The esophagus is an important part of the human digestive system.Due to its limited regenerative capacity and the infeasibility of donor transplantation,esophageal replacement has become an important problem to be sol...The esophagus is an important part of the human digestive system.Due to its limited regenerative capacity and the infeasibility of donor transplantation,esophageal replacement has become an important problem to be solved urgently in clinics.In recent years,with the rapid development of tissue engineering technology in the biomedical field,tissue engineering stent(artificial esophagus)provides a new therapeutic approach for the repair and reconstruction of esophageal defects and has made remarkable progress.Biomedical esophageal stent materials have also experienced the development process from non-absorbable materials to absorbable materials,and then to new materials with composite cells and biological factors.In this paper,the composition,functional characteristics,and limitations of non-degradable scaffolds,biodegradable scaffolds,and Decellularized Matrix(DM)scaffolds specially designed for these applications are reviewed.Non-absorbable stents are typically composed of synthetic polymers or metals that provide structural support but fail to bind to surrounding tissues over time.In contrast,biodegradable stents are designed to break down gradually in the body while promoting cell infiltration and promoting new tissue formation.DM scaffolds can alleviate autoimmune reactions,preserve natural tissue characteristics,and enable recellularization during auto-repair.In addition,the significance of various cell-loaded materials in esophageal replacement has been explored,and the inclusion of cells in scaffold design has been shown to have the potential to enhance integration with host tissue and improve postoperative functional outcomes.These advances underscore ongoing efforts to closely mimic the structure of the natural esophagus.展开更多
大气细颗粒物(Atmospheric fine particulate matters,PMs)对人体健康产生的潜在危害已得到广泛关注。越来越多的研究表明,PMs暴露可产生呼吸、心血管系统等损伤影响,然而PMs是否可以进入大脑并产生神经毒性,一直是近年来大气雾霾健康...大气细颗粒物(Atmospheric fine particulate matters,PMs)对人体健康产生的潜在危害已得到广泛关注。越来越多的研究表明,PMs暴露可产生呼吸、心血管系统等损伤影响,然而PMs是否可以进入大脑并产生神经毒性,一直是近年来大气雾霾健康效应的重要研究方向。本文通过梳理现有流行病学研究证据以及体内外实验相关结果,讨论了PMs调控脑神经毒理学效应的潜在途径、不同生理阶段脑神经组织的损伤效应及其内在分子机理。据报道,大气PMs可通过血脑屏障途径和嗅觉神经途径和微生物群肠脑轴等影响神经系统。氧化应激、线粒体损伤、炎症、DNA损伤、表观遗传调节、血液稳态以及几个关键的信号通路被发现与大气PMs暴露引起的神经毒性有关。本文提出了进一步研究PMs神经毒理学效应,特别是针对特殊人群如儿童等神经发育的影响等方面研究的需求。在此基础上,本文指出了今后该领域的研究方向,为大气PMs的神经毒性和公共卫生危害的评价提供了理论依据。展开更多
Two methods, rapidly depressurizing to 0.1 MPa at a constant temperature and rising temperature under equilibrium P, T conditions, were used to study the dissociation of pure CH4 hydrate formed below the ice point. At...Two methods, rapidly depressurizing to 0.1 MPa at a constant temperature and rising temperature under equilibrium P, T conditions, were used to study the dissociation of pure CH4 hydrate formed below the ice point. At a constant temperature with rapidly depressurizing to 0.1 MPa, CH4 hydrate dissociated rapidly at initial dissociation and then the dissociation rate gradually decreased. However, the dissociation of CH4 hydrate at temperatures of 261 to 266 K was much faster than that at temperatures of 269 to 272 K, indicating its anomalous preservation. Under an equilibrium P, T conditions, rising temperature had extensively controlling impact on dissociation of CH4 hydrate at equilibrium pressures of 2.31, 2.16 and 1.96 MPa. In this study, we report the effect of pressure on CH4 hydrate dissociation, especially the effect of equilibrium pressure on dissociation at various melting temperatures. And we find that the ice particles size of CH4 hydrate formed may dominant the CH4 hydrate dissociation. Dissociation of CH4 hydrate formed from ice particles of smaller than 250 μm may not have an anomalous preservation below the ice point, while particles larger than 250 μm may have more extensive anomalous preservation.展开更多
To inhibit rapid capacity attenuation of Bi2Mn4O10 anode material in high-energy lithium-ion batteries,a novel high-purity anode composite material Bi2Mn4O10/ECP-N(ECP-N:N-doped Ketjen black)was prepared via an uncomp...To inhibit rapid capacity attenuation of Bi2Mn4O10 anode material in high-energy lithium-ion batteries,a novel high-purity anode composite material Bi2Mn4O10/ECP-N(ECP-N:N-doped Ketjen black)was prepared via an uncomplicated ball milling method.The as-synthesized Bi2Mn4O10/ECP-N composite demonstrated a great reversible specific capacity of 576.2 m A·h/g after 100 cycles at 0.2 C with a large capacity retention of 75%.However,the capacity retention of individual Bi2Mn4O10 was only 27%.Even at 3 C,a superior rate capacity of 236.1 m A·h/g was retained.Those remarkable electrochemical performances could give the credit to the introduction of ECP-N,which not only effectively improves the specific surface area to buffer volume expansion and enhances conductivity and wettability of composites but also accelerates the ion transfer and the reversible conversion reaction.展开更多
Cloud computing is very useful for big data owner who doesn't want to manage IT infrastructure and big data technique details. However, it is hard for big data owner to trust multi-layer outsourced big data system...Cloud computing is very useful for big data owner who doesn't want to manage IT infrastructure and big data technique details. However, it is hard for big data owner to trust multi-layer outsourced big data system in cloud environment and to verify which outsourced service leads to the problem. Similarly, the cloud service provider cannot simply trust the data computation applications. At last,the verification data itself may also leak the sensitive information from the cloud service provider and data owner. We propose a new three-level definition of the verification, threat model, corresponding trusted policies based on different roles for outsourced big data system in cloud. We also provide two policy enforcement methods for building trusted data computation environment by measuring both the Map Reduce application and its behaviors based on trusted computing and aspect-oriented programming. To prevent sensitive information leakage from verification process,we provide a privacy-preserved verification method. Finally, we implement the TPTVer, a Trusted third Party based Trusted Verifier as a proof of concept system. Our evaluation and analysis show that TPTVer can provide trusted verification for multi-layered outsourced big data system in the cloud with low overhead.展开更多
A novel ZnCo_2O_4/Bi_2O_3 heterojunction photocatalyst was prepared, and the formation of the heterojunction was confirmed via HRTEM. Photocatalytic activity of as-prepared samples was evaluated through photodegradati...A novel ZnCo_2O_4/Bi_2O_3 heterojunction photocatalyst was prepared, and the formation of the heterojunction was confirmed via HRTEM. Photocatalytic activity of as-prepared samples was evaluated through photodegradation of malachite green(MG). The degradation results show that the as-prepared13% ZnCo_2O_4/Bi_2O_3 heterojunction photocatalyst exhibits higher activity than pure Bi_2O_3. The MG degradation rate for the as-prepared catalyst is as high as 94%. The enhanced photocatalytic activity is mainly attributed to the broad photoabsorption and low recombination rate of photogenerated electronhole pairs, which is driven by the photogene rated potential difference formed at the ZnCo_2O_4/Bi_2O_3 heterojunction interface.展开更多
To investigate the behaviors of Cu^(2+)and Ni^(2+)with the change of conditions in Cu_(2+)−Ni_(2+)−NH_(3)−NH_(4)+−C_(2)O_(4)^(2-)−H_(2)O reaction system,mathematical models of thermodynamics based on the principle of ...To investigate the behaviors of Cu^(2+)and Ni^(2+)with the change of conditions in Cu_(2+)−Ni_(2+)−NH_(3)−NH_(4)+−C_(2)O_(4)^(2-)−H_(2)O reaction system,mathematical models of thermodynamics based on the principle of mass conservation were established.The simulation results indicate that the precipitation of metal ions from the aqueous phase is a complicated dynamic equilibrium process,during which the coordination reactions of Cu^(2+)and Ni^(2+)with NH3 forming[Cu(NH3)n]^(2+)(n=3−5)and[Ni(NH3)m]^(2+)(m=3−6)are predominant under high pH conditions,respectively.The pH ranges for the simultaneous precipitation of Cu^(2+)and Ni^(2+)are 2.0−6.5 and 2.0−5.5 when[NH3]T equals 0.6 and 4.2 mol/L,respectively,with the prefixed[C_(2)O_(4)^(2-)]T of 0.6 mol/L.Due to the fractional precipitation of Cu^(2+)and Ni^(2+),Cu−Ni composite is obtained after the thermal decomposition of Cu−Ni oxalate complex salts prepared in a pure water system when pH>7.0.By applying the mixed solvent(water/ethanol)as the precipitation medium,the Cu−Ni alloy rods can be finally fabricated with high purity and crystallinity.展开更多
The present study aims to further understanding of the principal reactions that occur during coal oxidation at moderate temperatures. Mass change and heat evolution of a sample were monitored by thermo-gravimetric ana...The present study aims to further understanding of the principal reactions that occur during coal oxidation at moderate temperatures. Mass change and heat evolution of a sample were monitored by thermo-gravimetric analysis coupled with differential thermal analysis (TGA/DTA). Gaseous and solid products were traced using online or in situ Fourier trans- form infrared spectroscopy (FTIR). Measurements were conducted by heating the samples up to 400?C, with the O2 concentration in the reaction medium set at 0, 10, 21, and 40 vol%, respectively. It was observed that the mass increase of a sample between 150?C and ~275oC was a result of the accumulation of C=O containing species in the coal structure, whereas substantial mass loss and heat evolution of a sample at ~400oC can be attributed to the significant involvement of the direct “burn-off” reaction. Enrichment of O2 inthe reaction medium leads to the acceleration in oxygen chemi- sorption, formation and decomposition of the solid oxygenated complexes, as well as the “burn-off” reaction. With the temperature increasing, the oxidation process governed by oxygen chemisorption gradually shifts to that by significant decomposition reactions, and eventually to that by the direct “burn-off” reaction. Temperature boundaries of these stages can be determined using parameters defined based on a set of TG/DTA data. Shift in the governing reactions is essentially due to the diverse requirements of reactants of the reactions and their energy barriers to be overcome. In en- gineering practice, the phenomena of self-heating and spontaneous combustion of coal correspond to chemisorption and the direct “burn-off” reaction, respectively.展开更多
The purpose of this study was to investigate the effects ofpolyelectrolyte multilayer （PEM） coatings on the biological behavior of titanium （Ti） substrates. Collagen type I/hyaluronic acid （Col/HA） and chitosan/...The purpose of this study was to investigate the effects ofpolyelectrolyte multilayer （PEM） coatings on the biological behavior of titanium （Ti） substrates. Collagen type I/hyaluronic acid （Col/HA） and chitosan/hyaluronic acid （Chi/HA） multilayer PEM coatings were introduced onto Ti substrates using layer-by-layer assembly. Contact angle instruments and quartz crystal microbalance were used for film characterization. The results obtained showed that both Col/HA and Chi/HA surfaces had high hydrophilicity and promoted cell adhesion in MC3T3-E1 pre-osteoblast and human gingival fibroblast cells. In addition, the synthesis of function-related proteins and gene expression levels in both MC3T3-E1 and fibroblast cells was higher for the Col/HA coating compared with the Chi/HA coating, indicating better cellular response to the Col/HA coating.展开更多
With the help of the redox mediator, decoupled water-splitting allows O_(2)and H_(2)to be produced at different times, at different rates, and even in different cells, which promotes both the operation safety and the ...With the help of the redox mediator, decoupled water-splitting allows O_(2)and H_(2)to be produced at different times, at different rates, and even in different cells, which promotes both the operation safety and the utilization of renewable power sources. However, the current densities and stabilities of these redox mediators are commonly low, which require further improvements for practical applications. Here, we propose to use supercapacitors as solid state redox mediators for decoupled water splitting. For demonstration, Na_(0.5)MnO_(2)(pseudocapacitor) and active carbon(double layer capacitor), are both used as the redox mediator. These supercapacitors show superior current density(1 A/cm^(2)) and ultralong cycle-life(8000 cycles) compared with commonly investigated battery-based mediators(NiOOH/Ni(OH)_(2)). Our research proves supercapacitors can be used as redox relay with high current density and stability, which may bring new insights in the design of decoupled water splitting systems.展开更多
Quasi-one-dimensional NiO with a hierarchically porous structure was synthesized through a facile coordination−precipitation method with the coupling effect of ammonia and a post-calcination treatment.The electrocatal...Quasi-one-dimensional NiO with a hierarchically porous structure was synthesized through a facile coordination−precipitation method with the coupling effect of ammonia and a post-calcination treatment.The electrocatalytic properties of NiO fibers for the oxidation of ethanol were compared with those of NiO spheres.The results show that the fibrous NiO possesses a larger specific surface area of 140.153 m2/g and a lower electrical resistivity of 4.5×105Ω·m,leading to an impressively superior electrocatalytic activity to spherical NiO for ethanol oxidation in alkaline media.The current decay on fibrous NiO at 0.6 V in 100−900 s was 0.00003%,which is much lower than that of spherical NiO,indicating its better stability.The unique morphology and hierarchically porous structure give the fibrous NiO great potential to be used as an anodic electrocatalyst for direct ethanol fuel cells.展开更多
Background:In vivo experiments were conducted to examine the effects of the targeted drug anlotinib on the stemness of hepatocellular carcinoma(HCC)cells and lenvatinib-resistant liver cancer cells and to explore the ...Background:In vivo experiments were conducted to examine the effects of the targeted drug anlotinib on the stemness of hepatocellular carcinoma(HCC)cells and lenvatinib-resistant liver cancer cells and to explore the underlying molecular mechanisms.Methods:A subcutaneous xenograft model of Hep3B-derived HCC was established in nude mice,which were randomly divided into 2 groups(n=5 males per group):(1)intragastric administration of anlotinib(0.4 mg/kg)and(2)intragastric administration of normal saline.We constructed lenvatinib-resistant cell lines and randomly divided the mice into 3 groups(n=5 males per group):(1)intragastric administration of anlotinib,(2)intragastric administration of lenvatinib,and(3)intragastric administration of normal saline.After 2 weeks of treatment,tumor tissues were harvested,and mRNA and proteins were isolated from the tissues.Changes in the expression of cancer stemness markers(epithelial cell adhesion molecule[EpCAM],CD13,CD90,aldehyde dehydrogenase 1[ALDH1],CD44,and CD45),totipotency factors(sex-determining region Y-box 2[Sox2],Nanog,octamer-binding transcription factor 4[Oct4]),and genes related to the Notch signaling pathway were examined.Results:Compared with that in the control group,tumor size and weight were reduced in nude mice treated with anlotinib.These differences were statistically significant in both the types of nude mice.Anlotinib affected stemness markers and totipotency factors by downregulating the expression of CD133,CD90,and G-protein–coupled receptor 5(LGR5)and upregulating the expression of intercellular adhesion molecule 1(ICAM-1)and Sox2.In addition,lenvatinib-resistant cell lines increased Notch signaling pathway,whereas anlotinib inhibited Notch signaling pathway.Conclusions:The antitumor effect of anlotinib on HCC and lenvatinib-resistant HCC cellsmay occur through inhibition of the Notch signaling pathway.Anlotinib may be the drug of choice for sequential therapy in lenvatinib-resistant liver cancer.展开更多
Background:Little is known about the association between venous thromboembolism(VTE)and tumors.In this study,we identified the clinical features of patients with liver cancer who presented with at least 1 VTE episode....Background:Little is known about the association between venous thromboembolism(VTE)and tumors.In this study,we identified the clinical features of patients with liver cancer who presented with at least 1 VTE episode.Methods:This was a retrospective case-control study of a single-institution database with univariate and multivariate analyses usingχ^(2)and Fisher exact tests.Statistical significance was set at P<0.05.Results:The overall incidence of VTE in the patients with liver cancer was 1.2%.More than half(53.8%)of the 13 patients with liver cancer and venous thrombosis died within 2 months.The thrombus in 12 patients(92.3%)was located within the deep veins,whereas the other patient(7.7%)was diagnosed with a pulmonary embolism.Of the 11 patients,9(69.2%)had swelling and/or pain symptoms.All 6 patients with peripherally inserted central catheters(PICCs)had thrombosis,accounting for 46.2%of all patients with liver cancer and venous thrombosis.Compared with the controls,liver cancer patients with PICC tubes,thrombosis-related symptoms such as swelling and pain,traumatic stimulation such as fracture,acute respiratory distress syndrome,and interventional therapy or hemostasis drugs were prone to be diagnosed with VTE(P<0.05).Conclusions:Liver cancer and thrombosis are rare and have poor prognoses.Liver cancer with thrombosis may be associated with PICC catheterization,traumatic stimulation,or hemostatic drugs.Patients with liver cancer and thrombosis often present with swelling and pain.展开更多
Objectives:This study aims to not only investigate the prevalence of social alienation among elderly patients undergoing radical prostatectomy for prostate cancer but also identify the contributing factors.Materials a...Objectives:This study aims to not only investigate the prevalence of social alienation among elderly patients undergoing radical prostatectomy for prostate cancer but also identify the contributing factors.Materials and methods:A total of 245 elderly patients diagnosed with prostate cancer and undergoing radical prostatectomy at a tertiary care general hospital in Jinan were included in this study.To assess the patients,several questionnaires were used.These included the General Situation Questionnaire,General Alienation Scale,Social Impact Scale,Modified Memorial Anxiety Scale for Prostate Cancer,and Perceived Social Support Scale.Pearson correlation analysis was conducted to examine the relationships between variables,whereas multiple linear regression was used to identify the factors influencing social alienation among patients who underwent radical prostatectomy.Results:Patients who underwent radical prostatectomy had a mean total score of 44.13±7.24 on the Social Alienation Scale.The results of the Pearson correlation analysis indicated that social alienation showed an inverse association with social support(r=−0.627,p<0.05)and positive associations with age,disease stigma,and anxiety(r=0.325,0.575,0.421,all p’s<0.01)among patients who underwent radical prostatectomy.The findings frommultiple linear regression analysis demonstrated that educational level,age,urinary incontinence,disease stigma,anxiety,and social support significantly influenced social alienation among elderly patients who underwent radical prostatectomy(p<0.05).Conclusions:Elderly patients who undergo radical prostatectomy often experience social alienation.This study found that social alienation was associated with factors such as educational level,age,urinary incontinence,social support,anxiety,and disease stigma.Consequently,healthcare providers should actively monitor the degree of social alienation in elderly patients after radical prostatectomy and provide suitable psychological care to facilitate positive social reintegration and alleviate their feelings of social alienation.展开更多
Traditional planar inductors in Radio Frequency （RF） Integrated Circuits （ICs） are plagued by large areas, low quality, and low frequencies. This paper describes a magnetic-based CMOS-compatible RF in- ductor. Mag...Traditional planar inductors in Radio Frequency （RF） Integrated Circuits （ICs） are plagued by large areas, low quality, and low frequencies. This paper describes a magnetic-based CMOS-compatible RF in- ductor. Magnetic-core inductors with various ferrite-filled structures, spiral structures, and magnetic material permeabilities were simulated to show that this inductor greatly improves the inductance by up to 97% and quality factor by 18.6% over a multi-GHz frequency range. The results indicate that the inductor is a very promising and viable solution to realize miniature, high quality, and high frequency on-chip inductors for high-end RF ICs.展开更多
基金supported by National Key R&D Program of China(No.2022YFE0138500)the Jilin Provincial Education Department Science Research Project(No.JJKH20231225KJ).
文摘The esophagus is an important part of the human digestive system.Due to its limited regenerative capacity and the infeasibility of donor transplantation,esophageal replacement has become an important problem to be solved urgently in clinics.In recent years,with the rapid development of tissue engineering technology in the biomedical field,tissue engineering stent(artificial esophagus)provides a new therapeutic approach for the repair and reconstruction of esophageal defects and has made remarkable progress.Biomedical esophageal stent materials have also experienced the development process from non-absorbable materials to absorbable materials,and then to new materials with composite cells and biological factors.In this paper,the composition,functional characteristics,and limitations of non-degradable scaffolds,biodegradable scaffolds,and Decellularized Matrix(DM)scaffolds specially designed for these applications are reviewed.Non-absorbable stents are typically composed of synthetic polymers or metals that provide structural support but fail to bind to surrounding tissues over time.In contrast,biodegradable stents are designed to break down gradually in the body while promoting cell infiltration and promoting new tissue formation.DM scaffolds can alleviate autoimmune reactions,preserve natural tissue characteristics,and enable recellularization during auto-repair.In addition,the significance of various cell-loaded materials in esophageal replacement has been explored,and the inclusion of cells in scaffold design has been shown to have the potential to enhance integration with host tissue and improve postoperative functional outcomes.These advances underscore ongoing efforts to closely mimic the structure of the natural esophagus.
文摘大气细颗粒物(Atmospheric fine particulate matters,PMs)对人体健康产生的潜在危害已得到广泛关注。越来越多的研究表明,PMs暴露可产生呼吸、心血管系统等损伤影响,然而PMs是否可以进入大脑并产生神经毒性,一直是近年来大气雾霾健康效应的重要研究方向。本文通过梳理现有流行病学研究证据以及体内外实验相关结果,讨论了PMs调控脑神经毒理学效应的潜在途径、不同生理阶段脑神经组织的损伤效应及其内在分子机理。据报道,大气PMs可通过血脑屏障途径和嗅觉神经途径和微生物群肠脑轴等影响神经系统。氧化应激、线粒体损伤、炎症、DNA损伤、表观遗传调节、血液稳态以及几个关键的信号通路被发现与大气PMs暴露引起的神经毒性有关。本文提出了进一步研究PMs神经毒理学效应,特别是针对特殊人群如儿童等神经发育的影响等方面研究的需求。在此基础上,本文指出了今后该领域的研究方向,为大气PMs的神经毒性和公共卫生危害的评价提供了理论依据。
基金supported by the Key Projector of Chinese Academy of Science (No. KZCX-YW-330)the National Science Fund Fostering Talents in Basic Research to Glaciology and Geocryology (Grant No. J0630966)
文摘Two methods, rapidly depressurizing to 0.1 MPa at a constant temperature and rising temperature under equilibrium P, T conditions, were used to study the dissociation of pure CH4 hydrate formed below the ice point. At a constant temperature with rapidly depressurizing to 0.1 MPa, CH4 hydrate dissociated rapidly at initial dissociation and then the dissociation rate gradually decreased. However, the dissociation of CH4 hydrate at temperatures of 261 to 266 K was much faster than that at temperatures of 269 to 272 K, indicating its anomalous preservation. Under an equilibrium P, T conditions, rising temperature had extensively controlling impact on dissociation of CH4 hydrate at equilibrium pressures of 2.31, 2.16 and 1.96 MPa. In this study, we report the effect of pressure on CH4 hydrate dissociation, especially the effect of equilibrium pressure on dissociation at various melting temperatures. And we find that the ice particles size of CH4 hydrate formed may dominant the CH4 hydrate dissociation. Dissociation of CH4 hydrate formed from ice particles of smaller than 250 μm may not have an anomalous preservation below the ice point, while particles larger than 250 μm may have more extensive anomalous preservation.
基金Project(2019zzts502)supported by the Fundamental Research Funds for the Central Universities of Central South University,ChinaProject(2018GK4001)supported by the Scientific and Technological Breakthrough and Major Achievements Transformation of Strategic Emerging Industries of Hunan Province,China。
文摘To inhibit rapid capacity attenuation of Bi2Mn4O10 anode material in high-energy lithium-ion batteries,a novel high-purity anode composite material Bi2Mn4O10/ECP-N(ECP-N:N-doped Ketjen black)was prepared via an uncomplicated ball milling method.The as-synthesized Bi2Mn4O10/ECP-N composite demonstrated a great reversible specific capacity of 576.2 m A·h/g after 100 cycles at 0.2 C with a large capacity retention of 75%.However,the capacity retention of individual Bi2Mn4O10 was only 27%.Even at 3 C,a superior rate capacity of 236.1 m A·h/g was retained.Those remarkable electrochemical performances could give the credit to the introduction of ECP-N,which not only effectively improves the specific surface area to buffer volume expansion and enhances conductivity and wettability of composites but also accelerates the ion transfer and the reversible conversion reaction.
基金partially supported by grants from the China 863 High-tech Program (Grant No. 2015AA016002)the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 20131103120001)+2 种基金the National Key Research and Development Program of China (Grant No. 2016YFB0800204)the National Science Foundation of China (No. 61502017)the Scientific Research Common Program of Beijing Municipal Commission of Education (KM201710005024)
文摘Cloud computing is very useful for big data owner who doesn't want to manage IT infrastructure and big data technique details. However, it is hard for big data owner to trust multi-layer outsourced big data system in cloud environment and to verify which outsourced service leads to the problem. Similarly, the cloud service provider cannot simply trust the data computation applications. At last,the verification data itself may also leak the sensitive information from the cloud service provider and data owner. We propose a new three-level definition of the verification, threat model, corresponding trusted policies based on different roles for outsourced big data system in cloud. We also provide two policy enforcement methods for building trusted data computation environment by measuring both the Map Reduce application and its behaviors based on trusted computing and aspect-oriented programming. To prevent sensitive information leakage from verification process,we provide a privacy-preserved verification method. Finally, we implement the TPTVer, a Trusted third Party based Trusted Verifier as a proof of concept system. Our evaluation and analysis show that TPTVer can provide trusted verification for multi-layered outsourced big data system in the cloud with low overhead.
基金financially supported by Jiana Foundation of Central South University(No.JNJJ201613)the National Natural Science Foundation of China(No.51404306)
文摘A novel ZnCo_2O_4/Bi_2O_3 heterojunction photocatalyst was prepared, and the formation of the heterojunction was confirmed via HRTEM. Photocatalytic activity of as-prepared samples was evaluated through photodegradation of malachite green(MG). The degradation results show that the as-prepared13% ZnCo_2O_4/Bi_2O_3 heterojunction photocatalyst exhibits higher activity than pure Bi_2O_3. The MG degradation rate for the as-prepared catalyst is as high as 94%. The enhanced photocatalytic activity is mainly attributed to the broad photoabsorption and low recombination rate of photogenerated electronhole pairs, which is driven by the photogene rated potential difference formed at the ZnCo_2O_4/Bi_2O_3 heterojunction interface.
基金the financial supports from Natural Science Foundation of Hunan Province,China(No.2020JJ4735)Science and Technology Department of Hunan Province Tackling Key Scientific and Technological Problems and Transformation of Major Scientific and Technological Achievements,China(No.2018GK4001)the Hunan Key Laboratory for Rare Earth Functional Materials,China(No.2017TP1031).
文摘To investigate the behaviors of Cu^(2+)and Ni^(2+)with the change of conditions in Cu_(2+)−Ni_(2+)−NH_(3)−NH_(4)+−C_(2)O_(4)^(2-)−H_(2)O reaction system,mathematical models of thermodynamics based on the principle of mass conservation were established.The simulation results indicate that the precipitation of metal ions from the aqueous phase is a complicated dynamic equilibrium process,during which the coordination reactions of Cu^(2+)and Ni^(2+)with NH3 forming[Cu(NH3)n]^(2+)(n=3−5)and[Ni(NH3)m]^(2+)(m=3−6)are predominant under high pH conditions,respectively.The pH ranges for the simultaneous precipitation of Cu^(2+)and Ni^(2+)are 2.0−6.5 and 2.0−5.5 when[NH3]T equals 0.6 and 4.2 mol/L,respectively,with the prefixed[C_(2)O_(4)^(2-)]T of 0.6 mol/L.Due to the fractional precipitation of Cu^(2+)and Ni^(2+),Cu−Ni composite is obtained after the thermal decomposition of Cu−Ni oxalate complex salts prepared in a pure water system when pH>7.0.By applying the mixed solvent(water/ethanol)as the precipitation medium,the Cu−Ni alloy rods can be finally fabricated with high purity and crystallinity.
基金supported by the National Natural Science Foundation of China(No.51974378)the Natural Science Foundation of Hunan province,China(No.2020JJ4735)the Hunan Key Laboratory for Rare Earth Functional Materials,China(No.2017TP1031).
文摘The present study aims to further understanding of the principal reactions that occur during coal oxidation at moderate temperatures. Mass change and heat evolution of a sample were monitored by thermo-gravimetric analysis coupled with differential thermal analysis (TGA/DTA). Gaseous and solid products were traced using online or in situ Fourier trans- form infrared spectroscopy (FTIR). Measurements were conducted by heating the samples up to 400?C, with the O2 concentration in the reaction medium set at 0, 10, 21, and 40 vol%, respectively. It was observed that the mass increase of a sample between 150?C and ~275oC was a result of the accumulation of C=O containing species in the coal structure, whereas substantial mass loss and heat evolution of a sample at ~400oC can be attributed to the significant involvement of the direct “burn-off” reaction. Enrichment of O2 inthe reaction medium leads to the acceleration in oxygen chemi- sorption, formation and decomposition of the solid oxygenated complexes, as well as the “burn-off” reaction. With the temperature increasing, the oxidation process governed by oxygen chemisorption gradually shifts to that by significant decomposition reactions, and eventually to that by the direct “burn-off” reaction. Temperature boundaries of these stages can be determined using parameters defined based on a set of TG/DTA data. Shift in the governing reactions is essentially due to the diverse requirements of reactants of the reactions and their energy barriers to be overcome. In en- gineering practice, the phenomena of self-heating and spontaneous combustion of coal correspond to chemisorption and the direct “burn-off” reaction, respectively.
基金financially supported by the National Natural Science Foundation of China (No. 51173163)the National Science-Technology Support Plan Project of China(No. 2012BAI07B01)the Fundamental Research Funds for Central Universities of China (No. 2012QNA7043)
文摘The purpose of this study was to investigate the effects ofpolyelectrolyte multilayer （PEM） coatings on the biological behavior of titanium （Ti） substrates. Collagen type I/hyaluronic acid （Col/HA） and chitosan/hyaluronic acid （Chi/HA） multilayer PEM coatings were introduced onto Ti substrates using layer-by-layer assembly. Contact angle instruments and quartz crystal microbalance were used for film characterization. The results obtained showed that both Col/HA and Chi/HA surfaces had high hydrophilicity and promoted cell adhesion in MC3T3-E1 pre-osteoblast and human gingival fibroblast cells. In addition, the synthesis of function-related proteins and gene expression levels in both MC3T3-E1 and fibroblast cells was higher for the Col/HA coating compared with the Chi/HA coating, indicating better cellular response to the Col/HA coating.
基金supported by the Shandong Provincial Natural Science Foundation, China (Nos. 2019GSF109029, ZR2021QB190)funded by the National Natural Science Foundation of China (Nos. 21771118, 21701098, 21875128 and 22109077)+1 种基金the Taishan Scholars Climbing Program of Shandong Province (No. tspd20150201)by the Yantai Double-hundred Talents Project。
文摘With the help of the redox mediator, decoupled water-splitting allows O_(2)and H_(2)to be produced at different times, at different rates, and even in different cells, which promotes both the operation safety and the utilization of renewable power sources. However, the current densities and stabilities of these redox mediators are commonly low, which require further improvements for practical applications. Here, we propose to use supercapacitors as solid state redox mediators for decoupled water splitting. For demonstration, Na_(0.5)MnO_(2)(pseudocapacitor) and active carbon(double layer capacitor), are both used as the redox mediator. These supercapacitors show superior current density(1 A/cm^(2)) and ultralong cycle-life(8000 cycles) compared with commonly investigated battery-based mediators(NiOOH/Ni(OH)_(2)). Our research proves supercapacitors can be used as redox relay with high current density and stability, which may bring new insights in the design of decoupled water splitting systems.
基金Project(51404306)supported by the National Natural Science Foundation of ChinaProject(JNJJ201613)supported by Jiana Foundation of Central South University,ChinaProject(2017YFC0210401)supported by the National Key Research and Development Program of China。
文摘Quasi-one-dimensional NiO with a hierarchically porous structure was synthesized through a facile coordination−precipitation method with the coupling effect of ammonia and a post-calcination treatment.The electrocatalytic properties of NiO fibers for the oxidation of ethanol were compared with those of NiO spheres.The results show that the fibrous NiO possesses a larger specific surface area of 140.153 m2/g and a lower electrical resistivity of 4.5×105Ω·m,leading to an impressively superior electrocatalytic activity to spherical NiO for ethanol oxidation in alkaline media.The current decay on fibrous NiO at 0.6 V in 100−900 s was 0.00003%,which is much lower than that of spherical NiO,indicating its better stability.The unique morphology and hierarchically porous structure give the fibrous NiO great potential to be used as an anodic electrocatalyst for direct ethanol fuel cells.
基金supported by the Natural Science Foundation of the Hubei Province(no.2023 AFB894)Open for the Key Laboratory of Biological Targeted Therapy in 2021(no.2021swbx019).
文摘Background:In vivo experiments were conducted to examine the effects of the targeted drug anlotinib on the stemness of hepatocellular carcinoma(HCC)cells and lenvatinib-resistant liver cancer cells and to explore the underlying molecular mechanisms.Methods:A subcutaneous xenograft model of Hep3B-derived HCC was established in nude mice,which were randomly divided into 2 groups(n=5 males per group):(1)intragastric administration of anlotinib(0.4 mg/kg)and(2)intragastric administration of normal saline.We constructed lenvatinib-resistant cell lines and randomly divided the mice into 3 groups(n=5 males per group):(1)intragastric administration of anlotinib,(2)intragastric administration of lenvatinib,and(3)intragastric administration of normal saline.After 2 weeks of treatment,tumor tissues were harvested,and mRNA and proteins were isolated from the tissues.Changes in the expression of cancer stemness markers(epithelial cell adhesion molecule[EpCAM],CD13,CD90,aldehyde dehydrogenase 1[ALDH1],CD44,and CD45),totipotency factors(sex-determining region Y-box 2[Sox2],Nanog,octamer-binding transcription factor 4[Oct4]),and genes related to the Notch signaling pathway were examined.Results:Compared with that in the control group,tumor size and weight were reduced in nude mice treated with anlotinib.These differences were statistically significant in both the types of nude mice.Anlotinib affected stemness markers and totipotency factors by downregulating the expression of CD133,CD90,and G-protein–coupled receptor 5(LGR5)and upregulating the expression of intercellular adhesion molecule 1(ICAM-1)and Sox2.In addition,lenvatinib-resistant cell lines increased Notch signaling pathway,whereas anlotinib inhibited Notch signaling pathway.Conclusions:The antitumor effect of anlotinib on HCC and lenvatinib-resistant HCC cellsmay occur through inhibition of the Notch signaling pathway.Anlotinib may be the drug of choice for sequential therapy in lenvatinib-resistant liver cancer.
基金approved by the Ethics Committee of Union Hospital,Huazhong University of Science and Technology,China(No.S810).
文摘Background:Little is known about the association between venous thromboembolism(VTE)and tumors.In this study,we identified the clinical features of patients with liver cancer who presented with at least 1 VTE episode.Methods:This was a retrospective case-control study of a single-institution database with univariate and multivariate analyses usingχ^(2)and Fisher exact tests.Statistical significance was set at P<0.05.Results:The overall incidence of VTE in the patients with liver cancer was 1.2%.More than half(53.8%)of the 13 patients with liver cancer and venous thrombosis died within 2 months.The thrombus in 12 patients(92.3%)was located within the deep veins,whereas the other patient(7.7%)was diagnosed with a pulmonary embolism.Of the 11 patients,9(69.2%)had swelling and/or pain symptoms.All 6 patients with peripherally inserted central catheters(PICCs)had thrombosis,accounting for 46.2%of all patients with liver cancer and venous thrombosis.Compared with the controls,liver cancer patients with PICC tubes,thrombosis-related symptoms such as swelling and pain,traumatic stimulation such as fracture,acute respiratory distress syndrome,and interventional therapy or hemostasis drugs were prone to be diagnosed with VTE(P<0.05).Conclusions:Liver cancer and thrombosis are rare and have poor prognoses.Liver cancer with thrombosis may be associated with PICC catheterization,traumatic stimulation,or hemostatic drugs.Patients with liver cancer and thrombosis often present with swelling and pain.
基金supported by the Shandong Provincial Nature Science Foundation(ZR2020QH240)the National Nature Science Foundation of China(NSFC82002719)the China Postdoctoral Science Foundation(2022 M711977).
文摘Objectives:This study aims to not only investigate the prevalence of social alienation among elderly patients undergoing radical prostatectomy for prostate cancer but also identify the contributing factors.Materials and methods:A total of 245 elderly patients diagnosed with prostate cancer and undergoing radical prostatectomy at a tertiary care general hospital in Jinan were included in this study.To assess the patients,several questionnaires were used.These included the General Situation Questionnaire,General Alienation Scale,Social Impact Scale,Modified Memorial Anxiety Scale for Prostate Cancer,and Perceived Social Support Scale.Pearson correlation analysis was conducted to examine the relationships between variables,whereas multiple linear regression was used to identify the factors influencing social alienation among patients who underwent radical prostatectomy.Results:Patients who underwent radical prostatectomy had a mean total score of 44.13±7.24 on the Social Alienation Scale.The results of the Pearson correlation analysis indicated that social alienation showed an inverse association with social support(r=−0.627,p<0.05)and positive associations with age,disease stigma,and anxiety(r=0.325,0.575,0.421,all p’s<0.01)among patients who underwent radical prostatectomy.The findings frommultiple linear regression analysis demonstrated that educational level,age,urinary incontinence,disease stigma,anxiety,and social support significantly influenced social alienation among elderly patients who underwent radical prostatectomy(p<0.05).Conclusions:Elderly patients who undergo radical prostatectomy often experience social alienation.This study found that social alienation was associated with factors such as educational level,age,urinary incontinence,social support,anxiety,and disease stigma.Consequently,healthcare providers should actively monitor the degree of social alienation in elderly patients after radical prostatectomy and provide suitable psychological care to facilitate positive social reintegration and alleviate their feelings of social alienation.
基金Supported by the National Natural Science Foundation of China(Nos. 61025021, 60936002, 60729308, 61011130296, and 61020106006)the National Key Projects of Science and Technology of China (No. 2009ZX02023-001-3)
文摘Traditional planar inductors in Radio Frequency （RF） Integrated Circuits （ICs） are plagued by large areas, low quality, and low frequencies. This paper describes a magnetic-based CMOS-compatible RF in- ductor. Magnetic-core inductors with various ferrite-filled structures, spiral structures, and magnetic material permeabilities were simulated to show that this inductor greatly improves the inductance by up to 97% and quality factor by 18.6% over a multi-GHz frequency range. The results indicate that the inductor is a very promising and viable solution to realize miniature, high quality, and high frequency on-chip inductors for high-end RF ICs.
