Background:Hepatocellular carcinoma(HCC)appears to be strongly associated with immune-related genes.However,immune-related genes are not well understood as a prognostic marker in HCC caused by the hepatitis B virus(HB...Background:Hepatocellular carcinoma(HCC)appears to be strongly associated with immune-related genes.However,immune-related genes are not well understood as a prognostic marker in HCC caused by the hepatitis B virus(HBV).The purpose of this study was to investigate the prognostic significance of immune-related genes in HBV-infected HCC.Methods:Gene expression data from 114 HBV-infected HCC and 50 normal tissues were integrated into The Cancer Genome Atlas.Differentially expressed immune-associated genes were analyzed to identify immune-associated differential genes associated with overall survival.Least Absolute Shrinkage and Selection Operator and multivariate Cox regressions were used to constructing immunoprognostic models.An independent prognostic factor analysis using multiple Cox regressions was also performed for HBV-infected HCCs.Immunocorrelation analysis markers and immune cell infiltration were also investigated.Results:We found 113 differentially expressed immune-associated genes.Immune-related differential genes were significantly correlated with the overall survival of HCC patients.We constructed an immune-based prognostic model using multivariate Cox regression analysis including seven immune-related genes.According to further analysis,immune-related prognostic factors may serve as independent prognostic indicators in the clinical setting.There is also evidence that the 7-gene prognostic model reflects the tumor immune microenvironment as a result of the risk score model and immune cell infiltration.Conclusions:As a result of our study,we screened immune-related genes for prognosis in HBV-infected HCC and developed a novel immune-based prognostic model.The research not only provides new prognostic biomarkers but also offers insight into the tumor immune microenvironment and lays the theoretical groundwork for immunotherapy.展开更多
目的利用高分辨磁共振成像(high-resolution magnetic resonance imaging,HR-MRI)探究短暂性脑缺血发作(transient ischemic attack,TIA)频发组与非频发组间基底动脉管壁差异。材料与方法将经过头部三维时间飞跃法磁共振血管造影(three-...目的利用高分辨磁共振成像(high-resolution magnetic resonance imaging,HR-MRI)探究短暂性脑缺血发作(transient ischemic attack,TIA)频发组与非频发组间基底动脉管壁差异。材料与方法将经过头部三维时间飞跃法磁共振血管造影(three-dimension time of flight magnetic resonance angiography,3D-TOF-MRA)和基底动脉HR-MRI扫描后发现斑块的患者纳入研究。根据24 h内TIA频次分为频发组(≥2次)和非频发组(<2次)。对两组斑块形态学指标、狭窄程度、血管重构、斑块分布及临床特点进行分析。结果68例TIA患者,共184个斑块(频发组:38例、108个,非频发组:30例、76个)。最狭窄层面的斑块形态学指标组间差异均有统计学意义(P均<0.05)。频发组狭窄程度、重构指数较非频发组高,差异均有统计学意义(P均<0.05)。频发组腹侧斑块占比较大(38.0%vs 22.4%),背侧斑块占比较小(17.6%vs 35.5%),差异均有统计学意义(P=0.025、0.006);两组侧壁斑块比例(44.4%vs 42.1%)相似,差异无统计学意义(P=0.753)。两组临床因素差异均无统计学意义(P均>0.05)。结论频发组斑块多分布于腹侧,非频发组多分布于背侧,两组侧壁斑块比例相似。频发组斑块负荷、狭窄程度、重构指数更高,非频发组斑块更稳定。展开更多
Objective:Patients with cancer pain are highly dependent on morphine analgesia,but studies have shown a negative correlation between morphine demand and patient outcomes.The long-term use of morphine may result in abn...Objective:Patients with cancer pain are highly dependent on morphine analgesia,but studies have shown a negative correlation between morphine demand and patient outcomes.The long-term use of morphine may result in abnormally elevated serum morphine-3-glucuronide(M3G)levels.Hence,the effects of M3G on tumor progression are worth studying.Methods:The effects of M3G on PD-L1 expressions in human non-small cell lung cancer(NSCLC)cell lines were first evaluated.Activation of TLR4 downstream pathways after M3G treatment was then determined by Western blot.The effects of M3G on human cytotoxic T lymphocytes(CTL)cytotoxicity and INF-γrelease was also detected.Finally,the LLC murine lung adenocarcinoma cell line were used to establish a murine lung cancer model,and the effects of M3G on tumor growth and metastasis were determined.Results:M3G promoted the expressions of PD-L1 in the A549 and H1299 cell lines in a TLR4-dependent manner(P<0.05).M3G activated the PI3 K and the NFκB signaling pathways,and this effect was antagonized by a TLR4 pathway inhibitor.A PI3 K pathway inhibitor reversed the M3G-mediated PD-L1 upregulation.M3G inhibited the cytotoxicity of CTL on A549 cells and decreased the level of INF-γ.Repeated M3G intraperitoneal injections promoted LLC tumor growth and lung metastasis through the upregulation of tumor expressed PD-L1 and the reduction of CTL in the tumor microenvironment.Conclusions:M3G specifically activated TLR4 in NSCLC cells and upregulated PD-L1 expression through the PI3 K signaling pathway,thereby inhibiting CTL cytotoxicity and finally promoting tumor immune escape.展开更多
Myasthenia Gravis (MG) is an organ specific autoimmune disease mediated by autoantibodies (AChR Ab) against the acetylcholine receptor (AChR). Literature reported that the AChR Ab can be removed by absorbent linked w...Myasthenia Gravis (MG) is an organ specific autoimmune disease mediated by autoantibodies (AChR Ab) against the acetylcholine receptor (AChR). Literature reported that the AChR Ab can be removed by absorbent linked with tryptophan. It was studied in detail in our lab. With the aid of computer, we docked some ligands into AChR Ab, and the results from scores of docking under different generations showed that there was no specific binding between tryptophan and scFv fragment just as the binding between antigen-antibody. The interaction between Trp and immunoglobulin was a broad-spectrum binding.展开更多
As an intrinsic measure of smoothness, geometric continuity is an important problem in the fields of computer aided geo- metric design. It can afford more degrees of freedom for manipulating the shape of curve. Howeve...As an intrinsic measure of smoothness, geometric continuity is an important problem in the fields of computer aided geo- metric design. It can afford more degrees of freedom for manipulating the shape of curve. However, piecewise polynomial functions of geometrically continuous splines are difficult to be constructed. In this paper, the conversion matrix between geometrically con- tinuous spline basis functions and Bezier representation is analyzed. Based on this, construction of arbitrary degree geometrically continuous spline basis functions can be translated into a solution of linear system of equations. The original construction of geomet- rically continuous spline is simplified.展开更多
Precipitation in super-austenitic stainless steels will significantly affect their corrosion resistance and hot workability.The effects of Cr and Mo on precipitation behaviors were mainly achieved by affecting the dri...Precipitation in super-austenitic stainless steels will significantly affect their corrosion resistance and hot workability.The effects of Cr and Mo on precipitation behaviors were mainly achieved by affecting the driving force for precipitation,especially Mo has a more substantial promotion effect on the formation of theσphase than Cr.In the present study,B addition to the S31254 super-austenitic stainless steels shows an excellent ability to inhibit precipitation.The effect of B on the precipitation behaviors was investigated by microstructure characterization and theoretical calculations.The experimental observation shows that the small addition of B inhibits the formation of theσphase along grain boundaries and changes from continuous to intermittent distribution.Moreover,the inhibitory effect increased obviously with the increase of B content.The influence of B addition was theoretically analyzed from the atomic level,and the calculation results demonstrate that B can inhibit the formation ofσphase precipitates by suppressing Mo migration to grain boundaries.It is found that B and Mo are inclined to segregate atΣ5 andΣ9 grain boundaries,with B showing the most severe grain boundary segregation tendency.While B distribution at the grain boundary before precipitation begins,the segregation of Mo and Cr will be restrained.Additionally,B’s occupation will induce a high potential barrier,making it difficult for Mo to diffuse towards grain boundaries.展开更多
The interactions of 2,2'-bipyridyl with the lanthanide nitrates were studied and complexes of the formula Ln(NO_8)_8(bipy)_8 were isolated from water -ethanol mixed solvent.The complexes were characterized by elem...The interactions of 2,2'-bipyridyl with the lanthanide nitrates were studied and complexes of the formula Ln(NO_8)_8(bipy)_8 were isolated from water -ethanol mixed solvent.The complexes were characterized by elemental analysis, conductivity measurments,IR spectra and DAT-TG analysis.展开更多
Variation of ocean environmental parameters is important to sound ray propagation. This article studies the problem of sound ray propagation in seawater by BELLHOP ray model. The sensitivities of sound ray propagation...Variation of ocean environmental parameters is important to sound ray propagation. This article studies the problem of sound ray propagation in seawater by BELLHOP ray model. The sensitivities of sound ray propagation to the variations of seabed topography and depth of sound source by simulation. The results show that the depth variation of sound source is the main cause for emerging and disappearing of surface sound channel, accumulation area and deep sound channel. The deviation of sound ray propagation is in accordance with seabed topography change.展开更多
As key biomarkers,amyloid-β(Aβ)plaques are frequently used to diagnose Alzheimer’s disease(AD).Although fluorescence imaging has proven to be effective in detecting these plaques,the gold standard probe thioflavin ...As key biomarkers,amyloid-β(Aβ)plaques are frequently used to diagnose Alzheimer’s disease(AD).Although fluorescence imaging has proven to be effective in detecting these plaques,the gold standard probe thioflavin T(ThT),used for Aβaggregates,cannot be applied in vivo owing to its invasive nature.Therefore,the development of novel fluorescent probes capable of identifying Aβplaques in situ is necessary.Based on the ThT structure,twoπ-conjugated heterocyclic D-π-A probes were designed bearing the hydroxytricyanopyrrole acceptor and N,N-dimethylaminophenyl donor.These probes exhibited red to near-infrared fluorescence emission(λ_(max)=732 nm),large Stokes shifts(>100 nm),exceptional signal-to-noise ratio,rapid response(<30 s),and high binding affinity(NT-HTCP=33.32 nmol/L;NF-HTCP=53.35 nmol/L)for Aβaggregates.As the best candidate,NT-HTCP was used for in situ imaging of Aβplaques in AD mouse models.Furthermore,in vivo research demonstrated that NT-HTCP could cross the blood-brain barrier and continue imaging the Aβplaques with a good signal-to-noise ratio.Additionally,the outcomes of the docking computations helped guide the development of the Aβprobes.This study expands the family of N,N-dimethylaminophenyl-based Aβ-sensitive fluorophores,with NTHTCP emerging as a highly promising imaging agent.展开更多
Endocytosis is a fundamental biological process that couples exocytosis to maintain the homeostasis of the plasma membrane and sustained neurotransmission.Super-resolution microscopy enables optical imaging of exocyto...Endocytosis is a fundamental biological process that couples exocytosis to maintain the homeostasis of the plasma membrane and sustained neurotransmission.Super-resolution microscopy enables optical imaging of exocytosis and endocytosis in live cells and makes an essential contribution to understanding molecular mechanisms of endocytosis in neuronal somata and other types of cells.However,visualization of exo-endocytic events at the single vesicular level in a synapse with optical imaging remains a great challenge to reveal mechanisms governing the synaptic exo-endocytotic coupling.In this protocol,we describe the technical details of stimulated emission depletion(STED)imaging of synaptic endocytosis at the single-vesicle level,from sample preparation and microscopy calibration to data acquisition and analysis.展开更多
This paper reports a high-performance H2S gas sensing material that is made of ZnO nanowires(NWs)modified by an optimal amount of ZnS to form nano-hete rojunctions.Compared with the intrinsic ZnONWs,the three differen...This paper reports a high-performance H2S gas sensing material that is made of ZnO nanowires(NWs)modified by an optimal amount of ZnS to form nano-hete rojunctions.Compared with the intrinsic ZnONWs,the three differently modified nano-heterostructure material ZnO-ZnS-x(x=5,10,15)shows significant improvement in sensing performance to H2S at the working temperatures of 100-400℃,especially in the low temperature range(<300℃).The chemiresistive sensor with ZnO-ZnS-10 sensingmaterial exhibits the largest response signal to H2S among all the other ZnO-ZnS-x(x=5,10,15,20)sensors.Its response signal to 5 ppm H2S at 150℃is about 2.7 times to that of the ZnO-NWs sensor.Besides,the ZnO-ZnS-10 sensor also features satisfactory selectivity and repeatability at 150℃.With the technical advantage attributed to the reduction of the redesigned band gap at the interface between ZnO and ZnS,the ZnO-ZnS hete ro structure sensor rather than the traditional ZnO-NWs sensor can be used for high-sensitivity application at low working temperature.展开更多
Lateral transportation of soil heavy metals in rainfall events could significantly increase the scope of pollution. Therefore, it is necessary to develop a model with high accuracy to simulate the migration quantity o...Lateral transportation of soil heavy metals in rainfall events could significantly increase the scope of pollution. Therefore, it is necessary to develop a model with high accuracy to simulate the migration quantity of heavy metals. A model for heavy metal migration simulation was developed based on the SWAT(Soil and Water Assessment Tool) model. This model took into consideration the influence of soil p H value, soil particle size, runoff volume, sediment amount,concentration of water-soluble heavy metals dissolved in runoff and insoluble absorbed to the soil particles. This model was reasonable in Huanjiang watershed, Guangxi Zhuang Autonomous Region, south China, covering an area of 273 km^2. The optimal drainage area threshold was determined by analyzing the effects of watershed subdivision on the simulation results to ensure the simulation accuracy. The main conclusions of this paper were:(1) watershed subdivision could affect simulation migration quantity of heavy metals;(2) the quantity of heavy metals transported by sediment accounted for 97%–99% of the total migration quantity in the study watershed. Therefore, sediment played the most important role in heavy metal migration;(3) the optimal drainage area threshold percentage to ensure high simulation accuracy was determined to be 2.01% of the total watershed;(4) with the optimal threshold percentage, this model could simulate the migration quantity of As, Pb and Cd accurately at the total watershed and subwatershed level. The results of this paper were useful for identifying the key regions with heavy metal migration.展开更多
An index system for evaluation of technologies for urban river rehabilitation was proposed and discussed.The index system includes indicators of cost,resources,environmental improvement,and social effects.The calculat...An index system for evaluation of technologies for urban river rehabilitation was proposed and discussed.The index system includes indicators of cost,resources,environmental improvement,and social effects.The calculation method for an objective value of each index based on its attributes and weights was presented.The Foshan Channel,which is a seriously polluted,black and malodorous urban river in Foshan City,China,was selected as a case study.The values of the attributes and the weights of the indices for the Foshan Channel were determined.The technologies for the rehabilitation of the Foshan Channel were evaluated based on this index system.Finally,a rehabilitation scheme for the Foshan Channel was proposed.展开更多
Effects of compression deformation on the sigma-phase precipitation behavior of B-containing S31254 stainless steel after solution treatment were studied using the Gleeble compression test. The cold and hot processing...Effects of compression deformation on the sigma-phase precipitation behavior of B-containing S31254 stainless steel after solution treatment were studied using the Gleeble compression test. The cold and hot processing characteristics of B-containing S31254 stainless steel were evaluated, and the results show that the speed of compression deformation increased the precipitation rate of the sigma phase, and the location of precipitation extended from the austenite grain boundary to the original hot rolling deformation area. During cold deformation at room temperature, the precipitation rate increased when the deformation reached at 40%. Deformation at 950℃ affected precipitation more obviously. At 1074 ℃, when the deformation reached 20%, the precipitated phases started increasing, and above this deformation range, precipitation began decreasing. Also, at 1074℃ the deformation accelerated the precipitation of sigma phase;but with deformation, there was a change in critical temperature for the sigma-phase excursion. The precipitation position of the sigma phase is strongly related to the area of the original hot rolling deformation. With an increase in the deformation amount, precipitates in this region appeared as coarse-grained, skeletal, and network-like features.展开更多
The adsorption and diffusion of N on γ-Fe-Al (111) surface have been investigated using the first principle calculations combined with density functional theory to explore the formation mechanism of AlN in the oxidat...The adsorption and diffusion of N on γ-Fe-Al (111) surface have been investigated using the first principle calculations combined with density functional theory to explore the formation mechanism of AlN in the oxidation process of austenitic stainless steel. The results indicate that the most preferential adsorption site of N on the surface of γ-Fe (111) is fcc-hollow site. In addition, the stable positions are located at fcc adsorption site on clean and Al-doped γ-Fe (111) surface adsorbed 4.76 at.% N. Compared with the pure Fe system,γ-Fe-Al (111) system reduces the energy difference of N from the surface to the bulk. The system is most stable for 9.09 at.% N adsorbed on the octahedral interstice of the 2nd and 3rd atom interlamination of γ-Fe-Al (111) surface. Thus, the doping of Al makes it easier to spread N on the surface of γ-Fe (111). The increase in N in the atmosphere also accelerates the diffusion. Moreover, according to the density of states analysis, the interaction between Al and N was enhanced when 9.09 at.% N was adsorbed on the surface of γ-Fe-Al (111).展开更多
基金supported by the Shenyang City-School Joint Funding Project (No.2400022093).
文摘Background:Hepatocellular carcinoma(HCC)appears to be strongly associated with immune-related genes.However,immune-related genes are not well understood as a prognostic marker in HCC caused by the hepatitis B virus(HBV).The purpose of this study was to investigate the prognostic significance of immune-related genes in HBV-infected HCC.Methods:Gene expression data from 114 HBV-infected HCC and 50 normal tissues were integrated into The Cancer Genome Atlas.Differentially expressed immune-associated genes were analyzed to identify immune-associated differential genes associated with overall survival.Least Absolute Shrinkage and Selection Operator and multivariate Cox regressions were used to constructing immunoprognostic models.An independent prognostic factor analysis using multiple Cox regressions was also performed for HBV-infected HCCs.Immunocorrelation analysis markers and immune cell infiltration were also investigated.Results:We found 113 differentially expressed immune-associated genes.Immune-related differential genes were significantly correlated with the overall survival of HCC patients.We constructed an immune-based prognostic model using multivariate Cox regression analysis including seven immune-related genes.According to further analysis,immune-related prognostic factors may serve as independent prognostic indicators in the clinical setting.There is also evidence that the 7-gene prognostic model reflects the tumor immune microenvironment as a result of the risk score model and immune cell infiltration.Conclusions:As a result of our study,we screened immune-related genes for prognosis in HBV-infected HCC and developed a novel immune-based prognostic model.The research not only provides new prognostic biomarkers but also offers insight into the tumor immune microenvironment and lays the theoretical groundwork for immunotherapy.
文摘目的利用高分辨磁共振成像(high-resolution magnetic resonance imaging,HR-MRI)探究短暂性脑缺血发作(transient ischemic attack,TIA)频发组与非频发组间基底动脉管壁差异。材料与方法将经过头部三维时间飞跃法磁共振血管造影(three-dimension time of flight magnetic resonance angiography,3D-TOF-MRA)和基底动脉HR-MRI扫描后发现斑块的患者纳入研究。根据24 h内TIA频次分为频发组(≥2次)和非频发组(<2次)。对两组斑块形态学指标、狭窄程度、血管重构、斑块分布及临床特点进行分析。结果68例TIA患者,共184个斑块(频发组:38例、108个,非频发组:30例、76个)。最狭窄层面的斑块形态学指标组间差异均有统计学意义(P均<0.05)。频发组狭窄程度、重构指数较非频发组高,差异均有统计学意义(P均<0.05)。频发组腹侧斑块占比较大(38.0%vs 22.4%),背侧斑块占比较小(17.6%vs 35.5%),差异均有统计学意义(P=0.025、0.006);两组侧壁斑块比例(44.4%vs 42.1%)相似,差异无统计学意义(P=0.753)。两组临床因素差异均无统计学意义(P均>0.05)。结论频发组斑块多分布于腹侧,非频发组多分布于背侧,两组侧壁斑块比例相似。频发组斑块负荷、狭窄程度、重构指数更高,非频发组斑块更稳定。
基金supported by the Science&Technology Development Fund of Tianjin Education Commission for Higher Education,Tianjin,China(Grant No.2017KJ200)。
文摘Objective:Patients with cancer pain are highly dependent on morphine analgesia,but studies have shown a negative correlation between morphine demand and patient outcomes.The long-term use of morphine may result in abnormally elevated serum morphine-3-glucuronide(M3G)levels.Hence,the effects of M3G on tumor progression are worth studying.Methods:The effects of M3G on PD-L1 expressions in human non-small cell lung cancer(NSCLC)cell lines were first evaluated.Activation of TLR4 downstream pathways after M3G treatment was then determined by Western blot.The effects of M3G on human cytotoxic T lymphocytes(CTL)cytotoxicity and INF-γrelease was also detected.Finally,the LLC murine lung adenocarcinoma cell line were used to establish a murine lung cancer model,and the effects of M3G on tumor growth and metastasis were determined.Results:M3G promoted the expressions of PD-L1 in the A549 and H1299 cell lines in a TLR4-dependent manner(P<0.05).M3G activated the PI3 K and the NFκB signaling pathways,and this effect was antagonized by a TLR4 pathway inhibitor.A PI3 K pathway inhibitor reversed the M3G-mediated PD-L1 upregulation.M3G inhibited the cytotoxicity of CTL on A549 cells and decreased the level of INF-γ.Repeated M3G intraperitoneal injections promoted LLC tumor growth and lung metastasis through the upregulation of tumor expressed PD-L1 and the reduction of CTL in the tumor microenvironment.Conclusions:M3G specifically activated TLR4 in NSCLC cells and upregulated PD-L1 expression through the PI3 K signaling pathway,thereby inhibiting CTL cytotoxicity and finally promoting tumor immune escape.
基金This research work was supported by The National Key Project of Fundamental Research and Advances(G1999064707).
文摘Myasthenia Gravis (MG) is an organ specific autoimmune disease mediated by autoantibodies (AChR Ab) against the acetylcholine receptor (AChR). Literature reported that the AChR Ab can be removed by absorbent linked with tryptophan. It was studied in detail in our lab. With the aid of computer, we docked some ligands into AChR Ab, and the results from scores of docking under different generations showed that there was no specific binding between tryptophan and scFv fragment just as the binding between antigen-antibody. The interaction between Trp and immunoglobulin was a broad-spectrum binding.
基金Supported by NSFC (No.61100129)Long-span Building Construction Research Project (No.40006014201101)
文摘As an intrinsic measure of smoothness, geometric continuity is an important problem in the fields of computer aided geo- metric design. It can afford more degrees of freedom for manipulating the shape of curve. However, piecewise polynomial functions of geometrically continuous splines are difficult to be constructed. In this paper, the conversion matrix between geometrically con- tinuous spline basis functions and Bezier representation is analyzed. Based on this, construction of arbitrary degree geometrically continuous spline basis functions can be translated into a solution of linear system of equations. The original construction of geomet- rically continuous spline is simplified.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.U1860204 and 51871159)。
文摘Precipitation in super-austenitic stainless steels will significantly affect their corrosion resistance and hot workability.The effects of Cr and Mo on precipitation behaviors were mainly achieved by affecting the driving force for precipitation,especially Mo has a more substantial promotion effect on the formation of theσphase than Cr.In the present study,B addition to the S31254 super-austenitic stainless steels shows an excellent ability to inhibit precipitation.The effect of B on the precipitation behaviors was investigated by microstructure characterization and theoretical calculations.The experimental observation shows that the small addition of B inhibits the formation of theσphase along grain boundaries and changes from continuous to intermittent distribution.Moreover,the inhibitory effect increased obviously with the increase of B content.The influence of B addition was theoretically analyzed from the atomic level,and the calculation results demonstrate that B can inhibit the formation ofσphase precipitates by suppressing Mo migration to grain boundaries.It is found that B and Mo are inclined to segregate atΣ5 andΣ9 grain boundaries,with B showing the most severe grain boundary segregation tendency.While B distribution at the grain boundary before precipitation begins,the segregation of Mo and Cr will be restrained.Additionally,B’s occupation will induce a high potential barrier,making it difficult for Mo to diffuse towards grain boundaries.
文摘The interactions of 2,2'-bipyridyl with the lanthanide nitrates were studied and complexes of the formula Ln(NO_8)_8(bipy)_8 were isolated from water -ethanol mixed solvent.The complexes were characterized by elemental analysis, conductivity measurments,IR spectra and DAT-TG analysis.
文摘Variation of ocean environmental parameters is important to sound ray propagation. This article studies the problem of sound ray propagation in seawater by BELLHOP ray model. The sensitivities of sound ray propagation to the variations of seabed topography and depth of sound source by simulation. The results show that the depth variation of sound source is the main cause for emerging and disappearing of surface sound channel, accumulation area and deep sound channel. The deviation of sound ray propagation is in accordance with seabed topography change.
基金supported by the National Natural Science Foundation of China(Nos.22164006,82060626,and 81360471).
文摘As key biomarkers,amyloid-β(Aβ)plaques are frequently used to diagnose Alzheimer’s disease(AD).Although fluorescence imaging has proven to be effective in detecting these plaques,the gold standard probe thioflavin T(ThT),used for Aβaggregates,cannot be applied in vivo owing to its invasive nature.Therefore,the development of novel fluorescent probes capable of identifying Aβplaques in situ is necessary.Based on the ThT structure,twoπ-conjugated heterocyclic D-π-A probes were designed bearing the hydroxytricyanopyrrole acceptor and N,N-dimethylaminophenyl donor.These probes exhibited red to near-infrared fluorescence emission(λ_(max)=732 nm),large Stokes shifts(>100 nm),exceptional signal-to-noise ratio,rapid response(<30 s),and high binding affinity(NT-HTCP=33.32 nmol/L;NF-HTCP=53.35 nmol/L)for Aβaggregates.As the best candidate,NT-HTCP was used for in situ imaging of Aβplaques in AD mouse models.Furthermore,in vivo research demonstrated that NT-HTCP could cross the blood-brain barrier and continue imaging the Aβplaques with a good signal-to-noise ratio.Additionally,the outcomes of the docking computations helped guide the development of the Aβprobes.This study expands the family of N,N-dimethylaminophenyl-based Aβ-sensitive fluorophores,with NTHTCP emerging as a highly promising imaging agent.
基金National Natural Science Foundation of China(32171233,81901308,81974203,32300819,31670843,32000704,21790390,and 21790394)Key Research and Development Program of Shaanxi Province of China(2023-ZDLSF-23)+5 种基金Natural Science Foundation of Shaanxi Province of China(2019JC-07,2020JQ-029,and 2023-JC-QN-0236)Natural Science Foundation of Sichuan Province of China(2020YJ0337 and 2020YJ0378)Sichuan Science and Technology Program(2022YFS0615)China Postdoctoral Science Foundation(2018M640972)Innovation Capability Support Program of Shaanxi Province,China(2021TD-37)The Shaanxi Postdoc Funding(2023BSHTBZZ15,2023BSHYDZZ39 and 2023BSHEDZZ67).
文摘Endocytosis is a fundamental biological process that couples exocytosis to maintain the homeostasis of the plasma membrane and sustained neurotransmission.Super-resolution microscopy enables optical imaging of exocytosis and endocytosis in live cells and makes an essential contribution to understanding molecular mechanisms of endocytosis in neuronal somata and other types of cells.However,visualization of exo-endocytic events at the single vesicular level in a synapse with optical imaging remains a great challenge to reveal mechanisms governing the synaptic exo-endocytotic coupling.In this protocol,we describe the technical details of stimulated emission depletion(STED)imaging of synaptic endocytosis at the single-vesicle level,from sample preparation and microscopy calibration to data acquisition and analysis.
基金the support from National Key R&D Program of China(No.2016YFA0200800)the National Natural Science Foundation of China(Nos.61527818,61834007,61604165,61571430,61874130,61674160)Science and Technology Development Fund of Shanghai Institute of Technology。
文摘This paper reports a high-performance H2S gas sensing material that is made of ZnO nanowires(NWs)modified by an optimal amount of ZnS to form nano-hete rojunctions.Compared with the intrinsic ZnONWs,the three differently modified nano-heterostructure material ZnO-ZnS-x(x=5,10,15)shows significant improvement in sensing performance to H2S at the working temperatures of 100-400℃,especially in the low temperature range(<300℃).The chemiresistive sensor with ZnO-ZnS-10 sensingmaterial exhibits the largest response signal to H2S among all the other ZnO-ZnS-x(x=5,10,15,20)sensors.Its response signal to 5 ppm H2S at 150℃is about 2.7 times to that of the ZnO-NWs sensor.Besides,the ZnO-ZnS-10 sensor also features satisfactory selectivity and repeatability at 150℃.With the technical advantage attributed to the reduction of the redesigned band gap at the interface between ZnO and ZnS,the ZnO-ZnS hete ro structure sensor rather than the traditional ZnO-NWs sensor can be used for high-sensitivity application at low working temperature.
基金supported by the Hi-Tech Research and Development Program(863)of China(No.2014AA06A513)the Beijing Postdoctoral Research Foundation+2 种基金the Project of Heavy Metal Risk Warning and Phytoremediation in Mining Concentrated Area(No.GJHZ201308)the Special Fund for Environment Protection Research in the Public Interest(No.201409044)the Study on Heavy Metal Accumulation Risk and Early Warning in Typical Ore Concentration Area(No.201111020-4)
文摘Lateral transportation of soil heavy metals in rainfall events could significantly increase the scope of pollution. Therefore, it is necessary to develop a model with high accuracy to simulate the migration quantity of heavy metals. A model for heavy metal migration simulation was developed based on the SWAT(Soil and Water Assessment Tool) model. This model took into consideration the influence of soil p H value, soil particle size, runoff volume, sediment amount,concentration of water-soluble heavy metals dissolved in runoff and insoluble absorbed to the soil particles. This model was reasonable in Huanjiang watershed, Guangxi Zhuang Autonomous Region, south China, covering an area of 273 km^2. The optimal drainage area threshold was determined by analyzing the effects of watershed subdivision on the simulation results to ensure the simulation accuracy. The main conclusions of this paper were:(1) watershed subdivision could affect simulation migration quantity of heavy metals;(2) the quantity of heavy metals transported by sediment accounted for 97%–99% of the total migration quantity in the study watershed. Therefore, sediment played the most important role in heavy metal migration;(3) the optimal drainage area threshold percentage to ensure high simulation accuracy was determined to be 2.01% of the total watershed;(4) with the optimal threshold percentage, this model could simulate the migration quantity of As, Pb and Cd accurately at the total watershed and subwatershed level. The results of this paper were useful for identifying the key regions with heavy metal migration.
基金the Programme of Introducing Talents of Discipline to Universities(No.B07002)the National Water Pollution Control Special Project(No.2008ZX07313-006).
文摘An index system for evaluation of technologies for urban river rehabilitation was proposed and discussed.The index system includes indicators of cost,resources,environmental improvement,and social effects.The calculation method for an objective value of each index based on its attributes and weights was presented.The Foshan Channel,which is a seriously polluted,black and malodorous urban river in Foshan City,China,was selected as a case study.The values of the attributes and the weights of the indices for the Foshan Channel were determined.The technologies for the rehabilitation of the Foshan Channel were evaluated based on this index system.Finally,a rehabilitation scheme for the Foshan Channel was proposed.
基金The present work was financially supported by National Natural Science Foundation of China (Grant No. 51371123)the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 2013140211003)+1 种基金Shanxi Natural Science Foundation Project (Grant Nos. 2014011002-1, 201601D202033, 201601D202034)Innovation Project for Graduate Education of Shanxi province (Grant No. 2016JD20).
文摘Effects of compression deformation on the sigma-phase precipitation behavior of B-containing S31254 stainless steel after solution treatment were studied using the Gleeble compression test. The cold and hot processing characteristics of B-containing S31254 stainless steel were evaluated, and the results show that the speed of compression deformation increased the precipitation rate of the sigma phase, and the location of precipitation extended from the austenite grain boundary to the original hot rolling deformation area. During cold deformation at room temperature, the precipitation rate increased when the deformation reached at 40%. Deformation at 950℃ affected precipitation more obviously. At 1074 ℃, when the deformation reached 20%, the precipitated phases started increasing, and above this deformation range, precipitation began decreasing. Also, at 1074℃ the deformation accelerated the precipitation of sigma phase;but with deformation, there was a change in critical temperature for the sigma-phase excursion. The precipitation position of the sigma phase is strongly related to the area of the original hot rolling deformation. With an increase in the deformation amount, precipitates in this region appeared as coarse-grained, skeletal, and network-like features.
基金The authors would like to acknowledge the support of National Natural Science Foundation of China (Nos. 51371123 and 21576178)Natural Science Foundation of Shanxi Province (Nos. 201601D202034 and 2015011034)Key Laboratory of Magnetic Molecules & Magnetic Information Materials Ministry of Education, Shanxi Normal University, the China Scholarship Council (CSC).
文摘The adsorption and diffusion of N on γ-Fe-Al (111) surface have been investigated using the first principle calculations combined with density functional theory to explore the formation mechanism of AlN in the oxidation process of austenitic stainless steel. The results indicate that the most preferential adsorption site of N on the surface of γ-Fe (111) is fcc-hollow site. In addition, the stable positions are located at fcc adsorption site on clean and Al-doped γ-Fe (111) surface adsorbed 4.76 at.% N. Compared with the pure Fe system,γ-Fe-Al (111) system reduces the energy difference of N from the surface to the bulk. The system is most stable for 9.09 at.% N adsorbed on the octahedral interstice of the 2nd and 3rd atom interlamination of γ-Fe-Al (111) surface. Thus, the doping of Al makes it easier to spread N on the surface of γ-Fe (111). The increase in N in the atmosphere also accelerates the diffusion. Moreover, according to the density of states analysis, the interaction between Al and N was enhanced when 9.09 at.% N was adsorbed on the surface of γ-Fe-Al (111).
