Infection of plum bark necrosis stem pitting associated virus(PBNSPaV)has been reported in many Prunus species in several countries,causing significant economic losses.The very small proteins encoded by plant viruses ...Infection of plum bark necrosis stem pitting associated virus(PBNSPaV)has been reported in many Prunus species in several countries,causing significant economic losses.The very small proteins encoded by plant viruses are often overlooked due to their short sequences and uncertain significance.However,numerous studies have indicated that they might play important roles in the pathogenesis of virus infection.The role of small hydrophobic protein P6,encoded by the open reading frame 2 of PBNSPaV,has not been well explored.In this study,we amplified the P6 fragment from a PBNSPaV isolate by RT-PCR using specific primers and found that it is 174 bp long and encodes a protein of approximately 6.3 kD with a transmembrane domain.Subcellular localization analysis of P6 proteins in tobacco leaves showed that P6 localizes to the cytomembrane and nuclear membrane.To further clarify the pathogenicity of P6 proteins,we constructed a PVX-P6 expression vector by inserting the p6 fragment into a potato virus X(PVX)-based vector and transformed it into Agrobacterium tumefaciens GV3101.Infiltration of Nicotiana benthamiana(N.benthamiana)with the PVX vector-transformed A.tumefaciens led to slight mosaic symptoms at 14 days of post-inoculation.Meanwhile,infiltration with the PVX-P6 vector-transformed A.tumefaciens resulted in no significant symptoms.These results demonstrated that heterologous expression of P6 in N.benthamiana could not enhance the pathogenicity of PVX.Our study indicates that P6 may not be a potential pathogenic factor associate with the causing of symptoms,and the mode of action of PBNSPaV-P6 protein remains to be further studied.展开更多
Accurate soil moisture(SM)prediction is critical for understanding hydrological processes.Physics-based(PB)models exhibit large uncertainties in SM predictions arising from uncertain parameterizations and insufficient...Accurate soil moisture(SM)prediction is critical for understanding hydrological processes.Physics-based(PB)models exhibit large uncertainties in SM predictions arising from uncertain parameterizations and insufficient representation of land-surface processes.In addition to PB models,deep learning(DL)models have been widely used in SM predictions recently.However,few pure DL models have notably high success rates due to lacking physical information.Thus,we developed hybrid models to effectively integrate the outputs of PB models into DL models to improve SM predictions.To this end,we first developed a hybrid model based on the attention mechanism to take advantage of PB models at each forecast time scale(attention model).We further built an ensemble model that combined the advantages of different hybrid schemes(ensemble model).We utilized SM forecasts from the Global Forecast System to enhance the convolutional long short-term memory(ConvLSTM)model for 1–16 days of SM predictions.The performances of the proposed hybrid models were investigated and compared with two existing hybrid models.The results showed that the attention model could leverage benefits of PB models and achieved the best predictability of drought events among the different hybrid models.Moreover,the ensemble model performed best among all hybrid models at all forecast time scales and different soil conditions.It is highlighted that the ensemble model outperformed the pure DL model over 79.5%of in situ stations for 16-day predictions.These findings suggest that our proposed hybrid models can adequately exploit the benefits of PB model outputs to aid DL models in making SM predictions.展开更多
During the course of ionospheric heating experiments, researchers at the European Incoherent Scatter Scientific Association (EISCAT) observed an apparent electron density enhancement. The enhancement extended over a w...During the course of ionospheric heating experiments, researchers at the European Incoherent Scatter Scientific Association (EISCAT) observed an apparent electron density enhancement. The enhancement extended over a wide range of altitudes, above the reflection altitude of the high-frequency pump wave. However, whether this enhancement actually corresponds to a true enhancement in electron density remains an open question. When the dispersion relation of ion acoustic waves is followed, the frequency ratio of the enhanced ion line to the background ion line suggests that the profile of the effective ion mass may have remained unchanged. Furthermore, the solar radio flux and ion drift velocity indicate no significant changes in the ion species and their densities. In conclusion, the electron density enhancement observed at EISCAT should not, in fact, be considered a true enhancement.展开更多
It is now well known that amplitude modulated(AM) high frequency(HF) radio wave transmissions into the ionosphere can be used to generate very/extremely low frequency(VLF/ELF) radio waves using the so-called ‘electro...It is now well known that amplitude modulated(AM) high frequency(HF) radio wave transmissions into the ionosphere can be used to generate very/extremely low frequency(VLF/ELF) radio waves using the so-called ‘electrojet antenna’. Duty cycle and heating frequency are analyzed and discussed with the lower-ionosphere modulated heating model, so as to improve the radiation efficiency of VLF/ELF waves in AM ionospheric heating experiments. Based on numerical simulation, the ranges of parametric selectivity in optimal duty cycle and heating frequency( fHF) are derived. The International Reference Ionosphere 2015(IRI-2015) model and two-parameter model are used to predict background electron density profiles, and optimized ranges of duty cycle for different density profiles are analyzed and compared. The influences of wave polarizations on optimal duty cycle are also discussed. It is shown that intensity of the VLF/ELF equivalent radiation source(M) firstly rises and then falls with the increase of duty cycle. When using the IRI model, M peaks at a duty cycle of 50%, optimally ranging from 40%-70%. For the two-parameter model case, an optimal duty cycle is 40% and the optimized ranges vary from 30%-60%. Heating with an X-mode polarization is more efficient than with the O-mode case in VLF/ELF wave generation. Nevertheless, an optimal duty cycle is almost independent of HF wave polarizations. To obtain better VLF/ELF generation, optional fHFmay be 0.8-0.9 times of foE for the O-mode heating and 0.75-0.85 times for the X-mode polarization case. Finally, the variations of these two parameters in different latitudes are discussed.展开更多
Time-varying channel modeling plays an important role for many applications in time-variant scenarios,while most clustering algorithms focus on static channels and cannot accurately model the channel time-evolution pr...Time-varying channel modeling plays an important role for many applications in time-variant scenarios,while most clustering algorithms focus on static channels and cannot accurately model the channel time-evolution properties.In this paper,a fuzzy clustering algorithm based on multipath component(MPC)trajectory is proposed.Firstly,both the distance and velocity similarities of the MPCs in different snapshots are taken into account to track the MPC trajectory,in which the fuzzy scheme and a kernel function are used to calculate the distance and velocity similarities,respectively.Secondly,a fuzzy MPC trajectory clustering algorithm is proposed to cluster the MPCs in multiple snapshots.The MPCs in a snapshot are clustered according to the membership,which is defined as the probability that a MPC belongs to different clusters.Finally,time-varying channels at 28 GHz are simulated to validate the performance of our proposed algorithm.The results show that our proposed algorithm is able to accurately identify the clusters in time-varying channels compared with the existing clustering algorithms.展开更多
In this study, we present a simulation study of artificial field-aligned irregularities(AFAI) to calculate the scattering coefficient considering a Gaussian autocorrelation function for the wave number spectrum of the...In this study, we present a simulation study of artificial field-aligned irregularities(AFAI) to calculate the scattering coefficient considering a Gaussian autocorrelation function for the wave number spectrum of the density fluctuation. By analyzing variations in the scattering coefficient under different ionospheric backgrounds, the optimal range of the heating frequency was found,which is about 0.9–1 times the critical frequency of the F2 layer. This is especially noticeable as when the heating frequency varies from 0.5 times to 0.9 times of the critical frequency, the scattering coefficient increases by 6.8–16.2 d B. These results should be useful for optimizing the heating frequency in the future artificial field-aligned scattering(AFAS) transmission applications at middle and low latitudes.展开更多
Brassinosteroids(BRs)are a class of steroid hormones with great potential for use in crop improvement.De-repression is usually one of the key events in hormone signaling.However,how the stability of GSK2,the central n...Brassinosteroids(BRs)are a class of steroid hormones with great potential for use in crop improvement.De-repression is usually one of the key events in hormone signaling.However,how the stability of GSK2,the central negative regulator of BR signaling in rice(Oryza sativa),is regulated by BRs remains elusive.Here,we identify the U-box ubiquitin ligase TUD1 as a GSK2-interacting protein by yeast two-hybrid screening.We show that TUD1 is able to directly interact with GSK2 and ubiquitinate the protein.Phenotypes of the tud1 mutant are highly similar to those of plants with constitutively activated GSK2.Consistent with this finding,GSK2 protein accumulates in the tud1 mutant compared with the wild type.In addition,inhibition of BR synthesis promotes GSK2 accumulation and suppresses TUD1 stability.By contrast,BRs can induce GSK2 degradation but promote TUD1 accumulation.Furthermore,the GSK2 degradation process is largely impaired in tud1 in response to BR.In conclusion,our study demonstrates the role of TUD1 in BR-induced GSK2 degradation,thereby advancing our understanding of a critical step in the BR signaling pathway of rice.展开更多
A barley mutant,194,was observed to exhibit a leaf spot phenotype over the whole course of its growing period.In this study,the phenotype and antioxidant competence were studied in the lesion mimic mutant 194.Plant he...A barley mutant,194,was observed to exhibit a leaf spot phenotype over the whole course of its growing period.In this study,the phenotype and antioxidant competence were studied in the lesion mimic mutant 194.Plant height was slightly higher in mutant 194 than in the wild type(WT).In addition,leaf spot per plant in mutant 194 was significantly higher than in WT.Antioxidant competence,as indicated by reactive oxygen species(ROS)accumulation,antioxidant enzyme activity,and the expression of antioxidant enzyme-encoding genes was also assessed in mutant 194.Compared to the WT,mutant 194 displayed a relatively higher accumulation of ROS,accompanied by lower activities of some antioxidant enzymes and downregulation of antioxidant enzyme-encoding genes.This demonstrated reduced antioxidant competence in mutant 194.The results suggested that this lower antioxidant competence of mutant 194 could lead to the accumulation of excessive ROS.This excess of ROS could induce programmed cell death and has the potential to promote disease resistance in mutant 194.展开更多
To understand the anthocyanin characteristics of wine grape varieties,the anthocyanin composition and content of 31 wine grape varieties were analyzed to explore the use of anthocyanins as chemical fingerprints to dis...To understand the anthocyanin characteristics of wine grape varieties,the anthocyanin composition and content of 31 wine grape varieties were analyzed to explore the use of anthocyanins as chemical fingerprints to distinguish varieties.Results showed that a total of 21 anthocyanins were detected in the skins,including cyanidin,delphinidin,petunidin,peonidin and malvidin 3-monoglucosides(or 3,5-diglucosides)along with the corresponding acetyl and p-coumaroyl derivatives.The highest and lowest total amount of anthocyanins were detected in‘Ruby Cabernet’and‘Muscat Rouge’,respectively.In the 21 Vitis vinifera grapes,there were 3~11 monoglucoside anthocyanins detected,however,there were 4 to 9 monoglucoside anthocyanins and 1~7 diglucoside anthocyanins detected in the 10 other species of grapes.Except for‘Zhesexiang’‘Seibel Noir’,‘44-6-7-1’and‘Beibinghong’,the contents of diglucoside anthocyanins in the other six varieties accounted for more than 52%of the total anthocyanins.Except for‘Zhesexiang’,‘Muscat Rouge’and‘Beibinghong’,the content of methylated anthocyanins accounted for more than 75%of total anthocyanins.There were significant differences in the anthocyanin types and contents in the skins among V.vinifera and other grapes.The results of the principal component analysis and the cluster classification of 31 grape varieties(lines)were nearly consistent,which suggested that anthocyanins can be used as chemical fingerprints to distinguish wine grape varieties.展开更多
The oral hexavalent live human-bovine reassortant rotavirus vaccine(RV6)developed by Wuhan Institute of Biological Products Co.,Ltd(WIBP)has finished a randomized,placebo-controlled phase III clinical trial in four pr...The oral hexavalent live human-bovine reassortant rotavirus vaccine(RV6)developed by Wuhan Institute of Biological Products Co.,Ltd(WIBP)has finished a randomized,placebo-controlled phase III clinical trial in four provinces of China in 2021.The trail demonstrated that RV6 has a high vaccine efficacy against the prevalent strains and is safe for use in infants.During the phase III clinical trial(2019–2021),200 rotavirus-positive fecal samples from children with RV gastroenteritis(RVGE)were further studied.Using reverse transcription-polymerase chain reaction and high-throughput sequencing,VP7 and VP4 sequences were obtained and their genetic characteristics,as well as the differences in antigenic epitopes of VP7,were analyzed in detail.Seven rotavirus genotypes were identified.The predominant rotavirus genotype was G9P[8](77.0%),followed by prevalent strains G8P[8](8.0%),G3P[8](3.5%),G3P[9](1.5%),G1P[8](1.0%),G2P[4](1.0%),and G4P[6](1.0%).The amino acid sequence identities of G1,G2,G3,G4,G8,and G9 genotypes of isolates compared to the vaccine strains were 98.8%,98.2%–99.7%,88.4%–99.4%,98.2%,94.2%–100%,and 93.9%–100%,respectively.Notably,the vaccine strains exhibited high similarity in amino acid sequence,with only minor differences in antigenic epitopes compared to the Chinese endemic strains.This supports the potential application of the vaccine in preventing diseases caused by rotaviruses.展开更多
Recent discovery of PYR/PYL/RCAR-type abscisic acid （ABA） receptors has become one of most significant advances in plant science in the past decade. In mammals, endosomal sorting acts as an important pathway to down...Recent discovery of PYR/PYL/RCAR-type abscisic acid （ABA） receptors has become one of most significant advances in plant science in the past decade. In mammals, endosomal sorting acts as an important pathway to downregulate different types of receptors, but its role in plant hormone signaling is poorly understood. Here, we report that an ubiquitin E2-1ike protein, VPS23A, which is a key component of ESCRT-I, negatively regulates ABA signaling. VPS23A has epistatic relationship with PYR/PYL/RCAR-type ABA receptors and disruption of VPS23A enhanced the activity of key kinase OST1 in the ABA signaling pathway under ABA treatment. Moreover, VPS23A interacts with PYR1/PYLs and K63-1inked diubiquitin, and PYL4 possesses K63-1inked ubiquitinated modification in vivo. Further analysis revealed that VPS23A affects the subcellular localization of PYR 1 and the stability of PYL4. Taken together, our results suggest that VPS23A affects PYR1/ PYL4 via vacuole-mediated degradation, providing an advanced understanding of both the turnover of ABA receptors and ESCRTs in plant hormone signaling.展开更多
Abiotic stresses often disrupt protein folding and induce endoplasmic reticulum （ER） stress. There is a sophisticated ER quality control （ERQC） system to mitigate the effects of malfunctioning proteins and maintai...Abiotic stresses often disrupt protein folding and induce endoplasmic reticulum （ER） stress. There is a sophisticated ER quality control （ERQC） system to mitigate the effects of malfunctioning proteins and maintain ER homeostasis. The accumulation of misfolded proteins in the ER activates the unfolded protein response （UPR） to enhance ER protein folding and the degradation of misfolded proteins mediate by ER- associated degradation （ERAD）. That ERQC reduces abiotic stress damage has been well studied in mammals and yeast. However, in plants, both ERAD and UPR have been studied separately and found to be critical for plant abiotic stress tolerance. In this study, we discovered that UPR-associated transcription factors AtbZlP17, AtbZIP28 and AtbZIP60 responded to tunicamycin （TM） and NaCl induced ER stress and subsequently enhanced Arabidopsis thaliana abiotic stress tolerance. They regulated the expression level of ER chaperones and the HRD1-complex components. Moreover, overexpression of AtbZIP17, AtbZIP28 and AtbZIP60 could restore stress tolerance via ERAD in the HRD1-complex mutant hrd3a-2, which suggested that UPR and ERAD have an interactive mechanism in Arabidopsts.展开更多
A randomized,double-blind,placebo-controlled multicenter trial was conducted in healthy Chinese infants to assess the efficacy and safety of a hexavalent live human-bovine reassortant rotavirus vaccine(HRV)against rot...A randomized,double-blind,placebo-controlled multicenter trial was conducted in healthy Chinese infants to assess the efficacy and safety of a hexavalent live human-bovine reassortant rotavirus vaccine(HRV)against rotavirus gastroenteritis(RVGE).A total of 6400 participants aged 6-12 weeks were enrolled and randomly assigned to either HRV(n?3200)or placebo(n?3200)group.All the subjects received three oral doses of vaccine four weeks apart.The vaccine efficacy(VE)against RVGE caused by rotavirus serotypes contained in HRV was evaluated from 14 days after three doses of administration up until the end of the second rotavirus season.VE against severe RVGE,VE against RVGE hospitalization caused by serotypes contained in HRV,and VE against RVGE,severe RVGE,and RVGE hospitalization caused by natural infection of any serotype of rotavirus were also investigated.All adverse events(AEs)were collected for 30 days after each dose.Serious AEs(SAEs)and intussusception cases were collected during the entire study.Our data showed that VE against RVGE caused by serotypes contained in HRV was 69.21%(95%CI:53.31-79.69).VE against severe RVGE and RVGE hospitalization caused by serotypes contained in HRV were 91.36%(95%CI:78.45-96.53)and 89.21%(95%CI:64.51-96.72)respectively.VE against RVGE,severe RVGE,and RVGE hospitalization caused by natural infection of any serotype of rotavirus were 62.88%(95%CI:49.11-72.92),85.51%(95%CI:72.74-92.30)and 83.68%(95%CI:61.34-93.11).Incidences of AEs from the first dose to one month post the third dose in HRV and placebo groups were comparable.There was no significant difference in incidences of SAEs in HRV and placebo groups.This study shows that this hexavalent reassortant rotavirus vaccine is an effective,well-tolerated,and safe vaccine for Chinese infants.展开更多
Extreme environments such as salt stress often increase the reactive oxygen species （ROS） levels （Abogadallah, 2010; Miller et al., 2010）, which cause protein denaturation and damage （Kelsen et al., 2008）. In eu...Extreme environments such as salt stress often increase the reactive oxygen species （ROS） levels （Abogadallah, 2010; Miller et al., 2010）, which cause protein denaturation and damage （Kelsen et al., 2008）. In eukaryotic cells, the endo- plasmic reticulum （ER） lumen is highly oxidative environment, which help newly synthesized proteins form intermolecular or intramolecular disulfide bonds between their cysteine residues. However, the ROS must be regulated according to the folding load to protect the cell from the consequences of oxidative folding.展开更多
基金funded by the National Natural Science Foundation of China(32102143)Shandong Province Natural Sciences Foundation of China(ZR2019PC011 and ZR2020QC122)+1 种基金Scientific Research Foundation for Ph.D.Programs of Zaozhuang University(2018BS040 and 2018BS042)Science and Technology Program of Zaozhuang(2019NS03).
文摘Infection of plum bark necrosis stem pitting associated virus(PBNSPaV)has been reported in many Prunus species in several countries,causing significant economic losses.The very small proteins encoded by plant viruses are often overlooked due to their short sequences and uncertain significance.However,numerous studies have indicated that they might play important roles in the pathogenesis of virus infection.The role of small hydrophobic protein P6,encoded by the open reading frame 2 of PBNSPaV,has not been well explored.In this study,we amplified the P6 fragment from a PBNSPaV isolate by RT-PCR using specific primers and found that it is 174 bp long and encodes a protein of approximately 6.3 kD with a transmembrane domain.Subcellular localization analysis of P6 proteins in tobacco leaves showed that P6 localizes to the cytomembrane and nuclear membrane.To further clarify the pathogenicity of P6 proteins,we constructed a PVX-P6 expression vector by inserting the p6 fragment into a potato virus X(PVX)-based vector and transformed it into Agrobacterium tumefaciens GV3101.Infiltration of Nicotiana benthamiana(N.benthamiana)with the PVX vector-transformed A.tumefaciens led to slight mosaic symptoms at 14 days of post-inoculation.Meanwhile,infiltration with the PVX-P6 vector-transformed A.tumefaciens resulted in no significant symptoms.These results demonstrated that heterologous expression of P6 in N.benthamiana could not enhance the pathogenicity of PVX.Our study indicates that P6 may not be a potential pathogenic factor associate with the causing of symptoms,and the mode of action of PBNSPaV-P6 protein remains to be further studied.
基金supported by the Natural Science Foundation of China(Grant Nos.42088101 and 42205149)Zhongwang WEI was supported by the Natural Science Foundation of China(Grant No.42075158)+1 种基金Wei SHANGGUAN was supported by the Natural Science Foundation of China(Grant No.41975122)Yonggen ZHANG was supported by the National Natural Science Foundation of Tianjin(Grant No.20JCQNJC01660).
文摘Accurate soil moisture(SM)prediction is critical for understanding hydrological processes.Physics-based(PB)models exhibit large uncertainties in SM predictions arising from uncertain parameterizations and insufficient representation of land-surface processes.In addition to PB models,deep learning(DL)models have been widely used in SM predictions recently.However,few pure DL models have notably high success rates due to lacking physical information.Thus,we developed hybrid models to effectively integrate the outputs of PB models into DL models to improve SM predictions.To this end,we first developed a hybrid model based on the attention mechanism to take advantage of PB models at each forecast time scale(attention model).We further built an ensemble model that combined the advantages of different hybrid schemes(ensemble model).We utilized SM forecasts from the Global Forecast System to enhance the convolutional long short-term memory(ConvLSTM)model for 1–16 days of SM predictions.The performances of the proposed hybrid models were investigated and compared with two existing hybrid models.The results showed that the attention model could leverage benefits of PB models and achieved the best predictability of drought events among the different hybrid models.Moreover,the ensemble model performed best among all hybrid models at all forecast time scales and different soil conditions.It is highlighted that the ensemble model outperformed the pure DL model over 79.5%of in situ stations for 16-day predictions.These findings suggest that our proposed hybrid models can adequately exploit the benefits of PB model outputs to aid DL models in making SM predictions.
基金supported by research organizations in China (CRIRP), Finland (SA), Japan (NIPR and STEL), Norway (NFR), Sweden (VR), and the United Kingdom (NERC)supported by the Taishan Scholars Project of Shandong Province (Grant No. ts20190968)supported by the foundation of National Key Laboratory of Electromagnetic Environment (Grant No. 6142403230303)
文摘During the course of ionospheric heating experiments, researchers at the European Incoherent Scatter Scientific Association (EISCAT) observed an apparent electron density enhancement. The enhancement extended over a wide range of altitudes, above the reflection altitude of the high-frequency pump wave. However, whether this enhancement actually corresponds to a true enhancement in electron density remains an open question. When the dispersion relation of ion acoustic waves is followed, the frequency ratio of the enhanced ion line to the background ion line suggests that the profile of the effective ion mass may have remained unchanged. Furthermore, the solar radio flux and ion drift velocity indicate no significant changes in the ion species and their densities. In conclusion, the electron density enhancement observed at EISCAT should not, in fact, be considered a true enhancement.
基金supported by the Innovation Fund of China Electronics Technology Group Corporation (No. KJ1602004)
文摘It is now well known that amplitude modulated(AM) high frequency(HF) radio wave transmissions into the ionosphere can be used to generate very/extremely low frequency(VLF/ELF) radio waves using the so-called ‘electrojet antenna’. Duty cycle and heating frequency are analyzed and discussed with the lower-ionosphere modulated heating model, so as to improve the radiation efficiency of VLF/ELF waves in AM ionospheric heating experiments. Based on numerical simulation, the ranges of parametric selectivity in optimal duty cycle and heating frequency( fHF) are derived. The International Reference Ionosphere 2015(IRI-2015) model and two-parameter model are used to predict background electron density profiles, and optimized ranges of duty cycle for different density profiles are analyzed and compared. The influences of wave polarizations on optimal duty cycle are also discussed. It is shown that intensity of the VLF/ELF equivalent radiation source(M) firstly rises and then falls with the increase of duty cycle. When using the IRI model, M peaks at a duty cycle of 50%, optimally ranging from 40%-70%. For the two-parameter model case, an optimal duty cycle is 40% and the optimized ranges vary from 30%-60%. Heating with an X-mode polarization is more efficient than with the O-mode case in VLF/ELF wave generation. Nevertheless, an optimal duty cycle is almost independent of HF wave polarizations. To obtain better VLF/ELF generation, optional fHFmay be 0.8-0.9 times of foE for the O-mode heating and 0.75-0.85 times for the X-mode polarization case. Finally, the variations of these two parameters in different latitudes are discussed.
基金supported by the National Key Laboratory of Electromagnetic Environment(No.202101004)the National Nature Science of China(NSFC)(No.61931001),respectively。
文摘Time-varying channel modeling plays an important role for many applications in time-variant scenarios,while most clustering algorithms focus on static channels and cannot accurately model the channel time-evolution properties.In this paper,a fuzzy clustering algorithm based on multipath component(MPC)trajectory is proposed.Firstly,both the distance and velocity similarities of the MPCs in different snapshots are taken into account to track the MPC trajectory,in which the fuzzy scheme and a kernel function are used to calculate the distance and velocity similarities,respectively.Secondly,a fuzzy MPC trajectory clustering algorithm is proposed to cluster the MPCs in multiple snapshots.The MPCs in a snapshot are clustered according to the membership,which is defined as the probability that a MPC belongs to different clusters.Finally,time-varying channels at 28 GHz are simulated to validate the performance of our proposed algorithm.The results show that our proposed algorithm is able to accurately identify the clusters in time-varying channels compared with the existing clustering algorithms.
基金supported by the Innovation Foundation of the China Electronics Technology Group Corporation (No. KJ1602004)
文摘In this study, we present a simulation study of artificial field-aligned irregularities(AFAI) to calculate the scattering coefficient considering a Gaussian autocorrelation function for the wave number spectrum of the density fluctuation. By analyzing variations in the scattering coefficient under different ionospheric backgrounds, the optimal range of the heating frequency was found,which is about 0.9–1 times the critical frequency of the F2 layer. This is especially noticeable as when the heating frequency varies from 0.5 times to 0.9 times of the critical frequency, the scattering coefficient increases by 6.8–16.2 d B. These results should be useful for optimizing the heating frequency in the future artificial field-aligned scattering(AFAS) transmission applications at middle and low latitudes.
基金supported by the Hainan Yazhou Bay Seed Laboratory(B21HJ0215)the National Natural Science Foundation of China(nos.U21A20208,31900177,31901534,31871587)+1 种基金the Central Publicinterest Scientific Institution Basal Research Fund(no.S2022ZD02)D.L.was funded by the China Postdoctoral Science Foundation(2020M670548).
文摘Brassinosteroids(BRs)are a class of steroid hormones with great potential for use in crop improvement.De-repression is usually one of the key events in hormone signaling.However,how the stability of GSK2,the central negative regulator of BR signaling in rice(Oryza sativa),is regulated by BRs remains elusive.Here,we identify the U-box ubiquitin ligase TUD1 as a GSK2-interacting protein by yeast two-hybrid screening.We show that TUD1 is able to directly interact with GSK2 and ubiquitinate the protein.Phenotypes of the tud1 mutant are highly similar to those of plants with constitutively activated GSK2.Consistent with this finding,GSK2 protein accumulates in the tud1 mutant compared with the wild type.In addition,inhibition of BR synthesis promotes GSK2 accumulation and suppresses TUD1 stability.By contrast,BRs can induce GSK2 degradation but promote TUD1 accumulation.Furthermore,the GSK2 degradation process is largely impaired in tud1 in response to BR.In conclusion,our study demonstrates the role of TUD1 in BR-induced GSK2 degradation,thereby advancing our understanding of a critical step in the BR signaling pathway of rice.
文摘A barley mutant,194,was observed to exhibit a leaf spot phenotype over the whole course of its growing period.In this study,the phenotype and antioxidant competence were studied in the lesion mimic mutant 194.Plant height was slightly higher in mutant 194 than in the wild type(WT).In addition,leaf spot per plant in mutant 194 was significantly higher than in WT.Antioxidant competence,as indicated by reactive oxygen species(ROS)accumulation,antioxidant enzyme activity,and the expression of antioxidant enzyme-encoding genes was also assessed in mutant 194.Compared to the WT,mutant 194 displayed a relatively higher accumulation of ROS,accompanied by lower activities of some antioxidant enzymes and downregulation of antioxidant enzyme-encoding genes.This demonstrated reduced antioxidant competence in mutant 194.The results suggested that this lower antioxidant competence of mutant 194 could lead to the accumulation of excessive ROS.This excess of ROS could induce programmed cell death and has the potential to promote disease resistance in mutant 194.
基金This work was financially supported by China Natural Science Foundation of Shandong Province(ZR2019BC092)Doctoral Research Fundation of Zaozhuang University(1020707)Shanxi Provincial Key Research and Development Project(201603D21105).
文摘To understand the anthocyanin characteristics of wine grape varieties,the anthocyanin composition and content of 31 wine grape varieties were analyzed to explore the use of anthocyanins as chemical fingerprints to distinguish varieties.Results showed that a total of 21 anthocyanins were detected in the skins,including cyanidin,delphinidin,petunidin,peonidin and malvidin 3-monoglucosides(or 3,5-diglucosides)along with the corresponding acetyl and p-coumaroyl derivatives.The highest and lowest total amount of anthocyanins were detected in‘Ruby Cabernet’and‘Muscat Rouge’,respectively.In the 21 Vitis vinifera grapes,there were 3~11 monoglucoside anthocyanins detected,however,there were 4 to 9 monoglucoside anthocyanins and 1~7 diglucoside anthocyanins detected in the 10 other species of grapes.Except for‘Zhesexiang’‘Seibel Noir’,‘44-6-7-1’and‘Beibinghong’,the contents of diglucoside anthocyanins in the other six varieties accounted for more than 52%of the total anthocyanins.Except for‘Zhesexiang’,‘Muscat Rouge’and‘Beibinghong’,the content of methylated anthocyanins accounted for more than 75%of total anthocyanins.There were significant differences in the anthocyanin types and contents in the skins among V.vinifera and other grapes.The results of the principal component analysis and the cluster classification of 31 grape varieties(lines)were nearly consistent,which suggested that anthocyanins can be used as chemical fingerprints to distinguish wine grape varieties.
基金the National Health Committee of the People's Republic of China(grant number:2019ZX09302059).
文摘The oral hexavalent live human-bovine reassortant rotavirus vaccine(RV6)developed by Wuhan Institute of Biological Products Co.,Ltd(WIBP)has finished a randomized,placebo-controlled phase III clinical trial in four provinces of China in 2021.The trail demonstrated that RV6 has a high vaccine efficacy against the prevalent strains and is safe for use in infants.During the phase III clinical trial(2019–2021),200 rotavirus-positive fecal samples from children with RV gastroenteritis(RVGE)were further studied.Using reverse transcription-polymerase chain reaction and high-throughput sequencing,VP7 and VP4 sequences were obtained and their genetic characteristics,as well as the differences in antigenic epitopes of VP7,were analyzed in detail.Seven rotavirus genotypes were identified.The predominant rotavirus genotype was G9P[8](77.0%),followed by prevalent strains G8P[8](8.0%),G3P[8](3.5%),G3P[9](1.5%),G1P[8](1.0%),G2P[4](1.0%),and G4P[6](1.0%).The amino acid sequence identities of G1,G2,G3,G4,G8,and G9 genotypes of isolates compared to the vaccine strains were 98.8%,98.2%–99.7%,88.4%–99.4%,98.2%,94.2%–100%,and 93.9%–100%,respectively.Notably,the vaccine strains exhibited high similarity in amino acid sequence,with only minor differences in antigenic epitopes compared to the Chinese endemic strains.This supports the potential application of the vaccine in preventing diseases caused by rotaviruses.
文摘Recent discovery of PYR/PYL/RCAR-type abscisic acid （ABA） receptors has become one of most significant advances in plant science in the past decade. In mammals, endosomal sorting acts as an important pathway to downregulate different types of receptors, but its role in plant hormone signaling is poorly understood. Here, we report that an ubiquitin E2-1ike protein, VPS23A, which is a key component of ESCRT-I, negatively regulates ABA signaling. VPS23A has epistatic relationship with PYR/PYL/RCAR-type ABA receptors and disruption of VPS23A enhanced the activity of key kinase OST1 in the ABA signaling pathway under ABA treatment. Moreover, VPS23A interacts with PYR1/PYLs and K63-1inked diubiquitin, and PYL4 possesses K63-1inked ubiquitinated modification in vivo. Further analysis revealed that VPS23A affects the subcellular localization of PYR 1 and the stability of PYL4. Taken together, our results suggest that VPS23A affects PYR1/ PYL4 via vacuole-mediated degradation, providing an advanced understanding of both the turnover of ABA receptors and ESCRTs in plant hormone signaling.
基金supported by grants from the National Science Foundation of China(NSFC31030047)the National Basic Research Program of China(973 Program,2011CB915402,to Q. Xie)
文摘Abiotic stresses often disrupt protein folding and induce endoplasmic reticulum （ER） stress. There is a sophisticated ER quality control （ERQC） system to mitigate the effects of malfunctioning proteins and maintain ER homeostasis. The accumulation of misfolded proteins in the ER activates the unfolded protein response （UPR） to enhance ER protein folding and the degradation of misfolded proteins mediate by ER- associated degradation （ERAD）. That ERQC reduces abiotic stress damage has been well studied in mammals and yeast. However, in plants, both ERAD and UPR have been studied separately and found to be critical for plant abiotic stress tolerance. In this study, we discovered that UPR-associated transcription factors AtbZlP17, AtbZIP28 and AtbZIP60 responded to tunicamycin （TM） and NaCl induced ER stress and subsequently enhanced Arabidopsis thaliana abiotic stress tolerance. They regulated the expression level of ER chaperones and the HRD1-complex components. Moreover, overexpression of AtbZIP17, AtbZIP28 and AtbZIP60 could restore stress tolerance via ERAD in the HRD1-complex mutant hrd3a-2, which suggested that UPR and ERAD have an interactive mechanism in Arabidopsts.
基金supported by National Health Commission of the People’s Republic of China (grant number:2019ZX09302059)sponsored and funded by Wuhan Institute of Biological Products Co.,Ltd.,Hubei,China
文摘A randomized,double-blind,placebo-controlled multicenter trial was conducted in healthy Chinese infants to assess the efficacy and safety of a hexavalent live human-bovine reassortant rotavirus vaccine(HRV)against rotavirus gastroenteritis(RVGE).A total of 6400 participants aged 6-12 weeks were enrolled and randomly assigned to either HRV(n?3200)or placebo(n?3200)group.All the subjects received three oral doses of vaccine four weeks apart.The vaccine efficacy(VE)against RVGE caused by rotavirus serotypes contained in HRV was evaluated from 14 days after three doses of administration up until the end of the second rotavirus season.VE against severe RVGE,VE against RVGE hospitalization caused by serotypes contained in HRV,and VE against RVGE,severe RVGE,and RVGE hospitalization caused by natural infection of any serotype of rotavirus were also investigated.All adverse events(AEs)were collected for 30 days after each dose.Serious AEs(SAEs)and intussusception cases were collected during the entire study.Our data showed that VE against RVGE caused by serotypes contained in HRV was 69.21%(95%CI:53.31-79.69).VE against severe RVGE and RVGE hospitalization caused by serotypes contained in HRV were 91.36%(95%CI:78.45-96.53)and 89.21%(95%CI:64.51-96.72)respectively.VE against RVGE,severe RVGE,and RVGE hospitalization caused by natural infection of any serotype of rotavirus were 62.88%(95%CI:49.11-72.92),85.51%(95%CI:72.74-92.30)and 83.68%(95%CI:61.34-93.11).Incidences of AEs from the first dose to one month post the third dose in HRV and placebo groups were comparable.There was no significant difference in incidences of SAEs in HRV and placebo groups.This study shows that this hexavalent reassortant rotavirus vaccine is an effective,well-tolerated,and safe vaccine for Chinese infants.
基金supported by the grants from the National Science Foundation of China NSFC(No.31030047)the National Basic Research Program of China(973 Program, No.2011CB915402)the State Key Laboratory of Plant Genomics of China(No.2009A0714-05)
文摘Extreme environments such as salt stress often increase the reactive oxygen species （ROS） levels （Abogadallah, 2010; Miller et al., 2010）, which cause protein denaturation and damage （Kelsen et al., 2008）. In eukaryotic cells, the endo- plasmic reticulum （ER） lumen is highly oxidative environment, which help newly synthesized proteins form intermolecular or intramolecular disulfide bonds between their cysteine residues. However, the ROS must be regulated according to the folding load to protect the cell from the consequences of oxidative folding.
