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Mercury ions (Hg2+), a heavy metal contaminant of strong biotoxicity, pose a serious threat to ecosystems and human health in aquatic environments. Developing highly sensitive and specific detection methods is therefore of great importance. This study presents a novel label-free fluorescent biosensor for Hg2+ by ingeniously coupling target-induced aptamer switching with rolling circle amplification (RCA). Upon Hg2+ binding, the conformational change releases a sequestered primer to initiate RCA, generating G-quadruplex-rich DNA products that produce a strong “turn-on” signal with N-methylmesoporphyrin IX (NMM). Under optimized conditions, the assay exhibits excellent linearity from 10 to 1000 nM with a detection limit of 3.2 nM, along with high selectivity over competing metal ions. Validation using spiked environmental water samples yielded accurate and reproducible recoveries in the range of 93.8% to 106.0%. With its operational simplicity, high sensitivity, and robust performance in complex matrices, this label-free strategy offers a reliable and promising platform for detecting Hg2+ in environmental waters.

Background Acute lung injury (ALI) is a critical pulmonary condition characterized by high morbidity and mortality rates. Recent studies have highlighted the therapeutic potential of engineered exosomes derived from mesenchymal stem cell (MSC) in modulating the inflammatory response in ALI. Here, a novel approach was developed to fabricate engineered bone mesenchymal stem cells (BMSCs) derived exosomes by utilizing superparamagnetic iron oxide nanoparticles (SPIONs) and an alternating magnetic field (AMF) to precondition BMSCs. This study evaluated and compared the therapeutic potential of different groups of engineered exosomes in ALI mice model and analyzed their underlying mechanisms using high-throughput sequencing. Methods BMSCs were isolated from SD rats and subjected to treatment with SPIONs and/or an AMF. Following this, we established a lipopolysaccharide (LPS)-induced ALI mice model and evaluated the therapeutic efficacy of exosomes from different groups by administering them via tail vein injection. The expression profiles of microRNAs (miRNAs) in exosomes were compared to explore the mechanism of regulating inflammatory response and ameliorating lung injury. Results 25 µg/mL SPIONs and 3mT AMF were the best conditions for preparing engineered exosomes, which reduced the level of pro-inflammatory factors and had the most significant effect in repaired lung damage in vivo. The transfection of miR-145-5p mimics enhanced Bronchial Epithelium transformed with Ad12-SV40 2B (BEAS-2B) cells viability and reduced relevant inflammation expression in vitro experiments. Conclusion The engineered exosomes obtained by low dose SPIONs combined with AMF can help regulate the level of inflammatory factors and improve lung injury. Targeted regulation of kruppel-like factor 5 (KLF5) by exosomal miR-145-5p and inhibition of the activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway play a key role in this vitro process.

Knowing the distributions and changes in global wetlands and their conversion to other land cover types could facilitate our understanding of wetland development, causes of variations, and decision-making for restoration and protection. This study aimed to comprehensively analyze the changes in wetland distributions at global, continental, typical regional, and national scales and the conversions between wetlands and other land cover types in the last 20 years. This study used GlobeLand30 (GL30) data with a 30 m resolution for the years 2000, 2010, and 2020. The main findings of this study are as follows: (1) the area of wetlands continued to increase globally from 2000 to 2020, with a total increase of approximately 4%. Wetland changes from 2010 to 2020 were more significant than those from 2000 to 2010. The regions with significant wetland changes were mainly in the north middle- and high-latitude, and the equatorial middle- and low-latitude, and Oceania and North America were the continents with the highest increase and decrease, respectively; (2) the major conversion of wetlands was mainly natural land cover types, including forest, grassland, water, and tundra, and there were minor conversions due to human activities, including the conversion of wetlands to cropland (~4600 km2) and artificial land (~3400 km2); (3) from 2000 to 2020, the increase in global wetlands was uneven, while the decrease was nearly even at a national scale. Australia had the highest increase due to the conversions from grass, bare land, and water, and Canada had the highest decrease due to the conversion into tundra and forest. The analysis results could more comprehensively characterize the distributions and changes of global wetlands, which may provide basic information and knowledge for related research work and policymaking.

Treatment for bone and joint tuberculosis (BJTB) is challenging due to its refractory and recurrent nature. This study aimed to develop a bioimplantable scaffold with osteoinductive and antituberculosis characteristics to treat BJTB. This scaffold is built on oxidized hyaluronic acid and carboxymethyl chitosan hydrogel mixed with hydroxyapatite as a bone tissue engineered material. In order to make the scaffold have the biological activity of promoting tissue repair, the engineered exosomes (Exo ) were added innovatively. In addition, drug-loaded liposomes equipped with an aldehyde group on the surface are cross-linked with the amine group of the hydrogel skeleton to participate in the Schiff base reaction. The designed scaffold has characteristics of self-healing and injectability exhibit excellent anti-tuberculosis and promoting bone repair activities. Exo strongly stimulates cellular angiogenesis and osteogenic differentiation. The liposomes coated in hydrogel can release three kinds of anti-tuberculosis drugs smoothly and slowly, achieving a long term anti-tuberculosis. The composite bio-scaffold shows good tissue repair and long-term anti-tuberculosis abilities, which expected to provide a viable treatment plan for bone-related BJTB.

Landscape architecture with urban green space as the main research object is an evidence-based science. It is an important issue to optimize green space systems from the point of view of ecosystem services. In this paper, high-resolution (1.5 m resolution) remote sensing images are combined with data-processing software, such as ENVI, ArcGIS, and Fragstats, to evaluate ecosystem service quality and compute the landscape pattern in the Haidian District (Beijing, China), so that the relationship between the ecosystem service quality and landscape pattern can be quantitatively studied and a strategy can be provided for green space optimization in cities. The following conclusions are drawn: (1) for the evaluated quality of 14 ecosystem services in Haidian District (refer to Section Analysis of the Association of the Percentage of Patches (PLAND) Index of Forest Land and Quality of Ecosystem Service in Haidian District). Forest land is the main provider of the ecosystem service in Haidian District, while construction land only provides cultural services; (2) on the whole, the spatial distribution of the ecosystem services in Haidian District gradually decreases from the west to the east, which basically matches with the spatial distribution of the forest land. The regulating service and supporting service are matched with the distribution of the urban green space. The cultural service is closely associated with history resource points; and (3) the analysis results of the association between landscape pattern and ecosystem service quality show that the percentage of patches (PLAND) index for forest land has a significant logarithmic relationship with the regulating service and supporting service. The critical value of the PLAND index is 30. Besides the Xishan area with the most coverage of forest land, the landscape shape index (LSI) of the brushwood has a logarithmic relationship with the ecosystem service quality. The critical value of the LSI value is 50. Finally, this paper proposes an area optimization strategy of green space in Haidian District from the view of the ecosystem system service. The Xishan area is classified into the ecosystem red line to control city expansion. The regulating and supporting services can be enhanced in the north flat area by improving the patch shape index. The ecosystem service capabilities can be improved by adding the forest land in the existing green space for the southeast urban areas.

Dysfunction of striatal medium spiny neurons (MSNs) is implicated in several neurological disorders, including Huntington’s disease (HD). Despite progress in characterizing MSN pathology in HD, mechanisms underlying MSN susceptibility remain unknown, driving the need for MSNs derived from human pluripotent stem cells (hPSCs), especially subtypes in research and therapy. Here, we established a scalable 3D-default culture system to produce striatal MSNs efficiently from hPSCs by activation of the endogenous sonic hedgehog (SHH) pathway. These cells expressed canonical markers of striatal progenitors and dopamine D1 (D1) and dopamine D2 (D2) MSNs and presented dynamic specification and transcriptional signatures that closely resemble endogenous MSNs at single-cell resolution, both in vitro and post-transplantation in HD mice with quinolinic acid (QA) lesions. Grafted human cells survived and matured into D1-/D2-like MSNs and projected axons to endogenous targets including globus pallidus externus, globus pallidus internus, and substantia nigra pars reticulata to reconstruct the basal ganglia pathways. Functionally, they displayed spontaneous synaptic currents, received regulation from host cortex and thalamus, and were modulated by dopamine to either enhance or reduce neuronal excitability, similar to the endogenous D1-/D2-MSNs, subsequently improving behavior in QA-lesioned HD mice. Our study presents a method for generating authentic MSNs, providing a reliable cell source for HD cell therapy, mechanistic studies, and drug screening.

Dysfunction of striatal medium spiny neurons (MSNs) is implicated in several neurological disorders, including Huntington's disease (HD). Despite progress in characterizing MSN pathology in HD, mechanisms underlying MSN susceptibility remain unknown, driving the need for MSNs derived from human pluripotent stem cells (hPSCs), especially subtypes in research and therapy. Here, we established a scalable 3D-default culture system to produce striatal MSNs efficiently from hPSCs by activation of the endogenous sonic hedgehog (SHH) pathway. These cells expressed canonical markers of striatal progenitors and dopamine D1 (D1) and dopamine D2 (D2) MSNs and presented dynamic specification and transcriptional signatures that closely resemble endogenous MSNs at single-cell resolution, both in vitro and post-transplantation in HD mice with quinolinic acid (QA) lesions. Grafted human cells survived and matured into D1-/D2-like MSNs and projected axons to endogenous targets including globus pallidus externus, globus pallidus internus, and substantia nigra pars reticulata to reconstruct the basal ganglia pathways. Functionally, they displayed spontaneous synaptic currents, received regulation from host cortex and thalamus, and were modulated by dopamine to either enhance or reduce neuronal excitability, similar to the endogenous D1-/ 02-М5 М5, subsequently improving behavior in QA-lesioned HD mice. Our study presents a method for generating authentic MSNs, providing a reliable cell source for HD cell therapy, mechanistic studies, and drug screening.

Urban green spaces encourage outdoor activity and social communication that contribute to the health of local residents. Examining the relationship between the use of urban green spaces and factors influencing their utilization can provide essential references for green space site selection in urban planning. In contrast to previous studies that focused on internal factors, this study highlights the external factors (traffic convenience, population density and commercial facilities) contributing to the use of urban green spaces. We conducted a spatiotemporal analysis of the distribution of visitors in 208 selected green spaces in central Beijing. We examined the relationship between the spatial pattern of visitor distribution within urban green spaces and external factors, using the Gini coefficient, kernel density estimation, and geographical detectors. The results of the study were as follows. The spatial distribution of visitors within central Beijing’s green spaces was concentrated, forming different agglomerations. The three examined external factors are all associated with the use of green spaces. Among them, commercial facilities are the important external factor associated with the use of green spaces. For the selection of sites for urban green spaces, we recommend consideration of external factors in order to balance urban green space utilization.

Mercury ions (Hg[sup.2+]), a heavy metal contaminant of strong biotoxicity, pose a serious threat to ecosystems and human health in aquatic environments. Developing highly sensitive and specific detection methods is therefore of great importance. This study presents a novel label-free fluorescent biosensor for Hg[sup.2+] by ingeniously coupling target-induced aptamer switching with rolling circle amplification (RCA). Upon Hg[sup.2+] binding, the conformational change releases a sequestered primer to initiate RCA, generating G-quadruplex-rich DNA products that produce a strong “turn-on” signal with N-methylmesoporphyrin IX (NMM). Under optimized conditions, the assay exhibits excellent linearity from 10 to 1000 nM with a detection limit of 3.2 nM, along with high selectivity over competing metal ions. Validation using spiked environmental water samples yielded accurate and reproducible recoveries in the range of 93.8% to 106.0%. With its operational simplicity, high sensitivity, and robust performance in complex matrices, this label-free strategy offers a reliable and promising platform for detecting Hg[sup.2+] in environmental waters.

To investigate the mechanisms of Yangxuetongmai Decoction in treating essential hypotension using network pharmacology, Mendelian randomization, and molecular docking strategy analysis. Active ingredients of Yangxuetongmai Decoction were identified from the TCMSP database, and target proteins were predicted. Essential hypotension proteins were sourced from GeneCards, OMIM, PharmGKB, TTD, and DrugBank and standardized via UniProt. Drug-disease protein interactions were analyzed with STRING and Cytoscape to identify core targets. GO, and KEGG enrichment was performed using R. Mendelian randomization, which assessed causal links and molecular docking validated interactions. 47 active ingredients and 230 potential targets were identified, with core targets including MAPK3, IL10, PRKCA, and APOB. Enriched pathways—PI3K-AKT, TNF, IL-17, MAPK, and calcium—were linked to essential hypotension. Mendelian randomization confirmed the protective effects of core targets, while molecular docking showed a strong binding affinity with bioactive compounds. Major components, such as β-sitosterol, formononetin, Kaempferol, luteolin, naringenin, and quercetin, may alleviate essential hypotension by modulating PI3K-AKT, TNF, IL-17, MAPK, and calcium pathways through interactions with core proteins. [Display omitted]