The retina,a crucial neural tissue,is responsible for transforming light signals into visual information,a process that necessitates a significant amount of energy.Mitochondria,the primary powerhouses of the cell,play...The retina,a crucial neural tissue,is responsible for transforming light signals into visual information,a process that necessitates a significant amount of energy.Mitochondria,the primary powerhouses of the cell,play an integral role in retinal physiology by fulfilling the high-energy requirements of photoreceptors and secondary neurons through oxidative phosphorylation.In a healthy state,mitochondria ensure proper visual function by facilitating efficient conversion and transduction of visual signals.However,in retinal degenerative diseases,mitochondrial dysfunction significantly contributes to disease progression,involving a decline in membrane potential,the occurrence of DNA mutations,increased oxidative stress,and imbalances in quality-control mechanisms.These abnormalities lead to an inadequate energy supply,the exacerbation of oxidative damage,and the activation of cell death pathways,ultimately resulting in neuronal injury and dysfunction in the retina.Mitochondrial transplantation has emerged as a promising strategy for addressing these challenges.This procedure aims to restore metabolic activity and function in compromised cells through the introduction of healthy mitochondria,thereby enhancing the cellular energy production capacity and offering new strategies for the treatment of retinal degenerative diseases.Although mitochondrial transplantation presents operational and safety challenges that require further investigation,it has demonstrated potential for reviving the vitality of retinal neurons.This review offers a comprehensive examination of the principles and techniques underlying mitochondrial transplantation and its prospects for application in retinal degenerative diseases,while also delving into the associated technical and safety challenges,thereby providing references and insights for future research and treatment.展开更多
The practical application of lithium-sulfur(Li-S)batteries is hindered by the sluggish redox kinetics of sulfur,significant volume expansion,and the shuttle effect of lithium polysulfides(LiPSs).To address these chall...The practical application of lithium-sulfur(Li-S)batteries is hindered by the sluggish redox kinetics of sulfur,significant volume expansion,and the shuttle effect of lithium polysulfides(LiPSs).To address these challenges,this study utilizes hollow carbon spheres(HCS)as a matrix,incorporating a heterojunction of transition metal sulfides(CoS_(2)/MoS_(2))as the sulfur host.The HCS,with their ultrahigh specific surface area,effectively mitigate structural damage to the cathode caused by sulfur’s volume expansion during charge and discharge cycles.Meanwhile,the CoS_(2)/MoS_(2)heterojunction provides abundant chemical adsorption and reaction sites,which accelerate the redox kinetics of sulfur and alleviating the shuttle effect of LiPSs.Density functional theory(DFT)calculations reveal that the coupling effect at the CoS_(2)/MoS_(2)heterointerface significantly enhances charge transfer and adsorption interactions between CoS_(2)/MoS_(2)and LiPSs.Experimental results demonstrate that Li-S batteries with S/CoS_(2)/MoS_(2)@HCS composites as the cathode exhibit an exceptionally low capacity decay rate of only 0.023%per cycle after 1200 cycles at 2.0 C.Even with high sulfur loading(7.9 mg cm^(−2))and a low electrolyte-to-sulfur(E/S)ratio(6.0μL mg^(−1)),the battery achieves an outstanding areal capacity of 6.86 mA h cm^(−2).This study develops a highly efficient CoS_(2)/MoS_(2)heterojunction within HCS for the adsorption and conversion of LiPSs,providing valuable insights into the design of high-performance cathode materials for Li-S batteries.展开更多
Besides the Indonesian throughflow(ITF), the South China Sea throughflow(SCSTF) also contributes to the water transport from the Pacific to the Indian Ocean. However, this South China Sea(SCS) branch at the Karimata S...Besides the Indonesian throughflow(ITF), the South China Sea throughflow(SCSTF) also contributes to the water transport from the Pacific to the Indian Ocean. However, this South China Sea(SCS) branch at the Karimata Strait is poorly observed until 2007, even though its importance has been suggested by numerical studies for decades. In this paper, we review the nearly 10-year field measurement in the Karimata Strait by the execution of the projects of "SCS-Indonesian Seas Transport/Exchange(SITE) and Impacts on Seasonal Fish Migration" and "The Transport, Internal Waves and Mixing in the Indonesian Throughflow regions(TIMIT) and Impacts on Marine Ecosystem", which extend the observations from the western Indonesian seas to the east to include the main channels of the ITF, is introduced. Some major achievements from these projects are summarized.展开更多
We simulate the gas-atomization process of a close-coupled annular nozzle for vacuum induction gas atomization at a three-dimensional scale.Moreover,the relationship between the simulated droplet type and experimental...We simulate the gas-atomization process of a close-coupled annular nozzle for vacuum induction gas atomization at a three-dimensional scale.Moreover,the relationship between the simulated droplet type and experimentally metallic powder is established by comparing the morphology of droplets with powders.Herein,the primary atomization process is described by the volume-of-fluid(VOF)approach,whereas the prediction of powder diameter after secondary atomization is realized by the VOF-Lagrangian method.In addition,to completely reflect the breaking and deformation process of the metallic flow,we employ the VOF model to simulate the secondary atomization process of a single ellipsoidal droplet.The results show that the primary atomization process includes the formation of surface liquid film,appearance of serrated ligaments,and shredding of ligaments.Further,gas recirculation zone plays an important role in formation of the umbrella-shaped liquid film.The secondary atomization process is divided into droplet convergence and dispersion stages,and the predicted powder diameter is basically consistent with the experiment.In general,the four main powder shapes are formed by the interaction of five different typical droplets.展开更多
Tylorrhynchus heterochaetus is a widespread benthic polychaete worm found in coastal brackish waters of the west Pacific.It has high ecological and economic value as a biomarker of water quality and as a high-quality ...Tylorrhynchus heterochaetus is a widespread benthic polychaete worm found in coastal brackish waters of the west Pacific.It has high ecological and economic value as a biomarker of water quality and as a high-quality feed in aquaculture and fisheries and is considered a delicacy in some areas of Asia.However,it has experienced a marked reduction in recent years due to overexploitation as well as changes in the environment and climate.Here,to comprehensively understand its genetic background and thus provide insights for better conservation and utilization of this species,we assessed the genetic variability and demographic history of T.heterochaetus individuals sampled from eight locations along the coasts of southeast China and north Vietnam based on mitochondrial cytochrome c oxidase I(COI)sequences.We observed high haplotype diversity(Hd),with an average of 0.926,but relatively low nucleotide diversity(π),with a mean of 0.032 across all samples.A total of 94 polymorphic sites and 85 haplotypes were identified among 320 individuals.The pairwise genetic distances among haplotypes ranged from 0.001 to 0.067,with the high intraspecific divergence possibly reflecting geographic isolation and gene pool fragmentation.Significant genetic structures were revealed among the studied locations;specifically,the eight locations could be treated as six genetically different populations based on pairwiseΦST results(0.026–0.951,P<0.01).A significant pattern of isolation-by-distance was detected between the genetic and geographic distances(r=0.873,P=0.001).Three geographic lineages were defined based on phylogenetic tree and network analyses of COI haplotypes.AMOVA results indicated that genetic variations mainly occurred among the three lineages(89.96%).Tests of neutrality and mismatch distribution suggested that T.heterochaetus underwent recent population expansion.These results provide the first report on the genetic status of T.heterochaetus and will be valuable for the management of genetic resources and better understanding of the ecology and evolution in this species.展开更多
BACKGROUND:Whether splenectomy can be performed simultaneously during liver transplantation in patients with end-stage liver diseases complicated by hypersplenism remains controversial.This study aimed to compare the ...BACKGROUND:Whether splenectomy can be performed simultaneously during liver transplantation in patients with end-stage liver diseases complicated by hypersplenism remains controversial.This study aimed to compare the impact of simultaneous splenectomy on high-and low-risk liver transplant patients with end-stage liver diseases and severe hypersplenism.METHODS:Forty-two patients with end-stage liver diseases complicated by severe hypersplenism who had undergone orthotopic liver transplantation were enrolled in this study.Splenectomy was performed in 19 of the patients.The 42 patients were grouped according to the risk of liver diseases and operations they received.Patients were considered to be at high-risk if they had at least one of the following conditions:preoperative prothrombin time>5 seconds,portal vein thrombosis,and severe perisplenitis.High-risk patients who had undergone splenectomy were classified into group A,whereas high-risk patients who had not undergone splenectomy were classified into group B.Low-risk patients who had undergone splenectomy were classified into group C,and low-risk patients who had spleen preservation were classified into group D.Operative time,intraoperative blood loss,postoperative bleeding,pulmonary infection,perioperative mortality,and postoperative platelet recovery were analyzed.RESULTS:Operative time and intraoperative blood loss were greater in group A than in groups B-D(P<0.01),but there was no significant difference between groups C and D(P>0.05).In group A,3 patients had postoperative bleeding,5 had pulmonary infection,and 2 had perioperative mortality,which was higher than any other group,but postoperative bleeding,pulmonary infection,and perioperative mortality were similar to those in groups C and D.In patients undergoing simultaneous splenectomy,platelet counts recovered within 6 months after surgery.Thrombocytopenia was sustained in 3 of the 23 patients who did not undergo simultaneous splenectomy.CONCLUSION:Splenectomy should be avoided during orthotopic liver transplantation in high-risk patients,but this procedure does not increase the operative risk in low-risk patients and may be a valuable method to ensure good postoperative platelet recovery.展开更多
The paper aims at modeling and simulating the atomization process of the close-coupled ring-hole nozzle in vacuum induction gas atomization(VIGA)for metallic powder production.First of all,the primary atomization of t...The paper aims at modeling and simulating the atomization process of the close-coupled ring-hole nozzle in vacuum induction gas atomization(VIGA)for metallic powder production.First of all,the primary atomization of the ring-hole nozzle is simulated by the volume of fluid(VOF)coupled large eddy simulation(LES)model.To simulate the secondary atomization process,we use the method of selecting the droplet sub-model and the VOF model.The results show that the ring-hole nozzle forms a gas recirculation zone at the bottom of the delivery tube,which is the main reason for the formation of an annular liquid film during the primary atomization.In addition,the primary atomization process of the ring-hole nozzle consists of three stages:the formation of the serrated liquid film tip,the appearance and shedding of the ligaments,and the fragmentation of ligaments.At the same time,the primary atomization mainly forms spherical droplets and long droplets,but only the long droplets can be reserved and proceed to the secondary atomization.Moreover,increasing the number of ring holes from 18 to 30,the mass median diameter(MMD,d_(50))of the primary atomized droplets decreases first and then increases,which is mainly due to the change of the thickness of the melt film.Moreover,the secondary atomization of the ring-hole nozzles is mainly in bag breakup mode and multimode breakup model,and bag breakup will result in the formation of hollow powder,which can be avoided by increasing the gas velocity.展开更多
The adsorption behavior of CO_2, CH_4 and their mixtures in bituminous coal was investigated in this study. First, a bituminous coal model was built through molecular dynamic(MD) simulations, and it was confirmed to b...The adsorption behavior of CO_2, CH_4 and their mixtures in bituminous coal was investigated in this study. First, a bituminous coal model was built through molecular dynamic(MD) simulations, and it was confirmed to be reasonable by comparing the simulated results with the experimental data. Grand Canonical Monte Carlo(GCMC)simulations were then carried out to investigate the single and binary component adsorption of CO_2 and CH_4with the built bituminous coal model. For the single component adsorption, the isosteric heat of CO_2 adsorption is greater than that of CH_4 adsorption. CO_2 also exhibits stronger electrostatic interactions with the heteroatom groups in the bituminous coal model compared with CH_4, which can account for the larger adsorption capacity of CO_2 in the bituminous coal model. In the case of binary adsorption of CO_2 and CH_4mixtures, CO_2 exhibits the preferential adsorption compared with CH_4 under the studied conditions. The adsorption selectivity of CO_2 exhibited obvious change with increasing pressure. At lower pressure, the adsorption selectivity of CO_2 shows a rapid decrease with increasing the temperature, whereas it becomes insensitive to temperature at higher pressure. Additionally, the adsorption selectivity of CO_2 decreases gradually with the increase of the bulk CO_2 mole fraction and the depth of CO_2 injection site.展开更多
The CaLaGa3O7：Eu3＋ phosphor was prepared by a chemical co-precipitation method. Field emission scanning electron microscopy （FE-SEM）, laser particle size analysis, X-ray diffraction （XRD）, photoluminescence （PL...The CaLaGa3O7：Eu3＋ phosphor was prepared by a chemical co-precipitation method. Field emission scanning electron microscopy （FE-SEM）, laser particle size analysis, X-ray diffraction （XRD）, photoluminescence （PL）, and cathodoluminescence （CL） spectra were util- ized to characterize the synthesized phosphor. The results revealed that the phosphor was composed of microspheres with a slight agglomerate phenomenon and was spherically shaped. The average grain size was about 1.0 μm. Eu3＋ ions, as luminescent centers, substituted La3＋ ions into the single crystal lattice of CaLaGa307 with the sites of Cs. Although the CL spectrum was greatly different from the PL spectrum, it had the strongest red emission corresponding to the 5D0→7F2 transition of Eu3＋. Under the excitation of UV light （287 nm） and electron beams （1.0-7.0 kV）, the chromaticity coordinates of the phosphor were found to be in the nearly red and orange light regions, respec- tively.展开更多
BTG1 （B-cell Translocation Gene 1） , a member of the BTG / TOB （Transducer of ErbB-2） family of anti-proliferation factors,has been proven to have an unfavorable effect on muscle fiber growth in several species. T...BTG1 （B-cell Translocation Gene 1） , a member of the BTG / TOB （Transducer of ErbB-2） family of anti-proliferation factors,has been proven to have an unfavorable effect on muscle fiber growth in several species. The porcine BTG1 gene was cloned and its 5＇ flanking promoter region sequence, and characterized the expression patterns in different tissues of adult pigs and in fetal skeletal muscle at different developmental stages in two breeds. The tissue distribution pattern analyses revealed that the mRNA of porcine BTG1 was ubiquitously expressed in the six tissues of both Landrace and Tongcheng pigs. Real-time quantitative reverse transcriptase-PCR results showed that BTG1 mRNA expression levels were significantly different among the three fetal ages in Tongcheng pigs,while no significant differences were found among the three ages in Landrace pigs. Furthermore,the expression of BTG1 in Landrace pigs was significantly lower than in Tongcheng pigs at all three ages. The temporal expression profiles of the BTG1 gene in mouse myoblast C 2 C 12 cells were shown to be consistent with those of the myogenin gene. A single nucleotide polymorphism （SNP） ,g. 281C 〉 T,was identified in the 3＇UTR and allele frequencies were detected in seven pig breed populations. Significant associations were found between the g. 281C 〉 T polymorphism and growth and meat quality traits. Our results indicate that the porcine BTG1 gene could play a potential role in markerassisted selection and as such may be a gene of economic importance.展开更多
Anaerobic treatment is the core technology for resource and energy recovery from source-separated domestic bio-wastes. The higher efficiency of an improved upflow solid reactor（IUSR） designed in this study was demon...Anaerobic treatment is the core technology for resource and energy recovery from source-separated domestic bio-wastes. The higher efficiency of an improved upflow solid reactor（IUSR） designed in this study was demonstrated in the treatment of concentrated black water and kitchen waste. The highest methane production of 48 L/person/day was achieved at the hydraulic retention time（HRT） of 7 days, while the other measures of performance at the HRT of 8.3 days were better than at the HRT of 7 or 10 days, achieving a methane production of 43 L/person/day, removal of total chemical oxygen demand（TCOD）of 89%, removal of soluble chemical oxygen demand（SCOD） of 92%, and conversion of chemical oxygen demand（COD） to methane of 71%. It is not recommended to decrease HRT lower than 7 days due to the instability of the initial period. The concentrations of volatile fatty acids（VFAs） in the IUSR were less than 10 mg/L, indicating that the anaerobic process was stable. Sludge bed development showed that sludge bed with high microbial activity was formed in the bottom and that the precipitation zone of effluents formed should preferably occupy 30% of the height of the IUSR. The effluents of the IUSR could be used for irrigation in agriculture in combination with a settling tank accompanied by disinfection to remove solids and pathogens.展开更多
Underwater image enhancement aims to restore a clean appearance and thus improves the quality of underwater degraded images.Current methods feed the whole image directly into the model for enhancement.However,they ign...Underwater image enhancement aims to restore a clean appearance and thus improves the quality of underwater degraded images.Current methods feed the whole image directly into the model for enhancement.However,they ignored that the R,G and B channels of underwater degraded images present varied degrees of degradation,due to the selective absorption for the light.To address this issue,we propose an unsupervised multi-expert learning model by considering the enhancement of each color channel.Specifically,an unsupervised architecture based on generative adversarial network is employed to alleviate the need for paired underwater images.Based on this,we design a generator,including a multi-expert encoder,a feature fusion module and a feature fusion-guided decoder,to generate the clear underwater image.Accordingly,a multi-expert discriminator is proposed to verify the authenticity of the R,G and B channels,respectively.In addition,content perceptual loss and edge loss are introduced into the loss function to further improve the content and details of the enhanced images.Extensive experiments on public datasets demonstrate that our method achieves more pleasing results in vision quality.Various metrics(PSNR,SSIM,UIQM and UCIQE) evaluated on our enhanced images have been improved obviously.展开更多
Regulating the catalyst electronic structure is critical for improving the adsorption and catalytic conversion of lithium polysulfides(LiPSs)in lithium-sulfur batteries(Li-S),yet which has been overlooked in current s...Regulating the catalyst electronic structure is critical for improving the adsorption and catalytic conversion of lithium polysulfides(LiPSs)in lithium-sulfur batteries(Li-S),yet which has been overlooked in current studies.In this work,structurally defined Ag_(30)Pd_(4)nanoclusters were loaded onto reduced graphene oxide(Ag_(30)Pd_(4)/rGO)as a modification material for polypropylene(PP)separators to elucidate the catalytic activity towards lithium polysulfides and the impact on the electrochemical properties to lithium sulfur batteries.This unique d-πcombination promotes charge transfer,influences overall charge states,and further enhances adsorption energies in potential reaction pathways with lithium polysulfides.Consequently,the Ag_(30)Pd_(4)/rGO/PP modified batteries exhibited an exceptionally low-capacity decay rate of 0.026%per cycle at 1.0C over 1000 stable cycles and 9.75 mAh cm^(-2)excellent performance even with lean electrolyte and high sulfur loading(9.7 mg cm^(-2)).This study paves a path for employing ultrasmall bimetallic nanoclusters to promote the polysulfides redox kinetics hence boosting the lithiumsulfur battery performance.展开更多
Poly（p-phenylene） （PPP） films have been electrochemically deposited on mirrorlike stainless steel （SS） electrode surfaces by direct oxidation of benzene in boron trifluoride diethyl etherate （BFEE） solutions a...Poly（p-phenylene） （PPP） films have been electrochemically deposited on mirrorlike stainless steel （SS） electrode surfaces by direct oxidation of benzene in boron trifluoride diethyl etherate （BFEE） solutions at a constant applied potential of 1.7 V （versus Ag/AgCl）. The chain conformations of as-grown PPP films have been studied by Raman spectroscopy. The results demonstrated that high synthesis temperature favors the formation of planar PPP, and the conformation of planar PPP can be changed into torsional PPP by cooling treatment.展开更多
Anterior cervical decompression and fusion(ACDF)treatment for cervical spondylosis has been more than half a century,and achieved good clinical results.However,with the continuous extension of follow-up time,the fusio...Anterior cervical decompression and fusion(ACDF)treatment for cervical spondylosis has been more than half a century,and achieved good clinical results.However,with the continuous extension of follow-up time,the fusion segment-associated postoperative complications emerged gradually.Reserved cervical stability and activity,the concept of non-fusion was born.As a non-fusion technique,cervical artificial disc replacement(CADR)developed rapidly.With the continuous development of artificial prosthesis materials and design concepts,and specification and proficiency of surgical procedures,CADR has achieved better short and mid-term clinical efficacy than ACDF.Compared with ACDF,the main advantages of CADR are that the postoperative recovery is quick,the activity and stability of cervical vertebra are maintained,the height of cervical intervertebral space is restored,and the stress of adjacent segments and the rate of surgical renovation are reduced.In clinical work,as an emerging technology,CADR requires spine surgeons to control the surgical indications,contraindications,and patients'conditions strictly.This article reviews the research progress of CADR in order to provide new ideas for clinical treatment of cervical spondylosis.展开更多
基金supported by the National Natural Science Foundation of China,Nos.8247041526,81570864,82171053(to GYL)。
文摘The retina,a crucial neural tissue,is responsible for transforming light signals into visual information,a process that necessitates a significant amount of energy.Mitochondria,the primary powerhouses of the cell,play an integral role in retinal physiology by fulfilling the high-energy requirements of photoreceptors and secondary neurons through oxidative phosphorylation.In a healthy state,mitochondria ensure proper visual function by facilitating efficient conversion and transduction of visual signals.However,in retinal degenerative diseases,mitochondrial dysfunction significantly contributes to disease progression,involving a decline in membrane potential,the occurrence of DNA mutations,increased oxidative stress,and imbalances in quality-control mechanisms.These abnormalities lead to an inadequate energy supply,the exacerbation of oxidative damage,and the activation of cell death pathways,ultimately resulting in neuronal injury and dysfunction in the retina.Mitochondrial transplantation has emerged as a promising strategy for addressing these challenges.This procedure aims to restore metabolic activity and function in compromised cells through the introduction of healthy mitochondria,thereby enhancing the cellular energy production capacity and offering new strategies for the treatment of retinal degenerative diseases.Although mitochondrial transplantation presents operational and safety challenges that require further investigation,it has demonstrated potential for reviving the vitality of retinal neurons.This review offers a comprehensive examination of the principles and techniques underlying mitochondrial transplantation and its prospects for application in retinal degenerative diseases,while also delving into the associated technical and safety challenges,thereby providing references and insights for future research and treatment.
基金supported in part by the Institute for Advanced Study of Central South University and the High Performance Computing Center of Central South University。
文摘The practical application of lithium-sulfur(Li-S)batteries is hindered by the sluggish redox kinetics of sulfur,significant volume expansion,and the shuttle effect of lithium polysulfides(LiPSs).To address these challenges,this study utilizes hollow carbon spheres(HCS)as a matrix,incorporating a heterojunction of transition metal sulfides(CoS_(2)/MoS_(2))as the sulfur host.The HCS,with their ultrahigh specific surface area,effectively mitigate structural damage to the cathode caused by sulfur’s volume expansion during charge and discharge cycles.Meanwhile,the CoS_(2)/MoS_(2)heterojunction provides abundant chemical adsorption and reaction sites,which accelerate the redox kinetics of sulfur and alleviating the shuttle effect of LiPSs.Density functional theory(DFT)calculations reveal that the coupling effect at the CoS_(2)/MoS_(2)heterointerface significantly enhances charge transfer and adsorption interactions between CoS_(2)/MoS_(2)and LiPSs.Experimental results demonstrate that Li-S batteries with S/CoS_(2)/MoS_(2)@HCS composites as the cathode exhibit an exceptionally low capacity decay rate of only 0.023%per cycle after 1200 cycles at 2.0 C.Even with high sulfur loading(7.9 mg cm^(−2))and a low electrolyte-to-sulfur(E/S)ratio(6.0μL mg^(−1)),the battery achieves an outstanding areal capacity of 6.86 mA h cm^(−2).This study develops a highly efficient CoS_(2)/MoS_(2)heterojunction within HCS for the adsorption and conversion of LiPSs,providing valuable insights into the design of high-performance cathode materials for Li-S batteries.
基金The National Key Research and Development Program of China under contract No.2016YFC1402604the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)under contract No.2015ASKJ01+4 种基金the SOA Program on Global Change and Air-Sea Interactions under contract Nos GASI-IPOVAI-03,GASI-IPOVAI-02 and GASI-IPOVAI-01-02the National Natural Science Foundation of China under contract Nos 40476025,41506036 and 41876027the NSFC-Shandong Joint Fund for Marine Science Research Centers under contract No.U1606405the Office of Naval Research of United States under contract No.N00014-08-01-0618the China-Indonesia Maritime Cooperation Fund
文摘Besides the Indonesian throughflow(ITF), the South China Sea throughflow(SCSTF) also contributes to the water transport from the Pacific to the Indian Ocean. However, this South China Sea(SCS) branch at the Karimata Strait is poorly observed until 2007, even though its importance has been suggested by numerical studies for decades. In this paper, we review the nearly 10-year field measurement in the Karimata Strait by the execution of the projects of "SCS-Indonesian Seas Transport/Exchange(SITE) and Impacts on Seasonal Fish Migration" and "The Transport, Internal Waves and Mixing in the Indonesian Throughflow regions(TIMIT) and Impacts on Marine Ecosystem", which extend the observations from the western Indonesian seas to the east to include the main channels of the ITF, is introduced. Some major achievements from these projects are summarized.
基金Project supported by the National Natural Science Foundation of China(Grant No.51975240)the Open Fund of State Key Laboratory of Advanced Forming Technology and Equipment(Grant No.SKL2019006)。
文摘We simulate the gas-atomization process of a close-coupled annular nozzle for vacuum induction gas atomization at a three-dimensional scale.Moreover,the relationship between the simulated droplet type and experimentally metallic powder is established by comparing the morphology of droplets with powders.Herein,the primary atomization process is described by the volume-of-fluid(VOF)approach,whereas the prediction of powder diameter after secondary atomization is realized by the VOF-Lagrangian method.In addition,to completely reflect the breaking and deformation process of the metallic flow,we employ the VOF model to simulate the secondary atomization process of a single ellipsoidal droplet.The results show that the primary atomization process includes the formation of surface liquid film,appearance of serrated ligaments,and shredding of ligaments.Further,gas recirculation zone plays an important role in formation of the umbrella-shaped liquid film.The secondary atomization process is divided into droplet convergence and dispersion stages,and the predicted powder diameter is basically consistent with the experiment.In general,the four main powder shapes are formed by the interaction of five different typical droplets.
基金supported by the IndustryAcademic Research Cooperation Program of Academician Workstation of Guangdong Province(2013B090400017)Natural Science Foundation of Guangdong Province(2016A030307036)Yangfan Innovative&Entrepreneurial Research Team Project for Guangdong Province(201312H10)
文摘Tylorrhynchus heterochaetus is a widespread benthic polychaete worm found in coastal brackish waters of the west Pacific.It has high ecological and economic value as a biomarker of water quality and as a high-quality feed in aquaculture and fisheries and is considered a delicacy in some areas of Asia.However,it has experienced a marked reduction in recent years due to overexploitation as well as changes in the environment and climate.Here,to comprehensively understand its genetic background and thus provide insights for better conservation and utilization of this species,we assessed the genetic variability and demographic history of T.heterochaetus individuals sampled from eight locations along the coasts of southeast China and north Vietnam based on mitochondrial cytochrome c oxidase I(COI)sequences.We observed high haplotype diversity(Hd),with an average of 0.926,but relatively low nucleotide diversity(π),with a mean of 0.032 across all samples.A total of 94 polymorphic sites and 85 haplotypes were identified among 320 individuals.The pairwise genetic distances among haplotypes ranged from 0.001 to 0.067,with the high intraspecific divergence possibly reflecting geographic isolation and gene pool fragmentation.Significant genetic structures were revealed among the studied locations;specifically,the eight locations could be treated as six genetically different populations based on pairwiseΦST results(0.026–0.951,P<0.01).A significant pattern of isolation-by-distance was detected between the genetic and geographic distances(r=0.873,P=0.001).Three geographic lineages were defined based on phylogenetic tree and network analyses of COI haplotypes.AMOVA results indicated that genetic variations mainly occurred among the three lineages(89.96%).Tests of neutrality and mismatch distribution suggested that T.heterochaetus underwent recent population expansion.These results provide the first report on the genetic status of T.heterochaetus and will be valuable for the management of genetic resources and better understanding of the ecology and evolution in this species.
文摘BACKGROUND:Whether splenectomy can be performed simultaneously during liver transplantation in patients with end-stage liver diseases complicated by hypersplenism remains controversial.This study aimed to compare the impact of simultaneous splenectomy on high-and low-risk liver transplant patients with end-stage liver diseases and severe hypersplenism.METHODS:Forty-two patients with end-stage liver diseases complicated by severe hypersplenism who had undergone orthotopic liver transplantation were enrolled in this study.Splenectomy was performed in 19 of the patients.The 42 patients were grouped according to the risk of liver diseases and operations they received.Patients were considered to be at high-risk if they had at least one of the following conditions:preoperative prothrombin time>5 seconds,portal vein thrombosis,and severe perisplenitis.High-risk patients who had undergone splenectomy were classified into group A,whereas high-risk patients who had not undergone splenectomy were classified into group B.Low-risk patients who had undergone splenectomy were classified into group C,and low-risk patients who had spleen preservation were classified into group D.Operative time,intraoperative blood loss,postoperative bleeding,pulmonary infection,perioperative mortality,and postoperative platelet recovery were analyzed.RESULTS:Operative time and intraoperative blood loss were greater in group A than in groups B-D(P<0.01),but there was no significant difference between groups C and D(P>0.05).In group A,3 patients had postoperative bleeding,5 had pulmonary infection,and 2 had perioperative mortality,which was higher than any other group,but postoperative bleeding,pulmonary infection,and perioperative mortality were similar to those in groups C and D.In patients undergoing simultaneous splenectomy,platelet counts recovered within 6 months after surgery.Thrombocytopenia was sustained in 3 of the 23 patients who did not undergo simultaneous splenectomy.CONCLUSION:Splenectomy should be avoided during orthotopic liver transplantation in high-risk patients,but this procedure does not increase the operative risk in low-risk patients and may be a valuable method to ensure good postoperative platelet recovery.
基金the National Natural Science Foundation of China(Grant No.51975240)the Open Fund of State Key Laboratory of Advanced Forming Technology and Equipment(Grant No.SKL2019006).
文摘The paper aims at modeling and simulating the atomization process of the close-coupled ring-hole nozzle in vacuum induction gas atomization(VIGA)for metallic powder production.First of all,the primary atomization of the ring-hole nozzle is simulated by the volume of fluid(VOF)coupled large eddy simulation(LES)model.To simulate the secondary atomization process,we use the method of selecting the droplet sub-model and the VOF model.The results show that the ring-hole nozzle forms a gas recirculation zone at the bottom of the delivery tube,which is the main reason for the formation of an annular liquid film during the primary atomization.In addition,the primary atomization process of the ring-hole nozzle consists of three stages:the formation of the serrated liquid film tip,the appearance and shedding of the ligaments,and the fragmentation of ligaments.At the same time,the primary atomization mainly forms spherical droplets and long droplets,but only the long droplets can be reserved and proceed to the secondary atomization.Moreover,increasing the number of ring holes from 18 to 30,the mass median diameter(MMD,d_(50))of the primary atomized droplets decreases first and then increases,which is mainly due to the change of the thickness of the melt film.Moreover,the secondary atomization of the ring-hole nozzles is mainly in bag breakup mode and multimode breakup model,and bag breakup will result in the formation of hollow powder,which can be avoided by increasing the gas velocity.
基金Supported by the CNPC Huabei Oilfield Science and Technology Development Project(HBYT-CYY-2014-JS-378,HBYT-CYY-2015-JS-47)
文摘The adsorption behavior of CO_2, CH_4 and their mixtures in bituminous coal was investigated in this study. First, a bituminous coal model was built through molecular dynamic(MD) simulations, and it was confirmed to be reasonable by comparing the simulated results with the experimental data. Grand Canonical Monte Carlo(GCMC)simulations were then carried out to investigate the single and binary component adsorption of CO_2 and CH_4with the built bituminous coal model. For the single component adsorption, the isosteric heat of CO_2 adsorption is greater than that of CH_4 adsorption. CO_2 also exhibits stronger electrostatic interactions with the heteroatom groups in the bituminous coal model compared with CH_4, which can account for the larger adsorption capacity of CO_2 in the bituminous coal model. In the case of binary adsorption of CO_2 and CH_4mixtures, CO_2 exhibits the preferential adsorption compared with CH_4 under the studied conditions. The adsorption selectivity of CO_2 exhibited obvious change with increasing pressure. At lower pressure, the adsorption selectivity of CO_2 shows a rapid decrease with increasing the temperature, whereas it becomes insensitive to temperature at higher pressure. Additionally, the adsorption selectivity of CO_2 decreases gradually with the increase of the bulk CO_2 mole fraction and the depth of CO_2 injection site.
基金financially supported by the Natural Science Foundation Committee of Inner Mongolia (No.20080404MS0204)the "111 Talents Project" Foundation of Inner Mongolia,Chinathe Innovation Fund of Inner Mongolia University of Science and Technology (No.2010NC026)
文摘The CaLaGa3O7：Eu3＋ phosphor was prepared by a chemical co-precipitation method. Field emission scanning electron microscopy （FE-SEM）, laser particle size analysis, X-ray diffraction （XRD）, photoluminescence （PL）, and cathodoluminescence （CL） spectra were util- ized to characterize the synthesized phosphor. The results revealed that the phosphor was composed of microspheres with a slight agglomerate phenomenon and was spherically shaped. The average grain size was about 1.0 μm. Eu3＋ ions, as luminescent centers, substituted La3＋ ions into the single crystal lattice of CaLaGa307 with the sites of Cs. Although the CL spectrum was greatly different from the PL spectrum, it had the strongest red emission corresponding to the 5D0→7F2 transition of Eu3＋. Under the excitation of UV light （287 nm） and electron beams （1.0-7.0 kV）, the chromaticity coordinates of the phosphor were found to be in the nearly red and orange light regions, respec- tively.
基金supported by the Outstanding Youth Foundation of NSFC (31025026)the Creative Team Project of Chinese Ministry of Education (IRT-0831)+1 种基金the National Natural Science Foundation of China (30800606 and 31072010)the Natural Science Foundation of Hubei Province (2010CDB10106)
文摘BTG1 （B-cell Translocation Gene 1） , a member of the BTG / TOB （Transducer of ErbB-2） family of anti-proliferation factors,has been proven to have an unfavorable effect on muscle fiber growth in several species. The porcine BTG1 gene was cloned and its 5＇ flanking promoter region sequence, and characterized the expression patterns in different tissues of adult pigs and in fetal skeletal muscle at different developmental stages in two breeds. The tissue distribution pattern analyses revealed that the mRNA of porcine BTG1 was ubiquitously expressed in the six tissues of both Landrace and Tongcheng pigs. Real-time quantitative reverse transcriptase-PCR results showed that BTG1 mRNA expression levels were significantly different among the three fetal ages in Tongcheng pigs,while no significant differences were found among the three ages in Landrace pigs. Furthermore,the expression of BTG1 in Landrace pigs was significantly lower than in Tongcheng pigs at all three ages. The temporal expression profiles of the BTG1 gene in mouse myoblast C 2 C 12 cells were shown to be consistent with those of the myogenin gene. A single nucleotide polymorphism （SNP） ,g. 281C 〉 T,was identified in the 3＇UTR and allele frequencies were detected in seven pig breed populations. Significant associations were found between the g. 281C 〉 T polymorphism and growth and meat quality traits. Our results indicate that the porcine BTG1 gene could play a potential role in markerassisted selection and as such may be a gene of economic importance.
基金supported by the Major Science and Technology Program for Water Pollution Control and Treatment of China (No. 2011ZX07301-003)the National Key Research and Development Plan (No. 2016YFC0400806)
文摘Anaerobic treatment is the core technology for resource and energy recovery from source-separated domestic bio-wastes. The higher efficiency of an improved upflow solid reactor（IUSR） designed in this study was demonstrated in the treatment of concentrated black water and kitchen waste. The highest methane production of 48 L/person/day was achieved at the hydraulic retention time（HRT） of 7 days, while the other measures of performance at the HRT of 8.3 days were better than at the HRT of 7 or 10 days, achieving a methane production of 43 L/person/day, removal of total chemical oxygen demand（TCOD）of 89%, removal of soluble chemical oxygen demand（SCOD） of 92%, and conversion of chemical oxygen demand（COD） to methane of 71%. It is not recommended to decrease HRT lower than 7 days due to the instability of the initial period. The concentrations of volatile fatty acids（VFAs） in the IUSR were less than 10 mg/L, indicating that the anaerobic process was stable. Sludge bed development showed that sludge bed with high microbial activity was formed in the bottom and that the precipitation zone of effluents formed should preferably occupy 30% of the height of the IUSR. The effluents of the IUSR could be used for irrigation in agriculture in combination with a settling tank accompanied by disinfection to remove solids and pathogens.
基金supported in part by the National Key Research and Development Program of China(2020YFB1313002)the National Natural Science Foundation of China(62276023,U22B2055,62222302,U2013202)+1 种基金the Fundamental Research Funds for the Central Universities(FRF-TP-22-003C1)the Postgraduate Education Reform Project of Henan Province(2021SJGLX260Y)。
文摘Underwater image enhancement aims to restore a clean appearance and thus improves the quality of underwater degraded images.Current methods feed the whole image directly into the model for enhancement.However,they ignored that the R,G and B channels of underwater degraded images present varied degrees of degradation,due to the selective absorption for the light.To address this issue,we propose an unsupervised multi-expert learning model by considering the enhancement of each color channel.Specifically,an unsupervised architecture based on generative adversarial network is employed to alleviate the need for paired underwater images.Based on this,we design a generator,including a multi-expert encoder,a feature fusion module and a feature fusion-guided decoder,to generate the clear underwater image.Accordingly,a multi-expert discriminator is proposed to verify the authenticity of the R,G and B channels,respectively.In addition,content perceptual loss and edge loss are introduced into the loss function to further improve the content and details of the enhanced images.Extensive experiments on public datasets demonstrate that our method achieves more pleasing results in vision quality.Various metrics(PSNR,SSIM,UIQM and UCIQE) evaluated on our enhanced images have been improved obviously.
基金supported in part by the Institute for Advanced Study of Central South University and the High Performance Computing Center of Central South Universitythe funding from Guangdong Natural Science Funds(No.2023A0505050107)。
文摘Regulating the catalyst electronic structure is critical for improving the adsorption and catalytic conversion of lithium polysulfides(LiPSs)in lithium-sulfur batteries(Li-S),yet which has been overlooked in current studies.In this work,structurally defined Ag_(30)Pd_(4)nanoclusters were loaded onto reduced graphene oxide(Ag_(30)Pd_(4)/rGO)as a modification material for polypropylene(PP)separators to elucidate the catalytic activity towards lithium polysulfides and the impact on the electrochemical properties to lithium sulfur batteries.This unique d-πcombination promotes charge transfer,influences overall charge states,and further enhances adsorption energies in potential reaction pathways with lithium polysulfides.Consequently,the Ag_(30)Pd_(4)/rGO/PP modified batteries exhibited an exceptionally low-capacity decay rate of 0.026%per cycle at 1.0C over 1000 stable cycles and 9.75 mAh cm^(-2)excellent performance even with lean electrolyte and high sulfur loading(9.7 mg cm^(-2)).This study paves a path for employing ultrasmall bimetallic nanoclusters to promote the polysulfides redox kinetics hence boosting the lithiumsulfur battery performance.
基金This work was supported by the National Natural Science Foundation of China(Nos.20374034,50225311).
文摘Poly（p-phenylene） （PPP） films have been electrochemically deposited on mirrorlike stainless steel （SS） electrode surfaces by direct oxidation of benzene in boron trifluoride diethyl etherate （BFEE） solutions at a constant applied potential of 1.7 V （versus Ag/AgCl）. The chain conformations of as-grown PPP films have been studied by Raman spectroscopy. The results demonstrated that high synthesis temperature favors the formation of planar PPP, and the conformation of planar PPP can be changed into torsional PPP by cooling treatment.
文摘Anterior cervical decompression and fusion(ACDF)treatment for cervical spondylosis has been more than half a century,and achieved good clinical results.However,with the continuous extension of follow-up time,the fusion segment-associated postoperative complications emerged gradually.Reserved cervical stability and activity,the concept of non-fusion was born.As a non-fusion technique,cervical artificial disc replacement(CADR)developed rapidly.With the continuous development of artificial prosthesis materials and design concepts,and specification and proficiency of surgical procedures,CADR has achieved better short and mid-term clinical efficacy than ACDF.Compared with ACDF,the main advantages of CADR are that the postoperative recovery is quick,the activity and stability of cervical vertebra are maintained,the height of cervical intervertebral space is restored,and the stress of adjacent segments and the rate of surgical renovation are reduced.In clinical work,as an emerging technology,CADR requires spine surgeons to control the surgical indications,contraindications,and patients'conditions strictly.This article reviews the research progress of CADR in order to provide new ideas for clinical treatment of cervical spondylosis.
