Chirality Effects in Peptide Assembly Structures

Peptide assembly structures have been widely exploited in fabricating biomaterials that are promising for medical applications. Peptides can self-organize into various highly ordered supramolecular architectures, such as nanofibril, nanobelt, nanotube, nanowire, and vesicle. Detailed studies of the molecular mechanism by which these versatile building blocks assemble can guide the design of peptide architectures with desired structure and functionality. It has been revealed that peptide assembly structures are highly sequence-dependent and sensitive to amino acid composition, the chirality of peptide and amino acid residues, and external factors, such as solvent, pH, and temperature. This mini-review focuses on the regulatory effects of chirality alteration on the structure and bioactivity of linear and cyclic peptide assemblies. In addition, chiral self-sorting and co-assembly of racemic peptide mixtures were discussed

Fabrication of micro/nanometer-channel by Near-Field ElectroSpinning

Direct-written polymer micro/nanofiber from Near- Field ElectroSpinning (NFES) was utilized as shadow-mask to fabricate uniform micro/nanometer-channel. Both Single straight microfiber (line-width 2~10?? m) and nanofiber (diameter 200~800nm) were direct-written on the substrate with the NFES setup, and then 2-nm-thick titanium adhesive layer and 10-nm- thick gold layer were sputtered on the substrate successively. By the ultrasonication process in acetone and de-ionized water, the polymer fiber was removed and micro/nanometer-channel with gap width ranging from 7?? m to 700nm was formed. The fabrication process and related technical issues were also outlined in this work. The experimental results revealed that the micro/nanometer channel had a good uniformity, above 90% of the gap length value lied within the deviation range of ±3%. This simple and facile method can be used to define the uniform micro/nano channel for organic thin film transistors. submicron-gap electrode by using an electrospun single fiber as shadow-mask. This is a simple and cost-effective method, yet the nanofiber used as shadow-mask was obtained through the post-stretching process, which increased the complexity and uncertainty of fabrication process. In this paper, Direct-write (DW) technology (9) based on Near-Field ElectroSpinning (NFES) (10) was utilized to obtain single straight micro/nanofiber directly, and used as shadow- mask to fabricate micro/nanometer-channel. The gap length of micro/nanometer-channel was in the range of 700nm to 7?? m. The fabrication process and related technical issues were described, and then the uniformity of micro/nanometer-channel was also evaluated and discussed

Bead-on-string structure formed by electrohydrodynamic printing

A Bead-on-String (B-S) structure which consists of droplet and filament is generated based on electrohydrodynamic printing system. The formation process of the B-S structure is demonstrated and discussed. Subsequently, the influence of the substrate moving speed on the B-S structure is investigated. The size of the droplet in the B-S structure decreases with the substrate moving speed. When the substrate moving speed is higher than the jetting speed, satellite droplet will appear and its number increases with the substrate moving speed. The effect of the solution concentration on the deposited patterns is also studied. A continuous line is printed with 3 wt% PEO solution. The B-S structure is generated when the concentration of the PEO solution is within 5-15 wt%. Moreover, the size of the droplet decreases with the increasing of the solution concentration. At the concentration of 18 wt%, nanofiber is produced and a pattern similar to the B-S structure is deposited on the substrate

Effect of Addition Groups on the Redox Properties of Fullerenes

采用循环伏安法和微分脉冲伏安法对比地研究了包括五种Ｃ６０的衍生物及四种Ｃ７０的衍生物的电化学性质．结果表明，推电子基团的引入使得富勒烯的氧化还原电位负移，这种负移的程度与加成基团的性质、个数和富勒烯的性质有关．对于Ｃ６０和Ｃ７０的单加成产物，负移的范围是０．０８～０．２０Ｖ．而对于Ｃ６０的双加成和三加成产物负移的范围分别为０．３０～０．３２Ｖ和０．５３～０．５８Ｖ．同时由于电位的负移大部分衍生物在低于＋１．５Ｖ（ｖｓ．ＳＣＥ）观察到了氧化峰，而Ｃ６０和Ｃ７０本身的氧化高达＋１．７Ｖ（ｖｓ．ＳＣＥ）．特别是对于Ｃ７０的双加成产物在＋０．４５Ｖ（ｖｓ．ＳＣＥ）出现了一个不可逆氧化峰，但是，对于同样加成基团的Ｃ６０双加成产物的氧化却在＋０．９０Ｖ（ｖｓ．ＳＣＥ），说明由于推电子基团的双加成引入，明显改变了Ｃ７０的电负性．Electrochemical properties of fullerene derivatives, including five C60 derivatives and four C70 derivatives, were studied systematically and comparatively by cyclic voltammetry and differential pulse wave voltammetry. The addition of the electrondonating groups on the fullerenes caused negative shift of the redox potentials of the fullerenes. The extent of the negative shift depends on the number and properties of the addition groups, and on the nature of the fullerenes. 0.08～0.20 V negative shift was observed for C60 and C70 monoadducts, 0.30～0.32 V for bisadduct and 0.53～0.58 V for triadduct of C60. Meanwhile, the oxidation waves of most of these derivatives appeared on their cyclic voltammograms. Particularly, an irreversible oxidation of the C70 bisadduct took place at +0.45 V (vs. SCE), while that of C60 bisadduct was at +0.90 V (vs. SCE), indicating that the electronegativity of C70 was greatly reduced by the bisaddition of the electrondonating groups.作者联系地址：中国科学院化学研究所Author's Address: Insti. of Chem., The Chinese Academy of Sinences, Beijing 10008

GPX8 regulates pan-apoptosis in gliomas to promote microglial migration and mediate immunotherapy responses

IntroductionGliomas have emerged as the predominant brain tumor type in recent decades, yet the exploration of non-apoptotic cell death regulated by the pan-optosome complex, known as pan-apoptosis, remains largely unexplored in this context. This study aims to illuminate the molecular properties of pan-apoptosis-related genes in glioma patients, classifying them and developing a signature using machine learning techniques.MethodsThe prognostic significance, mutation features, immunological characteristics, and pharmaceutical prediction performance of this signature were comprehensively investigated. Furthermore, GPX8, a gene of interest, was extensively examined for its prognostic value, immunological characteristics, medication prediction performance, and immunotherapy prediction potential. ResultsExperimental techniques such as CCK-8, Transwell, and EdU investigations revealed that GPX8 acts as a tumor accelerator in gliomas. At the single-cell RNA sequencing level, GPX8 appeared to facilitate cell contact between tumor cells and macrophages, potentially enhancing microglial migration. ConclusionsThe incorporation of pan-apoptosis-related features shows promising potential for clinical applications in predicting tumor progression and advancing immunotherapeutic strategies. However, further in vitro and in vivo investigations are necessary to validate the tumorigenic and immunogenic processes associated with GPX8 in gliomas

A Potential Synergy between Incomplete Arsenic Methylation Capacity and Demographic Characteristics on the Risk of Hypertension: Findings from a Cross-Sectional Study in an Arsenic-Endemic Area of Inner Mongolia, China

Inefficient arsenic methylation capacity has been associated with various health hazards induced by arsenic. In this study, we aimed to explore the interaction effect of lower arsenic methylation capacity with demographic characteristics on hypertension risk. A total of 512 adult participants (126 hypertension subjects and 386 non-hypertension subjects) residing in an arsenic-endemic area in Inner Mongolia, China were included. Urinary levels of inorganic arsenic (iAs), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) were measured for all subjects. The percentage of urinary arsenic metabolites (iAs%, MMA%, and DMA%), primary methylation index (PMI) and secondary methylation index (SMI) were calculated to assess arsenic methylation capacity of individuals. Results showed that participants carrying a lower methylation capacity, which is characterized by lower DMA% and SMI, have a higher risk of hypertension compared to their corresponding references after adjusting for multiple confounders. A potential synergy between poor arsenic methylation capacity (higher MMA%, lower DMA% and SMI) and older age or higher BMI were detected. The joint effects of higher MMA% and lower SMI with cigarette smoking also suggest some evidence of synergism. The findings of present study indicated that inefficient arsenic methylation capacity was associated with hypertension and the effect might be enhanced by certain demographic factors

Fabrication and Characterization of Electrospun Polycaprolactone Blended with Chitosan-Gelatin Complex Nanofibrous Mats

Design and fabrication of nanofibrous scaffolds should mimic the native extracellular matrix. This study is aimed at investigating electrospinning of polycaprolactone (PCL) blended with chitosan-gelatin complex. The morphologies were observed from scanning electron microscope. As-spun blended mats had thinner fibers than pure PCL. X-ray diffraction was used to analyze the degree of crystallinity. The intensity at two peaks at 2θ of 21° and 23.5° gradually decreased with the percentage of chitosan-gelatin complex increasing. Moreover, incorporation of the complex could obviously improve the hydrophilicity of as-spun blended mats. Mechanical properties of as-spun nanofibrous mats were also tested. The elongation at break of fibrous mats increased with the PCL content increasing and the ultimate tensile strength varied with different weight ratios. The as-spun mats had higher tensile strength when the weight ratio of PCL to CS-Gel was 75/25 compared to pure PCL. Both as-spun PCL scaffolds and PCL/CS-Gel scaffolds supported the proliferation of porcine iliac endothelial cells, and PCL/CS-Gel had better cell viability than pure PCL. Therefore, electrospun PCL/Chitosan-gelatin nanofibrous mats with weight ratio of 75/25 have better hydrophilicity mechanical properties, and cell proliferation and thus would be a promising candidate for tissue engineering scaffolds

Identification and temporal expression analysis of conserved and novel microRNAs in Sorghum

AbstractSweet Sorghum is largely grown for grain production but also recently emerged as one of the model feedstock plants for biofuel production. In plants, microRNA (miRNA)-guided gene regulation plays a key role in diverse biological processes, thus, their identification in different plant species is essential to understand post-transcriptional gene regulation. To identify miRNAs in Sorghum, we sequenced a small RNA library. Sequence analysis revealed the identity of 29 conserved miRNA families. Importantly, 13 novel miRNAs are identified, seven of which are conserved in closely related monocots. Temporal expression analysis of conserved and novel miRNAs indicated differential expression of several miRNAs. Approximately 125 genes that play diverse roles have been predicted as targets and a few targets were experimentally validated. These results provided insights into miRNA-controlled processes in Sorghum and also laid the foundation for manipulating miRNAs or their targets for improving biomass production and stress tolerance in Sorghum