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In this work, a portable surface-enhanced Raman spectroscopy (SERS) substrate based on perovskite-like PbBiO2Br/AuAg hybrid nanoalloys (PbBiO2Br/Au4Ag4 nanospheres) was fabricated for the rapid, sensitive, and selective detection of formaldehyde. PbBiO2Br nanospheres with thin nanosheets on the surface of the microsphere structure were synthesized via the hydrothermal method. The formation of nanospheres was controlled by an ionic liquid ([C16mim]+). [C16mim]+ can be simultaneously used as a solvent, reactant, and template for fabricating a porous microstructure of PbBiO2Br nanospheres. AuAg nanoalloys were grown on PbBiO2Br nanospheres in situ in the presence of Au3+ and Ag+. SERS performance was further optimized by adjusting the ratio of Au/Ag. PbBiO2Br/Au4Ag4 membranes as the SERS substrate were further obtained via simple filtration of the PbBiO2Br/Au4Ag4 nanospheres on filter paper. The PbBiO2Br/Au4Ag4 membranes displayed better SERS activity for molecules with an −SH group than for molecules with nonsulfhydryl targets owing to the high affinity between AuAg nanoalloys and −SH. Under optimum conditions, the method developed herein determined that the analytical enhancement factor of 4-mercaptobenzoic acid and 4-nitrothiophenol could reach 4.5 × 108 and 3.2 × 107, respectively. The proposed strategy showed a wide linear range (20.0–500.0 μg L–1) and a low limit of detection (2.6 μg L–1) for formaldehyde determination. The membrane-based substrate developed in this study offers a novel strategy for fabricating portable and reliable SERS substrates and provides a valid SERS method for rapid on-site monitoring of formaldehyde. [ABSTRACT FROM AUTHOR]

With the wide use of rare earth nanomaterials in industry, environmental control, and medicine with their unique properties, it has focused on the exposure of humans to the rare earth nanoparticles in recent years. Because of the similar properties of rare earth and calcium, rare earth nanoparticles can deposit in the bone and affect the osteogenic differentiation of bone mesenchymal stem cells (BMSCs). La(OH)3 nanoparticles are widely used in the catalysis, sensor, electrode, and luminescent materials. However, there are few reports about the bioactivity of La(OH)3 nanoparticles on the bone metabolism. In this work, three La(OH)3 nanorods have been got by hydrothermal method, Long-, Medium-, and Short-La(OH)3 nanorods, the lengths of which were of ~ 640, 255, and 80 nm, and the diameters of which were of ~ 85, 40, and 35 nm, respectively. All the La(OH)3 nanorods showed no effect on BMSCs viability and the blood compatibility. But the osteogenic differentiation showed a significant difference in La(OH)3 nanorods, in which Short-La(OH)3 nanorods showed the highest promoting effect on osteogenic differentiation. The potential mechanism in the osteogenic differentiation caused by three La(OH)3 nanorods was correlated with the different uptake efficiency in BMSCs and degradation in lysosome to form LaPO4. This work on La(OH)3 nanorods provides the basic data for the development of lanthanum-based nanoparticles. [ABSTRACT FROM AUTHOR]

Hyocholic acid (HCA) is a major bile acid (BA) species in the BA pool of pigs, a species known for its exceptional resistance to spontaneous development of diabetic phenotypes. HCA and its derivatives are also present in human blood and urine. We investigate whether human HCA profiles can predict the development of metabolic disorders. We find in the first cohort (n = 1107) that both obesity and diabetes are associated with lower serum concentrations of HCA species. A separate cohort study (n = 91) validates this finding and further reveals that individuals with pre-diabetes are associated with lower levels of HCA species in feces. Serum HCA levels increase in the patients after gastric bypass surgery (n = 38) and can predict the remission of diabetes two years after surgery. The results are replicated in two independent, prospective cohorts (n = 132 and n = 207), where serum HCA species are found to be strong predictors for metabolic disorders in 5 and 10 years, respectively. These findings underscore the association of HCA species with diabetes, and demonstrate the feasibility of using HCA profiles to assess the future risk of developing metabolic abnormalities. The early identification of metabolic disorders could improve or prevent overt disease. Here the authors show that the circulating concentration of hyocholic acid (HCA) species is decreased in the context of obesity and diabetes and increased after gastric bypass surgery in humans, and further that serum HCA species are predictive of metabolic outcomes in healthy individuals. [ABSTRACT FROM AUTHOR]

Excessive reactive oxygen species (ROS) would attack living cells and cause a series of oxidative stress related diseases, such as liver damage. Hydroxyl radicals (·OH) are currently known as one of the most toxic and harmful free radicals to organisms. Therefore, studies involving hydroxyl radicals have become important research topics in the fields of biology, biochemistry, and biomedicine. In addition, imaging of analytes using upconversion nanoparticles (UCNPs) possesses significant advantages over that using general fluorescent dyes or nanoparticles due to its high spatial resolution, reduced photodamage, and deep tissue penetration properties. Herein, we designed a highly selective and sensitive hydroxyl radical nanoprobe based on the luminescence resonance energy transfer between upconversion nanoparticles and methylene blue (MB). The concentration of ·OH could be determined by the fluorescence recovery of the UCNPs due to the oxidative damage of MB. Using this nanoprobe, the ·OH in living cells or in liver tissues could be monitored with high sensitivity and selectivity. [ABSTRACT FROM AUTHOR]

• Novel analysis framework for the Green Transition of Urban Land Use. • Long-term, wide-area data reveals temporal and spatial differences in transition. • Focus on the spatial convergence of Green Transition of Urban Land Use. • Regional heterogeneity in the spatial convergence effect. Revealing the spatial differences and the convergence mechanisms of Green Transition of Urban Land Use (GTULU) in the context of industrial integration is of great significance for formulating differentiated industrial development strategies, accelerating the process of industrial integration, and exploring synergistic enhancement paths of GTULU. In this paper, 107 prefecture-level and above cities in the Yangtze River Economic Belt (YREB) are taken as research objects, and the entropy value method, exploratory spatial data analysis model and spatial convergence model are comprehensively applied to analyze the spatio-temporal differences and spatial convergence of the GTULU under the background of industrial integration. The study shows that: (1) from 2003 to 2021, the level of GTULU in the YREB has been increasing, with the mean value growing from 0.09 to 0.14, but there are still significant spatial differentiation and spatial correlation characteristics, and the regional imbalance phenomenon of GTULU is more and more obvious as time goes by. (2) The GTULU of the YREB and its upstream, midstream, and downstream regions all exhibit a temporal evolution characteristic of increasing fluctuations. (3) There is no σ-convergence in GTULU in the YREB and its upstream, middle-stream, and downstream regions. However, there are all significant absolute β convergence and conditional β convergence. Moreover, under the combined influence of government management, technological input, industrial structural adjustment, and spatial impact, the convergence rate of the YREB has significantly accelerated, from 1.98% to 2.31%, and the convergence effect exhibits marked heterogeneity. [ABSTRACT FROM AUTHOR]

The original article can be found online at https://doi.org/10.1007/s00216-022-03876-0.Correction to: Analytical and Bioanalytical Chemistry (2022) 414:2385–2395https://doi.org/10.1007/s00216-022-03876-0The original article has been corrected.Author Kun Ge should only be affiliated to: School of Chemistry, Sun Yat-sen University, Guangzhou 510006, China.Publisher's NoteSpringer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.By Kun Ge; Yonghui Li; Qiyue Wu and Ying GuReported by Author; Author; Author; Author [Extracted from the article]

The exploitation of natural gas hydrate, an unconventional natural gas, has drawn attention on a global scale due to increasing imbalance between energy supply and demand. Horizontal wells are considered to have a better production performance, while vertical wells have been mostly employed in previous field tests and laboratory research. Therefore, based on the representative properties of three kinds of hydrate reservoirs, a hydrate decomposition model is built to study the gas generation behaviors of various hydrate reservoirs with different horizontal well-spacing strategies in this work. The results show that for Class I hydrate reservoirs, placing the production well near the free gas layer can improve gas generation by 47%, and GWR (gas-water ratio) to 346.0 and maintain higher temperature in hydrate reservoir than that with placing the well in the hydrate reservoir. For Class Ⅱ hydrate reservoirs, placing the producing well away from the free water layer can cut down water production by 92%, while gas production could be also elevated, causing GWR increasing to 175.8. In Class Ⅲ reservoirs, the reduction of 30% in water production, and increment in GWR from 81.5 to 118.0 can be achieved by placing the well on the top of the hydrate layer, rather than that on the bottom. In addition, the presence of free gas layer, free water layer can promote the pressure-drop interface spread, provide sensible heat, and then accelerate hydrate decomposition further. [Display omitted] • Gas behavior in different reservoirs and horizontal well locations were studied. • Placing bottom-well patterns can increase gas production in Class I reservoir. • Placing middle-well patterns can get higher gas-water ratio in Class II reservoir. • Placing upper-well patterns can get higher gas yield rate in Class III reservoir. • Free air and water layers can promote pressure drop diffusion and provide heat. [ABSTRACT FROM AUTHOR]