Engineering single-atom Mn on nitrogen-doped carbon to regulate lithium-peroxide reaction kinetics for rechargeable lithium-oxygen batteries

Precision engineering of catalytic sites to guide more favorable pathways for Li_(2)O_(2) nucleation and decom-position represents an enticing kinetic strategy for mitigating overpotential,enhancing discharge capac-ity,and improving recycling stability of Li-O_(2) batteries.In this work,we employ metal-organic frameworks(MOFs)derivation and ion substitution strategies to construct atomically dispersed Mn-N_(4) moieties on hierarchical porous nitrogen-doped carbon(Mn SAs-NC)with the aim of reducing the over-potential and improving the cycling stability of Li-O_(2) batteries.The porous structure provides more chan-nels for mass transfer and exposes more highly active sites for electrocatalytic reactions,thus promoting the formation and decomposition of Li_(2)O_(2).The Li-O_(2) batteries with Mn SAs-NC cathode achieve lower overpotential,higher specific capacity(14290 mA h g^(-1) at 100 mAg^(-1)),and superior cycle stability(>100 cycles at 200 mA g^(-1))compared with the Mn NPs-NC and NC.Density functional theory(DFT)cal-culations reveal that the construction of Mn-N_(4) moiety tunes the charge distribution of the pyridinic N-rich vacancy and balances the affinity of the intermediates(LiO_(2) and Li_(2)O_(2)).The initial nucleation of Li_(2)O_(2) on Mn SAs-NC favors the O_(2)-→LiO_(2)→Li_(2)O_(2) surface-adsorption pathway,which mitigates the overpoten-tials of the oxygen reduction(ORR)and oxygen evolution reaction(OER).As a result,Mn SAs-NC with Mn-N_(4) moiety effectively facilitates the Li_(2)O_(2) nucleation and enables its reversible decomposition.This work establishes a methodology for constructing carbon-based electrocatalysts with high activity and selectivity for Li-O_(2)batteries.

Fabrication of Graphene/Cu Composite by Chemical Vapor Deposition and Effects of Graphene Layers on Resultant Electrical Conductivity

Graphene(Gr)has unique properties including high electrical conductivity;Thus,graphene/copper(Gr/Cu)composites have attracted increasing attention to replace traditional Cu for electrical applications. However,the problem of how to control graphene to form desired Gr/Cu composite is not well solved. This paper aims at exploring the best parameters for preparing graphene with different layers on Cu foil by chemical vapor deposition(CVD)method and studying the effects of different layers graphene on Gr/Cu composite’s electrical conductivity. Graphene grown on single-sided and double-sided copper was prepared for Gr/Cu and Gr/Cu/Gr composites. The resultant electrical conductivity of Gr/Cu composites increased with decreasing graphene layers and increasing graphene volume fraction. The Gr/Cu/Gr composite with monolayer graphene owns volume fraction of less than 0.002%,producing the best electrical conductivity up to59.8 ×10^(6)S/m,equivalent to 104.5% IACS and 105.3% pure Cu foil.

基于体细胞突变数据库筛选免疫原性结直肠癌高频新抗原的方法

结直肠癌是世界高发和高致死率的恶性肿瘤。靶向新抗原的免疫治疗已被证实可以诱导癌症患者肿瘤持续消退,但这些特异性新抗原,仅适用于个体精准治疗。随着大量的高频肿瘤基因突变被发现,这些与突变相关的高频新抗原可覆盖更多人群,具有较强的临床意义。然而目前结直肠癌中是否也存在高频新抗原仍不清楚。本研究利用来源于321个结直肠癌患者的体细胞突变数据库,联合1种标准过滤和7种预测算法,筛选并获得了25个基于中国人高频分型HLA-A^*1101限制性的高频新抗原,它们均具有高亲和力(IC50<50 nmol/L)和高呈递分值(>0.90);其中,除了阳性对照多肽KRAS_G12V8-16外,11个高频新抗原能够在体外诱导细胞毒性T淋巴细胞(cytotoxic T lymphocyte,CTL)分泌γ干扰素(interferon gamma,IFN-γ),证实具有免疫原性。选取免疫原性最强的新抗原C1orf170_S418G413-421及阳性对照多肽KRAS_G12V8-16体外刺激T细胞,利用流式细胞分选及单细胞转录组测序技术,获得其特异性CTL的免疫组库信息,所构建的TCR-T(T-cell receptor engineered T cell)能够识别新抗原并分泌细胞因子。以上结果表明,本研究开发了一种利用体细胞数据库预测并体外筛选验证具有免疫原性高频新抗原的方法,为结直肠癌及其他癌种的多肽、DC(dendritic cells)疫苗、TCR-like抗体、TCR-T等免疫治疗提供了重要的多肽靶点和TCR信息,具有实际的临床应用价值。

Functional characterization of novel NPRL3 mutations identified in three families with focal epilepsy

Focal epilepsy accounts for 60% of all forms of epilepsy, but the pathogenic mechanism is not well understood. In this study,three novel mutations in NPRL3(nitrogen permease regulator-like 3), c.937_945del, c.1514dup C and 6,706-bp genomic DNA(g DNA) deletion, were identified in three families with focal epilepsy by linkage analysis, whole exome sequencing(WES) and Sanger sequencing. NPRL3 protein is a component of the GATOR1 complex, a major inhibitor of m TOR signaling. These mutations led to truncation of the NPRL3 protein and hampered the binding between NPRL3 and DEPDC5, which is another component of the GATOR1 complex. Consequently, the mutant proteins enhanced m TOR signaling in cultured cells, possibly due to impaired inhibition of m TORC1 by GATOR1. Knockdown of nprl3 in Drosophila resulted in epilepsy-like behavior and abnormal synaptic development. Taken together, these findings expand the genotypic spectrum of NPRL3-associated focal epilepsy and provide further insight into how NPRL3 mutations lead to epilepsy.

A single-cell approach to engineer CD8+ T cells targeting cytomegalovirus

T lymphocytes are crucial for antiviral responses and provide a promising repertoire for potential therapies of viral diseases such as cytomegalovirus(CMV)infection1 and the ongoing COVID-19 pandemic caused by SARS-CoV-2.^(2) CMV-related diseases occur once the host immune system is impaired or lacks a protective repertoire of virus-specific T lymphocytes.3 Adoptive transfer of T-cell receptor(TCR)-engineered T cells(TCR-Ts)provides an encouraging alternative treatment option for patients with CMV reactivation.^(4) However,generating TCR-Ts requires the identification of epitope-specific and functional TCR pairs.Modern single-cell sequencing techniques open up the ability to unravel TCR repertoires,^(5 )which offers a potential opportunity to screen functional TCR pairs for TCR-T therapy.Here,we report an efficient approach that combines ex vivo CD8+T-cell stimulation with single-cell RNA and TCR V(D)J sequencing to identify CMV-specific TCRs for generating TCR-Ts.

Evaluation of dry specimen transport and processing time using an isothermal amplification high-risk human papillomavirus assay

Background:Dry specimen transport has shown equivalence to traditional liquid transport using a novel high-risk Human papillomavirus assay.Considering that dry transport might cross obstacles during cervical cancer screening in low and middle resource settings,this study was designed evaluate different processing time of dry specimen transport using the same isothermal amplification hrHPV assay.Methods:There were 564 women between the ages of 30–55 recruited from colposcopy clinic.For each patient,two endocervical samples were collected and placed into empty collection tubes by physician.Samples were stored at room temperature until analyzed for hrHPV using the AmpFire assay at two time points:2 days and 2 weeks.511 of the 564 participants with positive hrHPV were provided colposcopy exam and quadrant biopsy.Results:A total of 1128 endocervical samples from 564 patients were detected by the Ampfire assay.Good agreement was found between two time periods(Kappa
Standard error=0.67±0.04).Sensitivity(2days/2weeks)for CIN2t was 95.28%(95%CI:92.14%–98.42%)vs 90.57%(CI(86.65%–94.49%)and specificity(2days/2weeks)was 22.47%(CI 19.33%–25.61%)vs 28.15%(CI 24.23%–32.07%)respectively.The difference for Ampfire HPV detection in sensitivity for CIN2t for the two time periods was not significant(P=0.227),while the difference in specificity for CIN2t was significant(P=0.001).The difference in Ct values 29.23(CI 28.15–30.31)and 29.27(CI 28.19–30.35)between two time points was not significant(P?0.164).Conclusion:Processing dry brush specimens can be delayed up to 2 weeks.Using the AmpFire assay platform which supports cervical cancer prevention programs in low-to-middle-income countries(LMICs).

Flavor profile disclosure of Chinese steamed breads(CSBs)by sensomics approach

The sensomics approach was applied to elucidate the flavor profile of Chinese steamed breads(CSBs)fermented by different fresh and dry yeast,respectively.The quantitative descriptive analysis(QDA)led to the establishment of seven sensory attributes.Results noted that fresh yeast CSBs were characterized by milk,bouquet,sweet,and sour attributes,while the corresponding dry yeast CSBs exhibited wheat and yeast attributes.According to OAVs≥1,34 aroma-active chemicals were shown to be significant odorants.Isoamyl alcohol,2,3-butanediol,benzoic acid,acetoin,hexanal,and indole had a significant contribution to the different aroma profiles of dry and fresh yeast CSBs.The result of correlation analysis showed that 2,3-butanediol and benzoic acid were correlated with sweet,milk,and sour attributes,hexanal and indole were related to bouquet attribute,and acetoin was associated with flour.Further aroma recombination confirmed the contribution of these key components in flavor discrimination of CSBs.These results will provide guidance for the yeast-CSBs flavor evaluation,improvement,and quality control.