Main Reaction Research Articles

Investigation on the association between Osteopontin and Apolipoprotein E gene polymorphisms and vancomycin-induced acute kidney injury: A pharmacokinetic/pharmacogenetic study in critically ill patients.

Investigation on the association between Osteopontin and Apolipoprotein E gene polymorphisms and vancomycin-induced acute kidney injury: A pharmacokinetic/pharmacogenetic study in critically ill patients.

Salinity Tolerance in Wheat: Mechanisms and Breeding Approaches

High salinity and other abiotic stressors severely limit the productivity of wheat (Triticum aestivum L.). Wheat is a moderately salt-tolerant crop, and its salinity tolerance has been extensively studied due to the fact that it is one of the most essential food crops. It is essential to comprehend the mechanisms underlying salinity tolerance and create adaptable wheat types. In this paper, the morphological adaptations in wheat were first introduced under salinity stress, then the main physiological, biochemical and molecular reactions of wheat to salinity stress were summarized in detail. In addition, the advances in breeding approaches to salinity tolerance in wheat through germplasm evaluation, screening and gene editing were generally reviewed. Finally, proposals for further research or possible challenges in this process were also discussed. Our review will provide references for improving salt tolerance of wheat and for breeding salt-tolerant varieties.

Modeling the decarburization of expansion droplets based on the solid phase ratio of slag and data fitting during BOF steelmaking process

In the process of basic oxygen furnace steelmaking, the high-velocity jet impacts the molten metal pool, resulting in the generation of splashing metal droplets with varying particle sizes. The expansion decarburization of metal droplets in the emulsion phase is one of the main steel-slag reaction behaviors. In this paper, firstly, a theoretical decarburization model of expansion droplet was established, finding biases in their calculation results. Then, the solid phase ratio in different FeO content of slag was analyzed, demonstrating its significant impact on the reactivity performance of slag. Finally, an improved decarburization comprehensive model for expanded droplets, based on the solid phase ratio of slag and data fitting, was developed and validated using experimental data. The results indicate that the improved droplet decarburisation comprehensive model shows a good agreement with the experimental data in predicting changes in carbon content, with Pearson correlation coefficient exceeding 0.94 for different FeO contents. ‌For FeO contents of 3%, 10%, 20%, and 30%, the model achieves MAE (0.035%, 0.024%, 0.056%, 0.059%) and RMSE (0.0034%, 0.0019%, 0.011%, 0.018%), respectively. This model can accurately calculate the change of carbon content of metal droplets under various complex multiphase slag conditions.

TEXNOGEN CHIQINDILARNI GIDROMETALLURGIYA USULIDA QAYTA ISHLASH TEXNOLOGIYASI

Nowadays, the full and rational use of mineral raw materials is one of the important tasks of every mining industry. Therefore, it is important to create technologies for extracting the necessary raw materials not only from ores, but also from secondary raw materials (waste, rocks). The article presents the procedure, regulations and results of experiments on obtaining additional copper by burning and selective smelting of copper ores, as well as the main tables, graphs and chemical reactions.

Deactivation and regeneration of bimetallic Pd-Ag/Al2O3 catalyst in acetylene semi-hydrogenation process: an experimental and kinetic study

The deactivation and regeneration of a Pd-Ag/Al2O3 catalyst (2 mm in diameter, containing 0.03 wt.% Pd and 0.18 wt.% Ag) with egg-shell Pd distribution was investigated for selective hydrogenation of acetylene to ethylene (i.e., semi-hydrogenation). A high-pressure fixed-bed reactor containing a feed mixture of H2:C2H2 of 1.5 (mol./mol.) was used for catalyst performance evaluation. A regeneration protocol similar to that of the commercial plant was implemented to investigate the regeneration process. Power-law kinetics were used for the main reaction, catalyst decay, and catalyst regeneration, and the kinetic parameters were obtained by fitting with the respective experimental data. The results showed that the egg-shell width increases with time-on-stream. The performance of the catalyst was largely restored following regeneration via oxidative coke removal. Orders of 0.4 and 1 with respect to oxygen partial pressure and coke amount, respectively, were obtained for the coke burning rate.

Cyanamide-Based Cyclization Reactions for Nitrogen-Containing Heterocycles Synthesis.

Nitrogen-containing heterocycles, such as indoles and quinolines, serve as the key scaffolds in numerous pharmaceuticals, pesticides, and natural products. The synthesis methods of nitrogen-containing heterocycles show significant scientific and industrial value. As a chemical intermediate featuring dual functional groups, cyanamide plays a crucial role in organic synthesis, directly affecting the development of new drugs and the design of new materials. Particularly in the synthesis of nitrogen-containing heterocyclic compounds, the cyano group can introduce vari-ous groups through radical pathways to synthesize polycyclic N-heterocyclic frameworks, as well as yielding a variety of nitrogen-containing heterocycles through non-radical pathways. This di-verse reaction pathway makes the application of cyanamide in chemical synthesis more extensive and flexible. The progress involving cyanamide in the synthesis of quinazoline and quinazoli-none, γ-lactams, and other nitrogen-containing heterocyclic frameworks is summarized. The main mechanisms and reaction strategies are emphasized and explicated from the perspective of radical and non-radical synthetic pathways, revealing the potential application value of these compounds in different fields. This review paves the way for the synthesis of various nitrogen-containing het-erocyclic compounds, particularly in achieving green chemistry and sustainable development goals. These new methods and ideas are expected to promote the development of more efficient and economical synthesis strategies in the future, thereby advancing the widespread application of nitrogen-containing heterocyclic compounds in pharmaceuticals, agricultural chemicals, and new materials.

Clinical application of a novel hysteroscopic LNG-IUS non-suture fixation at the uterine fundus.

This study aimed to explore the feasibility and clinical effects of a novel hysteroscopic levonorgestrel-releasing intrauterine system (LNG-IUS) non-suture fixation at the uterine fundus. From October 2023 to July 2024, a prospective study involving a novel hysteroscopic LNG-IUS non-suture fixation at the uterine fundus was conducted at Obstetrics and Gynecology Hospital, Fudan University. The patient's clinical symptoms, surgical time, surgical complications, postoperative LNG-IUS expulsion, and other follow-up information were recorded. A total of 31 patients were included in this study. The average uterine depth is 9.17 ± 0.67 cm. Among them, 10 cases had a history of LNG-IUS expulsion. The average surgical time is 13.0 ± 4.1 min, and the average intraoperative blood loss is 5.3 ± 3.6 mL. All patients did not experience complications such as uterine perforation, massive bleeding, fluid overload, or postoperative infection. The average follow-up time after surgery was 6.0 ± 1.8 months, and no LNG-IUS expulsion occurred. The pain assessment and mean menstrual flow postoperation were less than preoperation, and the endometrial thickness and mean uterine volume postoperation were lower than preoperation, with statistically significant differences. For patients with dysmenorrhea, the postoperative relief rate was 96.3% (26/27), and for those with excessive menstruation, the postoperative effective rate reached 96.2% (25/26). The main adverse reaction was irregular vaginal bleeding, with an incidence rate of 61.3% (19/31). Hysteroscopic LNG-IUS non-suture fixation at the uterine fundus is a safe and effective technique, particularly suitable for patients with dysmenorrhea, excessive menstruation, or a large uterine cavity who have previously experienced LNG-IUS expulsion. This procedure is simple and minimally invasive, has a short surgical time, has minimal bleeding, and provides rapid recovery; therefore, it is worthy of clinical application.

CO2 Geothermal Power Generation: Laboratory Experiment on the Interaction Between Carbonated Water and Rishiri Island Basalt in the Vicinity of Injection Wells

Novel geothermal power generation systems are being developed that use supercritical CO2 as the heat transfer medium. In this technology, some CO2 injected into the underground reacts with surrounding water and rocks to form secondary minerals, such as carbonate minerals and clay minerals; however, the reaction mechanism in the vicinity of the injection well, the subject of this study, has not been clarified. As the first laboratory test, Rishiri Island basalt was reacted with distilled water at 250 °C for 15 days at four different CO2 concentrations to investigate the difference in reaction depending on the CO2 concentration. Na, K and Ca increased rapidly until 5 days of the reaction, with higher values at higher CO2 concentrations; Mg showed characteristic behavior with higher values in the test without CO2 (using Ar gas). The saturation index of each secondary mineral was calculated, and it was found that carbonate minerals were unsaturated and clay minerals, such as smectite, were supersaturated under all test conditions, which was in agreement with the experimental results. It is concluded that a small amount of clay minerals was formed in this test due to the low pH of the reaction solution caused by the high CO2 concentration, indicating that dissolution was the main reaction for the rocks in the vicinity of the injection well.

Catalytic Gasification of Petroleum Coke with K₂CO₃: Impact of Catalyst-Carbon Contact and the Role of the Boudouard Reaction at 950°C

The research analyzes the petroleum coke (petcoke) gasification catalysis process that includes potassium carbonate (K₂CO₃) as a catalyst while examining both catalyst interaction effects with carbon and the effect of the Boudouard reaction at high temperatures. The isothermal gasification examination under a CO₂ atmosphere at 950 °C was conducted using Thermogravimetric analysis (TGA) combined with derivative thermogravimetry (DTG). The gasification of pure petroleum coke (0% K₂CO₃) demonstrated very low reactivity given its inherent low gasification rate when unaccompanied by a catalyst but petcoke mixed with either 10% or 60% K₂CO₃ exhibited rapid mass loss rates which were demonstrated through distinct DTG peaks and notable mass diminution during the isothermal condition. The Boudouard reaction (C + CO₂ → 2CO) served as the main chemical reaction mechanism at this temperature level because of thermodynamic favorability responsible for these patterns. A custom-built TGA setup started by purging the system with argon at 700 °C for 30 minutes then ran CO₂ flow for 2.5 hours to start the gasification process.The research shows catalyst dispersion plays a major role together with catalyst contact time for boosting efficiency when both experiments used 60% K₂CO₃ but the 10% loading showed slower reaction rates. The research results demonstrate that K₂CO₃ catalytic gasification operations show promise in effective petcoke conversion under CO₂ environments at elevated temperatures.

A review on the effect of organic admixtures containing different functional groups on the hydration behaviors of Portland cement

Abstract In order to adapt to the complex service environment, the rational application of organic admixtures has become one of the important means of preparing high-performance cementitious materials. The type and functional groups of organic admixtures are crucial to the hydration degree and strength development of Portland cement. Here, the main chemical reactions occurring in different hydration stages and corresponding hydration mechanism of Portland cement were explicated in detail. On this basis, the influence feature and mechanism of organic admixtures containing different functional groups on the overall process and different stages of cement hydration were systematically reviewed. The statistical results show that organic admixtures mainly affect the induction and acceleration periods of cement hydration, and the hydration effect is closely related to the molecular weight, molecular structure, functional groups and charges of organic admixtures. Most of the organic admixtures will prolong the hydration induction period, and the corresponding effect on the hydration acceleration period varies greatly. The mainstream influence mechanisms of organic admixture include complexation and adsorption theories. Some new theories such as “self-assembly of hydration products” are also put forward, but need to be further verified.

Surface Chemistry and Molecular Dynamics of Epoxy Resin: Insights from Analysis During Curing and Post-Curing Processes.

The surface chemistry of epoxy resin and its composites is critical for their long-term performance across various applications. In this study, we investigate the main reactions occurring on the surface of DEGBA/DEGBF epoxy resin following curing, post-curing, and thermal post-curing processes using Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS). ToF-SIMS analysis elucidated molecular details, including curing and cross-linking progression, cross-link characteristics, cured resin structure, residual unreacted hardener, cross-linking density, and reaction pathways. Principal Components Regression analysis (PCR) was applied to distinguish between cured and post-cured samples, focusing on specific ions indicative of the curing process. The completion of curing was associated with ions such as C14H7O+, CHO+, CH3O+, and C21H24O4+, while unreacted hardener was indicated by C21H24O4+ ions. Cross-linking density and the intensities of aliphatic hydrocarbons were crucial in differentiating curing stages. Calibration ensured that all ion intensities totaled to one, and specific ions were tracked to monitor the states from uncured to post-cured. Negative spectra provided insights into the consumption of hardener molecules during curing and post-curing. The results demonstrated that post-curing enhances the properties of epoxy resin by promoting further cross-linking, reducing residual unreacted groups, and forming a more extensive covalent network. This results in improved mechanical and thermal stability. The molecular changes observed through ToF-SIMS data effectively distinguish between curing and post-curing reactions, contributing to a better understanding and optimization of epoxy resin properties for various applications.

Flame and flow characteristics of lean premixed turbulent NH3/H2/N2 - air flames with increasing Karlovitz numbers

Premixed flames of partially cracked ammonia (NH3) hold significant promise for the decarbonization of internal combustion engines and gas turbines, since they can burn at a similar laminar flame speed to methane but have notably high blow-out resistance. Understanding turbulent premixed flames with partially cracked NH3 is highly relevant from both academic and application perspectives. This study aims to enhance our understanding of such premixed NH3/H2/N2-air flames subjected to increasing turbulence. For this purpose, a specific fuel mixture, consisting of 40vol% NH3, 45vol% H2, and 15vol% N2, is selected to match the laminar flame characteristics of methane at the same equivalence ratio. Turbulent jet flames are stabilized in a piloted burner with increasing bulk velocities from 30 to 180 m/s and Karlovitz numbers from approximately 75 to 2,140. One-dimensional (1D) simulations of freely propagating flames and strained counter-flow flames are performed, emphasizing temperature and species axial profiles and flame response to strain rate. Further, turbulent flow and flame structures are characterized using simultaneous particle image velocimetry (PIV) and laser-induced fluorescence of OH radicals (OH-LIF) measurements. Flame surface density and curvature distributions are evaluated, revealing the dominant role of turbulence over differential diffusion in shaping the flame surface topology. It is also found that the OH intensity gradient serves as a marker for local reactivity and thermo-diffusive instabilities, being higher at positive curvatures than at negative ones. Flat flames dominate the surface topology but show significant discrepancies in as they appear both upstream and downstream of leading edges. The thickness of the OH layer is not broadened by turbulence, even at Ka = 2,140, suggesting that eddies cannot penetrate into the main reaction zone marked by OH radicals, which are formed at higher temperatures than the preheat layer.

Automatic and simple: how to analyze isothermal calorimetry data of cement hydration quantitatively

Abstract Isothermal heat flow calorimetry is a valuable characterization method for cementitious materials. Although the method is very precise, it is mostly employed qualitatively, i.e., by visual comparison of individual curves in cementitious systems. Here, we present a computer program implemented in Python that facilitates the quantitative determination of characteristic kinetic parameters for a large number (hundreds to thousands) of calorimetry experiments. The usefulness and correctness of the method are demonstrated by the quantitative evaluation of the concentration-dependent influence of three different cement retarders on Portland cement hydration. We find that for the set of sucrose, etidronic acid, and tartaric acid, sucrose causes the strongest retardation of the main hydration reaction. All three retarders exhibit an exponential relationship between the duration of the dormant period and the dosage of the retarder.

Studies of the Catalytic Activity of New Nickel(II) Compounds Containing Pyridine Carboxylic Acids Ligands in Oligomerization Processes of Selected Olefins and Cyclohexyl Isocyanide.

Catalysts based on nickel(II) ions, due to their high reactivity and easiness of ligand modification, are among the most widely used catalytic systems in the world, with applications in a variety of catalytic processes. Herein, research that leads to the synthesis of new nickel(II) complex compounds containing nicotinic and isonicotinic acid ligands is presented. Their catalytic properties have been studied in oligomerization processes of olefins and isocyanides and the obtained oligomers are subjected to qualitative and quantitative analysis to determine their physicochemical properties. The catalytic activity values achieved in the oligomerization of olefins only in a few cases reach above 100 g mmol-1 h-1 bar-1. However, the newly obtained catalytic systems show very high (99%) and moderate (36%) efficiency in the oligomerization of cyclohexyl isocyanide. The conducted studies provide knowledge about the influence of modification of the main ligand and reaction conditions on the values of catalytic activity, process yields, as well as physicochemical properties of the obtained oligomers. Furthermore, it is possible to determine which of the processes carried out using the newly synthesized catalytic systems achieve better results and in which process they should be further used and developed.

Understanding adolescent pregnancy in Ghana: prevalence, reactions, resolution and predictors

BackgroundAdolescence is marked by increased risky sexual activity, which could result in unintended pregnancies. Studies on adolescent pregnancy in Ghana have mainly focused on the prevalence, determinants, and effects to the detriment of the dynamics surrounding parents' and adolescents' reactions to adolescent pregnancy. This study examined the prevalence, parents' and adolescents' reactions, and pregnancy resolution among adolescents aged 10–17. In addition, it examined the predictors of adolescent pregnancy.MethodsSecondary data, which used a convergent parallel mixed approach, was used to study adolescents aged 10–17 in Ghana. The quantitative data involved 382 respondents, while the qualitative data involved 15 adolescent key informants, 15 parent key informants, and 96 adolescent discussants. Descriptive statistics, Pearson's chi-square and Fisher's exact tests, and binary logistic regression were used to analyse the quantitative data. In contrast, thematic analysis was used to analyse the qualitative data.ResultsSlightly more than one-third of adolescents (35.3%) have ever been pregnant. Most adolescents (63.0%) affirmed that they informed their parents about their pregnancy. Adolescents indicated that parents' main reactions to adolescent pregnancy were feelings of disappointment and anger and perceiving pregnancy as normal. Adolescents expressed feelings of shock when they discovered they were pregnant. Regarding pregnancy outcomes, about 26% of adolescents aborted their pregnancy. A lack of sexual and reproductive health education and child marriage emerged as causes of adolescent pregnancy, while adolescent educational level, marital status, ecological zone, religion, and living arrangements were significant predictors of adolescent pregnancy.ConclusionsThis study found that adolescent pregnancy was high (35.3%). According to adolescents, some parents felt disappointed and angered, while others accepted the pregnancy of their children. Due to the high prevalence of pregnancy and lack of knowledge on sexual and reproductive health, we recommend intensifying sexual and reproductive education and services among adolescents in Ghana.

Impact of a pulsed light process on phytosanitary products and ecotoxicity of viticultural wastewaters

Pulsed light (PL) treatment of three viticultural wastewaters (WWs) was performed with increasing fluence from 0 to 91 J/cm2. The evolution of the concentrations of the pesticides was monitored by High-Performance Liquid Chromatography coupled with tandem Mass Spectrometry (HPLC-MS/MS). PL enabled a significant decrease in concentration of the majority of the pesticides present in the wastewaters (WW): 6 out of 12 pesticides were degraded by 62 to 92 % in WW1, 7 out of 10 by over 80 % in WW2, and the only pesticide observed, fluopicolide, was degraded by 87 % in WW3. Only four pesticides were not significantly affected by PL: ametoctradin, benalaxyl, dimethomorph and tebuconazole. PL treatment was found to be less effective on wastewater than on pesticide-spiked deionised water, likely due to the wastewater matrix components absorbing the radiation. Fifteen of the 36 targeted photoproducts were observed following PL treatment of wastewater. The main potential reactions of the halogenated compounds were dehalogenation or substitution of halogen by hydroxyl groups. A photoproduct and possibly natural metabolite of fenbuconazole (m/z 303) was observed in an untreated sample. Acute toxicity tests were performed on the bacteria A. fischeri. A significant reduction in toxicity was observed in the three tested wastewaters: by a factor of 4.1, 6.5 and 4.3 in WWs 1, 2 and 3 respectively. However, the wastewaters remained highly toxic even after the highest fluence applied, probably due to very high copper concentrations in the three wastewaters, and to the absorbance of the samples reducing the degradation efficiency of the PL. Further studies should focus on adapting PL treatment to wastewater; the first step should be a pilot study performed on a semi-industrial scale. Toxicity analyses should be carried out on various freshwater trophic levels to ensure the harmlessness of the process.

Theoretical Kinetic Study of Thermal Decomposition of 5-Methyl-2-ethylfuran.

With the advancement of new synthetic techniques, 5-Methyl-2-ethylfuran (5-MEF) has emerged as a promising renewable biofuel. In this study, the potential energy surfaces for the unimolecular dissociation reaction, H-addition reaction, and H-abstraction reaction of 5-MEF were mapped at the CBS-QB3 level. The temperature- and pressure-dependent rate constants for these reactions on the potential energy surfaces were determined by solving the master equation, using both transition state theory and Rice-Ramsperger-Kassel-Marcus theory. The results showed that the dissociation reaction of the C(6) site on the branched chain of 5-MEF has the largest rate constant and is the main decomposition pathway, while the dissociation reaction of the H atom on the furan ring has a lower rate constant and is not the main reaction pathway. In addition, the dissociation of H atoms on the branched chain and intramolecular H-transfer reactions also have high-rate constants and play an important role in the decomposition of 5-MEF. H-addition reactions mainly occur at the C(2) and C(5) sites, and the generation of the corresponding products through β-breakage becomes the main reaction pathway. With the increase in temperature, the H-addition reaction at the C(2) site gradually changes to a substitution reaction, dominating the formation of C2H5 and 2-methylfuran.

Voluntarily wheel running protects doxorubicin-induced kidney injury by inhibiting oxidative stress through mitochondrial function.

Doxorubicin (DOX) has a broad anticancer spectrum and precise anticancer effects, but its clinical application is limited by severe multiorgan toxicity, among which nephrotoxicity is one of the main adverse reactions. In this study, the protective effect of voluntary wheel running on nephrotoxicity induced by DOX was observed, and its mechanism was initially discussed. Forty male C57BL/6 mice were randomly divided into a control group (CTR), a voluntary wheel running group (EX), a doxorubicin model group (DOX) and a doxorubicin combined with voluntary wheel running group (COM). After 2 weeks of exercise, the mice were sacrificed. Serum creatinine (CREA), urea nitrogen (BUN), uric acid (UA), carbon dioxide combining power (CO2-CP), renal tissue apoptosis, oxidative stress and mitochondrial function indicators were assessed. Compared with those in the DOX group, the concentrations of CREA, BUN and UA decreased, the number of TUNEL-positive cells in kidney tissue decreased, the expression of antiapoptotic proteins increased, and the expression of proapoptotic proteins decreased in the COM group. In addition, the COM can reduce the ROS and MDA contents in kidney tissue, reduce peroxide accumulation and alleviate mitochondrial respiratory chain damage caused by DOX. Voluntary wheel running can improve the mitochondrial function of renal cells and reduce oxidative stress damage, thus playing a protective role against nephrotoxicity caused by DOX. This study provides a new way to reduce the adverse reactions to chemotherapy in combination with the application of chemical drugs.

Structural and anti-ovarian cancer insights into the immunoglobulin G-glabridin nanocomplex.

Structural and anti-ovarian cancer insights into the immunoglobulin G-glabridin nanocomplex.

Відмінність поверхневої структури ізотопів вуглецю, ефекти її впливу на розрахунки перерізів реакції 13С(11В, 10В)14С

Recently published experimental angular distributions of the reaction 13С(11В, 10В)14С at Еlab(11B) = 45.0 MeV for transitions to the ground states of exit channel nuclei, were analyzed within coupled-reaction-channels method (CRC), applying for 10В + 14С interaction the potentials for systems 10В + 12-20С that were obtained by means of the double-folding method (DF) using modelled shapes for the distributions of nucleons in 10В and 12-20С nuclei. This research aimed to investigate the influence of the surface structure of 12-20С isotopes, reflected accordingly in the constructed potentials for the interaction of 10В + 12-20С, on the results of CRC-calculations and their agreement with experimental data. The difference of CRC cross sections for the direct transfer of a neutron, as the main reaction mechanism, was found to be small when applying DF-potentials calculated for systems 10В + 12-16С in the exit channel of this reaction. Only with DF-potentials for 10В + 17-20С systems used in the exit channel of the reaction 13С(11В, 10В)14С a more notable difference of CRC cross sections against the experimental data and those used for the system 10В + 14С was observed, what originates from more diffuse density distributions of nucleons modelled on the surfaces of isotopes 17-20С in comparison with 14С. As CRC-calculations of transfer reactions are affected by strong couplings between different channels, what can deteriorate the investigation of the influence of slight differences in the shapes of DF-potentials in the interaction region, the measurements of angular distributions for the elastic and inelastic scattering of unstable 15-20С isotopes are desirable, as far as possible, for the investigation of their internal structure and isotopic differences.