Threshold and combined effects of heavy metals on the risk of phenotypic age acceleration among U.S. adults.

Accumulation of heavy metals in the body has been shown to affect the phenotypic age (PhenoAge). However, the combined and threshold effects of blood heavy metals on the risk of PhenoAge acceleration (PhenoAgeAccel) are not well understood. A cross-sectional study was conducted using blood heavy metal data (N = 7763, age ≥18 years) from the 2015-2018 National Health and Nutrition Examination Survey. PhenoAgeAccel was calculated from actual age and nine biomarkers. Multiple regression equations were used to describe the relationship between heavy metals and PhenoAgeAccel. Least Absolute Shrinkage and Selection Operator (LASSO) regression modeling was used to explore the relationship between the combined effects of heavy metals and PhenoAgeAccel. Threshold effect and multiple regression analyses were performed to explore the linear and nonlinear relationships between heavy metals and PhenoAgeAccel. Threshold effect analysis showed that blood mercury (Hg) concentration was linearly associated with PhenoAgeAccel. In contrast, lead (Pb), cadmium (Cd), manganese (Mn), and combined exposure were nonlinearly associated with PhenoAgeAccel. In addition, the combination of Pb, Cd, Hg, and Mn significantly affected PhenoAgeAccel. The risk of PhenoAgeAccel was increased by 207% (P < 0.0001). Meanwhile, a threshold relationship was found between blood Pb, Cd, Mn, and the occurrence of PhenoAgeAccel. Overall, our results indicate that combined exposure to heavy metals may increase the risk of PhenoAgeAccel. This study underscores the need to reduce heavy metal pollution in the environment and provides a reference threshold for future studies.

Ultrahigh Detectivity Broad Spectrum UV Photodetector with Rapid Response Speed Based on p-ß Ga2 O3 /n-GaN Heterojunction Fabricated by a Reversed Substitution Doping Method.

An excellent broad-spectrum (220-380 nm) UV photodetector, covering the UVA-UVC wavelength range, with an ultrahigh detectivity of ≈1015  cm Hz1/2 W-1 , is reported. It is based on a p-ß Ga2 O3 /n-GaN heterojunction, in which p-ß Ga2 O3 is synthesized by thermal oxidation of GaN and a heterostructure is constructed with the bottom n-GaN. XRD shows the oxide layer is (-201) preferred oriented ß-phase Ga2 O3 films. SIMS and XPS indicate that the residual N atoms as dopants remain in ß Ga2 O3 . XPS also demonstrates that the Fermi level is 0.2 eV lower than the central level of the band gap, indicating that the dominant carriers are holes and the ß Ga2 O3 is p-type conductive. Under a bias of -5 V, the photoresponsivity is 56 and 22 A W-1 for 255 and 360 nm, respectively. Correspondingly, the detectivities reach an ultrahigh value of 2.7 × 1015  cm Hz1/2 W-1 (255 nm) and 1.1 × 1015  cm Hz1/2 W-1 (360 nm). The high performance of this UV photodetector is attributed mainly to the continuous conduction band of the p-ß Ga2 O3 /n-GaN heterojunction without a potential energy barrier, which is more helpful for photogenerated electron transport from the space charge region to the n-type GaN layer.

Association Between Different Inflammatory Markers and Generalized Abdominal Obesity: A Cross-Sectional Study.

PURPOSE: Inflammation is strongly correlated with obesity. However, very few studies have reported associations between novel inflammatory markers, such as the neutrophil-to-lymphocyte ratio (NLR), systemic immune-inflammation index (SII), C-reactive protein (CRP), and C-reactive protein-to-albumin ratio (CAR), and different obesity types. Therefore, this study aimed to explore the associations of these inflammatory markers with generalized and abdominal obesity. MATERIALS AND METHODS: This cross-sectional study included data from 2015 to 2018 obtained from the National Health and Nutrition Examination Survey. Multivariate regression analysis was performed to determine the associations between different inflammatory biomarkers and obesity. The discriminative capacities of the markers for obesity types were depicted using receiver operating characteristic (ROC) curves, with corresponding area under the curve (AUC) metrics quantifying this discrimination. RESULTS: After adjusting for confounding variables, generalized obesity was found to be positively associated with an increased risk of NLR by 35%, SII by 52%, CRP by 941%, and CAR by 925%, compared with the reference groups. In the model, the CRP concentration and CAR demonstrated high AUC values of 0.690 and 0.889, respectively, for the identification of generalized and abdominal obesity (P < 0.05). CONCLUSION: This study revealed associations between obesity and inflammatory biomarkers, such as the NLR, SII, CRP, and CAR. CRP is the most sensitive marker for generalized obesity, while CAR shows the strongest association with abdominal obesity. These findings suggest that inflammatory biomarkers may be useful for assessing and managing obesity-related health concerns.

Gender differences in the relationship between nicotine exposure and symptoms of depression.

BACKGROUND: Tobacco-derived nicotine exposure is linked to depression. However, the associations of nicotine and its metabolites with symptoms of depression, particularly concerning gender differences, remain underexplored. METHODS: The characteristics and total nicotine equivalents (TNE) of 1001 subjects were determined. The association between the TNE and symptoms of depression, accounting for gender differences, was investigated using generalized linear models and subgroup analyses. RESULTS: Men exhibited significantly greater levels of the nicotine exposure indicators TNE2, TNE3, TNE6, and TNE7 (P < 0.005). A significantly greater percentage of women (23.45 %) than men (9.81 %) exhibited symptoms of depression (P < 0.0001). In women, the relationship between the TNE and depression was reflected by a U-shaped curve with significant inflection points, particularly for TNE3, TNE6, and TNE7. Furthermore, in women, concentrations above 48.98 nmol/mL for TNE3, 53.70 nmol/mL for TNE6, and 57.54 nmol/mL for TNE7 were associated with 154 %, 145 %, and 138 % increases in the risk of depression, respectively. In contrast, these associations did not reach significance among men. LIMITATIONS: The cross-sectional design limits the ability to infer causality between nicotine exposure and depressive symptoms. Larger-scale studies are needed to confirm these findings. CONCLUSIONS: Gender could be a significant factor influencing the relationship between nicotine exposure levels and symptoms of depression. The impact of nicotine exposure on symptoms of depression should be particularly considered among women. IMPLICATIONS: This study revealed the complex relationship between tobacco-related nicotine exposure and depressive symptoms, with a particular focus on gender differences. Our results revealed a distinct U-shaped correlation between total nicotine equivalents and depression in women, which differed from that in men. These findings emphasize the importance of tailoring clinical approaches to address nicotine exposure and manage depressive symptoms based on gender.

Rapid Response Solar Blind Deep UV Photodetector with High Detectivity Based On Graphene:N/ßGa2 O3 :N/GaN p-i-n Heterojunction Fabricated by a Reversed Substitution Growth Method.

This work reports a high-detectivity solar-blind deep ultraviolet photodetector with a fast response speed, based on a nitrogen-doped graphene/ßGa2 O3 /GaN p-i-n heterojunction. The i layer of ßGa2 O3 with a Fermi level lower than the central level of the forbidden band of 0.2 eV is obtained by reversed substitution growth with oxygen replacing nitrogen in the GaN matrix, indicating the majority carrier is hole. X-ray diffractometershows that the transformation of GaN into ßGa2 O3 with (-201) preferred orientation at temperature above 900 °C in an oxygen ambient. The heterojunction shows enhanced self-powered solar blind detection ability with a response time of 3.2 µs (rise)/0.02 ms (delay) and a detectivity exceeding 1012 Jones. Under a reverse bias of -5 V, the photoresponsivity is 8.3 A W-1 with a high Ilight /Idark ratio of over 106 and a detectivity of ≈9 × 1014 Jones. The excellent performance of the device is attributed to 1) the continuous conduction band without a potential energy barrier, 2) the larger built-in potential in the heterojunction because of the downward shift of Fermi energy level in ß-Ga2 O3 , and 3) an enhanced built-in electric field in the ßGa2 O3 due to introducing p-type graphene with a high hole concentration of up to ≈1020 cm-3 .

High-Performance Solar-Blind Ultraviolet Photodetectors Based on ß-Ga2O3 Thin Films Grown on p-Si(111) Substrates with Improved Material Quality via an AlN Buffer Layer Introduced by Metal-Organic Chemical Vapor Deposition.

We have achieved significantly improved device performance in solar-blind deep-ultraviolet photodetectors fabricated from ß-Ga2O3 thin films grown via metal-organic chemical vapor deposition (MOCVD) on p-Si(111) substrates by improving material quality through the use of an AlN buffer layer. High-structural-quality ß-Ga2O3 films with a (-201) preferred orientation are obtained after the introduction of the AlN buffer. Under 3 V bias, the dark current reaches a minimum of 45 fA, and the photo-to-dark current ratio (PDCR) reaches 8.5 × 105 in the photodetector with the metal-semiconductor-metal (MSM) structure. The peak responsivity and detectivity are 38.8 A/W and 2.27 × 1015 cm·Hz1/2/W, respectively, which are 16.5 and 230 times that without the buffer layer. Additionally, benefiting from the introduction of the AlN layer, the photodetection performance of the ß-Ga2O3/AlN/Si heterojunction is significantly improved. The PDCR, peak responsivity, and detectivity for the ß-Ga2O3/AlN/p-Si photodetector at 5 V bias are 2.7 × 103, 11.84 A/W, and 8.31 × 1013 cm·Hz1/2/W, respectively. The improved structural quality of ß-Ga2O3 is mainly attributed to the decreased in-plane lattice mismatch of 2.3% for ß-Ga2O3(-201)/AlN(002) compared to that of 20.83% for ß-Ga2O3(-201)/Si(111), as well as the elimination of the native amorphous SiOx surface layer on the Si substrate during the initial growth of oxide thin films.