Total Content Research Articles

The initial results of MRI-TRUS fusion prostate biopsy in high volume tertiary center.

Multiparametric magnetic resonance imaging (mpMRI) is a prerequisite for targeted prostate biopsy. The aim of our study was to evaluate the performance and learning curve of the mpMRI-transrectal ultrasound (TRUS) software image fusion (MRI-TRUS fusion) biopsy (BX) process in the first year after its introduction in our urology department. MRI-TRUS fusion BX was performed in 293 patients with at least one Prostate Imaging-Reporting and Data System (PIRADS) ≥3 lesion. The proportion of patients and lesions with positive histopathologic result for prostate cancer (PCa) was analyzed. The learning curve for MRI-TRUS fusion BX was assessed at institutional and individual level. Positive BX lesions were further analyzed by PIRADS and Gleason scores. The proportion of patients with positive histopathologic results for targeted BX, systematic BX, and combined BX was 53.9%, 47.9%, and 63.5%, respectively. The chi-square test for the proportion of PCa positive patients showed no significant difference between the time-based patient groups at the institutional level and no significant difference between individual urologists. PIRADS score (p < 0.001), total PSA concentration (p = 0.05), prostate volume (p < 0.001) and number of cores per lesion (p = 0.034) were significant predictors of a positive histopathologic result in a lesion-based analysis. Clinically significant PCa (csPCa) was confirmed in 34.7% of the 412 BX lesions and 76.4% of the 187 positive PCa lesions. MRI-TRUS fusion targeted BX significantly improves the overall rate of PCa detection compared with systematic BX alone. No steep learning curve was observed in our urologists. The proportion of lesions with clinically insignificant PCa was low, limiting overdiagnosis of PCa.

Yield and Quality of Snap Bean (Phaseolus vulgaris L.) Cultivars from Successive Harvests in Spring and Fall Production Seasons in Oklahoma

Numerous studies have evaluated snap bean pod yield and quality at different pod maturities, but only a few have evaluated yield and pod quality across different seasons within the same year or for pods harvested at the same relative maturity successively from the same plants. Hence, the aim of this study was to determine if snap bean yield or pod sugar accumulation differed for pods at the same relative stage of maturity from plants harvested multiple times in spring and fall planting seasons in north central Oklahoma. Nine snap bean cultivars (seven green-podded and two yellow-podded) were field-grown in Spring and Fall 2022 and 2023. Pods were harvested weekly for 3 weeks from the same plants and at the same relative pod development stage. Pod yield and sugar concentration were measured. The total pod yield pooled across seasons and years of ‘Sybaris’ was lower (approximately 4100 kg⋅ha−1) than that of six of the other cultivars, which yielded between 7000 to 8600 kg⋅ha−1. In spring, pod yield increased from 900 to 1300 kg⋅ha−1 in the first harvest to 3500 to 3700 kg⋅ha−1 by the last harvest. In Fall 2022, the yield decreased from 1900 kg⋅ha−1 in the first harvest to 690 kg⋅ha−1 by the last harvest, whereas in Fall 2023 the pod yield remained steady at 2600 to 3000 kg⋅ha−1 at each weekly harvest. The Fall 2022 decrease in yield was likely caused by low temperatures during pod development and a freeze that shortened the harvest season. From the first to the last harvest, the total pod sugar concentration decreased from 145.5 to 107.2 mg⋅g−1, glucose decreased from 48.4 to 33.0 mg⋅g−1, and fructose decreased from 90.7 to 52.0 mg⋅g−1. However, the sucrose concentration increased from 9.2 to 21.9 mg⋅g−1. This decrease in the total and monomeric sugar concentrations, coupled with a disproportionally smaller increase in sucrose, is typical for overly mature snap bean pods, which are considered less desirable because of lower sweetness. Snap bean pods harvested later in the growing season in a successive harvest system at the same relative stage of maturity as earlier harvested pods had sugar concentrations resembling those of overly mature pods, indicating that snap bean plant age may influence the pod sugar concentration.

Effects of aging of polyethylene microplastics and polystyrene nanoplastics on antibiotic resistance gene transfer during primary sludge fermentation

The increasing presence of nano and microplastics (NPs/MPs) in wastewater treatment plants and their inevitable accumulation in the sludge has raised serious concerns in recent years. This study investigated the effects of pristine and aged polyethylene microplastics (PEMPs), polystyrene nanoplastics (PsNPs), and their mixtures on the primary sludge fermentation process. Pristine MPs/NPs (150 μg/L and 2 g/L for PsNPs and PEMPs, respectively) underwent two weeks of weathering in the presence of humic and alginic acids. The results from a batch fermentation experiment (15 days, pH 10) revealed that the exposure to aged PEMPs/PsNPs experienced greater VFA production than pristine samples. Notably, the aged PEMPs/PsNPs mixture showed a 23.12% increase in VFA production over the pristine mixture. The relative abundance and total concentration of antibiotic resistance genes (ARGs) increased in all PEMPs/PsNPs batches compared to the control, with the most significant rise in total ARGs observed in the aged PEMPs sample. Aged PEMPs exhibited a 26.22-fold increase in tetA genes, while aged mix samples showed a 19.68-fold increase in tetM genes compared to their pristine counterparts. Both pristine and aged PEMPs/PsNPs, particularly the aged PEMPs adversely affected the microbial communities at the genus level and altered the microbial structure. Microbial richness and diversity were enhanced in samples exposed to pristine PEMPs/PsNPs and aged PsNPs but decreased in aged PEMPs and in the aged mixture group, suggesting a negative impact of aged polyethylene microplastics on microbial communities. Correlation analysis suggested that phyla Planctomycetes, Proteobacteria, and TM7 are potential hosts of ARGs. These findings manifest the substantial effects of aged nano/microplastics compared to their pristine forms, emphasizing the complex interplay between various forms of PEMPs/PsNPs and microbial dynamics in sludge fermentation processes.

Decoding historical and emerging environmental concerns of C6−36 chlorinated paraffins: Insights from marine sediment cores in the Pearl River Estuary

Chlorinated paraffins (CPs) readily deposit in sediments upon entering estuaries and adjacent seas. Time-series investigations are indispensable for the long-term monitoring of historical releases and identifying CPs of emerging concerns in the marine environment. In this study, short-, medium-, and long-chain CPs (SCCPs, MCCPs, and LCCPs) were investigated using time-of-flight high-resolution mass spectrometry (ToF-HRMS) in sediment cores, dated between the 1920s and the 2010s sampled from Hong Kong waters and Lingdingyang of the Pearl River Estuary (PRE), South China. Levels of SCCPs remained steady since the 1980s, while increasing trends of MCCPs and LCCPs were observed, indicating a market supply shift from SCCPs to MCCPs and LCCPs, potentially influenced by global restrictions. This is the first study to report C18−31 CPs in Chinese marine sediments. C>20 very long-chain CPs (C>20 vLCCPs) subcategorized from LCCPs semi-quantified via ToF-HRMS positively correlated with those of other CP categories, implying their synchronized release in the investigated regions. C>20 vLCCPs, contributing an average of 27% of total CP concentrations in two cores, were found at higher levels than LCCPs (7%). Hence, the risk of C>20 vLCCP contamination should not be ignored. By highlighting the temporal variations in the world’s largest producer and consumer of CPs, the present study augments the database of the continuous deposition of SCCPs and MCCPs in marine sediments in the PRE and highlights the unrecognized risks of LCCP contaminations.

Purification Effect of Fish–Algae Coupling on Nitrogen and Phosphorus in Shrimp Aquaculture Effluent

As the scale of shrimp aquaculture continues to expand, the environmental impacts of shrimp effluents have become increasingly severe. The purification of aquaculture effluents can no longer be overlooked. Effectively reducing the discharge of aquaculture wastewater and mitigating its potential pollution risks to the surrounding aquatic ecological environment are key issues that need to be addressed to promote the industry’s development towards a greener, more environmentally friendly, and sustainable path. This study explored the purification effect of the integration of tilapia and Spirulina on tail water from a zero-water-exchange aquaculture of whiteleg shrimp (Litopenaeus vannamei) in seawater, with the aim of assessing the growth performance of tilapia and the efficacy of the fish–algae integration in purifying tail water from the perspective of tail water resource utilisation. The study found that the removal rates of the biofloc sedimentation volume and total suspended particle concentration in the fish–algae group were 42.6% and 29.6%, respectively. The removal rates of phosphate and total phosphorus in the fish–algae group were 26.3% and 20.8%, respectively. Research indicates that tilapia effectively removes suspended organic matter from water. Introducing Spirulina into this water body aids in the removal of soluble nitrogen and phosphorus from the effluent, and tilapia exhibit a favourable feeding response to Spirulina.

Protective effect of Glycyrrhizic Acid against diclofenac-induced renal damage in male albino rats

Acute renal injury is a serious condition of severe damage to the kidney tissue resulting from various causes. Some medicinal plants have been used to treat certain renal injury. The purpose of the current investigation was to determine the protective effect of Glycyrrhizic acid (GA) on kidney function in rat models with induced kidney damage by Diclofenac sodium (Voltarene®, 50 mg coated tablets). Glycyrrhizic acid was given at doses of 200 and 400 mg/kg/day orally for 30 days. Its protective effect was evaluated by renal function tests . The result showed significant decreased the elevation of urea , serum creatinine and uric acid. Also, The result show significant decrease in total cholesterol, triglyceride concentration and low-density lipoprotein, and a significant increase in high-density lipoprotein concentration. Therefore, GA can be used for the prevention and treatment of renal damage and some kidney and liver disorders.

Optimization of the Disinfection Process in Potabilization Systems in Cuenca Alto Atoyac, Mexico

Access to drinking water in Cuenca Alto Atoyac (CAA), serving over 3.5 million people, is challenged by contamination and inadequate disinfection processes. This study investigates the use of oxidation–reduction potential (ORP) as a tool to optimize disinfection in CAA’s water systems. The research was conducted in three stages: an initial pilot phase with 10 sampled sources, expanding to 14 supply sources in the experimental phase, followed by analyses defining optimal chlorine dosing and contact times across two distinct hydrogeological zones. Principal component analysis (PCA) identified key factors, explaining 53.52% of water quality variability, while ORP measurements revealed significant differences in water quality among sources, with “Ameca” and “Pozo #2 Santa María Atlihuetzían” representing the extremes. Adjusted chlorine doses and contact times were tailored to local conditions, achieving target ranges and ensuring improved microbial control. In the final stage, significant correlations were established between ORP levels, chlorine doses, and total coliform concentration, supporting the effectiveness of ORP in guiding disinfection processes. Overall, chlorine doses of 0.3–1.5 mg/L with contact times around 15 min yielded ORP values (594–687 mV) optimal for CAA water safety.

In vitro assessments of antioxidant, antimicrobial, cytotoxicity and anti-inflammatory characteristics of flavonoid fractions from flavedo and albedo orange peel as novel food additives

Natural food additives have gained popularity in recent years among consumers and the food service sector. Flavonoids are beneficial to people's health and can be found in many different types of fruits and vegetables. So, this work's purpose is to isolate and identify the flavonoid fractions isolated from the flavedo and albedo orange peel and examine their biological properties as potential novel food additives. Total phenolic and total flavonoid contents of water, ethanolic, and ethyl acetate extracts were determined. The isolated flavonoid fractions were identified, quantified, and classified using HPLC following isolation using column chromatography. Evaluations were conducted on the antimicrobial, anticancer, and anti-inflammatory characteristics of flavonoid fractions. The findings indicated that, compared to the albedo layer, the flavedo layer had higher total phenolic and total flavonoid concentrations. That ethyl acetate solvent was the most suitable for extracting flavonoids from orange peels. According to the HPLC analysis, the isolated flavonoid fractions contain a variety of flavonoid subclasses, including flavones, flavanones, and flavonols. The extracted flavonoid fractions showed efficacy against all tested strains of pathogens, exerted the largest cytotoxic effect, and displayed the highest anti-inflammatory capabilities. In conclusion, the flavedo and albedo orange peels have significant nutritional value that humans can consume, along with the potential for their use as novel natural food additives.

Stable spatial patterns of concentrations of antibiotic resistant bacteria in irrigation water

Irrigation waters serve as vectors for the spread of antibiotic-resistant bacteria which presents a worldwide health concern. Determining the concentrations of those bacteria in waters used for irrigation is therefore an important monitoring target. The objective of this work was to determine the existence of persistent spatial patterns in antibiotic-resistant bacteria in an irrigation waterbody and compare the patterns with patterns of water quality parameters. Escherichia coli, total coliforms, and total heterotrophic bacteria concentrations were measured in water samples collected from 20 sites across an irrigation waterbody on nine sampling dates. The Empirical Orthogonal Function (EOF) analysis was used to detect persistent spatial patterns of tetracycline- and cefotaxime-resistant bacteria as well as water quality parameters. The average concentrations of both generic and antibiotic-resistant bacteria were an order of magnitude higher in bank sampling sites than interior sites. From the EOF analysis results, sampling locations were identified which could provide the best estimates of the average concentrations for each bacterial group. Patterns in temperature (rs = -0.638 to -0.749), dissolved oxygen (rs = -0.173 to -0.675), and pH (rs = -0.483 to -0.770) showed the strongest negative correlations with patterns in bacteria concentrations while all other water quality patterns tended to be positively correlated. Results of this work show that the EOF analysis can be a powerful tool in the design of effective monitoring programs which assess antibiotic resistance in irrigation waters by identifying locations which are closest to the spatiotemporal average.

PH-sensitive intelligent packaging films from Kodo millet (Paspalum scrobiculatum) starch and gum tragacanth incorporated with beetroot peel extract for monitoring shrimp freshness

This study aims to develop intelligent pH-sensitive food packaging films based on kodo millet starch (KMS), gum tragacanth (GT), and zinc oxide nanoparticles (ZNP) incorporated with betalain-rich beetroot (Beta vulgaris L.) peel extract (BPE). The physical, mechanical, optical, microstructural, thermal, barrier, and functional properties of films with different BPE concentrations (50, 100, and 200 % of dry matter weight) were studied. The results proved betalain to be the major component in the BPE, which showed significant color change under alkaline conditions. Field emission scanning electron microscopy demonstrated good compatibility among the film constituents. Fourier transform infrared spectroscopy suggested hydrogen bonding interactions between the betalain-BPE and KMS/GT/ZNP-based film matrix. Incorporating the extract at different concentrations enhanced the ultraviolet-visible light barrier, antioxidant properties, and antimicrobial properties. The betalain-rich films showed color variation from pink in an acidic medium to yellow in an alkaline medium. The film with a 200 % concentration of BPE represented the highest color change when exposed to ammonia compared to other films. During the freshness indicator study of shrimp, the total volatile basic nitrogen concentration increased. The film with a 200 % concentration of betalain extract showed visible color changes from pink to pale yellow. Overall, our results suggest that the film containing a 200 % extract concentration can be used as an active pH-responsive packaging in the food industry.

Proteostasis collapse in rat’s lung tissue as one of the effects of European adder (Vipera berus subsp. berus and Vipera berus subsp. nikolskii) envenomation

Abstract Snakebites and their consequences are a growing concern around the globe. The mixture of enzymes, present in snake venom is a great challenge for a snakebite victim’s body. European adder (Vipera berus) is considered as not very harmful snake due to the mild clinical symptoms of envenomation and rare cases of cardiovascular or pulmonary failure. Nevertheless, at the molecular level, many details of V. berus bite (including proteostasis instability) remain unclear. This work was aimed to determine the effect of Eastern Europe typical adder species Vipera berus berus and Vipera berus nikolskii envenomation on the protein homeostasis of rat’s lung tissue. The decrease in total protein concentration, significant redistribution of main protein fractions (including proteolytically active), rise in middle-mass molecules and low molecular weight peptide concentration have been observed during V. b. berus and V. b. nikolskii envenomation, strongly indicating the proteostasis collapse and endogenous intoxication in lung tissue as an effect of European adder snakebite. Moreover, according to the results of experiments, the effect of V. b. nikolskii venom is more harmful to lung tissue protein homeostasis, comparing to V. b. berus, suggesting that the former may represent a greater danger to people. The results of this study may find applications in antivenom development and could be taken into consideration for proper snakebite treatment selection in order to avoid proteome complications in patients.

Machine learning-based identification of critical factors for cadmium accumulation in rice grains.

The aggregation of Cadmium (Cd) in rice grains is a significant threat to human healthy. The complexity of the soil-rice system, with its numerous influencing parameters, highlights the need to identify the crucial factors responsible for Cd aggregation. This study uses machine learning (ML) modeling to predict Cd aggregation in rice grains and identify the influencing factors. Data from 474 data points from 77 published works were analyzed, and eight ML models were established using different algorithms. The input variables were total soil Cd concentration (TS Cd) and extractable Cd concentration (Ex-Cd), while rice Cd concentration (Cdrice) was the output variable. Among the models, the Extremely Randomized Trees (ERT) model performed the best (TS Cd: R2 = 0.825; Ex-Cd: R2 = 0.792), followed by Random Forest (TS Cd: R2 = 0.721; Ex-Cd: R2 = 0.719). The ERT feature importance ranking analysis revealed that the essential factors responsible for Cd aggregation are cation exchange capacity (CEC), TS Cd, Water Management Model (WMM), and pH for total soil Cd as input variables. For extractable Cd as an input variable, the vital factors are CEC, Ex-Cd, pH, and WMM. The study highlights the importance of the Water Management Model and its impact on Cd concentration in rice grains, which has been overlooked in previous research.Please check and confirm that the authors and their respective affiliations have been correctly identified and amend if necessary.The authors and their respective affiliations are correct.Author details: Kindly check and confirm whether the corresponding author is correctly identified.It is correct.

Reference intervals for equine fecal calprotectin and calprotectin:protein ratio and preliminary clinical evaluation in horses with colic and colitis.

To establish the reference interval (RI) of fecal calprotectin (fCP) and fCP:protein ratio in the feces of healthy horses and demonstrate preliminary clinical utility for the quantification of intestinal inflammation. Feces were collected from healthy horses (n = 103) and horses with colic (n = 15) or colitis (n = 13). Feces were suspended in buffer to create fecal supernatant. Fecal calprotectin concentration was determined by ELISA, fecal total protein concentration was determined by bicinchoninic acid assay, and the fCP:protein ratio was calculated. Reference intervals for fCP and fCP:protein ratio were calculated from healthy horses. Descriptive and inferential statistics were performed to evaluate associations between fCP concentration and fCP:protein ratio with group and other clinical features. The study period was from September 20, 2023, through April 20, 2024. The RI for fCP was 0.056 to 0.278 μg/mL; 4 of 13 colitis cases had fCP above the RI. The RI for fCP:protein was 6.6 X 10-6 to 4.9 X 10-5; 5 of 13 colitis cases and 2 of 15 colic cases had fCP:protein above the RI. Horses with colitis had significantly greater fCP (median [quartile 1, quartile 3], 0.234 [0.194, 0.279] μg/mL) than healthy horses (0.196 [0.138, 0.220] μg/mL) or colic cases (0.189 [0.164, 0.215] μg/mL). There was a greater difference in fCP:protein ratio between colitis cases (4.31 X 10-5 [3.19 X 10-5, 6.23 X 10-5]) and both healthy horses (2.19 X 10-5 [1.58 X 10-5, 2.88 X 10-5]) and colic cases (1.52 X 10-5 [1.22 X 10-5, 3.56 X 10-5]). Both fCP and fCP:protein ratio were increased in horses in colitis; additional work is needed to establish clinical utility. There are few reliable diagnostic modalities for inflammation of the equine large colon. With additional development of a clinically applicable test and validation in larger population, fecal calprotectin may facilitate noninvasive quantification of intestinal inflammation in horses.

Alternate Sampling Matrices for Therapeutic Drug Monitoring of Immunosuppressants.

Immunosuppressant (IS) therapeutic drug monitoring (TDM) relies on measuring mostly pharmacologically inactive erythrocyte-bound and/or plasma protein-bound drug levels. Variations in hematocrit and plasma protein levels complicate interpretation of blood calcineurin inhibitor (CNI) and inhibitors of themolecular target of rapamycin (mTORi) concentrations. Variable binding of mycophenolic acid (MPA) to albumin similarly complicates its TDM in plasma. A different matrix may improve IS concentration-response relationships and better reflect exposures at sites of action. This review explores the evidence for IS TDM using peripheral blood mononuclear cell (PBMC), graft tissue, and total or unbound plasma concentrations. Tandem mass spectrometry provides the sensitivity for assessing these matrices. But several challenges must be addressed, including minimizing hemolysis during blood collection, preventing IS efflux during PBMC preparation, and determining the need for further purification of the PBMC fraction. Assessing and reducing nonspecific binding during separation of unbound IS are also necessary, especially for lipophilic CNIs/mTORi. Although TDM using PBMC or unbound plasma concentrations may not be feasible due to increased costs, plasma CNI/mTORi levels may be more easily integrated into routine TDM. However, no validated TDM targets currently exist, and published models to adjust blood CNI/mTORi concentrations for hematocrit or to predict PBMC, and total and unbound plasma IS concentrations have yet to be validated in terms of measured concentrations or prediction of clinical outcomes. Even if CNI/mTORi measurements in novel matrices do not become routine, they may help refine pharmacokinetic-pharmacodynamic relationships and improve mathematical models for TDM using whole blood. Notably, there is evidence to support measuring unbound MPA in patients with severe renal dysfunction, hypoalbuminemia, and hyperbilirubinemia, with some proposed TDM targets.

Near-infrared diffuse optical characterization of human thyroid using ultrasound-guided hybrid time-domain and diffuse correlation spectroscopies

Thyroid vascularization and hemodynamics become altered in thyroid pathologies and could thus inform diagnostics, therapy planning, and follow-up. However, the current non-invasive monitoring methods available in clinics lack the necessary sensitivity and/or are impractical for large-scale deployment. As a step towards proposing a new modality, we applied the first platform, to our knowledge, designed to do simultaneous measurements of neck anatomy and thyroid microvascular hemodynamics and metabolism in a single probe placement, integrating state-of-the-art near-infrared spectroscopy techniques and clinical ultrasound. A rich dataset was formed with sixty-five subjects (forty-eight females), including eighteen healthy volunteers and forty-seven patients with thyroid nodules, characterizing thyroid tissue and the effects of demographic and anatomical variables while preserving the standard clinical workflow. We have found marked reductions with age and body mass index in thyroid total hemoglobin concentration (THC), tissue oxygen saturation (StO2), and blood flow index (BFi), among others. Patients showed lower THC and BFi than healthy subjects, and the limited sample of malignant nodules showed a higher StO2 than the benign. These findings support the need for personalized clinical approaches.

First Evidence of Cotinine in Canine Semen Reveals Tobacco Smoke Exposure

Tobacco smoke has numerous adverse effects on both human and animal health, including impaired reproductive function. Recent research has explored environmental exposure in dogs, investigating various biological matrices. However, no data are currently available on the presence of cotinine, a nicotine metabolite, in the canine ejaculate. This study aimed to evaluate the detectability of cotinine in the semen of dogs living with smoking owners. Additionally, seminal cotinine concentrations were correlated with those in serum and hair. To further examine the potential impact of smoking on canine fertility, the relationships between seminal cotinine, total sperm concentration, and antioxidant activity in plasma and semen were analyzed in exposed and non-exposed dogs. This study is the first to demonstrate the presence of cotinine in canine ejaculate and its correlation with blood and hair concentrations. While the potential toxic effect of cotinine on seminal parameters and male fertility in dogs requires further investigation, it is crucial to raise awareness among pet owners about the risks associated with domestic smoking for their animals.

Identification of priority factors for risk control of trace toxic elements in surface resuspended dust of university campuses

The surface resuspended dust (SRD) that accumulates trace toxic elements (TTEs) can be suspended in the atmosphere and can be transported to other areas, such as campuses, through airflow. The risks and sources of TTEs in university campus SRD have not been thoroughly explored, especially the priority factors for TTEs pollution and risk control in the SRD. Taking Xi’an as a case, this study quantitatively apportioned the sources of TTEs in the SRD of university campuses using positive matrix factorization method, evaluated the ecological and health risks of the specific-source TTEs in the SRD using Monte Carlo simulation method, and determined the priority factors for risk control of TTEs in the SRD. We found that the pollution of Zn, Pb, and Cu in the SRD was severe, with significantly high to very high enrichment levels. The comprehensive pollution of TTEs in the SRD was high to extremely high levels, with Pb and Zn as the main contributors. The four sources of TTEs identified in the SRD were traffic exhaust, traffic non-exhaust, mixed, and natural sources, accounting for 19.1%, 43.3%, 11.2%, and 26.3% of the total TTE concentrations, respectively. The ecological risk of TTEs was quite serious, mainly caused by traffic exhaust Pb. TTEs in the SRD had a certain cancer risk to college students, mainly contributed by traffic exhaust. Traffic exhaust source is the main factor that needs to be controlled.

TAILORING THE TRIBO-MECHANICAL AND CORROSION BEHAVIOR OF REVERSE PULSE DEPOSITED Ni-Co-P COATING THROUGH COBALT CONTENT MODULATION

Abstract This study explores the influence of cobalt content on the tribo-mechanical and corrosion properties of Ni-Co-P coatings deposited through reverse pulse electroplating. The ratio of Co salt concentration to the total Ni and Co salt concentration was varied in the electrolyte to achieve different Co levels within relatively low cobalt (≤36 wt.%) regime. X-ray diffraction revealed crystallite sizes of 1-3 nm in the deposited layers suggesting a mixture of amorphous and nanocrystalline structure. Critical loads in scratch adhesion tests are found to be in between 10.5 N and 15.1 N implying adequate adhesive bonding between the deposits and the substrates. Microhardness and pin-on-disc tribo- test results demonstrate a positive correlation between Co content and both hardness and wear resistance of the coatings. However, incorporating small amounts of Co (≤6.2 wt.%) exhibited minimal impact on these properties. Interestingly, corrosion resistance in saline medium peaked at the second-highest Co level (26.2 wt.% of Co), followed by a decrease with further increase of Co. These findings indicate an optimal Co concentration for achieving a balance between wear resistance and corrosion protection in Ni-Co-P coatings.

Features of particle-phase PAHs from traffic emissions using tunnel measurement and urban roadside observation in China

Vehicle emissions are recognized as a primary source of particle-phase polycyclic aromatic hydrocarbons (PAHs), significant contributors to the hazardous properties of PM2.5. This study investigates the profiles of PAHs through measurements conducted in a tunnel and an urban roadside environment in 2020. We quantified real-world vehicle emission factors for mixed fleets in the Zhongshu tunnel in Guizhou, southwest China, and found that the total PAHs had an emission factor of 8.15 μg veh-1km-1, with higher factors observed for high-ring PAHs. Additionally, we analyzed concentrations of 15 PAHs at a roadside environment in Hefei, southern China, with an average concentration of 23.81 ng/m3. PAHs with 4, 5, and 6 rings comprised 80% of total PAHs at the roadside and 87% in the tunnel. Gasoline emissions were the predominant source in both the tunnel and roadside environments, supplemented by non-tailpipe emissions, catering, domestic cooking, and asphalt from road surfaces. Notably, while the total toxicity equivalent concentration of Benzo[a]pyrene (BaP) significantly exceeded the World Health Organization (WHO) guidelines of 1 ng/m3, the presence of additional compounds such as Dibenzo[a,h]anthracene (DahA) markedly increased the toxicological impact of PM2.5 from vehicle emissions. Therefore, it is essential to implement targeted pollution control strategies in central urban areas that address not only the overall concentration of PAHs but also their specific toxic contributions Continuous monitoring and assessment of PAHs in the urban environment are indispensable for effectively reducing their health impacts.

Management implications following the reconstruction of the small and shallow Lake Mustijärv (Estonia)

Lake Mustijärv was reconstructed by sediment removal following an almost complete siltation. Here we evaluate challenges and opportunities for the management of the lake. We focused on the stream discharging to the lake (i.e., external loading), sediment retention in accumulation basins (i.e., internal processes) as well as the ecosystem-level response to stressors based on biological variables (phyto- and zooplankton, macrophytes, fishes and zoobenthos). Urban and agricultural inputs elevated ammonium and total phosphorus concentrations in the lake, challenging lake reconstruction efforts. Sediment transport highly increased the risk of faster filling of the lake, associated with upstream streambed excavation. Sediments trapped at the accumulation basins release nutrients that enhance eutrophication. We, however, observed a rapid recovery in fish, macrophytes, and zoobenthos, despite the significant disturbances. Lake Mustijärv is in eutrophic condition, reflected by phytoplankton (Pseudanabaena, Closteriopsis dominance) and zooplankton (Keratella, Polyarthra dominance) composition. To improve lake water quality will require controlling external nutrient inputs, underlining the importance of better coordinated activities between the local (lake restoration) and regional (catchment use) scales.