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Presumed source specificity of branched glycerol dialkyl glycerol tetraethers (brGDGTs) from bacteria thriving in soil/peat and isoprenoid GDGTs (iGDGTs) from aquatic organisms led to the development of several biomarker proxies for biogeochemical cycle and paleoenvironmental reconstructions. However, recent studies reveal that brGDGTs are also produced in aquatic environments besides soils and peat. Here we examined three cores from the Bohai Sea, and found distinct difference in brGDGT compositions varying with the distance from the Yellow River mouth. We thus propose an abundance ratio of hexamethylated to pentamethylated brGDGT (IIIa ∕ IIa) to evaluate brGDGT sources. The compilation of globally distributed 1354 marine sediments and 589 soils shows that the IIIa ∕ IIa ratio is generally < 0.59 in soils and 0.59–0.92 and > 0.92 in marine sediments with and without significant terrestrial inputs, respectively. Such disparity confirms the existence of two sources for brGDGTs, a terrestrial origin with lower IIIa ∕ IIa and a marine origin with higher IIIa ∕ IIa, which is likely attributed to a generally higher pH and the production of brGDGTs in cold deep water in marine waters. The application of the IIIa ∕ IIa ratio to the East Siberian Arctic Shelf proves it to be a sensitive source indicator for brGDGTs, which is helpful for accurate estimation of organic carbon source and paleoclimates in marine settings.

Severe polysulfide shuttling and sluggish redox kinetics critically hinder lithium–sulfur (Li-S) battery commercialization. In this study, a multifunctional diatomite (DE)/TiO2/MoS2/N-doped carbon nanofiber (NCNF) composite separator was fabricated via hydrothermal synthesis, electrospinning, and carbonization. DE provides dual polysulfide suppression, encompassing microporous confinement and electrostatic repulsion. By integrating synergistic catalytic effects from TiO2 and MoS2 nanoparticles, which accelerate polysulfide conversion, and conductive NCNF networks, which facilitate rapid charge transfer, this hierarchical design achieves exceptional electrochemical performance: a 1245.6 mAh g−1 initial capacity at 0.5 C and 65.94% retention after 200 cycles. This work presents a rational multi-component engineering strategy to suppress shuttle effects in high-energy-density Li-S batteries.

Oxygen in marine sediments regulates many key biogeochemical processes, playing a crucial role in shaping Earth’s climate and benthic ecosystems. In this context, branched glycerol dialkyl glycerol tetraethers (brGDGTs), essential biomarkers in paleoenvironmental research, exhibit an as-yet-unresolved association with sediment oxygen conditions. Here, we investigated brGDGTs in sediments from three deep-sea regions (4045 to 10,100 m water depth) dominated by three respective trench systems and integrated the results with in situ oxygen microprofile data. Our results demonstrate robust correlations between diffusive oxygen uptake (DOU) obtained from microprofiles and brGDGT methylation and isomerization degrees, indicating their primary production within sediments and their strong linkage with microbial diagenetic activity. We establish a quantitative relationship between the Isomerization and Methylation index of Branched Tetraethers (IMBT) and DOU, suggesting its potential validity across deep-sea environments. Increased brGDGT methylation and isomerization likely enhance the fitness of source organisms in deep-sea habitats. Our study positions brGDGTs as a promising tool for quantifying benthic DOU in deep-sea settings, where DOU is a key metric for assessing sedimentary organic carbon degradation and microbial activity. Xiao et al. uncover a strong linkage between marine bacterial tetraether lipids and benthic oxygen uptake in deepsea trench regions, indicating their potential for assessing microbial diagenetic activity and organic carbon degradation.

Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are useful molecular indicators for organic carbon (OC) sources and the paleoenvironment. Their application in marine environments, however, is complicated because of a mixed terrestrial and marine source. Here, we examined brGDGTs in sediments from the Mariana Trench, the deepest ocean without significant terrestrial influence. Our result shows a strong predominance of hexamethylated 6-methyl brGDGT (IIIa′) (73.40±2.39 % of total brGDGTs) and an absence of 5-methyl brGDGTs, different from previously reported soils and marine sediments that comprised both 5-methyl and 6-methyl brGDGTs. This unique feature, combined with high δ13COC (-19.82±0.25 %), low OC∕TN ratio (6.72±0.84), low branched and isoprenoid tetraether (BIT) index (0.03±0.01), and high acyclic hexa- ∕ pentamethylated brGDGT ratio (7.13±0.98), support that brGDGTs in the Mariana Trench sediments are autochthonous rather than terrestrial products. The compiling of literature data shows that the enhanced fractional abundance of hexamethylated 6-methyl brGDGTs is a common phenomenon in continental margins when the marine influence was intensified. The cross plot of acyclic hexa- ∕ pentamethylated brGDGT ratio and fractional abundance of brGDGT IIIa′ provide a novel approach to distinguish terrestrial and marine-derived brGDGTs.

Hydroxylated isoprenoid glycerol dialkyl glycerol tetraethers (OH‐GDGTs) preserved in marine sediments are thought to be controlled by sea surface temperature (SST). However, water depth may also exert a significant influence on OH‐GDGTs. Here, we investigated sedimentary OH‐GDGTs in the Kermadec and Atacama trench regions (2,560–9,560 m water depth). Sedimentary OH‐GDGTs in hadal trenches were dominated by OH‐GDGT‐0 (72 ± 8%), potentially reflecting an adaption of source organisms to ambient cold deep water. This result, combined with global data set, revealed that the predominance of OH‐GDGT‐0 is a ubiquitous phenomenon in deep‐sea sediments, leading to a considerable underestimation of RI‐OH′‐derived SSTs. By considering both SST and water depth effects, we developed more accurate OH‐GDGT‐based paleothermometers for both shallow regions and the global ocean, encompassing the full‐ocean‐depth range. Our findings highlight the importance of accounting for the effect of water depth on OH‐GDGTs and provide improved tools for reconstructing paleo‐SSTs. Plain Language Summary Building quantitative proxies that can accurately estimate SSTs is one of the most common themes in paleoceanography. Archeal‐derived hydroxylated isoprenoid glycerol dialkyl glycerol tetraethers (OH‐GDGTs) preserved in marine sediments have a potential to reflect past sea surface temperatures (SSTs). However, the source organisms of OH‐GDGTs can live throughout the water column, implying that sedimentary OH‐GDGTs record an integrated water column signal rather than only SST. Currently, the effect of water depth on sedimentary OH‐GDGTs remains vague. We investigated the distribution of OH‐GDGTs in 13 sediment cores in the hadal zone, which represents the deepest and least explored habitats on Earth's surface. The data from this study and literature revealed that the deep‐sea (including hadal trench) sediments are characterized by a predominance of OH‐GDGT‐0, which causes a considerable underestimation of OH‐GDGT‐derived SSTs. We evaluated the effects of both SST and water depth on OH‐GDGTs and established new calibrations that more accurately reconstruct paleotemperatures at a global scale. Key Points Sedimentary hydroxylated isoprenoid glycerol dialkyl glycerol tetraethers (OH‐GDGTs) were first investigated in the Kermadec and Atacama trenches with water depth ranging from 2,560 to 9,560 m Water depth has large impact on OH‐GDGT distributions with higher OH‐GDGT‐0% and lower RI‐OH′ values of deep‐sea sediments More accurate global sea surface temperature calibrations based on OH‐GDGTs were established

The pathogenesis of Alzheimer's disease (AD) is closely linked to astrocytes. This study conducts a bibliometric analysis of data from a wide range of literature in this field to enhance the in-depth understanding of this area. Publications were retrieved from the 2000-2025 Web of Science Core Collection on January 21, 2025. Bibliometrix-package of R, VOSviewer and CiteSpace were used to visualize the research focus and trends. The number of citations for the top 100 articles ranged from 208 to 602 citations, with a median of 293 and an average of 331.67 citations per article. The author with the most contributions to this collection was Holtzman David M, who authored 7 papers. Most articles originated in the United States (  = 69), while Washington University was the institution with the most cited manuscripts (  = 40). The contributed the most publications (  = 15), followed by (  = 7). Co-occurrence of keywords analysis unveiled earlier studies focusing on \"messenger RNA,\" and \"IFN- ,\" recent studies concentrated on \"mechanisms,\" and \"activation.\" Moreover, keywords burst analysis indicated that the most recent prominent keywords were \"Aβ,\" \"activation\" and \"association\" since 2016. This is the first bibliometric analysis of the top 100 cited research on astrocytes and AD from 2000 to 2025, underscoring that the United States is a prominent leader in this field. Our analysis highlighted the growing interest in the pathogenesis of astrocytes in AD. Future studies on the mechanisms underlying astrocytes in AD will facilitate further research on new therapeutic approaches.

To improve the performance of the body‐in‐white (BIW) and achieve automotive lightweighting, a balanced approach across materials, techniques, and structures is required to save costs. This study describes an optimization approach for a partitioned carbon fiber composite floor based on composite material failure criteria, which employs a hybrid Particle Swarm Optimization (PSO) and Bacterial Foraging Optimization (BFO). A finite element model for the BIW was created and verified using simulation and experimental data. The steel middle floor was separated from the BIW model based on its stiffness, and static bending and torsion simulations were used to get stiffness information. The T700/WP‐R2300 composite material's characteristics were determined by quasi‐static mechanical testing. The middle floor was optimized using free‐size optimization, dimension optimization, and a ply stacking sequence design. The performance of the optimized carbon fiber composite floor was compared to a traditional steel floor. The results showed that the carbon fiber composite floor's bending stiffness rose by 74%, torsional stiffness by 46%, and weight was reduced by 46.7%. When combined with the BIW, the carbon fiber composite floor increased bending stiffness by 4.6%, torsional stiffness by 8.3%, and the initial bending and torsional frequencies by 8.8% and 7.4%, respectively, exhibiting considerable lightweighting effects. The PSO‐BFO‐optimized partitioned carbon fiber mid‐floor achieves a 46.7% weight reduction and significantly improves the bending and torsional stiffness and modal performance of the body‐in‐white.

Steel wire rope serves as a critical load-bearing and transmission component in the transportation equipment utilized in coal mines. It exhibits various forms of damage during prolonged service, which significantly jeopardizes the safety reliability of the transportation equipment. To investigate the formation process of the surface wear of steel wire rope and its influence on mechanical properties, the tribological evolution and performance degradation of the transmission wire rope under rope–sheave contact and rope–rope contact were studied in this paper. The wire rope’s friction coefficient (COF) is stable between 0.7 and 0.8 under two contact conditions. It is more likely to lead to the accumulation of frictional heat under the condition of rope–sheave contact. The primary wear mechanisms of transmission wire ropes are adhesive wear and fatigue wear. Additionally, the wear evolution leads to the nonlinear degradation of the tensile strength and bending fatigue life of the wire rope, and the wear damage caused by rope–sheave contact is more harmful. As the sliding distance between the wire rope and the sheave increases, the breaking force decreases from approximately 48 kN to 23 kN, and the number of bending fatigues of the wire rope before scrapping is reduced from approximately 6200 times to 200 times.

Black carbon is ubiquitous in the marine environment. However, whether it accumulates in the deepest ocean region, the hadal zone, is unknown. Here we measure the concentration and carbon isotopes (δ 13 C and Δ 14 C) of black carbon and total organic carbon in sediments from six hadal trenches. Black carbon constituted 10% of trench total organic carbon, and its δ 13 C and Δ 14 C were more negative than those of total organic carbon, suggesting that the black carbon was predominantly derived from terrestrial C3 plants and fossil fuels. The contribution of fossil carbon to the black carbon pool was spatially heterogeneous, which could be related to differences in the distance to landmass, land cover and socioeconomic development. Globally, we estimate a black carbon burial rate of 1.0 ± 0.5 Tg yr −1 in the hadal zone, which is seven-fold higher than the global ocean average per unit area. We propose that the hadal zone is an important, but overlooked, sink of black carbon in the ocean.

Objectives To analyze the diagnostic value of the tonsil–oropharynx (T/O) ratio on lateral cephalograms for evaluating tonsillar hypertrophy (TH). Methods A cross-sectional study was performed on 185 consecutive children (101 males, 84 females; mean age 7.3 ± 1.4 years) seeking orthodontic treatment. The T/O ratios on lateral cephalograms were calculated following Baroni et al.’s method. Tonsil sizes were clinically determined according to the Brodsky grading scale. Spearman correlation coefficients between the T/O ratio and clinical tonsil size were calculated with the total sample and subgroups and then compared between subgroups. Diagnostic value was analyzed using the receiver operating characteristic (ROC) curve, sensitivity, specificity, positive and negative predictive values, and accuracy. Results There was a strong correlation between the T/O ratio and clinical tonsil size in children (ρ = 0.73; P < 0.001). A significantly higher correlation coefficient was found in the Class III children. The ROC curve revealed an area under the curve of 0.90 (95% CI, 0.86–0.94; P < 0.001). The optimal cutoff value of the T/O ratio for predicting TH was 0.58, with a sensitivity of 98.7% and specificity of 64.2%. Employing the cutoff value of 0.5, the sensitivity was 100% and the specificity was 45.9%. Conclusions Measurement of the T/O ratio on lateral cephalograms may be helpful to initial screening in children for TH. Practitioners may combine the clinical examination of tonsil size with the cephalometric findings for a more comprehensive evaluation.