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1An experimental study on stress-strain behavior and constitutive model of hardfill material显示文摘Hardfill is a new type of artificially cemented material for dam construction works,with a wide application prospect.Its mechanical behavior lies between concrete and rockfill materials.A series of large-scale triaxial tests are performed on hardfill specimens at different ages,and the stress-strain behavior of hardfill is further discussed.The strength and stress-strain relationship of hardfill materials show both frictional mechanism and cohesive mechanism.An age-related constitutive model of hardfill is developed,which is a parallel model consisting of two components,rockfill component and cementation component.Moreover,a comparison is made between the simulated and the experimental results,which shows that the parallel model can reflect the mechanical characteristics of both rockfill-like nonlinearity and concrete-like age relativity.In addition,a simplified method for the determination of parameters is proposed.WU MengXi DU Bin YAO YuanCheng HE XianFeng 2011Science China(Physics,Mechanics & Astronomy)2011,54,11:15
2A unifying approach in simulating the shot peening process using a 3D random representative volume finite element model显示文摘Using a modified 3D random representative volume(RV)finite element model,the effects of model dimensions(impact region and interval between impact and representative regions),model shapes(rectangular,square,and circular),and peening-induced thermal softening on resultant critical quantities(residual stress,Almen intensity,coverage,and arc height)after shot peening are systematically examined.A new quantity,i.e.,the interval between impact and representative regions,is introduced and its optimal value is first determined to eliminate any boundary effect on shot peening results.Then,model dimensions are respectively assessed for all model shapes to reflect the actual shot peening process,based on which shape-independent critical shot peening quantities are obtained.Further,it is found that thermal softening of the target material due to shot peening leads to variances of the surface residual stress and arc height,demonstrating the necessity of considering the thermal effect in a constitutive material model of shot peeing.Our study clarifies some of the finite element modeling aspects and lays the ground for accurate modeling of the SP process.Dianyin HU Ye GAO Fanchao MENG Jun SONG Yanfei WANG Mengxi REN Rongqiao WANG 2017Chinese Journal of Aeronautics2017,30,4:13
3Regulation network and expression profiles of Epstein-Barr virus-encoded microRNAs and their potential target host genes in nasopharyngeal carcinomas显示文摘Epstein-Barr virus(EBV)is associated with nasopharyngeal carcinoma(NPC)tumorigenesis.However,the mechanism(s)connecting EBV infection and NPC remain unclear.Recently,a new class of EBV microRNAs(miRNAs)has been described.To determine how EBV miRNAs control the expression of host genes,and to understand their potential role in NPC tumorigenesis,we profiled the expression of 44 mature EBV miRNAs and potential host genes in NPC and non-tumor nasopharyngeal epithelial tissues.We found that 40 EBV miRNAs from the BART transcript were highly expressed in NPC.Analysis of potential BART miRNA target genes revealed that 3140 genes and several important pathways might be involved in the carcinogenesis of NPC.A total of 105 genes with potential EBV miRNA binding sites were significantly downregulated,suggesting that EBV miRNAs may regulate these genes and contribute to NPC carcinogenesis.An EBV miRNA and host gene regulation network was generated to provide useful clues for validating of EBV miRNA functions in NPC tumorigenesis.ZENG ZhaoYang HUANG HongBin HUANG LiLi SUN MengXi YAN QiJia SONG YaLi WEI Fang BO Hao GONG ZhaoJian ZENG Yong LI Qiao ZHANG WenLing LI XiaYu XIANG Bo LI XiaoLing LI Yong XIONG Wei LI GuiYuan 2014Science China(Life Sciences)2014,57,3:10
4Zircon U/Pb dating and Hf-O isotopes of the Zhouan ultramafic intrusion in the northern margin of the Yangtze Block,SW China:Constraints on the nature of mantle source and timing of the supercontinent Rodinia breakup显示文摘The Zhouan ultramafic intrusion in the northern margin of the Yangtze Block is mainly composed of lherzolite.Zircon grains selected from lherzolite are irregular in shape with distinct oscillatory and sector zoning and have Th/U ratios ranging from 0.8 to 10.6,indicating a magmatic origin.The weighted average 206 Pb/238 U age is 637±4 Ma (2σ,n=15),which can be considered as the crystallization age of the Zhouan intrusion.Zircon grains have δ18O values ranging from 5.2‰ to 7.0‰,with an averaged value of 5.8±0.4‰ (1σ,n=33),similar to the mantle δ18O value of zircon.Their 176Hf/177Hf(t) ratios range from 0.282410 to 0.282594 with εHf(t) values ranging from 1.3 to 7.6,lower than the corresponding value of the depleted mantle (~15),indicating an enriched mantle source.The enriched mantle source may have generated from a metasomatized lithospheric mantle with subducted slab.A number of ~635 Ma mafic-ultramafic intrusions in the Suizao basin are associated with coeval bimodal volcanics of the Yaolinghe Formation,indicating a continental rift setting.The ~635 Ma magmatic event in this region may represent the product of the last breakup of the Rodinia supercontinent in the northern margin of the Yangtze Block at Neoproterozoic.WANG MengXi WANG ChristinaYan ZHAO JunHong 2013Science China(Technological Sciences)2013,56,3:10
5Long-term bone and lung consequences associated with hospital-acquired severe acute respiratory syndrome:a 15-year follow-up from a prospective cohort study显示文摘The most severe sequelae after rehabilitation from SARS are femoral head necrosis and pulmonary fibrosis. We performed a 15-year follow-up on the lung and bone conditions of SARS patients. We evaluated the recovery from lung damage and femoral head necrosis in an observational cohort study of SARS patients using pulmonary CT scans, hip joint MRI examinations, pulmonary function tests and hip joint function questionnaires. Eighty medical staff contracted SARS in 2003. Two patients died of SARS, and78 were enrolled in this study from August 2003 to March 2018. Seventy-one patients completed the 15-year follow-up. The percentage of pulmonary lesions on CT scans diminished from 2003(9.40 ± 7.83)% to 2004(3.20 ± 4.78)%(P < 0.001) and remained stable thereafter until 2018(4.60 ± 6.37)%. Between 2006 and 2018, the proportion of patients with interstitial changes who had improved pulmonary function was lower than that of patients without lesions, as demonstrated by the one-second ratio(FEV1/FVC%, t = 2.21, P = 0.04) and mid-flow of maximum expiration(FEF25%–75%, t = 2.76, P = 0.01). The volume of femoral head necrosis decreased significantly from 2003(38.83 ± 21.01)% to 2005(30.38 ± 20.23)%(P = 0.000 2), then declined slowly from 2005 to 2013(28.99 ± 20.59)% and plateaued until 2018(25.52 ± 15.51)%. Pulmonary interstitial damage and functional decline caused by SARS mostly recovered, with a greater extent of recovery within 2 years after rehabilitation. Femoral head necrosis induced by large doses of steroid pulse therapy in SARS patients was not progressive and was partially reversible.Peixun Zhang Jia Li Huixin Liu Na Han Jiabao Ju Yuhui Kou Lei Chen Mengxi Jiang Feng Pan Yali Zheng Zhancheng Gao Baoguo Jiang 2020Bone Research2020,8,1:8
6A novel lncRNA, Lnc-OC1, promotes ovarian cancer cell proliferation and migration by sponging miR-34a and miR-34c显示文摘Long non-coding RNAs(lncRNAs) have been reported to be of great importance in tumorigenesis and progression of a variety of cancers. However, the role of lncRNAs in ovarian cancer(OC) remains largely unknown. In the present study, we identified a novel lncRNA, LOC100288181(named as Lnc-OC1), which acted as a key regulator in the development and progression of OC. The combined Gene Expression Omnibus(GEO) database analysis revealed that Lnc-OC1 was significantly upregulated in OC tissues and Kaplan-Meier survival analysis confirmed that high Lnc-OC1 expression was associated with poor prognosis of OC patients. Importantly, we also demonstrated that knockdown of Lnc-OC1 suppressed cell proliferation, colony formation, invasion and migration in vitro and inhibited tumorigenicity in vivo.Mechanistically, Lnc-OC1 repressed the expression of endogenous miR-34 a and miR-34 c as a sponge and vice versa. Moreover, rescue experiments demonstrated that the oncogenic function of Lnc-OC1 at least partially depended on suppressing miR-34 a and miR-34 c. In conclusion, our results suggest that the LncOC1-miR-34 a/34 c axis may play a pivotal role in OC, and may serve as a potential diagnostic biomarker and a powerful therapeutic target for OC.Fangfang Tao Xinxin Tian Mengxi Lu Zhiqian Zhang 2018Journal of Genetics and Genomics2018,45,3:8
7Protective effect of Yiguanjian decoction against DNA damage on concanavalin A-induced liver injury mice model显示文摘OBJECTIVE:To investigate the inhibitory effect of Yiguanjian decoction(YD) on DNA damage in Concanavalin A(Con A)-induced liver injury mice model and to explain the possible mechanism.METHODS:Totally 120 male BALB/c mice were randomly divided into 6 groups,20 mice each:normal group,model group,Bifendate group,YD low dose group,YD middle dose group and YD high dose group.Except normal group,liver injury model induced by Con A was established.While modeling,each mouse in YD group was given YD(0.4 m L/20 g per day) by intragastric administration(0.13 g YD for YD low dose group;0.26 g for YD middle dose group;0.52 g for YD high dose group).Bifendate group was given Bifendate(0.2 gnd model·kg-1 grou·d-1) by gavage.Normal group ap were fed with same volume of physiological saline daily.After 8 weeks,the serum alanine transaminase(ALT)and aspartate transaminase(AST) were tested.The hematoxylin-eosin staining was used to evaluate the grade of liver inflammation and liver fibrosis stage.Hepatocellular DNA damage was detected by single cell gel electrophoresis technology.The protein expression of tumor necrosis factor-α(TNF-α),Bax and Mut T Homolog 1(MTH1) was detected by western blotting and enzyme linked immunosorbent assay.Bax m RNA and MTH1 m RNA were detected by Real-time Polymerase Chain Reaction(PCR).RESULTS:YD can improve the degree of liver inflammation and fibrosis in the liver of chronic hepatitis mice,the dose effect relationship is remarkable(P < 0.05).YD can reduce liver cell DNA damage.The difference between YD middle dose group and model group was statistically significant(P < 0.05).YD middle dose group had decreased the protein expression of TNF-α in the mice liver of immunological liver injury(P < 0.05).YD can increase the protein expression of Bax(P < 0.05).Compared with normal group,the protein expression of MTH1 was decreased(P < 0.05),but there was no statistical significance between YD group and model group(P >0.05).YD can increase the m RNA expression of Bax and MTH1(both P < 0.05).CONCLUSION:YD can effectively inhibit the DNA damage in immunological liver injury mice,the mechanism may be that it can decrease the TNF-αand increase the Bax and MTH1 expression.Tian Mengxi Liu Wenlan You Hongjie Zhao Qingzhou Ouyang Luodan Gao Biane Zhang Xin Che Niancong 2016Journal of Traditional Chinese Medicine2016,36,4:7
8Simulation procedure of unconfined seepage with an inner seepage face in a heterogeneous field显示文摘An inner seepage face phenomenon is given and a numerical simulation procedure has been developed.It may appear at the interface of two materials when an unconfined seepage flows from a porous media to a coarser porous media with a higher permeability.Inaccuracy and divergent problems may arise both in a saturated-only and in a variably saturated analysis while an inner seepage face is not simulated with a special procedure.The position of the seepage face is determined during the nonlinear iteration process and the flux of the inner seepage face nodes is transferred to the downstream side nodes.Validity and efficiency of the procedure are illustrated by the simulation of two dimensional steady state seepage examples of heterogeneous zoned dams which is usually used to validate algorithms.An analysis of a three-dimensional earth core rockfill dam is also presented here.The procedure can also be applied to general transient seepage problems.WU MengXi YANG LianZhi YU Ting 2013Science China(Physics,Mechanics & Astronomy)2013,56,6:7
9Low-temperature NH_(3)-SCR of NO_(x) over MnCeO_(x)/TiO_(2) catalyst:Enhanced activity and SO_(2) tolerance by modifying TiO_(2) with Al_(2)O_(3)显示文摘A series of TiO_(2)-Al_(2)O_(3) composites with Al/Ti molar ratios of 0.1,0.2,and 0.4 were synthesized by a coprecipitation method and used as supports to prepare supported MnCeO_(x) catalysts by an impregnation method.The physico-chemical properties of the samples were extensively characterized by N_(2) physisorption,X-ray diffraction,Raman spectroscopy,scanning electron micro scopy and energy-dispersive Xray spectroscopy element mapping,X-ray photoelectron spectroscopy,H_(2)-temperature programmed reduction,ammonia temperature programmed desorption,and in-situ diffuse reflectance infrared Fourier transform spectroscopy.The catalytic activity and resistance to water vapor and SO_(2) of the asprepared catalysts for the SCR of NO_(x) with NH_(3) were evaluated at 50-250℃ and GHSV of 80000 mL/(gcat·h).The results reveal that MnCeO_(x)/TiO_(2)-Al_(2)O_(3) exhibits higher activity and better SO_(2) tolerance than MnCeO_(x)/TiO_(2).Combining with the characterization results,the enhanced activity and SO_(2) tolerance of MnCeO_(x)/TiO_(2)-Al_(2)O_(3) can be mainly attributed to higher relative concentrations of Mn4+and chemisorbed oxygen species,stronger reducibility,and larger adsorption capacity for NH_(3) and NO,which originate from the larger specific surface area and pore volume,higher dispersion of Mn and Ce species compared with MnCeO_(x)/TiO_(2).Moreover,in situ DRIFTS was used to investigate the reaction mechanism,and the results indicate that the NH_(3)-SCR reaction over MnCeO_(x)/TiO_(2) and MnCeO_(x)/TiO_(2)-Al_(2)O_(3) takes place by both the E-R and L-H mechanisms.Gang Li Dongsen Mao Mengxi Chao Gehua Li Jun Yu Xiaoming Guo 2021Journal of Rare Earths2021,39,7:6
10Model simulations of the annual cycle of the landfast ice thickness in the East Siberian Sea显示文摘The annual cycle of the thickness and temperature of landfast sea ice in the East Siberian Sea has been examined using a one-dimensional thermodynamic model. The model was calibrated for the year August 2012–July 2013, forced using the data of the Russian weather station Kotel'ny Island and ECMWF reanalyses. Thermal growth and decay of ice were reproduced well, and the maximum annual ice thickness and breakup day became 1.64 m and the end of July. Oceanic heat flux was 2 W.m–2 in winter and raised to 25 W.m–2 in summer, albedo was 0.3–0.8 depending on the surface type(snow/ice and wet/dry). The model outcome showed sensitivity to the albedo, air temperature and oceanic heat flux. The modelled snow cover was less than 10 cm having a small influence on the ice thickness. In situ sea ice thickness in the East Siberian Sea is rarely available in publications. This study provides a method for quantitative ice thickness estimation by modelling. The result can be used as a proxy to understand the sea ice conditions on the Eurasian Arctic coast, which is important for shipping and high-resolution Arctic climate modelling.YANG Yu Matti Leppranta LI Zhijun Bin Cheng ZHAI Mengxi Denis Demchev 2015Advances in Polar Science2015,26,2:5
11Rice productivity and profitability with slow-release urea containing organic-inorganic matrix materials显示文摘Applying slow-release fertilizers is possible means for reducing nitrogen(N) loss in rice production. Matrix-based fertilizers represent novel slow-release fertilizers. To date, there is little consensus about the effect of combined addition of organic and inorganic matrix materials on rice production. We developed a slow-release urea fertilizer with selected organic and inorganic matrix materials. The study aimed to: i) determine the effect of the slow-release urea on rice yield, profit, and agronomic efficiency and ii) elucidate its possible mechanisms. A two-year field experiment was conducted during 2015–2016. Besides,laboratory experiments were conducted to determine the potential N loss risk. Three treatments were set up: control without N application(CK), regular urea treatment(RU, 150 kg N ha^(-1)), and slow-release urea treatment(SU, 150 kg N ha^(-1)). The results showed that rice biomass and grain yield were significantly higher in SU than in RU(P < 0.05). The higher panicle density in SU was largely responsible for the greater grain yield. Net profit in SU was US$450 ha^(-1), higher than in RU. Agronomic efficiency was significantly greater in SU than in RU(P < 0.05). Rice height, root area, leaf chlorophyll, leaf nitrate reductase activity, and leaf glutamine synthetase activity were larger in SU than in RU. Less N loss and greater soil N availability were partly responsible for the improvements in rice growth traits and physiological parameters in SU. Overall, the slow-release urea is a promising fertilizer for rice production.Yang YANG Binmei LIU Xiaoyu NI Liangzhi TAO Lixiang YU Ye YANG Mengxi FENG Wenjin ZHONG Yuejin WU 2021Pedosphere2021,31,4:5
12Hydrodynamics and Mass Transfer in a Modified Three-phase Airlift Loop Reactor显示文摘A modified internal-loop airlift reactor (MIALR) with a continuous slurry phase was studied to investigate the local hydrodynamic characteristics, including gas holdup, bubble size, bubble rise velocity and local mass transfer properties. Based on the analysis of geometrical construction and fluid properties of gas and slurry, MIALR was divided into six flow regions. In these flow regions, the local hydrodynamic characteristics were investigated over a wide range of operating variables. Furthermore, a new method was developed to measure the dissolved oxygen concentration. The volumetric mass-transfer coefficient in six flow regions was also calculated for comparison.Liu Mengxi Lu Chunxi Shi Mingxian Ge Baoli Huang Jie 2007Petroleum Science2007,4,3:5
13Distinct immune signatures discriminate between asymptomatic and presymptomatic SARS-CoV-2^(pos)subjects显示文摘Increasing numbers of SARS-CoV-2-positive(SARS-CoV-2^(pos))subjects are detected at silent SARS-CoV-2 infection stage(SSIS).Yet,SSIS represents a poorly examined time-window wherein unknown immunity patterns may contribute to the fate determination towards persistently asymptomatic or overt disease.Here,we retrieved blood samples from 19 asymptomatic and 12 presymptomatic SARS-COV-2^(pos)subjects,47 age/gender-matched patients with mild or moderate COVID-19 and 27 normal subjects,and interrogated them with combined assays of 44-plex CyTOF,RNA-seq and Olink.Notably,both asymptomatic and presymptomatic subjects exhibited numerous readily detectable immunological alterations,while certain parameters including more severely decreased frequencies of CD107a^(low)classical monocytes,intermediate monocytes,non-classical monocytes and CD62L^(hi)CD8^(+)Tnaive cells,reduced plasma STC1 level but an increased frequency of CD4^(+)NKT cells combined to distinguish the latter.Intercorrelation analyses revealed a particular presymptomatic immunotype mainly manifesting as monocytic overactivation and differentiation blockage,a likely lymphocyte exhaustion and immunosuppression,yielding mechanistic insights into SSIS fate determination,which could potentially improve 5ARS-CoV-2 management.Shanhe Yu Caixia Di Shijun Chen Mingquan Guo Jiayang Yan Zhaoqin Zhu Li Liu Ruixue Feng Yinyin Xie Ruihong Zhang Juan Chen Mengxi Wang Dong Wei Hai Fang Tong Yin Jinyan Huang Saijuan Chen Hongzhou Lu Jiang Zhu Jieming Qu 2021Cell Research2021,31,11:4
14Monitoring the Amery Ice Shelf front during 2004-2012 using ENVISAT ASAR data显示文摘The Amery Ice Shelf is the largest ice shelf in East Antarctica. It drains continental ice from an area of more than one million square kilometres through a section of coastline that represents approximately 2% of the total circumference of the Antarctic continent. In this study, we used a time series of ENVISAT ASAR images from 2004-2012 and flow lines derived from surface velocity data to monitor the changes in 12 tributaries of the Amery Ice Shelf front. The results show that the Amery Ice Shelf has been expanding and that the rates of expansion differ across the shelf. The highest average annual rate of advance from 2004-2012 was 3.36 m·d-1 and the lowest rate was 1.65 m·d-1 . The rates in 2009 and 2010 were generally lower than those in other years. There was a low correlation between the rate of expansion and the atmospheric temperature recorded at a nearby research station, however the mechanism of the relationship was complex. This study shows that the expansion of the Amery Ice Shelf is slowing down, reflecting a changing trend in climate and ice conditions in East Antarctica.ZHAO Chen CHENG Xiao HUI Fengming KANG Jing LIU Yan WANG Xianwei WANG Fang CHENG Cheng FENG Zhunzhun CI Tianyu ZHAO Tiancheng ZHAI Mengxi 2013Advances in Polar Science2013,24,2:4
15Clean transfer of graphene on Pt foils mediated by a carbon monoxide intercalation process显示文摘象磅那样的高贵金属是为单层 graphene 的催化生长的完美的底层。然而,随后的转移过程的要求不与传统的蚀刻方法兼容。在这个工作,我们发现有磅陪衬的 graphene 的相互作用能在周围的压力下面通过碳一氧化物(公司) 的置闰被削弱。这个置闰过程在从 0 ~ 0.6 MPa 改变 CO 部分压力上发生在两个六角形形状的 graphene 岛和不规则的 graphene 补丁上,作为由扫描电子显微镜学(SEM ) 观察了,拉曼光谱学和 X 光检查光致核裂变光谱学。我们证明在实际 timescale 上,置闰比率而且与公司的部分压力成正比,我们作为一个脱皮的代理人与水开发共同设置的 graphene 的一个干净转移方法。我们证明这个方法启用十个测微计规模 graphene 补丁的转移到 SiO2/Si 上,它从金属或氧化物粒子污染是免费的。这个转移方法应该是向 graphene,以及高贵金属底层的 recyclable 使用的干净转移的重要的步。Donglin Ma Yanfeng Zhang Mengxi Liu Qingqing Ji Teng Gao Yu Zhang Zhongfan Liu 2013Nano Research2013,6,9:3
16Optimal reaction conditions for pyridine synthesis in riser reactor显示文摘Pyridine has been generally synthesized by aldehydes and ammonia in a turbulent fluidized-bed reactor. In this paper, a novel riser reactor was proposed for pyridine synthesis. Experiment result showed that the yield of pyridine and 3-picoline decreased, but the selectivity of pyridine over 3-picoline increased compared to turbulent fluidized-bed reactor. Based on experimental data, a modified kinetic model was used for the determination of optimal operating condition for riser reactor. The optimal operating condition of riser reactor given by this modified model was as follows: The reaction temperature of 755 K, catalyst to feedstock ratio(CTFR) of 87, residence time of 3.8 s and initial acetaldehydes concentration of 0.0029 mol·L^(-1)(acetaldehydes to formaldehydes ratio by mole(ATFR) of 0.65 and ammonia to aldehydes ratio by mole(ATAR) of 0.9, water contention of 63 wt%(formaldehyde solution)).Shuaishuai Zhou Zelong Liu Xiao Yan Qin Di Mengxi Liu Chunxi Lu Guangzhou Jin 2018Chinese Journal of Chemical Engineering2018,26,7:3
17Characterization of the unprecedented polynya events north of Greenland in 2017/2018 using remote sensing and reanalysis data显示文摘Based on an ice concentration threshold of 90%,it has been identified that two polynya events occurred in the region north of Greenland during the 2017/2018 ice season.The winter event lasted from February 20 to March 3,2018 and the summer event persisted from August 2 to September 5,2018.The minimum ice concentration derived from Advanced Microwave Scanning Radiometer 2(AMSR2)observations was 72%and 65%during the winter and summer events,respectively.The occurrence of both events can be related to strengthened southerly winds associated with an increased east-west zonal surface level air pressure gradient across the north Greenland due to perturbation of mid-troposphere polar vortex.The relatively warm air temperature during the 2017/2018 freezing season in comparison with previous years,together with the occurrence of the winter polynya,formed favourable pre-conditions for ice field fracturing in summer,which promoted the formation of the summer polynya.Diminished southerly winds and increased cover of new ice over the open water were the dominant factors for the disappearance of the winter polynya,whereas increased ice inflow from the north was the primary factor behind the closure of the summer polynya.Sentinel-1 Synthetic Aperture Radar(SAR)images were found better suited than AMSR2 observations for quantification of a new ice product during the polynya event because the SAR images have high potential for mapping of different sea ice regimes with finely spatial resolution.The unprecedented polynya events north of Greenland in 2017/2018 are important from the perspective of Arctic sea ice loss because they occurred in a region that could potentially be the last“Arctic sea ice refuge”in future summers.Ruibo Lei Dawei Gui Zhouli Yuan Xiaoping Pang Ding Tao Mengxi Zhai 2020Acta Oceanologica Sinica2020,39,9:3
18One-step ball milling-prepared nano Fe2O3 and nitrogendoped graphene with high oxygen reduction activity and its application in microbial fuel cells显示文摘Developing high activity,low-cost and long durability catalysts for oxygen reduction reaction is of great significance for the practical application of microbial fuel cells.The ftill exposure of active sites in catalysts can enhance catalytic activity dramatically.Here,novel Fe-N-doped graphene is successftilly synthesized via a one-step in situ ball milling method.Pristine graphite,ball milling graphene,N-doped graphene and Fe-N-doped graphene are applied in air cathodes,and enhanced performance is observed in microbial fuel cells with graphene-based catalysts.Particularly,Fe-Ndoped graphene achieves the highest oxygen reduction reaction activity,with a maximum power density of 1380±20 mW/m^2 in microbial fUel cells and a current density of 23.8 A/m^2 at-0.16 V in electrochemical tests,which are comparable to commercial Pt and 390%and 640%of those of pristine graphite.An investigation of the material characteristics reveals that the superior performance of Fe-Ndoped graphene results from the full exposure of Fe2O3 nanoparticles,pyrrolic N,pyridinic N and excellent Fe-N-G active sites on the graphene matrix.This work not only suggests the strategy of maximally exposing active sites to optimize the potential of catalysts but also provides promising catalysts for the use of microbial fuel cells in sustainable energy generation.Xingguo Guo Qiuying Wang Ting Xu Kajia Wei Mengxi Yin Peng Liang Xia Huang Xiaoyuan Zhang 2020Frontiers of Environmental Science & Engineering2020,14,2:3
19Acoustofluidic separation enables early diagnosis of traumatic brain injury based on circulating exosomes显示文摘Traumatic brain injury(TBI)is a global cause of morbidity and mortality.Initial management and risk stratification of patients with TBI is made difficult by the relative insensitivity of screening radiographic studies as well as by the absence of a widely available,noninvasive diagnostic biomarker.In particular,a blood-based biomarker assay could provide a quick and minimally invasive process to stratify risk and guide early management strategies in patients with mild TBI(mTBI).Analysis of circulating exosomes allows the potential for rapid and specific identification of tissue injury.By applying acoustofluidic exosome separation—which uses a combination of microfluidics and acoustics to separate bioparticles based on differences in size and acoustic properties—we successfully isolated exosomes from plasma samples obtained from mice after TBI.Acoustofluidic isolation eliminated interference from other blood components,making it possible to detect exosomal biomarkers for TBI via flow cytometry.Flow cytometry analysis indicated that exosomal biomarkers for TBI increase in the first 24 h following head trauma,indicating the potential of using circulating exosomes for the rapid diagnosis of TBI.Elevated levels of TBI biomarkers were only detected in the samples separated via acoustofluidics;no changes were observed in the analysis of the raw plasma sample.This finding demonstrated the necessity of sample purification prior to exosomal biomarker analysis.Since acoustofluidic exosome separation can easily be integrated with downstream analysis methods,it shows great potential for improving early diagnosis and treatment decisions associated with TBI.Zeyu Wang Haichen Wang Ryan Becker Joseph Rufo Shujie Yang Brian E.Mace Mengxi Wu Jun Zou Daniel T.Laskowitz Tony Jun Huang 2021Microsystems & Nanoengineering2021,7,2:3
20Acoustofluidic separation of cells andparticles显示文摘Acoustofluidics,the integration of acoustics and microfluidics,is a rapidly growing research field that is addressing challenges in biology,medicine,chemistry,engineering,and physics.In particular,acoustofluidic separation of biological targets from complex fluids has proven to be a powerful tool due to the label-free,biocompatible,and contact-free nature of the technology.By carefully designing and tuning the applied acoustic field,cells and other bioparticles can be isolated with high yield,purity,and biocompatibility.Recent advances in acoustofluidics,such as the development of automated,point-of-care devices for isolating sub-micron bioparticles,address many of the limitations of conventional separation tools.More importantly,advances in the research lab are quickly being adopted to solve clinical problems.In this review article,we discuss working principles of acoustofluidic separation,compare different approaches of acoustofluidic separation,and provide a synopsis of how it is being applied in both traditional applications,such as blood component separation,cell washing,and fluorescence activated cell sorting,as well as emerging applications,including circulating tumor cell and exosome isolation.Mengxi Wu Adem Ozcelik Joseph Rufo Zeyu Wang Rui Fang Tony Jun Huang 2019Microsystems & Nanoengineering2019,5,1:2
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