Upregulation of vascular endothelial growth factor A/basic fibroblast growth factor(VEGFA/b FGF)expression in the penumbra of cerebral ischemia can increase vascular volume,reduce lesion volume,and enhance neural cell...Upregulation of vascular endothelial growth factor A/basic fibroblast growth factor(VEGFA/b FGF)expression in the penumbra of cerebral ischemia can increase vascular volume,reduce lesion volume,and enhance neural cell proliferation and differentiation,thereby exerting neuroprotective effects.However,the beneficial effects of endogenous VEGFA/b FGF are limited as their expression is only transiently increased.In this study,we generated multilayered nanofiber membranes loaded with VEGFA/b FGF using layer-by-layer self-assembly and electrospinning techniques.We found that a membrane containing 10 layers had an ideal ultrastructure and could efficiently and stably release growth factors for more than 1 month.This 10-layered nanofiber membrane promoted brain microvascular endothelial cell tube formation and proliferation,inhibited neuronal apoptosis,upregulated the expression of tight junction proteins,and improved the viability of various cellular components of neurovascular units under conditions of oxygen/glucose deprivation.Furthermore,this nanofiber membrane decreased the expression of Janus kinase-2/signal transducer and activator of transcription-3(JAK2/STAT3),Bax/Bcl-2,and cleaved caspase-3.Therefore,this nanofiber membrane exhibits a neuroprotective effect on oxygen/glucose-deprived neurovascular units by inhibiting the JAK2/STAT3 pathway.展开更多
As a promising counterpart of two-dimensional metamaterials,metasurfaces enable to arbitrarily control the wavefront of light at subwavelength scale and hold promise for planar holography and applicable multiplexing d...As a promising counterpart of two-dimensional metamaterials,metasurfaces enable to arbitrarily control the wavefront of light at subwavelength scale and hold promise for planar holography and applicable multiplexing devices.Nevertheless,the degrees of freedom(DoF)to orthogonally multiplex data have been almost exhausted.Compared with state-of-theart methods that extensively employ the orthogonal basis such as wavelength,polarization or orbital angular momentum,we propose an unprecedented method of peristrophic multiplexing by combining the spatial frequency orthogonality with the subwavelength detour phase principle.The orthogonal relationship between the spatial frequency of incident light and the locally shifted building blocks of metasurfaces can be regarded as an additional DoF.We experimentally demonstrate the viability of the multiplexed holograms.Moreover,this newly-explored orthogonality is compatible with conventional DoFs.Our findings will contribute to the development of multiplexing metasurfaces and provide a novel solution to nanophotonics,such as large-capacity chip-scale devices and highly integrated communication.展开更多
Aiming at the problem of long time-consuming and low accuracy of existing age estimation approaches,a new age estimation method using Gabor feature fusion,and an improved atomic search algorithm for feature selection ...Aiming at the problem of long time-consuming and low accuracy of existing age estimation approaches,a new age estimation method using Gabor feature fusion,and an improved atomic search algorithm for feature selection is proposed.Firstly,texture features of five scales and eight directions in the face region are extracted by Gabor wavelet transform.The statistical histogram is introduced to encode and fuse the directional index with the largest feature value on Gabor scales.Secondly,a new hybrid feature selection algorithm chaotic improved atom search optimisation with simulated annealing(CIASO-SA)is presented,which is based on an improved atomic search algorithm and the simulated annealing algorithm.Besides,the CIASO-SA algorithm introduces a chaos mechanism during atomic initialisation,significantly improving the convergence speed and accuracy of the algorithm.Finally,a support vector machine(SVM)is used to get classification results of the age group.To verify the performance of the proposed algorithm,face images with three resolutions in the Adience dataset are tested.Using the Gabor real part fusion feature at 48�48 resolution,the average accuracy and 1-off accuracy of age classification exhibit a maximum of 60.4%and 85.9%,respectively.Obtained results prove the superiority of the proposed algorithm over the state-of-the-art methods,which is of great referential value for application to the mobile terminals.展开更多
Many carbonate-hosted talc mineralization,which are widespread in South China,exclusively developed in Carboniferous dolomitic limestone with many siliceous bands and nodules,and cherts.One of those typical deposits i...Many carbonate-hosted talc mineralization,which are widespread in South China,exclusively developed in Carboniferous dolomitic limestone with many siliceous bands and nodules,and cherts.One of those typical deposits is the Guling talc deposit in Mashan County,central Guangxi province,with a talc reserve of1.51 million tons.Mineral associations in the deposit are sample,mainly including talc and calcite.In this paper,Sm-Nd isotopic system and rare earth elements and yttrium(REE + Y) for the hydrothermal calcite intergrown with talc are used to constrain the age and origin of the talc mineralization.The hydrothermal calcite samples from the deposit display Sm and Nd concentrations ranging from 0.18 to 0.85 and 0.85 to 4.56 ppm,respectively,and variable Sm/Nd ratios of 0.21-0.24.These calcites further yield an Sm-Nd isochron age of 232 ±19 Ma(2a)(MSWD = 0.47) with an concordant initial ^(143)Nd-^(144)Nd ratios of 0.511967 ± 0.000017,which should be interpreted as the mineralization age of the Guling talc deposit.In addition,the calcite samples are enriched in REE with the variable SREE contents ranging from 4.82 to21.50 ppm and display relatively consistent chondritenormalized REE + Y patterns with the LREE enrichment(LREE/HREE=2.00-3.60)and the obvious negative Eu(δEu=0.52-0.68)and Ce(δCe=0.16-0.33)anomalies.The Y/Ho ratios of seven calcites varies from 43.30 to59.34,with a mean value of 49.73.The available mineral associations and REE parameters(i.e.,REE patterns and Y/Ho ratios) of those calcites indicate that the ore-forming fluids of the talc mineralization be probably derived from the meteoric waters,in particular evolved ones in the Karst areas and the ore-forming materials(e.g.,Si and Mg) are likely to be originated from the ore-bearing dolostone in the Yanguan Formation(C_1y) and underlying siliceous rocks in the Liujiang Formation(D_3l).Furthermore,the talc mineralization could take place within a hydrothermal system with relative oxidizing environment and middle temperature,due to the obvious negative Eu and Ce anomalies in the calcites in the Guling deposit.展开更多
The Shangling vanadium deposit, which occurs in the Lower Devonian Tangding formation black rock series strata, has V2O5 reserves of more than 1.5 million tons and prospective reserves of more than 2 million tons. Pre...The Shangling vanadium deposit, which occurs in the Lower Devonian Tangding formation black rock series strata, has V2O5 reserves of more than 1.5 million tons and prospective reserves of more than 2 million tons. Preliminary studies on the occurrence state of vanadium(V) in this deposit have been conducted by artificial heavy minerals concentrates, leaching experiments, scanning and transmission electron microscopy and X-ray powder diffraction.These experiments have revealed no independent vanadium mineral occurrences in the Shangling vanadium deposit and the percentages of water-soluble vanadium, hydrochloric acid soluble vanadium and HF soluble vanadium were1.93 %, 21.42 % and 76.47 %, respectively. Based on our data and earlier research, we estimate that the valences state of V absorbed onto the surface of organic matter or clastic particles are +5 and +4, accounting for 10.00 % and13.35 % of the total amount of V, respectively and the valences state of V that exist in the octahedral crystal lattice of authigenic illite include +3 and +4, accounting for71.64 % and 4.83 % of the total amount of V, respectively.By calculating the correlation between the total organic carbon and V, we infer that after deposition and before entering the crystal lattice of illite, V occurs in the form of humate complex or is adsorbed by organic matter. About4.24 % of the Al is in the octahedral crystal lattice of illite,which was replaced by the vanadium under the metallogenic environments of Shanglin.展开更多
The Habo alkaline intrusion, which is located in the south of the Sanjiang area, Yunnan Province, China, is a typical Cenozoic alkaline intrusion. There are a series of small to medium-sized Au and Pb–(Zn) deposits a...The Habo alkaline intrusion, which is located in the south of the Sanjiang area, Yunnan Province, China, is a typical Cenozoic alkaline intrusion. There are a series of small to medium-sized Au and Pb–(Zn) deposits around this intrusion. Those deposits are spatially associated with the Habo alkaline intrusion.(1) The d^(34) S values of sulfides from Au deposits range from-1.91 % to 2.69 %, which are similar to those of Pb–(Zn) deposits(-3.82 % to-0.05 %) and both indicate a much greater contribution from magma.(2) The Habo alkaline intrusion has relatively homogeneous Pb isotopic compositions with^(206)Pb/^(204) Pb ranging from 18.608 to 18.761,^(207)Pb/^(204) Pb from 15.572 to15.722 and^(208)Pb/^(204) Pb from 38.599 to 39.110. These Pb isotope ratios are similar to those of Au deposits, whose^(206)Pb/^(204) Pb range from 18.564 to 18.734,^(207)Pb/^(204) Pb from15.582 to 15.738 and^(208)Pb/^(204) Pb from 38.592 to 39.319.Pb ratios in both the intrusion and Au deposits suggest that Pb mainly derived from the depth, probably represents a mixture of mantle and crust. Pb–(Zn) deposits, however,show a decentralized trait, and most of them are similar to that of the alkaline intrusion with^(206)Pb/^(204) Pb ranging from18.523 to 18.648,^(207)Pb/^(204) Pb from 15.599 to 15.802, and^(208)Pb/^(204) Pb from 38.659 to 39.206.(3) In the plumbotectonic diagram^(207)Pb/^(204) Pb versus^(206)Pb/^(204) Pb, almost all of Au and Pb–(Zn) deposits have the same projection area with the Habo alkaline intrusion, which indicates that thosedeposits almost share the same source with the alkaline intrusion.(4) Isotopic age of the Habo alkaline intrusion is36–33 Ma, which is similar to that of Beiya, whose orerelated alkaline porphyries age is 38–31 Ma and molybdenite Re–Os age is 36.9 Ma. Therefore, along with S–Pb isotope traits, we suggest that the Habo Au and Pb–(Zn)deposits should be typically Ailaoshan-Red River Cenozoicalkaline-related deposits and ore-forming ages of these deposits should be later than that of the Habo alkaline intrusion.展开更多
Passivating undercoordinated ions is an effective way to reduce the defect densities at the surface and grain boundaries(GBs)of perovskite materials for enhanced photovoltaic performance and stability of perovskite so...Passivating undercoordinated ions is an effective way to reduce the defect densities at the surface and grain boundaries(GBs)of perovskite materials for enhanced photovoltaic performance and stability of perovskite solar cells(PSCs).Here,(BBF)complex is chosen as a multifunctional additive,which contains both C7H9N and BF3 groups working as Lewis base and Lewis acid,respectively,can bond with Pb^(2+)/I^(−) and FA+on the surface and in the GBs in the perovskite film,affording passivation of both cation and anion defects.The synergistic effect of the C7H9N and BF3 complex slows the crystallization during the perovskite film deposition to improve the crystalline quality,which reduces the trap density and the recombination in the perovskite film to suppress nonradiative recombination loss and minimizes moisture permeation to improve the stability of the perovskite material.Meanwhile,such an additive improves the energy-level alignment between the valence band of the perovskite and the highest occupied molecular orbital of the hole-transporting material,Spiro-OMeTAD.Consequently,our work achieves power conversion efficiency of 23.24%,accompanied by enhanced stability under ambient conditions and light illumination and opens a new avenue for improving the performance of PSCs through the use of a multifunctional complex.展开更多
Through analysis on water quality,planktonic organism,fish resources,and fish species diversity in Yantan water area,this paper evaluated current situation of quality of fishery ecological environment in Yantan water ...Through analysis on water quality,planktonic organism,fish resources,and fish species diversity in Yantan water area,this paper evaluated current situation of quality of fishery ecological environment in Yantan water area. The survey recorded all 52365 fishes and 1410. 2kg catches obtained by fishermen in half a year,and more than 98% catches are small fishes. The Shannon-Weiner diversity index of Yantan water area is 0. 162,Wilhm improvement index is 1. 814,DG- Findex is 0. 083,and the index of fish species diversity is far lower than other water areas. The average quantity per unit of phytoplankton is 1. 0134 million ind. / L,and the average quantity per unit of organisms is 1. 1151 mg / L. The average quantity per unit of zooplankton is 459. 6 ind. / L,and the average quantity per unit of organisms is 0. 6422 mg / L. Evaluation results indicate that water quality and planktonic organism in Yantan water area are basically normal,but fish resources are increasingly exhausted,fish resource composition is not reasonable,and fish species diversity is extremely low. From the perspective of biomanipulation,it is required to restore fishery ecological environment of reservoir area through restoring normal composition of aquatic organisms.展开更多
Although intestinal fungi play important roles in host health and disease,the composition and diversity of fungal communities remain poorly reported in fish.In this study,fungi in the fore-,mid-,and hindintestine of t...Although intestinal fungi play important roles in host health and disease,the composition and diversity of fungal communities remain poorly reported in fish.In this study,fungi in the fore-,mid-,and hindintestine of tilapia(Oreochromis mossambicus)and bighead carp(Aristichthys nobilis)from Hongchaojiang Reservoir in Guangxi,China were investigated by ITS sequencing.Based on this,we obtained 1763478 high-quality tags,which clustered into 1089 operational taxonomic units(OTUs).In total,404 OTUs were annotated,of which 310,68,and 26 belonged to Ascomycota,Basidiomycota,and other,respectively.Results show significant differences in the community composition of intestinal fungi between tilapia and bighead carp but not within their different intestinal segments.Furthermore,154 of the 404 annotated OTUs were considered reliable and were classified into three trophic modes and nine guilds.The three trophic modes consisted of 108 OTUs of saprotrophic fungi,41 OTUs of pathotrophic fungi,and five OTUs of symbiotrophic fungi.The top three most abundant OTUs overall(i.e.,Otu000002,Scopulariopsis acremonium;Otu000018,Alternaria palandui;Otu000034,Aureobasidium pullulans)showed lower abundance in the hind-intestinal segments of bighead carp,suggesting uneven distribution of these fungi in this species.In addition,saprotrophic and pathotrophic fungi were markedly decreased in the hindintestine.It is indicated that the fungal community was not only related to host species specificity but also to the respective physiological functions of different intestinal segments.These findings provide valuable information on the composition,structure,and potential function of the intestinal fungi community associated with different intestinal segments in tilapia and bighead carp under natural conditions,thus highlighting the importance of fungi as an integral part of the inte stinal microbiota in maintaining host health.展开更多
Human noroviruses(HuNoVs)are major foodborne pathogens that cause nonbacterial acute gastroenteritis worldwide.As the tissue-culture system for HuNoVs is not mature enough for routine detection of the virus,detection ...Human noroviruses(HuNoVs)are major foodborne pathogens that cause nonbacterial acute gastroenteritis worldwide.As the tissue-culture system for HuNoVs is not mature enough for routine detection of the virus,detection is mainly dependent on molecular approaches such as reverse transcription polymerase chain reaction(RT-PCR)and reverse transcription quantitative real-time polymerase chain reaction(RTqPCR).The widely used primers and probes for RT-qPCR were established in the early 2000s.As HuNoVs are highly variant viruses,viral genome mutations result in previously designed primers and/or probes that were perfectly matched working less efficiently over time.In this study,a new duplex RT-qPCR(ND-RT-qPCR)was designed for the detection of genogroup Ⅰ(GⅠ)and genogroup Ⅱ(GⅡ)HuNoVs based on an analysis of viral sequences added in the database after 2010.Using long transcribed viral RNAs,the results demonstrate that the sensitivity of ND-RT-qPCR is as low as one genomic copy for both GⅠ and GⅡ HuNoVs.The performance of ND-RT-qPCR was further evaluated by a comparison with the commonly used Kageyama primer/probe sets for RT-qPCR(Kageyama RT-qPCR)for 23 HuNoV-positive clinical samples.All five GⅠ samples were registered as positive by ND-RT-qPCR,whereas only two samples were registered as positive by Kageyama RT-qPCR.All 18 GⅡ samples were registered as positive by ND-RT-qPCR,while 17 samples were registered as positive by Kageyama RT-qPCR.The sensitivity reflected by the quantification cycle(Cq)value was lower in ND-RT-qPCR than in Kageyama RT-qPCR.Our data suggest that ND-RT-qPCR could be a good fit for the detection of current strains of HuNoVs.展开更多
To resolve the impact of transient high frequency signals induced by lightning stroke on the travelling wave protection of transmission line, a novel identification algorithm is proposed. Using the characteristics of ...To resolve the impact of transient high frequency signals induced by lightning stroke on the travelling wave protection of transmission line, a novel identification algorithm is proposed. Using the characteristics of symmetric current wave-form induced by lightning stroke without causing fault and that of asymmetric current waveform generated by fault within a very short time interval, the waveform of transient current above and below time-axes are integrated respec-tively. First, through comparing the relative ratio of them with threshold value, the primary criterion identifying fault and lightning stroke is constructed;Secondly, to improve the reliability of discrimination between lightning stroke with and without causing fault, according to the difference of them, the secondary criterion is also defined. The simulation results and analysis demonstrate that the proposed integral criterions are valid and correct.展开更多
The additive strategy has emerged as an effective approach to improving the performance of perovskite solar cells(PSCs).Herein,a small acceptor-donor-acceptor type molecule indaceno[1,2-b:5,6-b’]dithiophene chloride(...The additive strategy has emerged as an effective approach to improving the performance of perovskite solar cells(PSCs).Herein,a small acceptor-donor-acceptor type molecule indaceno[1,2-b:5,6-b’]dithiophene chloride(IDT-Cl)is designed and synthesized to advance both the efficiency and stability of FA_(0.85)MA_(0.15)PbI_(3)PSCs.Within the IDT-Cl molecule,the S-group with high electron density promotes chemical bonding with the lead cations in the perovskite,resulting in enlarged grain size and smoother surface topography of the perovskite absorber.In addition,the undercoordinated lead ions in the perovskite layer may be passivated by the carbonyl group in the 5-chloroindolin-2-one unit,thereby reducing the number of nonradiative recombination centers.Meanwhile,the IDT-Cl adjusts the energy level mismatch between the perovskite and two adjacent carrier transport layers,leading to easy charge collection.By the multifunctional effect of the IDT-Cl molecule,the modified device yields a high power conversion efficiency(PCE)of 24.46%,8.8%higher than that of the control PSC(22.48%).More importantly,the hydrophobic alkyl side-chain of the IDT-Cl molecule further ensures enhanced humidity stability of the perovskite film and environmental,thermal,and light stabilities of the PSC devices.展开更多
Here,we combined the photon antibunching analysis,fluorescence correlation spectroscopy,and time-domain fluorescence lifetime imaging microscopy(TD-FLIM)to study the emission properties of a representative AIE-lumino...Here,we combined the photon antibunching analysis,fluorescence correlation spectroscopy,and time-domain fluorescence lifetime imaging microscopy(TD-FLIM)to study the emission properties of a representative AIE-luminogen—4,4’-(benzo[c][1,2,5]thiadiazole-4,7-diyl)bis(N,N-diphenylaniline)(TPA-BT)at the single emitter level in a tetrahydrofuran(THF)/water solution where water is a non-solvent for TPA-BT.Our findings suggest that,at a constant water fraction in the solution,the size of TPA-BT aggregates increases with the TPA-BT concentration;TPA-BT aggregates are not a quantum emitter at room temperature in the solution.Moreover,utilizing TD-FLIM and a gel trapping technique allowed us to study the fluorescence lifetime of individual TPA-BT aggregates.Adding a polar solvent like water does not result in an overall decrease in fluorescence lifetime.Rather,it causes the fluorescence lifetime distribution to become wider,and only some molecules experience a decrease in their fluorescence lifetime.These results could represent a step forward in further understanding the photophysics of AIE-luminogens.展开更多
We present an integrated stand-alone software package named KaKs_Calculator 2.0 as an updated version. It incorporates 17 methods for the calculation of nonsynonymous and synonymous substitution rates; among them, we ...We present an integrated stand-alone software package named KaKs_Calculator 2.0 as an updated version. It incorporates 17 methods for the calculation of nonsynonymous and synonymous substitution rates; among them, we added our modified versions of several widely used methods as the gamma series including y-NG, y-LWL, ),-MLWL, y-LPB, y-MLPB, y-YN and y-MYN, which have been demonstrated to perform better under certain conditions than their original forms and are not implemented in the previous version. The package is readily used for the identification of positively selected sites based on a sliding window across the sequences of interests in 5' to 3' direction of protein-coding sequences, and have improved the overall performance on sequence analysis for evolution studies. A toolbox, including C++ and Java source code and executable files on both Windows and Linux platforms together with a user instruction, is downloadable from the website for academic purpose at https://sourceforge.net/projects/kakscalculator2/.展开更多
Symbiotic microorganisms improve nutrient uptake by plants.To initiate mutualistic symbiosis with arbus-cular mycorrhizal(AM)fungi,plants perceive Myc factors,including lipochitooligosaccharides(LCOs)and short-chain c...Symbiotic microorganisms improve nutrient uptake by plants.To initiate mutualistic symbiosis with arbus-cular mycorrhizal(AM)fungi,plants perceive Myc factors,including lipochitooligosaccharides(LCOs)and short-chain chitooligosaccharides(CO4/CO5),secreted by AM fungi.However,the molecular mechanism of Myc factor perception remains elusive.In this study,we identified a heteromer of LysM receptor-like kinases consisting of OsMYR1/OsLYK2 and OsCERK1 that mediates the perception of AM fungi in rice.CO4 directly binds to OsMYR1,promoting the dimerization and phosphorylation of this receptor complex.Compared with control plants,Osmyr1 and Oscerk1 mutant rice plants are less sensitive to Myc factors and show decreased AM colonization.We engineered transgenic rice by expressing chimeric receptors that respectively replaced the ectodomains of OsMYR1 and OsCERK1 with those from the homologous Nod factor receptors MtNFP and MtL YK3 of Medicago truncatula.Transgenic plants displayed increased cal-cium oscillations in response to Nod factors compared with control rice.Our study provides significant mechanistic insights into AM symbiotic signal perception in rice.Expression of chimeric Nod/Myc recep-tors achieves a potentially important step toward generating cereals that host nitrogen-fixing bacteria.展开更多
Polarization imaging finds applications in many areas, such as photoelasticity, ellipsometry, and biomedical imaging. A compact, snapshot, and high-efficiency imaging polarimeter is highly desirable for many applicati...Polarization imaging finds applications in many areas, such as photoelasticity, ellipsometry, and biomedical imaging. A compact, snapshot, and high-efficiency imaging polarimeter is highly desirable for many applications.Here, based on a single multifunctional geometric phase optical element(GPOE), a new method is proposed for high-efficiency snapshot imaging polarimetry. With tailored spatially varying orientation of each anisotropic unit cell, the GPOE works highly efficiently as both a spin sorter and a half-wave plate, enabling snapshot retrieving of a full Stokes vector of incident light. The designed GPOE is implemented in the form of liquid crystal fabricated with a photo-alignment technology, and its application in imaging polarimetry is experimentally demonstrated by retrieving full Stokes parameters of a cylinder vector beam. This method can also work in the form of plasmonic or dielectric metasurfaces, enabling ultra-compact polarization detection systems by monolithic integration with other devices such as metalenses.展开更多
The ratio of nonsynonymous substitution rate (Ka) to synonymous substitution rate (Ks) is widely used as an indicator of selective pressure at sequence level among different species, and diverse mutation models ha...The ratio of nonsynonymous substitution rate (Ka) to synonymous substitution rate (Ks) is widely used as an indicator of selective pressure at sequence level among different species, and diverse mutation models have been incorporated into several computing methods. We have previously developed a new γ-MYN method by capturing a key dynamic evolution trait of DNA nucleotide sequences, in consideration of varying mutation rates across sites. We now report a further improvement of NG, LWL, MLWL, LPB, MLPB, and YN methods based on an introduction of gamma distribution to illustrate the variation of raw mutation rate over sites. The novelty comes in two ways: (1) we incorporate an optimal gamma distribution shape parameter a into γ-NG, γ-LWL, γ-MLWL, γ-LPB, γ-MLPB, and γ-YN methods; (2) we investigate how variable substitution rates affect the methods that adopt different models as well as the interplay among four evolutional features with respect to Ka/Ks computations. Our results suggest that variable substitution rates over sites under negative selection exhibit an opposite effect on estimates compared with those under positive selection. We believe that the sensitivity of our new methods has been improved than that of their original methods under diverse conditions and it is advantageous to introduce novel parameters for Ka/Ks computation.展开更多
A real time PCR assay for the detection of Vibrio para-haemolyticus in seafood samples was developed using a novel specific target and a competitive internal ampli-fication control(IAC).The specificity of this assay w...A real time PCR assay for the detection of Vibrio para-haemolyticus in seafood samples was developed using a novel specific target and a competitive internal ampli-fication control(IAC).The specificity of this assay was evaluated using 390 bacterial strains including V.parahaemolyticus,and other strains belonging to Vibrio and non-Vibrio species.The real time PCR assay un-ambiguously distinguished V.parahaemolyticus with a detection sensitivity of 4.8 fg per PCR with purified genomic DNA or 1 CFU per reaction by counting V.parahaemolyticus colonies.The assays of avoiding interference demonstrated that,even in the presence of 2.1μg genomic DNA or 107 CFU background bacteria,V.parahaemolyticus could still be accurately detected.In addition,the IAC was used to indicate false-negative results,and lower than 94 copies of IAC per reaction had no influence on the detection limit.Ninety-six sea-food samples were tested,of which 58(60.4%)were positive,including 3 false negative results.Conse-quently,the real time PCR assay is effective for the rapid detection of V.parahaemotyticus contaminants in seafood.展开更多
Rotavirus(RV) is a major foodborne pathogen. For RV prevention and control, it is a key to uncover the interaction mechanism between virus and its receptors. However, it is hard to specially purify the viral receptors...Rotavirus(RV) is a major foodborne pathogen. For RV prevention and control, it is a key to uncover the interaction mechanism between virus and its receptors. However, it is hard to specially purify the viral receptors, including histo-blood group antigens(HBGAs). Previously, the protruding domain protein(P protein) of human norovirus(genotype Ⅱ.4) was displayed on the surface of Escherichia coli, and it specifically recognized and captured the viral ligands. In order to further verify the feasibility of the system, P protein was replaced by VP8* of RV(G9 P[8]) in this study. In the system, VP8*could be correctly released by thrombin treatment with antigenicity retaining, which was confirmed by Western blot and Enzyme-Linked Immunosorbent Assays. Type A HBGAs from porcine gastric mucin(PGM) were recognized and captured by this system. From saliva mixture, the captured viral receptor bound with displayed VP8* was confirmed positive with monoclonal antibody against type A HBGAs. It indicated that the target ligands could be easily separated from the complex matrix. These results demonstrate that the bacterial surface display system will be an effective platform to explore viral receptors/ligands from cell lines or food matrix.展开更多
基金supported by the National Natural Science Foundation of China,Nos.81974207(to JH),82001383(to DW)the Special Clinical Research Project of Health Profession of Shanghai Municipal Health Commission,No.20204Y0076(to DW)。
文摘Upregulation of vascular endothelial growth factor A/basic fibroblast growth factor(VEGFA/b FGF)expression in the penumbra of cerebral ischemia can increase vascular volume,reduce lesion volume,and enhance neural cell proliferation and differentiation,thereby exerting neuroprotective effects.However,the beneficial effects of endogenous VEGFA/b FGF are limited as their expression is only transiently increased.In this study,we generated multilayered nanofiber membranes loaded with VEGFA/b FGF using layer-by-layer self-assembly and electrospinning techniques.We found that a membrane containing 10 layers had an ideal ultrastructure and could efficiently and stably release growth factors for more than 1 month.This 10-layered nanofiber membrane promoted brain microvascular endothelial cell tube formation and proliferation,inhibited neuronal apoptosis,upregulated the expression of tight junction proteins,and improved the viability of various cellular components of neurovascular units under conditions of oxygen/glucose deprivation.Furthermore,this nanofiber membrane decreased the expression of Janus kinase-2/signal transducer and activator of transcription-3(JAK2/STAT3),Bax/Bcl-2,and cleaved caspase-3.Therefore,this nanofiber membrane exhibits a neuroprotective effect on oxygen/glucose-deprived neurovascular units by inhibiting the JAK2/STAT3 pathway.
基金supported by the Science and Technology Projects of Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM)No.HRTP202231partially supported by the Agency for Science,Technology,and Research(A*STAR)under AME IRG Grant Nos.A20E5c0095,and CDF Grant No.C210112044。
文摘As a promising counterpart of two-dimensional metamaterials,metasurfaces enable to arbitrarily control the wavefront of light at subwavelength scale and hold promise for planar holography and applicable multiplexing devices.Nevertheless,the degrees of freedom(DoF)to orthogonally multiplex data have been almost exhausted.Compared with state-of-theart methods that extensively employ the orthogonal basis such as wavelength,polarization or orbital angular momentum,we propose an unprecedented method of peristrophic multiplexing by combining the spatial frequency orthogonality with the subwavelength detour phase principle.The orthogonal relationship between the spatial frequency of incident light and the locally shifted building blocks of metasurfaces can be regarded as an additional DoF.We experimentally demonstrate the viability of the multiplexed holograms.Moreover,this newly-explored orthogonality is compatible with conventional DoFs.Our findings will contribute to the development of multiplexing metasurfaces and provide a novel solution to nanophotonics,such as large-capacity chip-scale devices and highly integrated communication.
文摘Aiming at the problem of long time-consuming and low accuracy of existing age estimation approaches,a new age estimation method using Gabor feature fusion,and an improved atomic search algorithm for feature selection is proposed.Firstly,texture features of five scales and eight directions in the face region are extracted by Gabor wavelet transform.The statistical histogram is introduced to encode and fuse the directional index with the largest feature value on Gabor scales.Secondly,a new hybrid feature selection algorithm chaotic improved atom search optimisation with simulated annealing(CIASO-SA)is presented,which is based on an improved atomic search algorithm and the simulated annealing algorithm.Besides,the CIASO-SA algorithm introduces a chaos mechanism during atomic initialisation,significantly improving the convergence speed and accuracy of the algorithm.Finally,a support vector machine(SVM)is used to get classification results of the age group.To verify the performance of the proposed algorithm,face images with three resolutions in the Adience dataset are tested.Using the Gabor real part fusion feature at 48�48 resolution,the average accuracy and 1-off accuracy of age classification exhibit a maximum of 60.4%and 85.9%,respectively.Obtained results prove the superiority of the proposed algorithm over the state-of-the-art methods,which is of great referential value for application to the mobile terminals.
基金funded by The 12th Five Year Plan project of State Key Laboratory of Ore-deposit Geochemistry,Chinese Academy of Sciences(SKLODG-ZY125-04)China Natural Science Foundation(41372105)
文摘Many carbonate-hosted talc mineralization,which are widespread in South China,exclusively developed in Carboniferous dolomitic limestone with many siliceous bands and nodules,and cherts.One of those typical deposits is the Guling talc deposit in Mashan County,central Guangxi province,with a talc reserve of1.51 million tons.Mineral associations in the deposit are sample,mainly including talc and calcite.In this paper,Sm-Nd isotopic system and rare earth elements and yttrium(REE + Y) for the hydrothermal calcite intergrown with talc are used to constrain the age and origin of the talc mineralization.The hydrothermal calcite samples from the deposit display Sm and Nd concentrations ranging from 0.18 to 0.85 and 0.85 to 4.56 ppm,respectively,and variable Sm/Nd ratios of 0.21-0.24.These calcites further yield an Sm-Nd isochron age of 232 ±19 Ma(2a)(MSWD = 0.47) with an concordant initial ^(143)Nd-^(144)Nd ratios of 0.511967 ± 0.000017,which should be interpreted as the mineralization age of the Guling talc deposit.In addition,the calcite samples are enriched in REE with the variable SREE contents ranging from 4.82 to21.50 ppm and display relatively consistent chondritenormalized REE + Y patterns with the LREE enrichment(LREE/HREE=2.00-3.60)and the obvious negative Eu(δEu=0.52-0.68)and Ce(δCe=0.16-0.33)anomalies.The Y/Ho ratios of seven calcites varies from 43.30 to59.34,with a mean value of 49.73.The available mineral associations and REE parameters(i.e.,REE patterns and Y/Ho ratios) of those calcites indicate that the ore-forming fluids of the talc mineralization be probably derived from the meteoric waters,in particular evolved ones in the Karst areas and the ore-forming materials(e.g.,Si and Mg) are likely to be originated from the ore-bearing dolostone in the Yanguan Formation(C_1y) and underlying siliceous rocks in the Liujiang Formation(D_3l).Furthermore,the talc mineralization could take place within a hydrothermal system with relative oxidizing environment and middle temperature,due to the obvious negative Eu and Ce anomalies in the calcites in the Guling deposit.
基金the State Key Laboratory of Ore Deposit Geochemistry, Chinese Academy of Sciences, for supporting this projectfunded by the National Natural Science Foundation of China (Grant No. 41372105)the 12th Five-Year Plan Project of the State Key Laboratory of Ore Deposit Geochemistry, Chinese Academy of Sciences (SKLODGZY125-04)
文摘The Shangling vanadium deposit, which occurs in the Lower Devonian Tangding formation black rock series strata, has V2O5 reserves of more than 1.5 million tons and prospective reserves of more than 2 million tons. Preliminary studies on the occurrence state of vanadium(V) in this deposit have been conducted by artificial heavy minerals concentrates, leaching experiments, scanning and transmission electron microscopy and X-ray powder diffraction.These experiments have revealed no independent vanadium mineral occurrences in the Shangling vanadium deposit and the percentages of water-soluble vanadium, hydrochloric acid soluble vanadium and HF soluble vanadium were1.93 %, 21.42 % and 76.47 %, respectively. Based on our data and earlier research, we estimate that the valences state of V absorbed onto the surface of organic matter or clastic particles are +5 and +4, accounting for 10.00 % and13.35 % of the total amount of V, respectively and the valences state of V that exist in the octahedral crystal lattice of authigenic illite include +3 and +4, accounting for71.64 % and 4.83 % of the total amount of V, respectively.By calculating the correlation between the total organic carbon and V, we infer that after deposition and before entering the crystal lattice of illite, V occurs in the form of humate complex or is adsorbed by organic matter. About4.24 % of the Al is in the octahedral crystal lattice of illite,which was replaced by the vanadium under the metallogenic environments of Shanglin.
文摘The Habo alkaline intrusion, which is located in the south of the Sanjiang area, Yunnan Province, China, is a typical Cenozoic alkaline intrusion. There are a series of small to medium-sized Au and Pb–(Zn) deposits around this intrusion. Those deposits are spatially associated with the Habo alkaline intrusion.(1) The d^(34) S values of sulfides from Au deposits range from-1.91 % to 2.69 %, which are similar to those of Pb–(Zn) deposits(-3.82 % to-0.05 %) and both indicate a much greater contribution from magma.(2) The Habo alkaline intrusion has relatively homogeneous Pb isotopic compositions with^(206)Pb/^(204) Pb ranging from 18.608 to 18.761,^(207)Pb/^(204) Pb from 15.572 to15.722 and^(208)Pb/^(204) Pb from 38.599 to 39.110. These Pb isotope ratios are similar to those of Au deposits, whose^(206)Pb/^(204) Pb range from 18.564 to 18.734,^(207)Pb/^(204) Pb from15.582 to 15.738 and^(208)Pb/^(204) Pb from 38.592 to 39.319.Pb ratios in both the intrusion and Au deposits suggest that Pb mainly derived from the depth, probably represents a mixture of mantle and crust. Pb–(Zn) deposits, however,show a decentralized trait, and most of them are similar to that of the alkaline intrusion with^(206)Pb/^(204) Pb ranging from18.523 to 18.648,^(207)Pb/^(204) Pb from 15.599 to 15.802, and^(208)Pb/^(204) Pb from 38.659 to 39.206.(3) In the plumbotectonic diagram^(207)Pb/^(204) Pb versus^(206)Pb/^(204) Pb, almost all of Au and Pb–(Zn) deposits have the same projection area with the Habo alkaline intrusion, which indicates that thosedeposits almost share the same source with the alkaline intrusion.(4) Isotopic age of the Habo alkaline intrusion is36–33 Ma, which is similar to that of Beiya, whose orerelated alkaline porphyries age is 38–31 Ma and molybdenite Re–Os age is 36.9 Ma. Therefore, along with S–Pb isotope traits, we suggest that the Habo Au and Pb–(Zn)deposits should be typically Ailaoshan-Red River Cenozoicalkaline-related deposits and ore-forming ages of these deposits should be later than that of the Habo alkaline intrusion.
基金The authors acknowledge support from the National Natural Science Foundation of China(62074095/61704101/91733301)the National Key Research and Development Program of China(2016YFA0202403)+3 种基金the Fundamental Research Funds for the Central Universities GK(201903048)the 111 Project(Grant No.B21005)the Fundament Research Funds for the Central University(2019TS004)DNL Cooperation Fund CAS(DNL180311).
文摘Passivating undercoordinated ions is an effective way to reduce the defect densities at the surface and grain boundaries(GBs)of perovskite materials for enhanced photovoltaic performance and stability of perovskite solar cells(PSCs).Here,(BBF)complex is chosen as a multifunctional additive,which contains both C7H9N and BF3 groups working as Lewis base and Lewis acid,respectively,can bond with Pb^(2+)/I^(−) and FA+on the surface and in the GBs in the perovskite film,affording passivation of both cation and anion defects.The synergistic effect of the C7H9N and BF3 complex slows the crystallization during the perovskite film deposition to improve the crystalline quality,which reduces the trap density and the recombination in the perovskite film to suppress nonradiative recombination loss and minimizes moisture permeation to improve the stability of the perovskite material.Meanwhile,such an additive improves the energy-level alignment between the valence band of the perovskite and the highest occupied molecular orbital of the hole-transporting material,Spiro-OMeTAD.Consequently,our work achieves power conversion efficiency of 23.24%,accompanied by enhanced stability under ambient conditions and light illumination and opens a new avenue for improving the performance of PSCs through the use of a multifunctional complex.
基金Supported by Special Fund for Scientific Research of Public Welfare Industry(Agriculture)(201303048)Key Project for Natural Science Foundation of Guangxi(2013GXNSFEA053003)Systematic Research Project of Guangxi Key Laboratory of Aquatic Genetic Breeding and Healthy Aquaculture(13-A-02-01)
文摘Through analysis on water quality,planktonic organism,fish resources,and fish species diversity in Yantan water area,this paper evaluated current situation of quality of fishery ecological environment in Yantan water area. The survey recorded all 52365 fishes and 1410. 2kg catches obtained by fishermen in half a year,and more than 98% catches are small fishes. The Shannon-Weiner diversity index of Yantan water area is 0. 162,Wilhm improvement index is 1. 814,DG- Findex is 0. 083,and the index of fish species diversity is far lower than other water areas. The average quantity per unit of phytoplankton is 1. 0134 million ind. / L,and the average quantity per unit of organisms is 1. 1151 mg / L. The average quantity per unit of zooplankton is 459. 6 ind. / L,and the average quantity per unit of organisms is 0. 6422 mg / L. Evaluation results indicate that water quality and planktonic organism in Yantan water area are basically normal,but fish resources are increasingly exhausted,fish resource composition is not reasonable,and fish species diversity is extremely low. From the perspective of biomanipulation,it is required to restore fishery ecological environment of reservoir area through restoring normal composition of aquatic organisms.
基金This work is partially supported by the National Natural Science Foundation of China (11604219, 61675136, U701661, 61427819, 61138003, 61490712) the Leading talents of Guangdong province program (00201505)+1 种基金 the Natural Science Foundation of Guangdong Province (2016A030312010) Science and Technology Innovation Commission of Shenzhen (KQTD2015071016560101) and Shenzhen Peacock Program (KQTD2017033011044403, KQTD 2017033011044403).
基金the Guangxi Science and Technology Major Project(No.AA17204095-8)the Open Fund of Guangxi Key Laboratory of Aquatic Genetic Breeding and Healthy Aquaculture(No.GXKEYLA2019-05)the China-ASEAN Maritime Cooperation Fund(No.CAMC-2018F)。
文摘Although intestinal fungi play important roles in host health and disease,the composition and diversity of fungal communities remain poorly reported in fish.In this study,fungi in the fore-,mid-,and hindintestine of tilapia(Oreochromis mossambicus)and bighead carp(Aristichthys nobilis)from Hongchaojiang Reservoir in Guangxi,China were investigated by ITS sequencing.Based on this,we obtained 1763478 high-quality tags,which clustered into 1089 operational taxonomic units(OTUs).In total,404 OTUs were annotated,of which 310,68,and 26 belonged to Ascomycota,Basidiomycota,and other,respectively.Results show significant differences in the community composition of intestinal fungi between tilapia and bighead carp but not within their different intestinal segments.Furthermore,154 of the 404 annotated OTUs were considered reliable and were classified into three trophic modes and nine guilds.The three trophic modes consisted of 108 OTUs of saprotrophic fungi,41 OTUs of pathotrophic fungi,and five OTUs of symbiotrophic fungi.The top three most abundant OTUs overall(i.e.,Otu000002,Scopulariopsis acremonium;Otu000018,Alternaria palandui;Otu000034,Aureobasidium pullulans)showed lower abundance in the hind-intestinal segments of bighead carp,suggesting uneven distribution of these fungi in this species.In addition,saprotrophic and pathotrophic fungi were markedly decreased in the hindintestine.It is indicated that the fungal community was not only related to host species specificity but also to the respective physiological functions of different intestinal segments.These findings provide valuable information on the composition,structure,and potential function of the intestinal fungi community associated with different intestinal segments in tilapia and bighead carp under natural conditions,thus highlighting the importance of fungi as an integral part of the inte stinal microbiota in maintaining host health.
基金supported by the Ministry of Science and Technology of China(2017YFC1601200)the National Natural Science Foundation of China(31772078)the Agri-X Interdisciplinary Fund of Shanghai Jiao Tong University(2017).
文摘Human noroviruses(HuNoVs)are major foodborne pathogens that cause nonbacterial acute gastroenteritis worldwide.As the tissue-culture system for HuNoVs is not mature enough for routine detection of the virus,detection is mainly dependent on molecular approaches such as reverse transcription polymerase chain reaction(RT-PCR)and reverse transcription quantitative real-time polymerase chain reaction(RTqPCR).The widely used primers and probes for RT-qPCR were established in the early 2000s.As HuNoVs are highly variant viruses,viral genome mutations result in previously designed primers and/or probes that were perfectly matched working less efficiently over time.In this study,a new duplex RT-qPCR(ND-RT-qPCR)was designed for the detection of genogroup Ⅰ(GⅠ)and genogroup Ⅱ(GⅡ)HuNoVs based on an analysis of viral sequences added in the database after 2010.Using long transcribed viral RNAs,the results demonstrate that the sensitivity of ND-RT-qPCR is as low as one genomic copy for both GⅠ and GⅡ HuNoVs.The performance of ND-RT-qPCR was further evaluated by a comparison with the commonly used Kageyama primer/probe sets for RT-qPCR(Kageyama RT-qPCR)for 23 HuNoV-positive clinical samples.All five GⅠ samples were registered as positive by ND-RT-qPCR,whereas only two samples were registered as positive by Kageyama RT-qPCR.All 18 GⅡ samples were registered as positive by ND-RT-qPCR,while 17 samples were registered as positive by Kageyama RT-qPCR.The sensitivity reflected by the quantification cycle(Cq)value was lower in ND-RT-qPCR than in Kageyama RT-qPCR.Our data suggest that ND-RT-qPCR could be a good fit for the detection of current strains of HuNoVs.
文摘To resolve the impact of transient high frequency signals induced by lightning stroke on the travelling wave protection of transmission line, a novel identification algorithm is proposed. Using the characteristics of symmetric current wave-form induced by lightning stroke without causing fault and that of asymmetric current waveform generated by fault within a very short time interval, the waveform of transient current above and below time-axes are integrated respec-tively. First, through comparing the relative ratio of them with threshold value, the primary criterion identifying fault and lightning stroke is constructed;Secondly, to improve the reliability of discrimination between lightning stroke with and without causing fault, according to the difference of them, the secondary criterion is also defined. The simulation results and analysis demonstrate that the proposed integral criterions are valid and correct.
基金supported by the National Natural Science Foundation of China(62174103,62274104)the Fundamental Research Funds for the Central Universities(GK202103052)+2 种基金the Changjiang Scholar and the Innovative Research Team(IRT_14R33)the 111 Project(B21005)the Chinese National 1000-Talent-Plan Program(111001034)。
文摘The additive strategy has emerged as an effective approach to improving the performance of perovskite solar cells(PSCs).Herein,a small acceptor-donor-acceptor type molecule indaceno[1,2-b:5,6-b’]dithiophene chloride(IDT-Cl)is designed and synthesized to advance both the efficiency and stability of FA_(0.85)MA_(0.15)PbI_(3)PSCs.Within the IDT-Cl molecule,the S-group with high electron density promotes chemical bonding with the lead cations in the perovskite,resulting in enlarged grain size and smoother surface topography of the perovskite absorber.In addition,the undercoordinated lead ions in the perovskite layer may be passivated by the carbonyl group in the 5-chloroindolin-2-one unit,thereby reducing the number of nonradiative recombination centers.Meanwhile,the IDT-Cl adjusts the energy level mismatch between the perovskite and two adjacent carrier transport layers,leading to easy charge collection.By the multifunctional effect of the IDT-Cl molecule,the modified device yields a high power conversion efficiency(PCE)of 24.46%,8.8%higher than that of the control PSC(22.48%).More importantly,the hydrophobic alkyl side-chain of the IDT-Cl molecule further ensures enhanced humidity stability of the perovskite film and environmental,thermal,and light stabilities of the PSC devices.
基金Financial support from the National Natural Science Foundation of China(Nos.22073091 and 21873094)National Key ResearchandDevelopmentProgram ofChina(No.2021YFC2101704)+1 种基金International Science and Technology Cooperation Program of Jilin,China(No.20220508126RC)Key Research Program of Frontier Sciences,Chinese Academy of Sciences(No.ZDBS-LY-SLHO33)is gratefully acknowledged。
文摘Here,we combined the photon antibunching analysis,fluorescence correlation spectroscopy,and time-domain fluorescence lifetime imaging microscopy(TD-FLIM)to study the emission properties of a representative AIE-luminogen—4,4’-(benzo[c][1,2,5]thiadiazole-4,7-diyl)bis(N,N-diphenylaniline)(TPA-BT)at the single emitter level in a tetrahydrofuran(THF)/water solution where water is a non-solvent for TPA-BT.Our findings suggest that,at a constant water fraction in the solution,the size of TPA-BT aggregates increases with the TPA-BT concentration;TPA-BT aggregates are not a quantum emitter at room temperature in the solution.Moreover,utilizing TD-FLIM and a gel trapping technique allowed us to study the fluorescence lifetime of individual TPA-BT aggregates.Adding a polar solvent like water does not result in an overall decrease in fluorescence lifetime.Rather,it causes the fluorescence lifetime distribution to become wider,and only some molecules experience a decrease in their fluorescence lifetime.These results could represent a step forward in further understanding the photophysics of AIE-luminogens.
基金funded by the National Basic Research Program of China (973 Program) to JY (Grant No.2006CB910404)
文摘We present an integrated stand-alone software package named KaKs_Calculator 2.0 as an updated version. It incorporates 17 methods for the calculation of nonsynonymous and synonymous substitution rates; among them, we added our modified versions of several widely used methods as the gamma series including y-NG, y-LWL, ),-MLWL, y-LPB, y-MLPB, y-YN and y-MYN, which have been demonstrated to perform better under certain conditions than their original forms and are not implemented in the previous version. The package is readily used for the identification of positively selected sites based on a sliding window across the sequences of interests in 5' to 3' direction of protein-coding sequences, and have improved the overall performance on sequence analysis for evolution studies. A toolbox, including C++ and Java source code and executable files on both Windows and Linux platforms together with a user instruction, is downloadable from the website for academic purpose at https://sourceforge.net/projects/kakscalculator2/.
基金This work is supported by the NSFC(31730103,31825003,31522007)the National Key Basic Research Programme in China(2015CB158300)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB27040207)the International Partnership Program of Chinese Academy of Sciences(153D31KYSB20160074)the National Key Laboratory of Plant Molecular Genetics to E.W.
文摘Symbiotic microorganisms improve nutrient uptake by plants.To initiate mutualistic symbiosis with arbus-cular mycorrhizal(AM)fungi,plants perceive Myc factors,including lipochitooligosaccharides(LCOs)and short-chain chitooligosaccharides(CO4/CO5),secreted by AM fungi.However,the molecular mechanism of Myc factor perception remains elusive.In this study,we identified a heteromer of LysM receptor-like kinases consisting of OsMYR1/OsLYK2 and OsCERK1 that mediates the perception of AM fungi in rice.CO4 directly binds to OsMYR1,promoting the dimerization and phosphorylation of this receptor complex.Compared with control plants,Osmyr1 and Oscerk1 mutant rice plants are less sensitive to Myc factors and show decreased AM colonization.We engineered transgenic rice by expressing chimeric receptors that respectively replaced the ectodomains of OsMYR1 and OsCERK1 with those from the homologous Nod factor receptors MtNFP and MtL YK3 of Medicago truncatula.Transgenic plants displayed increased cal-cium oscillations in response to Nod factors compared with control rice.Our study provides significant mechanistic insights into AM symbiotic signal perception in rice.Expression of chimeric Nod/Myc recep-tors achieves a potentially important step toward generating cereals that host nitrogen-fixing bacteria.
基金National Natural Science Foundation of China(NSFC)(11604219,61427819,61490712,61605117,91750205,U1701661)Natural Science Foundation of Guangdong Province(2016A030310063,2016A030312010,2017A030313351)+2 种基金Shenzhen Science and Technology Innovation Commission(JCYJ20180507182035270,JCYJ2017818144338999,KQTD2017033011044403,ZDSYS201703031605029)Ministry of Science and Technology of the People’s Republic of China(MOST)(2015CB352004)Guangdong Science and Technology Department(GDSTC)(00201505)
文摘Polarization imaging finds applications in many areas, such as photoelasticity, ellipsometry, and biomedical imaging. A compact, snapshot, and high-efficiency imaging polarimeter is highly desirable for many applications.Here, based on a single multifunctional geometric phase optical element(GPOE), a new method is proposed for high-efficiency snapshot imaging polarimetry. With tailored spatially varying orientation of each anisotropic unit cell, the GPOE works highly efficiently as both a spin sorter and a half-wave plate, enabling snapshot retrieving of a full Stokes vector of incident light. The designed GPOE is implemented in the form of liquid crystal fabricated with a photo-alignment technology, and its application in imaging polarimetry is experimentally demonstrated by retrieving full Stokes parameters of a cylinder vector beam. This method can also work in the form of plasmonic or dielectric metasurfaces, enabling ultra-compact polarization detection systems by monolithic integration with other devices such as metalenses.
基金supported by the National Basic Research Program of China (Grant No. 2006CB910404) awarded to JY
文摘The ratio of nonsynonymous substitution rate (Ka) to synonymous substitution rate (Ks) is widely used as an indicator of selective pressure at sequence level among different species, and diverse mutation models have been incorporated into several computing methods. We have previously developed a new γ-MYN method by capturing a key dynamic evolution trait of DNA nucleotide sequences, in consideration of varying mutation rates across sites. We now report a further improvement of NG, LWL, MLWL, LPB, MLPB, and YN methods based on an introduction of gamma distribution to illustrate the variation of raw mutation rate over sites. The novelty comes in two ways: (1) we incorporate an optimal gamma distribution shape parameter a into γ-NG, γ-LWL, γ-MLWL, γ-LPB, γ-MLPB, and γ-YN methods; (2) we investigate how variable substitution rates affect the methods that adopt different models as well as the interplay among four evolutional features with respect to Ka/Ks computations. Our results suggest that variable substitution rates over sites under negative selection exhibit an opposite effect on estimates compared with those under positive selection. We believe that the sensitivity of our new methods has been improved than that of their original methods under diverse conditions and it is advantageous to introduce novel parameters for Ka/Ks computation.
基金supported by grants from the Ministry of Sci-ence and Technology of China(Nos.2012AA101601 and 2011DFA31220)the National Natural Science Foundation of China(Grant Nos.31171690,30972485,31000779 and U1031003)the Science and Technology Commission of Shanghai Municipality(Nos.10DZ0503500 and 10142201300).
文摘A real time PCR assay for the detection of Vibrio para-haemolyticus in seafood samples was developed using a novel specific target and a competitive internal ampli-fication control(IAC).The specificity of this assay was evaluated using 390 bacterial strains including V.parahaemolyticus,and other strains belonging to Vibrio and non-Vibrio species.The real time PCR assay un-ambiguously distinguished V.parahaemolyticus with a detection sensitivity of 4.8 fg per PCR with purified genomic DNA or 1 CFU per reaction by counting V.parahaemolyticus colonies.The assays of avoiding interference demonstrated that,even in the presence of 2.1μg genomic DNA or 107 CFU background bacteria,V.parahaemolyticus could still be accurately detected.In addition,the IAC was used to indicate false-negative results,and lower than 94 copies of IAC per reaction had no influence on the detection limit.Ninety-six sea-food samples were tested,of which 58(60.4%)were positive,including 3 false negative results.Conse-quently,the real time PCR assay is effective for the rapid detection of V.parahaemotyticus contaminants in seafood.
基金the National Key Research and Development Program of China(2017YFF0210200)the National Natural Science Foundation of China(31772078).
文摘Rotavirus(RV) is a major foodborne pathogen. For RV prevention and control, it is a key to uncover the interaction mechanism between virus and its receptors. However, it is hard to specially purify the viral receptors, including histo-blood group antigens(HBGAs). Previously, the protruding domain protein(P protein) of human norovirus(genotype Ⅱ.4) was displayed on the surface of Escherichia coli, and it specifically recognized and captured the viral ligands. In order to further verify the feasibility of the system, P protein was replaced by VP8* of RV(G9 P[8]) in this study. In the system, VP8*could be correctly released by thrombin treatment with antigenicity retaining, which was confirmed by Western blot and Enzyme-Linked Immunosorbent Assays. Type A HBGAs from porcine gastric mucin(PGM) were recognized and captured by this system. From saliva mixture, the captured viral receptor bound with displayed VP8* was confirmed positive with monoclonal antibody against type A HBGAs. It indicated that the target ligands could be easily separated from the complex matrix. These results demonstrate that the bacterial surface display system will be an effective platform to explore viral receptors/ligands from cell lines or food matrix.