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Poly(hydroxy urethanes) (PHUs) have been considered attractive and safer variants of conventional polyurethanes (PUs). To improve the prerequisites of green and sustainable chemistry herein, we propose the synthesis and utilization of cyclic carbonate monomers majorly derived from vanillin, a lignin derivative, and CO2 for the development of PHUs. Kinetic evaluation on the polymerization temperature ascertained 80°C as the optimum condition for PHU synthesis. The structural evaluation of PHUs was carried out by various spectroscopic techniques, such as FTIR, 1HNMR, and 13C‐NMR, molar masses were determined by gel permeation chromatography (Mn varied between 2500 and 11,100 g/mol), and thermal properties evaluated by differential scanning calorimeter (Tg in the ranges of 28–42°C), and thermogravimetric analysis (stable above 180°C). Since the PHUs are enriched with pendant hydroxyl groups on their backbone which can promote adhesion, lap shear studies on the aluminum substrate exhibited a maximum shear strength of 1.65 ± 0.37 MPa. This study demonstrates an attractive and environment‐friendly pathway for developing novel PHUs network using renewable biobased resources and further explores its applicability as adhesives. [ABSTRACT FROM AUTHOR]

Ethyl carbamate, a potential carcinogen, is formed in wine as a result of a chemical reaction between ethanol and urea during fermentation and storage. Using genome editing methods, a modified strain of wine yeast Saccharomyces cerevisiae was constructed, with a deletion of the CAR1 arginase gene, leading to a decrease in the formation of urea from arginine. Transcriptome analysis by high-throughput sequencing identified 738 genes whose transcription level reliably changed more than twofold as a result of deletion of the CAR1 gene. Expression of most genes of the central metabolic pathways in the CAR1 deletion strain was decreased; increased transcription levels were observed for the Map kinase signaling cascades. Among the genes of arginine metabolism pathways, the level of transcription of the ornithine aminotransferase gene CAR2 increased significantly. The wine material obtained using a strain with a deletion of the CAR1 gene under micro-winemaking conditions contained 25% less urea than in the case of using an unmodified strain. The resulting strain of wine yeast, having lower urea levels, may be promising for winemaking. [ABSTRACT FROM AUTHOR]

Alcoholic beverages are multicomponent mixtures containing several carcinogenic compounds, including ethyl carbamate, which was evaluated in fruit spirits against the limit proposed by the International Alliance for Responsible Drinking (IARD) and then in terms of associated health. It was above the limit in 40% of the samples and statistically higher in stone fruit spirits. The MOE values below the limit were obtained for 49% and 98% of the samples at average and chronic heavy consumption by men, while for women the limit was reached by 19% and 96% of the samples, respectively. The lifetime cancer risk (LCR) approach based on the oral slope factor indicated risk concern for 96% of the samples at average consumption, regardless of gender, while LCR based on virtually safe dose indicated 25% and 69% of the samples posing a risk to women's and men's health, respectively. Preventive measures during spirit production and legal regulation of ethyl carbamate should be considered. [ABSTRACT FROM AUTHOR]

We studied the effects of polyphenolic composition BP-C2, comprising molybdenum with lignin derivatives, on lung carcinogenesis induced by urethane in the progeny of F0 male BALB/c mice preconceptionally exposed to radiation in a dose of 1 Gy. The multiplicity of lung tumors in the progeny of irradiated mice was higher than in the progeny of non-irradiated male parents by 50% in females and 43% in males (p<0.05). In F1 mice (progeny of irradiated F0 male parents treated with BP-C2), the multiplicity of lung tumors was also higher, but this increase was less pronounced: 35% in females (p=0.3852) and 23% in males (p=0.0766). We have demonstrated that administration of BP-C2 to irradiated parents (F0) efficiently inhibits carcinogenesis in their F1 progeny. The use of BP-C2 in irradiated male parents and their progeny not only reduced the multiplicity of tumors, but also normalized body weights in the F1 progeny. Our study demonstrates potential of the polyphenolic composition BP-C2 for chemoprophylaxis of radiation-induced transgenerational carcinogenesis. [ABSTRACT FROM AUTHOR]

The effect of gamma-radiation doses of 50, 100, and 150 kGy on the deformation and strength properties of a plasticized binder based on low-molecular-weight polydiene urethane rubbers of the PDI-3B brand has been studied. To assess changes in the strength of the plasticized binder depending on the dose of gamma irradiation, the fracture energies were calculated at temperatures of 223, 295, and 323 K. At these test temperatures, the conditional stress increased and deformation slightly decreased depending on the dose of gamma irradiation compared with those of the original sample. Sharp changes in the deformation and strength characteristics occurred at a test temperature of 223 K; the strength of the irradiated samples increased by a factor of more than 4, and the deformation decreased slightly compared to that of the original sample. This trend persisted with an increase in the test temperature, but the difference was almost halved. Such an effect of gamma irradiation on the test material can be explained by the prevalence of crosslinking over degradation. [ABSTRACT FROM AUTHOR]

This study explores the synthesis and evaluation of UV-curable urethane (meth)acrylates (UA) incorporating a Diels–Alder adduct (HODA), diisocyanate, poly(ethylene glycol), and hydroxy (meth)acrylate. Six UAs, distinguished by the soft segment of polymer chains, underwent comprehensive characterization using FTIR and NMR spectroscopy. Real-time monitoring of the UV-curing process and analysis of self-healing properties were performed. The research investigates the influence of various molecular weights of PEGs on the self-healing process, revealing dependencies on photopolymerization kinetics, microstructure, thermal properties, and thermoreversibility of urethane (meth)acrylates. This work provides valuable insights into the development of UV-curable coatings with tailored properties for potential applications in advanced materials. [ABSTRACT FROM AUTHOR]

The colloidal stability of silica O-I hybrid sols that have a high degree of condensation could result in the formation of a hard coating film on a substrate, which could depend on the properties of solvents used in the sol-gel reaction. In this study, the effect of the solvent type on the colloidal stability and degree of condensation of the silica sols was investigated by preparing various silica O-I hybrid sols using different solvent mixtures composed of various aprotic and protic solvents in the presence of amphiphilic urethane acrylate. Silica sols prepared using the appropriate aprotic-protic solvent mixture showed a higher degree of condensation and long-term colloidal stability, which was confirmed using 29Si-NMR and DLS. Furthermore, the coating film formed from these silica sols showed a remarkable hardness of 0.97 GPa, with a thickness of 4.76 µm confirmed using nanoindentation measurements. [ABSTRACT FROM AUTHOR]

Background: Based on the bioinformatics prediction, this study investigates the correlation between aberrant transcription factor Frizzled 5 (FZD5) expression and the establishment of non-small cell lung cancer (NSCLC). Methods: A mouse model with regard to primary NSCLC was encouraged by intraperitoneal injection of urethane. Lentivirus-based FZD5 silencing was then administrated to examine its role in tumorigenesis in the mouse lung. Silencing of FZD5 was induced in two NSCLC cell lines to examine its function in the malignant behavior pertaining to cells in vitro. Quantitative methylation-specific PCR was employed to assess the DNA methylation level within the NSCLC cells. DNA methyltransferases (DNMTs) that administer FZD5 were assessed by chromatin immunoprecipitation assay. Consequently, overexpression of DNMT3A was introduced in mice and NSCLC cells to verify its regulation on FZD and its biological roles in NSCLC development. Results: In NSCLC, FZD5 expression is elevated, and its knockdown reduced tumor incidence rate in the urethane-challenged mice. The FZD5 silencing also inhibited proliferation, migration, as well as invasion with regard to Calu-3 and NCI–H1299 cells in vitro. The aberrant upregulation with regard to FZD5 in NSCLC was due to at least partly by reduced promoter methylation level. DNMT3A, which bound to FZD5 promoter to suppress its transcription, was poorly expressed in NSCLC. Artificial upregulation of DNMT3A suppressed urethane-induced lung carcinogenesis in mice and suppressed the malignant phenotype pertaining to NSCLC cells in vitro. Conclusion: This research demonstrates that the lack of DNA methylation level-induced activation of FZD5 is correlated with NSCLC's onset and progression.

Abstract Background Aspects of glutamate neurotransmission implicated in normal and pathological conditions are predominantly evaluated using in vivo recording paradigms in rats anesthetized with isoflurane or urethane. Urethane and isoflurane anesthesia influence glutamate neurotransmission through different mechanisms; however, real-time outcome measures of potassium chloride (KCl)-evoked glutamate overflow and glutamate clearance kinetics have not been compared within and between regions of the brain. In order to maintain rigor and reproducibility within the literature between the two most common methods of anesthetized in vivo recording of glutamate, we compared glutamate signaling as a function of anesthesia and brain region in the rat strain most used in neuroscience. Methods In the following experiments, in vivo amperometric recordings of KCl-evoked glutamate overflow and glutamate clearance kinetics (uptake rate and T80) in the cortex, hippocampus, and thalamus were performed using glutamate-selective microelectrode arrays (MEAs) in young adult male, Sprague-Dawley rats anesthetized with either isoflurane or urethane. Results Potassium chloride (KCl)-evoked glutamate overflow was similar under urethane and isoflurane anesthesia in all brain regions studied. Analysis of glutamate clearance determined that the uptake rate was significantly faster (53.2%, p

Nowadays, global warming and fossil fuel depletion are two unsolved problems. Research is underway on renewable energies, which are new energy sources. This study aims to improve the performance of microbial fuel cells (MFCs), a renewable energy generation method. Urethane was used as the electrode material for MFC. Urethane is an excellent material suitable for use as MFC electrodes because of its durability, porosity, and other properties. However, urethane itself is not conducive. This study used conductive urethane, which is coated with activated carbon powder, as the electrode material. This material is used in deodorizing filters, air conditioning filters, and air cleaner filters. To improve the performance of MFC, carbon nanotubes and activated carbon powder were added to the urethane electrodes. PTFE was also used to improve cathodic function. PTFE is used as a binder in many microbial fuel cells. The performance of the electrodes was compared. The analysis included power density measurements and discharge characteristics. It was confirmed that the use of PTFE improves the power density by a factor of two or more. The MFC generated a maximum power density of 28.27 μW/cm2. SEM image analysis of the electrode after the experiment confirmed that PTFE could reduce the adhesion of microorganisms on the cathode surface. These results imply that the use of conductive urethanes as electrodes in MFCs is effective. The addition of carbon nanotubes, activated carbon powder, and PTFE has enabled the use of urethane as an electrode material for microbial fuel cells.

This study aims to improve the thermal and mechanical properties of epoxy-based materials. For this purpose, the structure of epoxy resins was changed by chemical modification and epoxy resin containing urethane was synthesized. The synthesized resin was blended with commercial epoxy resin at the ratios of 25%, 50%, 75% by weight and hardened by curing. The thermal and mechanical properties of urethane-containing epoxy materials prepared in different proportions were compared with those produced from commercial epoxy resin. The structural characterization of the prepared materials was investigated by Fourier Transform Infrared Spectroscopy (FTIR) analysis, their thermal behavior was investigated by Thermogravimetric Analysis (TGA), and their mechanical properties were investigated by Dynamic Mechanical Analysis (DMA). TGA and DMA analyses of the materials showed that the presence of urethane in the structure of epoxy resins significantly changed the mechanical and thermal properties. It was observed that the storage and loss modulus values of urethane-containing resins increased approximately 2.5 times compared to commercial epoxy resins, and a decrease of approximately 10% in thermal degradation temperatures was observed.

The world desperately needs new technologies and solutions for gas capture and separation. To make this possible, molecular modeling is applied here to investigate the structural, thermodynamic, and dynamical properties of a model for the poly(urethane urea) (PUU) oligomer model to selectively capture CO2 in the presence of CH4. In this work, we applied a well-known approach to derive atomic partial charges for atoms in a polymer chain based on self-consistent sampling using quantum chemistry and stochastic dynamics. The interactions of the gases with the PUU model were studied in a pure gas based system as well as in a gas mixture. A detailed structure characterization revealed high interaction of CO2 molecules with the hard segments of the PUU. Therefore, the structural and energy properties explain the reasons for the greater CO2 sorption than CH4. We find that the CO2 sorption is higher than the CH4 with a selectivity of 7.5 at 298 K for the gas mixture. We characterized the Gibbs dividing surface for each system, and the CO2 is confined for a long time at the gas–oligomer model interface. The simulated oligomer model showed performance above the 2008 Robeson's upper bound and may be a potential material for CO2/CH4 separation. Further computational and experimental studies are needed to evaluate the material. [ABSTRACT FROM AUTHOR]

We compared the effects of two anesthetics, isoflurane and urethane on bladder function in rats. Arterial pressure, cystometry (CMG), and rhythmic bladder contractions (RBCs) under isovolumetric conditions, mechanosensitive single-unit afferent activities (SAAs), bladder compliance and bladder myogenic microcontractions (bladder microcontractions), and bladder blood flow, and blood and urine biochemical tests were investigated in isoflurane- or urethane-anesthetized female rats. In results of the CMG, 3/8 rats in the isoflurane group and 7/7 rats in the urethane group showed constant bladder neurogenic contractions for micturition, whereas 5/8 rats in the isoflurane group showed unstable contractions or overflow incontinence. The RBCs appeared in the urethane group but not in the isoflurane group, and SAAs in both the Aδ- and C-fibers, bladder compliance, and bladder microcontractions in the isoflurane group were higher than those in the urethane group during bladder distension. The blood biochemical test showed that the serum calcium level was higher in the isoflurane group. The mean arterial pressure and bladder blood flow were not different between the groups. The results showed that urethane anesthesia more retains bladder neurogenic contractions for micturition compared to isoflurane. In contrast, isoflurane anesthesia more retains bladder function during the storage phase compared to urethane.

Propolis is a natural agent produced by honeybees from several botanical sources. The purpose of our study is to evaluate the antitumor effect of propolis extract (PE) against urethane-induced lung cancer compared to Cisplatin (CIS) in rats. Some biochemical parameters of oxidative stress, gene expression and histopathology and transmission electron microscopy were estimated and performed. PE improved the induced changes in glutathione, malondialdehyde and superoxide dismutase concentration generated by urethane. Moreover, PE increased the expression of EGFR-mRNA. Examination of the light and electron microscopic sections manifested that the URT group displayed the excessive abnormal distribution of collagen fibers and the growth of papillary adenocarcinoma in the terminal bronchial lumen with thickening in the bronchial wall, inflammation and alveolar collapse. PE was able to decrease the above induced changes. In conclusion, a recent study concluded that PE could be an excellent source of natural chemicals that fight lung cancer.

The kinetics of the synthesis of green polyurethane from the reaction between tannic acid (TA) and L-lysine diisocyanate (LDI) were investigated using the differential scanning calorimeter (DSC) technique and dynamic rheological tests. The evaluation of the reaction behavior of the prepared samples was carried out using nonisothermal conditions at dynamic heating rates of 5, 10, 15, and 20°C/min. The evolution of the activation energy with conversion was computed through the five isoconversional methods of Ozawa-Flynn-Wall and Kissinger-Akahira-Sunose (KAS), the Ozawa-Flynn-Wall method (OFW), Friedman (FR), Starink, and Vyazovkin. The average activation energy calculated from these methods was estimated at 46.5, 46.8, 47.2, 47.3, and 51.4 KJ/mol, respectively. The preexponential factor was evaluated at 5.04 × 10 5 1/s. The overall reaction order (n + m) was also found to be around 1.8912. The results of the combination of the model-free method and model-fitting approach exhibited that the reaction mechanism was an autocatalytic type, implying the autocatalytic effect of the urethane groups formed during the reaction. The obtained kinetic for TA/LDI was verified through its good agreement with the experimental data. Moreover, the results found from the isothermal rheological test show that with increasing temperature, the gelation time decreases. [ABSTRACT FROM AUTHOR]

A theoretical study of urethane formation through the reaction of phenyl isocyanate and butan-1-ol was carried out, without and in the presence of morpholine, and 4-methylmorpholine catalysts. The reaction with and without catalysts was studied at BHandHLYP/6-31G(d) and G3MP2BHandHLYP levels of theories. The reaction mechanism in the presence of catalysts differs significantly from the catalyst-free case and includes seven steps. The catalyst-free system was investigated along with the catalytic process, the geometries were optimized, and the corresponding thermodynamic properties were calculated. Calculated reactant complexes were compared with crystal structures of morpholine, and 4-methylmorpholine complexed with diols found in the literature. The structures were strikingly similar and thus, the validity of the proposed and studied general organocatalytic reaction mechanism was partially verified. Meanwhile, an irregularity in the energy profile occurred due to the zwitterionic nature of an intermediate. To handle the irregularity, a correction was implemented which handles the appearance of a zwitterionic structure and the corresponding energetic properties. The results showed that morpholine is less effective catalyst compared to 4-methylmorpholine, which can be associated with the difference in their PA (1523.95 and 963.07 kJ/mol, respectively). The current results prove the important role of amine catalysts in urethane synthesis which can be applied in polyurethane catalyst design and development. [ABSTRACT FROM AUTHOR]

[Display omitted] • Whole-cell sensory-evoked responses were explored in VPM thalamic neurons of rat pups. • Principal whisker stimulation evoked a group of large-amplitude EPSPs. • Large EPSPs evoked spike bursts and plateau potentials. • Large EPSPs nested gamma-barrages of IPSPs. • IPSPs prevented the inactivation of action potentials. During the critical period of postnatal development, brain maturation is extremely sensitive to external stimuli. Newborn rodents already have functional somatosensory pathways and the thalamus, but the cortex is still forming. Immature thalamic synapses may produce large postsynaptic potentials in immature neurons, while non-synaptic membrane currents remain relatively weak and slow. The thalamocortical system generates spontaneous and evoked early gamma and spindle-burst oscillations in newborn rodents. How relatively strong synapses and weak intrinsic currents interact with each other and how they contribute to early thalamic activities remains largely unknown. Here, we performed local field potential (LFP), juxtacellular, and patch-clamp recordings in the somatosensory thalamus of urethane-anesthetized rat pups at postnatal days 6–7 with one whisker stimulation. We removed the overlying cortex and hippocampus to reach the thalamus with electrodes. Deflection of only one (the principal) whisker induced spikes in a particular thalamic cell. Whisker deflection evoked a group of large-amplitude excitatory events, likely originating from lemniscal synapses and multiple inhibitory postsynaptic events in thalamocortical cells. Large-amplitude excitatory events produced a group of spike bursts and could evoke a depolarization block. Juxtacellular recordings confirmed the partial inactivation of spikes. Inhibitory events prevented inactivation of action potentials and gamma-modulated neuronal firing. We conclude that the interplay of strong excitatory and inhibitory synapses and relatively weak intrinsic currents produces sensory-evoked early gamma oscillations in thalamocortical cells. We also propose that sensory-evoked large-amplitude excitatory events contribute to evoked spindle-bursts. [ABSTRACT FROM AUTHOR]

Huisgen‐click curing systems are widely used in solid propellant binders due to their low humidity sensitivity and mild reaction conditions. However, the rigid triazole rings from the Huisgen‐click reaction decrease the molecular moving ability and increase decomposition temperature, lowering the mechanical and combustion performance. Thus, we bonded the Huisgen‐click system and polyester binders with urethane, forming microphase separation and improving chemical stability. The results show that the elongation at break, tensile strength, and Young's modulus of the binders increase by 533.3%, 201.2%, and 1263.9%, respectively. Furthermore, the urethane reduces the thermal resistance index of the binders from 191.2 to 179.2°C, which means better combustion performance. Further mechanism study reveals that the urethane leads to microphase separation, which aggregates the hard segments and weakens their restriction effect on the molecular motion of polyether. Such a microphase separation brings comprehensive improvement in the mechanical properties of the solid propellants and probably can be used in other multi‐component systems of energetic materials. [ABSTRACT FROM AUTHOR]

The depletion of fossil resources as well as environmental concerns contribute to an increasing focus on finding more sustainable approaches for the synthesis of polymeric materials. In this work, a synthesis route towards non-isocyanate polyurethanes (NIPUs) using renewable starting materials is presented. Based on the terpenes limonene and carvone as renewable resources, five-membered cyclic carbonates are synthesized and ring-opened with allylamine, using thiourea compounds as benign and efficient organocatalysts. Thus, five renewable AA monomers are obtained, bearing one or two urethane units. Taking advantage of the terminal double bonds of these AA monomers, step-growth thiol-ene polymerization is performed using different dithiols, to yield NIPUs with molecular weights of above 10 kDa under mild conditions. Variation of the dithiol and amine leads to polymers with different properties, with Mn of up to 31 kDa and Tg's ranging from 1 to 29 °C. Polyurethanes find versatile applications in our daily lives, e.g., as coatings, foams and adhesives, but non-hazardous synthesis routes with renewable feedstocks are urgently needed. Here, the authors report an organocatalytic synthesis route towards non-isocyanate polyurethanes using terpenes as renewable starting materials. [ABSTRACT FROM AUTHOR]

Design and synthesis of the new polymeric adsorbents for selective and efficient removal of Hg2+ from water is an attractive target. Cross-linked poly (vinyl benzyl chloride) (PVBC) resin was prepared starting from vinyl benzyl chloride (90% mol) and ethylene glycol dimethacrylate (EGDMA) (10% mol) using suspension polymerization. Spherical PVBC beads (200–400 µm) were reacted with an excess of ethylenediamine and ethanolamine to give the corresponding pendant amine functions. Then, the aminated beads were reacted with butyl isocyanate to obtain the urea and urethane functional sorbents. These resins have good sorption capacities for mercury ions. Under non-buffered conditions, the highest mercury sorption capacities were found as 1.94 mmol Hg (II)/ g resin and 2.50 mmol Hg (II)/g resin for U-resin and PS-UR resin, respectively. pH-depending sorption experiments, kinetic measurements and adsorption isotherm models were investigated. The mercury-loaded resins can be regenerated and recycled by simple acid washings, without losing their activity. Consequently, the resins described are cost-effective adsorbents for the removal of mercury from waste water. [ABSTRACT FROM AUTHOR]

In this study, five different UV-curable polyurethane acrylate (PUA) resins (B, H:20, H:40, P:10/H:20, and P:20/H:40) were synthesized using different amounts of polyols [(2,2-bis(4-β-hydroxyethoxy) phenyl 6F propane (HEPFA); polydimethylsiloxane (PDMS); propylene glycol) which reacted with isophorone diisocyanate (IPDI) and end-capped with 2-hydroxyethyl methacrylate (HEMA). Then, a series of UV-curable PUA formulations and their nano-hybrids (B/S10-30, H20/S10-S30, H40/S10-S30, P10:H20/S10-S30, P20:H40/S10-S30) were prepared by the sol–gel method using different amounts of sol–gel solutions. The obtained formulations were cured with UV rays. The effects of PDMS, HEPFA and sol–gel content on the physical, thermal and mechanical properties of the UV-curable PUA coatings were investigated. When the HEPFA, PDMS and sol–gel content were increased in the urethane base formulation (B), the gloss increased from 98° to 117°, 133° and 137° for B, H40, P20:H40 and P20:H40/S30, respectively. TGA analysis showed that the decomposition temperatures shifted significantly upward with increasing amounts of HEPFA, PDMS and the sol–gel precursor. The water absorption of the hybrids decreased from 4.7 wt% (B) to 2.5 wt% (P20:H40/S30). The nano-hybrid coatings exhibited higher contact angle values for deionized water/ethylene glycol compared to the pure PUAs, ranging from 52°/48° (B) to 78°/76° (P20:H40/S30). The SEM analysis showed that the nano-silica particles were scattered in the polymer matrix without serious agglomeration when 30 wt% of sol–gel solution was added to B, H40 and P20:H40. These results indicate that the overall properties of the PUAs and their hybrids were improved and that they could potentially be used as coatings in practical applications. [ABSTRACT FROM AUTHOR]

The time available for proper casting of the polyurethane (PU) system after isocyanate addition (called pot life) affects the macrodiol microstructure. In this research, the effect of molecular weight (Ṁn) of hydroxyl terminated polybutadiene (HTPB) as an important macrodiol on the pot life of polyurethane system was rheologically investigated. The chemorheological behavior of polyurethane systems based on five different HTPBs with Ṁn ranging from 2810 to 4450 g/mol and two common diisocyantes (TDI and IPDI) were studied in situ. The results showed that by increasing Mn, the rotational viscosity as well as the constant reaction rate of urethane formation increases; whereas the pot life of the polyurethane system decreases. The psuedoplastic behavior of the samples showed the minimum rate constant/longest pot life at a critical molecular weight (Mc) of about 3100 g/mol, which may be due to physical chain entanglements. Rheomechanical spectrometry interestingly depicted that tan Δ originated-gel point occurs before the intersection of stored modulus (G') and loss modulus (G") (tgel< tG'=G"). The kinetic model developed by Hsich showed excellent agreement with the cross-linking data of three polyurethane systems. [ABSTRACT FROM AUTHOR]

Ethyl carbamate, the ethyl ester of carbamic acid, has been identified in fermented foods and alcoholic beverages. Since ethyl carbamate is a probable human carcinogen, reduction of its content is important for food safety and human health. In alcoholic beverages, ethyl carbamate is mostly formed from the reaction of ethanol with urea, citrulline and carbamyl phosphate during fermentation and storage. These precursors are generated from arginine metabolism by wine yeasts and lactic acid bacteria. This review summarizes the mechanisms of ethyl carbamate formation, its impact on human health and methods used in winemaking to minimize its content. These approaches include genetic modification of Saccharomyces cerevisiae wine strains targeting pathways of arginine transport and metabolism, the use of lactic acid bacteria to consume arginine, direct degradation of ethyl carbamate by enzymes and microorganisms, and different technological methods of grape cultivation, alcoholic fermentation, wine aging, temperature and duration of storage and transportation. [ABSTRACT FROM AUTHOR]

We synthesized regular polyurethanes from the diol having oxazolidone structure (Diol‐1) and the aliphatic diisocyanate by typical polyaddition. The results of the structural analysis suggested that the polyurethane having a cyclic urethane structure such as oxazolidone formed a rod‐like structure, although the control polyurethane having a chain urethane structure formed a linear structure. The polyaddition of Diol‐1 and aliphatic diisocyanate with triol having oxazolidone structure (Triol‐1) as a crosslinker also proceeded successfully to achieve corresponding polyurethanes. However, the polyurethanes containing a molar ratio of Triol‐1 less than or equal 50% were soluble in high polar organic solvents nevertheless those polyurethanes contained some trifunctional units in the polymer chain. On the other hand, the polyurethanes containing a molar ratio of Triol‐1 more than 50% were insoluble in any organic solvents. We hypothesized that the soluble polyurethanes containing Triol‐1 formed multi‐branched structure and the insoluble polyurethanes formed cross‐linking structure. Such structures of polymer chain affected significantly to the thermal properties of the obtained polyurethanes. [ABSTRACT FROM AUTHOR]

Background: Aspects of glutamate neurotransmission implicated in normal and pathological conditions are predominantly evaluated using in vivo recording paradigms in rats anesthetized with isoflurane or urethane. Urethane and isoflurane anesthesia influence glutamate neurotransmission through different mechanisms; however, real-time outcome measures of potassium chloride (KCl)-evoked glutamate overflow and glutamate clearance kinetics have not been compared within and between regions of the brain. In order to maintain rigor and reproducibility within the literature between the two most common methods of anesthetized in vivo recording of glutamate, we compared glutamate signaling as a function of anesthesia and brain region in the rat strain most used in neuroscience. Methods: In the following experiments, in vivo amperometric recordings of KCl-evoked glutamate overflow and glutamate clearance kinetics (uptake rate and T80) in the cortex, hippocampus, and thalamus were performed using glutamate-selective microelectrode arrays (MEAs) in young adult male, Sprague-Dawley rats anesthetized with either isoflurane or urethane. Results: Potassium chloride (KCl)-evoked glutamate overflow was similar under urethane and isoflurane anesthesia in all brain regions studied. Analysis of glutamate clearance determined that the uptake rate was significantly faster (53.2%, p < 0.05) within the thalamus under urethane compared to isoflurane, but no differences were measured in the cortex or hippocampus. Under urethane, glutamate clearance parameters were region-dependent, with significantly faster glutamate clearance in the thalamus compared to the cortex but not the hippocampus (p < 0.05). No region-dependent differences were measured for glutamate overflow using isoflurane. Conclusions: These data support that amperometric recordings of KCl-evoked glutamate under isoflurane and urethane anesthesia result in similar and comparable data. However, certain parameters of glutamate clearance can vary based on choice of anesthesia and brain region. In these circumstances, special considerations are needed when comparing previous literature and planning future experiments. Highlights: Potassium-evoked glutamate overflow was similar under urethane and isoflurane anesthesia. Glutamate clearance parameters were similar under both anesthesias in the cortex and hippocampus but not the thalamus. Glutamate clearance kinetics differ between brain regions when anesthetized with urethane. Experimental design, brain region of interest, and outcome parameters of glutamate clearance should be considered when designing anesthetized amperometry recordings of glutamate. [ABSTRACT FROM AUTHOR]

Food processing is an integral part of the modern food industry aimed at improving the quality, taste, and preservation of food products. In recent years, researchers have made significant progress in understanding and minimizing the harmful compounds produced during food processing, which has driven the development of effective strategies to detect, reduce, or eliminate these compounds in foods [[1]]. Control of Harmful Products in Food Processing The control of harmful products in food processing is a critical aspect of ensuring food safety and quality. [Extracted from the article]

The kinetics of the urethane forming reactions of hexamethylene diisocyanate (HDI), 4,4′-dicyclohexyl-methane-diisocyanate (HMDI) and isophorone diisocyanate (IPDI) with butan-1-ol were systematically studied by electrospray ionization mass spectrometry (ESI-MS) in the off-line mode. The reactions were performed in toluene solution in the temperature range of 50–80 °C and perdeuterated butan-1-ol was used for quenching the reaction. The butan-1-ol was employed in high excess to diisocyanates to obtain pseudo first-order rate coefficients. For rendering the kinetics, a simple A → B → C consecutive model was applied and found to adequately describe the observed kinetic behaviors. The corresponding rate coefficients were determined and reactivities of the diisocyanates were found to decrease in the order HDI > IPDI > HMDI. Furthermore, it was observed that the second isocyanate group in HDI, due to the ring formation by intramolecular hydrogen bonds, reacted faster with butan-1-ol after the first isocyanate moiety had reacted. The formation of hydrogen bonding rings was also confirmed by DFT calculations. However, the reactivity of the second isocyanate moiety (after the first one has reacted) did not change significantly in the case of HMDI. From the temperature dependences the apparent activation parameters such as the pre-exponential factors and activation energies were determined. In addition, the reactions were also studied at 80 °C in the presence of tin(II)-2-ethylhexanoate at different concentrations and a mechanism was proposed for the catalytic process. [ABSTRACT FROM AUTHOR]

Devising energy‐efficient strategies for the depolymerization of plastics and the recovery of their structural components in high yield and purity is key to a circular plastics economy. Here, we report a case study in which we demonstrate that vinylogous urethane (VU) vitrimers synthesized from bis‐polyethylene glycol acetoacetates (aPEG) and tris(2‐aminoethyl)amine can be degraded by water at moderate temperature with almost quantitative recovery (≈98 %) of aPEG. The rate of depolymerization can be controlled by the temperature, amount of water, molecular weight of aPEG, and composition of the starting material. These last two parameters also allow one to tailor the mechanical properties of the final materials, and this was used to access soft, tough, and brittle vitrimers, respectively. The straightforward preparation and depolymerization of the aPEG‐based VU vitrimers are interesting elements for the design of polymer materials with enhanced closed‐loop recycling characteristics. [ABSTRACT FROM AUTHOR]

It is highly desirable yet significantly challenging to fabricate injectable, self‐crosslinked, self‐fused, and antifouling polyzwitterionic hydrogels, whose successful preparation will expand their application scope in biomedical fields. Herein, for the first time, a novel zwitterionic monomer, carboxybetaine urethane acrylate (CBUTA) is designed and synthesized with a urethane group and zwitterion on the same side chain. The strong inter‐urethane H‐bonds and zwitterionic dipole–dipole interactions of side chains contribute to self‐crosslinked wholly supramolecular polyzwitterionic hydrogel that is directly formed from photoinitiated polymerization of CBUTA aqueous solution without adding any chemical crosslinkers. After being swollen in water, the polyCBUTA (PCBUTA) hydrogel is squeezed into small particles and freeze‐dried to obtain hydrogel powder. The injectable and wholly zwitterionic supramolecular PCBUTA hydrogel can be easily reconstructed by mixing hydrogel powder with water due to the recombination of H‐bonds of urethane groups and zwitterionic dipole–dipole interactions. The re‐formed PCBUTA hydrogel exhibits an excellent self‐fused and antifouling ability, and this injectable PCBUTA hydrogel, endowed with a microenvironment‐regulated function, demonstrates excellent glucose consumption, antioxidation, antibacterial, and angiogenesis ability, thus accelerating the infected diabetic wound healing. Overall, this work provides a promising strategy to develop injectable and wholly zwitterionic hydrogels that will find broad biomedical applications. [ABSTRACT FROM AUTHOR]

The hydrophilic extractives isolated from black alder (Alnus glutinosa) bark through hot water extraction were characterized as novel renewable macromonomers capable of forming polyurethane (PU) networks based on a commercial polyisocyanate, with partial or complete replacement of petroleum-derived polyol polyether. The bark-sourced bio-polyol mainly consists of the xyloside form of the diarylheptanoid oregonin, along with oligomeric flavonoids and carbohydrates, resulting in a total OH group content of 15.1 mmol·g−1 and a molecular weight (Mn) of approximately 750 g∙mol−1. The 31P NMR data confirmed a similar proportion of aliphatic OH and phenolic groups. Three-component PU compositions were prepared using polyethylene glycol (Mn = 400 g∙mol−1), bio-polyol (up to 50%), and polymeric diphenylmethane diisocyanate, which were pre-polymerized in tetrahydrofuran (THF) solution with tin organic and tertiary amine catalysts. The resulting mixture was cast and subjected to thermal post-curing. Calculation and experimental data confirmed the crosslinking activity of the bark-sourced bio-polyol in PU, leading to an increase in glass transition temperature (Tg), a decrease in sol fraction yield upon leaching of cured PU networks in THF, a significant increase in Young's modulus and tensile strength. The macromonomers derived from bark promoted char formation under high temperature and oxidative stress conditions, limiting heat release during macromolecular network degradation compared to bio-polyol-free PU. It was observed that amine catalysts, which are active in urethane formation with phenolic groups, promoted the formation of PU with higher Tg and modulus at tensile but with less limitation of heat liberation during PU macromolecular structure degradation. The high functionality of the bark-derived bio-polyol, along with the equal proportion of phenolic and aliphatic OH groups, allows for further optimization of PU characteristics using three variables: increasing the substitution extent of commercial polyethers, decreasing the NCO/OH ratio, and selecting the type of catalyst used. [ABSTRACT FROM AUTHOR]

Thermosetting polymers tend to have a stiffness–toughness trade-off due to the opposing relationship of stiffness and toughness on crosslink density. We hypothesize that engineering the polymer network, e.g., by incorporating urethane oligomers, we can improve the toughness by introducing variations in crosslink density. In this work, we show that a brittle methacrylated Bis-GMA resin (known as DA2) is toughened by adding a commercial urethane acrylate resin (known as Tenacious) in different proportions. The formulations are 3D printed using a vat photopolymerization technique, and their mechanical, thermal, and fracture properties are investigated. Our results show that a significant amount of Tenacious 60% w/w is required to produce parts with improved toughness. However, mechanical properties drop when the Tenacious amount is higher than 60% w/w. Overall, our results show that optimizing the amount of urethane acrylate can improve toughness without significantly sacrificing mechanical properties. In fact, the results show that synergistic effects in modulus and strength exist at specific blend concentrations. [ABSTRACT FROM AUTHOR]

SP 13 sp C NMR (CDCl SB 3 sb ): (ppm) 12.0 (SCH SB 3 sb ), 21.1 (CH SB 3 sb ), 48.0 (C-8b), 58.4 (CH SB 2 sb ), 82.0 (C-8a), 117.8 (=CH, C-6), 121.7 (=CH, C-7), 124.8 (quaternary C, C-5a), 130.4 (C ipso Me, C-8), 152.6 (>C = N-O-), 155.4 (-S-C = N-). SP 13 sp C NMR (CDCl SB 3 sb ): (ppm) 11.7 (SCH SB 3 sb ), 47.1 (C-8b), 58.0 (CH SB 2 sb ), 77.7 (C-8a), 117.0 (=CH), 120.3 (=CH), 126.5 (=CH), 126.8 (quaternary C, C-5a), 151.8 (>C = N-O-), 155.0 (-S-C = N-). SP 1 sp H NMR (CDCl SB 3 sb ): (ppm) 2.40 (s, 3 H, SCH SB 3 sb ), 4.38 (d, I J i = 14.94 Hz, 1 H, H-8b), 4.51 (m, 2 H, CH SB 2 sb ), 5.66 (d, I J i = 14.9 and 4.9 Hz, 1 H, H-8a), 5.81 (m, 2 H, H-vinylic). SP 13 sp C NMR (CDCl SB 3 sb ): (ppm) 14.7 (SCH SB 3 sb ), 35.1 (CH SB 2 sb -Ph), 46.3 (CH SB 2 sb -N<), 106.7 (=CH-NO SB 2 sb ), 115.9 (d, SP 2 sp I J i SB CF sb = 21.4 Hz, m-CH- Ar), 130.6 (d, SP 3 sp I J i SB CF sb = 8.2 Hz, o-CH- Ar), 133.4 (d, SP 4 sp I J i SB CF sb = 3.3 Hz, C- Ar), 162.3 (d, SP 1 sp I J i SB CF sb = 244.8 Hz, C-F), 165.1 (-NH-C=). [Extracted from the article]

Alternative techniques have been investigated for effectiveness in caries removal because conventional metallic dental burs can lead to an excessive loss of sound tissue. The aim of the present study is to realize a preliminary approach in obtaining effective polymer mixtures for polymeric bur development, capable of removing primary dental caries using combinations of polymers to ensure the requirements for such instruments, but also a greater compatibility with the teeth structure. This study assessed the main mechanical properties, water sorption, solubility and microscopic structure of four new polymer mixture recipes to provide essential features in obtaining experimental self-limited dental burs. Two mixtures have in their composition polymer mixtures of Bis-phenol A diglycidyl ether dimethacrylate/Triethylene glycol dimethacrylate/Urethane dimethacrylates (R1, R2), and two other mixtures have Bis-phenol A diglycidyl ether dimethacrylate/Polymethyl methacrylate/Methyl methacrylates (R3, R4). The incorporation of nanoparticles into the polymer matrix has become essential due to the need of polymer biocompatibility increasing along with teeth surface remineralization, so that the powder charge was added to four recipes, such as 5% glass with BaF2 and 0.5% graphene with silver particles. All data sets were analyzed using the One-Way ANOVA test. R3, R4 showed higher compressive strength and diametrical compression values; these values increased when glass and graphene were added. Moreover, the addition of glass particles lead to an increase in flexural strength. Regarding the sorption, sample R3 had the most significant differences between day 69 and the rest of the investigation days, while the solubility varied at different intervals. From the mechanical evaluation, we could conclude that the Bis-GMA/PMMA/MMA mixtures fit the mechanical characteristics supported by polymer burs, following future studies regarding their use on the affected dentin. [ABSTRACT FROM AUTHOR]

This review provides a comprehensive analysis of the production, classification, and quality control of cachaça, a traditional Brazilian sugarcane spirit with significant cultural importance. It explores the fermentation and distillation of sugarcane juice, the ageing process in wooden containers, and the regulatory aspects of cachaça labelling. It emphasises the role of quality control in maintaining the spirit's integrity, focusing on monitoring copper levels in distillation stills. Ethyl carbamate (EC), a potential carcinogen found in cachaça, is investigated, with the study illuminating factors influencing its formation and prevalence and the importance of its vigilant monitoring for ensuring safety and quality. It also underscores the control of multiple parameters in producing high-quality cachaça, including raw material selection, yeast strains, acidity, and contaminants. Further, the impact of ageing, wood cask type, and yeast strains on cachaça quality is examined, along with potential uses of vinasse, a cachaça by-product, in yeast cell biomass production and fertigation. A deeper understanding of the (bio)chemical and microbiological reactions involved in cachaça production is essential to facilitate quality control and standardisation of sensory descriptors, promoting global acceptance of cachaça. Continued research will address safety concerns, improve quality, and support the long-term sustainability and success of the cachaça industry. [ABSTRACT FROM AUTHOR]

SP 13 sp C NMR (CDCl SB 3 sb ): (ppm) 12.0 (SCH SB 3 sb ), 21.1 (CH SB 3 sb ), 48.0 (C-8b), 58.4 (CH SB 2 sb ), 82.0 (C-8a), 117.8 (=CH, C-6), 121.7 (=CH, C-7), 124.8 (quaternary C, C-5a), 130.4 (C ipso Me, C-8), 152.6 (>C = N-O-), 155.4 (-S-C = N-). SP 13 sp C NMR (CDCl SB 3 sb ): (ppm) 11.7 (SCH SB 3 sb ), 47.1 (C-8b), 58.0 (CH SB 2 sb ), 77.7 (C-8a), 117.0 (=CH), 120.3 (=CH), 126.5 (=CH), 126.8 (quaternary C, C-5a), 151.8 (>C = N-O-), 155.0 (-S-C = N-). SP 1 sp H NMR (CDCl SB 3 sb ): (ppm) 2.40 (s, 3 H, SCH SB 3 sb ), 4.38 (d, I J i = 14.94 Hz, 1 H, H-8b), 4.51 (m, 2 H, CH SB 2 sb ), 5.66 (d, I J i = 14.9 and 4.9 Hz, 1 H, H-8a), 5.81 (m, 2 H, H-vinylic). SP 13 sp C NMR (CDCl SB 3 sb ): (ppm) 14.7 (SCH SB 3 sb ), 35.1 (CH SB 2 sb -Ph), 46.3 (CH SB 2 sb -N<), 106.7 (=CH-NO SB 2 sb ), 115.9 (d, SP 2 sp I J i SB CF sb = 21.4 Hz, m-CH- Ar), 130.6 (d, SP 3 sp I J i SB CF sb = 8.2 Hz, o-CH- Ar), 133.4 (d, SP 4 sp I J i SB CF sb = 3.3 Hz, C- Ar), 162.3 (d, SP 1 sp I J i SB CF sb = 244.8 Hz, C-F), 165.1 (-NH-C=). [Extracted from the article]

Novel polyurethanes with exactly controlled structures, that is, alternating block polyurethanes based on poly(propylene glycol) and poly(ethylene glycol) that are linked through urethane segments, were synthesized by polyaddition polymerization. A reaction between isocyanate groups from the poly(propylene glycol) tolylene 2,4-diisocyanate terminated component and the hydroxyl groups of the poly(ethylene glycol) component as a chain extender produced the controlled structure. The chemical structure was characterized by nuclear magnetic resonance spectra, Fourier transform infrared spectroscopy, and varying poly(ethylene glycol) molecular weights. The thermal property was investigated by differential scanning calorimetry and thermogravimetric analysis. The wettability was studied using the static contact angle of water. These polymers exhibit remarkable crystallization features and very good dispersion in water. The presence of urethane segments on the molecular chains provides good stability for the dispersion in water. The obtained polymers possess good thermal properties. Differential scanning calorimetry and polarized optical microscopy revealed improved dispersion in water and increased crystallization capability in correlation with the increase of the PEG molecular weight. These polyurethanes would be promising candidates for friendly environmental polymer materials. [ABSTRACT FROM AUTHOR]

Self-matting acrylate has attracted much interest due to excellent weather resistance, hardness, water resistance, and chemical resistance. However, the poor mechanical properties of acrylate limit its application in coatings. To overcome this problem, a series of self-matting acrylate emulsions (SMAE) modified by xylitol-based hyperbranched urethane acrylate (HP-IH) were successfully synthesized. The results revealed that the amount of emulsifier was the primary factor affecting the gloss of the films. Upon the incorporation of HP-IH, the elongation at break and fracture energy of the SMAE films were significantly improved by 52.6% and 59.6%, respectively, due to the internal plastic effect and increased crosslink density induced by HP-IH. The S-2-1.5 sample exhibited the excellent comprehensive performance, i.e., tensile strength of 12.7 MPa, elongation at break of 952%, fracture energy of 71.1 MJ/m3, adhesion of 5B, temperature of 5% weight loss at 350 °C, and gloss at 60° of 14.8, respectively, indicating its great application potential in the field of low-gloss coatings. [ABSTRACT FROM AUTHOR]

Ethyl carbamate is a group of 2A carcinogen ubiquitously existed in fermented foods. The monitoring of its residues was important for evaluating the potential risk to human beings. Immunoassays with good accuracy and simplicity are great analytical tools for small molecule contaminants. However, it is typically confined in a competitive mode for small molecules with drawback of the sensitivity curbing. In this work, three different phages displayed peptides with capability of identifying the xanthyl ethyl carbamate immunocomplex were isolated from phage library. The binding mechanism of peptides and immunocomplex was studied by computer-assisted simulation. Results indicated that the xanthydrol group of xanthyl ethyl carbamate and the Asn-32 and Asn-92 residues of the antibody light chain were mainly responsible for binding. Simultaneously, a sensitive non-competitive immunoassay for detecting ethyl carbamate in wine samples was developed. The established method exhibited a limit of detection of 5.4 ng/mL and a linear range from 8.7 ng/mL to 32 ng/mL for wine samples. In comparison with the conventional competitive immunoassay, the sensitivity of the proposed non-competitive immunoassay was improved by 17-fold. The results of the immunoassay were validated by a standard ultra-performance liquid chromatography-quadrupole/orbitrap high-resolution mass spectrometry, which illustrated good reliability of the proposed assay.

This article, published in the Chemistry of Natural Compounds journal, discusses the flavonoids found in the aerial part of the Phlomis thapsoides plant, which grows in Uzbekistan. The roots, herb, and leaves of this plant are used in folk medicine for various ailments. Previous studies have focused on other chemical compounds found in this plant, but this study aimed to identify and study the flavonoids. Eight flavonoids were isolated and identified, including chrysin and rutin, which are commonly found in plants of the Phlomis genus. The article also mentions that the aerial part of P. thapsoides has sedative properties, comparable to rutin and luteolin, and suggests further investigation into its pharmacological properties. [Extracted from the article]

The article discusses the use of urethane as an anaesthetic model for natural sleep. The authors argue against a recent study that claims urethane anaesthesia is not an accurate model of natural sleep. They highlight the similarities between urethane anaesthesia and natural sleep, such as spontaneous changes in forebrain state and corresponding changes in peripheral physiological signals. The authors acknowledge that urethane anaesthesia is not identical to sleep but argue that it is the best-documented anaesthetic model for understanding sleep-like changes in the forebrain state. They call for further critical studies to examine the similarities and differences between urethane and sleep. [Extracted from the article]

The development of new photoreactive resins to obtain smart coatings and enhance the self‐healing (SH) properties of photoreactive resins has attracted great interest in the past few years, and the investigation of the relationship between phase structure and smart properties is necessary. Herein, four types of urethane acrylate resins with built‐in DA structures with different hard segment structures, and a slight change in the length of the polyol soft segment were prepared. The hard segments were made of hexamethylene diisocyanate (HDI) with a linear structure and isophorone diisocyanate (IPDI) with an alicyclic structure, and the soft segments consisted of polyethylene glycols (PEG 400 and PEG 1000, respectively). The obtained resins were used to prepare polymer films that were cured using UV radiation. The coatings obtained in this way were tested for the influence of the polymer chain architecture on the kinetics of photopolymerization, the properties of the cured coatings, as well as the thermal characteristics and thermoreversibility performance of the cured coatings and their SH ability. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Introducing covalently crosslinked network to telechelic polymers can enable the formation of advanced polymeric materials with enhanced material properties. In this contribution, well‐defined telechelic polymers bearing acetoacetate groups were synthesized via Ru‐catalyzed ring‐opening metathesis polymerization of cyclooctene in the presence of chain transfer agents. Given the unique feature of muti‐site reactive acetoacetate end groups, several crosslinked networks were constructed using different crosslinkers under mild conditions. In the Michael addition reaction system, the introduction of di/trifunctional aliphatic acrylate as crosslinkers significantly enhanced the mechanical properties of the generated crosslinked network (tensile strength up to 27 MPa, elongation at break up to 500%). On the other hand, vitrimers with dynamic covalent crosslinked networks were accessed via transamination of vinylogous urethane reaction using telechelic polymers and tris(2‐aminoethyl)amine. These vitrimers presented great mechanical properties and reprocessing properties. These strategies can be potentially applied to construct other types of high‐performance polymeric materials. [ABSTRACT FROM AUTHOR]

Calcium phosphate cements present increased biocompatibility due to their chemical composition being similar to that of the hydroxyapatite in the hard tissues of the living body. It has certain limitations due to its poor mechanical properties, such as low tensile strength and increased brittleness. Thus, the optimal way to improve properties is through the design of novel composite cements. The purpose was fulfilled using a 25% hydroxyethyl methacrylate (HEMA) mixed with 3% urethane dimethacrzlate (UDMA) base matrix with various ratios of polyethylene glycol (PEG 400) and polycaprolactone (PCL). Mineral filler is based on tricalcium phosphate (TCP) with different chitosan ratio used as bio-response enhancer additive. Four mixtures were prepared: S0—unfilled polymer matrix; S1 with 50% TCP filler; S2 with 50% chitosan + TCP filler; and S3 with 17.5% chitosan + TCP mixed with 17.5% nano hydroxyapatite (HA). The mechanical properties testing revealed that the best compressive strength was obtained by S2, followed by S3, and the worst value was obtained for the unfilled matrix. The same tendency was observed for tensile and flexural strength. These results show that the novel filler system increases the mechanical resistance of the TCP composite cements. Liquid exposure investigation reveals a relative constant solubility of the used filler systems during 21 days of exposure: the most soluble fillers being S3 and S2 revealing that the additivated TCP is more soluble than without additives ones. Thus, the filler embedding mode into the polymer matrix plays a key role in the liquid absorption. It was observed that additive filler enhances the hydrophobicity of UDMA monomer, with the matrix resulting in the lowest liquid absorption values, while the non-additivated samples are more absorbent due to the prevalence of hydrolytic aliphatic groups within PEG 400. The higher liquid absorption was obtained on the first day of immersion, and it progressively decreased with exposure time due to the relative swelling of the surface microstructural features. The obtained results are confirmed by the microstructural changes monitored by SEM microscopy. S3 and S2 present a very uniform and compact filler distribution, while S1 presents local clustering of the TCP powder at the contact with the polymer matrix. The liquid exposure revealed significant pore formation in S0 and S1 samples, while S3 and S2 proved to be more resistant against superficial erosion, proving the best resistance against liquid penetration. [ABSTRACT FROM AUTHOR]

We studied changes in the expression of early genes in hippocampal cells in response to stimulation of the dorsal medial septal area (dMSA), leading to long-term potentiation in the hippocampus. Rats under urethane anesthesia were implanted with stimulating electrodes in the ventral hippocampal commissure and dMSA and a recording electrode in the CA1 area of the hippocampus. We found that high-frequency stimulation (HFS) of the dMSA led to the induction of long-term potentiation in the synapses formed by the ventral hippocampal commissure on the hippocampal CA1 neurons. One hour after dMSA HFS, we collected the dorsal and ventral hippocampi on both the ipsilateral (damaged by the implanted electrode) and contralateral (intact) sides and analyzed the expression of genes by qPCR. The dMSA HFS led to an increase in the expression of bdnf and cyr61 in the ipsilateral hippocampi and egr1 in the ventral contralateral hippocampus. Thus, dMSA HFS under the conditions of degeneration of the cholinergic neurons in the medial septal area prevented the described increase in gene expression. The changes in cyr61 expression appeared to be dependent on the muscarinic M1 receptors. Our data suggest that the induction of long-term potentiation by dMSA activation enhances the expression of select early genes in the hippocampus. [ABSTRACT FROM AUTHOR]

An innovative promising Gallic acid anchored poly vinyl alcohol via ethyl carbamate linker (PVA-EC-GA), was functionalized to extract boron from a tourmaline ore sample from Sikait area in South Eastern Desert of Egypt, which assaying 10.45% boron oxide. Specifications for PVA-EC-GA composite were accomplished by employing a variety of methods including XPS, FT-IR, EDX, BET, 1 H-NMR, TGA, 13C-NMR and GC-MS analyses, which assure an equitable prepare of PVA-EC-GA. Investigational measurements, namely: pH, agitation time, initial concentration of boron, composite dose, co-ions, temp. and agents of eluting, have been improved. At 25°C, pH 10, 20 min agitation and 0.0092 mol/L boron ions, PVA-EC-GA composite has an extreme uptake capacity of 43.75 mg per gram which is equivalent to 175 mg/L boron ions. From the isotherm modeling, Langmuir’s quite fitting the practical data. Conferring to kinetic modeling, pseudo-second order kinetic model well predicted the kinetics of boron ions adsorption by PVA-EC-GA giving a theoretical retention capacity of 43.86 mg/g. Thermodynamic prospects expose that the adsorption process was expected as an exothermic, spontaneous, and preferable adsorption at low temp. Boron ions can be eluted from the loaded composite, by 0.5 M H2SO4 with a 97% effectiveness. [ABSTRACT FROM AUTHOR]

Ethyl carbamate (EC) is carcinogenic, and, in China, oral intake of EC mainly occurs as a result of the consumption of alcoholic beverages. To obtain the latest EC intake and risk analysis results for the general population in China, the China National Center for Food Safety Risk Assessment (CFSA) conducted the sixth total diet study (TDS) as a platform to analyze EC contents and exposure due to the intake of alcoholic beverages. A total of 100 sites in 24 provinces were involved in the collection and preparation of alcohol mixture samples for the sixth TDS. There were 261 different types of alcohol collected across the country, based on local dietary menus and consumption survey results. Ultimately, each province prepared a mixed sample by mixing their respective samples according to the percentage of local consumption. The EC levels of these twenty-four mixed samples were determined using our well-validated gas chromatography-mass spectrometry (GC-MS) method. The values ranged from 1.0 μg/kg to 33.8 μg/kg, with 10.1 μg/kg being the mean. China's EC daily intake ranged from 0.001 ng/kg bw/d to 24.56 ng/kg bw/d, with a mean of 3.23 ng/kg bw/d. According to the margin of exposure (MOE), virtually safe dose (VSD), and T25 risk assessments of the carcinogenicity of EC, the mean lifetime cancer risk for the Chinese population was 9.8 × 104, 1.5 × 10−7, and 8.6 × 10−8, respectively. These data show that the carcinogenicity of EC in the general Chinese population due to alcoholic intake is essentially minimal. [ABSTRACT FROM AUTHOR]

The amidoalkylation of a phosphonous acid containing a structural isostere of diethyl glutamiate, using ethyl carbamate and 3-(methylthio)propionaldehyde, was proposed for the synthesis of NC(O)OEt-protected phosphinic pseudo-Met-Glu-peptide. Subsequent adamantyl protection of the phosphorylic function and hydrolysis of carboxylic groups made it possible to obtain phosphinic Met-[P]-Glu peptide in the form of cyclic glutamate anhydride. It was found that the latter reacts with the third amino acid component histidine to form the phosphinic Met-[P]-Glu-γ-His tripeptide. [ABSTRACT FROM AUTHOR]

Compliance mismatch between the artificial blood vessel and the host vessel leads to abnormal hemodynamics and is a major mechanical trigger of intimal hyperplasia. Efforts have been made to achieve higher compliance of artificial blood vessels. However, the preparation of artificial blood vessels with compliance matching to host vessels has not been realized. A bi-layered artificial blood vessel was successfully prepared by dip-coating and electrospinning composite method using poly(L-Lactide-co-caprolactone) (PLCL) and thermoplastic poly(ether urethane) (TPU). In the case of a certain wall thickness (200 μm), thickness ratios of the PLCL inner layer (dip-coating method) and TPU outer layer (electrospinning method) were controlled at 0:1, 1:9, 3:7, 5:5, 7:3, and 1:0 respectively and the compliance, radial tensile properties, burst pressure, and suture retention strength were investigated. Results showed compliance value of the artificial blood vessel decreased with the increase of the thickness ratio, which suggested the compliance of the bi-layered artificial blood vessel can be regulated by adjusting the ratio of the inner and outer layer thicknesses. In the six different artificial blood vessels, the one with thickness ratio of 1:9 not only had high compliance (8.768 ± 0.393%/100 mmHg) but also can guarantee the other mechanical properties, such as the radial breaking strength (6.333 ± 0.689 N/mm), burst pressure (534.473 ± 20.899 mmHg), and suture retention strength (300.773 ± 9.351 cN). The proposed artificial blood vessel preparation method is expected to achieve compliance matching with the host vessel. It is beneficial for eliminating abnormal hemodynamics and reducing intimal hyperplasia. [ABSTRACT FROM AUTHOR]

Hiire is a pasteurization process in the production of Japanese rice wine (sake), which stabilizes the quality of product; however, it also generates the carcinogen ethyl carbamate (EC). In this study, we investigated the application of ultra-high-pressure homogenization (UHPH) as an alternative sterilization method for sake production. Microbiological analysis revealed that multiple UHPH treatments sterilized hiochi lactobacilli (Lactobacillus fructivorans , L. homohiochii , L. casei , and L. hilgardii) and Saccharomyces cerevisiae. Enzyme activity assays revealed that α-amylase, glucoamylase, and acid-carboxypeptidase activities were reduced to less than 1% of the levels in non-pasteurized sake after four-time UHPH treatment. These results show that UHPH treatment meets the two requirements of the sake sterilization process sterilization and enzyme inactivation. The UHPH-processed sake did not show any significant changes in general properties but had reduced organic acid and aromatic component contents, with ethyl caproate content showing the most significant reduction of approximately 20%. Interestingly, EC was detected in pasteurized sake but not in UHPH-processed sake. These findings indicate that the UHPH technology could be used to inactivate microorganisms and enzymes in sake without generating EC. [ABSTRACT FROM AUTHOR]