Oxidation Ratio Research Articles

Chemical characterization and source apportionment of PM2.5 in a Northeastern China city during the epidemic period.

To investigate the influence of COVID-19 lockdown measures on PM2.5 and its chemical components in Shenyang, PM2.5 samples were continuously collected from January 1 to May 31, 2020. The samples were then analyzed for water-soluble inorganic ions, metal elements, organic carbon, and elemental carbon. The findings indicated a significant decrease in PM2.5 and its various chemical components during the lockdown period, compared to pre-lockdown levels (p < 0.05), suggesting a substantial improvement in air quality. Water-soluble inorganic ions (WSIIs) were identified as the primary contributors to PM2.5, accounting for 47% before the lockdown, 46% during the lockdown, and 37% after the lockdown. Ionic balance analysis revealed that PM2.5 exhibited neutral, weakly alkaline, and alkaline characteristics before, during, and after the lockdown, respectively. NH4+ was identified as the main balancing cation and was predominantly present in the form of NH4NO3 in the absence of complete neutralization of SO42- and NO3-. Moreover, the higher sulfur oxidation ratio (SOR) and nitrogen oxidation ratio (NOR), along with the significant increase in PM2.5/EC, suggested intense secondary transformation during the lockdown period. The elevated OC/EC ratio during the lockdown period implied higher secondary organic carbon (SOC), and the notable increase in SOC/EC ratio indicated a significant secondary transformation of total carbon. The enrichment factor (EF) results revealed that during the lockdown, 9 metal elements (As, Sn, Pb, Zn, Cu, Sb, Ag, Cd, and Se) were substantially impacted by anthropogenic emissions. Source analysis of PMF was employed to identify the sources of PM2.5 in Shenyang during the study period, and the analysis identified six factors: secondary sulfate and vehicle emissions, catering fume sources, secondary nitrate and coal combustion emissions, dust sources, biomass combustion, and industrial emissions, with secondary sulfate and vehicle emissionsand catering fume sourcescontributing the most to PM2.5.

CO2-Free Ethylene Oxide Production via Liquid-Phase Epoxidation with Fe2O3/MSM Catalyst.

In this study, we present an approach for ethylene oxide (EO) production that addresses environmental concerns by eliminating greenhouse gas emissions. Our catalyst, Fe2O3/MSM, was synthesized using a hydrothermal method, incorporating Fe2O3 nanoparticles into a well-structured mesoporous silica matrix (MSM). We selected peracetic acid as the oxidant, enabling CO2-free EO production while yielding valuable by-products such as acetic acid, monoethylene glycol, and diethylene glycol. X-ray diffraction (XRD), X- ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET) analyses confirmed the heteroatom structure of the catalysts and porosity, while Transmission electron microscopy (TEM) analysis provided insights into its morphology. Then, the synthesized catalyst was used in the liquid-phase epoxidation of ethylene for EO production. Our systematic experiments involved varying critical parameters such as temperature, ethylene to oxidant ratio, catalyst dosage, and solvent to optimize EO selectivity and ethylene conversion. The results of this study demonstrated an 80.2 % ethylene conversion to EO with an EO selectivity of 87.6 %. The production process yielded valuable by-products without CO2 emissions, highlighting its environmental friendliness.

Pollution characteristics and transformation mechanisms of secondary inorganic components during winter heavy pollution in Handan city in 2018–2020

The mechanism of secondary transformation of nitrate and sulfate under different relative humidity (RH), and different atmospheric oxidizing conditions is still controversial. This study focuses on the winter heavy pollution process in Handan city from 2018 to 2020, and the following results were obtained: The average concentration of PM2.5 showed a decreasing trend from year to year, but the SNA (SO42−, NO3− and NH4+) showed an increasing trend from year to year, and the concentration of nitrate exceeded that of sulfate. During the haze formation period from 2018 to 2020, a significant disparity was observed in NO2 and SO2 emissions, with NO2 emissions surpassing those of SO2. Mobile sources were found to contribute more emissions than fixed sources, particularly during the haze persistence period (HP). However, sulfate conversion outweighed nitrate conversion. HighRH and photochemical reactions induced by ozone favored the formation of nitrate and sulfate, which formated heavy haze. When 40% ≤ RH ≤ 70%, atmospheric oxidants (Ox = O3 + NO2) concentration was the highest, nitrogen oxidation ratio (NOR) and sulfur oxidation ratio (SOR) increased rapidly, and nitrate was mainly generated by photochemical reactions during daytime. When RH > 70% and the concentration of Ox was low, RH will weaken the photochemical intensity. Therefore, the liquid-phase oxidation reaction of N2O5 contributed significantly to atmospheric nitrate at night, and the liquid-phase oxidation reaction of sulfate was faster than the gas-phase one. Local emissions contributed significantly to particulate matter pollution during heavy pollution in 2018–2020, and the main sources were secondary conversion, coal combustion, biomass burning, and road dust.

Association of impulsive behavior and cerebrospinal fluid/plasma oxidation and antioxidation ratio in Chinese men

ObjectivesImpulsive behavior is the precursor of many psychiatric and neurological conditions. High levels of impulsive behavior will increase health risk behavior and related injuries. Impulsive behavior is produced and regulated by central and peripheral biological factors, and oxidative stress (OS) can aggravate it. However, previous studies only showed that impulsive behavior was related to the level of the peripheral OS. Therefore, this study aims to clarify the relationship between OS and impulsive behavior in the brain and peripheral blood. MethodsWe recruited 64 Chinese men. We measured superoxide dismutase (SOD) (including copper, zinc and manganese) and nitric oxide synthase (NOS) (including total, inducible and constitutive) in cerebrospinal fluid (CSF) and plasma. The Barratt Impulsiveness Scale version 11 (BIS-11) was used to evaluate impulsive behavior. The relationship between OS and impulsive behavior was evaluated by partial correlation analysis and stepwise multiple regression analysis. ResultsPartial correlation analysis showed that the ratio of total NOS-to-MnSOD and iNOS-to-MnSOD in CSF were negatively correlated with the BIS-11 motor scores (r = −0.431, p = −0.001; r = −0.434, p = −0.001). Stepwise multiple regression analysis showed that the ratio of CSF iNOS-to-MnSOD was the most influential variable on the BIS-11 motor scores(β = −0.434, t = −3.433, 95 %CI(−0.374, −0.098), p = 0.001). Conclusions and RelevanceThe imbalance of central oxidation and antioxidation is related to impulsive behavior, which broadens our understanding of the correlation between impulsive behavior and OS.

Size-resolved water-soluble organic carbon and its significant contribution to aerosol liquid water

Size-segregated aerosols collected in Beijing from 2021 to 2022 were used to investigate the contribution of organic aerosols to the aerosol liquid water content (ALWC), the influencing factors of ALWC, and the concentrations and size distribution characteristics of water-soluble organic carbon (WSOC) after clean air actions. The results showed that the concentration of WSOC in particulate matter (PM)1.8 was 3.52 ± 2.43 μg/m3 during the sampling period. Obvious changes were observed in the size distribution of WSOC after clean air actions, which may be attributed to the enhancement of atmospheric oxidation capacity and the decrease in PM concentration. The contribution of organic aerosols to the ALWC in fine PM was 18.1 % during the sampling period, which was more significant at lower particles concentration and smaller particle size ranges. The ambient relative humidity (RH) and the ratio of NO3−/SO42− had an apparent influence on ALWC. The continuous increase in the nitrate proportion significantly reduced the deliquescence point of the aerosols, making them prone to hygroscopic growth at lower RH. Analysis of the relation among nitrogen oxidation ratio (sulfur oxidation ratio), ALWC and PM1.8 mass concentrations suggests that organic matter has a significant effect on the formation of secondary inorganic aerosols in the initial phase of pollution formation and plays a crucial role in aerosol pollution formation in Beijing. These results are conducive to understanding the formation mechanism of aerosols and provide scientific data and theoretical support for the formulation of more effective emission-reduction measures.

High-Precision Measurement of the 238Pu/239Pu Isotope Ratio by TIMS.

With an aim to improve the precision of isotopic standards of special nuclear materials like uranium and plutonium, National Bureau of Standards (NBS) undertook the recertification of isotopic standards prepared between 1960 and 1970. In a recent initiative, Lawrence Livermore National Laboratory (LLNL) in collaboration with New Brunswick Laboratory Program Office (NBL PO) undertaken efforts to recertify SRM 946, SRM 947, and SRM 948. The primary goal of this drive is to lower the uncertainties associated with the isotopic compositions of plutonium standards. The drive is also aims to minimize the uncertainty associated with measurement of the 238Pu content from 2% to ∼0.3%. In this connection, our laboratory at the Fuel Chemistry Division, Bhabha Atomic Research Centre, proposes a novel indicator "minima in the (RMO254/(i+16))/(RM238/i) curve" (where i = m/z 233 or 235 amu), which is the ratio of the isotope ratio of metal oxides (238M16O/iM16O) to that of metal ions (238M/iM) of uranium in determining the accurate 238Pu content by thermal ionization mass spectrometry. Various enriched uranium spikes have been employed to study the efficacy of the minima in the (RMO(254)/(i+16))/(RM238/i) curve. With the combination of monitoring the minima in the (RMO(254)/(i+16))/(RM238/i) curve and the application of the 233U spike (with an isotope abundance of 238U ∼ 0.05%), an external precision of 0.2% has been achieved in the determination of the 238Pu/239Pu isotope ratio for isotopic standard SRM 947.

Silicon-based waveguide technology for millimeter-wave antennas

This paper describes a method for the preparation of complex structured waveguides that can be used for millimeter-wave antennas based on a bulk silicon MEMS process. In this paper, a millimeter-wave band array of ridge waveguide slit antennas with multilayer step-matched feeds is realized by this method. A bulk silicon MEMS process is used to realize the complex structure and the high precision and flatness requirements on the millimeter scale, which cannot be achieved by machining. And the step height difference of more than 100um is realized by combining multiple lithography and silicon oxide mask. The step difference is larger than that achievable by dry etching using the etching selection ratio of silicon oxide and silicon. The waveguide fabricated by this method can work well in the millimeter wave band and is used for antenna feeding, power distribution, etc. It is characterized by compact structure, high precision, and high performance.

Lotus Root Type Nickel Oxide-Carbon Nanofibers: A Hybrid Supercapacitor Electrode Material

In this study, we investigate the electrochemical properties of a nickel oxide-carbon (NiO/C) material, synthesized in the form of highly porous carbon nanofibers through the electrospinning of polymers such as polyacrylonitrile (PAN) and polystyrene (PS) followed by a carbonization process. The primary focus of this work is to determine the optimal mixing ratio for the hybrid material composed of NiO and carbon. While it is widely acknowledged that supercapacitor materials benefit from having a high specific surface area, our findings reveal that hybrid carbon nanofibers with a 45% specific carbon-to-nickel oxide ratio exhibit significantly enhanced capacitance (39.9 F g−1). This outcome suggests the promising potential of our materials as an energy storage material for hybrid supercapacitors, combining the advantages of electric double-layer capacitors (EDLC) and Pseudo capacitors (Pseudo).

Comparing the Effect of In2O3 and Eu2O3 Impurities on the Structural and Optical Properties of Cerium Oxide

This work compares the changes in optical and structural properties of cerium oxide (CeO2) when doped with different concentrations (3%,5%,7%, and 9%) of two oxides, In2O3 and Eu2O3. X-ray diffraction and spectrophotometry were employed in the visible, ultraviolet, and near-infrared regions. The findings demonstrated that CeO2 doped with In2O3 and Eu2O3 thin films were polycrystalline and had a cubic structure. The crystal size increased from 20.5 to 32.15 when Eu2O3 doping ratio increased from 0% to 7% and then decreased to 28.46 nm at 9%. While the crystal size showed an increase from 20.5 to 21.42 nm with the increase of the In2O3 doping ratio, while the lattice constant measured for cubic CeO2 changed opposite to that. The optical measurement showed that Eu2O3 and In2O3 doped CeO2 thin films have a direct band gap with allowed transition with 3.0 eV for the undoped CeO2. The band gap energy changed in a non-regular manner with the increase of the doping ratio of both oxides. The minimum band gap energy was 1.2 eV obtained for 7% Eu2O3 doped CeO2 thin film, and the minimum band gap energy was 1.4 eV obtained for 9% In2O3 doped CeO2. These results qualify them for use as absorbers in solar cell applications.

Salt-resistant and antibacterial polyvinyl alcohol/chitosan/silver-loaded graphene oxide electrospun nanofiber membrane for high-efficiency solar-driven desalination

To address the issues of low photothermal conversion efficiency, salt deposition and biological contamination in solar-powered desalination, we have developed nanofibrous membranes composed of an optimized ratio of silver-loaded graphene oxide (GO-Ag) composites and polyvinyl alcohol/chitosan (PVA/CS), using a simple and productive electrospinning technique. The synergistic effect of GO and Ag significantly enhanced the photothermal conversion efficiency of the dual-photothermal PVA/CS/GO-Ag-4% electrospun nanofiber membranes (EFMs), which achieved the pure water evaporation rate of 1.67 kg m−2 h−1 and photothermal conversion efficiency of 93.3% under 1 sun (1 kW m−2). Notably, 97% of optical energy is converted to heat when the PVA/CS/GO-Ag-4% EFMs were placed on a homemade evaporation device, achieving up to a simulated seawater evaporation rate of 1.64 kg m−2 h−1 under 1sun, with a desalination rate of 99.99%. More importantly, larger area EFMs are easier to prepare compared to other morphologies of solar evaporators, and larger membranes can be placed on outdoor evaporation units for large-scale effective desalination of seawater used to collect fresh water under natural light. Furthermore, PVA/CS/GO-Ag-4% EFMs exhibited outstanding antibacterial performance against Escherichia coli and Staphylococcus aureus. Considering these strengths, the PVA/CS/GO-Ag-4% EFMs has considerable application potential in solar-driven desalination to solve water crises.

Size-selective attachment of polyvinyl chloride microplastics on iron oxides in aqueous environments

The interaction of microplastics (MPs) with mineral particles is a crucial process determining the fate of MPs in aquatic environments, but potential size-selective interaction of MPs with minerals is unknown. In this work, strong and multi-layered attachment of a mix of heterogeneously size of polyvinyl chloride (PVC) MPs was observed on all the four types of iron oxides, following an order of Fe3O4-i > Fe3O4-s > γ-Fe2O3 > Fe3O4-n. Electrostatic attraction dominated their strong attachment, while hydrogen bonding and halogen bonding also contributed to MPs-mineral interaction. Importantly, both attachment rates and capacities were more favorable for large-sized PVC MPs (> 1.0 μm) than small-sized MPs (0.6–1.0 μm), due to more available attachment sites and stronger electrostatic attraction. Large-sized MPs preferred to detach from iron oxides before small-sized MPs, confirming by configuration analysis. The attachment accelerated the sedimentation of PVC MPs, while a fraction (i.e., 26.7 %, PVC/iron oxide ratio at 0.2:1) of heteroaggregates floated at the air–water interface associated with bubbles. Natural organic matter decreased MPs-mineral interaction due to competitive adsorption, electrostatic repulsion, and steric hindrance, while the attachment was enhanced with increasing ionic strengths (0–200 mM). These findings contribute to a better understanding of the transport and fate of MPs in aquatic systems.

Efficiently removing dissolved organic pollutants in landfill leachate concentrate using dual-anode Fe2+/HClO system: The significance of insolubilization based on oxidative coupling of organics

The strategy to mineralize dissolved organics for the decontamination of landfill leachate concentrate (LLC) is expensive. Because mineralization requires high stoichiometric ratio of oxidants (e.g., •OH) or electron transfer (i.e., energy) to the pollutant molecules. Whereas, transferring the dissolved organic pollutants into separable insoluble matters is an energy-saving strategy. Herein, we developed a dual-anode Fe2+/HClO system for removing dissolved organic pollutants in LLC through insolubilization based on oxidative coupling. In this system, the majority of dissolved organic pollutants were transferred into insoluble substances, which could be removed easily. As a result, 89.8 % of the dissolved organic carbon (DOC) in LLC was fast removed in 3 h with a low specific energy consumption (SEC, 4.0 kWh kg−1 COD and 17.6 kWh kg−1 DOC), and the formation of toxic by-products can be well controlled to total organic chlorine (TOCl) < 0.1 mg/L. The formation of insoluble substances was attributed to the oxidative coupling of organic small molecules into the macromolecular ones. This was evidenced by the generation of insoluble compounds with the larger molecular mass, and the formation of coupling or polymerization products of the model pollutant (guaiacol). The predominant mechanism was proposed that Fe(IV) was generated in the dual-anode Fe2+/HClO system, and Fe(IV) oxidized pollutants to produce organic radicals, then the organic radicals coupled and polymerized to form larger molecules and insoluble compounds. This work offers a novel electrochemical method for efficient removal of organic pollutants in LLC with minimal toxic by-products generated, and revealed the significance of oxidative coupling process in the electrochemical Fe2+/HClO system.

Abstract 759: Soy protein diet changes metabolic profile in liver of 7,12-dimethylbenz(α)anthracene (DMBA)-induced mammary tumors in obese zucker rats

Abstract Obesity is associated with the risk of certain types of cancers development including breast cancer. Previously, we reported that obesity increased mammary tumor development using obese Zucker rat model. Several studies have shown the health benefit of soy protein consumption. However, the effects of soy protein diet on liver of mammary tumor for oxidative stress and DNA reaction is less known. We used DMBA induced-mammary tumor model to investigate the effects of soy protein diet on pro-oxidative environment and oxidative DNA modification in liver of obese DMBA mammary tumors rats. Female obese zucker rats (n=45) were either fed casein as control (OC; n=20) or soy protein isolate (OS; n=25), received DMBA (65mg/kg BW) at the age 50 days and sacrificed 20 weeks later. We used HPLC-ECD, HPLC-UV and LC-MS techniques for liver metabolic analysis. Comparing liver of OS vs. OC, soy protein 1) decreased the level of Methionine (P&amp;lt;0.02), increased 2) free reduced Homocysteine (P&amp;lt;0.02), 3) S-Adenosylmethionine (SAM, P&amp;lt;0.03), 4) S-Adenosyhomocysteine (SAH, P&amp;lt;0.001) and 5) 5methyl-Cytosine (5mC, P&amp;lt;0.03). Also, soy protein decreased (P&amp;lt;0.003) level of free oxidized Glutathione (GSSG), increased (P&amp;lt;0.02) GSH/GSSG oxidative stress ratio, without any changes a level of free reduced Glutathione (GSH), followed decrease (P&amp;lt;0.04) in liver DNA level of 8-OH-Guanosine (8-OH-G) and level (P&amp;lt;0.02) of 5hmethyl-Cytosine (5hmC). Our results shows soy protein diet capable change liver metabolism: a. Modify a methylation status by increasing levels of SAM (universal methyl group donor) following global liver DNA hypermethylation (5mC), and SAH (methylases inhibitor); b. Alleviate level of oxidative stress in liver by decreasing level of GSSG (not active glutathione), increasing GSH/GSSG ratio (antioxidative capacities), following lower ROS liver DNA damages by decrease levels of 8-OH-G and 5hmC. In conclusion, using obese DMBA-induced mammary tumor Zucker rat model, soy diet making a complex and significantly modification of metabolic conditions in liver affecting both methionine cycle and transsulfuration metabolic pathways. Citation Format: Reza Hakkak, Stepan Melnyk. Soy protein diet changes metabolic profile in liver of 7,12-dimethylbenz(α)anthracene (DMBA)-induced mammary tumors in obese zucker rats [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 759.

Enhancement in antimicrobial efficacy and biodegradation of natural rubber latex through graphene oxide/nickel oxide nanoparticles

This work aims to fabricate antibacterial natural rubber latex composites by introducing different ratios of graphene oxide (GO) and nickel oxide (NiO) nanoparticles. The nanocomposites were prepared using latex mixing and a two-roll mill process, followed by molding with a heating hydraulic press. Detailed analyses were conducted to evaluate the rheological, chemical, physical, thermal, mechanical, and electrical performance of the composites. Fourier transform infrared spectroscopy (FTIR) was employed to analyze the interaction among different components, while the surface morphology was examined through the field emission scanning electron microscopy (FESEM) technique. The composites with a loading ratio of 1:2 of GO to NiO (optimized concentration) exhibited the highest tensile strength (24.9 MPa) and tear strength (47.4 N/ mm) among all the tested samples. In addition, the composites demonstrated notable antimicrobial activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans. The thermal stability of the composites was observed up to 315 °C, and their electrical resistivity lies in the insulating range across a temperature span of 25 °C to 50 °C. The research uncovers critical insights into advancing composite materials suitable for diverse applications, featuring inherent antibacterial attributes, robust mechanical properties, resilience to solvent, UV shielding properties, and controlled electrical resistivity capabilities.

Random Terpolymer of Carbon Dioxide, Butadiene and Epoxides: Synthesis, Functionalization and Degradability

Comprehensive SummaryThe utilization of carbon dioxide (CO2) as a C1 feedstock is consistently attractive, especially in the preparation of sustainable polymeric materials. In this contribution, a terpolymer of CO2, 1,3‐butadiene (BD) and epoxide is synthesized by scandium triflate catalyzed cationic ring‐opening copolymerization of α‐ethylidene‐δ‐vinyl‐δ‐valerolactone (EVL), an intermediate derived from CO2 and BD, with epoxides. The obtained terpolymer with a CO2 content of 22 mol% has a number‐average molecular weight (Mn) up to 7.8 kg/mol and a dispersity (Đ) of 2.4. The reactivity ratios of EVL and cyclohexene oxide (CHO) are determined as 0.01 and 1.07, respectively, suggesting random characteristic of the terpolymer. The preserved C=C double bonds from BD allow for the further modification of the terpolymer by photoinitiated crosslinking. The yielded networks are fluorescent and degradable. This method offers enhanced versatility to the synthesis and additional functionalization of CO2‐based polymers.

Pivotal Role of Salicylates in Tuning the Formation and Reactivity of Mn(V)=O's

AbstractAn alternative and efficient route has been derived to generate the high valent [Mn(V)=O(m‐Cl‐salicylate)]+ intermediates with a series of non‐heme neutral ligand frameworks at 20 °C. The current method provides an advantage with feasibility in maintaining stoichiometric oxidant ratios along with the crucial variations of the salicylate moieties in tuning the reactivity of Mn(V)=O species. An in‐depth analysis of the Hammett studies revealed that the bound 5‐X‐salicylate (X=Cl, and NO2) drastically alters the corresponding Mn(V)=O's reactivity rates. In contrast, variations in the parent ligand frameworks resulted in consistent ρ values with increased lifetimes depicting the ligand's role in stabilization. Lastly, the complexes have been characterized to promote oxidative stress and prevent the proliferation of cancer cells effectively.

Some lithogeochemical and isotope-geochemical features of clay rocks and hiatuses in the Riphean stratotype

Research subject. Clay rocks of the Lower, Middle, and Upper Riphean (respectively, the Burzyan, Yurmatau, and Karatau groups) of the Western slope of the Southern Urals. Changes in their characteristic values of a number of ratios of oxides and some trace elements that are indicators of rock composition in provenances are considered, taking into account the breaks of different duration present in the Riphean stratotype. Methods. Calculation of t he average values of TiO2/Al2O3, Th/Sc, La/Co and (La/Yb)N, typical for shales, fine-grained clay siltstones, and mudstones of the main lithostratigraphic units of the Riphean stratotype (formation and, in some cases, subformation) and analysis of their changes taking into account the hiatuses known in the Riphean stratotype (Pre-Mashak/Pre-Zigalga, Pre- Zilmerdak, Pre-Minyar, Pred-Uk). Results. It was established that throughout the entire Riphean, regardless of breaks in sedimentation, presumably associated with certain transformations in the areas of erosion and sedimentation, a number of lithogeochemical characteristics of fine-grained clastic rocks of the Burzyan, Yurmatau, and Karatau groups (such as TiO2/Al2O3, Th/Sc, La/Co, and, to a significant extent, (La/Yb)N) practically did not experience significant changes. Conclusions. The data obtained give reason to think that there were no fundamental changes in the composition of the sources of fine-grained aluminosiliciclastics for the Riphean sedimentary sequences for more than 1 Ga, and contradict the rather active scenario of tectonic processes at the end of the Early Precambrian and the entire Late Precambrian. Conversely, the data on the values of tNd(DM) and eNd(t) in 37 samples of clay rocks of the Riphean stratotype nevertheless reflect a change in the composition of the rocks of the feeding provinces and, one way or another, fit into the outline of subglobal events established by conventional geological methods in the stratotype area of the Riphean. In accordance with them, in the Ai and Mashak times, an increase in the proportion of juvenile material took place in the areas of erosion. Apparently, the Pre-Zilmerdak hiatus also led to the appearance of a significant proportion of basic igneous rocks among the rocks of the provenances.

Impact of Suramin on Key Pathological Features of Sporadic Alzheimer's Disease-Derived Forebrain Neurons.

Alzheimer's disease (AD) is characterized by disrupted proteostasis and macroautophagy (hereafter "autophagy"). The pharmacological agent suramin has known autophagy modulation properties with potential efficacy in mitigating AD neuronal pathology. In the present work, we investigate the impact of forebrain neuron exposure to suramin on the Akt/mTOR signaling pathway, a major regulator of autophagy, in comparison with rapamycin and chloroquine. We further investigate the effect of suramin on several AD-related biomarkers in sporadic AD (sAD)-derived forebrain neurons. Neurons differentiated from ReNcell neural progenitors were used to assess the impact of suramin on the Akt/mTOR signaling pathway relative to the autophagy inducer rapamycin and autophagy inhibitor chloroquine. Mature forebrain neurons were differentiated from induced pluripotent stem cells (iPSCs) sourced from a late-onset sAD patient and treated with 100μM suramin for 72 h, followed by assessments for amyloid-β, phosphorylated tau, oxidative/nitrosative stress, and synaptic puncta density. Suramin treatment of sAD-derived neurons partially ameliorated the increased p-Tau(S199)/Tau ratio, and fully remediated the increased glutathione to oxidized nitric oxide ratio, observed in untreated sAD-derived neurons relative to healthy controls. These positive results may be due in part to the distinct increases in Akt/mTOR pathway mediator p-p70S6K noted with suramin treatment of both ReNcell-derived and iPSC-derived neurons. Longer term neuronal markers, such as synaptic puncta density, were unaffected by suramin treatment. These findings provide initial evidence supporting the potential of suramin to reduce the degree of dysregulation in sAD-derived forebrain neurons in part via the modulation of autophagy.

EFFECT OF CeO2 NANOPARTICLES ON THE STRUCTURAL AND OPTICAL PROPERTIES OF (SnO2:Pd) FILMS PREPARED BY PLD TECHNIQUE

In this paper, pure and doped (SnO2:Pd ) films with CeO2 nanoparticles prepared by PLD technique using a highly intense Nd:YAG laser beam at 600 mJ with a frequency of second radiation at 1064 nm (pulse width 9 ns) repeating frequency (6 Hz) for 400 laser pulses incident on the intended surface has been performed. The stabilized (SnO2:Pd) doped with cerium oxide were used for deposition of the thin films on glass with thickness 200nm±05. Films of SnO2:pd were prepared with different doping concentrations of CeO2(0, 0.05, 0.10,0.15,0.20 and 0.25) wt. The FTIR and UV-Visible spectrophotometer were employed to investigate the structural, and optical characteristics of the films, respectively. FTIR spectra of (SnO2:Pd)1-xCeO2x thin films show seven peaks were assigned at wavenumber range from 2869.73 cm-1 belong to stretching bond CH2 to 492.98 cm-1 belong to N-O which can be indicated by the vibrations mode .The optical results show that transmittance decreased drastically by increasing the doping ratio. In contrast with absorbance, it increased by increasing of the doping ratio of cerium oxide. The optical energy gap was found to change systematic sequence with increasing of CeO2 concentration. Also the optical constant with different CeO2 contents were determined..

Streamlined synthesis of iron and cobalt loaded MCM-48: High-performance heterogeneous catalysts for selective liquid-phase oxidation of toluene to benzaldehyde

Hydrothermal synthesis of MCM-48 molecular sieves featuring the incorporation of both iron and cobalt with Si/M ratios of 20, 40 and 80 (where M represents either iron or cobalt) was performed using tetraethyl orthosilicate as the silica source and cetyltrimethylammonium bromide as a template. To gain a comprehensive understanding of the synthesized materials, these were thoroughly characterized using various techniques, including XRD, XPS, UV–Vis (DRS), FT-IR, N2 adsorption-desorption analysis, SEM with EDX, TEM, TGA and NH3-TPD analysis. XRD analysis revealed the presence of well-ordered MCM-48 structure in the metal-incorporated materials, while XPS and UV–Vis DRS confirmed the successful partial incorporation of metal ions precisely in their desired tetrahedral coordination within the framework. To assess their catalytic performance, we studied the activity and selectivity of these catalysts in liquid phase oxidation of toluene using tert-butyl hydroperoxide as the oxidant. Under optimized conditions, employing a 6% (w/w) Fe-MCM-48 (40) catalyst and maintaining a toluene to oxidant molar ratio of 1:3 at 353 K in a solvent-free environment for 8 h, the oxidation reaction resulted in the formation of benzaldehyde (88.1%) as the major product and benzyl alcohol (11.9%) as the minor product.