The rapid development of the internet and digital media has provided convenience while also posing a potential risk of steganography abuse.Identifying steganographer is essential in tracing secret information origins ...The rapid development of the internet and digital media has provided convenience while also posing a potential risk of steganography abuse.Identifying steganographer is essential in tracing secret information origins and preventing illicit covert communication online.Accurately discerning a steganographer from many normal users is challenging due to various factors,such as the complexity in obtaining the steganography algorithm,extracting highly separability features,and modeling the cover data.After extensive exploration,several methods have been proposed for steganographer identification.This paper presents a survey of existing studies.Firstly,we provide a concise introduction to the research background and outline the issue of steganographer identification.Secondly,we present fundamental concepts and techniques that establish a general framework for identifying steganographers.Within this framework,state-of-the-art methods are summarized from five key aspects:data acquisition,feature extraction,feature optimization,identification paradigm,and performance evaluation.Furthermore,theoretical and experimental analyses examine the advantages and limitations of these existing methods.Finally,the survey highlights outstanding issues in image steganographer identification that deserve further research.展开更多
Objective:To observe the status quo of patients’psychological distress,and to explore the effect of Internet+health education model(IHEM)on patients who experienced psychological distress during their first hemodialy...Objective:To observe the status quo of patients’psychological distress,and to explore the effect of Internet+health education model(IHEM)on patients who experienced psychological distress during their first hemodialysis treatment,with the goal of reducing their psychological distress and improving their quality of life.Methods:IHEM was conducted on 120 first-time hemodialysis patients for 3 months while a distress thermometer and a list of questionnaires were used to screen patients and provide corresponding psychological intervention.The incidence rate of psychological distress was analyzed statistically to explore the difference in psychological distress at various periods.Results:The incidence rate(score≥4)of psychological distress in first-time hemodialysis patients was 46.67%,and their distress was mainly rooted in physical,emotional,practical problems(economy,time,and energy),etc.Through IHEM,the psychological distress scores of the patients decreased to 3.29±1.02 at one month after their discharge,and the incidence rate was 32.14%;the psychological distress scores of the patients were 2.29±1.02 at 3 months after their discharge,and the incidence rate was 21.14%.The difference before and after the intervention was statistically significant(P<0.05).Conclusion:A psychological distress thermometer can timely detect the degree and causes of psychological distress among first-time hemodialysis patients,and the use of IHEM may significantly alleviate the psychological distress among hemodialysis patients.展开更多
Injury to the peripheral nerves can result in temporary or life-long neuronal dysfunction and subsequent economic or social disability. Acidic fibroblast growth factor(a FGF) promotes the growth and survival of neuron...Injury to the peripheral nerves can result in temporary or life-long neuronal dysfunction and subsequent economic or social disability. Acidic fibroblast growth factor(a FGF) promotes the growth and survival of neurons and is a possible treatment for peripheral nerve injury. Yet,the actual therapeutic utility of a FGF is limited by its short half-life and instability in vivo. In the present study,we prepared sulfated chitooligosaccharides(SCOS),which have heparinlike properties,to improve the bioactivity of a FGF. We investigated the protective effects of SCOS with or without a FGF on RSC96 cells exposed to Na2 S2 O4 hypoxia/reoxygenation injury. Cell viability was measured by MTT assay and cytotoxicity induced by Na2 S2 O4 was assessed by lactate dehydrogenase(LDH) release into the culture medium. Pretreatment with a FGF and SCOS dramatically decreased LDH release after injury compared to pretreatment with a FGF or SCOS alone. We subsequently prepared an a FGF/SCOS thermo-sensitive hydrogel with poloxamer and examined its effects in vivo. Paw withdrawal thresholds and thermal withdrawal latencies were measured in rats with sciatic nerve injury. Local injection of the a FGF/SCOS hydrogels(a FGF: 40,80 μg/kg) increased the efficiency of sciatic nerve repair compared to a FGF(80 μg/kg) hydrogel alone. Especially a FGF/SCOS thermo-sensitive hydrogel decreased paw withdrawal thresholds from 117.75 ± 8.38(g,4 d) to 65.74 ± 3.39(g,10 d),but a FGF alone group were 140.58 ± 27.54(g,4 d) to 89.12 ± 5.60(g,10 d)(a FGF dose was 80 μg/kg,P < 0.05,n = 8). The thermal withdrawal latencies decreased from 11.61 ± 2.26(s,4 d) to 2.37 ±0.67(s,10 d). However,a FGF alone group were from 17.69 ± 1.47(s,4 d) to4.65 ± 1.73(s,10 d)(P < 0.05,n = 8). Furthermore,the a FGF/SCOS hydrogels also exhibited good biocompatibility in mice. In summary,SCOS improved the protective effects of a FGF in RSC96 cells injured with Na2S2O4 and increased the efficiency of nerve repair and recovery of function in rats with sciatic nerve injury. These findings pave an avenue for the development of novel prophylactic and therapeutic strategies for peripheral nerve injury.展开更多
Viruses are important components of the human body.Growing evidence suggests that they are engaged in the physiology and disease status of the host.Even though the vaginal microbiome is involved in human papillomaviru...Viruses are important components of the human body.Growing evidence suggests that they are engaged in the physiology and disease status of the host.Even though the vaginal microbiome is involved in human papillomavirus(HPV)infection and cervical cancer(CC)progression,little is known about the role of the vaginal virome.In this pilot exploratory study,using unbiased viral metagenomics,we aim to investigate the vaginal eukaryotic virome in women with different levels of cervical lesions,and examine their associations with different cervical disease status.An altered eukaryotic virome was observed in women with different levels of lesions and Lactobacillus profiles.Anelloviruses and papillomaviruses are the most commonly detected eukaryotic viruses of the vaginal virome.Higher abundance and richness of anelloviruses and papillomaviruses were associated with lowgrade squamous intraepithelial lesion(LSIL)and CC.Besides,higher anellovirus abundance was also associated with lactobacillus-depleted microbiome profiles and bacterial community state(CST)type IV.Furthermore,increased correlations between Anelloviridae and Papillomaviridae occurred in the women with increased cervical disease severity level from LSIL to CC.These data suggest underlying interactions between different microbes as well as the host physiology.Higher abundance and diversity of both anelloviruses and papillomaviruses shared by LSIL and CC suggest that anellovirus may be used as a potential adjunct biomarker to predict the risk of HPV persistent infection and/or CC.Future studies need to focus on the clinical relevance of anellovirus abundance with cervical disease status,and the evaluation of their potential as a new adjunct biomarker for the prediction and prognoses of CC.展开更多
Background The rock cut slope(RCS)could cause damage to regional ecological functions and landscapes and requires recovery.Biological soil crusts(BSCs)are pioneer and dominant colonizers during the initial recovery st...Background The rock cut slope(RCS)could cause damage to regional ecological functions and landscapes and requires recovery.Biological soil crusts(BSCs)are pioneer and dominant colonizers during the initial recovery stage.To accelerate the natural recovery of RCS,the development process and influencing agents of BSC should be revealed.Thus,the area index of crevices(IR),BSC coverage(COV)and biomass(BM),soil weight(SW),and major soil nutrients[organic carbon(OC),total nitrogen(TN)and total phosphorus(TP)]content,collected from 164 quadrats on 13 RCSs in the mountainous area of west Sichuan Province,China,were measured,to explore the effect of crevice of RCS on BSC development.Results Soil OC,TN and TP on RCSs ranged from 18.61 to 123.03 g kg^(-1),0.96 to 6.02 g kg^(-1)and 0.52 to 2.46 g kg^(-1),respectively,and were approximately to or higher than those on natural slopes.The OC,TN and TP contents in soils elevated unsystematically with recovery time of RCSs.BSCs on RCS distributed along crevices generally and firstly.During the first 13 years of natural recovery,COV,BM and SW ranged from 6.5 to 28.2%,14.43 to 67.25 g m^(-2),and 127.69 to 1277.74 g m^(-2),respectively.COV,BM and SW increased linearly with IR on RCSs.The positive correlation between COV and BM and IR was insignificantly impacted by bedrock,slope aspect and altitude within the recovery time less than 13 years.COV and BM on RCSs increased significantly when the recovery time is more than 27 years.Conclusions Crevice on RCSs could be a major environmental factor which is conducive to BSC development and soil accumulation through creating a space for water and soil particle.Furthermore,with the increase of recovery time of RCSs,BSCs may grow and reach a stable state with the promotion of soil nutrients,plant growth and microbial activity.These results provide a development process of BSC that from inside to outside the crevices on RCSs.In the areas with stable rock strata and a low risk of geological disasters,purposeful improvement in crevice density on RCS may effectively accelerate BSC development.展开更多
Nanocrystalline ZrB2 film and nanocomposite Zr-B-O-N films were prepared by non-reactive as well as re- active magnetron sputtering techniques, respectively. By means of X-ray diffraction analysis, electron probe micr...Nanocrystalline ZrB2 film and nanocomposite Zr-B-O-N films were prepared by non-reactive as well as re- active magnetron sputtering techniques, respectively. By means of X-ray diffraction analysis, electron probe microanalysis, X-ray photoelectron spectroscopy, and scanning electron microscopy, the influence of nitrogen flow ratio on the film microstructure and characteristics were investigated systematically, including the depo- sition rate, chemical compositions, phase constituents, grain size, chemical bonding, as well as cross-sectional morphologies. Meanwhile, the hardness and adhesion of above films were also evaluated by micro-indentation method and a scratch tester. With increasing the nitrogen flow ratio, the deposition rate of above films de- creased approximately linearly, whereas the contents of N and O in the films increased gradually and tended to saturation. Moreover, the film microstructure was also altered gradually from a fine columnar microstructure to a featureless glass-structure. As the nitrogen flow ratio was 11.7%, the Zr-B-O-N film possessed an typical nanocomposite structure and presented good mechanical properties. During the process of reactive sputtering of metal borides, the introduction of nitrogen can show a pronounced suppression of columnar grain growth and strong nanocomposite structure forming ability.展开更多
The emergence of super-resolution(SR)fluorescence microscopy has rejuvenated the search for new cellular substructures.However,SR fluorescence microscopy achieves high contrast at the expense of a holistic view of the...The emergence of super-resolution(SR)fluorescence microscopy has rejuvenated the search for new cellular substructures.However,SR fluorescence microscopy achieves high contrast at the expense of a holistic view of the interacting partners and surrounding environment.Thus,we developed SR fluorescence-assisted diffraction computational tomography(SR-FACT),which combines label-free three-dimensional optical diffraction tomography(ODT)with two-dimensional fluorescence Hessian structured illumination microscopy.The ODT module is capable of resolving the mitochondria,lipid droplets,the nuclear membrane,chromosomes,the tubular endoplasmic reticulum,and lysosomes.Using dual-mode correlated live-cell imaging for a prolonged period of time,we observed novel subcellular structures named dark-vacuole bodies,the majority of which originate from densely populated perinuclear regions,and intensively interact with organelles such as the mitochondria and the nuclear membrane before ultimately collapsing into the plasma membrane.This work demonstrates the unique capabilities of SR-FACT,which suggests its wide applicability in cell biology in general.展开更多
A successful tissue regeneration is a very complex process that requires a precise coordination of many molecular,cellular and physiological events.One of the critical steps is to convert the injury signals into regen...A successful tissue regeneration is a very complex process that requires a precise coordination of many molecular,cellular and physiological events.One of the critical steps is to convert the injury signals into regeneration signals to initiate tissue regeneration.Although many efforts have been made to investigate the mechanisms triggering tissue regeneration,the fundamental questions remain unresolved.One of the major obstacles is that the injury and the initiation of regeneration are two highly coupled processes and hard to separate from one another.In this article,we review the major events occurring at the early injury/regeneration stage in a range of species,and discuss the possible common mechanisms during initiation of tissue regeneration.展开更多
Infiltration-in situ reaction synthesis of Cf/TiAl3 composite was investigated. The as-cast material was obtained by titanium particles, carbon fibers and pure aluminum. Titanium particles and carbon fibers were mixed...Infiltration-in situ reaction synthesis of Cf/TiAl3 composite was investigated. The as-cast material was obtained by titanium particles, carbon fibers and pure aluminum. Titanium particles and carbon fibers were mixed and pressed to form a preform firstly, and then molten pure aluminum was pressed into the preform, subsequently, cooled rapidly. In situ reaction samples were obtained by heating the as-cast material from 600 to 1000℃ for I h. The microstructural evolution of in situ reaction samples was analyzed by scanning electron microscopy and energy dispersive X-ray. In addition, the phase composition of products was inspected by X-ray diffraction. Experimental results showed that the dominant product of TiAl3 and a small amount of Al4C3 were formed at low temperature. While TiAl3 was not stable at high temperature, along with its decrease, TiC phase became favorable. In the final products, TiAl3, TiC and Al4C3 were detected. Thus, the in situ reaction for Ti-Al-C system composite proceeded a formed-decomposed-precipitated mechanism.展开更多
Despite the wide application of super-resolution(SR)microscopy in biological studies of cells,the technology is rarely used to monitor functional changes in live cells.By combining fast spinning disc-confocal structur...Despite the wide application of super-resolution(SR)microscopy in biological studies of cells,the technology is rarely used to monitor functional changes in live cells.By combining fast spinning disc-confocal structured illumination microscopy(SD-SIM)with loading of cytosolic fluorescent Ca2+indicators,we have developed an SR method for visualization of regional Ca2+dynamics and related cellular organelle morphology and dynamics,termed SR calcium lantern imaging.In COS-7 cells stimulated with ATP,we have identified various calcium macrodomains characterized by different types of Ca2+release from endoplasmic reticulum(ER)stores.Finally,we demonstrated various roles of mitochondria in mediating calcium signals from different sources;while mitochondria can globally potentiate the Ca2+entry associated with store release,mitochondria also locally control Ca2+release from the neighboring ER stores and assist in their refilling processes.展开更多
Objective:To study the relationship between sleep disturbances and symptoms in patients with Parkinson’s disease(PD).Methods:The Parkinson’s Disease Sleep Scale-Chinese Version(PDSS-CV)was used to evaluate the sleep...Objective:To study the relationship between sleep disturbances and symptoms in patients with Parkinson’s disease(PD).Methods:The Parkinson’s Disease Sleep Scale-Chinese Version(PDSS-CV)was used to evaluate the sleep disturbances of PD patients in a cross sectional study.The Unified Parkinson’s Disease Rating Scale(UPDRS)parts II-IV,and the Hoehn&Yahr(H&Y)stage were used to determine the level of motor function in PD and the severity of PD.The Spearman correlation and a multiple regression analysis were used to identify the relationship between sleep disturbances and symptoms of PD.The quantities derived from the UPDRS and the H&Y stage and disease duration were compared between groups of patients either with or without sleep disturbances identified by the PDSS.This study was conducted from December 2011 to March 2012 at the First Affiliated Hospital of Sun Yat-sen University,in Guangzhou.Results:A total of 136 PD patients were included in this study.The overall total PDSS score in PD patients was 107.58±23.35 points(range:30–146).There were significant differences in the disease duration,the H&Y stage,and the UPDRS section subscores between groups of patients either with or without sleep disturbances(Kruskal-Wallis Test,p<0.05).There were significant negative correlations between PDSS scores and the UPDRS subscores,the H&Y stage and the disease duration(Spearman correlation,p<0.05).The multiple regression analysis indicated that sleep disturbances identified by the PDSS were only associated with daily life activity,tremor intensity and clinical fluctuation(R2=0.22,F(3,132)=12.4,p<0.001).The correlations were also significant when the contribution of the other two factors was excluded using partial correlations.Conclusions:The level of daily life activity and the occurrences of tremor and clinical fluctuation are likely to be important factors that lead to PD patients’sleep disturbances.This study may elucidate an important clue for the relationship between sleep disturbances and PD symptoms.展开更多
基金supported by the National Key Research and Development Program of China(No.2022YFB3102900)the National Natural Science Foundation of China(Nos.62172435,62202495 and 62002103)+2 种基金Zhongyuan Science and Technology Innovation Leading Talent Project of China(No.214200510019)Key Research and Development Project of Henan Province(No.2211321200)the Natural Science Foundation of Henan Province(No.222300420058).
文摘The rapid development of the internet and digital media has provided convenience while also posing a potential risk of steganography abuse.Identifying steganographer is essential in tracing secret information origins and preventing illicit covert communication online.Accurately discerning a steganographer from many normal users is challenging due to various factors,such as the complexity in obtaining the steganography algorithm,extracting highly separability features,and modeling the cover data.After extensive exploration,several methods have been proposed for steganographer identification.This paper presents a survey of existing studies.Firstly,we provide a concise introduction to the research background and outline the issue of steganographer identification.Secondly,we present fundamental concepts and techniques that establish a general framework for identifying steganographers.Within this framework,state-of-the-art methods are summarized from five key aspects:data acquisition,feature extraction,feature optimization,identification paradigm,and performance evaluation.Furthermore,theoretical and experimental analyses examine the advantages and limitations of these existing methods.Finally,the survey highlights outstanding issues in image steganographer identification that deserve further research.
基金Baoding Science and Technology Plan Project(Grant number:2041ZF311)。
文摘Objective:To observe the status quo of patients’psychological distress,and to explore the effect of Internet+health education model(IHEM)on patients who experienced psychological distress during their first hemodialysis treatment,with the goal of reducing their psychological distress and improving their quality of life.Methods:IHEM was conducted on 120 first-time hemodialysis patients for 3 months while a distress thermometer and a list of questionnaires were used to screen patients and provide corresponding psychological intervention.The incidence rate of psychological distress was analyzed statistically to explore the difference in psychological distress at various periods.Results:The incidence rate(score≥4)of psychological distress in first-time hemodialysis patients was 46.67%,and their distress was mainly rooted in physical,emotional,practical problems(economy,time,and energy),etc.Through IHEM,the psychological distress scores of the patients decreased to 3.29±1.02 at one month after their discharge,and the incidence rate was 32.14%;the psychological distress scores of the patients were 2.29±1.02 at 3 months after their discharge,and the incidence rate was 21.14%.The difference before and after the intervention was statistically significant(P<0.05).Conclusion:A psychological distress thermometer can timely detect the degree and causes of psychological distress among first-time hemodialysis patients,and the use of IHEM may significantly alleviate the psychological distress among hemodialysis patients.
基金supported by the Science and Technology Program of Guangzhou (201508020001)the Major Scientific and Technological Special Project of the Administration of Ocean and Fisheries of Guangdong Province (Yuecainong, 2017, no. 17)+2 种基金the Operating fund of Guangdong Provincial Key Laboratory of Bioengineering Medicine (No. 2014B030301050)a project of the Research Development and Industrialization of Guangdong Province (2013B090500046)the Guangdong Province Higher Vocational Colleges and Schools Pearl River Scholar Funded Scheme (2012)
文摘Injury to the peripheral nerves can result in temporary or life-long neuronal dysfunction and subsequent economic or social disability. Acidic fibroblast growth factor(a FGF) promotes the growth and survival of neurons and is a possible treatment for peripheral nerve injury. Yet,the actual therapeutic utility of a FGF is limited by its short half-life and instability in vivo. In the present study,we prepared sulfated chitooligosaccharides(SCOS),which have heparinlike properties,to improve the bioactivity of a FGF. We investigated the protective effects of SCOS with or without a FGF on RSC96 cells exposed to Na2 S2 O4 hypoxia/reoxygenation injury. Cell viability was measured by MTT assay and cytotoxicity induced by Na2 S2 O4 was assessed by lactate dehydrogenase(LDH) release into the culture medium. Pretreatment with a FGF and SCOS dramatically decreased LDH release after injury compared to pretreatment with a FGF or SCOS alone. We subsequently prepared an a FGF/SCOS thermo-sensitive hydrogel with poloxamer and examined its effects in vivo. Paw withdrawal thresholds and thermal withdrawal latencies were measured in rats with sciatic nerve injury. Local injection of the a FGF/SCOS hydrogels(a FGF: 40,80 μg/kg) increased the efficiency of sciatic nerve repair compared to a FGF(80 μg/kg) hydrogel alone. Especially a FGF/SCOS thermo-sensitive hydrogel decreased paw withdrawal thresholds from 117.75 ± 8.38(g,4 d) to 65.74 ± 3.39(g,10 d),but a FGF alone group were 140.58 ± 27.54(g,4 d) to 89.12 ± 5.60(g,10 d)(a FGF dose was 80 μg/kg,P < 0.05,n = 8). The thermal withdrawal latencies decreased from 11.61 ± 2.26(s,4 d) to 2.37 ±0.67(s,10 d). However,a FGF alone group were from 17.69 ± 1.47(s,4 d) to4.65 ± 1.73(s,10 d)(P < 0.05,n = 8). Furthermore,the a FGF/SCOS hydrogels also exhibited good biocompatibility in mice. In summary,SCOS improved the protective effects of a FGF in RSC96 cells injured with Na2S2O4 and increased the efficiency of nerve repair and recovery of function in rats with sciatic nerve injury. These findings pave an avenue for the development of novel prophylactic and therapeutic strategies for peripheral nerve injury.
基金supported by the startup funding from Shanghai Public Health Clinical Center(to CZ).
文摘Viruses are important components of the human body.Growing evidence suggests that they are engaged in the physiology and disease status of the host.Even though the vaginal microbiome is involved in human papillomavirus(HPV)infection and cervical cancer(CC)progression,little is known about the role of the vaginal virome.In this pilot exploratory study,using unbiased viral metagenomics,we aim to investigate the vaginal eukaryotic virome in women with different levels of cervical lesions,and examine their associations with different cervical disease status.An altered eukaryotic virome was observed in women with different levels of lesions and Lactobacillus profiles.Anelloviruses and papillomaviruses are the most commonly detected eukaryotic viruses of the vaginal virome.Higher abundance and richness of anelloviruses and papillomaviruses were associated with lowgrade squamous intraepithelial lesion(LSIL)and CC.Besides,higher anellovirus abundance was also associated with lactobacillus-depleted microbiome profiles and bacterial community state(CST)type IV.Furthermore,increased correlations between Anelloviridae and Papillomaviridae occurred in the women with increased cervical disease severity level from LSIL to CC.These data suggest underlying interactions between different microbes as well as the host physiology.Higher abundance and diversity of both anelloviruses and papillomaviruses shared by LSIL and CC suggest that anellovirus may be used as a potential adjunct biomarker to predict the risk of HPV persistent infection and/or CC.Future studies need to focus on the clinical relevance of anellovirus abundance with cervical disease status,and the evaluation of their potential as a new adjunct biomarker for the prediction and prognoses of CC.
基金supported by the National Key Research and Development Programme of China(Grant No.2017YFC0504902)the Project of Assessment on Post-quake Ecosystem and Environment Recovery in Jiuzhaigou(Grant No.5132202020000046).
文摘Background The rock cut slope(RCS)could cause damage to regional ecological functions and landscapes and requires recovery.Biological soil crusts(BSCs)are pioneer and dominant colonizers during the initial recovery stage.To accelerate the natural recovery of RCS,the development process and influencing agents of BSC should be revealed.Thus,the area index of crevices(IR),BSC coverage(COV)and biomass(BM),soil weight(SW),and major soil nutrients[organic carbon(OC),total nitrogen(TN)and total phosphorus(TP)]content,collected from 164 quadrats on 13 RCSs in the mountainous area of west Sichuan Province,China,were measured,to explore the effect of crevice of RCS on BSC development.Results Soil OC,TN and TP on RCSs ranged from 18.61 to 123.03 g kg^(-1),0.96 to 6.02 g kg^(-1)and 0.52 to 2.46 g kg^(-1),respectively,and were approximately to or higher than those on natural slopes.The OC,TN and TP contents in soils elevated unsystematically with recovery time of RCSs.BSCs on RCS distributed along crevices generally and firstly.During the first 13 years of natural recovery,COV,BM and SW ranged from 6.5 to 28.2%,14.43 to 67.25 g m^(-2),and 127.69 to 1277.74 g m^(-2),respectively.COV,BM and SW increased linearly with IR on RCSs.The positive correlation between COV and BM and IR was insignificantly impacted by bedrock,slope aspect and altitude within the recovery time less than 13 years.COV and BM on RCSs increased significantly when the recovery time is more than 27 years.Conclusions Crevice on RCSs could be a major environmental factor which is conducive to BSC development and soil accumulation through creating a space for water and soil particle.Furthermore,with the increase of recovery time of RCSs,BSCs may grow and reach a stable state with the promotion of soil nutrients,plant growth and microbial activity.These results provide a development process of BSC that from inside to outside the crevices on RCSs.In the areas with stable rock strata and a low risk of geological disasters,purposeful improvement in crevice density on RCS may effectively accelerate BSC development.
基金funded the National Core Research Center(NCRC)Program through the National Research Foundation of Koreafunded by the Ministry of Education,Science and Technology(No.2012-0000-957)+1 种基金by the Fundamental R&D Program for Core Technology of Materials funded by the Ministry of Knowledge Economy,Republic of Koreafunded by the Shenyang Science&Technology Plan Project for the Special of Tackling Key Problems of Industrial Science and Technology(No.F12-012-2-00)
文摘Nanocrystalline ZrB2 film and nanocomposite Zr-B-O-N films were prepared by non-reactive as well as re- active magnetron sputtering techniques, respectively. By means of X-ray diffraction analysis, electron probe microanalysis, X-ray photoelectron spectroscopy, and scanning electron microscopy, the influence of nitrogen flow ratio on the film microstructure and characteristics were investigated systematically, including the depo- sition rate, chemical compositions, phase constituents, grain size, chemical bonding, as well as cross-sectional morphologies. Meanwhile, the hardness and adhesion of above films were also evaluated by micro-indentation method and a scratch tester. With increasing the nitrogen flow ratio, the deposition rate of above films de- creased approximately linearly, whereas the contents of N and O in the films increased gradually and tended to saturation. Moreover, the film microstructure was also altered gradually from a fine columnar microstructure to a featureless glass-structure. As the nitrogen flow ratio was 11.7%, the Zr-B-O-N film possessed an typical nanocomposite structure and presented good mechanical properties. During the process of reactive sputtering of metal borides, the introduction of nitrogen can show a pronounced suppression of columnar grain growth and strong nanocomposite structure forming ability.
基金supported by grants from the National Natural Science Foundation of China(91750203,91854112,81925022,31521062,91850111,31901061,and 31327901)the National Science and Technology Major Project Programme(2016YFA0500400,2017YFC0110203,and SQ2016YFJC040028)+3 种基金the Beijing Natural Science Foundation(L172003,7152079,and 5194026)the National Postdoctoral Program for Innovative Talents(BX201800008)the China Postdoctoral Science Foundation(2019M650329)the High-performance Computing Platform of Peking University.
文摘The emergence of super-resolution(SR)fluorescence microscopy has rejuvenated the search for new cellular substructures.However,SR fluorescence microscopy achieves high contrast at the expense of a holistic view of the interacting partners and surrounding environment.Thus,we developed SR fluorescence-assisted diffraction computational tomography(SR-FACT),which combines label-free three-dimensional optical diffraction tomography(ODT)with two-dimensional fluorescence Hessian structured illumination microscopy.The ODT module is capable of resolving the mitochondria,lipid droplets,the nuclear membrane,chromosomes,the tubular endoplasmic reticulum,and lysosomes.Using dual-mode correlated live-cell imaging for a prolonged period of time,we observed novel subcellular structures named dark-vacuole bodies,the majority of which originate from densely populated perinuclear regions,and intensively interact with organelles such as the mitochondria and the nuclear membrane before ultimately collapsing into the plasma membrane.This work demonstrates the unique capabilities of SR-FACT,which suggests its wide applicability in cell biology in general.
基金Ji-Feng Fei was supported by the National Key R&D Program of China 2019YFE0106700the Natural Science Foundation of China 31970782,Project of Department of Education of Guangdong Province 2018KZDXM027+1 种基金Key-Area Research and Development Program of Guangdong Province 2018B030332001,2019B030335001Yanmei Liu was supported by the Natural Science Foundation of China 32070819,91854112,91750203.
文摘A successful tissue regeneration is a very complex process that requires a precise coordination of many molecular,cellular and physiological events.One of the critical steps is to convert the injury signals into regeneration signals to initiate tissue regeneration.Although many efforts have been made to investigate the mechanisms triggering tissue regeneration,the fundamental questions remain unresolved.One of the major obstacles is that the injury and the initiation of regeneration are two highly coupled processes and hard to separate from one another.In this article,we review the major events occurring at the early injury/regeneration stage in a range of species,and discuss the possible common mechanisms during initiation of tissue regeneration.
文摘Infiltration-in situ reaction synthesis of Cf/TiAl3 composite was investigated. The as-cast material was obtained by titanium particles, carbon fibers and pure aluminum. Titanium particles and carbon fibers were mixed and pressed to form a preform firstly, and then molten pure aluminum was pressed into the preform, subsequently, cooled rapidly. In situ reaction samples were obtained by heating the as-cast material from 600 to 1000℃ for I h. The microstructural evolution of in situ reaction samples was analyzed by scanning electron microscopy and energy dispersive X-ray. In addition, the phase composition of products was inspected by X-ray diffraction. Experimental results showed that the dominant product of TiAl3 and a small amount of Al4C3 were formed at low temperature. While TiAl3 was not stable at high temperature, along with its decrease, TiC phase became favorable. In the final products, TiAl3, TiC and Al4C3 were detected. Thus, the in situ reaction for Ti-Al-C system composite proceeded a formed-decomposed-precipitated mechanism.
基金Supported by the grants from the National Science and Technology Major Project Program(2016YFA0500400)the National Natural Science Foundation of China(81925022,91854112,31327901,31521062,31570839,91750203)and Beijing Natural Science Foundation(L172003,7182063).
文摘Despite the wide application of super-resolution(SR)microscopy in biological studies of cells,the technology is rarely used to monitor functional changes in live cells.By combining fast spinning disc-confocal structured illumination microscopy(SD-SIM)with loading of cytosolic fluorescent Ca2+indicators,we have developed an SR method for visualization of regional Ca2+dynamics and related cellular organelle morphology and dynamics,termed SR calcium lantern imaging.In COS-7 cells stimulated with ATP,we have identified various calcium macrodomains characterized by different types of Ca2+release from endoplasmic reticulum(ER)stores.Finally,we demonstrated various roles of mitochondria in mediating calcium signals from different sources;while mitochondria can globally potentiate the Ca2+entry associated with store release,mitochondria also locally control Ca2+release from the neighboring ER stores and assist in their refilling processes.
基金This study was supported by grants from the Guangdong Natural Science Foundation(No.10151008901000187)the Guangdong Science and Technology Foundation(No.2010B080701107).
文摘Objective:To study the relationship between sleep disturbances and symptoms in patients with Parkinson’s disease(PD).Methods:The Parkinson’s Disease Sleep Scale-Chinese Version(PDSS-CV)was used to evaluate the sleep disturbances of PD patients in a cross sectional study.The Unified Parkinson’s Disease Rating Scale(UPDRS)parts II-IV,and the Hoehn&Yahr(H&Y)stage were used to determine the level of motor function in PD and the severity of PD.The Spearman correlation and a multiple regression analysis were used to identify the relationship between sleep disturbances and symptoms of PD.The quantities derived from the UPDRS and the H&Y stage and disease duration were compared between groups of patients either with or without sleep disturbances identified by the PDSS.This study was conducted from December 2011 to March 2012 at the First Affiliated Hospital of Sun Yat-sen University,in Guangzhou.Results:A total of 136 PD patients were included in this study.The overall total PDSS score in PD patients was 107.58±23.35 points(range:30–146).There were significant differences in the disease duration,the H&Y stage,and the UPDRS section subscores between groups of patients either with or without sleep disturbances(Kruskal-Wallis Test,p<0.05).There were significant negative correlations between PDSS scores and the UPDRS subscores,the H&Y stage and the disease duration(Spearman correlation,p<0.05).The multiple regression analysis indicated that sleep disturbances identified by the PDSS were only associated with daily life activity,tremor intensity and clinical fluctuation(R2=0.22,F(3,132)=12.4,p<0.001).The correlations were also significant when the contribution of the other two factors was excluded using partial correlations.Conclusions:The level of daily life activity and the occurrences of tremor and clinical fluctuation are likely to be important factors that lead to PD patients’sleep disturbances.This study may elucidate an important clue for the relationship between sleep disturbances and PD symptoms.
