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The electrocatalytic hydrogen evolution reaction (HER) is one of the most studied and promising processes for hydrogen fuel generation. Single-atom catalysts have been shown to exhibit ultra-high HER catalytic activity, but the harsh preparation conditions and the low single-atom loading hinder their practical applications. Furthermore, promoting hydrogen evolution reaction kinetics, especially in alkaline electrolytes, remains as an important challenge. Herein, Pt/C 60 catalysts with high-loading, high-dispersion single-atomic platinum anchored on C 60 are achieved through a room-temperature synthetic strategy. Pt/C 60 -2 exhibits high HER catalytic performance with a low overpotential (η 10 ) of 25 mV at 10 mA cm −2 . Density functional theory calculations reveal that the Pt-C 60 polymeric structures in Pt/C 60 -2 favors water adsorption, and the shell-like charge redistribution around the Pt-bonding region induced by the curved surfaces of two adjacent C 60 facilitates the desorption of hydrogen, thus favoring fast reaction kinetics for hydrogen evolution. The synthesis of high-loading Pt single-atom catalysts is important but challenging. Here, the authors use fullerene C 60 with electron-deficient C=C bonds to build Pt/C 60 catalysts with abundant Pt single atoms which exhibits high catalytic activity for electrochemical hydrogen evolution reactions

Background As a pervasive insect that transmits a variety of pathogens to humans and animals, the housefly has abundant and diverse microbial communities in its intestines. These gut microbes play an important role in the biology of insects and form a symbiotic relationship with the host insect. Alterations in the structure of the gut microbial community would affect larval development. Therefore, it is important to understand the mechanism regulating the influence of specific bacteria on the development of housefly larvae. Methods For this study we selected the intestinal symbiotic bacterium Enterobacter hormaechei , which is beneficial to the growth and development of housefly larvae, and used it as a probiotic supplement in larval feed. 16S rRNA gene sequencing technology was used to explore the effect of E. hormaechei  on the intestinal flora of housefly larvae, and plate confrontation experiments were performed to study the interaction between E. hormaechei and intestinal microorganisms. Results The composition of the gut microflora of the larvae changed after the larvae were fed E. hormaechei , with the abundance of Pseudochrobactrum ,  Enterobacter and Vagococcus  increasing and that of Klebsiella  and  Bacillus decreasing. Analysis of the structure and interaction of larval intestinal flora revealed that E. hormaechei inhibited the growth of harmful bacteria, such as Pseudomonas aeruginosa , Providencia stuartii and Providencia vermicola , and promoted the reproduction of beneficial bacteria. Conclusions Our study has explored the influence of specific beneficial bacteria on the intestinal flora of houseflies. The results of this study reveal the important role played by specific beneficial bacteria on the development of housefly larvae and provide insight for the development of sustained biological agents for housefly control through interference of gut microbiota. Graphical abstract

Culex pipiens pallens is an important vector of lymphatic filariasis and epidemic encephalitis. Mosquito control is the main strategy used for the prevention of mosquito-borne diseases. Bacillus thuringiensis israelensis ( Bti ) is an entomopathogenic bacterium widely used in mosquito control. In this study, we profiled the microbiota and transcriptional response of the larvae of Cx. pipiens pallens exposed to different concentrations of Bti . The results demonstrated that Bti induced a significant effect on both the microbiota and gene expression of Cx. pipiens pallens . Compared to the control group, the predominant bacteria changed from Actinobacteria to Firmicutes, and with increase in the concentration of Bti , the abundance of Actinobacteria was gradually reduced. Similar changes were also detected at the genus level, where Bacillus replaced Microbacterium , becoming the predominant genus in Bti -exposed groups. Furthermore, alpha diversity analysis indicated that Bti exposure changed the diversity of the microbota, possibly because the dysbiosis caused by the Bti infection inhibits some bacteria and provides opportunities to other opportunistic taxa. Pathway analysis revealed significant enhancement for processes associated with sphingolipid metabolism, glutathione metabolism and glycerophospholipid metabolism between all Bti- exposed groups and control group. Additionally, genes associated with the Toll and Imd signaling pathway were found to be notably upregulated. Bti infection significantly changed the bacterial community of larvae of Cx. pipiens pallens .

The ocean has experienced substantial oxygen loss over recent decades, affecting marine ecosystems and fisheries. Investigating ocean deoxygenation during hyperthermal events, such as the Paleocene-Eocene Thermal Maximum (PETM), offers insights into its future dynamics. Here, sediment cores from the South Atlantic reveal a pronounced decline in foraminifera-bound δ 15 N, concurrent with an increase in marine barite δ 34 S and enhanced ocean productivity during the PETM. These findings suggest an expansion of oxygen-deficient zones (ODZs) from suboxia to anoxia in the thermocline, with ammonium and sulfide accumulation. Model simulations indicate “ammonium-type” ODZs were driven by Southern Ocean warming and elevated productivity. Intense fixed nitrogen loss at the upper boundary of these ODZs, along with increased oceanic phosphorus inventory, likely spurred a compensatory rise in N 2 fixation. While the Pacific might experience different oxygenation conditions during the PETM, parts of the Atlantic thermocline became anoxic, highlighting potential spatial variabilities of ocean deoxygenation under global warming. Extreme warming 56 million years ago may have rendered parts of the subsurface Atlantic Ocean anoxic and toxic to fish due to ammonium and hydrogen sulfide accumulation – a scenario we must strive to prevent under current anthropogenic climate change.

Depressed adolescents often face challenges in resuming schooling, with gender differences and psychological factors influencing their intentions. This study aimed to investigate the mediating role of academic self-efficacy in the relationship between gender and the intention to resume schooling. Using convenience sampling, 295 school-suspended depressed adolescents (aged 12–18; mean age 15.84 ± 1.49; 75 males, 220 females) completed the General Situation Questionnaire, Questionnaire on the Intention to Resume Schooling, Kutcher Adolescent Depression Scale, and Academic Self-efficacy Questionnaire. Data were analyzed via SPSS 27.0.1 and R 4.4.3 software. Mediation analysis was performed using logistic regression modeling. The results showed that 42.70% (126/295) of participants intended to resume schooling. Gender disparities emerged in both intention to resume schooling (χ2 = 18.63, p < 0.001) and academic self-efficacy (Z = 2.31, p < 0.001) among depressed adolescents. Additionally, academic self-efficacy significantly differed across intention to resume schooling (Z = 3.05, p < 0.001). Gender differences in resumption intention were partially mediated by academic self-efficacy (effect = −0.18, 42.86% of total effect), with a direct gender effect of −0.24 (57.14%). These findings suggest that the gender of depressed adolescents not only directly affects their intention to resume schooling, but also indirectly affects their intention to resume schooling through academic self-efficacy.

Aedes albopictus originated in the tropical forests of Southeast Asia and can currently be found on all continents. As one of the main arboviral vectors, the control of Ae. albopictus requires novel strategies, informed by a deep knowledge of its biology. Little is known regarding mosquito long noncoding RNAs (lncRNAs), which are transcripts longer than 200 nucleotides that lack protein-coding potential and have roles in developmental regulation. Based on RNA-seq data from five developmental time points, eggs, early larvae, late larvae, pupae, and adults (female and male) of Ae. albopictus, 21,414 lncRNAs were characterized in this study. Differential expression analysis revealed that lncRNAs exhibited developmental stage specificity. The expression of most lncRNAs was upregulated at the onset of metamorphosis developmental stages. More differentially expressed lncRNAs were observed between eggs and early larvae. Weighted gene co-expression network analysis (WGCNA) further confirmed that the expression patterns of lncRNAs were obviously correlated with specific developmental time points. Functional annotation using co-expression analysis revealed that lncRNAs may be involved in the regulation of metamorphic developmental transitions of Ae. albopictus. The hub lncRNAs and hub gene clusters were identified for each module that were highly associated with specific developmental time points. The results of this study will facilitate future researches to elucidate the regulatory mechanisms of lncRNAs in the development of Ae. albopictus and utilize lncRNAs to assist with mosquito control.

The housefly larvae gut microbiota influences larval health and has become an important model to study the ecology and evolution of microbiota–host interactions. However, little is known about the phage community associated with the housefly larval gut, although bacteriophages are the most abundant members of the microbiota and have the potential to shape gut bacterial communities. Changes to bacteriophage composition are associated with disease, but how phages impact insect health remains unclear. We noticed that treating 1-day-old housefly larvae with ~10 7 , ~10 9 , and ~10 11 phage particles per ml of bacteriophages led to changes in the growth and development of housefly larvae. Additionally, treating housefly larvae with bacteriophages led to bacterial composition changes in the gut. Changes in the compositions of these gut bacteria are mainly manifested in the increase in harmful bacteria, including Pseudomonas and Providencia and the decrease in beneficial bacteria, including Enterobacter and Klebsiella , after different growth and development periods. The alterations in gut microbiota further influenced the larval growth and development. Collectively, these results indicate that bacteriophages can perturb the intestinal microbiome and impact insect health.

Background Aedes albopictus is a vector of numerous devastating arboviruses and places heavy burdens on global public health. Chitin is one of the important components of cuticles and targeting chitin metabolism is a promising strategy for preventing mosquito dispersal and mosquito-borne diseases. Increasing evidence suggests that microRNAs (miRNAs) play crucial roles in various physiological processes of insects. Methods A previous analysis suggested that the microRNA miR-989 is potentially involved in chitin metabolism in Ae. albopictus pupae. In the present study, we found that the expression level of miR-989 was significantly overexpressed after injection of agomir. A dual-luciferase assay was used to determine the direct target of miR-989. Survival rate, eclosion rate and malformation rate were statistically analyzed to evaluate the potential effect of miR-989. Hematoxylin–eosin staining and chitin staining were used to evaluate the microstructural changes in the cuticles of Ae. albopictus pupae. Results Overexpression of miR-989 resulted in a significantly reduced survival rate and eclosion rate of pupae and an elevated malformation rate of adults. The results suggested that miR-989 acted as a regulator of chitin metabolism in Ae. albopictus pupae by affecting the transcript levels of the Ae. albopictus genes encoding chitin synthase 1 ( AaCHS 1) and chitinase 10 ( AaCht 10). The altered expression levels of the two chitin metabolism-related enzymes (CHS1 and Cht10, respectively) caused the structural changes in cuticles and further affected the pupal-adult transition process of Ae. albopictus . XM_029863591.1 was proven to be the target gene of miR-989 and displayed similar effects on pupae as miR-989. Conclusions The microRNA miR-989 was found to be essential for chitin metabolism in old and new cuticles of Ae. albopictus pupae. The results of the current study suggested that miR-989 could be used as a potential target to control Ae . albopictus . Graphical Abstract

Background Air pollution has become a substantial environmental issue affecting human health and health-related behavior in China. Physical activity is widely accepted as a method to promote health and well-being and is potentially influenced by air pollution. Previous population-based studies have focused on the impact of air pollution on physical activity in the U.S. using a cross-sectional survey method; however, few have examined the impact on middle income countries such as China using follow-up data. The purpose of this study is to examine the impact of ambient fine particulate matter (PM 2.5 ) air pollution on physical activity among freshmen students living in Beijing by use of follow-up data. Methods We conducted 4 follow-up health surveys on 3445 freshmen students from Tsinghua University from 2012 to 2013 and 2480 freshmen completed all 4 surveys. Linear individual fixed-effect regressions were performed based on repeated-measure physical activity-related health behaviors and ambient PM 2.5 concentrations among the follow-up participants. Results An increase in ambient PM 2.5 concentration by one standard deviation (44.72 μg/m 3 ) was associated with a reduction in 22.32 weekly minutes of vigorous physical activity (95% confidence interval [CI] = 24.88–19.77), a reduction in 10.63 weekly minutes of moderate physical activity (95% CI = 14.61–6.64), a reduction in 32.45 weekly minutes of moderate to vigorous physical activity (MVPA) (95% CI = 37.63–27.28), and a reduction in 226.14 weekly physical activity MET-minute scores (95% CI = 256.06–196.21). The impact of ambient PM 2.5 concentration on weekly total minutes of moderate physical activity tended to be greater among males than among females. Conclusions Ambient PM 2.5 air pollution significantly discouraged physical activity among Chinese freshmen students living in Beijing. Future studies are warranted to replicate study findings in other Chinese cities and universities, and policy interventions are urgently needed to reduce air pollution levels in China.

Background Aedes albopictus is an increasingly serious threat in public health due to it is vector of multiple arboviruses that cause devastating human diseases, as well as its widening distribution in recent years. Insecticide resistance is a serious problem worldwide that limits the efficacy of chemical control strategies against Ae. albopictus . Chitinase genes have been widely recognized as attractive targets for the development of effective and environmentally safe insect management measures. Methods Chitinase genes of Ae . albopictus were identified and characterized on the basis of bioinformatics search of the referenced genome. Gene characterizations and phylogenetic relationships of chitinase genes were investigated, and spatio-temporal expression pattern of each chitinase gene was evaluated using qRT-PCR. RNA interference (RNAi) was used to suppress the expression of AaCht 10, and the roles of AaCht 10 were verified based on phynotype observations, chitin content analysis and hematoxylin and eosin (H&E) stain of epidermis and midgut. Results Altogether, 14 chitinase-related genes (12 chitinase genes and 2 IDGF s) encoding 17 proteins were identified. Phylogenetic analysis showed that all these AaCht s were classified into seven groups, and most of them were gathered into group IX. Only AaCht 5-1, AaCht 10 and AaCht 18 contained both catalytic and chitin-binding domains. Different AaCht s displayed development- and tissue-specific expression profiling. Suppression of the expression of AaCht 10 resulted in abnormal molting, increased mortality, decreased chitin content and thinning epicuticle, procuticle and midgut wall of pupa. Conclusions Findings of the present study will aid in determining the biological functions of AaCht s and also contribute to using AaCht s as potential target for mosquito management. Graphical Abstract