3 a)} complexes were synthesized and characterized by SCXRD, NMR (31P and 1H), ESI‐MS, UV‐Vis, and FT‐IR spectroscopy. The comparative electrocatalytic HER behavior of 1–5 and 2 a–3 a showed effective current density of 1 mA/cm2 with overpotentials ranging from 772 to 991 mV, demonstrating the influence of extended and branched carbon chains in dithiophosphonates and metallic (mono‐/di−) nuclearity, which correlates with documented tetra‐nuclear [Ag4(S2PFc(OnPr)4], 6. DFT study suggests the coordinated (μ1‐S) site of ligands is the reactivity center and the adsorption energy of intermediate [H*‐SM] varies with the engineering of ligand and nuclearity. A catalytic mechanism using mononuclear (1) and di‐nuclear (2 a) was proposed with the assistance of DFT. Each complex, being the first example of Ag(I) dithiophosphonates, exhibits intense photoluminescence with high quantum yields ranging from 33 % to 67 %. These results link the lower nuclearity structures to their physical and catalytic properties. [ABSTRACT FROM AUTHOR]

An automated pipeline for comprehensive calculation of intermolecular interaction energies based on molecular force-fields using the Tinker molecular modelling package is presented. Starting with non-optimized chemically intuitive monomer structures, the pipeline allows the approximation of global minimum energy monomers and dimers, configuration sampling for various monomer–monomer distances, estimation of coordination numbers by molecular dynamics simulations, and the evaluation of differential pair interaction energies. The latter are used to derive Flory–Huggins parameters and isotropic particle–particle repulsions for Dissipative Particle Dynamics (DPD). The computational results for force fields MM3, MMFF94, OPLS-AA and AMOEBA09 are analyzed with Density Functional Theory (DFT) calculations and DPD simulations for a mixture of the non-ionic polyoxyethylene alkyl ether surfactant C10E4 with water to demonstrate the usefulness of the approach. Scientific Contribution To our knowledge, there is currently no open computational pipeline for differential pair interaction energies at all. This work aims to contribute an (at least academically available, open) approach based on molecular force fields that provides a robust and efficient computational scheme for their automated calculation for small to medium-sized (organic) molecular dimers. The usefulness of the proposed new calculation scheme is demonstrated for the generation of mesoscopic particles with their mutual repulsive interactions. [ABSTRACT FROM AUTHOR]

Cellulose-based materials are not in short supply and are characterized by relatively low cost. On the other hand, cellulose fibers have a wide range of valuable physical, chemical and mechanical properties that make them indispensable in a number of sectors of the national economy. Along with valuable qualities, natural and artificial cellulose fibers also have some disadvantages that limit their use in technology and in the national economy. These are low resistance to the action of microorganisms, relatively low heat resistance, chemical resistance, flammability, etc., which reduce their service life and limit their scope. One of the ways to eliminate these shortcomings is the modification of natural and artificial macromolecular compounds by chemical and physicochemical methods. Improving the properties of cellulose and its derivatives can be achieved by various modification methods, among which one of the most promising is the radiation-chemical grafting of various monomers. One of the advantages of this method, in comparison with others, is the production of field worlds that are not contaminated with impurities, the presence of which can adversely affect their physicochemical properties. Another advantage is the relative ease of formation of macroradicals necessary to initiate the process of graft copolymerization. Quite a lot of work has been devoted to the radiation grafting of various monomers to cellulose and its derivatives; at present, some of them are beginning to be widely used in the national economy. In the light of the foregoing, the grafting of fluorine-containing monomers, the polymers and copolmers of which have such very valuable and specific properties as high heat resistance, chemical resistance, light resistance, decay resistance and hydrophobicity to cellulose and its derivatives, is of great scientific and practical interest. This work is the synthesis of graft copolymers of cotton cellulose with vinyl fluoride by the radiation-chemical method from the vapor phase, the study of the effect of radiation dose rate, reaction time, the presence and nature of solvents on the course of this process and the yield of graft copolymers, as well as the study of such important physical and chemical properties and operational properties of the original, irradiated and grafted copolymers, such as sorption capacity and density, hydrophobicity and swelling, degree of whiteness, mechanical properties, thermal stability, the nature of the change in the supramolecular structure as a result of grafting fluorine-containing polymers.

Addressing the environmental impact of poly(ethylene terephthalate) (PET) disposal highlights the need for efficient recycling methods. Chemical recycling, specifically alkaline hydrolysis, presents a promising avenue for PET waste management by depolymerizing PET into its constituent monomers. This study focuses on optimizing the pressurized alkaline hydrolysis process for post-consumer PET residues obtained from packaging materials. Post-consumer PET packaging waste was chemically recycled by means of an alkaline hydrolysis reaction in a 2 L pressurized reactor under varying conditions of the NaOH/PET ratio and temperature. The reaction's progress was monitored by sampling the liquid phase hourly over a four-hour period. The obtained products were purified, with a focus on isolating terephthalic acid (TPA). Higher temperatures (150 °C) resulted in superior TPA yields (>95%) compared to lower temperatures (120 °C). The NaOH/PET ratio showed minimal influence on the TPA yield. The optimal conditions (T = 150 °C; NaOH:PET = 2) were identified based on TPA yield and reaction cost considerations. This study demonstrates the feasibility of pressurized alkaline hydrolysis for PET recycling, with optimized conditions yielding high TPA purity and efficiency. [ABSTRACT FROM AUTHOR]

Alumina ceramic is an ideal candidate for armor protection, but it is limited by the difficult molding or machining process. Three-dimensional printing imparts a superior geometric flexibility and shows good potential in the preparation of ceramics for armor protection. In this work, alumina ceramics were manufactured via 3D printing, and the effects of different monomers on the photosensitive slurry and sintered ceramics were investigated. The photosensitive slurries using dipropylene glycol diacrylate (DPGDA) as a monomer displayed the optimal curing performance, with a low viscosity, small volume shrinkage and low critical exposure energy, and each of the above properties was conducive to a good curing performance in 3D printing, making it a suitable formula for 3D-printed ceramic materials. In the 3D-printed ceramics with DPGDA as a monomer, a dense and uniform microstructure was exhibited after sintering. In comparison, the sample with trimethylolpropane triacrylate (TMPTA) showed an anisotropic microstructure with interlayer gaps and a porosity of about 9.8%. Attributed to the dense uniform microstructure, the sample with DPGDA exhibited superior properties, including a relative density of 97.5 ± 0.5%, a Vickers hardness of 19.4 ± 0.8 GPa, a fracture toughness of 2.6 ± 0.27 MPa·m1/2, a bending strength of 690 ± 54 MPa, and a dynamic strength of 3.7 ± 0.6 GPa at a strain rate of 1200 s−1. [ABSTRACT FROM AUTHOR]

OSCA/TMEM63 is a newly identified family of mechanically activated (MA) ion channels in plants and animals, respectively, which convert physical forces into electrical signals or trigger intracellular cascades and are essential for eukaryotic physiology. OSCAs and related TMEM16s and transmembrane channel‐like (TMC) proteins form homodimers with two pores. However, the molecular architecture of the mammalian TMEM63 proteins remains unclear. Here we elucidate the structure of human TMEM63A in the presence of calcium by single particle cryo‐EM, revealing a distinct monomeric architecture containing eleven transmembrane helices. It has structural similarity to the single subunit of the Arabidopsis thaliana OSCA proteins. We locate the ion permeation pathway within the monomeric configuration and observe a nonprotein density resembling lipid. These results lay a foundation for understanding the structural organization of OSCA/TMEM63A family proteins. [ABSTRACT FROM AUTHOR]

The degree of monomer conversion (DC) values of three different dental composites were examined using three different methods: surface microhardness (ratio of bottom/top), Fourier-transform infrared (FT-IR), and differential scanning calorimetry (DSC). Two of the dental composites included in the study were nanohybrid (Dentsply Neo Spectra ST HV and Omnichroma), and one was a microhybrid-labeled newly marketed composite containing nanoparticles (Dentac Myra). Composite discs were prepared according to the methodology for all methods and analyzed (2 mm thickness × 5 mm diameter). Surface microhardness values were measured in Vickers Hardness Number (VHN), while FT-IR and DSC values were obtained in percentage (%). Significant differences were observed in both bottom/top surface microhardness values and DC values obtained from FT-IR. However, there was no statistical difference in the ratio of bottom/top microhardness values. Neo Spectra ST HV exhibited superior performance in both microhardness and monomer conversion compared to the other two composites. Newly marketed Myra showed values close to Omnichroma. It was found that the values obtained by the DSC method were parallel to those obtained by FT-IR. In conclusion, the structure of dental composites leads to different mechanical properties. Additionally, DSC measurements and FTIR spectra were found to be complementary techniques for characterizing monomer conversion values. [ABSTRACT FROM AUTHOR]

(1,4-Bis (dimethylmethoxy silane) benzene was synthesized by Grignard reaction fromp-dibromobenzene, dimeth-yldimethoxy silane and magnesium chips, and then the target product 1,4-bis (dimethylhydroxy silane) benzene was prepared by hydrolysis. The product structure was characterized by infrared spectroscopy, and the effects of stirring rate, dropping time, ratio of raw materials and solvent on the yield of phenylenedisiloxane were discussed. The effects of hydrolysis catalyst and feeding time on the yield of phenylenedisiloxane hydroxyl monomer were also studied. The results showed that phenylenedisiloxy silane and phenylenedisiloxy were successfully synthesized by Grignard reaction and hydrolysis, and the optimum conditions were as follows; stirring rate 200 r/min, dropping time 3 h, the ratio of p-dibromobenzene and dimethyldimethoxy silane to magnesium 1:2. 4:2, 1400 mL tetrahydrofuran as solvent, and the yield of phenylenedisiloxy silane monomer was 64.2%. The optimum conditions for preparing phenylenedisiloxane hydroxyl monomer by hydrolysis of phenylenedisiloxane were as follows; 2500 mL H3P04 (5 wt%) phosphoric acid as hydrolysis catalyst, feed for 3.5 h, thus the yield of phenylenedisiloxane hydroxyl monomer was 77%. [ABSTRACT FROM AUTHOR]

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Throughout its lifecycle, Entamoeba histolytica encounters a variety of stressful conditions. This parasite possesses Heat Shock Response Elements (HSEs) which are crucial for regulating the expression of various genes, aiding in its adaptation and survival. These HSEs are regulated by Heat Shock Transcription Factors (EhHSTFs). Our research has identified seven such factors in the parasite, designated as EhHSTF1 through to EhHSTF7. Significantly, under heat shock conditions and in the presence of the antiamoebic compound emetine, EhHSTF5, EhHSTF6, and EhHSTF7 show overexpression, highlighting their essential role in gene response to these stressors. Currently, only EhHSTF7 has been confirmed to recognize the HSE as a promoter of the EhPgp5 gene (HSE_EhPgp5), leaving the binding potential of the other EhHSTFs to HSEs yet to be explored. Consequently, our study aimed to examine, both in vitro and in silico, the oligomerization, and binding capabilities of the recombinant EhHSTF5 protein (rEhHSTF5) to HSE_EhPgp5. The in vitro results indicate that the oligomerization of rEhHSTF5 is concentration-dependent, with its dimeric conformation showing a higher affinity for HSE_EhPgp5 than its monomeric state. In silico analysis suggests that the alpha 3 α-helix (α3-helix) of the DNA-binding domain (DBD5) of EhHSTF5 is crucial in binding to the major groove of HSE, primarily through hydrogen bonding and salt-bridge interactions. In summary, our results highlight the importance of oligomerization in enhancing the affinity of rEhHSTF5 for HSE_EhPgp5 and demonstrate its ability to specifically recognize structural motifs within HSE_EhPgp5. These insights significantly contribute to our understanding of one of the potential molecular mechanisms employed by this parasite to efficiently respond to various stressors, thereby enabling successful adaptation and survival within its host environment. [ABSTRACT FROM AUTHOR]

The current dental resin composites often suffer from polymerization shrinkage, which can lead to microleakage and potentially result in recurring tooth decay. This study presents the synthesis of a novel monomer, (3,9-diethyl-1,5,7,11-tetraoxaspiro[5,5]undecane-3,9-diyl)bis(methylene) bis((2-(3-(prop-1-en-2-yl)phenyl)propan-2-yl)carbamate) (DDTU-IDI), and evaluates its effect in the formulation of low-shrinkage dental resin composites. DDTU-IDI was synthesized through a two-step reaction route, with the initial synthesis of the required raw material monomer 3,9-diethyl-3,9-dihydroxymethyl-1,5,7,11-tetraoxaspiro-[5,5] undecane (DDTU). The structures were confirmed using Fourier-transform infrared (FT-IR) spectroscopy and hydrogen nuclear magnetic resonance (1HNMR) spectroscopy. Subsequently, DDTU-IDI was incorporated into Bis-GMA-based composites at varying weight percentages (5, 10, 15, and 20 wt%). The polymerization reaction, degree of conversion, polymerization shrinkage, mechanical properties, physicochemical properties and biocompatibility of the low-shrinkage composites were thoroughly evaluated. Furthermore, the mechanical properties were assessed after a thermal cycling test with 10,000 cycles to determine the stability. The addition of DDTU-IDI at 10, 15, and 20 wt% significantly reduced the polymerization volumetric shrinkage of the experimental resin composites, without compromising the degree of conversion, mechanical and physicochemical properties. Remarkably, at a monomer content of 20 wt%, the polymerization shrinkage was reduced to 1.83 ± 0.53%. Composites containing 10, 15, and 20 wt% DDTU-IDI exhibited lower water sorption and higher contact angle. Following thermal cycling, the composites exhibited no significant decrease in mechanical properties, except for the flexural properties. Significance. DDTU-IDI has favorable potential as a component which could produce volume expansion and increase rigidity in the development of low-shrinkage dental resin composites. The development of low-shrinkage composites containing DDTU-IDI appears to be a promising strategy for reducing polymerization shrinkage, thereby potentially enhancing the longevity of dental restorations. • A new monomer "DDTU-IDI" was synthesized through a simple two-step reaction route. • The composites containing 10 wt% ∼ 20 wt% DDTU-IDI exhibited low polymerization shrinkage. • The addition of DDTU-IDI effectively maintained the mechanical properties of the composites. • The composites containing DDTU-IDI showed favorable resistance to aging. • The novel composites may be a promising dental restoration material in reducing the occurrence of secondary caries. [ABSTRACT FROM AUTHOR]

Cellulose-based materials are not in short supply and are characterized by relatively low cost. On the other hand, cellulose fibers have a wide range of valuable physical, chemical and mechanical properties that make them indispensable in a number of sectors of the national economy. Along with valuable qualities, natural and artificial cellulose fibers also have some disadvantages that limit their use in technology and in the national economy. These are low resistance to the action of microorganisms, relatively low heat resistance, chemical resistance, flammability, etc., which reduce their service life and limit their scope. One of the ways to eliminate these shortcomings is the modification of natural and artificial macromolecular compounds by chemical and physicochemical methods. Improving the properties of cellulose and its derivatives can be achieved by various modification methods, among which one of the most promising is the radiationchemical grafting of various monomers. One of the advantages of this method, in comparison with others, is the production of field worlds that are not contaminated with impurities, the presence of which can adversely affect their physicochemical properties. Another advantage is the relative ease of formation of macroradicals necessary to initiate the process of graft copolymerization. Quite a lot of work has been devoted to the radiation grafting of various monomers to cellulose and its derivatives; at present, some of them are beginning to be widely used in the national economy. In the light of the foregoing, the grafting of fluorine-containing monomers, the polymers and copolmers of which have such very valuable and specific properties as high heat resistance, chemical resistance, light resistance, decay resistance and hydrophobicity to cellulose and its derivatives, is of great scientific and practical interest. This work is the synthesis of graft copolymers of cotton cellulose with vinyl fluoride by the radiation-chemical method from the vapor phase, the study of the effect of radiation dose rate, reaction time, the presence and nature of solvents on the course of this process and the yield of graft copolymers, as well as the study of such important physical and chemical properties and operational properties of the original, irradiated and grafted copolymers, such as sorption capacity and density, hydrophobicity and swelling, degree of whiteness, mechanical properties, thermal stability, the nature of the change in the supramolecular structure as a result of grafting fluorine-containing polymers. [ABSTRACT FROM AUTHOR]

The use of collagen is the recent development in various medical fields. Huge quantities of hide and skin trimmings are generated during the leather processing are wasted or underutilized. Trimmings contain collagen which can be beneficially extracted and utilized for high value products. Poly methyl methacrylate based denture materials exhibit serious concerns such as high porosity, presence of residual monomer, shrinkage, distortion and high rate of deterioration of the materials. This study aims to incorporate extracted Type I collagen with polymer to obtain denture base and investigate its chemical and mechanical properties. The present research methodology also reduces the quantity of monomer and acrylic resin usage. The collagen was extracted from animal skin and hide trimmings which are otherwise disposed as wastes. This study investigated the effect of visco-elastic characteristics of resulted specimens and their transition temperature, mechanical properties, decomposition temperature and leachability. The collagen-based specimens have better tensile strength with high decomposition temperature compared to control specimens. Scanning Electron Microscopy analysis revealed that the experimental specimens was cohesive and homogeneous which explained the higher tensile and decomposition values. The study suggests that collagen cross-linked acrylic denture base exhibit better mechanical and thermal resistance properties when compared to control specimens. The study indicates that biomaterials are emerging as smart products of value in human health. [ABSTRACT FROM AUTHOR]

Three liquid crystalline monomers were systematically designed, synthesised and characterised. Methyl methacrylic unit was linked to the mesogenic compound, 4′-Undecycloxybiphenyl-4-yl 4-octyloxy-2-(pent-4-en-1-yloxy) benzoate, (Me), using disiloxane, ester and siloxane units respectively. In the first compound, 4′-(undecyloxy)-[1,1′-biphenyl]-4-yl 2-((5-(3-(4-(methacryloyloxy)butyl)-1,1,3,3-tetramethyldisiloxanyl)pentyl)oxy)-4-(octyloxy)benzoate, (M1), the methyl methacrylic unit was linked to the mesogen by disiloxane group, (Si–O–Si), while ester group, (COOC), was used in the second compound, 4′-(undecyloxy)-[1,1′-biphenyl]-4-yl 2-((5-(methacryloyloxy)pentyl)oxy)-4-(octyloxy)benzoate, (M2), and siloxane unit, (Si–O), in the third compound, 4′-(undecyloxy)-[1,1′-biphenyl]-4-yl 2-((5-((4-(methacryloyloxy)butyl)dimethylsilyl)pentyl)oxy)-4-(octyloxy)benzoate, (M3). The introduction of the methyl methacrylic unit caused the melting point of the compounds to reduce with Me melting at 53.3 °C, M1 at −8.1 °C and M2 at −12.5 °C. The three compounds showed characteristic nematic textures when observed under POM and when compared to the mesogenic compound (Me, 71.7 °C), there were remarkable reduction in the clearing points of the compounds, with M1 clearing at 18.6 °C, M2 at 68.8 °C and M3 at 10.3 °C. Finally, there was appreciable increment in the nematic phase range for the compounds when compared to the mesogen, Me, 18.4 °C. The range was 26.7 °C for M1, 81.3 °C for M2 and since there was no observable crystallization point for M3, the range was not determined. [ABSTRACT FROM AUTHOR]

Context: The present work encompasses the theoretical investigation of 14 benzimidazole-based (seven vinyl fused monomeric benzimidazole (VFMBI) and seven vinyl fused oligomeric benzimidazole (VFOBI)) derivatives using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) techniques. The effects of electron donor and acceptor groups on the electronic structure such as HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) energies, HOMO-LUMO energy gap, ionization potentials (IPs), electron affinities (EAs), internal reorganization energies of holes and electrons (λh/e), and excited state properties have been explored in the present work. In addition, natural bond orbital (NBO) analysis of these compounds has been investigated to reveal the typical stabilization interactions in these molecules. Hence, the aim of the present work is to explore the electronic structures and optoelectronic properties of the title molecules on the basis of the DFT quantum chemical calculations and to make an idea on the parameters influencing the optoelectronic efficiency toward a better understanding of the structure-property relationships. Moreover, the calculated results reveal the suitable optoelectronic properties of benzimidazole oligomer derivatives using theoretical techniques. Of the investigated molecules, 4_MABIMCY and 4_MABIOCY show potential optoelectronic properties and can be used as a potential charge transport material due to their narrow band gap, high hyperpolarizability, low ionization potential, and high electron affinity. The larger λab and λem values favor the system to be used as a potential optoelectronic material with better optical properties. Methods: All quantum chemical calculations were carried out using Gaussian09 theoretical chemistry code. Ground state calculations were made using the B3LYP/6-31+G(d,p) method. All excited state calculations had been computed using TDB3P86/6-311++(d,p). The initial structure for excited state calculations was optimized using the AM1 semi-empirical method. [ABSTRACT FROM AUTHOR]

Molecularly imprinted polymer (MIP) has gained wide interest among researchers due to its unique molecular recognition of the template that is suitable as a drug carrier. Therefore, the preparation and formulation of the MIP are significant to suit the needs of the intended use. Due to its significance in drug delivery, this review aims to highlight various methods in the preparation of MIP, the composition for both controlled and stimuli‐responsive drug delivery systems, and the release mechanism of the drugs. In drug delivery systems, MIP should have a sustained release performance as well as flexibility in surface modification for targeted delivery via a range of stimuli‐responses, including external stimuli (magnetic, light) and internal stimuli (pH, temperature, redox, biological). The properties of sustained release and targeted delivery of the MIP can improve the drug's therapeutic efficacy as well as the breakthrough for the tumor targeting application. [ABSTRACT FROM AUTHOR]

In this work 4,4-dichlorodiphenylsulfone was synthesized in the presence of the moisture-absorbing agent phosphorus pentoxide. The influence of temperature, phosphorus pentoxide concentration, and reaction time on product yield was investigated. Optimal synthesis conditions were determined: 70°C, phosphorus pentoxide concentration of 0.31 M, and a reaction time of 6 h. The structure of synthesized 4,4′-dichlorodiphenylsulfone was identified using spectroscopic methods. The proposed synthesis method can be used for small-scale production of 4,4′-dichlorodiphenylsulfone. [ABSTRACT FROM AUTHOR]

This work addresses a novel bio-solvolysis process for the treatment of complex poly(ethylene terephthalate) (PET) waste using a biobased monoethylene glycol (BioMEG) as a depolymerization agent in order to achieve a more sustainable chemical recycling process. Five difficult-to-recycle PET waste streams, including multilayer trays, coloured bottles and postconsumer textiles, were selected for the study. After characterization and conditioning of the samples, an evaluation of the proposed bio-solvolysis process was carried out by monitoring the reaction over time to determine the degree of PET conversion (91.3–97.1%) and bis(2-hydroxyethyl) terephthalate (BHET) monomer yield (71.5–76.3%). A monomer purification process, using activated carbon (AC), was also developed to remove the colour and to reduce the metal content of the solid. By applying this purification strategy, the whiteness (L*) of the BHET greatly increased from around 60 to over 95 (L* = 100 for pure white) and the Zn content was significantly reduced from around 200 to 2 mg/kg. The chemical structure of the purified monomers was analyzed via infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC), and the composition of the samples was measured by proton nuclear magnetic resonance (1H-NMR), proving a high purity of the monomers with a BHET content up to 99.5% in mol. [ABSTRACT FROM AUTHOR]

Synthesis of molecularly imprinted polymers (MIP) has gained wide interest as drug delivery vehicles in recent years. The conventional one‐variable‐at‐a‐time method for determining the best formulation ratio of MIP templates is resource‐ and time‐consuming. Thus, this study focused on the response surface methodology optimization of the best formulation for MIP preparation using methacrylic acid and divinylbenzene as functional monomer and cross‐linker, respectively. Two preparation systems were studied, namely microwave (MW)‐assisted and conventional synthesis. The MIPs showed spherical particles with smaller particle sizes (500 nm–1.45 μm) and higher yields (0.5–1.2 g) via MW‐assisted synthesis as compared to the conventional synthesis (size 660 nm–3.65 μm, yield 0.5–1.15 g). MW‐assisted synthesis is faster and more efficient to synthesize controlled shapes and sizes of MIP particles. The rebinding properties of prepared MIP via MW were higher (7.15 ± 0.02 mg/g) than conventional synthesis (3.00 ± 0.31 mg/g). The empirical models were developed to correlate the output response of rebinding properties and input variables. The analysis of variance confirmed that experimental data were superbly fitted to the proposed response models. A satisfactory correlation between the experimental and predicted values was obtained by both MIP prepared via MW‐assisted and conventional synthesis. [ABSTRACT FROM AUTHOR]

The present work is devoted to the consideration of gemini surfactant monomers with a nonionic hydrophilic part and a different structure of the spacer connecting the hydrocarbon chains. It is possible to single out two conditional conformations of monomers depending on the spacer type: with an «extended» and «compact» spacer in the case of a flexible etoxylated or hydrocarbon chain, and only with the «extended» rigid spacer in the case of aromatic ring in it. The length for all three types of spacers in the case of their «extended» conformation is approximately the same for the considered bis-surfactants and allows two hydrocarbon molecules to be vertically introduced into the resulting cavity. The «compact» conformation of flexible spacers ensures the implementation of intramolecular CH‧‧‧HC interactions between hydrocarbon chains, which are not carried out in monomers with «extended» one. The thermodynamic parameters of formation for the found monomer conformations are calculated. For gemini surfactant conformers, the formation of structures with a «compact» spacer is more advantageous according to the Gibbs energy due to the formation of intramolecular CH‧‧‧HC interactions between hydrophobic chains of the amphiphilic compound. Comparison of the contributions of intramolecular CH‧‧‧HC interactions to the formation enthalpy and entropy of bis-surfactants with an etoxylated bridge in a «compact» conformation reveals good agreement with the similar contributions of intermolecular ones for dioxyethylated alcohols. It shows the same nature of CH‧‧‧HC interactionns realizing both inside a molecule with two hydrocarbon chains and between two surfactant molecules with single hydrocarbon chain.

The review highlights the relationship between the molecular organization of the light-harvesting complex of photosystem II (LHCII) and sunlight utilization by higher plants. The molecular form of LHCII switches rapidly and reversibly during diurnal changes of light intensity, from low (ca. 10) to high [ca. 1,000 µmol(photon) m-2 s-1], so the sensitivity of LHCII to light may control the balance between light harvesting and photoprotection state. Our understanding and concept of this mechanism are based on the knowledge of the structure and photophysics of different LHCII molecular forms: monomer, dimer, trimer, and aggregate. It is proposed that LHCII monomers, dimers, and lateral aggregates are fundamental blocks of excess light-dissipation machinery. Trimer is exceptionally well suited to play a physiological role of an antenna complex. A correlation between the LHCII molecular form and the presence of xanthophyll cycle pigment violaxanthin and zeaxanthin in the complex structure is also shown. Moreover, the role of LHCII protein phosphorylation in thylakoid membrane architecture is also discussed. The dual function of LHCII has been studied in the natural thylakoid membranes of chloroplasts, in the artificial lipid-LHCII model membranes, and by suspension of LHCII in a detergent solution.

Glycolysis of poly(ethylene terephthalate) (PET) is a prospective way for degradation of PET to its monomer bis(hydroxyethyl) terephthalate (BHET), providing the possibility for a permanent loop recycling. However, most reported glycolysis catalysts are homogeneous, making the catalyst difficult to recover and contaminating the products. Herein, we reported on the Pd-Cu/γ-Al2O3 catalyst and applied it in the glycolysis of PET as catalyst. The formed structure gave Pd-Cu/γ-Al2O3 a high active surface area, which enabled these micro-particles to work more efficiently. The PET conversion and BHET yield reached 99% and 86%, respectively, in the presence of 5 wt% of Pd-Cu/γ-Al2O3 catalyst within 80 min at 160 °C. After the reaction, the catalyst can be quickly separated by filtration, so it can be easily reused without significant loss of reactivity at least five times. Therefore, the Pd-Cu/γ-Al2O3 catalyst may contribute to an economically and environmentally improved large-scale recycling of PET fiber waste.

Natural Kosa silk is one of the textile fibers to be used in apparel application. Since it is proteinous and hygroscopic fiber and gets affected easily by microbes during usage and storage. Hence, this special type of silk produced in Chhattisgarh state of India, needs to be treated for the antimicrobial treatment for its better applications in various fields. Therefore, in the present work, the Kosa silk was modified by grafting of quaternary ammonium compound-containing monomer through thermo-chemical route. Experimental conditions for achieving optimum grafting of ionic monomer [2-(methacryloyloxy)ethyl] trimethyl ammonium chloride (MAETC) was investigated. Redox combination of ceric ammonium nitrate as a redox initiator and nitric acid (HNO3) as catalyst, by successively varying reaction conditions like concentration of initiator, catalyst and desired monomers under optimized reaction conditions were performed. The grafted silk material was characterized by Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR) and X-Ray Diffraction Analysis (XRD) techniques. The antibacterial study of grafted silk material having quaternary ammonium groups is an emerging group of antibacterial agents, which can be used as disinfectants. Using agar well method demonstrated that the grafted silk (KS-g-MAETC) inhibited the growth of Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. As this grafted silk material has potent antibacterial activity, it may be used in the garment industry as well as for various biomedical applications, thus, serving the humanity. [ABSTRACT FROM AUTHOR]

Monomers, dimers, and individual FOF1-ATP synthase subunits are, presumably, involved in the formation of the mitochondrial permeability transition pore (PTP), whose molecular structure, however, is still unknown. We hypothesized that, during the Ca2+-dependent assembly of a PTP complex, the F-ATP synthase (subunits) recruits mitochondrial proteins that do not interact or weakly interact with the F-ATP synthase under normal conditions. Therefore, we examined whether the PTP opening in mitochondria before the separation of supercomplexes via BN-PAGE will increase the channel stability and channel-forming capacity of isolated F-ATP synthase dimers and monomers in planar lipid membranes. Additionally, we studied the specific activity and the protein composition of F-ATP synthase dimers and monomers from rat liver and heart mitochondria before and after PTP opening. Against our expectations, preliminary PTP opening dramatically suppressed the high-conductance channel activity of F-ATP synthase dimers and monomers and decreased their specific "in-gel" activity. The decline in the channel-forming activity correlated with the reduced levels of as few as two proteins in the bands: methylmalonate–semialdehyde dehydrogenase and prohibitin 2. These results indicate that proteins co-migrating with the F-ATP synthase may be important players in PTP formation and stabilization. [ABSTRACT FROM AUTHOR]

The degree of monomer conversion (DC) values of three different dental composites were examined using three different methods: surface microhardness (ratio of bottom/top), Fourier-transform infrared (FT-IR), and differential scanning calorimetry (DSC). Two of the dental composites included in the study were nanohybrid (Dentsply Neo Spectra ST HV and Omnichroma), and one was a microhybrid-labeled newly marketed composite containing nanoparticles (Dentac Myra). Composite discs were prepared according to the methodology for all methods and analyzed (2 mm thickness × 5 mm diameter). Surface microhardness values were measured in Vickers Hardness Number (VHN), while FT-IR and DSC values were obtained in percentage (%). Significant differences were observed in both bottom/top surface microhardness values and DC values obtained from FT-IR. However, there was no statistical difference in the ratio of bottom/top microhardness values. Neo Spectra ST HV exhibited superior performance in both microhardness and monomer conversion compared to the other two composites. Newly marketed Myra showed values close to Omnichroma. It was found that the values obtained by the DSC method were parallel to those obtained by FT-IR. In conclusion, the structure of dental composites leads to different mechanical properties. Additionally, DSC measurements and FTIR spectra were found to be complementary techniques for characterizing monomer conversion values.

An attempt has been made to graft copolymerize the vinyl monomer methacrylonitrile onto poly tetrafluoroethylene-co-ethylene, known as Tefzel film, by the double-irradiation method in aqueous medium. Optimum conditions for attaining the maximum percentage of grafting were evaluated. The maximum percentage of grafting for methacrylonitrile was obtained 128.7 % at an optimum dose of 24.9 kGy using 2.98 mol L-1 of methacrylonitrile. Investigations on the effects of different chain-length aliphatic alcohols, methanol, ethanol, n-butanol, cyclohexanol and amyl alcohol on the grafting percentages of methacrylonitrile have been performed. Characterization of Tefzel and grafted Tefzel films have been performed by infrared spectroscopy and Thermogravimetric Analysis. Methacrylonitrile grafted Tefzel films showed better thermal stability. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Semantic dementia (SD) is a progressive neurodegenerative disease associated with impaired vocabulary that progresses to memory impairment. Post‐mortem immunohistochemical analysis is the current reliable method of differentiating TDP‐43 deposits in cortical tissue; no means of antemortem diagnosis exists in biofluids, let alone in plasma. METHODS: Here the multimer detection system (MDS) was used to quantify the oligomeric TDP‐43 (o‐TDP‐43) concentrations in plasma of Korean SD patients (n = 16, 6 male, 10 female, ages 59–87). The o‐TDP‐43 concentrations were compared with the total TDP‐43 (t‐TDP‐43) concentrations quantified through conventional enzyme‐linked immunosorbent assay (ELISA). RESULTS AND DISCUSSION: Only MDS showed a significant increase in o‐TDP‐43 concentrations in the plasma of patients with SD compared to other neurodegenerative disorders and normal controls (p < 0.05). Based on these results, o‐TDP‐43 concentrations through the application of MDS may be a useful plasma biomarker in SD‐FTD (frontotemporal dementia) diagnosis. [ABSTRACT FROM AUTHOR]

The major monomer and oligomer of proanthocyanidins from the petals, seeds, fruits or pericarps of 11 plants were detected, and the difference of proanthocyanidin contents were analyzed in a variety of plants in this study. The catechin(C), epicatechin(EC), gallic acid(GA), procyanidin B2 (PCB2), procyanidin B4(PCB4), procyanidin A2(PCA2) of the 11 plants were extracted by 85% ethanol solution under ultrasonic, purified by Oasis PRiME HLB solid phase extraction column and separated by high performance liquid chromatography(HPLC). The result showed that monomers or oligomers of proanthocyanidins could be detected in 11 plants under the selected chromatographic conditions, and the content was mainly proanthocyanidin oligomers(OPC). Among them, the content of proanthocyanidins in grape seeds was the highest and the types were the most. Six proanthocyanidin monomers and oligomers were all detected in grape seeds. Two monomers, C and GA, and three oligomers, PCB2, PCB4 and PCA2, were detected in rose petals and peanut seed coats, respectively. In blueberry, walnut kernel, lycium ruthenicum murray and purple cabbage, except one proanthocyanidin monomer was detected, three kinds of proanthocyanidin oligomers were detected in blueberry and walnut kernel, while only PCB2 and PCB4 were detected in lycium ruthenicum murray and purple cabbage. The pericarp of red potato and purple potato only had OPCs; and the types of proanthocyanidin monomers and oligomers in red pepper and pericarps of dragon fruit were few and the content was low. In addition, the seed and pericarp of grape, peanut kernel and its seed coat were different parts of the same plant, and the types and content of proanthocyanidins were different. The types and contents of proanthocyanidins in different plants were different. The types and contents of proanthocyanidins in different parts of the same plant were also different. The differences of distribution, composition and concentration of proanthocyanidins in different plants lay a foundation for the study of structure-activity relationship and its development and utilization. [ABSTRACT FROM AUTHOR]

Owing to the strict hard/soft dichotomy between the lanthanoids and tellurium atoms, and the strong affinity of lanthanoid ions for high coordination numbers, low‐coordinate, monomeric lanthanoid tellurolate complexes have remained elusive as compared to the lanthanoid complexes with lighter group 16 elements (O, S, and Se). This makes the development of suitable ligand systems for low‐coordinate, monomeric lanthanoid tellurolate complexes an appealing endeavor. In a first report, a series of low‐coordinate, monomeric lanthanoid (Yb, Eu) tellurolate complexes were synthesized by utilizing hybrid organotellurolate ligands containing N‐donor pendant arms. The reaction of bis[2‐((dimethylamino)methyl)phenyl] ditelluride, 1 and 8,8′diquinolinyl ditelluride, 2 with Ln0 metals (Ln=Eu, Yb) resulted in the formation of monomeric complexes [LnII(TeR)2(Solv)2] [R=C6H4‐2‐CH2NMe2] [3: Ln=Eu, Solv=tetrahydrofuran; 4: Ln=Eu, Solv=acetonitrile; 5: Ln=Yb, Solv=tetrahydrofuran; 6: Ln=Yb, Solv=pyridine] and [EuII(TeNC9H6)2(Solv)n] (7: Solv=tetrahydrofuran, n=3; 8: Solv=1,2‐dimethoxyethane, n=2), respectively. Complexes 3–4 and 7–8 represent the first sets of examples of monomeric europium tellurolate complexes. The molecular structures of complexes 3–8 are validated by single–crystal X‐ray diffraction studies. The electronic structures of these complexes were investigated using Density Functional Theory (DFT) calculations, which revealed appreciable covalency between the tellurolate ligands and lanthanoids. [ABSTRACT FROM AUTHOR]

Objective: This research employed a network meta-analysis (NMA) to examine the effectiveness of five traditional Chinese medicine (TCM) monomers for promoting motor function recovery in rats with blunt spinal cord injury (SCI). Methods: Wangfang, China National Knowledge Infrastructure, Web of Science, Embase, Chinese Scientific Journal Database, PubMed, and the Chinese Biomedical Literature Databases were searched for retrieving relevant articles published from their inception to December 2022. Two reviewers performed screening of search results, data extraction, and literature quality assessment independently. Results: For this meta-analysis, 59 publications were included. Based on the recovery of motor function at weeks 1, 2, 3, and 4 in NMA, almost all TCM groups had significantly increased positive effects than the negative control animals. In terms of cumulative probability, the tanshinone IIA (TIIA) group ranked first in restoring motor function in the first week after blunt SCI, and the resveratrol (RSV) group ranked first during the last 3 weeks. Conclusion: The NMA revealed that TCM monomers could effectively restore motor function in the rat model of blunt SCI. In rats with blunt SCI, TIIA may be the most effective TCM monomer during the first week, whereas RSV may be the most effective TCM monomer during the last 3 weeks in promoting motor function recovery. For better evidence reliability in preclinical investigations and safer extrapolation of those findings into clinical settings, further research standardizing the implementation and reporting of animal experiments is required. [ABSTRACT FROM AUTHOR]

Existing approaches for the 3D modeling of tunnels suffer from several problems, such as highly difficult data acquisition, redundancy of model data, large computational burden, and the inability of the resulting models to be monolithic. Therefore, solutions to the tunnel network modeling problem for complex structures need to be proposed and elaborated in detail. In this paper, a construction method for a three-dimensional tunnel general monomer model based on parallel pathfinding is proposed. Widely used tunnel CAD drawings are analyzed and read, a disordered arc ensemble intersection trend decision method is developed, and an automatic path extraction solution algorithm for unidirectional modeling of tunnel centerlines is constructed. By constructing and splicing the surface elements of the 3D model, a monomeric 3D tunnel model representing the complex network structure is finally obtained. Moreover, the modeling of shafts is realized based on the monomer model, allowing for the three-dimensional topological relationships between different sub-levels of the tunnel and the ground to be established. The automatic modeling method proposed in this paper is applied to the digital twin platform of a filling project in a mining area in Gansu province, China. The experimental results demonstrate that the 3D tunnel models constructed in this way have a smaller data volume, higher modeling accuracy, and more stable growth of modeling speed. [ABSTRACT FROM AUTHOR]

The review highlights the relationship between the molecular organization of the light-harvesting complex of photosystem II (LHCII) and sunlight utilization by higher plants. The molecular form of LHCII switches rapidly and reversibly during diurnal changes of light intensity, from low (ca. 10) to high [ca. 1,000 µmol(photon) m-2 s-1], so the sensitivity of LHCII to light may control the balance between light harvesting and photoprotection state. Our understanding and concept of this mechanism are based on the knowledge of the structure and photophysics of different LHCII molecular forms: monomer, dimer, trimer, and aggregate. It is proposed that LHCII monomers, dimers, and lateral aggregates are fundamental blocks of excess light-dissipation machinery. Trimer is exceptionally well suited to play a physiological role of an antenna complex. A correlation between the LHCII molecular form and the presence of xanthophyll cycle pigment violaxanthin and zeaxanthin in the complex structure is also shown. Moreover, the role of LHCII protein phosphorylation in thylakoid membrane architecture is also discussed. The dual function of LHCII has been studied in the natural thylakoid membranes of chloroplasts, in the artificial lipid-LHCII model membranes, and by suspension of LHCII in a detergent solution. [ABSTRACT FROM AUTHOR]

Tooth restoration involves the use of various types of materials. In modern reality, light-curing composite materials are used for this purpose. Also, polymer cements of various types of polymerization are used to fix indirect structures in highly aesthetic areas. All dental composites are polymerized according to the free radical type. The formation of free radicals and curing occur as a result of a thermal, chemical, or photochemical reaction. Polymerization of composites never occurs at 100%; upon contact with air, the surface of the material interacts with oxygen, which leads to the termination (inhibition) of the polymerization reaction. To prevent the formation of an oxy-geninhibited layer (OIL) on the surface of the composite, chemically inert, oxygen-impermeable protective glycerol gels are used. To evaluate the feasibility and effectiveness of glycerol in preventing the oxygen-inhibited layer formation and to determine the relationship between the group of the composite and its qualitative composition during the formation of an oxygen-inhibited layer during polymerization. This study was carried out using an Infralum FT-801 IR Fourier spectrometer in KBr tablets. 135 samples of 12 various composite materials were studied; each was subjected to IR spectrometry, cured in glycerol or without glycerol. 15 specimens of Enamel plus UE composite material underwent pre-polymerization heat in a special oven (Micerium; Avegno, Italy) to 55°C before one heating cycle. The obtained results allowed us to conclude that the type of composite material does not significantly affect the process of oxygen inhibited layer formation. Regardless of the composite material group, under aerobic conditions, an incomplete conversion occurs, and an oxygen inhibited layer is formed. Anaerobic conditions do the conversion completely, which leads to the absence of oil, which was confirmed by infrared spectroscopy data. [ABSTRACT FROM AUTHOR]