Search Results (1,627)

Biothiols, including cysteine (Cys), homocysteine (Hcy), and glutathione (GSH), are crucial for physiological regulation and their imbalance poses severe health risks. Herein, we developed a pH-responsive liquid crystal (LC)-based sensing platform for detection of biothiols by doping 4-n-pentylbiphenyl-4-carboxylic acid (PBA) into 4-n-pentyl-4-cyanobiphenyl (5CB). Urease catalyzed urea hydrolysis to produce OH⁻, triggering the deprotonation of PBA, thereby inducing a vertical alignment of LC molecules at the interface corresponding to dark optical appearances. Heavy metal ions (e.g., Hg²⁺) could inhibit urease activity, under which condition LC presents bright optical images and LC molecules maintain a state of tilted arrangement. However, biothiols competitively bind to Hg²⁺, the activity of urease is maintained which enables the occurrence of urea hydrolysis. This case triggers LC molecules to align in a vertical orientation, resulting in bright optical images. This pH-driven reorientation of LCs provides a visual readout (bright-to-dark transition) correlated with biothiol concentration. The detection limits of Cys/Hcy and GSH for the PBA-doped LC platform are 0.1 μM and 0.5 μM, respectively. Overall, this study provides a simple, label-free and low-cost strategy that has a broad application prospect for the detection of biothiols. Full article

HgCdSe has recently been proposed as a potential alternative material to HgCdTe for fabricating high-performance infrared detectors. This work presents a study on the growth of high-crystalline-quality HgCdSe materials on GaSb (211)B substrates via molecular beam epitaxy and demonstration of the first prototype HgCdSe-based mid-wave infrared detectors. By optimizing the MBE growth parameters, and especially the thermal cleaning process of the GaSb substrate surface prior to epitaxial growth, high-quality HgCdSe material was achieved with a record XRD full width at half maximum of ~65 arcsec. At a temperature of 77 K, the mid-wave infrared HgCdSe n-type material demonstrated a minority carrier lifetime of ~1.19 µs, background electron concentration of ~2.2 × 10¹⁷ cm⁻³, and electron mobility of ~1.6 × 10⁴ cm²/Vs. The fabricated mid-wave infrared HgCdSe photoconductor presented a cut-off wavelength of 4.2 µm, a peak responsivity of ~40 V/W, and a peak detectivity of ~1.2 × 10⁹ cmHz^1/2/W at 77 K. Due to the relatively high background electron concentration, the detector performance is lower than that of state-of-the-art low-doped HgCdTe counterparts. However, these preliminary results indicate the great potential of HgCdSe materials for achieving next-generation IR detectors on large-area substrates with features of lower cost and larger array format size. Full article

Proper joint function has a significant impact on people’s quality of life. Joints are the point of connection between two or more bones and consist of at least three elements: joint surfaces, the joint capsule, and the joint cavity. Joint diseases are a serious social problem. Risk factors for the development of these diseases include overweight and obesity, gender, and intestinal microbiome disorders. Another factor that is considered to influence joint diseases is trace elements. Under normal conditions, elements such as iron (Fe), copper (Cu), cobalt (Co), iodine (I), manganese (Mn), zinc (Zn), silver (Ag), cadmium (Cd), mercury (Hg), lead (Pb), nickel (Ni) selenium (Se), boron (B), and silicon (Si) are part of enzymes involved in reactions that determine the proper functioning of cells, regulate redox metabolism, and determine the maturation of cells that build joint components. However, when the normal concentration of the above-mentioned elements is disturbed and toxic elements are present, dangerous joint diseases can develop. In this article, we focus on the role of trace elements in joint function. We describe the molecular mechanisms that explain their interaction with chondrocytes, osteocytes, osteoblasts, osteoclasts, and synoviocytes, as well as their proliferation, apoptosis, and extracellular matrix synthesis. We also focus on the role of these trace elements in the pathogenesis of joint diseases: rheumatoid arthritis (RA), osteoarthritis (OA), psoriatic arthritis (PsA), ankylosing spondylitis (AS), and systemic lupus erythematosus (SLE). We describe the roles of increased or decreased concentrations of individual elements in the pathogenesis and development of joint diseases and their impact on inflammation and disease progression, referring to molecular mechanisms. We also discuss their potential application in the treatment of joint diseases. Full article

Heavy metal pollution from human activities is an increasing environmental concern. This study investigates the concentrations of Cu, Pb, Zn, Cd, Hg, and As in the coastal seawater offshore of Beihai, Guangxi, in April 2021, and explores their relationships with dissolved inorganic nitrogen, phosphate, and salinity. Our results reveal higher heavy metal concentrations in the northern nearshore waters and lower levels in southern offshore areas, with surface waters generally exhibiting greater enrichment than bottom waters. Surface concentrations show a decreasing trend from the northeast to the southwest, likely influenced by prevailing northeast monsoon winds. While bottom water concentrations decline from the northwest to the southeast, which indicates the influence of riverine runoff, particularly from the Qinzhou Bay estuary. Heavy metal levels in southern Beihai waters are comparable to those in the Beibu Gulf, except for Hg and Zn, which are significantly higher in the water of the Beibu Gulf. Notably, heavy metal concentrations in both Beihai and Beibu Gulf remain considerably lower than those observed in the coastal waters of Guangdong. Overall, Beihai’s coastal seawater meets China’s Class I quality standards. Nonetheless, continued monitoring is essential, especially of the potential ecological impacts of Hg and Zn on marine life. Full article

The high pH and heavy metal leaching of argon oxygen decarburization (AOD) slag limit its application in agriculture. Slag carbonation can aid in decreasing slag alkalinity and inhibit heavy metal release; the environmental safety of utilizing carbonated AOD slag (CAS) as a fertilizer remains a topic of significant debate, however. In this work, pakchoi (Brassica chinensis L.) was planted in CAS-fertilized soil to investigate the accumulation and migration behavior of heavy metals in the soil–plant system and perform an associated risk assessment. Our results demonstrated that CAS addition increases Ca, Si, and Cr concentrations but decreases Mg and Fe concentrations in soil leachates. Low rates (0.25–1%) of CAS fertilization facilitate the growth of pakchoi, resulting in the absence of soil contamination and posing no threat to human health. At the optimal slag addition rate of 0.25%, the pakchoi leaf biomass, stem biomass, leaf area, and seedling height increased by 34.2%, 17.2%, 26.3%, and 8.7%, respectively. The accumulation of heavy metals results in diverging characteristics in pakchoi. Cr primarily accumulates in the roots; in comparison, Pb, Cd, Ni, and Hg preferentially accumulate in the leaves. The migration rate of the investigated heavy metals from the soil to pakchoi follows the order of Cr > Cd > Hg > Ni > Pb; in comparison, that from the roots to the leaves follows the order Cd > Ni > Hg > Cr > Pb. Appropriate utilization of CAS as a mineral fertilizer can aid in improving pakchoi yield, achieving sustainable economic benefits, and preventing environmental pollution. Full article

Background/Objectives: The novel compound 221s (2,9), derived from danshensu and ACEI-active proline, exhibits antihypertensive effects (50/35 mmHg SBP/DBP reduction in SHRs) with potential cough mitigation. However, its excretion kinetics remain unstudied. This study investigates 221s (2,9) elimination in rats to bridge this knowledge gap. Methods: Excretion of unchanged 221s (2,9) was quantified in urine, feces, and bile of Sprague-Dawley rats after oral administration (30 mg/kg). Concentrations of unchanged 221s (2,9) in all matrices were quantified using developed UPLC-MS/MS that underwent methodological validation. Excretion amount, excretion velocity, and accumulative excretion rate of 221s (2,9) were calculated. Results: Urinary excretion exhibited rapid elimination kinetics, reaching peak cumulative excretion rates (138.81 ± 15.56 ng/h) at 8 h post-dosing and plateauing by 48 h (cumulative excretion: 1479.81 ± 155.7 ng). Fecal excretion displayed an accelerated elimination phase between 4 and 8 h (excretion rate: 7994.29 ± 953.75 ng/h), followed by a sustained slow-release phase, culminating in a cumulative output of 36,726.31 ± 5507 ng at 48 h. Biliary excretion was minimal and ceased entirely by 24 h. Notably, total recovery of unchanged drug across all matrices remained below 1% (urine: 0.020 ± 0.021%; feces: 0.73 ± 0.069%; bile: 0.00044 ± 0.00002%) at 72 h. Conclusions: This study provides the first definitive excretion data for 221s (2,9). Quantitative analysis via a validated UPLC-MS/MS method revealed that fecal excretion is the principal elimination pathway for unchanged 221s (2,9) in rats, with direct excretion of the parent compound accounting for <1% of the administered dose over 72 h. Future studies will employ extended pharmacokinetic monitoring and concurrent UPLC-MS/MS analysis of the parent drug and phase II conjugates to resolve the observed mass imbalance and elucidate contributions to total elimination. Full article

The Ichubamba Yasepan wetlands, in the Andean páramos of Ecuador, suffer heavy metal contamination due to anthropogenic activities and volcanic ash from Sangay, impacting biodiversity and ecosystem services. This quasi-experimental study evaluated the bioaccumulation and tolerance of metals in high Andean species through stratified random sampling and linear transects in two altitudinal ranges. Concentrations of Cr, Pb, Hg, As, and Fe in water and the tissues of eight dominant plant species were analyzed using atomic absorption spectrophotometry, calculating bioaccumulation indices (BAIs) and applying principal component analysis (PCA), clustering, and linear discriminant analysis (LDA). Twenty-five species from 14 families were identified, predominantly Poaceae and Cyperaceae, with Calamagrostis intermedia as the most relevant (IVI = 12.74). The water exceeded regulatory limits for As, Cr, Fe, and Pb, indicating severe contamination. Carex bonplandii showed a high BAI for Cr (47.8), Taraxacum officinale and Plantago australis for Pb, and Lachemilla orbiculata for Hg, while Fe was widely accumulated. The LDA highlighted differences based on As and Pb, suggesting physiological adaptations. Pollution threatens biodiversity and human health, but C. bonplandii and L. orbiculata have phytoremediation potential. Full article

In contrast to mercury, an extremely toxic element, selenium is an essential micronutrient, which by complexing with mercury can mitigate its toxicity. In this regard, we quantified mercury and selenium concentrations in samples (n = 309) of fish tissues and analyzed the Se:Hg molar ratio and HBVSe as toxicological risk biomarkers. The data indicated that mercury levels in planktivorous fish (0.630 ± 0.202 mg kg⁻¹) and carnivorous fish (1.196 ± 0.513 mg kg⁻¹) were above the Brazilian limits considered safe for daily consumption. The highest selenium concentrations were observed in planktivores (0.272 ± 0.093 mg kg⁻¹) and the lowest in herbivores (0.099 ± 0.092 mg kg⁻¹). Molar ratios greater than one and positive HBVSe values were found in 42% of the fish samples (n = 131). As a result, we found that (i) the trophic level influences the risk of mercury exposure through the intake of fish in the diet; (ii) the approach presented in our study (model II) involves greater rigor concerning intake and exposure via fish consumption, since it considers the antagonistic Se:Hg ratio; and (iii) selenium can attenuate mercury toxicity, but safe thresholds vary depending on the species. Full article

Mercury (Hg) poses a significant threat to human health and ecosystems, garnering increased attention in environmental studies. This paper evaluates the dynamics of Hg accumulation in various common tree leaves, specifically white poplar, linden, and cherry plum, throughout their growing season. The findings offer valuable insights into air quality and the ability of urban vegetation to mitigate mercury pollution in urban areas. A case study was conducted in Turda, a town in northwestern Romania, where a former chlor-alkali plant operated throughout the last century. Although the plant ceased its electrolysis activities over 25 years ago, the surrounding soil remains contaminated with mercury (Hg) due to the significant amounts released during its operation. The results indicated that the Hg concentration varied between 2.4 and 7.3 mg kg⁻¹ dry weight (dw), exceeding the intervention threshold for soil of 2.0 mg kg⁻¹. Additionally, the Hg content in the leaf samples consistently increased over time, influenced by leaf age and tree species. The Hg content increased in the following order: cherry plum < white poplar < linden. On average, white poplar leaves accumulated 72 ng Hg g⁻¹ dw, linden leaves 128 ng Hg g⁻¹ dw, and cherry plum leaves 47 ng Hg g⁻¹ dw during the six-month monitored period from April to September. The results obtained can be used to evaluate the potential of different tree species for mitigating atmospheric Hg contamination and to elaborate on the suitable management of fallen leaves in the autumn. Full article

Background/Objectives: Serum 25-hydroxyvitamin D (25(OH)D) concentrations are decreased with metabolic syndrome (MetSy), and low serum 25(OH)D concentrations are associated with poor outcomes following anterior cruciate ligament (ACL) reconstruction (ACLR). It is unknown whether serum 25(OH)D concentrations are decreased in patients with MetSy following ACLR. The purpose of this study was to investigate whether serum 25(OH)D concentrations are decreased with MetSy following ACLR. Methods: This retrospective case–control study consisted of patients (≥18 years) who underwent ACLR. MetSy was defined as meeting any three of the five criteria (cases): (1) body mass index ≥ 30 kg/m², (2) triglycerides ≥ 150 mg/dL, (3) HDL < 40 mg/dL in men and <50 mg/dL in women, (4) systolic blood pressure ≥ 130 mmHg or diastolic blood pressure ≥ 85 mmHg, or (5) estimated (from hemoglobin A1c% [HbA1c]) fasting glucose ≥ 100 mg/dL. Participants without MetSy (meeting <3 criteria) served as controls. The first blood lipid, HbA1c, and 25(OH)D assessed ≥90 d after ACLR were included in this study. Results: The final analysis consisted of 219 patients (cases (with MetSy), n = 84; controls (without MetSy), n = 135). Serum 25(OH)D was significantly (p < 0.01) decreased (15.8%) in cases (mean [SD]; 25.1 [11.3] ng/mL) compared to controls (29.8 [14.8] ng/mL). An increasing number of MetSy components was associated with a decreased prevalence of vitamin D sufficiency (p < 0.01). Conclusions: We conclude that serum 25(OH)D concentrations are significantly lower with MetSy. These preliminary findings could provide justification for assessing serum 25(OH)D following ACLR in patients with MetSy and assist with risk stratification. Full article

Urban parks are an integral component of cities; however, they are susceptible to heavy metal contamination from anthropogenic sources. Here, we investigated the moss Pleurozium schreberi and tree leaves as bioindicators for monitoring heavy metal contamination in urban parks. We determined heavy metal concentrations in P. schreberi, leaf tissues of selected tree species, and soil samples collected from various locations within a designated urban parks. The order of heavy metal accumulation was Zn > Pb > Cr > Cu > Ni > Cd > Hg in soil and Zn > Cu > Pb > Cr > Ni > Cd > Hg in P. schreberi. The order was Zn > Cu > Cr > Ni > Pb > Cd > Hg in linden and sycamore leaves, while birch leaves displayed a similar order but with slightly more Ni than Cr. The heavy metal concentration in the tested soils correlated positively with finer textures (clay and silt) and negatively with sand. The highest metal accumulation index (MAI) was noted in birch and P. schreberi, corresponding to the highest total heavy metal accumulation. The bioconcentration factor (BAF) was also higher in P. schreberi, indicating a greater ability to accumulate heavy metals than tree leaves, except silver birch for Zn in one of the parks. Silver birch displayed the highest phytoremediation capacity among the analysed tree species, highlighting its potential as a suitable bioindicator in heavy metal-laden urban parks. Our findings revealed significant variation in heavy metal accumulation, highlighting the potential of these bioindicators to map contamination patterns. Full article

This study investigated ten potential toxic metals (PTMs) in six milk and dairy product types and evaluated food safety (TDI, RDA), human exposure (EDI), non-carcinogenic risk (THQ, HI), and contamination levels (CF, PLI). Based on total PTM load, products ranked as: children’s milk > yogurt > protein milk > milk > ayran > kefir. Aluminum (Al) showed the highest average concentration in all products except ayran, where manganese (Mn) was dominant. Cadmium (Cd), mercury (Hg), and lead (Pb) were consistently at the lowest levels. Except for chromium (Cr) exposure from children’s milk, all average and maximum EDI values stayed below TDI and RDA thresholds. Children’s milk had the highest non-carcinogenic risk, while yogurt, kefir, milk, and ayran may also pose potential risks when maximum HI values are considered. Although CF values varied across products, PLI results showed all products had high levels of PTM contamination. Given the widespread consumption of dairy across all age groups, especially by sensitive populations like children, monitoring and controlling PTM levels is crucial alongside ensuring nutritional quality. Full article

Background and purpose: Indigenous people in the Brazilian Amazon are exposed to mercury by eating methylmercury-contaminated fish. The lack of information on the health effects of prolonged exposure to mercury hinders the implementation of mitigation programs offered by the Brazilian government. This article aims to evaluate the studies that have investigated mercury exposure in indigenous people living in the Brazilian Amazon. Methods: A scoping review of the literature was conducted from studies published between 1995 and 2024 in Portuguese, English, and Spanish that evaluated mercury (Hg) concentrations in hair samples in indigenous people from the Brazilian Amazon. Results: Using total mercury (TotalHg) values in hair samples, we analyzed exposure levels, prevalence, and toxic effects. We found 15 epidemiological studies with a cross-sectional design and sample sizes ranging from 31 to 910 participants. Four studies involved children and mothers, four of which were associated with clinical outcomes and three of which analyzed genetic polymorphism. Most of the communities evaluated had a high prevalence of mercury exposure, showing levels ranging from 0.8 to 83.89 µg/g, and the highest average TotalHg concentration was found among the Kayabi. Mercury was associated with hypertension, cognitive disorders, worse mental health indicators and central and peripheral neurological disorders. Conclusions: It is concluded that indigenous people in the Brazilian Amazon experience exposure levels that are causing damage to their health, and control measures must be adopted to prevent the situation from worsening. Full article

Mercury is a highly toxic heavy metal that poses serious threats to human health and environmental safety, highlighting the critical importance of accurate Hg²⁺ detection. In this study, a novel fluorescent probe AP was synthesized by conjugating fluorescein, serving as the luminescent group, with pyridine-2-carboxaldehyde to enable selective Hg²⁺ detection. Hg²⁺ binds to AP in a 1:2 stoichiometric ratio, inducing the opening of the spiro-lactam ring and resulting in a significant fluorescence enhancement. The probe exhibited excellent selectivity and sensitivity toward Hg²⁺. A strong linear correlation was observed between its fluorescence intensity and Hg²⁺ concentration (R² = 0.99952), with a detection limit of as low as 9.75 × 10⁻⁸ mol/L. The average recoveries of Hg²⁺ across various water matrices ranged from 95.23% to 103.40%, with relative standard deviations (RSDs) below 3.07%. These results indicate that the probe performs effectively in real water-sample testing. Full article

Faxonius limosus is an invasive alien crayfish species that has a negative effect on aquatic biodiversity. Using its meat as food could help reduce its ecological impact while providing a protein source. In order to do that, the initial step was to determine safety and nutritional parameters of crayfish meat. Samples from two localities were analyzed for energy value, moisture, ash, protein, fat, carbohydrates, fatty acid and amino acid composition, and macro- and micro-mineral content. Moreover, an online survey was conducted in order to evaluate the public’s current knowledge about invasive alien species and willingness to consume crayfish meat as a food product. Heavy metal concentrations (Hg, Pb, Cd) were below European Commission limits, confirming safety. The meat had a high protein content (16.68%), low fat (0.22%), and a favorable fatty acid profile with notable levels of omega-3 polyunsaturated fatty acids, particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Predominant macro-minerals were K, Na, Ca, Mg, and P, while Zn, Cu, Fe, and Mn were the most abundant micro-minerals. Even though most participants (79.7%) were not informed about Faxonius limosus, the majority expressed willingness to participate in the assessment of new products made from invasive crayfish. These findings suggest that F. limosus meat is a nutritionally valuable and safe alternative protein source, with potential for sustainable food production and ecological management. Full article