Fifteen novel carbazole alkaloids,euchrestifolines A-O(1-15),were obtained from Murraya euchrestifolia.Their structures were elucidated by spectroscopic analysis,Mosher's ester,calculated ECD,and transition metal ...Fifteen novel carbazole alkaloids,euchrestifolines A-O(1-15),were obtained from Murraya euchrestifolia.Their structures were elucidated by spectroscopic analysis,Mosher's ester,calculated ECD,and transition metal complex ECD methods.Notably,euchrestifolines A-C(1-3)are the first naturally occurring pyrrolidone carbazoles to be identified,while euchrestifolines D-F(4-6)represent rare carbazole alkaloids containing a phenylpropanyl moiety;euchrestifoline G(7)features a unique benzopyranocarbazole skeleton.More importantly,these compounds exhibited significant anti-ferroptotic activity,along with inhibitory effects of nitric oxide(NO)production and notable cytotoxicity.This study marks the first disclosure of carbazole's inhibitory effects against ferroptosis,and the EC_(50) values of some carbazoles ranging from 0.04 to 1 μM,substantially lower than the positive control,ferrostatin-1.In sum,this research not only enhances our understanding of carbazole alkaloids but also opens new avenues for the discovery of ferroptosis-related leading compounds.展开更多
BACKGROUND Bladder cancer is a type of cancer with a high incidence in men.Plasma electrosurgery(PES)is often used in the treatment of bladder cancer.Postoperative complications often cause depression and anxiety in p...BACKGROUND Bladder cancer is a type of cancer with a high incidence in men.Plasma electrosurgery(PES)is often used in the treatment of bladder cancer.Postoperative complications often cause depression and anxiety in patients after surgery.AIM To investigate the current state of depression and anxiety after PES in patients with non-muscle-invasive bladder cancer and analyze the factors affecting them.METHODS A retrospective study was conducted to compare the baseline data of patients by collecting their medical history and grouping them according to their mental status into negative and normal groups.Logistic regression analysis was used to explore the risk factors affecting the occurrence of anxiety and depression after surgery in patients with bladder cancer.RESULTS Comparative analyses of baseline differences showed that the patients in the negative and normal groups differed in terms of their first surgery,economic status,educational level,and marital status.A logistic regression analysis showed that it affected the occurrence of anxiety in patients with bladder cancer,and the results showed that whether the risk factors were whether or not it was the first surgery,monthly income between 3000 and 3000-6000,secondary or junior high school education level,single,divorced,and widowed statuses.CONCLUSION The risk factors affecting the onset of anxiety and depression in bladder cancer patients after PES are the number of surgeries,economic status,level of education,and marital status.This study provides a reference for the clinical treatment and prognosis of bladder cancer patients in the future.展开更多
Continuum robots with high flexibility and compliance have the capability to operate in confined and cluttered environments. To enhance the load capacity while maintaining robot dexterity, we propose a novel non-const...Continuum robots with high flexibility and compliance have the capability to operate in confined and cluttered environments. To enhance the load capacity while maintaining robot dexterity, we propose a novel non-constant subsegment stiffness structure for tendon-driven quasi continuum robots(TDQCRs) comprising rigid-flexible coupling subsegments.Aiming at real-time control applications, we present a novel static-to-kinematic modeling approach to gain a comprehensive understanding of the TDQCR model. The analytical subsegment-based kinematics for the multisection manipulator is derived based on screw theory and product of exponentials formula, and the static model considering gravity loading,actuation loading, and robot constitutive laws is established. Additionally, the effect of tension attenuation caused by routing channel friction is considered in the robot statics, resulting in improved model accuracy. The root-mean-square error between the outputs of the static model and the experimental system is less than 1.63% of the arm length(0.5 m). By employing the proposed static model, a mapping of bending angles between the configuration space and the subsegment space is established. Furthermore, motion control experiments are conducted on our TDQCR system, and the results demonstrate the effectiveness of the static-to-kinematic model.展开更多
Skin defect inspection is one of the most significant tasks in the conventional process of aircraft inspection.This paper proposes a vision-based method of pixel-level defect detection,which is based on the Mask Scori...Skin defect inspection is one of the most significant tasks in the conventional process of aircraft inspection.This paper proposes a vision-based method of pixel-level defect detection,which is based on the Mask Scoring R-CNN.First,an attention mechanism and a feature fusion module are introduced,to improve feature representation.Second,a new classifier head—consisting of four convolutional layers and a fully connected layer—is proposed,to reduce the influence of information around the area of the defect.Third,to evaluate the proposed method,a dataset of aircraft skin defects was constructed,containing 276 images with a resolution of 960×720 pixels.Experimental results show that the proposed classifier head improves the detection and segmentation accuracy,for aircraft skin defect inspection,more effectively than the attention mechanism and feature fusion module.Compared with the Mask R-CNN and Mask Scoring R-CNN,the proposed method increased the segmentation precision by approximately 21%and 19.59%,respectively.These results demonstrate that the proposed method performs favorably against the other two methods of pixellevel aircraft skin defect detection.展开更多
Graphene-like C3N4/Ag3PO4 photocatalysts are synthesized by calcination and solutions precipitating method.The obtained g-C3N4/Ag3PO4 composites display excellent photocatalytic activity for the degradation of methyle...Graphene-like C3N4/Ag3PO4 photocatalysts are synthesized by calcination and solutions precipitating method.The obtained g-C3N4/Ag3PO4 composites display excellent photocatalytic activity for the degradation of methylene orange(MO),rhodamine B(RhB)and tetracycline(TC)under visible light irradiation.The solutions containing RhB(10 mg/L)and MO(10 mg/L)can be efficiently degraded within15 min and 30 min.Especially,nearly 80%of TC(50 mg/L)is degraded within 20 min.which are much better than those of pure g-C3N4 nanosheets and Ag3PO4,implying that strong interaction and reasonable energy band alignment in the contact interface can effectively transfer the carries.Furthermore,the g-C3N4/Ag3PO4 composites exhibit the improved stability,and only a slight decrease is observed after three recycling runs.Moreover,the impact of inorganic ions and PH values on the degradation performance is rather small.The Z-scheme photocatalytic mechanism of the g-C3N4/Ag3PO4 composites based on the active species trapping experimental is proposed.This work demonstrates the promising applications of the g-C3N4/Ag3PO4 composites in environmental issues.展开更多
Bacterial biofilm infections have been threatening the human’s life and health globally for a long time because they typically cause chronic and persistent infections.Traditional antibiotic therapies can hardly eradi...Bacterial biofilm infections have been threatening the human’s life and health globally for a long time because they typically cause chronic and persistent infections.Traditional antibiotic therapies can hardly eradicate biofilms in many cases,as biofilms always form a robust fortress for pathogens inside,inhibiting the penetration of drugs.To address the issues,many novel drug carriers emerged as promising strategies for biofilm treatment.Among them,stimuli-responsive nanocarriers have attracted much attentions for their intriguing physicochemical properties,such as tunable size,shape and surface chemistry,especially smart drug release characteristic.Based on the microenvironmental difference between biofilm infection sites and normal tissue,many stimuli,such as bacterial products accumulating in biofilms(enzymes,glutathione,etc.),lower pH and higher H_(2)O_(2)levels,have been employed and proved in favor of“on-demand”drug release for biofilm elimination.Additionally,external stimuli including light,heat,microwave and magnetic fields are also able to control the drug releasing behavior artificially.In this review,we summarized recent advances in stimuli-responsive nanocarriers for combating biofilm infections,and mainly,focusing on the different stimuli that trigger the drug release.展开更多
Gold nanoparticles （NPs） of various shapes were synthesized by a one-step method at ambient temperature in the presence of NaCl. 2-mercaptosuccinic acid （MSA） was used as both reducing agent and stabilizing agent....Gold nanoparticles （NPs） of various shapes were synthesized by a one-step method at ambient temperature in the presence of NaCl. 2-mercaptosuccinic acid （MSA） was used as both reducing agent and stabilizing agent. The shapes of gold NPs were controllable by simply tuning S/Au ratio （S is from MSA molecule, and S/Au ratio is controlled by tuning the volume of added MSA solution）, and triangle, polygonal and spherical nanoparticles were obtained. This result suggested a new way to consider the effects of MSA on the growth of nanoparticles, which showed that MSA is a strong capping agent and facilitates more uniform growth of nanoparticles in every dimension. And other important factors on nanoparticles growth including NaCl and temperature were discussed. Furthermore, a typical probe molecule, 4-aminothiophenol （4-ATP） was used to test the surface-enhanced Raman scattering （SERS） activity of these gold NPs and the results indicated good Raman activity on these substrates. And the enhancement factor （EF） at 1078 cm^- 1 （a1） was estimated to be as large as 6.3 × 10^4 and 5.5 × 10^4 for triangular plates and truncated particles, respectively.展开更多
With the rapid development of Internet technology,the type of information in the Internet is extremely complex,and a large number of riot contents containing bloody,violent and riotous components have appeared.These c...With the rapid development of Internet technology,the type of information in the Internet is extremely complex,and a large number of riot contents containing bloody,violent and riotous components have appeared.These contents pose a great threat to the network ecology and national security.As a result,the importance of monitoring riotous Internet activity cannot be overstated.Convolutional Neural Network(CNN-based)target detection algorithm has great potential in identifying rioters,so this paper focused on the use of improved backbone and optimization function of You Only Look Once v5(YOLOv5),and further optimization of hyperparameters using genetic algorithm to achieve fine-grained recognition of riot image content.First,the fine-grained features of riot-related images were identified,and then the dataset was constructed by manual annotation.Second,the training and testing work was carried out on the constructed dedicated dataset by supervised deep learning training.The research results have shown that the improved YOLOv5 network significantly improved the fine-grained feature extraction capability of riot-related images compared with the original YOLOv5 network structure,and the mean average precision(mAP)value was improved to 0.6128.Thus,it provided strong support for combating riot-related organizations and maintaining the online ecological environment.展开更多
The DArk Matter Particle Explorer(DAMPE) is a space-borne apparatus for detecting the highenergy cosmic-ray-like electrons, γ-rays, protons and heavy ions. The Plastic Scintillator Detector(PSD)is the top-most sub-de...The DArk Matter Particle Explorer(DAMPE) is a space-borne apparatus for detecting the highenergy cosmic-ray-like electrons, γ-rays, protons and heavy ions. The Plastic Scintillator Detector(PSD)is the top-most sub-detector of the DAMPE. The PSD is designed to measure the charge of incident highenergy particles and it also serves as a veto detector for discriminating γ-rays from charged particles. In this paper, a PSD on-orbit calibration procedure is described, which includes the five steps of pedestal, dynode correlation, response to minimum-ionizing particles, light attenuation function and energy reconstruction.A method for reconstructing the charge of incident high energy cosmic-ray particles is introduced. The detection efficiency of each PSD strip is verified to be above 99.5%; the total efficiency of the PSD for charged particles is above 99.99%.展开更多
With the rapid development of China’s economy and society,the concept of innovation is deeply rooted in the hearts of the people,and the construction of an innovative country is imminent.As a cradle of cultivating ta...With the rapid development of China’s economy and society,the concept of innovation is deeply rooted in the hearts of the people,and the construction of an innovative country is imminent.As a cradle of cultivating talents,how to effectively enhance college students’awareness of innovation and entrepreneurship,how to effectively improve college students’innovation and entrepreneurship,and how to effectively cultivate college students’ability to innovate and innovate is very important and urgent.Innovative entrepreneurship as a complex social giant system,training contemporary college students’awareness of innovation and entrepreneurship is the key.Based on the idea of"granting people and fishing"and applying practice as the purpose,this paper starts with the analysis of the current situation of the cultivation of college students’innovation and entrepreneurship awareness,the goal of cultivating contemporary college students’awareness of innovation and entrepreneurship,and the basic strategy for cultivating innovation and entrepreneurship awareness.展开更多
In a hollow-core fiber(HCF),light propagates through an air/vacuum core rather than a solid material,resulting in a low thermo-optic coefficient and ability to handle high powers.Here,we demonstrate a laser locked to ...In a hollow-core fiber(HCF),light propagates through an air/vacuum core rather than a solid material,resulting in a low thermo-optic coefficient and ability to handle high powers.Here,we demonstrate a laser locked to a hollow-core fiber reference,which thanks to the low HCF thermal sensitivity,shows long-term stability an order of magnitude better than compact commercially available low-noise lasers.The laser frequency variation within±600 kHz was measured over 50 h.The stability of our proof-of-concept laser is ensured via a strong selfinjection ratio of-15 dB,enabled by the high-power handling and low loss of the hollow-core fiber's resonator.Moreover,our results show appealing performance parameters,including a fractional frequency stability of4×10^(-13)at 1 s averaging time and a Lorentzian component of the linewidth of 0.2 Hz.展开更多
Objective:The absorbed prototypes and metabolites of traditional Chinese medicines in vivo are crucial for identifying their biological functions.However,comprehensive profiling of constituents in vivo is difficult ow...Objective:The absorbed prototypes and metabolites of traditional Chinese medicines in vivo are crucial for identifying their biological functions.However,comprehensive profiling of constituents in vivo is difficult owing to endogenous interference and low metabolite abundance.Therefore,a systematic strategy was proposed for screening and profiling exogenous components in biological matrices based on the mass differences between prototypes and the products of their metabolic reactions.Materials and Methods:Two hundred and forty-seven previously reported metabolic reactions were collected from the relevant literature on the Huangqi-Danshen(HD)herb pair,and a metabolic reaction-based mass difference database was created.The preprocessed data from experimental MS1based on ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry were automatically calculated mass differences by R programming and matched with the database to screen potential constituents.Finally,the components were annotated across the MS2data.Results:A total of 164 components were annotated in the plasma samples from the rats after oral administration of HD,of which 20 were confirmed using the reference standards.The major metabolic pathways include methylation,dehydration,cysteine S-binding,glucuronidation,sulfation,and multistep reactions.Conclusions:This study revealed the metabolic characteristics and biotransformation regulation of HD and laid the foundation for elucidating its therapeutic effects.The proposed approach provides advantageous resources for evaluating the metabolites in the complex systems.展开更多
Soluble sugar and organic acids are key determinants of fruit organoleptic quality and directly affect the commodity value and economic returns of fruit crops.We performed whole-genome sequencing of the apple varietie...Soluble sugar and organic acids are key determinants of fruit organoleptic quality and directly affect the commodity value and economic returns of fruit crops.We performed whole-genome sequencing of the apple varieties Gala and Xiahongrou,along with their F1 hybrids,to construct a high-density bin map.Our quantitative genetic analysis pinpointed 53 quantitative trait loci(QTLs)related to 11 sugar and acid traits.We identified a candidate gene,MdNADP-ME,responsible for malate degradation,in a stable QTL on linkage group 15.Sequence analysis revealed an A/C SNP in the promoter region(MEp-799)that influences binding of the MdMYB2 transcription factor,thereby affecting MdNADP-ME expression.In our study of various apple genotypes,this SNP has been demonstrated to be linked to malate and fructose levels.We also developed a dCAPS marker associated with fruit fructose content.These results substantiate the role of MdNADP-ME in maintaining the equilibrium between sugar and acid contents in apple fruits.展开更多
Dear Editor,Obesity is caused by an imbalance between energy intake and expenditure,and has become a global epidemic with over 650 million adults affected.Adipose tissues in mammals are composed of white adipose tissu...Dear Editor,Obesity is caused by an imbalance between energy intake and expenditure,and has become a global epidemic with over 650 million adults affected.Adipose tissues in mammals are composed of white adipose tissue(WAT)and classical brown adipose tissue(BAT),and their balance is highly related to the occurrence of obesity.The browning of white adipocytes results in“beige”or“brite”adipocytes,which appear functionally similar to classical brown adipocytes,and can be detected in WAT deposits of animals that have been exposed to cold or other inducers(Fu et al.,2015).展开更多
基金the National Natural Science Foundation of China(NSFC)for their financial support through grant numbers 81973199,82173949,U23A20514,81773864,and 81473106the funding provided by the Key Research and Development Project of Shandong Province(2021CXGC010507).
文摘Fifteen novel carbazole alkaloids,euchrestifolines A-O(1-15),were obtained from Murraya euchrestifolia.Their structures were elucidated by spectroscopic analysis,Mosher's ester,calculated ECD,and transition metal complex ECD methods.Notably,euchrestifolines A-C(1-3)are the first naturally occurring pyrrolidone carbazoles to be identified,while euchrestifolines D-F(4-6)represent rare carbazole alkaloids containing a phenylpropanyl moiety;euchrestifoline G(7)features a unique benzopyranocarbazole skeleton.More importantly,these compounds exhibited significant anti-ferroptotic activity,along with inhibitory effects of nitric oxide(NO)production and notable cytotoxicity.This study marks the first disclosure of carbazole's inhibitory effects against ferroptosis,and the EC_(50) values of some carbazoles ranging from 0.04 to 1 μM,substantially lower than the positive control,ferrostatin-1.In sum,this research not only enhances our understanding of carbazole alkaloids but also opens new avenues for the discovery of ferroptosis-related leading compounds.
文摘BACKGROUND Bladder cancer is a type of cancer with a high incidence in men.Plasma electrosurgery(PES)is often used in the treatment of bladder cancer.Postoperative complications often cause depression and anxiety in patients after surgery.AIM To investigate the current state of depression and anxiety after PES in patients with non-muscle-invasive bladder cancer and analyze the factors affecting them.METHODS A retrospective study was conducted to compare the baseline data of patients by collecting their medical history and grouping them according to their mental status into negative and normal groups.Logistic regression analysis was used to explore the risk factors affecting the occurrence of anxiety and depression after surgery in patients with bladder cancer.RESULTS Comparative analyses of baseline differences showed that the patients in the negative and normal groups differed in terms of their first surgery,economic status,educational level,and marital status.A logistic regression analysis showed that it affected the occurrence of anxiety in patients with bladder cancer,and the results showed that whether the risk factors were whether or not it was the first surgery,monthly income between 3000 and 3000-6000,secondary or junior high school education level,single,divorced,and widowed statuses.CONCLUSION The risk factors affecting the onset of anxiety and depression in bladder cancer patients after PES are the number of surgeries,economic status,level of education,and marital status.This study provides a reference for the clinical treatment and prognosis of bladder cancer patients in the future.
基金Project supported by the National Natural Science Foundation of China (Grant No.61973167)the Jiangsu Funding Program for Excellent Postdoctoral Talent。
文摘Continuum robots with high flexibility and compliance have the capability to operate in confined and cluttered environments. To enhance the load capacity while maintaining robot dexterity, we propose a novel non-constant subsegment stiffness structure for tendon-driven quasi continuum robots(TDQCRs) comprising rigid-flexible coupling subsegments.Aiming at real-time control applications, we present a novel static-to-kinematic modeling approach to gain a comprehensive understanding of the TDQCR model. The analytical subsegment-based kinematics for the multisection manipulator is derived based on screw theory and product of exponentials formula, and the static model considering gravity loading,actuation loading, and robot constitutive laws is established. Additionally, the effect of tension attenuation caused by routing channel friction is considered in the robot statics, resulting in improved model accuracy. The root-mean-square error between the outputs of the static model and the experimental system is less than 1.63% of the arm length(0.5 m). By employing the proposed static model, a mapping of bending angles between the configuration space and the subsegment space is established. Furthermore, motion control experiments are conducted on our TDQCR system, and the results demonstrate the effectiveness of the static-to-kinematic model.
基金National Natural Science Foundation of China(Nos.U2033201 and U1633105)。
文摘Skin defect inspection is one of the most significant tasks in the conventional process of aircraft inspection.This paper proposes a vision-based method of pixel-level defect detection,which is based on the Mask Scoring R-CNN.First,an attention mechanism and a feature fusion module are introduced,to improve feature representation.Second,a new classifier head—consisting of four convolutional layers and a fully connected layer—is proposed,to reduce the influence of information around the area of the defect.Third,to evaluate the proposed method,a dataset of aircraft skin defects was constructed,containing 276 images with a resolution of 960×720 pixels.Experimental results show that the proposed classifier head improves the detection and segmentation accuracy,for aircraft skin defect inspection,more effectively than the attention mechanism and feature fusion module.Compared with the Mask R-CNN and Mask Scoring R-CNN,the proposed method increased the segmentation precision by approximately 21%and 19.59%,respectively.These results demonstrate that the proposed method performs favorably against the other two methods of pixellevel aircraft skin defect detection.
基金financially supported by the National Natural Science Foundation of China (Nos. 61504048, 51672109, 21707043)Natural Science Foundation of Shandong Province for Excellent Young Scholars (Nos. ZR2016JL015, ZR2017BEE005)
文摘Graphene-like C3N4/Ag3PO4 photocatalysts are synthesized by calcination and solutions precipitating method.The obtained g-C3N4/Ag3PO4 composites display excellent photocatalytic activity for the degradation of methylene orange(MO),rhodamine B(RhB)and tetracycline(TC)under visible light irradiation.The solutions containing RhB(10 mg/L)and MO(10 mg/L)can be efficiently degraded within15 min and 30 min.Especially,nearly 80%of TC(50 mg/L)is degraded within 20 min.which are much better than those of pure g-C3N4 nanosheets and Ag3PO4,implying that strong interaction and reasonable energy band alignment in the contact interface can effectively transfer the carries.Furthermore,the g-C3N4/Ag3PO4 composites exhibit the improved stability,and only a slight decrease is observed after three recycling runs.Moreover,the impact of inorganic ions and PH values on the degradation performance is rather small.The Z-scheme photocatalytic mechanism of the g-C3N4/Ag3PO4 composites based on the active species trapping experimental is proposed.This work demonstrates the promising applications of the g-C3N4/Ag3PO4 composites in environmental issues.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.51873212 and 51803212)the Youth Innovation Promotion Association of Chinese Academy Science(No.2017269)+1 种基金the Natural Science Foundation of Shandong Province(No.ZR2019MEM008)Chinese Academy of Sciences-Wego Group Hightech Research&Development Program.
文摘Bacterial biofilm infections have been threatening the human’s life and health globally for a long time because they typically cause chronic and persistent infections.Traditional antibiotic therapies can hardly eradicate biofilms in many cases,as biofilms always form a robust fortress for pathogens inside,inhibiting the penetration of drugs.To address the issues,many novel drug carriers emerged as promising strategies for biofilm treatment.Among them,stimuli-responsive nanocarriers have attracted much attentions for their intriguing physicochemical properties,such as tunable size,shape and surface chemistry,especially smart drug release characteristic.Based on the microenvironmental difference between biofilm infection sites and normal tissue,many stimuli,such as bacterial products accumulating in biofilms(enzymes,glutathione,etc.),lower pH and higher H_(2)O_(2)levels,have been employed and proved in favor of“on-demand”drug release for biofilm elimination.Additionally,external stimuli including light,heat,microwave and magnetic fields are also able to control the drug releasing behavior artificially.In this review,we summarized recent advances in stimuli-responsive nanocarriers for combating biofilm infections,and mainly,focusing on the different stimuli that trigger the drug release.
基金supported by the National Natural Science Foundation of China under Grant No.21101146
文摘Gold nanoparticles （NPs） of various shapes were synthesized by a one-step method at ambient temperature in the presence of NaCl. 2-mercaptosuccinic acid （MSA） was used as both reducing agent and stabilizing agent. The shapes of gold NPs were controllable by simply tuning S/Au ratio （S is from MSA molecule, and S/Au ratio is controlled by tuning the volume of added MSA solution）, and triangle, polygonal and spherical nanoparticles were obtained. This result suggested a new way to consider the effects of MSA on the growth of nanoparticles, which showed that MSA is a strong capping agent and facilitates more uniform growth of nanoparticles in every dimension. And other important factors on nanoparticles growth including NaCl and temperature were discussed. Furthermore, a typical probe molecule, 4-aminothiophenol （4-ATP） was used to test the surface-enhanced Raman scattering （SERS） activity of these gold NPs and the results indicated good Raman activity on these substrates. And the enhancement factor （EF） at 1078 cm^- 1 （a1） was estimated to be as large as 6.3 × 10^4 and 5.5 × 10^4 for triangular plates and truncated particles, respectively.
基金This work was supported by Fundamental Research Funds for the Central Universities,People’s Public Security University of China(2021JKF215)Key Projects of the Technology Research Program of the Ministry of Public Security(2021JSZ09)the Fund for the training of top innovative talents to support master’s degree program,People’s Public Security University of china(2021yjsky018).
文摘With the rapid development of Internet technology,the type of information in the Internet is extremely complex,and a large number of riot contents containing bloody,violent and riotous components have appeared.These contents pose a great threat to the network ecology and national security.As a result,the importance of monitoring riotous Internet activity cannot be overstated.Convolutional Neural Network(CNN-based)target detection algorithm has great potential in identifying rioters,so this paper focused on the use of improved backbone and optimization function of You Only Look Once v5(YOLOv5),and further optimization of hyperparameters using genetic algorithm to achieve fine-grained recognition of riot image content.First,the fine-grained features of riot-related images were identified,and then the dataset was constructed by manual annotation.Second,the training and testing work was carried out on the constructed dedicated dataset by supervised deep learning training.The research results have shown that the improved YOLOv5 network significantly improved the fine-grained feature extraction capability of riot-related images compared with the original YOLOv5 network structure,and the mean average precision(mAP)value was improved to 0.6128.Thus,it provided strong support for combating riot-related organizations and maintaining the online ecological environment.
基金funded by the National Key Research and Development Program of China (2016YFA0400201)supported by the National Natural Science Foundation of China (11673047,11673075, 11303107, U1738127 and U1738205)
文摘The DArk Matter Particle Explorer(DAMPE) is a space-borne apparatus for detecting the highenergy cosmic-ray-like electrons, γ-rays, protons and heavy ions. The Plastic Scintillator Detector(PSD)is the top-most sub-detector of the DAMPE. The PSD is designed to measure the charge of incident highenergy particles and it also serves as a veto detector for discriminating γ-rays from charged particles. In this paper, a PSD on-orbit calibration procedure is described, which includes the five steps of pedestal, dynode correlation, response to minimum-ionizing particles, light attenuation function and energy reconstruction.A method for reconstructing the charge of incident high energy cosmic-ray particles is introduced. The detection efficiency of each PSD strip is verified to be above 99.5%; the total efficiency of the PSD for charged particles is above 99.99%.
文摘With the rapid development of China’s economy and society,the concept of innovation is deeply rooted in the hearts of the people,and the construction of an innovative country is imminent.As a cradle of cultivating talents,how to effectively enhance college students’awareness of innovation and entrepreneurship,how to effectively improve college students’innovation and entrepreneurship,and how to effectively cultivate college students’ability to innovate and innovate is very important and urgent.Innovative entrepreneurship as a complex social giant system,training contemporary college students’awareness of innovation and entrepreneurship is the key.Based on the idea of"granting people and fishing"and applying practice as the purpose,this paper starts with the analysis of the current situation of the cultivation of college students’innovation and entrepreneurship awareness,the goal of cultivating contemporary college students’awareness of innovation and entrepreneurship,and the basic strategy for cultivating innovation and entrepreneurship awareness.
基金Engineering and Physical Sciences Research Council(EP/P030181/1)VACUUM(EP/W037440/1)Technology Agency of the Czech Republic(FW03010171)。
文摘In a hollow-core fiber(HCF),light propagates through an air/vacuum core rather than a solid material,resulting in a low thermo-optic coefficient and ability to handle high powers.Here,we demonstrate a laser locked to a hollow-core fiber reference,which thanks to the low HCF thermal sensitivity,shows long-term stability an order of magnitude better than compact commercially available low-noise lasers.The laser frequency variation within±600 kHz was measured over 50 h.The stability of our proof-of-concept laser is ensured via a strong selfinjection ratio of-15 dB,enabled by the high-power handling and low loss of the hollow-core fiber's resonator.Moreover,our results show appealing performance parameters,including a fractional frequency stability of4×10^(-13)at 1 s averaging time and a Lorentzian component of the linewidth of 0.2 Hz.
基金supported by the National Natural Science Foundation of China(Grant No.82173963)。
文摘Objective:The absorbed prototypes and metabolites of traditional Chinese medicines in vivo are crucial for identifying their biological functions.However,comprehensive profiling of constituents in vivo is difficult owing to endogenous interference and low metabolite abundance.Therefore,a systematic strategy was proposed for screening and profiling exogenous components in biological matrices based on the mass differences between prototypes and the products of their metabolic reactions.Materials and Methods:Two hundred and forty-seven previously reported metabolic reactions were collected from the relevant literature on the Huangqi-Danshen(HD)herb pair,and a metabolic reaction-based mass difference database was created.The preprocessed data from experimental MS1based on ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry were automatically calculated mass differences by R programming and matched with the database to screen potential constituents.Finally,the components were annotated across the MS2data.Results:A total of 164 components were annotated in the plasma samples from the rats after oral administration of HD,of which 20 were confirmed using the reference standards.The major metabolic pathways include methylation,dehydration,cysteine S-binding,glucuronidation,sulfation,and multistep reactions.Conclusions:This study revealed the metabolic characteristics and biotransformation regulation of HD and laid the foundation for elucidating its therapeutic effects.The proposed approach provides advantageous resources for evaluating the metabolites in the complex systems.
基金upported by the National Key Research and Development Program of China,“Physiological basis and regulation of fruit tree quality and high yield”(2019YFD1000103)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Soluble sugar and organic acids are key determinants of fruit organoleptic quality and directly affect the commodity value and economic returns of fruit crops.We performed whole-genome sequencing of the apple varieties Gala and Xiahongrou,along with their F1 hybrids,to construct a high-density bin map.Our quantitative genetic analysis pinpointed 53 quantitative trait loci(QTLs)related to 11 sugar and acid traits.We identified a candidate gene,MdNADP-ME,responsible for malate degradation,in a stable QTL on linkage group 15.Sequence analysis revealed an A/C SNP in the promoter region(MEp-799)that influences binding of the MdMYB2 transcription factor,thereby affecting MdNADP-ME expression.In our study of various apple genotypes,this SNP has been demonstrated to be linked to malate and fructose levels.We also developed a dCAPS marker associated with fruit fructose content.These results substantiate the role of MdNADP-ME in maintaining the equilibrium between sugar and acid contents in apple fruits.
文摘Dear Editor,Obesity is caused by an imbalance between energy intake and expenditure,and has become a global epidemic with over 650 million adults affected.Adipose tissues in mammals are composed of white adipose tissue(WAT)and classical brown adipose tissue(BAT),and their balance is highly related to the occurrence of obesity.The browning of white adipocytes results in“beige”or“brite”adipocytes,which appear functionally similar to classical brown adipocytes,and can be detected in WAT deposits of animals that have been exposed to cold or other inducers(Fu et al.,2015).
