The plant cell wall is an extremely complicated natural nanoscale structure composed of cellulose microfibrils embedded in a matrix of noncellulosic polysaccharides,further reinforced by the phenolic compound lignins ...The plant cell wall is an extremely complicated natural nanoscale structure composed of cellulose microfibrils embedded in a matrix of noncellulosic polysaccharides,further reinforced by the phenolic compound lignins in some cell types.Such a network formed by the interactions of multiscale polymers actually reflects functional form of the cell wall to meet the requirements of plant cell functionalization.Therefore,how plants assemble cell wall functional structure is fundamental in plant biology and critical for crop trait formation and domestication as well.Due to the lack of effective analytical techniques to characterize this fundamental but complex network,it remains difficult to establish direct links between cell-wall genes and phenotypes.The roles of plant cell walls are often underestimated as indirect.Over the past decades,many genes involved in cell wall biosynthesis,modification,and remodeling have been identified.The application of a variety of state-of-the-art techniques has made it possible to reveal the fine cell wall networks and polymer interactions.Hence,many exciting advances in cell wall biology have been achieved in recent years.This review provides an updated overview of the mechanistic and conceptual insights in cell wall functionality,and prospects the opportunities and challenges in this field.展开更多
In neurosurgery procedures,cerebrospinal fluid leakage is a commonly encountered complication.Re-constructing skull base defects with patch materials can reduce the risk of cerebrospinal fluid leakage which can lead t...In neurosurgery procedures,cerebrospinal fluid leakage is a commonly encountered complication.Re-constructing skull base defects with patch materials can reduce the risk of cerebrospinal fluid leakage which can lead to serious issues such as infection,meningitis,arachnoiditis,and delayed wound healing.An ideal skull base reconstruction material should not only serve as a leak-proof barrier but also pro-mote skull base bone regeneration.To fulfill this challenge,this research designed and fabricated a Janus orthogonal bilayer nanofiber membrane(OPCL/PG-PCPP).The aligned PCL(APCL)nanofibers were con-stituted as the top layer to resist cerebrospinal fluid leakage,while the perpendicular PCL/gelatin(APG)fibers with calcium polyphosphate encapsulated polydopamine nanoparticles(CPP@PDA,labeled as PCPP)were designed as the bottom layer(APG-PCPP)to facilitate osteoblast migration and osteogenic differen-tiation.Among these,APG-1%PCPP nanofibers demonstrated the most effective induction of osteogenic differentiation in bone marrow mesenchymal stem cells(rBMSCs).Subsequent in vivo animal experi-ments revealed that the bone surface area(BS),bone volume fraction(BV/TV),and number of trabec-ulae(Tb.N)in the APG-1%PCPP group were twice as high as those in the control group,which confirmed the good osteogenic potentials.Therefore,due to its unique leak-proof and osteoinductive properties,the OPCL/PG-PCPP membrane holds promise as an applicable skull base reconstruction material in the field of neurosurgery.展开更多
Structured design helps to play out the coordination advantage and optimize the performance of electro-chemical reactions.In this work,hierarchical hollow microspheres(Co_(3)S_(4)@NiCo_(2)S_(4)) with unique core-shell...Structured design helps to play out the coordination advantage and optimize the performance of electro-chemical reactions.In this work,hierarchical hollow microspheres(Co_(3)S_(4)@NiCo_(2)S_(4)) with unique core-shell heterostructure were successfully prepared through simple template and solvothermal methods.Thanks to the hollow structure,cross-linked nanowire arrays,and in-situ coating of zeolite imidazole framework(ZIF),Co_(3)S_(4)@NiCo_(2)S_(4) demonstrated excellent electrochemical performance with a specific ca-pacitance of up to 2697.7 F g^(-1)at 1 A g^(-1) and cycling stability of 80.5% after 5000 cycles.The covalent organic framework(COF)derived nano carbon,which had undergone secondary calcination and ZnCl_(2) activation,also exhibited excellent double-layer energy storage performance.Compared to a single calci-nation,the incredible increase in capacitance was up to 208.5 times greater,reaching 291.9 F g^(-1)at 1 A g^(-1)while maintaining ultra-high rate performance(81.0%at 20 A g^(-1)).The hybrid supercapacitor,assem-bled with Co_(3)S_(4)@NiCo_(2)S_(4)as the cathode and COF-derived carbon as the anode,exhibited an extremely high energy density(79.7 Wh kg^(-1)at 693.5 W kg^(-1))and excellent cyclic stability(maintained 79.3%after 10,000 cycles of 20 A g^(-1)),further explaining the reliable and practical characteristics.This work provided reference for the structural optimization of transition metal sulfides and the high-temperature activation of COF-derived carbon.展开更多
Unmanned Aerial Vehicle(UAV)swarms have been foreseen to play an important role in military applications in the future,wherein they will be frequently subjected to different disturbances and destructions such as attac...Unmanned Aerial Vehicle(UAV)swarms have been foreseen to play an important role in military applications in the future,wherein they will be frequently subjected to different disturbances and destructions such as attacks and equipment faults.Therefore,a sophisticated robustness evaluation mechanism is of considerable importance for the reliable functioning of the UAV swarms.However,their complex characteristics and irregular dynamic evolution make them extremely challenging and uncertain to evaluate the robustness of such a system.In this paper,a complex network theory-based robustness evaluation method for a UAV swarming system is proposed.This method takes into account the dynamic evolution of UAV swarms,including dynamic reconfiguration and information correlation.The paper analyzes and models the aforementioned dynamic evolution and establishes a comprehensive robustness metric and two evaluation strategies.The robustness evaluation method and algorithms considering dynamic reconfiguration and information correlation are developed.Finally,the validity of the proposed method is verified by conducting a case study analysis.The results can further provide some guidance and reference for the robust design,mission planning and decision-making of UAV swarms.展开更多
Objective：The programmed cell death-1 receptor/programmed cell death-1 ligand （PD-1/PD-L1） pathway plays a crucial role in tumor evasion from host immunity.This study was designed to evaluate the association betwee...Objective：The programmed cell death-1 receptor/programmed cell death-1 ligand （PD-1/PD-L1） pathway plays a crucial role in tumor evasion from host immunity.This study was designed to evaluate the association between circulating PD-L1 expression and prognosis in patients with advanced gastric cancer.Methods：Totally 80 advanced gastric cancer patients and 40 health controls from Beijing Cancer Hospital were enrolled in the present study.Circulating PD-L1 expression was tested by enzymelinked immunosorbent assay （ELISA）.The associations between the expression level of PD-L1 and clinicopathological features and prognosis were analyzed statistically.Results：Expression of PD-L1 in advanced gastric cancer patients was significandy up-regulated compared with health people （P=0.006）.The expression of PD-L1 was significantly correlated with differentiation and lymph node metastasis （P=0.026 and P=0.041,respectively）.Although we didn＇t find significant difference in all advanced gastric cancer patients with different PD-L1 expression,the adenocarcinoma patients with higher up-regulated PD-L1 expression had much better prognosis than low expression patients （65.6％ vs.44.7％,P=0.028）.Conclusions：PD-L1 was elevated in advance gastric cancer patients and may play an important role in tumor immune evasion and patients prognosis.展开更多
Reliable and accurate pre-implantation genetic diagnosis （PGD） of patient＇s embryos by next-generation sequencing （NGS） is dependent on efficient whole genome amplification （WGA） of a representative biopsy samp...Reliable and accurate pre-implantation genetic diagnosis （PGD） of patient＇s embryos by next-generation sequencing （NGS） is dependent on efficient whole genome amplification （WGA） of a representative biopsy sample. However, the performance of the current state of the art WGA methods has not been evaluated for sequencing. Using low template DNA （15 pg） and single cells, we showed that the two PCR-based WGA systems SurePlex and MALBAC are superior to the REPLI-g WGA multiple displacement amplification （MDA） system in terms of consistent and reproducible genome coverage and sequence bias across the 24 chromosomes, allowing better normalization of test to reference sequencing data. When copy number variation sequencing （CNV-Seq） was applied to single cell WGA products derived by either SurePlex or MALBAC amplification, we showed that known disease CNVs in the range of 3-15 Mb could be reliably and accurately detected at the correct genomic positions. These findings indicate that our CNV-Seq pipeline incorporating either SurePlex or MALBAC as the key initial WGA step is a powerful methodology for clinical PGD to identify euploid embryos in a patient＇s cohort for uterine transplantation,展开更多
Objective： To investigate Leucine-rich repeat-containing G protein-coupled receptor 5 （LGR5） expressions in gastric cancer and to evaluate its clinical significance. Methods： LGR5 expression was assessed by immuno...Objective： To investigate Leucine-rich repeat-containing G protein-coupled receptor 5 （LGR5） expressions in gastric cancer and to evaluate its clinical significance. Methods： LGR5 expression was assessed by immunohistochemistry in 257 gastric cancer patients after surgery. The relationships between LGR5 expression and clinicopathological features and patients prognosis were statistically analyzed. Results： The expression of LGR5 was significantly higher in gastric cancers as a cancer stem cell marker than in adjacent normal tissues （P〈0.001）, and more frequently in patients with intestinal type, well-moderate differentiation and stage I and II （P〈0.05）. Although we found gastric cancer patients with LGR5 positive expression had a poorer prognosis, it didn＇t meet statistical significance （P〉0.05）. LGR5 negative expression was significantly related to the favorable overall survival in stage I and II gastric cancer patients （P〈0.05）. Furthermore, patients with high LGR5 expression tended to be more likely to get progression and have poorer progress-free survival （P〈0.05）. Multivariate Cox regression analysis revealed that LGR5 expression was an independent factor of overall survival for the patients with stage I and II gastric cancer （P〈0.05）. Conclusions： Our results show that LGR5 may play an important role in tumorigenesis and progression and would be a powerful marker to predict the prognosis of patients with stage I and II gastric cancer.展开更多
With the development of Unmanned Aerial Vehicle(UAV) system autonomy, network communication technology and group intelligence theory, mission execution in the form of a UAV swarm will be an important realization of fu...With the development of Unmanned Aerial Vehicle(UAV) system autonomy, network communication technology and group intelligence theory, mission execution in the form of a UAV swarm will be an important realization of future applications. Traditional single-UAV mission reliability modeling methods have been unable to meet the requirements of UAV swarm mission reliability modeling. Therefore, the UAV swarm mission reliability modeling and evaluation method is proposed. First, aimed at the interdependence among the multiple layers, a multi-layer network model of a UAV swarm is established. At the same time, based on the system having the following characteristics—using a mission chain to complete the mission and applying the connectivity of the mission network—the mission network model of a UAV swarm is established. Second, vulnerability and connectivity are selected as two indicators to reflect the reliability of the mission, and aimed at random attack and deliberate attack, vulnerability and connectivity evaluation methods are proposed. Finally, the validity and accuracy of the constructed model are verified through simulations,and the model and selected indicators can meet the reliability requirements of the UAV swarm mission. In this way, this study provides quantitative reference for UAV-swarm-related decisionmaking work and supports the development of UAV-swarm-related work.展开更多
The Cu/CeO_(2)nanoporous composite material was prepared via a one-step and energy-saving method of solution combustion synthesis(SCS).The phase composition,surface morphology and optical characteristics of Cu/CeO_(2)...The Cu/CeO_(2)nanoporous composite material was prepared via a one-step and energy-saving method of solution combustion synthesis(SCS).The phase composition,surface morphology and optical characteristics of Cu/CeO_(2)were studied.The results show that the SCS products are composed of cubic fluorite CeO_(2)and Cu.Due to the generation and escape of gas during the synthetic reaction,the SCS CeO_(2)shows porous structure,in which the mesopores(diameter 10-17 nm)nest in the wall of large pores(diameter80-300 nm).X-ray photoelectron spectroscopy(XPS)outcomes indicate that the oxygen vacancy concentration of CeO_(2)increases(18.97%-30.93%)with the increase of Cu concentration.The decoration of Cu greatly enhances the catalytic activity of CeO_(2)nanomaterials.30 wt%Cu/CeO_(2)composite material shows the best photocatalytic activities for the degradation of methyl orange(MO)(95.99%),which is about 4.3times that of CeO_(2)at the same time(120 min).UV-vis diffuse reflectance spectroscopy(DRS)results show that the semiconductor band gap is reduced with the addition of metallic Cu,which leads to the enhancement of photocatalytic activity.The free radical trapping experiments demonstrate that·O_(2)-and h+are the main active species in the photocatalytic degradation of MO.Based on the above results,a hypothesized mechanism for enhanced photocatalysis of Cu/CeO_(2)nanomaterials was proposed:the porous structure provides more reactive sites and channels for mass transfer,and the presence of metallic Cu improves the oxygen vacancy concentration of CeO_(2)and then promotes charge-carrier separation,which helps enhance the photocatalytic performance of Cu/CeO_(2).展开更多
This paper gives the truncated version of the Minpert method:the incomplete minimum perturbation algorithm(IMinpert).It is based on an incomplete orthogonal-ization of the Krylov vectors in question,and gives a quasi-...This paper gives the truncated version of the Minpert method:the incomplete minimum perturbation algorithm(IMinpert).It is based on an incomplete orthogonal-ization of the Krylov vectors in question,and gives a quasi-minimum backward error solution over the Krylov subspace.In order to make the practical implementation of IMinpert easy and convenient,we give another approximate version of the IMinpert method:A-IMinpert.Theoretical properties of the latter algorithm are discussed.Nu-merical experiments are reported to show the proposed method is effective in practice and is competitive with the Minpert algorithm.展开更多
Here,we report a series of Bi^(3+)-doped Ba_(2)Y_(1-x)Sc_(x)NbO_(6)(0≤x≤1.0 mol)phosphors by using the traditional high temperature solid-state reaction.To achieve the structural and photoluminescent(PL)information,...Here,we report a series of Bi^(3+)-doped Ba_(2)Y_(1-x)Sc_(x)NbO_(6)(0≤x≤1.0 mol)phosphors by using the traditional high temperature solid-state reaction.To achieve the structural and photoluminescent(PL)information,several experimental characterizations and theoretical calculations were carried out,including X-ray diffraction(XRD),Rietveld refinement,UV-visible diffuse reflectance and PL spectra,temperature dependent PL spectra,and density functional theo retical(DFT)calculations.The XRD results show that the Bi^(3+)-doped Ba_(2)Y_(1-x)Sc_(x)NbO_(6)samples belong to the double-perovskite phase with a cubic space group of Fm3 m,and the diffraction positions shift toward high diffraction angle when the larger Y^(3+)ions are gradually replaced by the smaller Sc^(3+)ions.In addition,the refined XRD findings show that the Bi^(3+)ions tend to substitute the Y^(3+)and Sc^(3+)sites in the Bi^(3+)-doped Ba_(2)Y_(1-x)Sc_(x)NbO_(6)0<x<1.0 mol)solid solutions.The PL spectra show that the emission positions of the solid solution samples tune from446 to 497 nm with the increase of Sc^(3+) content,which can be attributed to the modification of crystal field strength around Bi^(3+)ions.Moreover,there is energy transfer from the Ba_(2)YNbO_(6)host to Bi^(3+)ions,which is dominated by a resonant type via a dipole-quadrupole(d-q)interaction.The Ba_(2)Y_(0.6)Sc_(0.4)NbO_(6):0.02 molBi^(3+)shows the strongest PL intensity under 365 nm excitation,with the best quantum efficiency(QE)of 68%,and it keeps 60%of the room temperature emission intensity when the temperature increases to 150℃,meaning that the Ba_(2)Y_(0.6)Sc_(0.4)NbO_(6):Bi^(3+)features excellent thermal quenching of luminescence.By combining this optimal sample with a commercial red-emitting Sr_(2)Si_(5)N_(8):Eu^(2+)phosphor,and a commercial 365 nm UV LED chip,a white LED device,with the color temperature(CT)of 3678 K,color rendering index(CRI)of 67.9,and CIE coordinates at(0.371,0.376),is achieved.展开更多
The N-doped bismuth tungstate （BizWOt） photocatalysts with high visible light activity were prepared by the hydrothermal method using urea as a nitrogen source. The as-prepared N-doped Bi2WO6 samoles were characteri...The N-doped bismuth tungstate （BizWOt） photocatalysts with high visible light activity were prepared by the hydrothermal method using urea as a nitrogen source. The as-prepared N-doped Bi2WO6 samoles were characterized by X-ray diffraction, scanning electron microscopy, specific surface area, photocurrent analysis, and UV-Vis diffuse re- flectrance spectroscopy. The photocatalytic activity was evaluated by photocatalytic degradation of rhodamine B （RhB） solution under visible light irradiation. The photocatalytic mechanisms were analyzed by active species trapping experi- ments which revealed that the holes were the main active species of N-doped BizWO6 products in aqueous solution under visible light irradiation, rather than .OH and O-. With the assistance of H202, the photocatalytic activity for degradation of RhB could be further improved because H202 reacted with conduction band electrons to generate more hydroxyl radicals. KEY WORDS：展开更多
Porous TiAl3 intermetallics were fabricated through vacuum reactive sintering from Ti-75A1 at.% elemental powder mixture.The phase compositions,expansion behaviors,pore characteristics and microstructure evolution of ...Porous TiAl3 intermetallics were fabricated through vacuum reactive sintering from Ti-75A1 at.% elemental powder mixture.The phase compositions,expansion behaviors,pore characteristics and microstructure evolution of TiAl3 intermetallics were investigated,and the pore formation mechanism was also proposed.It was found that the actual temperature of compacts showed an acute climb from 668 to 1244℃ in 166s,while the furnace temperature maintained the linear growth of 5℃/min,which indicated that an obvious thermal explosion（TE）reaction occurred during sintering,and only single-phase TiA13 intermetallic was synthesized in TE products.The open porosity increased from 22.2（green compact）to 32.8% after reactive diffusion sintering at 600℃ and rised to 58.7% after TE,then decreased to 51.2% after high-temperature homogenization at 1100℃.Therefore,TE reaction is the dominated pore formation mechanism of porous TiAl3 intermetallics.The pore evolution in porous TiAl3 intermetallics occurred by the following mechanisms：certain intergranular pores remained among powder particles of green compact,then low-temperature sintering resulted in a further increase in porosity due to the Kirkendall effect.Moreover,TE reaction gave rise to a dramatic volume expansion because of the rapid increase in temperature,and high-temperature sintering caused densification and a slight shrinkage.展开更多
Objective： To explore the association of membrane-associated guanylate kinase inverted 1（MAGI1） with gastric cancer（GC） and the related molecular mechanisms.Methods： The reverse transcription-polymerase chain re...Objective： To explore the association of membrane-associated guanylate kinase inverted 1（MAGI1） with gastric cancer（GC） and the related molecular mechanisms.Methods： The reverse transcription-polymerase chain reaction（RT-PCR） and immunohistochemistry（IHC）were utilized to measure the MAGI1 expression level in GC tissues. Quantitative real-time PCR and Western blotting were used to ensure the MAGI1 expression in GC cell lines. Small hairpin RNA（sh RNA） was applied for knockdown of endogenous MAGI1 in GC cells. MTT assay and colony formation assay, scratch wounding migration assay and transwell chamber migration assay, as well as transwell chamber invasion assay were employed respectively to investigate the GC cell proliferation, migration and invasion in MAGI1-knockdown and control GC cells. The potential molecular mechanism mediated by MAGI1 was studied using Western blotting and RT- PCR.Results： RT-PCR and IHC verified MAGI1 was frequently expressed in matched adjacent noncancerous mucosa compared with GC tissues and the expression of MAGI1 was related to clinical pathological parameters. Functional assays indicated that MAGI1 knockdown significantly promoted GC cell migration and invasion. Further mechanism investigation demonstrated that one pathway of MAGI1 inhibiting migration and invasion was mainly by altering the expression of matrix metalloproteinases（MMPs） and epithelial-mesenchymal transition（EMT）-related molecules via inhibiting MAPK/ERK signaling pathway.Conclusions： MAGI1 was associated with GC clinical pathological parameters and acted as a tumor suppressor via inhibiting of MAPK/ERK signaling pathway in GC.展开更多
Element doping has been proved to be a useful method to correct for the mass bias fractionation when analyzing iron isotope compositions.We present a systematic re-assessment on how the doped nickel may affect the iro...Element doping has been proved to be a useful method to correct for the mass bias fractionation when analyzing iron isotope compositions.We present a systematic re-assessment on how the doped nickel may affect the iron isotope analysis in this study by carrying out several experiments.We find three important factors that can affect the analytical results,including the Ni:Fe ratio in the analyte solutions,the match of the Ni:Fe ratio between the unknown sample and standard solutions,and the match of the Fe concentration between the sample and standard solutions.Thus,caution is required when adding Ni to the analyte Fe solutions before analysis.Using our method,theδ56Fe and δ57Fe values of the USGS standards W-2 a,BHVO-2,BCR-2,AGV-2 and GSP-2 are consistent with the recommended literature values,and the long-term(one year) external reproducibility is better than 0.03 and 0.05‰(2 SD) for δ56Fe and δ57Fe,respectively.Therefore,the analytical method established in our laboratory is a method of choice for high quantity Fe isotope data in geological materials.展开更多
基金supported by grants from the National Key Research and Development Program of China(2021YFD2200502_3)the National Natural Science Foundation of China(32400247 and 32401906)the CAS Project for Young Scientists in Basic Research(YSBR-119)。
文摘The plant cell wall is an extremely complicated natural nanoscale structure composed of cellulose microfibrils embedded in a matrix of noncellulosic polysaccharides,further reinforced by the phenolic compound lignins in some cell types.Such a network formed by the interactions of multiscale polymers actually reflects functional form of the cell wall to meet the requirements of plant cell functionalization.Therefore,how plants assemble cell wall functional structure is fundamental in plant biology and critical for crop trait formation and domestication as well.Due to the lack of effective analytical techniques to characterize this fundamental but complex network,it remains difficult to establish direct links between cell-wall genes and phenotypes.The roles of plant cell walls are often underestimated as indirect.Over the past decades,many genes involved in cell wall biosynthesis,modification,and remodeling have been identified.The application of a variety of state-of-the-art techniques has made it possible to reveal the fine cell wall networks and polymer interactions.Hence,many exciting advances in cell wall biology have been achieved in recent years.This review provides an updated overview of the mechanistic and conceptual insights in cell wall functionality,and prospects the opportunities and challenges in this field.
基金supported by the National Key Research and Development Program of China(No.2023YFC2412300)the National Natural Science Foundation of China(Nos.82025025,U23A6008,U22A20162,and U21A2055)+3 种基金the Natural Science Foun-dation of Hebei Province of China(No.H2022202007)the Full-time Talents Program of Hebei Province of China(No.2020HBQZYC012)the Natural Science Foundation of Tianjin of China(Nos.21JCYBJC01380 and 21JCZDJC01110)the Scientific Research Project of Tianjin Education Commission(No.2022KJ096).
文摘In neurosurgery procedures,cerebrospinal fluid leakage is a commonly encountered complication.Re-constructing skull base defects with patch materials can reduce the risk of cerebrospinal fluid leakage which can lead to serious issues such as infection,meningitis,arachnoiditis,and delayed wound healing.An ideal skull base reconstruction material should not only serve as a leak-proof barrier but also pro-mote skull base bone regeneration.To fulfill this challenge,this research designed and fabricated a Janus orthogonal bilayer nanofiber membrane(OPCL/PG-PCPP).The aligned PCL(APCL)nanofibers were con-stituted as the top layer to resist cerebrospinal fluid leakage,while the perpendicular PCL/gelatin(APG)fibers with calcium polyphosphate encapsulated polydopamine nanoparticles(CPP@PDA,labeled as PCPP)were designed as the bottom layer(APG-PCPP)to facilitate osteoblast migration and osteogenic differen-tiation.Among these,APG-1%PCPP nanofibers demonstrated the most effective induction of osteogenic differentiation in bone marrow mesenchymal stem cells(rBMSCs).Subsequent in vivo animal experi-ments revealed that the bone surface area(BS),bone volume fraction(BV/TV),and number of trabec-ulae(Tb.N)in the APG-1%PCPP group were twice as high as those in the control group,which confirmed the good osteogenic potentials.Therefore,due to its unique leak-proof and osteoinductive properties,the OPCL/PG-PCPP membrane holds promise as an applicable skull base reconstruction material in the field of neurosurgery.
基金the College Students Innovative Practice Fund of Jiangsu University Industrial Center(ZXJG2023047)for funding this research.
文摘Structured design helps to play out the coordination advantage and optimize the performance of electro-chemical reactions.In this work,hierarchical hollow microspheres(Co_(3)S_(4)@NiCo_(2)S_(4)) with unique core-shell heterostructure were successfully prepared through simple template and solvothermal methods.Thanks to the hollow structure,cross-linked nanowire arrays,and in-situ coating of zeolite imidazole framework(ZIF),Co_(3)S_(4)@NiCo_(2)S_(4) demonstrated excellent electrochemical performance with a specific ca-pacitance of up to 2697.7 F g^(-1)at 1 A g^(-1) and cycling stability of 80.5% after 5000 cycles.The covalent organic framework(COF)derived nano carbon,which had undergone secondary calcination and ZnCl_(2) activation,also exhibited excellent double-layer energy storage performance.Compared to a single calci-nation,the incredible increase in capacitance was up to 208.5 times greater,reaching 291.9 F g^(-1)at 1 A g^(-1)while maintaining ultra-high rate performance(81.0%at 20 A g^(-1)).The hybrid supercapacitor,assem-bled with Co_(3)S_(4)@NiCo_(2)S_(4)as the cathode and COF-derived carbon as the anode,exhibited an extremely high energy density(79.7 Wh kg^(-1)at 693.5 W kg^(-1))and excellent cyclic stability(maintained 79.3%after 10,000 cycles of 20 A g^(-1)),further explaining the reliable and practical characteristics.This work provided reference for the structural optimization of transition metal sulfides and the high-temperature activation of COF-derived carbon.
基金co-supported by the National Natural Science Foundation of China(No.51805016)Field Foundation of China(No.JZX7Y20190242012001).
文摘Unmanned Aerial Vehicle(UAV)swarms have been foreseen to play an important role in military applications in the future,wherein they will be frequently subjected to different disturbances and destructions such as attacks and equipment faults.Therefore,a sophisticated robustness evaluation mechanism is of considerable importance for the reliable functioning of the UAV swarms.However,their complex characteristics and irregular dynamic evolution make them extremely challenging and uncertain to evaluate the robustness of such a system.In this paper,a complex network theory-based robustness evaluation method for a UAV swarming system is proposed.This method takes into account the dynamic evolution of UAV swarms,including dynamic reconfiguration and information correlation.The paper analyzes and models the aforementioned dynamic evolution and establishes a comprehensive robustness metric and two evaluation strategies.The robustness evaluation method and algorithms considering dynamic reconfiguration and information correlation are developed.Finally,the validity of the proposed method is verified by conducting a case study analysis.The results can further provide some guidance and reference for the robust design,mission planning and decision-making of UAV swarms.
文摘Objective：The programmed cell death-1 receptor/programmed cell death-1 ligand （PD-1/PD-L1） pathway plays a crucial role in tumor evasion from host immunity.This study was designed to evaluate the association between circulating PD-L1 expression and prognosis in patients with advanced gastric cancer.Methods：Totally 80 advanced gastric cancer patients and 40 health controls from Beijing Cancer Hospital were enrolled in the present study.Circulating PD-L1 expression was tested by enzymelinked immunosorbent assay （ELISA）.The associations between the expression level of PD-L1 and clinicopathological features and prognosis were analyzed statistically.Results：Expression of PD-L1 in advanced gastric cancer patients was significandy up-regulated compared with health people （P=0.006）.The expression of PD-L1 was significantly correlated with differentiation and lymph node metastasis （P=0.026 and P=0.041,respectively）.Although we didn＇t find significant difference in all advanced gastric cancer patients with different PD-L1 expression,the adenocarcinoma patients with higher up-regulated PD-L1 expression had much better prognosis than low expression patients （65.6％ vs.44.7％,P=0.028）.Conclusions：PD-L1 was elevated in advance gastric cancer patients and may play an important role in tumor immune evasion and patients prognosis.
基金supported by grants awarded to Yuanqing Yao by the Key Program of the "Twelfth Five-year plan" of People’s liberation Army(No.BWS11J058)the National High Technology Research and Development Program(SS2015AA020402)
文摘Reliable and accurate pre-implantation genetic diagnosis （PGD） of patient＇s embryos by next-generation sequencing （NGS） is dependent on efficient whole genome amplification （WGA） of a representative biopsy sample. However, the performance of the current state of the art WGA methods has not been evaluated for sequencing. Using low template DNA （15 pg） and single cells, we showed that the two PCR-based WGA systems SurePlex and MALBAC are superior to the REPLI-g WGA multiple displacement amplification （MDA） system in terms of consistent and reproducible genome coverage and sequence bias across the 24 chromosomes, allowing better normalization of test to reference sequencing data. When copy number variation sequencing （CNV-Seq） was applied to single cell WGA products derived by either SurePlex or MALBAC amplification, we showed that known disease CNVs in the range of 3-15 Mb could be reliably and accurately detected at the correct genomic positions. These findings indicate that our CNV-Seq pipeline incorporating either SurePlex or MALBAC as the key initial WGA step is a powerful methodology for clinical PGD to identify euploid embryos in a patient＇s cohort for uterine transplantation,
文摘Objective： To investigate Leucine-rich repeat-containing G protein-coupled receptor 5 （LGR5） expressions in gastric cancer and to evaluate its clinical significance. Methods： LGR5 expression was assessed by immunohistochemistry in 257 gastric cancer patients after surgery. The relationships between LGR5 expression and clinicopathological features and patients prognosis were statistically analyzed. Results： The expression of LGR5 was significantly higher in gastric cancers as a cancer stem cell marker than in adjacent normal tissues （P〈0.001）, and more frequently in patients with intestinal type, well-moderate differentiation and stage I and II （P〈0.05）. Although we found gastric cancer patients with LGR5 positive expression had a poorer prognosis, it didn＇t meet statistical significance （P〉0.05）. LGR5 negative expression was significantly related to the favorable overall survival in stage I and II gastric cancer patients （P〈0.05）. Furthermore, patients with high LGR5 expression tended to be more likely to get progression and have poorer progress-free survival （P〈0.05）. Multivariate Cox regression analysis revealed that LGR5 expression was an independent factor of overall survival for the patients with stage I and II gastric cancer （P〈0.05）. Conclusions： Our results show that LGR5 may play an important role in tumorigenesis and progression and would be a powerful marker to predict the prognosis of patients with stage I and II gastric cancer.
基金co-supported by the Fundamental Research Funds for the Central Universities,China (No. YWF-19-BJJ-340)Field Foundation of China (No.JZX7Y20190242012001)。
文摘With the development of Unmanned Aerial Vehicle(UAV) system autonomy, network communication technology and group intelligence theory, mission execution in the form of a UAV swarm will be an important realization of future applications. Traditional single-UAV mission reliability modeling methods have been unable to meet the requirements of UAV swarm mission reliability modeling. Therefore, the UAV swarm mission reliability modeling and evaluation method is proposed. First, aimed at the interdependence among the multiple layers, a multi-layer network model of a UAV swarm is established. At the same time, based on the system having the following characteristics—using a mission chain to complete the mission and applying the connectivity of the mission network—the mission network model of a UAV swarm is established. Second, vulnerability and connectivity are selected as two indicators to reflect the reliability of the mission, and aimed at random attack and deliberate attack, vulnerability and connectivity evaluation methods are proposed. Finally, the validity and accuracy of the constructed model are verified through simulations,and the model and selected indicators can meet the reliability requirements of the UAV swarm mission. In this way, this study provides quantitative reference for UAV-swarm-related decisionmaking work and supports the development of UAV-swarm-related work.
基金Project supported by the Fundamental Research Funds for the Central Universities(2019ZDPY20)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX21_2199)。
文摘The Cu/CeO_(2)nanoporous composite material was prepared via a one-step and energy-saving method of solution combustion synthesis(SCS).The phase composition,surface morphology and optical characteristics of Cu/CeO_(2)were studied.The results show that the SCS products are composed of cubic fluorite CeO_(2)and Cu.Due to the generation and escape of gas during the synthetic reaction,the SCS CeO_(2)shows porous structure,in which the mesopores(diameter 10-17 nm)nest in the wall of large pores(diameter80-300 nm).X-ray photoelectron spectroscopy(XPS)outcomes indicate that the oxygen vacancy concentration of CeO_(2)increases(18.97%-30.93%)with the increase of Cu concentration.The decoration of Cu greatly enhances the catalytic activity of CeO_(2)nanomaterials.30 wt%Cu/CeO_(2)composite material shows the best photocatalytic activities for the degradation of methyl orange(MO)(95.99%),which is about 4.3times that of CeO_(2)at the same time(120 min).UV-vis diffuse reflectance spectroscopy(DRS)results show that the semiconductor band gap is reduced with the addition of metallic Cu,which leads to the enhancement of photocatalytic activity.The free radical trapping experiments demonstrate that·O_(2)-and h+are the main active species in the photocatalytic degradation of MO.Based on the above results,a hypothesized mechanism for enhanced photocatalysis of Cu/CeO_(2)nanomaterials was proposed:the porous structure provides more reactive sites and channels for mass transfer,and the presence of metallic Cu improves the oxygen vacancy concentration of CeO_(2)and then promotes charge-carrier separation,which helps enhance the photocatalytic performance of Cu/CeO_(2).
文摘This paper gives the truncated version of the Minpert method:the incomplete minimum perturbation algorithm(IMinpert).It is based on an incomplete orthogonal-ization of the Krylov vectors in question,and gives a quasi-minimum backward error solution over the Krylov subspace.In order to make the practical implementation of IMinpert easy and convenient,we give another approximate version of the IMinpert method:A-IMinpert.Theoretical properties of the latter algorithm are discussed.Nu-merical experiments are reported to show the proposed method is effective in practice and is competitive with the Minpert algorithm.
基金Project supported by the Key R&D Project of Hebei Province(18214321)the Research Foundation of Hengshui University for High-level Talents(2019GC10)+1 种基金National Innovation and Entrepreneurship Training Program for College Students(202010101001)the Science Technology Program of Hengshui city(2018011002Z)。
文摘Here,we report a series of Bi^(3+)-doped Ba_(2)Y_(1-x)Sc_(x)NbO_(6)(0≤x≤1.0 mol)phosphors by using the traditional high temperature solid-state reaction.To achieve the structural and photoluminescent(PL)information,several experimental characterizations and theoretical calculations were carried out,including X-ray diffraction(XRD),Rietveld refinement,UV-visible diffuse reflectance and PL spectra,temperature dependent PL spectra,and density functional theo retical(DFT)calculations.The XRD results show that the Bi^(3+)-doped Ba_(2)Y_(1-x)Sc_(x)NbO_(6)samples belong to the double-perovskite phase with a cubic space group of Fm3 m,and the diffraction positions shift toward high diffraction angle when the larger Y^(3+)ions are gradually replaced by the smaller Sc^(3+)ions.In addition,the refined XRD findings show that the Bi^(3+)ions tend to substitute the Y^(3+)and Sc^(3+)sites in the Bi^(3+)-doped Ba_(2)Y_(1-x)Sc_(x)NbO_(6)0<x<1.0 mol)solid solutions.The PL spectra show that the emission positions of the solid solution samples tune from446 to 497 nm with the increase of Sc^(3+) content,which can be attributed to the modification of crystal field strength around Bi^(3+)ions.Moreover,there is energy transfer from the Ba_(2)YNbO_(6)host to Bi^(3+)ions,which is dominated by a resonant type via a dipole-quadrupole(d-q)interaction.The Ba_(2)Y_(0.6)Sc_(0.4)NbO_(6):0.02 molBi^(3+)shows the strongest PL intensity under 365 nm excitation,with the best quantum efficiency(QE)of 68%,and it keeps 60%of the room temperature emission intensity when the temperature increases to 150℃,meaning that the Ba_(2)Y_(0.6)Sc_(0.4)NbO_(6):Bi^(3+)features excellent thermal quenching of luminescence.By combining this optimal sample with a commercial red-emitting Sr_(2)Si_(5)N_(8):Eu^(2+)phosphor,and a commercial 365 nm UV LED chip,a white LED device,with the color temperature(CT)of 3678 K,color rendering index(CRI)of 67.9,and CIE coordinates at(0.371,0.376),is achieved.
基金financially supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholarsthe State Education Ministry(No.1001603-C)+3 种基金"521 Talents Training Plan" in ZSTUthe National Natural Science Foundation of China(Nos.51373155 and 51133006)the Natural Science Foundation of Zhejiang Province(No.LY13B030009)the Innovative Program for Graduate Students of Zhejiang Sci-Tech University(No.2013YSPY15)
文摘The N-doped bismuth tungstate （BizWOt） photocatalysts with high visible light activity were prepared by the hydrothermal method using urea as a nitrogen source. The as-prepared N-doped Bi2WO6 samoles were characterized by X-ray diffraction, scanning electron microscopy, specific surface area, photocurrent analysis, and UV-Vis diffuse re- flectrance spectroscopy. The photocatalytic activity was evaluated by photocatalytic degradation of rhodamine B （RhB） solution under visible light irradiation. The photocatalytic mechanisms were analyzed by active species trapping experi- ments which revealed that the holes were the main active species of N-doped BizWO6 products in aqueous solution under visible light irradiation, rather than .OH and O-. With the assistance of H202, the photocatalytic activity for degradation of RhB could be further improved because H202 reacted with conduction band electrons to generate more hydroxyl radicals. KEY WORDS：
基金supported by the Fundamental Research Funds for the Central Universities(2017XKQY006)
文摘Porous TiAl3 intermetallics were fabricated through vacuum reactive sintering from Ti-75A1 at.% elemental powder mixture.The phase compositions,expansion behaviors,pore characteristics and microstructure evolution of TiAl3 intermetallics were investigated,and the pore formation mechanism was also proposed.It was found that the actual temperature of compacts showed an acute climb from 668 to 1244℃ in 166s,while the furnace temperature maintained the linear growth of 5℃/min,which indicated that an obvious thermal explosion（TE）reaction occurred during sintering,and only single-phase TiA13 intermetallic was synthesized in TE products.The open porosity increased from 22.2（green compact）to 32.8% after reactive diffusion sintering at 600℃ and rised to 58.7% after TE,then decreased to 51.2% after high-temperature homogenization at 1100℃.Therefore,TE reaction is the dominated pore formation mechanism of porous TiAl3 intermetallics.The pore evolution in porous TiAl3 intermetallics occurred by the following mechanisms：certain intergranular pores remained among powder particles of green compact,then low-temperature sintering resulted in a further increase in porosity due to the Kirkendall effect.Moreover,TE reaction gave rise to a dramatic volume expansion because of the rapid increase in temperature,and high-temperature sintering caused densification and a slight shrinkage.
基金supported by the Young Talents of Science and Technology Support Project of Colleges and Universities of Inner Mongolia Autonomous Region (NJYT-12-B21, 2012)the Great Project of the Affiliated Hospital of Inner Mongolia Medical University (No. NYFY ZD 2012014)+3 种基金the National Natural Science Foundation of China (No. 81260363)Beijing Municipal Administration of Hospitals’ Youth Programme (No. QML20151003)the Project supported by National Science and Technology Ministry (No. 2014BAI09B02)Beijing Municipal Administration of Hospitals Clinical Medicine Development of Special Funding Support (No. ZYLX201701)
文摘Objective： To explore the association of membrane-associated guanylate kinase inverted 1（MAGI1） with gastric cancer（GC） and the related molecular mechanisms.Methods： The reverse transcription-polymerase chain reaction（RT-PCR） and immunohistochemistry（IHC）were utilized to measure the MAGI1 expression level in GC tissues. Quantitative real-time PCR and Western blotting were used to ensure the MAGI1 expression in GC cell lines. Small hairpin RNA（sh RNA） was applied for knockdown of endogenous MAGI1 in GC cells. MTT assay and colony formation assay, scratch wounding migration assay and transwell chamber migration assay, as well as transwell chamber invasion assay were employed respectively to investigate the GC cell proliferation, migration and invasion in MAGI1-knockdown and control GC cells. The potential molecular mechanism mediated by MAGI1 was studied using Western blotting and RT- PCR.Results： RT-PCR and IHC verified MAGI1 was frequently expressed in matched adjacent noncancerous mucosa compared with GC tissues and the expression of MAGI1 was related to clinical pathological parameters. Functional assays indicated that MAGI1 knockdown significantly promoted GC cell migration and invasion. Further mechanism investigation demonstrated that one pathway of MAGI1 inhibiting migration and invasion was mainly by altering the expression of matrix metalloproteinases（MMPs） and epithelial-mesenchymal transition（EMT）-related molecules via inhibiting MAPK/ERK signaling pathway.Conclusions： MAGI1 was associated with GC clinical pathological parameters and acted as a tumor suppressor via inhibiting of MAPK/ERK signaling pathway in GC.
基金This work was supported by National Nature Science Foundation of China(Grant Numbers 41776067 and 41630968).
文摘Element doping has been proved to be a useful method to correct for the mass bias fractionation when analyzing iron isotope compositions.We present a systematic re-assessment on how the doped nickel may affect the iron isotope analysis in this study by carrying out several experiments.We find three important factors that can affect the analytical results,including the Ni:Fe ratio in the analyte solutions,the match of the Ni:Fe ratio between the unknown sample and standard solutions,and the match of the Fe concentration between the sample and standard solutions.Thus,caution is required when adding Ni to the analyte Fe solutions before analysis.Using our method,theδ56Fe and δ57Fe values of the USGS standards W-2 a,BHVO-2,BCR-2,AGV-2 and GSP-2 are consistent with the recommended literature values,and the long-term(one year) external reproducibility is better than 0.03 and 0.05‰(2 SD) for δ56Fe and δ57Fe,respectively.Therefore,the analytical method established in our laboratory is a method of choice for high quantity Fe isotope data in geological materials.
