The severe erosion and inadequate mechanical strength are prominent challenges for high-energy gun propellants.To address it,novel PTW@PDA composites was prepared by polydopamine(PDA)-modifying onto potassium titanate...The severe erosion and inadequate mechanical strength are prominent challenges for high-energy gun propellants.To address it,novel PTW@PDA composites was prepared by polydopamine(PDA)-modifying onto potassium titanate whisker(PTW,K_(2)Ti_(6)O_(13)),and after was incorporated into gun propellant as erosion-reducing and mechanical-reinforcing fillers.The interfacial characterizations results indicated that as-prepared PTW@PDA composites exhibits an enhanced surface compatible with propellant matrix,thereby facilitating their dispersion into propellants more effectively than raw PTW materials.Compared to original propellants,PTW@PDA-modified propellants exhibited significant less erosion,with a Ti-Kbased protective coating being detected on the eroded steel.And 0.5 wt%and 1.0 wt%addition of PTW@PDA significantly improved impact,compressive and tensile strength of propellants.Despite the inevitably reduction in relative force,PTW@PDA slightly increase propellant burning rate while exerting little adverse impact on propellant dynamic activity.This strategy can provide a promising alternative to develop high-energy gun propellant with less erosion and more mechanical strength.展开更多
Hair loss and graying,the earliest visible signs of skin aging,are driven by the functional decline of hair follicle stem cells and their niches.To elucidate the transcriptional mechanisms involved in scalp aging,we c...Hair loss and graying,the earliest visible signs of skin aging,are driven by the functional decline of hair follicle stem cells and their niches.To elucidate the transcriptional mechanisms involved in scalp aging,we conducted a comprehensive analysis of human scalp samples using single-cell RNA sequencing and spatial transcriptomic technologies.Our study profiled the transcriptomes of 57,181 cells from scalp samples obtained from four young,six middle-aged,and one elderly individual.The integrated bioinformatic pipeline included cell clustering,spatial deconvolution,pseudotime trajectory,as well as cell-type specific gene expression,and intercellular communication analysis.An additional 92 volunteers were included,comprising 90(37 young,27 middle-aged,and 26 elderly)for trichoscopic examination,one young individual for senescence-associated β-galactosidase(SA-β-gal)staining,and one elderly individual for both MKI67 immunofluorescence and SA-β-gal staining.This approach led to several key findings:we identified three subtypes of mitotic keratinocytes that localized in the interfollicular epidermis(IFE),outer root sheath(ORS),and hair matrix,with pseudotime trajectory further confirming their transitional stage.Furthermore,in middleaged scalps,we observed activated activator protein 1(AP-1)transcription factor complex in keratinocytes,upregulated DCT gene in melanocytes,and decreased bone morphogenetic protein(BMP)and noncanonical wingless/integrated(ncWNT)signaling in dermal papilla(DP)-keratinocytes cross-talk.Due to the insufficient sample size and under-representation of elderly samples,transcriptional features associated with late aging,sex,and scalp regions were not completely captured.Nevertheless,our study provides valuable cell-resolved transcriptional insights into hair follicle aging and may support the development of future regenerative therapies.展开更多
基金the support of the instrument and equipment fund of the Key Laboratory of Special Energy,Ministry of Education,Nanjing University of Science and Technology,China.
文摘The severe erosion and inadequate mechanical strength are prominent challenges for high-energy gun propellants.To address it,novel PTW@PDA composites was prepared by polydopamine(PDA)-modifying onto potassium titanate whisker(PTW,K_(2)Ti_(6)O_(13)),and after was incorporated into gun propellant as erosion-reducing and mechanical-reinforcing fillers.The interfacial characterizations results indicated that as-prepared PTW@PDA composites exhibits an enhanced surface compatible with propellant matrix,thereby facilitating their dispersion into propellants more effectively than raw PTW materials.Compared to original propellants,PTW@PDA-modified propellants exhibited significant less erosion,with a Ti-Kbased protective coating being detected on the eroded steel.And 0.5 wt%and 1.0 wt%addition of PTW@PDA significantly improved impact,compressive and tensile strength of propellants.Despite the inevitably reduction in relative force,PTW@PDA slightly increase propellant burning rate while exerting little adverse impact on propellant dynamic activity.This strategy can provide a promising alternative to develop high-energy gun propellant with less erosion and more mechanical strength.
基金supported by the Science,Technology,and Innovation Commission of Shenzhen Municipality(grant number JCYJ20220818102809021 to F.X.).
文摘Hair loss and graying,the earliest visible signs of skin aging,are driven by the functional decline of hair follicle stem cells and their niches.To elucidate the transcriptional mechanisms involved in scalp aging,we conducted a comprehensive analysis of human scalp samples using single-cell RNA sequencing and spatial transcriptomic technologies.Our study profiled the transcriptomes of 57,181 cells from scalp samples obtained from four young,six middle-aged,and one elderly individual.The integrated bioinformatic pipeline included cell clustering,spatial deconvolution,pseudotime trajectory,as well as cell-type specific gene expression,and intercellular communication analysis.An additional 92 volunteers were included,comprising 90(37 young,27 middle-aged,and 26 elderly)for trichoscopic examination,one young individual for senescence-associated β-galactosidase(SA-β-gal)staining,and one elderly individual for both MKI67 immunofluorescence and SA-β-gal staining.This approach led to several key findings:we identified three subtypes of mitotic keratinocytes that localized in the interfollicular epidermis(IFE),outer root sheath(ORS),and hair matrix,with pseudotime trajectory further confirming their transitional stage.Furthermore,in middleaged scalps,we observed activated activator protein 1(AP-1)transcription factor complex in keratinocytes,upregulated DCT gene in melanocytes,and decreased bone morphogenetic protein(BMP)and noncanonical wingless/integrated(ncWNT)signaling in dermal papilla(DP)-keratinocytes cross-talk.Due to the insufficient sample size and under-representation of elderly samples,transcriptional features associated with late aging,sex,and scalp regions were not completely captured.Nevertheless,our study provides valuable cell-resolved transcriptional insights into hair follicle aging and may support the development of future regenerative therapies.
