Ex situ characterization techniques in molecular beam epitaxy(MBE)have inherent limitations,such as being prone to sample contamination and unstable surfaces during sample transfer from the MBE chamber.In recent years...Ex situ characterization techniques in molecular beam epitaxy(MBE)have inherent limitations,such as being prone to sample contamination and unstable surfaces during sample transfer from the MBE chamber.In recent years,the need for improved accuracy and reliability in measurement has driven the increasing adoption of in situ characterization techniques.These techniques,such as reflection high-energy electron diffraction,scanning tunneling microscopy,and X-ray photoelectron spectroscopy,allow direct observation of film growth processes in real time without exposing the sample to air,hence offering insights into the growth mechanisms of epitaxial films with controlled properties.By combining multiple in situ characterization techniques with MBE,researchers can better understand film growth processes,realizing novel materials with customized properties and extensive applications.This review aims to overview the benefits and achievements of in situ characterization techniques in MBE and their applications for material science research.In addition,through further analysis of these techniques regarding their challenges and potential solutions,particularly highlighting the assistance of machine learning to correlate in situ characterization with other material information,we hope to provide a guideline for future efforts in the development of novel monitoring and control schemes for MBE growth processes with improved material properties.展开更多
The coherent muon-to-electron transition(COMET)experiment is a leading experiment for the coherent conversion of μ^(-)N→e^(-)N using a high-intensity pulsed muon beamline,produced using innovative slow-extraction te...The coherent muon-to-electron transition(COMET)experiment is a leading experiment for the coherent conversion of μ^(-)N→e^(-)N using a high-intensity pulsed muon beamline,produced using innovative slow-extraction techniques.Therefore,it is critical to measure the muon beam characteristics.We set up a muon beam monitor(MBM),where scintillating fibers woven in a cross shape were coupled to silicon photomultipliers to measure the spatial profile and timing structure of the extracted muon beam for the COMET.The MBM detector was tested successfully with a proton beamline at the China Spallation Neutron Source and took data with good performance in the commissioning run.The development of the MBM,including its mechanical structure,electronic readout,and beam measurement results,are discussed.展开更多
Background:The specific impact of sphingolipid metabolism on developing hepatocellular Carcinoma(HCC)remains unclear.This study aims to explore the relationship between sphingolipid metabolism and HCC prognosis,immune ...Background:The specific impact of sphingolipid metabolism on developing hepatocellular Carcinoma(HCC)remains unclear.This study aims to explore the relationship between sphingolipid metabolism and HCC prognosis,immune response,and drug sensitivity.Methods:Data were obtained from The Cancer Genome Atlas(TCGA)-Hepatocellular Carcinoma(LIHC)and Gene Expression Omnibus(GEO,GSE14520 datasets).47 sphingolipid metabolism genes were obtained from the Kyoto Encyclopedia of Genes and Genomes(KEGG)database.After classifying HCC samples using the Non-negative Matrix Factorization(NMF)clustering method,differentially expressed genes were screened.Then,8 risk genes were obtained by univariate analysis,survival random forest reduction and lasso analysis.The expression of 8 risk genes was verified in vitro.Results:8 risk genes were used to construct the Sphingolipid score model.High-Sphingolipid score predicted poor prognosis of HCC patients.Sphingolipid score was associated with immune checkpoints(IL-1B,TLR4,TGFB1,and IL-10),immune cells(Th2,Treg,MDSC,Neutrophil,Fibroblasts and macrophage),and MAPK Cascade.In the High-Sphingolipid score group,a significantly higher proportion of patients with TP53(p53)mutations was significantly higher(56%).Furthermore,patients with a high-Sphingolipid score were predicted to have a higher sensitivity to chemotherapy drugs.In vitro validation showed that compared with normal liver cells LX-2,TRIM47,and S100A9 significantly increased in liver cancer cells Hep G2,MHCC-97H,and Hep3B2.1-7,while SLC1A7,LPCAT1,and CFHR4 significantly decreased.Silencing TRIM47 reduced the proliferation and promoted apoptosis.The levels of ceramide synthesis-related indexes(CERS1,CERS6,CERS5,and SPTLC2)increased,and the ACER3 related to catalytic hydrolysis decreased.Conclusion:We constructed a sphingolipid metabolism-related prognostic signature(Sphingolipid score)based on 8 risk genes.TRIM47 may affect the development of liver cancer by regulating the relevant indicators of ceramide synthesis and catalytic hydrolysis.展开更多
With the rapid development of modern agriculture,the prevention and control of crop diseases and insect pests has become an important part to ensure the safety of agricultural production,the quality of agricultural pr...With the rapid development of modern agriculture,the prevention and control of crop diseases and insect pests has become an important part to ensure the safety of agricultural production,the quality of agricultural products and the safety of agricultural ecological environment.Although the effect of traditional chemical prevention and control technology is remarkable,the health risks and environmental problems brought by it should not be ignored.As a green and environmentally friendly means of prevention and control,biological prevention and control technology has gradually become a hot research topic and a trend of agricultural production.This paper is intended to comprehensively evaluate the social costs of biological control technologies for crop diseases and pests,including the health risks reduced,environmental improvements,economic benefits,and barriers to promotion,and put forward corresponding policy recommendations.展开更多
In the field of biological control of agricultural and forestry pests,natural enemy insects play an important role,constituting the core of modern integrated pest management(IPM)strategy,providing solid support for th...In the field of biological control of agricultural and forestry pests,natural enemy insects play an important role,constituting the core of modern integrated pest management(IPM)strategy,providing solid support for the zero growth goal of chemical pesticide use,and helping the sustainable development of green agriculture.The rise of the natural enemy insect industry has become a key driver of the transformation of green agriculture,injecting vitality into the sustainability and ecological protection of agriculture.With the increasing concern about food safety,environmental protection and ecological balance all over the world,the application scope of natural enemy insects as biological control means is constantly expanding.Its unique ecological adaptability and environmentally friendly characteristics help to reduce dependence on chemical pesticides,ensure the safety of agricultural products and maintain ecological diversity.The purpose of this study is to analyze the current situation of natural enemy insect industry,evaluate its cost and benefit,emphasize its great significance in promoting the transformation of green agriculture,improving production efficiency and promoting ecological protection by drawing lessons from foreign successful experiences,and explore an efficient and sustainable new agricultural development model.展开更多
Air pollution control poses a major problem in the implementation of municipal solid waste incineration(MSWI).Accurate prediction of nitrogen oxides(NO_(x))concentration plays an important role in efficient NO_(x)emis...Air pollution control poses a major problem in the implementation of municipal solid waste incineration(MSWI).Accurate prediction of nitrogen oxides(NO_(x))concentration plays an important role in efficient NO_(x)emission controlling.In this study,a modular long short-term memory(M-LSTM)network is developed to design an efficient prediction model for NO_(x)concentration.First,the fuzzy C means(FCM)algorithm is utilized to divide the task into several sub-tasks,aiming to realize the divide-and-conquer ability for complex task.Second,long short-term memory(LSTM)neural networks are applied to tackle corresponding sub-tasks,which can improve the prediction accuracy of the sub-networks.Third,a cooperative decision strategy is designed to guarantee the generalization performance during the testing or application stage.Finally,after being evaluated by a benchmark simulation,the proposed method is applied to a real MSWI process.And the experimental results demonstrate the considerable prediction ability of the M-LSTM network.展开更多
Starting from the effects of diseases and pests on tea quality,tea industry and export trade,the status quo and control of tea diseases and pests,assurance and traceability of tea quality safety,tea industry and expor...Starting from the effects of diseases and pests on tea quality,tea industry and export trade,the status quo and control of tea diseases and pests,assurance and traceability of tea quality safety,tea industry and export trade development are analyzed in detail,and green prevention and control measures against tea diseases and pests are put forward combined with the status quo of tea in China.展开更多
Soil information is the basis of soil management and precise variable fertilization. The traditional method of obtaining soil information through chemical detection of laboratory has high cost and poor timeliness, whi...Soil information is the basis of soil management and precise variable fertilization. The traditional method of obtaining soil information through chemical detection of laboratory has high cost and poor timeliness, which is difficult to meet the needs of digital forestry, soil monitoring and real-time management of nutrients. Taking red soil of Eucalyptus plantation in northern Guangxi as the research object, the spectral data of samples with different soil available potassium contents were measured, and the spectral characteristics were analyzed, and the inversion model was established by using PLS method. The results showed that the spectral sensitive bands of available potassium content in red soil of the region mainly concentrated in 400-600, 1 450, 2 200 nm and so on. After the first derivative transformation, the redundant information in the original spectral data can be significantly reduced, and the correlation between spectral indexes and soil available potassium content can be improved. The full-band modeling results of R and FDR were better than those of significant bands. The optimal model was full-band-FDR-PLS, R2=0.862, and RMSE=2.718. The results of this study can be used for the application of near-earth remote sensing in Guangxi, such as soil digital mapping, precise variable fertilization and real-time monitoring of soil available potassium.展开更多
As a traditional advantageous industry in Guizhou and an important export product,tea plays an important role in the rural revitalization strategy.This paper first introduces the current situation of tea industry and ...As a traditional advantageous industry in Guizhou and an important export product,tea plays an important role in the rural revitalization strategy.This paper first introduces the current situation of tea industry and export in Guizhou,then analyzes the problems that arise in the export process,and finally comes up with corresponding countermeasures and recommendations for the export development of tea,hoping to provide certain guidance and reference to the development of tea industry in Guizhou Province.展开更多
Hydraulic systems have the characteristics of strong fault concealment,powerful nonlinear time-varying signals,and a complex vibration transmission mechanism;hence,diagnosis of these systems is a challenge.To provide ...Hydraulic systems have the characteristics of strong fault concealment,powerful nonlinear time-varying signals,and a complex vibration transmission mechanism;hence,diagnosis of these systems is a challenge.To provide accurate diagnosis results automatically,numerous studies have been carried out.Among them,signal-based methods are commonly used,which employ signal processing techniques based on the state signal used for extracting features,and further input the features into the classifier for fault recognition.However,their main deficiencies include the following:(1)The features are manually designed and thus may have a lack of objectivity.(2)For signal processing,feature extraction and pattern recognition are conducted using independent models,which cannot be jointly optimized globally.(3)The machine learning algorithms adopted by these methods have a shallow architecture,which limits their capacity to deeply mine the essential features of a fault.As a breakthrough in artificial intelligence,deep learning holds the potential to overcome such deficiencies.Based on deep learning,deep neural networks(DNNs)can automatically learn the complex nonlinear relations implied in a signal,can be globally optimized,and can obtain the high-level features of multi-dimensional data.In this paper,the main technology used in an intelligent fault diagnosis and the current research status of hydraulic system fault diagnosis are summarized and analyzed.The significant prospect of applying deep learning in the field of intelligent fault diagnosis is presented,and the main ideas,methods,and principles of several typical DNNs are described and summarized.The commonality between a fault diagnosis and other issues regarding typical pattern recognition are analyzed,and research ideas for applying DNNs for hydraulic fault diagnosis are proposed.Meanwhile,the research advantages and development trend of DNNs(both domestically and overseas)as applied to an intelligent fault diagnosis are reviewed.Furthermore,the fault characteristics of a complex hydraulic system are summarized and discussed,and the key problems and possible research ideas of applying DNNs to an intelligent hydraulic fault diagnosis are presented and comprehensively analyzed.展开更多
Numerous studies have shown that topical application of mitomycin C after surgical decompression effectively reduces scar adhesion. However, the underlying mechanisms remain unclear. In this study, we investigated the...Numerous studies have shown that topical application of mitomycin C after surgical decompression effectively reduces scar adhesion. However, the underlying mechanisms remain unclear. In this study, we investigated the effect of mitomycin C on the proliferation and apoptosis of human epidural scar fibroblasts. Human epidural scar fibroblasts were treated with various concentrations of mitomycin C （1, 5, 10, 20, 40 μg/mL） for 12, 24 and 48 hours. Mitomycin C suppressed the growth of these cells in a dose- and time-dependent manner. Mitomycin C upregulated the expression levels of Fas, DR4, DR5, cleaved caspase-8/9, Bax, Bim and cleaved caspase-3 proteins, and it downregulated Bcl-2 and Bcl-xL expression. In addition, inhibitors of caspase-8 and caspase-9 （Z-IETD-FMK and Z-LEHD-FMK, respectively） did not fully inhibit mitomycin C-induced apoptosis. Furthermore, mitomycin C induced endoplasmic reticulum stress by increasing the expression of glucose-regulated protein 78, CAAT/enhancer-binding protein homologous protein （CHOP） and caspase 4 in a dose-dependent manner. Salubrinal significantly inhibited the mitomycin C-induced cell viability loss and apoptosis, and these effects were accompanied by a reduction in CHOP expression. Our results support the hypothesis that mitomycin C induces human epidural scar fibroblast apoptosis, at least in part, via the endoplasmic reticulum stress pathway.展开更多
The outcomes of hepatitis B virus(HBV) infection are closely related to the age at which infection was acquired. Infection acquired in adult life tends to be selflimited, in contrast to perinatal acquirement, for whic...The outcomes of hepatitis B virus(HBV) infection are closely related to the age at which infection was acquired. Infection acquired in adult life tends to be selflimited, in contrast to perinatal acquirement, for which chronic persistence of the HBV is a general outcome. Innate immunity plays an indispensable role in early virus infection, facilitating virus clearance. However, it has been reported that HBV is under-recognized and poorly eliminated by the innate immune system in the early stages of infection, possibly explaining the long-lasting persistence of viremia afterwards. Furthermore, due to the existence of covalently closed circular DNA, chronic HBV clearance is very difficult, even when patients are given interferon-α and nucleotide/nucleoside analogs for antiviral therapy. The mechanism by which HBV evades innate immune recognition and establishes persistent infection remains a subject of debate. Besides, some researchers are becoming more interested in how to eradicate chronic HBV infection by restoring or boosting innate immunity. This review aimed to summarize the current knowledge on how intrahepatocyte signaling pathways and innate immune cells act after the onset of HBV infection and how these actions are related to the persistence of HBV. We anticipate the insights presented herein to be helpful for future development of novel immune therapeutic strategies to fight HBV infection.展开更多
BACKGROUND The value of conventional magnetic resonance imaging in the differential diagnosis of thyroid nodules is limited;however,the value of multi-parameter diffusion-weighted imaging(DWI)in the quantitative evalu...BACKGROUND The value of conventional magnetic resonance imaging in the differential diagnosis of thyroid nodules is limited;however,the value of multi-parameter diffusion-weighted imaging(DWI)in the quantitative evaluation of thyroid nodules has not been well determined.AIM To determine the utility of multi-parametric DWI including mono-exponential,biexponential,stretched exponential,and kurtosis models for the differentiation of thyroid lesions.METHODS Seventy-nine patients(62 with benign and 17 with malignant nodules)underwent multi-b value diffusion-weighted imaging of the thyroid.Multiple DWI parameters were obtained for statistical analysis.RESULTS Good agreement was found for diffusion parameters of thyroid nodules.Malignant lesions displayed lower diffusion parameters including apparent diffusion coefficient(ADC),the true diffusion coefficient(D),the perfusion fraction(f),the distributed diffusion coefficient(DDC),the intravoxel water diffusion heterogeneity(α)and kurtosis model-derived ADC(Dapp),and higher apparent diffusional kurtosis(Kapp)than benign entities(all P<0.01),except for the pseudodiffusion coefficient(D*)(P>0.05).The area under the ROC curve(AUC)of the ADC(0 and 1000)was not significantly different from that of the ADC(0 and 2000),ADC(0 to 2000),ADC(0 to 1000),D,DDC,Dapp and Kapp(all P>0.05),but was significantly higher than the AUC of D*,f andα(all P<0.05)for differentiating benign from malignant lesions.CONCLUSION Multiple DWI parameters including ADC,D,f,DDC,α,Dapp and Kapp could discriminate benign and malignant thyroid nodules.The metrics including D,DDC,Dapp and Kapp provide additional information with similar diagnostic performance of ADC,combination of these metrics may contribute to differentiate benign and malignant thyroid nodules.The ADC calculated with higher b values may not lead to improved diagnostic performance.展开更多
AIM： To explore the existence and distribution of prohibitin （PHB） in nuclear matrix and its co-localization with products of some related genes during the differentiation of human hepatocarcinoma SNMC-7721 cells. ...AIM： To explore the existence and distribution of prohibitin （PHB） in nuclear matrix and its co-localization with products of some related genes during the differentiation of human hepatocarcinoma SNMC-7721 cells. METHODS： The nuclear matrix of the SMMC-7721 cells cultured with or without 5 × 10^-3 mmol/L hexamethylene bisacetamide （HNBA） was selectively extracted. Western blot was used to analyze the expression of PHB in nuclear matrix; immunofluorescence microscope observation was used to analyze the distribution of PHB in cell. LCSM was used to observe the co-localization of PHB with products of oncogenes and tumor suppressor genes. RESULTS： Western blot analysis showed that PHB existed in the composition of nuclear matrix proteins and was down-regulated by HMBA treatment. Immunofluorescence observation revealed that PHB existed in the nuclear matrix, and its distribution regions and expression levels were altered after HMBA treatment. Laser scanning confocal microscopy revealed the co-localization between PHB and the products of oncogenes or tumor repression genes including c-los, c-myc, p53 and Rb and its alteration of distributive area in the cells treated by HMBA. CONCLUSION： These data confirm that PHB is a nuclear matrix protein, which is located in the nuclear matrix, and the distribution and expression of PHB and its relation with associated genes may play significant roles during the differentiation of SMMC-7721 cells.展开更多
AIM： To investigate the association between the configurational and compositional changes of nuclear matrix and the differentiation of carcinoma cells. METHODS： Cells cultured with or without 5 × 10^-3 mmol/L o...AIM： To investigate the association between the configurational and compositional changes of nuclear matrix and the differentiation of carcinoma cells. METHODS： Cells cultured with or without 5 × 10^-3 mmol/L of hexamethylene bisacetamide （HMBA） on Nickel grids were treated by selective extraction and prepared for whole mount observation under electron microscopy. The samples were examined under transmission electron microscope. Nuclear matrix proteins were selectively extracted and subjected to subcellular proteomics study. The protein expression patterns were analyzed by PDQuest software. Spots of differentially expressed nuclear matrix proteins were excised and subjected to in situ digestion with trypsin. The peptides were analyzed by matrix-assisted laser- desorption/ionization time of flight mass spectrometry （MALDI-TOF-MS）. Data were submitted for database searching using Mascot tool （www.matrixscience.com）. RESULTS： The nuclear matrix （NM） and intermediate filament （IF） in SMMC-7721 hepatocarcinoma cells were found relatively sparse and arranged irregularly. The nuclear lamina was non-uniform, and two kinds of filaments were not tightly connected. After induction for differentiation by HMBA, the NM-IF filaments were concentrated and distributed uniformly. The heterogeneous population of filaments, including highly branched utrathin filaments could also be seen in the regular meshwork. The connection between the two kinds of filaments and the relatively thin, condensed and sharply demarcated lamina composed of intermediate- sized filaments was relatively fastened. Meanwhile, 21 NM proteins changed remarkably during SMMC-7721 cell differentiation. Four proteins, i.e. mutant Pystl, hypothetical protein, nucleophosminl, and LBP were downregulated, whereas four other proteins, eIF6, p44 subunit, 13-tubulin, and SIN3B were upregulated with the last one, SR2/ASF found only in the differentiated SMMC-7721 cells. CONCLUSION： The induced differentiation of SMMC-7721 cells by HMBA is accompanied by the configurational changes of nuclear matrix-intermediate filament （NM-IF） system and the compositional changes of nuclear matrix protein expression. These changes may be important morphological or functional indications of the cancer cell reversion.展开更多
The Ni−MoO_(2) heterostructure was synthesized in suit on porous bulk NiMo alloy by a facile powder metallurgy and hydrothermal method.The results of field emission scanning electron microscopy(SEM),field emission tra...The Ni−MoO_(2) heterostructure was synthesized in suit on porous bulk NiMo alloy by a facile powder metallurgy and hydrothermal method.The results of field emission scanning electron microscopy(SEM),field emission transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS)reveal that the as-prepared electrode possesses the heterostructure and a layer of Ni(OH)_(2) nanosheets is formed on the surface of Ni−MoO_(2) electrode simultaneously after hydrothermal treatment,which provides abundant interface and much active sites,as well as much active specific surface area.The results of hydrogen evolution reaction indicate that the Ni−MoO_(2) heterostructure electrode exhibits excellent catalytic performance,requiring only 41 mV overpotential to reach the current density of 10 mA/cm^(2).It also possesses a small Tafel slope of 52.7 mV/dec and long-term stability of electrolysis in alkaline medium.展开更多
A modulator is an essential building block in the integrated photonics,connecting the electrical with optical signals.The microring modulator gains much attention because of the small footprint,low drive voltage and h...A modulator is an essential building block in the integrated photonics,connecting the electrical with optical signals.The microring modulator gains much attention because of the small footprint,low drive voltage and high extinction ratio.An ultra-low V_(pp)and high-modulation-depth indium phosphide-based racetrack microring modulator is demonstrated in this paper.The proposed device mainly comprises one racetrack microring,incorporating a semiconductor amplifier,and coupling with a bus waveguide through a multimode interference coupler.Traveling wave electrodes are employed to supply bidirectional bias ports,terminating with a 50-Ω impedance.The on/off extinction ratio of the microring reaches 43.3 dB due to the delicately tuning of the gain.An 11 mV V_(pp),a maximum 42.5 dB modulation depth and a 6.6 GHz bandwidth are realized,respectively.This proposed microring modulator could enrich the functionalities and designability of the fundamental integrated devices.展开更多
The joint source scanning algorithm(SSA)scans locations and focal mechanisms of microseismic events simultaneously.Compared to the traditional source scanning algorithm,it yields much more events with extra informatio...The joint source scanning algorithm(SSA)scans locations and focal mechanisms of microseismic events simultaneously.Compared to the traditional source scanning algorithm,it yields much more events with extra information of focal mechanisms.The availability of more events and focal mechanisms make it possible to invert for a 2D gridded stress field.As a byproduct of hydrofracturing monitoring,the method offers a new way to extract stress field as a substitute to other more expensive technologies.This method is applied to a hydraulic fracturing dataset collected from one shale gas production field in the southeast of the Sichuan basin.A damped stress inversion is conducted to obtain a 2D stress field.five hydraulic-fracturing induced fractures can be determined from the result.The events associated with these fractures generally have relatively low stacked energy and are limited to the depth of horizontal well.One existing fault(possibly associated with the axis of the central Sichuan uplift)is also determined and the events associated with the existing fault generally have higher stacked energy and are more densely populated.The existing fault may also serve as a structural boundary where the rocks to the NW side are easier to be fractured while events on the other side are sparse with low stacked energy.The existing fault also divides the stress field into two regimes:the maximum compressional stress field to the NW and SE of the fault line are dominantly in NW-SE and N-S directions,respectively.展开更多
基金supported by the National Key R&D Program of China(Grant No.2021YFB2206503)National Natural Science Foundation of China(Grant No.62274159)+1 种基金CAS Project for Young Scientists in Basic Research(Grant No.YSBR-056)the“Strategic Priority Research Program”of the Chinese Academy of Sciences(Grant No.XDB43010102).
文摘Ex situ characterization techniques in molecular beam epitaxy(MBE)have inherent limitations,such as being prone to sample contamination and unstable surfaces during sample transfer from the MBE chamber.In recent years,the need for improved accuracy and reliability in measurement has driven the increasing adoption of in situ characterization techniques.These techniques,such as reflection high-energy electron diffraction,scanning tunneling microscopy,and X-ray photoelectron spectroscopy,allow direct observation of film growth processes in real time without exposing the sample to air,hence offering insights into the growth mechanisms of epitaxial films with controlled properties.By combining multiple in situ characterization techniques with MBE,researchers can better understand film growth processes,realizing novel materials with customized properties and extensive applications.This review aims to overview the benefits and achievements of in situ characterization techniques in MBE and their applications for material science research.In addition,through further analysis of these techniques regarding their challenges and potential solutions,particularly highlighting the assistance of machine learning to correlate in situ characterization with other material information,we hope to provide a guideline for future efforts in the development of novel monitoring and control schemes for MBE growth processes with improved material properties.
基金supported in part by Fundamental Research Funds for the Central Universities(23xkjc017)at Sun Yat-sen Universitythe National Natural Science Foundation of China(No.12075326)JSPS KAKENHI(No.22H00139)。
文摘The coherent muon-to-electron transition(COMET)experiment is a leading experiment for the coherent conversion of μ^(-)N→e^(-)N using a high-intensity pulsed muon beamline,produced using innovative slow-extraction techniques.Therefore,it is critical to measure the muon beam characteristics.We set up a muon beam monitor(MBM),where scintillating fibers woven in a cross shape were coupled to silicon photomultipliers to measure the spatial profile and timing structure of the extracted muon beam for the COMET.The MBM detector was tested successfully with a proton beamline at the China Spallation Neutron Source and took data with good performance in the commissioning run.The development of the MBM,including its mechanical structure,electronic readout,and beam measurement results,are discussed.
基金The work was supported by funds from The Science and Technology Project of Hangzhou City(Agriculture and Social Development,No.2016007)&(Agriculture and Social Development,No.20201231Y131)&(Social Development,No.20140633B57)The Science and Technology Project of Yuhang District,Hangzhou City(Nos.2017002&2014003)+2 种基金The Health Science and Technology Project of Hangzhou City(No.2015B32)Zhejiang Provincial Natural Science Foundation of China under Grant(No.LTGY23H160006)The Health Science and Technology Project of Zhejiang Province(No.2023XY009).
文摘Background:The specific impact of sphingolipid metabolism on developing hepatocellular Carcinoma(HCC)remains unclear.This study aims to explore the relationship between sphingolipid metabolism and HCC prognosis,immune response,and drug sensitivity.Methods:Data were obtained from The Cancer Genome Atlas(TCGA)-Hepatocellular Carcinoma(LIHC)and Gene Expression Omnibus(GEO,GSE14520 datasets).47 sphingolipid metabolism genes were obtained from the Kyoto Encyclopedia of Genes and Genomes(KEGG)database.After classifying HCC samples using the Non-negative Matrix Factorization(NMF)clustering method,differentially expressed genes were screened.Then,8 risk genes were obtained by univariate analysis,survival random forest reduction and lasso analysis.The expression of 8 risk genes was verified in vitro.Results:8 risk genes were used to construct the Sphingolipid score model.High-Sphingolipid score predicted poor prognosis of HCC patients.Sphingolipid score was associated with immune checkpoints(IL-1B,TLR4,TGFB1,and IL-10),immune cells(Th2,Treg,MDSC,Neutrophil,Fibroblasts and macrophage),and MAPK Cascade.In the High-Sphingolipid score group,a significantly higher proportion of patients with TP53(p53)mutations was significantly higher(56%).Furthermore,patients with a high-Sphingolipid score were predicted to have a higher sensitivity to chemotherapy drugs.In vitro validation showed that compared with normal liver cells LX-2,TRIM47,and S100A9 significantly increased in liver cancer cells Hep G2,MHCC-97H,and Hep3B2.1-7,while SLC1A7,LPCAT1,and CFHR4 significantly decreased.Silencing TRIM47 reduced the proliferation and promoted apoptosis.The levels of ceramide synthesis-related indexes(CERS1,CERS6,CERS5,and SPTLC2)increased,and the ACER3 related to catalytic hydrolysis decreased.Conclusion:We constructed a sphingolipid metabolism-related prognostic signature(Sphingolipid score)based on 8 risk genes.TRIM47 may affect the development of liver cancer by regulating the relevant indicators of ceramide synthesis and catalytic hydrolysis.
文摘With the rapid development of modern agriculture,the prevention and control of crop diseases and insect pests has become an important part to ensure the safety of agricultural production,the quality of agricultural products and the safety of agricultural ecological environment.Although the effect of traditional chemical prevention and control technology is remarkable,the health risks and environmental problems brought by it should not be ignored.As a green and environmentally friendly means of prevention and control,biological prevention and control technology has gradually become a hot research topic and a trend of agricultural production.This paper is intended to comprehensively evaluate the social costs of biological control technologies for crop diseases and pests,including the health risks reduced,environmental improvements,economic benefits,and barriers to promotion,and put forward corresponding policy recommendations.
文摘In the field of biological control of agricultural and forestry pests,natural enemy insects play an important role,constituting the core of modern integrated pest management(IPM)strategy,providing solid support for the zero growth goal of chemical pesticide use,and helping the sustainable development of green agriculture.The rise of the natural enemy insect industry has become a key driver of the transformation of green agriculture,injecting vitality into the sustainability and ecological protection of agriculture.With the increasing concern about food safety,environmental protection and ecological balance all over the world,the application scope of natural enemy insects as biological control means is constantly expanding.Its unique ecological adaptability and environmentally friendly characteristics help to reduce dependence on chemical pesticides,ensure the safety of agricultural products and maintain ecological diversity.The purpose of this study is to analyze the current situation of natural enemy insect industry,evaluate its cost and benefit,emphasize its great significance in promoting the transformation of green agriculture,improving production efficiency and promoting ecological protection by drawing lessons from foreign successful experiences,and explore an efficient and sustainable new agricultural development model.
基金the financial support from the National Natural Science Foundation of China(62021003,61890930-5,61903012,62073006)Beijing Natural Science Foundation(42130232)the National Key Research and Development Program of China(2021ZD0112301,2021ZD0112302)。
文摘Air pollution control poses a major problem in the implementation of municipal solid waste incineration(MSWI).Accurate prediction of nitrogen oxides(NO_(x))concentration plays an important role in efficient NO_(x)emission controlling.In this study,a modular long short-term memory(M-LSTM)network is developed to design an efficient prediction model for NO_(x)concentration.First,the fuzzy C means(FCM)algorithm is utilized to divide the task into several sub-tasks,aiming to realize the divide-and-conquer ability for complex task.Second,long short-term memory(LSTM)neural networks are applied to tackle corresponding sub-tasks,which can improve the prediction accuracy of the sub-networks.Third,a cooperative decision strategy is designed to guarantee the generalization performance during the testing or application stage.Finally,after being evaluated by a benchmark simulation,the proposed method is applied to a real MSWI process.And the experimental results demonstrate the considerable prediction ability of the M-LSTM network.
基金Supported by Humanities and Sociology Research Project for Colleges and Universities of Guizhou Province(2022ZC016).
文摘Starting from the effects of diseases and pests on tea quality,tea industry and export trade,the status quo and control of tea diseases and pests,assurance and traceability of tea quality safety,tea industry and export trade development are analyzed in detail,and green prevention and control measures against tea diseases and pests are put forward combined with the status quo of tea in China.
基金Supported by Autonomous Project of the Key Laboratory for Cultivating Excellent Timber Forest Resources in Guangxi (2020-A-04-01)Special Fund of Guangxi Innovation Driven Development (GUIKE AA17204087-11)。
文摘Soil information is the basis of soil management and precise variable fertilization. The traditional method of obtaining soil information through chemical detection of laboratory has high cost and poor timeliness, which is difficult to meet the needs of digital forestry, soil monitoring and real-time management of nutrients. Taking red soil of Eucalyptus plantation in northern Guangxi as the research object, the spectral data of samples with different soil available potassium contents were measured, and the spectral characteristics were analyzed, and the inversion model was established by using PLS method. The results showed that the spectral sensitive bands of available potassium content in red soil of the region mainly concentrated in 400-600, 1 450, 2 200 nm and so on. After the first derivative transformation, the redundant information in the original spectral data can be significantly reduced, and the correlation between spectral indexes and soil available potassium content can be improved. The full-band modeling results of R and FDR were better than those of significant bands. The optimal model was full-band-FDR-PLS, R2=0.862, and RMSE=2.718. The results of this study can be used for the application of near-earth remote sensing in Guangxi, such as soil digital mapping, precise variable fertilization and real-time monitoring of soil available potassium.
基金Supported by Humanities and Social Science Research Project of Universities in Guizhou Province(2022ZC016)。
文摘As a traditional advantageous industry in Guizhou and an important export product,tea plays an important role in the rural revitalization strategy.This paper first introduces the current situation of tea industry and export in Guizhou,then analyzes the problems that arise in the export process,and finally comes up with corresponding countermeasures and recommendations for the export development of tea,hoping to provide certain guidance and reference to the development of tea industry in Guizhou Province.
基金Supported by National Natural Science Foundation of China(Grant No.51705531)Jiangsu Provincial Natural Science Foundation of China(Grant No.BK20150724)
文摘Hydraulic systems have the characteristics of strong fault concealment,powerful nonlinear time-varying signals,and a complex vibration transmission mechanism;hence,diagnosis of these systems is a challenge.To provide accurate diagnosis results automatically,numerous studies have been carried out.Among them,signal-based methods are commonly used,which employ signal processing techniques based on the state signal used for extracting features,and further input the features into the classifier for fault recognition.However,their main deficiencies include the following:(1)The features are manually designed and thus may have a lack of objectivity.(2)For signal processing,feature extraction and pattern recognition are conducted using independent models,which cannot be jointly optimized globally.(3)The machine learning algorithms adopted by these methods have a shallow architecture,which limits their capacity to deeply mine the essential features of a fault.As a breakthrough in artificial intelligence,deep learning holds the potential to overcome such deficiencies.Based on deep learning,deep neural networks(DNNs)can automatically learn the complex nonlinear relations implied in a signal,can be globally optimized,and can obtain the high-level features of multi-dimensional data.In this paper,the main technology used in an intelligent fault diagnosis and the current research status of hydraulic system fault diagnosis are summarized and analyzed.The significant prospect of applying deep learning in the field of intelligent fault diagnosis is presented,and the main ideas,methods,and principles of several typical DNNs are described and summarized.The commonality between a fault diagnosis and other issues regarding typical pattern recognition are analyzed,and research ideas for applying DNNs for hydraulic fault diagnosis are proposed.Meanwhile,the research advantages and development trend of DNNs(both domestically and overseas)as applied to an intelligent fault diagnosis are reviewed.Furthermore,the fault characteristics of a complex hydraulic system are summarized and discussed,and the key problems and possible research ideas of applying DNNs to an intelligent hydraulic fault diagnosis are presented and comprehensively analyzed.
基金supported by the National Natural Science Foundation of China,No.81401791,81371968,81672152
文摘Numerous studies have shown that topical application of mitomycin C after surgical decompression effectively reduces scar adhesion. However, the underlying mechanisms remain unclear. In this study, we investigated the effect of mitomycin C on the proliferation and apoptosis of human epidural scar fibroblasts. Human epidural scar fibroblasts were treated with various concentrations of mitomycin C （1, 5, 10, 20, 40 μg/mL） for 12, 24 and 48 hours. Mitomycin C suppressed the growth of these cells in a dose- and time-dependent manner. Mitomycin C upregulated the expression levels of Fas, DR4, DR5, cleaved caspase-8/9, Bax, Bim and cleaved caspase-3 proteins, and it downregulated Bcl-2 and Bcl-xL expression. In addition, inhibitors of caspase-8 and caspase-9 （Z-IETD-FMK and Z-LEHD-FMK, respectively） did not fully inhibit mitomycin C-induced apoptosis. Furthermore, mitomycin C induced endoplasmic reticulum stress by increasing the expression of glucose-regulated protein 78, CAAT/enhancer-binding protein homologous protein （CHOP） and caspase 4 in a dose-dependent manner. Salubrinal significantly inhibited the mitomycin C-induced cell viability loss and apoptosis, and these effects were accompanied by a reduction in CHOP expression. Our results support the hypothesis that mitomycin C induces human epidural scar fibroblast apoptosis, at least in part, via the endoplasmic reticulum stress pathway.
基金supported by Natural Science Foundation of China,No.81500455
文摘The outcomes of hepatitis B virus(HBV) infection are closely related to the age at which infection was acquired. Infection acquired in adult life tends to be selflimited, in contrast to perinatal acquirement, for which chronic persistence of the HBV is a general outcome. Innate immunity plays an indispensable role in early virus infection, facilitating virus clearance. However, it has been reported that HBV is under-recognized and poorly eliminated by the innate immune system in the early stages of infection, possibly explaining the long-lasting persistence of viremia afterwards. Furthermore, due to the existence of covalently closed circular DNA, chronic HBV clearance is very difficult, even when patients are given interferon-α and nucleotide/nucleoside analogs for antiviral therapy. The mechanism by which HBV evades innate immune recognition and establishes persistent infection remains a subject of debate. Besides, some researchers are becoming more interested in how to eradicate chronic HBV infection by restoring or boosting innate immunity. This review aimed to summarize the current knowledge on how intrahepatocyte signaling pathways and innate immune cells act after the onset of HBV infection and how these actions are related to the persistence of HBV. We anticipate the insights presented herein to be helpful for future development of novel immune therapeutic strategies to fight HBV infection.
基金Supported by the Health Commission of Zhejiang Province,No.2019KY690。
文摘BACKGROUND The value of conventional magnetic resonance imaging in the differential diagnosis of thyroid nodules is limited;however,the value of multi-parameter diffusion-weighted imaging(DWI)in the quantitative evaluation of thyroid nodules has not been well determined.AIM To determine the utility of multi-parametric DWI including mono-exponential,biexponential,stretched exponential,and kurtosis models for the differentiation of thyroid lesions.METHODS Seventy-nine patients(62 with benign and 17 with malignant nodules)underwent multi-b value diffusion-weighted imaging of the thyroid.Multiple DWI parameters were obtained for statistical analysis.RESULTS Good agreement was found for diffusion parameters of thyroid nodules.Malignant lesions displayed lower diffusion parameters including apparent diffusion coefficient(ADC),the true diffusion coefficient(D),the perfusion fraction(f),the distributed diffusion coefficient(DDC),the intravoxel water diffusion heterogeneity(α)and kurtosis model-derived ADC(Dapp),and higher apparent diffusional kurtosis(Kapp)than benign entities(all P<0.01),except for the pseudodiffusion coefficient(D*)(P>0.05).The area under the ROC curve(AUC)of the ADC(0 and 1000)was not significantly different from that of the ADC(0 and 2000),ADC(0 to 2000),ADC(0 to 1000),D,DDC,Dapp and Kapp(all P>0.05),but was significantly higher than the AUC of D*,f andα(all P<0.05)for differentiating benign from malignant lesions.CONCLUSION Multiple DWI parameters including ADC,D,f,DDC,α,Dapp and Kapp could discriminate benign and malignant thyroid nodules.The metrics including D,DDC,Dapp and Kapp provide additional information with similar diagnostic performance of ADC,combination of these metrics may contribute to differentiate benign and malignant thyroid nodules.The ADC calculated with higher b values may not lead to improved diagnostic performance.
基金The National Natural Science Foundation of China, No. 30470877Chinese Postdoctoral Science Foundation, No. 20070420754the Natural Science Foundation of Fujian Province of China, No. 2008J0302
文摘AIM： To explore the existence and distribution of prohibitin （PHB） in nuclear matrix and its co-localization with products of some related genes during the differentiation of human hepatocarcinoma SNMC-7721 cells. METHODS： The nuclear matrix of the SMMC-7721 cells cultured with or without 5 × 10^-3 mmol/L hexamethylene bisacetamide （HNBA） was selectively extracted. Western blot was used to analyze the expression of PHB in nuclear matrix; immunofluorescence microscope observation was used to analyze the distribution of PHB in cell. LCSM was used to observe the co-localization of PHB with products of oncogenes and tumor suppressor genes. RESULTS： Western blot analysis showed that PHB existed in the composition of nuclear matrix proteins and was down-regulated by HMBA treatment. Immunofluorescence observation revealed that PHB existed in the nuclear matrix, and its distribution regions and expression levels were altered after HMBA treatment. Laser scanning confocal microscopy revealed the co-localization between PHB and the products of oncogenes or tumor repression genes including c-los, c-myc, p53 and Rb and its alteration of distributive area in the cells treated by HMBA. CONCLUSION： These data confirm that PHB is a nuclear matrix protein, which is located in the nuclear matrix, and the distribution and expression of PHB and its relation with associated genes may play significant roles during the differentiation of SMMC-7721 cells.
基金Supported by the National Natural Science Foundation of China, No. 30470877
文摘AIM： To investigate the association between the configurational and compositional changes of nuclear matrix and the differentiation of carcinoma cells. METHODS： Cells cultured with or without 5 × 10^-3 mmol/L of hexamethylene bisacetamide （HMBA） on Nickel grids were treated by selective extraction and prepared for whole mount observation under electron microscopy. The samples were examined under transmission electron microscope. Nuclear matrix proteins were selectively extracted and subjected to subcellular proteomics study. The protein expression patterns were analyzed by PDQuest software. Spots of differentially expressed nuclear matrix proteins were excised and subjected to in situ digestion with trypsin. The peptides were analyzed by matrix-assisted laser- desorption/ionization time of flight mass spectrometry （MALDI-TOF-MS）. Data were submitted for database searching using Mascot tool （www.matrixscience.com）. RESULTS： The nuclear matrix （NM） and intermediate filament （IF） in SMMC-7721 hepatocarcinoma cells were found relatively sparse and arranged irregularly. The nuclear lamina was non-uniform, and two kinds of filaments were not tightly connected. After induction for differentiation by HMBA, the NM-IF filaments were concentrated and distributed uniformly. The heterogeneous population of filaments, including highly branched utrathin filaments could also be seen in the regular meshwork. The connection between the two kinds of filaments and the relatively thin, condensed and sharply demarcated lamina composed of intermediate- sized filaments was relatively fastened. Meanwhile, 21 NM proteins changed remarkably during SMMC-7721 cell differentiation. Four proteins, i.e. mutant Pystl, hypothetical protein, nucleophosminl, and LBP were downregulated, whereas four other proteins, eIF6, p44 subunit, 13-tubulin, and SIN3B were upregulated with the last one, SR2/ASF found only in the differentiated SMMC-7721 cells. CONCLUSION： The induced differentiation of SMMC-7721 cells by HMBA is accompanied by the configurational changes of nuclear matrix-intermediate filament （NM-IF） system and the compositional changes of nuclear matrix protein expression. These changes may be important morphological or functional indications of the cancer cell reversion.
基金the financial supports from the National Natural Science Foundation of China(Nos.52161040,51862026)the Natural Science Foundation of Jiangxi Province,China(Nos.20202ACBL214011,20192ACBL21048)the Aeronautical Science Foundation of China(No.2017ZF56027)。
文摘The Ni−MoO_(2) heterostructure was synthesized in suit on porous bulk NiMo alloy by a facile powder metallurgy and hydrothermal method.The results of field emission scanning electron microscopy(SEM),field emission transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS)reveal that the as-prepared electrode possesses the heterostructure and a layer of Ni(OH)_(2) nanosheets is formed on the surface of Ni−MoO_(2) electrode simultaneously after hydrothermal treatment,which provides abundant interface and much active sites,as well as much active specific surface area.The results of hydrogen evolution reaction indicate that the Ni−MoO_(2) heterostructure electrode exhibits excellent catalytic performance,requiring only 41 mV overpotential to reach the current density of 10 mA/cm^(2).It also possesses a small Tafel slope of 52.7 mV/dec and long-term stability of electrolysis in alkaline medium.
基金supported by the National Natural Science Foundation of China(61535012,61925505)the National Key R&D Program of China(2018YFB2201900)。
文摘A modulator is an essential building block in the integrated photonics,connecting the electrical with optical signals.The microring modulator gains much attention because of the small footprint,low drive voltage and high extinction ratio.An ultra-low V_(pp)and high-modulation-depth indium phosphide-based racetrack microring modulator is demonstrated in this paper.The proposed device mainly comprises one racetrack microring,incorporating a semiconductor amplifier,and coupling with a bus waveguide through a multimode interference coupler.Traveling wave electrodes are employed to supply bidirectional bias ports,terminating with a 50-Ω impedance.The on/off extinction ratio of the microring reaches 43.3 dB due to the delicately tuning of the gain.An 11 mV V_(pp),a maximum 42.5 dB modulation depth and a 6.6 GHz bandwidth are realized,respectively.This proposed microring modulator could enrich the functionalities and designability of the fundamental integrated devices.
基金the National Key R&D Program of China(Nos.2018YFC1503401,and 2016ZX05023004)National Natural Science Foundation of China(Nos.4217040570,and 41674059).
文摘The joint source scanning algorithm(SSA)scans locations and focal mechanisms of microseismic events simultaneously.Compared to the traditional source scanning algorithm,it yields much more events with extra information of focal mechanisms.The availability of more events and focal mechanisms make it possible to invert for a 2D gridded stress field.As a byproduct of hydrofracturing monitoring,the method offers a new way to extract stress field as a substitute to other more expensive technologies.This method is applied to a hydraulic fracturing dataset collected from one shale gas production field in the southeast of the Sichuan basin.A damped stress inversion is conducted to obtain a 2D stress field.five hydraulic-fracturing induced fractures can be determined from the result.The events associated with these fractures generally have relatively low stacked energy and are limited to the depth of horizontal well.One existing fault(possibly associated with the axis of the central Sichuan uplift)is also determined and the events associated with the existing fault generally have higher stacked energy and are more densely populated.The existing fault may also serve as a structural boundary where the rocks to the NW side are easier to be fractured while events on the other side are sparse with low stacked energy.The existing fault also divides the stress field into two regimes:the maximum compressional stress field to the NW and SE of the fault line are dominantly in NW-SE and N-S directions,respectively.
