Phosphorus-Doping Enables the Superior Durability of a Palladium Electrocatalyst towards Alkaline Oxygen Reduction Reactions.

The sluggish kinetics of oxygen reduction reactions (ORRs) require considerable Pd in the cathode, hindering the widespread of alkaline fuel cells (AFCs). By alloying Pd with transition metals, the oxygen reduction reaction's catalytic properties can be substantially enhanced. Nevertheless, the utilization of Pd-transition metal alloys in fuel cells is significantly constrained by their inadequate long-term durability due to the propensity of transition metals to leach. In this study, a nonmetallic doping strategy was devised and implemented to produce a Pd catalyst doped with P that exhibited exceptional durability towards ORRs. Pd3P0.95 with an average size of 6.41 nm was synthesized by the heat-treatment phosphorization of Pd nanoparticles followed by acid etching. After P-doping, the size of the Pd nanoparticles increased from 5.37 nm to 6.41 nm, and the initial mass activity (MA) of Pd3P0.95/NC reached 0.175 A mgPd-1 at 0.9 V, slightly lower than that of Pd/C. However, after 40,000 cycles of accelerated durability testing, instead of decreasing, the MA of Pd3P0.95/NC increased by 6.3% while the MA loss of Pd/C was 38.3%. The durability was primarily ascribed to the electronic structure effect and the aggregation resistance of the Pd nanoparticles. This research also establishes a foundation for the development of Pd-based ORR catalysts and offers a direction for the future advancement of catalysts designed for practical applications in AFCs.

Cell-type-specific effects of age and sex on human cortical neurons.

Altered transcriptional and epigenetic regulation of brain cell types may contribute to cognitive changes with advanced age. Using single-nucleus multi-omic DNA methylation and transcriptome sequencing (snmCT-seq) in frontal cortex from young adult and aged donors, we found widespread age- and sex-related variation in specific neuron types. The proportion of inhibitory SST- and VIP-expressing neurons was reduced in aged donors. Excitatory neurons had more profound age-related changes in their gene expression and DNA methylation than inhibitory cells. Hundreds of genes involved in synaptic activity, including EGR1, were less expressed in aged adults. Genes located in subtelomeric regions increased their expression with age and correlated with reduced telomere length. We further mapped cell-type-specific sex differences in gene expression and X-inactivation escape genes. Multi-omic single-nucleus epigenomes and transcriptomes provide new insight into the effects of age and sex on human neurons.

Recent Progress on Durable Metal-N-C Catalysts for Proton Exchange Membrane Fuel Cells.

It is essential for the widespread application of proton exchange membrane fuel cells (PEMFCs) to investigate low-cost, extremely active, and long-lasting oxygen reduction catalysts. Initial performance of PGM-free metal-nitrogen-carbon (M-N-C) catalysts for oxygen reduction reaction (ORR) has advanced significantly, particularly for Fe-N-C-based catalysts. However, the insufficient stability of M-N-C catalysts still impedes their use in practical fuel cells. In this review, we focus on the understanding of the structure-stability relationship of M-N-C ORR catalysts and summarize valuable guidance for the rational design of durable M-N-C catalysts. In the first section of this review, we discuss the inherent degrading mechanisms of M-N-C catalysts, such as carbon corrosion, demetallation, H2 O2 attack, etc. As we gain a thorough comprehension of these deterioration mechanisms, we shift our attention to the investigation of strategies that can mitigate catalyst deterioration and increase its stability. These strategies include enhancing the anti-oxidation of carbon, fortifying M-N bonds, and maximizing the effectiveness of free radical scavengers. This review offers a prospective view on the enhancement of the stability of non-noble metal catalysts.

Enantioselective Synthesis of Axially Chiral Diaryl Ethers via NHC Catalyzed Desymmetrization and Following Resolution.

Axially chiral diaryl ethers are present in numerous natural products and bioactive molecules. However, only few catalytic enantioselective approaches have been established to access diaryl ether atropisomers. Herein, we report the N-heterocyclic carbene-catalyzed enantioselective synthesis of axially chiral diaryl ethers via desymmetrization of prochiral 2-aryloxyisophthalaldehydes with aliphatic alcohols, phenol derivatives, and heteroaromatic amines. This reaction features mild reaction conditions, good functional group tolerance, broad substrate scope and excellent enantioselectivity. The utility of this methodology is illustrated by late-stage functionalization, gram-scale synthesis, and diverse enantioretentive transformations. Control experiments and DFT calculations support the association of NHC-catalyzed desymmetrization with following kinetic resolution to enhance the enantioselectivity.

Single-cell DNA methylome and 3D multi-omic atlas of the adult mouse brain.

Cytosine DNA methylation is essential in brain development and is implicated in various neurological disorders. Understanding DNA methylation diversity across the entire brain in a spatial context is fundamental for a complete molecular atlas of brain cell types and their gene regulatory landscapes. Here we used single-nucleus methylome sequencing (snmC-seq3) and multi-omic sequencing (snm3C-seq)1 technologies to generate 301,626 methylomes and 176,003 chromatin conformation-methylome joint profiles from 117 dissected regions throughout the adult mouse brain. Using iterative clustering and integrating with companion whole-brain transcriptome and chromatin accessibility datasets, we constructed a methylation-based cell taxonomy with 4,673 cell groups and 274 cross-modality-annotated subclasses. We identified 2.6 million differentially methylated regions across the genome that represent potential gene regulation elements. Notably, we observed spatial cytosine methylation patterns on both genes and regulatory elements in cell types within and across brain regions. Brain-wide spatial transcriptomics data validated the association of spatial epigenetic diversity with transcription and improved the anatomical mapping of our epigenetic datasets. Furthermore, chromatin conformation diversities occurred in important neuronal genes and were highly associated with DNA methylation and transcription changes. Brain-wide cell-type comparisons enabled the construction of regulatory networks that incorporate transcription factors, regulatory elements and their potential downstream gene targets. Finally, intragenic DNA methylation and chromatin conformation patterns predicted alternative gene isoform expression observed in a whole-brain SMART-seq2 dataset. Our study establishes a brain-wide, single-cell DNA methylome and 3D multi-omic atlas and provides a valuable resource for comprehending the cellular-spatial and regulatory genome diversity of the mouse brain.

Psychological Resilience of Chinese College Students: A Cross-Sectional Study after the Deblocking of China's COVID-19 Pandemic Strategy.

Psychological resilience (PR) plays an important role in fortifying mental health during pandemics. This study aimed to examine the PR and its related factors of college students in China after the deblocking of the China's COVID-19 pandemic strategy. A total of 1100 college students from 15 universities participated in this cross-sectional survey by multi-stage stratified sampling. Data were collected by self-designed socio-demographic information, the family function assessment scale (APGAR), a general health questionnaire (GHQ-12), the general self-efficacy scale (GSES), and a psychological resilience scale. The average score of PR was 135.65 ± 18.54. Cluster analysis of PR scores showed that 24.9% of the college students had weak PR. The higher PR, the higher mental health status (r = 0.352, p < 0.05). Females had higher PR than males (OR = 0.550, 95% CI: 0.367-0.827). High self-efficacy was an independent protective factor of high PR (OR = 0.093, 95% CI: 0.059-0.145). Low family contact frequency, poor family function, and bad mental health status were the independent risk factors of high PR. In conclusion, the PR of Chinese college students were insufficient after the deblocking of China's COVID-19 pandemic strategy, indicating an improvement of PR should be put into practice immediately. Frequent monthly contact with family, family function, self-efficacy, mental health status, and gender were the influencing factors of PR, which provides an intervention strategy for the future.

Ketones from aldehydes via alkyl C(sp3)-H functionalization under photoredox cooperative NHC/palladium catalysis.

Direct synthesis of ketones from aldehydes features high atom- and step-economy. Yet, the coupling of aldehydes with unactivated alkyl C(sp3)-H remains challenging. Herein, we develop the synthesis of ketones from aldehydes via alkyl C(sp3)-H functionalization under photoredox cooperative NHC/Pd catalysis. The two-component reaction of iodomethylsilyl alkyl ether with aldehydes gave a variety of ß-, γ- and δ-silyloxylketones via 1,n-HAT (n = 5, 6, 7) of silylmethyl radicals to generate secondary or tertiary alkyl radicals and following coupling with ketyl radicals from aldehydes under photoredox NHC catalysis. The three-component reaction with the addition of styrenes gave the corresponding ε-hydroxylketones via the generation of benzylic radicals by the addition of alkyl radicals to styrenes and following coupling with ketyl radicals. This work demonstrates the generation of ketyl radical and alkyl radical under the photoredox cooperative NHC/Pd catalysis, and provides two and three component reactions for the synthesis of ketones from aldehydes with alkyl C(sp3)-H functionalization. The synthetic potential of this protocol was also further illustrated by the late-stage functionalization of natural products.

Monomicelle-Directed Engineering of Strained Carbon Nanoribbons as Oxygen Reduction Catalyst.

To date, precisely tailoring local active sites of well-defined earth-abundant metal-free carbon-based electrocatalysts for attractive electrocatalytic oxygen reduction reaction (ORR), remains challenging. Herein, the authors successfully introduce a strain effect on active C-C bonds adjacent to edged graphitic nitrogen (N), which raises appropriate spin-polarization and charge density of carbon active sites and kinetically favor the facilitation of O2 adsorption and the activation of O-containing intermediates. Thus, the constructed metal-free carbon nanoribbons (CNRs-C) with high-curved edges exhibit outstanding ORR activity with half-wave potentials of 0.78 and 0.9 V in 0.5 m H2 SO4 and 0.1 m KOH, respectively, overwhelming the planar one (0.52 and 0.81 V) and the N-doped carbon sheet (0.41 and 0.71 V). Especially in acidic media, the kinetic current density (Jk ) is 18 times higher than that of the planar one and the N-doped carbon sheet. Notably, these findings show the spin polarization of the asymmetric structure by introducing a strain effect on the C-C bonds for boosting ORR.

Single-cell DNA Methylome and 3D Multi-omic Atlas of the Adult Mouse Brain.

Cytosine DNA methylation is essential in brain development and has been implicated in various neurological disorders. A comprehensive understanding of DNA methylation diversity across the entire brain in the context of the brain's 3D spatial organization is essential for building a complete molecular atlas of brain cell types and understanding their gene regulatory landscapes. To this end, we employed optimized single-nucleus methylome (snmC-seq3) and multi-omic (snm3C-seq1) sequencing technologies to generate 301,626 methylomes and 176,003 chromatin conformation/methylome joint profiles from 117 dissected regions throughout the adult mouse brain. Using iterative clustering and integrating with companion whole-brain transcriptome and chromatin accessibility datasets, we constructed a methylation-based cell type taxonomy that contains 4,673 cell groups and 261 cross-modality-annotated subclasses. We identified millions of differentially methylated regions (DMRs) across the genome, representing potential gene regulation elements. Notably, we observed spatial cytosine methylation patterns on both genes and regulatory elements in cell types within and across brain regions. Brain-wide multiplexed error-robust fluorescence in situ hybridization (MERFISH2) data validated the association of this spatial epigenetic diversity with transcription and allowed the mapping of the DNA methylation and topology information into anatomical structures more precisely than our dissections. Furthermore, multi-scale chromatin conformation diversities occur in important neuronal genes, highly associated with DNA methylation and transcription changes. Brain-wide cell type comparison allowed us to build a regulatory model for each gene, linking transcription factors, DMRs, chromatin contacts, and downstream genes to establish regulatory networks. Finally, intragenic DNA methylation and chromatin conformation patterns predicted alternative gene isoform expression observed in a companion whole-brain SMART-seq3 dataset. Our study establishes the first brain-wide, single-cell resolution DNA methylome and 3D multi-omic atlas, providing an unparalleled resource for comprehending the mouse brain's cellular-spatial and regulatory genome diversity.

Highly Stable Pt-Based Oxygen Reduction Electrocatalysts toward Practical Fuel Cells: Progress and Perspectives.

The high cost and poor reliability of cathodic electrocatalysts for the oxygen reduction reaction (ORR), which requires significant amounts of expensive and scarce platinum, obstructs the broad applications of proton exchange membrane fuel cells (PEMFCs). The principles of ORR and the reasons for the poor stability of Pt-based catalysts are reviewed. Moreover, this paper discusses and categorizes the strategies for enhancing the stability of Pt-based catalysts in fuel cells. More importantly, it highlights the recent progress of Pt-based stability toward ORR, including surface-doping, intermetallic structures, 1D/2D structures, rational design of support, etc. Finally, for atomic-level in-depth information on ORR catalysts in fuel cells, potential perspectives are suggested, such as large-scale preparation, advanced interpretation techniques, and advanced simulation. This review aims to provide valuable insights into the fundamental science and technical engineering for practical Pt-based ORR electrocatalysts in fuel cells.

The Fully Mediating Role of Psychological Resilience between Self-Efficacy and Mental Health: Evidence from the Study of College Students during the COVID-19 Pandemic.

Student populations are susceptible to the COVID-19 pandemic and may easy develop mental health problems related to their immaturity of psychological development and fluctuation of mood. However, little has been known about the effects of the pandemic on college students and the associated influencing factors. This study aimed to explore the role of psychological resilience as a mediator between general self-efficacy and mental health. A cross-sectional survey was conducted with 480 Chinese college students from 12 universities in Hunan province of China. The participants responded anonymously to the Generalized Self-Efficacy Scale (GSES), the Chinese version of the Resilience Scale for College Students (RSCS), and the 12-item General Health Questionnaire (GHQ-12). Hierarchical linear regression and structural equation modeling were used in this study. The average of GSES and RSCS scores of college students were 25.00 ± 4.68 and 137.97 ± 15.50, which were at a medium level. The average score for the GHQ-12 was 1.59 ± 1.59, and 22.03% of the college students scored ≥ 3 on the GHQ-12, indicating that they were at risk of developing mental disorders. According to the analyses of mediation effect, psychological resilience played a fully mediating role in the relationship between general self-efficacy and mental health. In conclusion, Chinese college students were at high risk of developing mental disorders during the COVID-19 period. General self-efficacy was positively associated with psychological resilience, and psychological resilience played a fully mediating role in the relationship between general self-efficacy and mental health. Future studies and interventions should aim to promote psychological resilience and general self-efficacy.

Mental health resources and its equity in Central South of China: A case study of Hunan Province.

OBJECTIVES: Mental health resources are an important basis for coping with mental health services. The equity is an important index of a reasonable allocation of health resources. This study aims to evaluate the mental health resources and its equity allocation in Hunan Province, which is one of the typical central south areas of China, so as to provide reference for the development of mental health in China and other areas. METHODS: Data related to mental health resources was obtained from the Project of Mental Health Resources in Hunan Province, which was conducted by the Department of Hunan Mental Health Center in 2019. The Gini coefficient, the Theil index and other indicators were employed to quantitatively evaluate the equity of mental health resources' allocation. RESULTS: By the end of 2018, there were a total of 141 mental health institutions in Hunan Province of China, the bed density was 5.31 beds per 10,000 people, the ratio of doctors to nurses was 2.20, the number of outpatients of mental health institutions was 1288,047 per year. The mental health resources' allocation in terms of demographic dimension were in a preferred status with the Gini values all less than 0.3, and the Gini values for mental health resources`allocation in terms of geographical dimension ranged from 0.24 to 0.35. The Theil index for mental health allocation in terms of demographic dimension was lower than 0.05, and the Theil index for mental health allocation in terms of geographical dimension ranged from 0.04 to 0.11. CONCLUSIONS: The shortage of mental health resources is still the priority issue to be increased and optimized by policy-makers in Hunan in the future, especially the human resources. Moreover, the utilization of mental health resources was low though its equity was fair. Policy-makers need to consider the high utilization and geographical accessibility of health resources among different regions to ensure people in different regions could get access to available health services.

Single nucleus multi-omics identifies human cortical cell regulatory genome diversity.

Single-cell technologies measure unique cellular signatures but are typically limited to a single modality. Computational approaches allow the fusion of diverse single-cell data types, but their efficacy is difficult to validate in the absence of authentic multi-omic measurements. To comprehensively assess the molecular phenotypes of single cells, we devised single-nucleus methylcytosine, chromatin accessibility, and transcriptome sequencing (snmCAT-seq) and applied it to postmortem human frontal cortex tissue. We developed a cross-validation approach using multi-modal information to validate fine-grained cell types and assessed the effectiveness of computational data fusion methods. Correlation analysis in individual cells revealed distinct relations between methylation and gene expression. Our integrative approach enabled joint analyses of the methylome, transcriptome, chromatin accessibility, and conformation for 63 human cortical cell types. We reconstructed regulatory lineages for cortical cell populations and found specific enrichment of genetic risk for neuropsychiatric traits, enabling the prediction of cell types that are associated with diseases.

Study on the Failure Mechanism and Permeability Characteristics of Gas Containing Sandstone Intercalated Coal.

The deformation failure mechanism and permeability characteristics of loaded coal sandstone samples under triaxial stress loading were analyzed based on the experimental platform of the coal-rock fluid solid coupling triaxial servo system. The results show that the stress-strain curve of coal intercalated sandstone can be divided into five stages: compaction closure, elastic deformation, stable fracture expansion, unstable fracture expansion, and post-peak strain softening. With the increase of confining pressure, the peak strength and residual strength of the sample increase linearly with the confining pressure. The permeability of the sample decreases slowly with the increase of axial strain, increases rapidly after reaching the stage of unstable fracture propagation, and changes in "V" shape. The relationship between initial permeability and confining pressure can be fitted with exponential function. Based on the fracture volumetric strain model, the progressive failure mechanism of damage expansion of coal mixed sandstone is discussed. The fracture volume strain of each sample under different stress states is given, and the failure mode and crack distribution characteristics of the sample are obtained. The research results can provide reference for reasonable, safe, and efficient coal mining and gas disaster control.

Concave Pt-Zn Nanocubes with High-Index Faceted Pt Skin as Highly Efficient Oxygen Reduction Catalyst.

High dosage of expensive Pt to catalyze the sluggish oxygen reduction reaction (ORR) on the cathode severely impedes the commercialization of proton exchange membrane fuel cells. Therefore, it is urgent to cut down the Pt catalyst by efficiently improving the ORR activity while maintaining high durability. Herein, magic concave Pt-Zn nanocubes with high-index faceted Pt skin (Pt78 Zn22 ) are proposed for high-efficiency catalysis toward proton exchange membrane fuel cells. These unique structural features endow the Pt-skin Pt78 Zn22 /KB with a mass activity of 1.18 mA µgPt -1 and a specific activity of 3.64 mA cm-2 for the ORR at 0.9 V (vs RHE). Meanwhile, the H2 -O2 fuel cell assembled by this catalyst delivers an ultrahigh peak power density of ≈1449 mW cm-2 . Both experiments and theoretical calculations show that the electronic structure of the surface is adjusted, thereby shortening the length of the Pt-Pt bond and reducing the adsorption energy of OH*/O* on the Pt surface. This work demonstrates the synergistic effect of the oxidation-resistant metal Zn and the construction of Pt-rich surface engineering. Also, it guides the future development of catalysts for their practical applications in energy conversion technologies and beyond.

Evolution of Cu single atom catalysts to nanoclusters during CO2 reduction to CO.

We synthesized Cu single atoms embedded in a N-doped porous carbon catalyst with a high Faradaic efficiency of 93.5% at -0.50 V (vs. RHE) for CO2 reduction to CO. The evolution of Cu single-atom sites to nanoclusters of about 1 nm was observed after CO2 reduction at a potential lower than -0.30 V (vs. RHE). The DFT calculation indicates that Cu nanoclusters improve the CO2 activation and the adsorption of intermediate *COOH, thus exhibiting higher catalytic activity than CuNx sites. The structural instability observed in this study helps in understanding the actual active sites of Cu single atom catalysts for CO2 reduction.

Boosting Nitrogen Reduction to Ammonia on FeN4 Sites by Atomic Spin Regulation.

Understanding the relationship between the electronic state of active sites and N2 reduction reaction (NRR) performance is essential to explore efficient electrocatalysts. Herein, atomically dispersed Fe and Mo sites are designed and achieved in the form of well-defined FeN4 and MoN4 coordination in polyphthalocyanine (PPc) organic framework to investigate the influence of the spin state of FeN4 on NRR behavior. The neighboring MoN4 can regulate the spin state of Fe center in FeN4 from high-spin (dxy 2 dyz 1 dxz 1 d z 2 1 d x 2 - y 2 1 ) to medium-spin (dxy 2 dyz 2 dxz 1 d z 2 1 ), where the empty d orbitals and separate d electron favor the overlap of Fe 3d with the N 2p orbitals, more effectively activating N≡N triple bond. Theoretical modeling suggests that the NRR preferably takes place on FeN4 instead of MoN4 , and the transition of Fe spin state significantly lowers the energy barrier of the potential determining step, which is conducive to the first hydrogenation of N2 . As a result, FeMoPPc with medium-spin FeN4 exhibits 2.0 and 9.0 times higher Faradaic efficiency and 2.0 and 17.2 times higher NH3 yields for NRR than FePPc with high-spin FeN4 and MoPPc with MoN4 , respectively. These new insights may open up opportunities for exploiting efficient NRR electrocatalysts by atomically regulating the spin state of metal centers.

Researching on the compliance of epilepsy patients of the Phenobarbital Epilepsy Management Project in a rural area of China: A retrospective study.

ABSTRACT: The aim of this study was to explore the compliance of epilepsy patients in the Phenobarbital Epilepsy Management Project in a rural area of China and its influencing factors, so as to provide the basis for further strategies.A retrospective study researching on the compliance of epilepsy patients in the Phenobarbital Epilepsy Management Project of Rural China was conducted. The Nan County, Hunan Province as a typical rural China was selected as the study site. We collected the compliance and other relative factors from 2017 to 2019 though the Phenobarbital Epilepsy Management Project data system.The good compliance patients in the Phenobarbital Epilepsy Management Project in a rural area of China were 98.99% (393/397); only 4 cases had poor compliance. The factors affecting the compliance of epilepsy patients were "adverse reactions of digestive tract symptoms," "how the patient felt physically, mentally, or working and learning ability during this period," and "the ratio of the attack to the previous one."The rate of good compliance among the epilepsy patients in the Phenobarbital Epilepsy Management Project in a rural area of China was high. More attention to education, patients' psychology, and the curative effect of family members may improve the compliance of patients with epilepsy further.

Enantioselective Synthesis of Axially Chiral Benzothiophene/Benzofuran-Fused Biaryls by N-Heterocyclic Carbene Catalyzed Arene Formation.

Axially chiral biaryl scaffolds are prevalent in natural products, chiral ligands, and organocatalysts. However, N-heterocyclic carbene (NHC) catalyzed de novo construction of an aromatic ring with concomitant axial chirality induction for the synthesis of biaryl atropisomers is far less developed, and the efficient synthesis of axially chiral tetra-ortho-substituted biaryls remains an unsolved problem under NHC catalysis. Reported here is an NHC-catalyzed de novo synthesis of axially chiral benzothiophene/benzofuran-fused biaryls from enals and 2-benzyl-benzothiophene/benzofuran-3-carbaldehydes through a [2+4] annulation, decarboxylation, and oxidative aromatization cascade with central-to-axial chirality conversion. The developed method provides efficient and general access to novel axially chiral benzothiophene/benzofuran-fused biaryls in high enantioselectivities and works well for the synthesis of tetra-ortho-substituted biaryls.

Regulating Fe-spin state by atomically dispersed Mn-N in Fe-N-C catalysts with high oxygen reduction activity.

As low-cost electrocatalysts for oxygen reduction reaction applied to fuel cells and metal-air batteries, atomic-dispersed transition metal-nitrogen-carbon materials are emerging, but the genuine mechanism thereof is still arguable. Herein, by rational design and synthesis of dual-metal atomically dispersed Fe,Mn/N-C catalyst as model object, we unravel that the O2 reduction preferentially takes place on FeIII in the FeN4 /C system with intermediate spin state which possesses one eg electron (t2g4eg1) readily penetrating the antibonding π-orbital of oxygen. Both magnetic measurements and theoretical calculation reveal that the adjacent atomically dispersed Mn-N moieties can effectively activate the FeIII sites by both spin-state transition and electronic modulation, rendering the excellent ORR performances of Fe,Mn/N-C in both alkaline and acidic media (halfwave positionals are 0.928 V in 0.1 M KOH, and 0.804 V in 0.1 M HClO4), and good durability, which outperforms and has almost the same activity of commercial Pt/C, respectively. In addition, it presents a superior power density of 160.8 mW cm-2 and long-term durability in reversible zinc-air batteries. The work brings new insight into the oxygen reduction reaction process on the metal-nitrogen-carbon active sites, undoubtedly leading the exploration towards high effective low-cost non-precious catalysts.