Although oxymatrine(OMT) has been shown to directly inhibit the replication of hepatitis B virus(HBV) in vitro, limited research has been done with this drug in vivo. In the present study, the antiviral effect of OMT ...Although oxymatrine(OMT) has been shown to directly inhibit the replication of hepatitis B virus(HBV) in vitro, limited research has been done with this drug in vivo. In the present study, the antiviral effect of OMT was investigated in an immunocompetent mouse model of chronic HBV infection.The infection was achieved by tail vein injection of a large volume of DNA solution. OMT(2.2, 6.7 and20 mg/kg) was administered by daily intraperitoneal injection for 6 weeks. The efficacy of OMT was evaluated by the levels of HBV DNA, hepatitis B surface antigen(HBs Ag), hepatitis B e antigen(HBe Ag)and hepatitis B core antigen(HBc Ag). The immunoregulatory activity of OMT was evaluated by serum ELISA and flow cytometry. Results shows that OMT at 20 mg/kg inhibited HBV replication, and it was more efficient than entecavir(ETV) in the elimination of serum HBs Ag and intrahepatic HBc Ag. Inaddition, OMT accelerated the production of interferon-γ(IFN-γ) in a dose-dependent manner in CD4^+T cells. Our findings demonstrate the beneficial effects of OMT on the enhancement of immunological function and in the control of HBV antigens. The findings suggest this drug to be a good antiviral therapeutic candidate for the treatment of HBV infection.展开更多
Background It remains almost a helpless situation for the recurrent implantation failure and pregnancy loss caused by endometrial injury at present. The purpose of this study was to develop a rabbit model of endometri...Background It remains almost a helpless situation for the recurrent implantation failure and pregnancy loss caused by endometrial injury at present. The purpose of this study was to develop a rabbit model of endometrial mechanical injury that could provide a research platform for this difficult clinical predicament. Methods Three experiments were conducted. Experiment 1： Curettages in both uterus horns and copper wire inserting after curettage （double-injury） in one horn. The histological changes were monitored at 0, 24, 48, 72 hours, as well as in 1 and 2 weeks after operation. Experiment 2： Direct copper wire inserting in one horn and double-injury in other horn. The wires in both horns were removed after 2 weeks.展开更多
X-ray diffraction(XRD)data acquisition and analysis is among the most time-consuming steps in the development cycle of novel thin-film materials.We propose a machine learning-enabled approach to predict crystallograph...X-ray diffraction(XRD)data acquisition and analysis is among the most time-consuming steps in the development cycle of novel thin-film materials.We propose a machine learning-enabled approach to predict crystallographic dimensionality and space group from a limited number of thin-film XRD patterns.We overcome the scarce data problem intrinsic to novel materials development by coupling a supervised machine learning approach with a model-agnostic,physics-informed data augmentation strategy using simulated data from the Inorganic Crystal Structure Database(ICSD)and experimental data.As a test case,115 thin-film metalhalides spanning three dimensionalities and seven space groups are synthesized and classified.After testing various algorithms,we develop and implement an all convolutional neural network,with cross-validated accuracies for dimensionality and space group classification of 93 and 89%,respectively.We propose average class activation maps,computed from a global average pooling layer,to allow high model interpretability by human experimentalists,elucidating the root causes of misclassification.Finally,we systematically evaluate the maximum XRD pattern step size(data acquisition rate)before loss of predictive accuracy occurs,and determine it to be 0.16°2θ,which enables an XRD pattern to be obtained and classified in 5.5 min or less.展开更多
Background The purpose of this retrospective study was to compare the surgical outcomes of simple discectomy and instrumented posterior lumbar interbody fusion （iPLIF） in patients with lumbar disc herniation and Mod...Background The purpose of this retrospective study was to compare the surgical outcomes of simple discectomy and instrumented posterior lumbar interbody fusion （iPLIF） in patients with lumbar disc herniation and Modic endplate changes.Our hypothesis was that iPLIF could provide better outcome for patients with refractory lumbar disc herniation and Modic changes （LDH-MC）.Methods Ninety-one patients with single-segment LDH-MC were recruited.All patients experienced low back pain as well as radicular leg pain,and low back pain was more severe than leg pain.Forty-seven patients were treated with discectomy and 44 were treated with iPLIE The outcomes of both low back pain and radicular leg pain using visual analogue scale （VAS） as well as the clinical outcome related to low back pain using Japanese Orthopaedic Association （JOA） score were assessed before and 18 months after surgery,respectively.Results Both low back and leg pain were significantly improved 18 months after simple discectomy and iPLIE Compared to patients undergoing simple discectomy,low back pain was significantly reduced in patients undergoing iPLIE but there was no significant difference in leg pain between two groups.Solid fusion was achieved in all patients who underwent iPLIF.Conclusions In patients with LDH-MC,iPLIF can yield significantly superior outcome on the relief of low back pain compared to simple discectomy.Simple discectomy can relieve radicular leg pain as efficient as iPLIE Accordingly,iPLIF seems to be a reliable treatment for patients with LDH-MC and predominant low back pain.展开更多
According to statistic data,machinery faults contribute to largest proportion of High-voltage circuit breaker failures,and traditional maintenance methods exist some disadvantages for that issue.Therefore,based on the...According to statistic data,machinery faults contribute to largest proportion of High-voltage circuit breaker failures,and traditional maintenance methods exist some disadvantages for that issue.Therefore,based on the wavelet packet decomposition approach and support vector machines,a new diagnosis model is proposed for such fault diagnoses in this study.The vibration eigenvalue extraction is analyzed through wavelet packet decomposition,and a four-layer support vector machine is constituted as a fault classifier.The Gaussian radial basis function is employed as the kernel function for the classifier.The penalty parameter c and kernel parameterδof the support vector machine are vital for the diagnostic accuracy,and these parameters must be carefully predetermined.Thus,a particle swarm optimizationsupport vector machine model is developed in which the optimal parameters c andδfor the support vector machine in each layer are determined by the particle swarm algorithm.The validity of this fault diagnosis model is determined with a real dataset from the operation experiment.Moreover,comparative investigations of fault diagnosis experiments with a normal support vector machine and a particle swarm optimization back-propagation neural network are also implemented.The results indicate that the proposed fault diagnosis model yields better accuracy and e-ciency than these other models.展开更多
Simultaneous pyridine biodegradation and nitrogen removal were successfully achieved in a sequencing batch reactor（SBR） based on aerobic granules. In a typical SBR cycle, nitritation occurred obviously after the maj...Simultaneous pyridine biodegradation and nitrogen removal were successfully achieved in a sequencing batch reactor（SBR） based on aerobic granules. In a typical SBR cycle, nitritation occurred obviously after the majority of pyridine was removed, while denitrification occurred at early stage of the cycle when oxygen consumption was aggravated. The effect of several key operation parameters, i.e., air flow rate, influent NH4~＋-N concentration,influent p H and pyridine concentration, on nitritation, pyridine degradation and total nitrogen（TN） removal, was systematically investigated. The results indicated that high air flow rate had a positive effect on both pyridine degradation and nitritation but a negative impact of overhigh air flow rate. With the increase of NH4~＋ dosage, both nitritation and TN removal could be severely inhibited. Slightly alkaline condition, i.e., pH 7.0–8.0, was beneficial for both pyridine degradation and nitritation. High pyridine dosage often resulted in the delay of both pyridine degradation and nitritation. Besides, extracellular polymeric substances production was affected by air flow rate, NH4~＋ dosage, pyridine dosage and p H.In addition, high-throughput sequencing analysis demonstrated that Bdellovibrio and Paracoccus were the dominant species in the aerobic granulation system. Coexistence of pyridine degrader, nitrification related species, denitrification related species, polymeric substances producer and self-aggregation related species was also confirmed by highthroughput sequencing.展开更多
Zanthoxylum bungeanum is an important spice and medicinal plant that is unique for its accumulation of abundant secondary metabolites,which create a characteristic aroma and tingling sensation in the mouth.Owing to th...Zanthoxylum bungeanum is an important spice and medicinal plant that is unique for its accumulation of abundant secondary metabolites,which create a characteristic aroma and tingling sensation in the mouth.Owing to the high proportion of repetitive sequences,high heterozygosity,and increased chromosome number of Z.bungeanum,the assembly of its chromosomal pseudomolecules is extremely challenging.Here,we present a genome sequence for Z.bungeanum,with a dramatically expanded size of 4.23 Gb,assembled into 68 chromosomes.This genome is approximately tenfold larger than that of its close relative Citrus sinensis.After the divergence of Zanthoxylum and Citrus,the lineage-specific whole-genome duplication event q-WGD approximately 26.8 million years ago(MYA)and the recent transposable element(TE)burst~6.41 MYA account for the substantial genome expansion in Z.bungeanum.The independent Zanthoxylum-specific WGD event was followed by numerous fusion/fission events that shaped the genomic architecture.Integrative genomic and transcriptomic analyses suggested that prominent speciesspecific gene family expansions and changes in gene expression have shaped the biosynthesis of sanshools,terpenoids,and anthocyanins,which contribute to the special flavor and appearance of Z.bungeanum.In summary,the reference genome provides a valuable model for studying the impact of WGDs with recent TE activity on gene gain and loss and genome reconstruction and provides resources to accelerate Zanthoxylum improvement.展开更多
Ni-Co bimetallic catalysts with different Ni/Co content were derived from cold plasma jet decomposition and reduction of hydrotalcite-like compounds containing Ni,Co,Mg and Al,and their catalytic performance was inves...Ni-Co bimetallic catalysts with different Ni/Co content were derived from cold plasma jet decomposition and reduction of hydrotalcite-like compounds containing Ni,Co,Mg and Al,and their catalytic performance was investigated with dry reforming of methane.Experimental results showed that the hydrotalcite-like precursors could be completely decomposed and partly reduced by cold plasma jet,and the Nicontained catalysts exhibited much higher activity than the catalyst without Ni.Especially,the catalyst with Ni/Co ratio of 8/2 achieved not only the highest conversions of 80.3%and 69.3%for CH4 and CO2,respectively,but also the best stability in 100 h testing.The catalysts were characterized by XRD,XPS,TEM and N2 adsorption techniques,and the results showed that the better performance of the 8Ni2Co bimetallic catalyst was attributed to its higher metal dispersion,smaller metal particle size,as well as the interaction effect between Ni and Co,which were brought by the special catalyst preparation method.展开更多
Chinese pepper,mainly including Zanthoxylum bungeanum and Zanthoxylum armatum,is an economically important crop popular in Asian countries due to its unique taste characteristics and potential medical uses.Numerous cu...Chinese pepper,mainly including Zanthoxylum bungeanum and Zanthoxylum armatum,is an economically important crop popular in Asian countries due to its unique taste characteristics and potential medical uses.Numerous cultivars of Chinese pepper have been developed in China through long-term domestication.To better understand the population structure,demographic history,and speciation of Chinese pepper,we performed a comprehensive analysis at a genome-wide level by analyzing 38,395 genomic SNPs that were identified in 112 cultivated and wild accessions using a high-throughput genomewide genotyping-by-sequencing(GBS)approach.Our analysis provides genetic evidence of multiple splitting events occurring between and within species,resulting in at least four clades in Z.bungeanum and two clades in Z.armatum.Despite no evidence of recent admixture between species,we detected substantial gene flow within species.Estimates of demographic dynamics and species distribution modeling suggest that climatic oscillations during the Pleistocene(including the Penultimate Glaciation and the Last Glacial Maximum)and recent domestication events together shaped the demography and evolution of Chinese pepper.Our analyses also suggest that southeastern Gansu province is the most likely origin of Z.bungeanum in China.These findings provide comprehensive insights into genetic diversity,population structure,demography,and adaptation in Zanthoxylum.展开更多
Trachoma is one of the most widespread blinding eye diseases, which is harmful to human visual health. The efforts to prevent and control trachoma in China can be divided into three periods, i.e., highly epidemic peri...Trachoma is one of the most widespread blinding eye diseases, which is harmful to human visual health. The efforts to prevent and control trachoma in China can be divided into three periods, i.e., highly epidemic period, research on pathogenesis and control of trachoma, and blinding trachoma elimination and epidemiological evaluation. In 1956, Prof. Feifan Tang and Xiaolou Zhang first discovered and isolated Chlamydia trachomatis, which clarified the cause of trachoma, and kick-started a fresh chapter in trachoma research, prevention, and control around the world. Although, the prevalence of trachoma differed in different areas, the average prevalence once exceeded 50% and was as high as 90% in some areas before and at early liberation of China. Therefore, the government-led efforts were made to comprehensively prevent and control trachoma, including development of National Plan for the Prevention and Control of Trachoma, nationwide screening and treatment of trachoma, implementation of National Patriotic Health Campaign and improvement of water supply and lavatories. After decades of effort, China reached the goal of eliminating blinding trachoma in 2015. China has gained remarkable achievements in the prevention and treatment of trachoma, making outstanding contributions toward the goal of eliminating trachoma worldwide. The research, prevention, and control of trachoma in China were reviewed in this paper.展开更多
Heading date is a critical trait that determines the regional adaptability and grain productivity of many crops.Although rice is a facultative short-day plant,its domestication led to the Ghd7-Ehd1-Hd3a/RFT1 pathway f...Heading date is a critical trait that determines the regional adaptability and grain productivity of many crops.Although rice is a facultative short-day plant,its domestication led to the Ghd7-Ehd1-Hd3a/RFT1 pathway for adaptation to long-day conditions(LDs).The formation of the"florigen activation complex"(FAC)containing florigen Hd3a has been characterized.However,the molecular composition of the FAC that contains RFT1 for long-day flowering is unclear.We show here that RFT1 forms a ternary FAC with 14-3-3 proteins and OsFD1 to promote flowering under LDs.We identified a calcineurin B-like-interacting protein kinase,OsCIPK3,which directly interacts with and phosphorylates OsFD1,thereby facilitating the localization of the FAC to the nucleus.Mutation in OsCIPK3 results in a late heading date under LDs but a normal heading date under short-day conditions.Collectively,our results suggest that OsCIPK3 phosphorylates OsFD1 to promote RFT1-containing FAC formation and consequently induce flowering in rice under LDs.展开更多
Electrochemical nitrogen reduction reaction (eNRR) is an alternative promising manner for sustainable N2 fixation with low-emission. The major challenge for developing an efficient electrocatalyst is the cleaving of t...Electrochemical nitrogen reduction reaction (eNRR) is an alternative promising manner for sustainable N2 fixation with low-emission. The major challenge for developing an efficient electrocatalyst is the cleaving of the stable Ntriple bondN triple bonds. Herein, we design a new MoS_(2) with in-plane defect cluster through a bottom-up approach for the first time, where the defect cluster is composed of three adjacent S vacancies. The well-defined in-plane defect clusters could contribute to the strong chemical adsorption and activation towards inert nitrogen, achieving an excellent eNRR performance with an ammonia yield rate of 43.4 ± 3 μg h^(−1) mgcat.^(−1) and a Faradaic efficiency of 16.8 ± 2% at −0.3 V (vs. RHE). The performance is much higher than that of MoS_(2) with the edge defect. Isotopic labeling confirms that N atoms of produced NH4+ originate from N2. Furthermore, the in-plane defect clusters realized the alternate hydrogenation of nitrogen in a side-on way to synthesize ammonia. This work provides a prospecting strategy for fine-tuning in-plane defects in a catalyst, and also promotes the progress of eNRR.展开更多
The gear transmission system has been widely applied in mechanical systems, and many high-performance applications of these systems require low weight. With the aid of establishing the optimization model of the gear t...The gear transmission system has been widely applied in mechanical systems, and many high-performance applications of these systems require low weight. With the aid of establishing the optimization model of the gear transmission system that consists of an objective function and some constraints （for example, the bending stress, the contact stress, the torsional strength, etc.）, the optimal weight design of the gear transmission system can be transformed into the optimization problem for the objective function under the constraints. Moreover, both the shaft and the gear of the gear transmission system are considered simultaneously in our design. The hybrid Taguchi-genetic algorithm （HTGA） is employed to find the optimal design variables and the optimal weight of the system. An illustrated example for the single spur gear reducer is given to show that the optimal weight design problem can be successfully solved using the proposed design scheme. It also proves the high efficiency and feasibility of the algorithm in the gear design.展开更多
The activation of H_(2)O is a key step of the COS hydrolysis,which may be tuned by oxygen vacancy defects in the catalysts.Herein,we have introduced Cu into Co_(3)O_(4) to regulate the oxygen vacancy defect content of...The activation of H_(2)O is a key step of the COS hydrolysis,which may be tuned by oxygen vacancy defects in the catalysts.Herein,we have introduced Cu into Co_(3)O_(4) to regulate the oxygen vacancy defect content of the catalysts.In situ DRIFTS and XPS spectra reveal that COS and H_(2)O are adsorbed and activated by oxygen vacancy.The 10 at%Cu doped Co_(3)O_(4) sample(10Cu-Co_(3)O_(4))exhibits the optimal activity,100%of COS conversion at 70℃.The improved oxygen vacancies of CueCo_(3)O_(4) accelerate the activation of H_(2)O to form active -OH.COS binds with hydroxyl to form the intermediate HSCO^(-)_(2),and then the activated-OH on the oxygen vacancy reacts with HSCO^(-)_(2) to form HCO^(-)_(3).Meanwhile,the catalyst exhibits high catalytic stability because copper species(Cu+/Cu^(2+))redox cycle mitigate the sulfation of Co_(3)O_(4)(Co^(2+)/Co^(3+)).Our work offers a promising approach for the rational design of cobalt-related catalysts in the highly efficient hydrolysis COS process.展开更多
Bloody Mahjong is a kind of mahjong.It is very popular in China in recent years.It not only has the characteristics of mahjong's conventional state space,huge hidden information,complicated rules,and large randomn...Bloody Mahjong is a kind of mahjong.It is very popular in China in recent years.It not only has the characteristics of mahjong's conventional state space,huge hidden information,complicated rules,and large randomness of hand cards but also has special rules such as Change three,Hu must lack at least one suit,and Continue playing after Hu.These rules increase the difficulty of research.These special rules are used as the input of the deep learning DenseNet model.DenseNet is used to extract the Mahjong situation features.The learned features are used as the input of the classification algorithm XGBoost,and then the XGBoost algorithm is used to derive the card strategy.Experiments show that the fusion model of deep learning and XGBoost proposed in this paper has higher accuracy than the single model using only one of them in the case of highdimensional sparse features.In the case of fewer training rounds,accuracy of the model can still reach 83%.In the games against real people,it plays like human.展开更多
In order to analyze the influence of vortex-induced vibration on the strength and stability of marine drilling risers, a simplified analytical model was established and a method for calculating vortex-induced dynamic ...In order to analyze the influence of vortex-induced vibration on the strength and stability of marine drilling risers, a simplified analytical model was established and a method for calculating vortex-induced dynamic response was developed. A case study indicated that at primary resonance, first-order dynamic displacement response is greater than higher-order mode responses, but the influence of dynamic moment and shearing force of higher-order modes cannot be ignored. The natural fi＇equency of risers decreased sharply with increasing length of the riser, but increased with increasing top tension. Various factors should be considered to avoid vortex-induced vibration in practical application, and the influence of vortex-induced vibration could be estimated by calculating the fatigue lifetime of riser.展开更多
Surface chemistry focuses on the investigation of the adsorption,migration,assembly,activation,reaction,and desorption of atoms and molecules at surfaces.Surface chemistry plays the pivotal roles in both fundamental s...Surface chemistry focuses on the investigation of the adsorption,migration,assembly,activation,reaction,and desorption of atoms and molecules at surfaces.Surface chemistry plays the pivotal roles in both fundamental science and applied technology.This review will summarize the recent progresses on surface assembly,synthesis and catalysis investigated mainly by scanning tunneling microscopy and atomic force microscopy.Surface assemblies of water and small biomolecules,construction of Sierpin′ski triangles and surface chirality are summarized.On-surface synthesis of conjugated carbo-and heterocycles and other kinds of carbon nanostructures are surveyed.Surface model catalysis,including single-atom catalysis and electrochemical catalysis,are discussed at the single-atom level.展开更多
基金supported by a key project of the National Natural Science Foundation of China(No.81330090)the Chinese Medicine Antiviral Collaborative Innovation Center(No.XTCX2014B01-06)
文摘Although oxymatrine(OMT) has been shown to directly inhibit the replication of hepatitis B virus(HBV) in vitro, limited research has been done with this drug in vivo. In the present study, the antiviral effect of OMT was investigated in an immunocompetent mouse model of chronic HBV infection.The infection was achieved by tail vein injection of a large volume of DNA solution. OMT(2.2, 6.7 and20 mg/kg) was administered by daily intraperitoneal injection for 6 weeks. The efficacy of OMT was evaluated by the levels of HBV DNA, hepatitis B surface antigen(HBs Ag), hepatitis B e antigen(HBe Ag)and hepatitis B core antigen(HBc Ag). The immunoregulatory activity of OMT was evaluated by serum ELISA and flow cytometry. Results shows that OMT at 20 mg/kg inhibited HBV replication, and it was more efficient than entecavir(ETV) in the elimination of serum HBs Ag and intrahepatic HBc Ag. Inaddition, OMT accelerated the production of interferon-γ(IFN-γ) in a dose-dependent manner in CD4^+T cells. Our findings demonstrate the beneficial effects of OMT on the enhancement of immunological function and in the control of HBV antigens. The findings suggest this drug to be a good antiviral therapeutic candidate for the treatment of HBV infection.
文摘Background It remains almost a helpless situation for the recurrent implantation failure and pregnancy loss caused by endometrial injury at present. The purpose of this study was to develop a rabbit model of endometrial mechanical injury that could provide a research platform for this difficult clinical predicament. Methods Three experiments were conducted. Experiment 1： Curettages in both uterus horns and copper wire inserting after curettage （double-injury） in one horn. The histological changes were monitored at 0, 24, 48, 72 hours, as well as in 1 and 2 weeks after operation. Experiment 2： Direct copper wire inserting in one horn and double-injury in other horn. The wires in both horns were removed after 2 weeks.
基金This work was supported by a TOTAL SA research grant funded through MITei(supporting the experimental XRD),the National Research Foundation(NRF),Singapore through the Singapore Massachusetts Institute of Technology(MIT)Alliance for Research and Technology’s Low Energy Electronic Systems research program(supporting the machine learning algorithm development),the Accelerated Materials Development for Manufacturing Program at A*STAR via the AME Programmatic Fund by the Agency for Science,Technology and Research under Grant No.A1898b0043(for ML algorithm error analysis)by the U.S.Department of Energy under the Photovoltaic Research and Development program under Award DE-EE0007535(for code framework development)This work made use of the CMSE at MIT,which is supported by NSF award DMR-0819762.
文摘X-ray diffraction(XRD)data acquisition and analysis is among the most time-consuming steps in the development cycle of novel thin-film materials.We propose a machine learning-enabled approach to predict crystallographic dimensionality and space group from a limited number of thin-film XRD patterns.We overcome the scarce data problem intrinsic to novel materials development by coupling a supervised machine learning approach with a model-agnostic,physics-informed data augmentation strategy using simulated data from the Inorganic Crystal Structure Database(ICSD)and experimental data.As a test case,115 thin-film metalhalides spanning three dimensionalities and seven space groups are synthesized and classified.After testing various algorithms,we develop and implement an all convolutional neural network,with cross-validated accuracies for dimensionality and space group classification of 93 and 89%,respectively.We propose average class activation maps,computed from a global average pooling layer,to allow high model interpretability by human experimentalists,elucidating the root causes of misclassification.Finally,we systematically evaluate the maximum XRD pattern step size(data acquisition rate)before loss of predictive accuracy occurs,and determine it to be 0.16°2θ,which enables an XRD pattern to be obtained and classified in 5.5 min or less.
文摘Background The purpose of this retrospective study was to compare the surgical outcomes of simple discectomy and instrumented posterior lumbar interbody fusion （iPLIF） in patients with lumbar disc herniation and Modic endplate changes.Our hypothesis was that iPLIF could provide better outcome for patients with refractory lumbar disc herniation and Modic changes （LDH-MC）.Methods Ninety-one patients with single-segment LDH-MC were recruited.All patients experienced low back pain as well as radicular leg pain,and low back pain was more severe than leg pain.Forty-seven patients were treated with discectomy and 44 were treated with iPLIE The outcomes of both low back pain and radicular leg pain using visual analogue scale （VAS） as well as the clinical outcome related to low back pain using Japanese Orthopaedic Association （JOA） score were assessed before and 18 months after surgery,respectively.Results Both low back and leg pain were significantly improved 18 months after simple discectomy and iPLIE Compared to patients undergoing simple discectomy,low back pain was significantly reduced in patients undergoing iPLIE but there was no significant difference in leg pain between two groups.Solid fusion was achieved in all patients who underwent iPLIF.Conclusions In patients with LDH-MC,iPLIF can yield significantly superior outcome on the relief of low back pain compared to simple discectomy.Simple discectomy can relieve radicular leg pain as efficient as iPLIE Accordingly,iPLIF seems to be a reliable treatment for patients with LDH-MC and predominant low back pain.
基金Supported by National Natural Science Foundation of China(Grant No.51705372)National Science and Technology Project of the Power Grid of China(Grant No.5211DS16002L).
文摘According to statistic data,machinery faults contribute to largest proportion of High-voltage circuit breaker failures,and traditional maintenance methods exist some disadvantages for that issue.Therefore,based on the wavelet packet decomposition approach and support vector machines,a new diagnosis model is proposed for such fault diagnoses in this study.The vibration eigenvalue extraction is analyzed through wavelet packet decomposition,and a four-layer support vector machine is constituted as a fault classifier.The Gaussian radial basis function is employed as the kernel function for the classifier.The penalty parameter c and kernel parameterδof the support vector machine are vital for the diagnostic accuracy,and these parameters must be carefully predetermined.Thus,a particle swarm optimizationsupport vector machine model is developed in which the optimal parameters c andδfor the support vector machine in each layer are determined by the particle swarm algorithm.The validity of this fault diagnosis model is determined with a real dataset from the operation experiment.Moreover,comparative investigations of fault diagnosis experiments with a normal support vector machine and a particle swarm optimization back-propagation neural network are also implemented.The results indicate that the proposed fault diagnosis model yields better accuracy and e-ciency than these other models.
基金supported by the Natural Science Foundation of Jiangsu Province for Distinguished Young Scholars (No. BK20170038)the Natural Science Foundation of Jiangsu Province (No. BK20151485)the National Natural Science Foundation of China (Nos. 51478225 and 51778294)
文摘Simultaneous pyridine biodegradation and nitrogen removal were successfully achieved in a sequencing batch reactor（SBR） based on aerobic granules. In a typical SBR cycle, nitritation occurred obviously after the majority of pyridine was removed, while denitrification occurred at early stage of the cycle when oxygen consumption was aggravated. The effect of several key operation parameters, i.e., air flow rate, influent NH4~＋-N concentration,influent p H and pyridine concentration, on nitritation, pyridine degradation and total nitrogen（TN） removal, was systematically investigated. The results indicated that high air flow rate had a positive effect on both pyridine degradation and nitritation but a negative impact of overhigh air flow rate. With the increase of NH4~＋ dosage, both nitritation and TN removal could be severely inhibited. Slightly alkaline condition, i.e., pH 7.0–8.0, was beneficial for both pyridine degradation and nitritation. High pyridine dosage often resulted in the delay of both pyridine degradation and nitritation. Besides, extracellular polymeric substances production was affected by air flow rate, NH4~＋ dosage, pyridine dosage and p H.In addition, high-throughput sequencing analysis demonstrated that Bdellovibrio and Paracoccus were the dominant species in the aerobic granulation system. Coexistence of pyridine degrader, nitrification related species, denitrification related species, polymeric substances producer and self-aggregation related species was also confirmed by highthroughput sequencing.
基金This research was financially supported by the National Key R&D Program of China(2018YFD1000605)the Tianjin Science Fund for Distinguished Young Scholars(18JCJQJC48300).
文摘Zanthoxylum bungeanum is an important spice and medicinal plant that is unique for its accumulation of abundant secondary metabolites,which create a characteristic aroma and tingling sensation in the mouth.Owing to the high proportion of repetitive sequences,high heterozygosity,and increased chromosome number of Z.bungeanum,the assembly of its chromosomal pseudomolecules is extremely challenging.Here,we present a genome sequence for Z.bungeanum,with a dramatically expanded size of 4.23 Gb,assembled into 68 chromosomes.This genome is approximately tenfold larger than that of its close relative Citrus sinensis.After the divergence of Zanthoxylum and Citrus,the lineage-specific whole-genome duplication event q-WGD approximately 26.8 million years ago(MYA)and the recent transposable element(TE)burst~6.41 MYA account for the substantial genome expansion in Z.bungeanum.The independent Zanthoxylum-specific WGD event was followed by numerous fusion/fission events that shaped the genomic architecture.Integrative genomic and transcriptomic analyses suggested that prominent speciesspecific gene family expansions and changes in gene expression have shaped the biosynthesis of sanshools,terpenoids,and anthocyanins,which contribute to the special flavor and appearance of Z.bungeanum.In summary,the reference genome provides a valuable model for studying the impact of WGDs with recent TE activity on gene gain and loss and genome reconstruction and provides resources to accelerate Zanthoxylum improvement.
基金supported by the National Natural Science Foundation of China(11075113)
文摘Ni-Co bimetallic catalysts with different Ni/Co content were derived from cold plasma jet decomposition and reduction of hydrotalcite-like compounds containing Ni,Co,Mg and Al,and their catalytic performance was investigated with dry reforming of methane.Experimental results showed that the hydrotalcite-like precursors could be completely decomposed and partly reduced by cold plasma jet,and the Nicontained catalysts exhibited much higher activity than the catalyst without Ni.Especially,the catalyst with Ni/Co ratio of 8/2 achieved not only the highest conversions of 80.3%and 69.3%for CH4 and CO2,respectively,but also the best stability in 100 h testing.The catalysts were characterized by XRD,XPS,TEM and N2 adsorption techniques,and the results showed that the better performance of the 8Ni2Co bimetallic catalyst was attributed to its higher metal dispersion,smaller metal particle size,as well as the interaction effect between Ni and Co,which were brought by the special catalyst preparation method.
基金supported by the National Key R&D Program of China(2018YFD1000605)Biosafety and Genetic Resource Management Project(KJZXSA202025).
文摘Chinese pepper,mainly including Zanthoxylum bungeanum and Zanthoxylum armatum,is an economically important crop popular in Asian countries due to its unique taste characteristics and potential medical uses.Numerous cultivars of Chinese pepper have been developed in China through long-term domestication.To better understand the population structure,demographic history,and speciation of Chinese pepper,we performed a comprehensive analysis at a genome-wide level by analyzing 38,395 genomic SNPs that were identified in 112 cultivated and wild accessions using a high-throughput genomewide genotyping-by-sequencing(GBS)approach.Our analysis provides genetic evidence of multiple splitting events occurring between and within species,resulting in at least four clades in Z.bungeanum and two clades in Z.armatum.Despite no evidence of recent admixture between species,we detected substantial gene flow within species.Estimates of demographic dynamics and species distribution modeling suggest that climatic oscillations during the Pleistocene(including the Penultimate Glaciation and the Last Glacial Maximum)and recent domestication events together shaped the demography and evolution of Chinese pepper.Our analyses also suggest that southeastern Gansu province is the most likely origin of Z.bungeanum in China.These findings provide comprehensive insights into genetic diversity,population structure,demography,and adaptation in Zanthoxylum.
文摘Trachoma is one of the most widespread blinding eye diseases, which is harmful to human visual health. The efforts to prevent and control trachoma in China can be divided into three periods, i.e., highly epidemic period, research on pathogenesis and control of trachoma, and blinding trachoma elimination and epidemiological evaluation. In 1956, Prof. Feifan Tang and Xiaolou Zhang first discovered and isolated Chlamydia trachomatis, which clarified the cause of trachoma, and kick-started a fresh chapter in trachoma research, prevention, and control around the world. Although, the prevalence of trachoma differed in different areas, the average prevalence once exceeded 50% and was as high as 90% in some areas before and at early liberation of China. Therefore, the government-led efforts were made to comprehensively prevent and control trachoma, including development of National Plan for the Prevention and Control of Trachoma, nationwide screening and treatment of trachoma, implementation of National Patriotic Health Campaign and improvement of water supply and lavatories. After decades of effort, China reached the goal of eliminating blinding trachoma in 2015. China has gained remarkable achievements in the prevention and treatment of trachoma, making outstanding contributions toward the goal of eliminating trachoma worldwide. The research, prevention, and control of trachoma in China were reviewed in this paper.
基金the National Natural Science Foundation of China(31630054,32070855,31821005)the National Key Research and Development Program of China(2016YFD0100903)the Ministry of Agriculture Innovation Team Plan.
文摘Heading date is a critical trait that determines the regional adaptability and grain productivity of many crops.Although rice is a facultative short-day plant,its domestication led to the Ghd7-Ehd1-Hd3a/RFT1 pathway for adaptation to long-day conditions(LDs).The formation of the"florigen activation complex"(FAC)containing florigen Hd3a has been characterized.However,the molecular composition of the FAC that contains RFT1 for long-day flowering is unclear.We show here that RFT1 forms a ternary FAC with 14-3-3 proteins and OsFD1 to promote flowering under LDs.We identified a calcineurin B-like-interacting protein kinase,OsCIPK3,which directly interacts with and phosphorylates OsFD1,thereby facilitating the localization of the FAC to the nucleus.Mutation in OsCIPK3 results in a late heading date under LDs but a normal heading date under short-day conditions.Collectively,our results suggest that OsCIPK3 phosphorylates OsFD1 to promote RFT1-containing FAC formation and consequently induce flowering in rice under LDs.
基金This work was supported by the National Natural Science Foundation of China(22078063,21825801).
文摘Electrochemical nitrogen reduction reaction (eNRR) is an alternative promising manner for sustainable N2 fixation with low-emission. The major challenge for developing an efficient electrocatalyst is the cleaving of the stable Ntriple bondN triple bonds. Herein, we design a new MoS_(2) with in-plane defect cluster through a bottom-up approach for the first time, where the defect cluster is composed of three adjacent S vacancies. The well-defined in-plane defect clusters could contribute to the strong chemical adsorption and activation towards inert nitrogen, achieving an excellent eNRR performance with an ammonia yield rate of 43.4 ± 3 μg h^(−1) mgcat.^(−1) and a Faradaic efficiency of 16.8 ± 2% at −0.3 V (vs. RHE). The performance is much higher than that of MoS_(2) with the edge defect. Isotopic labeling confirms that N atoms of produced NH4+ originate from N2. Furthermore, the in-plane defect clusters realized the alternate hydrogenation of nitrogen in a side-on way to synthesize ammonia. This work provides a prospecting strategy for fine-tuning in-plane defects in a catalyst, and also promotes the progress of eNRR.
基金Supported by the Fundamental Research Funds for the Central Universities (20102080201000085)the National Natural Science Foundation of China (50875189)
文摘The gear transmission system has been widely applied in mechanical systems, and many high-performance applications of these systems require low weight. With the aid of establishing the optimization model of the gear transmission system that consists of an objective function and some constraints （for example, the bending stress, the contact stress, the torsional strength, etc.）, the optimal weight design of the gear transmission system can be transformed into the optimization problem for the objective function under the constraints. Moreover, both the shaft and the gear of the gear transmission system are considered simultaneously in our design. The hybrid Taguchi-genetic algorithm （HTGA） is employed to find the optimal design variables and the optimal weight of the system. An illustrated example for the single spur gear reducer is given to show that the optimal weight design problem can be successfully solved using the proposed design scheme. It also proves the high efficiency and feasibility of the algorithm in the gear design.
基金the National Natural Science Foundation of China (92034301,22078063 and 22022804)Major Program of Qingyuan Innovation Laboratory (00121003)the Natural Science Foundation of Fujian Province (2020H6007)。
文摘The activation of H_(2)O is a key step of the COS hydrolysis,which may be tuned by oxygen vacancy defects in the catalysts.Herein,we have introduced Cu into Co_(3)O_(4) to regulate the oxygen vacancy defect content of the catalysts.In situ DRIFTS and XPS spectra reveal that COS and H_(2)O are adsorbed and activated by oxygen vacancy.The 10 at%Cu doped Co_(3)O_(4) sample(10Cu-Co_(3)O_(4))exhibits the optimal activity,100%of COS conversion at 70℃.The improved oxygen vacancies of CueCo_(3)O_(4) accelerate the activation of H_(2)O to form active -OH.COS binds with hydroxyl to form the intermediate HSCO^(-)_(2),and then the activated-OH on the oxygen vacancy reacts with HSCO^(-)_(2) to form HCO^(-)_(3).Meanwhile,the catalyst exhibits high catalytic stability because copper species(Cu+/Cu^(2+))redox cycle mitigate the sulfation of Co_(3)O_(4)(Co^(2+)/Co^(3+)).Our work offers a promising approach for the rational design of cobalt-related catalysts in the highly efficient hydrolysis COS process.
基金Promoting Research Level Program,Beijing Information Science and Technology University,Grant/Award Number:5211910927General Science and Technology Research program,Grant/Award Number:KM201911232002Graduated Education Program at Beijing Information Science and Technology University。
文摘Bloody Mahjong is a kind of mahjong.It is very popular in China in recent years.It not only has the characteristics of mahjong's conventional state space,huge hidden information,complicated rules,and large randomness of hand cards but also has special rules such as Change three,Hu must lack at least one suit,and Continue playing after Hu.These rules increase the difficulty of research.These special rules are used as the input of the deep learning DenseNet model.DenseNet is used to extract the Mahjong situation features.The learned features are used as the input of the classification algorithm XGBoost,and then the XGBoost algorithm is used to derive the card strategy.Experiments show that the fusion model of deep learning and XGBoost proposed in this paper has higher accuracy than the single model using only one of them in the case of highdimensional sparse features.In the case of fewer training rounds,accuracy of the model can still reach 83%.In the games against real people,it plays like human.
文摘In order to analyze the influence of vortex-induced vibration on the strength and stability of marine drilling risers, a simplified analytical model was established and a method for calculating vortex-induced dynamic response was developed. A case study indicated that at primary resonance, first-order dynamic displacement response is greater than higher-order mode responses, but the influence of dynamic moment and shearing force of higher-order modes cannot be ignored. The natural fi＇equency of risers decreased sharply with increasing length of the riser, but increased with increasing top tension. Various factors should be considered to avoid vortex-induced vibration in practical application, and the influence of vortex-induced vibration could be estimated by calculating the fatigue lifetime of riser.
基金supported by the National Natural Science Foundation of China(Nos.22225202,92356309,22132007,21991132,22172002)。
文摘Surface chemistry focuses on the investigation of the adsorption,migration,assembly,activation,reaction,and desorption of atoms and molecules at surfaces.Surface chemistry plays the pivotal roles in both fundamental science and applied technology.This review will summarize the recent progresses on surface assembly,synthesis and catalysis investigated mainly by scanning tunneling microscopy and atomic force microscopy.Surface assemblies of water and small biomolecules,construction of Sierpin′ski triangles and surface chirality are summarized.On-surface synthesis of conjugated carbo-and heterocycles and other kinds of carbon nanostructures are surveyed.Surface model catalysis,including single-atom catalysis and electrochemical catalysis,are discussed at the single-atom level.
