Decrease In Concentration Research Articles

Measured air quality impacts after teaching parents about cooking ventilation with a video: a pilot study

Abstract Background Cooking-related emissions contribute to air pollutants in the home and may influence children’s health outcomes. Objective In this pilot study, we investigate the effects of a cooking ventilation intervention in homes with gas stoves, including a video-based educational intervention and range hood replacement (when needed) in children’s homes. Methods This was a pilot (n = 14), before-after trial (clinicaltrials.gov #NCT04464720) in homes in the San Francisco Bay Area that had a school-aged child, a gas stove, and either a venting range hood or over-the-range microwave/hood. Cooking events, ventilation use, and indoor air pollution were measured in homes for 2–4 weeks, and children completed respiratory assessments. Midway, families received this intervention: (1) education about the hazards of cooking-related pollutants and benefits of both switching to back burners and using the range hood whenever cooking and (2) ensuring the range hood met airflow and sound performance standards. The educational intervention was delivered via a video developed in conjunction with local youth. Results We found substantially increased use of back burners and slight increases in range hood use during cooking after intervening. Even though there was no change in cooking frequency or duration, these behavior changes resulted in decreases in nitrogen dioxide (NO2), including significant decreases in the total integrated concentration of NO2 over all cooking events from 1230 ppb*min (IQR 336, 7861) to 756 (IQR 84.0, 4210; p < 0.05) and NO2 collected on samplers over the entire pre- and post-intervention intervals from 10.4 ppb (IQR 3.5, 47.5) to 9.4 (IQR 3.0, 36.1; p < 0.005). There were smaller changes in PM2.5, and no changes were seen in respiratory outcomes. Impact This pilot before-after trial evaluated the use of a four-minute educational video to improve cooking ventilation in homes with gas stoves and one or more school-aged children. Participant behavior changed after watching the video, and there were decreases in indoor air pollutant concentrations in the home, some of which were significant. This brief video is now publicly available in English and Spanish (wspehsu.ucsf.edu/projects/indoor-air-quality), and this provides suggestive evidence of the utility of this simple intervention, which could be particularly beneficial for households that have children with asthma.

The epidemiological characteristics of invasive pulmonary aspergillosis and risk factors for treatment failure: a retrospective study

ObjectiveThe incidence of invasive pulmonary aspergillosis (IPA) is increasing gradually. This study analysed the epidemiological characteristics and prognostic factors of patients with IPA and explored the risk factors affecting prognosis.Materials and methodsThe clinical data and treatment of 92 patients with IPA were retrospectively analysed, and the patients were followed for 12 weeks. Patients were divided into an effective treatment group and an ineffective treatment group, and the risk factors affecting prognosis were discussed.ResultsA total of 92 patients met the IPA inclusion criteria, and the most common genus of Aspergillus was Aspergillus fumigatus. The incidence of IPA was highest in patients with malignant tumours. IPA often coexisted with infections caused by other pathogens. We divided the patients into an effective treatment group and an ineffective treatment group according to prognosis. Compared with those in the effective treatment group, the procalcitonin (PCT) level, lactate dehydrogenase-to-albumin ratio (LDH/ALB) and neutrophil-to-lymphocyte ratio (NLR) in the ineffective treatment group were greater, the serum albumin level was lower, and the imaging findings revealed less nodules and bronchial wall thickening (P < 0.05). Among these factors, a decrease in the serum albumin concentration, an increase in the PCT level, coinfection and less bronchial wall thickening on imaging were independent risk factors for aspergillosis treatment failure.ConclusionA decreased albumin level, an elevated PCT level, coinfection, and less bronchial wall thickening were independent risk factors for treatment failure in patients with IPA. Attention should be given to the albumin level, coinfection status and imaging findings of patients.

Association between mental health and male fertility: depression, rather than anxiety, is linked to decreased semen quality

BackgroundInfertility is increasingly recognized as a global health issue affecting couples of reproductive age, with male factors contributing to approximately 50% of infertility cases. However, the association between depression and anxiety-two of the most prevalent mental health conditions-and impaired male fertility remains a subject of ongoing debate.MethodsIn this cross-sectional study, male participants seeking fertility counseling at an IVF clinic were recruited. Symptoms of depression and anxiety were assessed using the Patient Health Questionnaire-9 (PHQ-9) and the Generalized Anxiety Disorder-7 (GAD-7), respectively. Generalized linear regression models (GLMs) were employed to investigate the relationships between mental health status and semen parameters.ResultsStatus of depression was negatively associated with semen quality parameters, whereas no statistically significant association was recognized between anxiety and semen quality except that sperm concentration was decreased by 25.60 (95% CI, 1.226 to 49.965, P=0.040) ×106/ml in moderate to severe anxiety group referring to normal group. Furthermore, when stratified by sleep duration, moderate to severe depression group showed a great decrease in progressive motility (PR), total motility, concentration and total sperm count (TSC) as referred to normal group in participants with sleep duration less than 7 hours.ConclusionThe present study revealed that depression rather than anxiety was a negative factor that affected semen quality, especially in individuals with shorter sleep duration.

High-performance cold-source field-effect transistors based on Cd3C2/ boron phosphide heterojunction

To overcome the short-channel effect and large gate leakage current in the field-effect transistors (FETs), some cold-source materials have been suggested as alternative materials. We explore the performance of FET based on the cold-source material Cd3C2 using the ab initio quantum transport method. It is shown that the figure of merits (FOMs) of Cd3C2/ Boron phosphide (BP) FET satisfies the requirements of ITRS2028 HP for UL=2 and UL=3nm. The performance of Cd3C2/BP FET is improved when Cd3C2 is p-type doped. Doping causes a super-exponential decrease in carrier concentration, thus the cold-source FET based on Cd3C2/BP is formed. When the doping concentration reaches 10.0 × 1013cm−2, the device satisfies the requirements of ITRS2028 HP. More importantly, at the doping concentration of 10.0 × 1013cm−2 for UL=2 and 3 nm, the subthreshold swings are 52.32 and 56.84 mV/dec, which are lower than 60 mV/dec. This work proposes a new cold-source FET based on Cd3C2/BP, whose excellent performance can make it a competitive candidate in future electronic devices.

Impacts of Buoyancy and Joule Heating on Unsteady MHD Fluid Flow Along a Semi‐Infinite Vertical Porous Plate With Dufour, Chemical Reaction, and Radiation Effect

ABSTRACTAn analytical solution for unsteady, incompressible, laminar MHD fluid flow involving mass and heat transfer along a semi‐infinite vertical moving flat plate in a porous medium have been studied in this paper. Effects of heat radiation and absorption, Joule heating, Dufour, thermal and solutal buoyancy, and first order chemical reaction of are discussed under suitable physical conditions. It is postulated that the plate will migrate in the fluid's motion's direction due to the presence of a uniform magnetic field normal to the porous surface. The regular perturbation technique is used to solve the dimensionless governing equations. The mathematical derivations for fluid velocity, temperature, and concentration are evaluated; apart from that, skin friction, rate of mass and heat transfer at the plate are also expressed. The present outcomes are compared with previously obtained results and are found to be in excellent agreement. It is observed that the fluid velocity and temperature enhanced with thermal and solutal buoyancy forces as well as the Dufour effect. Also, with an increase in chemical reaction parameter, there is a decrease in fluid velocity, temperature, and concentration. Skin friction and Nusselt number increase with higher heat absorption parameter values. Schmidt number and chemical reaction parameter both lead to a rise in Sherwood number. Applications for these models have been observed in a number of industrial and technical methods.

Influence of air pollution on the nonaccidental death before and after the outbreak of COVID-19

BackgroundDuring the COVID-19 pandemic, non-therapeutic interventions (NPIs), such as traffic restrictions, work stoppages, and school suspensions, have led to a sharp decline in the concentration of air pollutants in the epidemic sites. However, few studies focused on the impact of air pollutant changes on the risk of nonaccidental death.MethodWe selected Yancheng City, China, as the study site and applied a Generalized Additive Model (GAM) based on the quasi-Poisson distribution to evaluate the impact of atmospheric pollutants exposure on the nonaccidental death of local residents. The time span of this study was set from January 1, 2013, to December 21, 2022, that is, before and after the outbreak of COVID-19.ResultsThe concentration of some air pollutants has greatly varied after the outbreak of COVID-19, with a significant decline for PM2.5 (− 43.4%), PM10 (− 38.5%), SO2 (− 62.9%), and NO2 (− 22.6%), but an increase for O3 (+ 4.3%). Comparative analysis showed that PM2.5 contributed to an increased risk of nonaccidental death after the outbreak of COVID-19. With an increase in PM2.5 by 10 µg/m³, the excess relative risks (ER) of nonaccidental death of residents increased by 1.01% (95%CI: 0.19%,1.84%). The stratified analysis revealed that air pollutants impacted nonaccidental deaths in both men and women before the outbreak of COVID-19. After the outbreak of COVID-19, PM10 had a significant effect on male nonaccidental deaths. The concentrations of PM2.5, PM10, and SO2 increased by 10 µg/m³, the ER of PM2.5, PM10, and SO2 on female nonaccidental death increased by 1.52% (0.38%,2.67%), 0.58% (0.02%,1.13%), and 15.09% (5.73%,25.28%), respectively. Before the outbreak of COVID-19, five air pollutants had an impact on the death of residents from cardiovascular disease (CVD). After the outbreak of COVID-19, only PM10 significantly affected the death risk of CVD. In addition, we discovered that PM2.5, PM10, and SO2 significantly impacted the risk of death due to respiratory diseases before and after the outbreak of COVID-19.ConclusionsAir pollutants have different effects on nonaccidental deaths before and after the COVID-19 outbreak. A decrease in air pollutant concentration due to the NPIs for COVID-19 had a significant effect on the reduction of the risk of nonaccidental death.

Technological line for the production of sunflower cake

BACKGROUND: The results of the study conducted to increase the shelf life of sunflower cake by justifying the optimal operating parameters of the ozonizer in the line of the sunflower cake production are presented. Studies of the processing of sunflower cake with an ozone-air mixture at optimal operating parameters, such as its concentration, the duration of its processing and the intensity of the high-frequency field, have been conducted. AIM: Increasing of the long-term storage of protein feed by improving the basic design parameters of the device for its production. METHODS: Resulting from the conducted theoretical research, the technological line for the protein feed production was developed according to the patent for the invention of the Russian Federation No. 2706188. To determine the optimal operating parameters of the device in the sunflower cake production line, which affect its shelf life, the design of experiment theory was used. RESULTS: A regression equation in coded values, characterizing the effect of the concentration of the ozone-air mixture, the duration of the sunflower cake treatment and the intensity of the high-frequency field on the sunflower cake shelf life, is obtained. The analysis of the obtained mathematical model of the processing process is performed. CONCLUSION: Experimental studies of the developed line for the production of sunflower cake with quality control of its treatment with an ozone-air mixture have shown that the sunflower cake shelf life depends on the ozone-air mixture concentration and the duration of treatment of the sunflower cake, as well as on the intensity of the high-frequency field. At the same time, with a decrease in the ozone-air mixture concentration, the duration of treatment of the sunflower cake and the intensity of the high-frequency field during the treatment increase. In the area of low concentration, increased duration up to 120 s and intensity up to 15250 V/m, the shelf life of the cake increases. It is reasonable to process sunflower cake with the ozone-air mixture to increase its shelf life from 3 to 5.45 months according to the GOST 80-96 using the developed line (patent RF 2706188) at a concentration of 23.03 mg/m3, processing time of 134 s and a high-frequency field strength of 17374 V/m.

Effects of gestational age on blood cortisol and prolactin levels during pregnancy in malaria endemic area.

The hormonal shift occurring in pregnant women is crucial for the outcome of pregnancy. We conducted a study in pregnant women living in a malaria endemic area to determine the potential effect of gestational age on the modulation of the endocrine system by cortisol and prolactin production during pregnancy. Primigravidae and multigravidae with a gestational age between 16-20 weeks were included in the study and followed up to delivery and 6-7 weeks thereafter. Venous blood was collected at scheduled visit: Visit 1 (V1; 16-20 weeks of amenorrhea), Visit 2 (V2; 28 ±1 weeks of pregnancy), Visit 3 (V3; 32 ±1 weeks of pregnancy), Visit4 (V4; delivery) and Visit5 (V5; 6-7 weeks after delivery). In addition, a cord blood sample was also collected during labour at delivery. Nulliparous and primiparous/multiparous non-pregnant women were enrolled in the control group. Cortisol and prolactin plasma concentrations were measured using ichroma II and i-chamber apparatus. Light microscopy was used to detect Plasmodium falciparum infections. A linear mixed-effects regression (LMER) model was used to assess the association between the variation of cortisol titres and prolactin levels during the pregnancy and the post-partum. Results showed that cortisol and prolactin levels in the peripheral blood were globally up-regulated during pregnancy. Concentrations of cortisol during follow-up was significantly higher in primigravidae than in multigravidae during the whole pregnancy (p<0.024). Moreover, the level of prolactin which was higher before delivery in primigravidae reversed at delivery and postpartum visit, but the difference was not statistically significant during the follow-up (V1 to V5) (p = 0.60). The cortisol level in peripheral blood at delivery was higher than that in the cord blood, and conversely for prolactin. Cortisol and prolactin levels decreased after delivery, though the level of prolactin was still higher than that at enrolment. An increase of one unit of prolactin was associated with the decrease of the average concentration of cortisol by 0.04 ng/ml (p = 0.009). However, when cortisol increases with one unit, the average concentration of prolactin decreases by 1.16 ng/ml (p = 0.013). These results showed that the up-regulation effects of cortisol and prolactin are related to gestational age. A The downward regulation effect that both hormones have on each other during the pregnancy when each increase to 1 unit (1.0 ng/ml) was also reported.

Effects of fluid properties on coarse particles transport in vertical pipe

The mineral resources in deep-seabed are attracting extensive attention. A numerical simulation of particle transport in a vertical pipe for a deep-sea mining system is conducted using the CFD-DEM method. The effects of fluid density, fluid viscosity and rheological parameters of non-Newtonian fluids on the liquid-solid flow behavior in a vertical pipe are investigated. For Newtonian fluids, increasing the density or viscosity enhances the particles' performance in following the fluid and reduces the slip velocity, but also increases the pressure drop. The efficient lifting of particles can be facilitated by adjusting fluid density and viscosity, while considering factors such as energy consumption. For non-Newtonian fluids, an increase in either the flow behavior index n or the consistency coefficient k results in an increase in the fluid's apparent viscosity. This leads to an increase in the particle suspension capacity and local particle velocity, along with a decrease in local particle concentration.

Bambara groundnut starch-soluble dietary fibre nanocomposite stabilised emulsions: Optimisation of emulsion stability and studies on time-dependent rheological properties

Due to their inherent thermodynamic instability, emulsions require stabilisers to maintain their integrity and prevent destabilisation. The effect of emulsion components (Bambara groundnut starch-soluble dietary fibre nanocomposite (STASOL), orange oil and water) on the rheological and stability properties of STASOL-stabilised emulsions was optimised. A randomised D-optimal exchange mixture design was used to determine the ratio of STASOL, orange oil and water required for a stable emulsion. The stability of these emulsions was evaluated using the initial mean backscattering index (BSAVO), Turbiscan stability index (TSI) and hysteresis loop area (HLA). The BSAVO (%), TSI and HLA of the emulsions ranged from 50.73% (14:30:56 STASOL:oil:water) to 70.47% (20:30:50 STASOL:oil:water), 0.0005 (20:30:50 STASOL:oil:water) to 0.1000 (8:42:50 STASOL:oil:water) and 0.37 Pas-1 (10:32:58 STASOL:oil:water) to 5.69 Pas-1 (20:30:50 STASOL:oil:water), respectively. Emulsions exhibited a direct relationship between STASOL concentration and stability metrics, with the highest stability achieved at 20% STASOL concentration, 30% orange oil and 50% water. An increase in STASOL concentration coupled with a decrease in oil concentration results in a stable emulsion. Numerical optimisation and experimental validation confirmed the effectiveness of the selected formulation, demonstrating STASOL's potential as a natural stabiliser in beverage emulsions and its ability to enhance stability compared to synthetic alternatives.

A rapid colorimetric sensor for the detection of mercury in environmental samples employing 2 aminobenzohydrazide schiff base functionalized silver nanoparticles

Mercury (Hg2+) is an extremely toxic and dangerous element for living organisms. Herein, a simple and selective sensor based on the Schiff base of 2-aminobenzohydrazide with triazole thiazole substituted vanillin (EAHT) functionalized silver nanoparticles (EAHT-AgNPs) is proposed for the detection of Hg2+ in environmental water samples. The chemical reduction method was employed to synthesize EAHT-AgNPs using sodium borohydride as the reducing agent. The synthesized nanoparticles were initially confirmed by UV-visible and FTIR spectroscopy, followed by analysis with a zeta sizer to determine their average size, surface charge and polydispersity index. The atomic force microscopy (AFM) and scanning electron microscopy (SEM) were employed to determine the size and morphology of EAHT-AgNPs. Additionally, the functionalized particles exhibited stability at varying pH values, salinity concentrations and elevated temperature. The addition of Hg2+ altered the yellow color of EAHT-AgNPs to colorless, confirming the complex formation. The analytical response constructed as a decrease in absorbance versus concentration showed linearity (R2 = 0. 991) from 0.1 to 100 µM with a limit of detection of 0.04 µM (40 nM) and limit of quantification of 0.085 µM (85 nM). The sensor was successfully applied for the detection of Hg2+ ions in tap water. In conclusion, Schiff base of 2-aminobenzohydrozide with triazole thiazole substituted vanillin silver nanoparticle-based chemosensor is highly sensitive and selective for the detection of Hg2+ in water samples. The proposed sensor has been applied for mercury detection tap water, future research should explore its applications in more complex samples like industrial wastewater and marine environments. Further, studies may focus on the integrating of the approach into the portable devices such as smartphone for on-site detection of mercury.

The Impact of Methamphetamine on Liver Injury in Iraqi Male Addicts

Methamphetamine (METH) is a powerful stimulant that affects neurochemical processes controlling heart rate, appetite, blood pressure, body temperature, and wakefulness, making it highly susceptible to abuse. Liver enzymes such as ALT, AST, ALP, and GGT are crucial for liver function. Albumin, a protein synthesized by healthy liver cells, serves as an indicator of chronic liver disease. Additionally, hepatocytes produce bile acids, which are essential for the secretion of bile salts into the bile canaliculi. Disruption in this secretion results in the accumulation of bile salts in the canaliculi, leading to intrahepatic cholestasis. METH-induced liver toxicity involves disruptions in hepatic metabolism, oxidative stress, and increased body temperature, affecting cellular processes such as cell division and the cell cycle and potentially accelerating liver cell apoptosis. The study explores the link between liver toxicity and hepatocyte damage in Iraqi males suffering from addiction. This is a case-control study, conducted at Ibn-Rushed Psychiatric Hospital in Baghdad from July 2023 to February 2024, involved 196 males, with addiction durations exceeding 24 months with varying degrees of methamphetamine (METH) addiction. The study included 187 healthy male controls with no history of drug addiction. Participants were aged 18 to 40 years. Diagnosis was confirmed using a drug test screening card administered by a specialist. The study included liver function tests (ALT, AST, ALP, and GGT), total bilirubin, and albumin concentration assessments. Significant differences were observed between the addicts and controls, particularly a marked decrease in serum albumin concentration in the addicted males. The ROC curve classification model at various thresholds demonstrated that liver enzymes, especially ALT, ALP, and GGT, exhibited increased sensitivity to METH addiction. A histopathological examination was conducted on a deceased 38-year-old male who had a six-year history of chronic amphetamine addiction to confirm liver injury and the resulting elevation of liver enzymes. The findings of this study indicate that METH greatly affects liver function, suggested to the importance of following a preventative measures and effective treatment approaches for monitoring METH addiction progress.

Neuroprotective Effects of Curcumin against Chronic Chlorpyrifos- Induced Oxidative Damage in Rat Brain Tissue.

Chlorpyrifos (CPF) is an organophosphate pesticide that inhibits acetylcholinesterase (AChE) activity. Investigations have also focused on its neurotoxicity, which is independent of AChE inhibition. Here, we evaluated the effect of CPF on oxidative indices in the brain tissue and explored the protective effect of curcumin (Cur) against its toxicity. Forty male Wistar rats were divided into five groups, each consisting of eight rats (n = 8) per group. Animals were administrated by oral gavage for 90 days with the following treatments: control (C), CPF, CPF + CUR 25 mg/kg, CPF + CUR50, and CPF + cur 100 received olive oil, CPF, CPF plus 25 mg/kg of CUR, CPF plus 50 mg/kg of CUR, and CPF plus 100 mg/kg of CUR, respectively. After anesthetization, animal brain tissues were obtained for assessment of oxidative stress indices. The concentration of MDA significantly increased in the brains of the CPF group as compared to the control group (p < 0.01). Also, a significant decrease in MDA concentrations was observed in the brains of rats in the CPF + Cur 100 group compared to the CPF group (p < 0.05). A significant decrease was noted in the GSH concentration in the brains of the CPF group compared to the control group (p < 0.05). Treatment with Cur at 100 mg/kg exhibited a significant increase in GSH concentrations in the brains of the CPF-exposed group compared to the CPF group without Cur administration (p < 0.05). The concentration of NO exhibited a significant increase in the brains of the CPF group when compared to the control group (p < 0.05). Also, a significant decrease in NO concentration was observed in the brain tissue of the CPF + Cur 100 group compared to the CPF group (p < 0.05). Our data establish that chronic exposure to CPF induced oxidative stress in brain tissue, which was reversed by CUR administration. Additional experimental and clinical investigations are needed to validate the efficacy of CUR as a potential antidote for CPF poisoning.

Enhanced SO2 and CO2 synergistic capture with reduced NH3 emissions using multi-stage solvent circulation process

NH3-based SO2 and CO2 synergistic capture technology shows promise in reducing the costs associated with current flue gas desulfurization and CO2 capture systems. However, it faces challenges such as NH3 slip and high energy consumption. In this study, we proposed an advanced Multi-Stage Solvent Circulation (MSC) process that incorporates a desulfurization-washing solution circulation, which involved partitioned absorption according to different functions of SO2 capture, CO2 capture, and NH3 emission control. The experimental results demonstrated that using desulfurization solution in place of water for washing reduced the NH3 emissions from the absorber and desorber by 10.6 % and 7.9 %, respectively. Additionally, the recovered NH3 enhanced SO2 capture, resulting in a 61.8 % decrease in SO2 emission concentration. A pilot-plant trial model for SO2 and CO2 synergistic capture was further developed using Aspen Plus. The impact of operational time and parameters on capture efficiency and energy consumption were analyzed. Under typical flue gas conditions, the process achieved SO2 capture efficiency of > 99 %, regeneration energy consumption of 2.42 GJ/t CO2, NH3 emissions of < 5 ppm. This study presents a novel approach for designing a SO2 and CO2 synergistic capture system, which has the potential to facilitate the economic and effective implementation of post-combustion flue gas pollutant control management and carbon emission reduction.

Biogeochemical sulfur transformations in the cohesive and permeable tidal flat sediments of Jade Bay (North Sea)

Intertidal flats are highly productive coastal marine ecosystems which are affected by fast changes in environmental conditions and host dynamic biogeochemical cycles in their sediments. Bioturbation by burrowing organisms and roots of plants strongly affects speciation and cycling of redox-sensitive elements in intertidal sediments. In this work, we have studied the impact of sediment type and vegetation on the cycling of redox-sensitive elements including sulfur, iron, and manganese in sandy and muddy tidal flats sediments in the Jade Bay (North Sea) and adjacent area. The redox speciation of these elements was analyzed in the pore-waters and the total sediment. The isotopic compositions of sulfur species were measured in non-vegetated sediments and in sediments which are inhabited by various plants. In the cohesive sediments, which are not affected by vegetation, a decrease in sulfate concentration, coupled with the presence of relatively high concentrations of hydrogen sulfide in the pore-waters and the presence of sulfide minerals as well the isotopic compositions of sulfur species are consistent with fast rates of sulfate reduction in the sediments. In the cohesive sediments affected by roots of Salicornia stricta and sediments desiccation, a cryptic sulfur cycle, which is characterized by microbial sulfate reduction coupled to fast reoxidation of hydrogen sulfide by Fe(III) (hydr)oxides and, possibly, by oxygen is present. Below the roots penetration depth, speciation of redox-sensitive elements is similar to those in the baren sediments. In the cohesive sediments affected by the roots of Spartina anglica and Triglochin maritima, which have longer roots, a cryptic sulfur cycle was detected in the upper 30 cm of sediments. At the sites that are characterized by permeable surface sediments and alternating permeable and cohesive layers in the deeper sediments, the composition of the sediment has a similar or even more significant impact on the speciation of the redox-sensitive elements than penetration of relatively weak roots of Spartina anglica. These sediments are characterized by the formation of hydrogen sulfide and sulfide oxidation intermediates in the cohesive layers and their diffusion to (and oxidation at) the boundaries between cohesive and permeable sediments. We conclude that in the cohesive sediment, the penetration of roots and desiccation leads to the formation of overall oxidized conditions in the sediments, while in the sediments with alternating layers, permeability may provide a more significant control for speciation of redox-sensitive elements.

The influence of pulsation ventilation on the removal and distribution of gas accumulation areas during gas leakage in industrial plants

A ventilation system with a constant velocity air supply might form airflow stagnant zones in industrial plants, making it challenging to dilute hazardous gas effectively. In this study, a novel ventilation mode called pulsating ventilation, which can potentially dilute the hazardous gas better, was applied in a ventilated room with nozzle air supply. Three different scenarios of gas accumulation were assumed, with the location of gas accumulation situated at the rear, near the floor, and in the corners of the room. Both the distribution of CO2 concentration and the efficiency of reducing the indoor CO2 concentration to the safety threshold were analyzed to evaluate the ventilation performance of pulsating ventilation. The results showed that pulsating ventilation outperformed constant velocity air supply in expeditiously eradicating gas accumulation areas for equivalent total air volumes. When the gas accumulation areas were located at the rear of the room, close to the floor, and in the corner of the room, pulsation ventilation reduced the time for the indoor CO2 concentration to drop to the safety threshold by 36.19%, 27.23%, and 36.25%, respectively. Holding the period constant, an increased amplitude correlated with a swifter decrease in peak pollutant concentration. Except for the case where the gas accumulation areas are close to the floor, when the amplitude is constant, the larger the period, the faster the peak concentration in the gas accumulation areas decreases.

Phototransformation and photoreactivity of MPs-DOM in aqueous environment: Key role of MPs structure decoded by optical and molecular signatures

The dissolved organic matter (DOM) derived from microplastics (MPs-DOM) can be one of the photoactive components in DOM. However, information on the properties and photoreactivity of MPs-DOM during phototransformation is limited. Here, we investigated the properties and photoreactivity of MPs-DOM from polyolefins (MPs-DOM-POs), MPs-DOM derived from benzene-containing polymers (MPs-DOM-BCPs), and Suwannee River natural organic matter (SR-NOM), during a 168-hour phototransformation. After phototransformation, all examined types of DOM exhibit a decrease in concentration and molecular weight. Notably, MPs-DOM-POs display increased aromaticity and saturation, while MPs-DOM-BCPs and SR-NOM show reduced aromaticity and saturation. MPs-DOM-POs present higher steady-state concentrations of •OH but much lower steady-state concentrations of 1O2 than those of MPs-DOM-BCPs. In comparison, MPs-DOM produce more •OH but less 1O2 than SR-NOM. This study proposes that the diversification of aliphatic C─H bonds (arylation and carbonylation) by reactive intermediates (especially •OH) is the main pathway for MPs-DOM-POs phototransformation for the first time. On the other hand, the cleavage on the aromatic carboxylic acids by reactive intermediates (especially 1O2) is the main mechanism for MPs-DOM-BCPs and SR-NOM phototransformation. Our findings provide new insights into the phototransformation and photoreactivity of MPs-DOM and help to understand the potential risks of MPs in aqueous environment.

Variations in air pollution before, during and after the COVID-19 lockdown in Peruvian cities.

The high concentrations of air pollutants in Peru remain a persistent problem, significantly impacting public health. Understanding the extent to which the COVID-19 lockdown affected these contaminants is crucial. To determine variations in NO2, O3, CO, and SO2 concentrations in 10 Peruvian cities before, during, and after lockdown. A comparative ecological study was conducted in urban areas of 10 major Peruvian cities using the Google Earth Engine (GEE) platform. Data on atmospheric pollutant concentrations were extracted from the Sentinel-5P/TROPOMI satellite images for the period between March 16 and June 30, across the years 2019, 2020, 2021, and 2022, for comparative analysis. The Wilcoxon test was used to evaluate changes between the study periods. We included 10 urban cities located across three geographic regions of Peru. Most urban cities experienced a decrease in NO2 concentrations and an increase in O3 and CO levels during the lockdown, while SO2 concentrations remained relatively constant. The lockdown has caused variations in NO2, O3 and CO concentrations. Future studies with accurate data on air pollutant concentrations are needed to ensure targeted and effective interventions.

The health impact of PM2.5 and O3 in Beijing modified by infiltration factors from 2014 to 2022.

PM2.5 and O3 are significant threats to the health of residents and modern residents spend more than 80% of their time indoors, so quantifying indoor exposure of residents has a positive influence on formulating policies and improving health indicators. Analysis of monitoring data shows a consistent decrease in the annual average concentration of outdoor PM2.5 in Beijing from 90.1 to 30.4μg/m3, and the equivalent human exposure concentration also declined from 55.2 to 18.6μg/m3 modified by infiltration factors from 2014 to 2022, while during the peak season, the average value of O3-8h concentration in Beijing has consistently remained between 159.3 and 225.3μg/m3; the equivalent human exposure concentration remained between 64.7 and 92.3μg/m3 modified by infiltration factors from 2014 to 2023. The equivalent exposure concentration is calculated by weighting the concentration of indoor and outdoor pollutants, the proportion of indoor and outdoor activity time of the population, and the permeability coefficient of outdoor pollutants into the room, so as to quantify the actual concentration of pollutants exposed to the human body in a certain time. Previous studies have primarily focused on the impact of annual changes in pollutant concentrations on health estimates, often neglecting indoor concentrations and behavior patterns. This limitation should be addressed. Therefore, this study utilized equivalent human exposure concentration and AirQ + , the authoritative software released by the World Health Organization (WHO), to evaluate quantitatively the impact of PM2.5 and O3 on the health of Beijing residents by combining pollutant concentration, annual population, and mortality of various diseases and other indicators to enhance the credibility of the study. The number of deaths related to PM2.5 has decreased from 28,182 people in 2014 to 10,250 people in 2022 (age ≥ 30). The number of premature deaths in 2022 was only 36.4 percent of that in 2014 and was decreasing by 1992 per year. The number of deaths related to O3 varies between 550 and 3358 people. Lowering PM2.5 and O3 concentrations can effectively reduce natural premature death as well as cardiovascular and respiratory diseases caused by air pollution. The government should persist in enhancing the regulation of PM2.5 and accord significance to the oversight of O3. Concurrently, there is a need to reinforce the cooperative regulation addressing both PM2.5 and O3.

Advances in Room Temperature of Indium Aluminum Nitride InAlN Deposition via Direct Current (DC) Co-Sputtering for Solar Energy Applications

This study presents an innovative method for the synthesis of indium aluminum nitride (InAlN) layers by direct current (DC) co-sputtering at room temperature, with the aim of reducing production costs of optoelectronic devices. Indium and aluminum targets are used, varying the power applied to the aluminum target. The results show that increasing the target power favors the formation of aluminum nitride (AlN), which modifies the chemical composition of the material. The layers obtained present smooth surfaces with a roughness of less than 3 nm, which is beneficial for applications requiring interfaces with low defect density. Regarding the optical properties, it is observed that the optical bandgap varies between 1.8 eV and 2.0 eV, increasing with the target power. Hall effect measurements indicate a decrease in the free carrier concentration and an increase in the resistivity with increasing power. This approach allows for the synthesis of InAlN with properties suitable for optoelectronic applications, solar cells, photocatalysis, and photoelectrocatalysis at low cost.