The right bank of the Amu Darya Basin enjoys abundant natural gas resources,on which the Callovian-Oxfordian strata in the middle of Block B serve as the major horizons for natural gas production.However,the character...The right bank of the Amu Darya Basin enjoys abundant natural gas resources,on which the Callovian-Oxfordian strata in the middle of Block B serve as the major horizons for natural gas production.However,the characteristics and distribution patterns of the sedimentary microfacies in these strata are yet to be further explored.Based on the analysis of data on drilling,logging,cores,and thin sections from 29 typical wells,as well as the regional sedimentary background,this study inferred that the middle of Block B evolved from the Callovian ramp platform into the Oxfordian rimmed platform.Moreover,this study determined that the inner-ramp intertidal-subtidal shallow-water subfacies mainly developed during the Callovian and transitioned into the shallow shelf subfacies during the Oxfordian.This study identified eight sedimentary microfacies,namely reef knoll,reef-shoal complex,bioclastic shoal,psammitic shoal,bioherm,lime mud mound,intershoal(intermound),and static-water mud.Based on research into the high-precision sequence-sedimentary microfacies framework,this study built a geological model for the development of sedimentary microfacies in the study area.According to this geological model,the sedimentary microfacies in the study area are characterized by vertical alternation of reef-shoal complex,bioclastic(psammitic)shoal,bioherm,and intershoal microfacies.Moreover,they show the development of reef knoll,reef-shoal complex,bioclastic(psammitic)shoal,and bioherm(or lime mud mound)laterally from west to east,with the physical properties of the reservoirs deteriorating from west to east accordingly.The microfacies of reef-shoal complex and the bioclastic(psammitic)shoal predominate in the study area,and their deposition and development are controlled by sequence boundaries and are also affected by paleo-landforms.The Oxfordian reef-shoal complexes were largely inherited from the Callovian uplifts and show lateral seaward progradation.展开更多
The dual-rotor structure serves as the primary source of vibration in aero-engines. Understanding itsdynamical model and analyzing dynamic characteristics, such as critical speed and unbalanced response, arecrucial fo...The dual-rotor structure serves as the primary source of vibration in aero-engines. Understanding itsdynamical model and analyzing dynamic characteristics, such as critical speed and unbalanced response, arecrucial for rotor system dynamics. Previous work introduced a coaxial dual-rotor-support scheme for aeroengines,and a physical model featuring a high-speed flexible inner rotor with a substantial length-to-diameter ratiowas designed. Then a finite element (FE) dynamic model based on the Timoshenko beam elements and rigid bodykinematics of the dual-rotor system is modeled, with the Newmark method and Newton–Raphson method used forthe numerical calculation to study the dynamic characteristics of the system. Three different simulation models,including beam-based FE (1D) model, solid-based FE (3D) model, and transfer matrix model, were designed tostudy the characteristics of mode and the critical speed characteristic of the dual-rotor system. The unbalancedresponse of the dual-rotor system was analyzed to study the influence of mass unbalance on the rotor system. Theeffect of different disk unbalance phases and different speed ratios on the dynamic characteristics of the dual-rotorsystem was investigated in detail. The experimental result shows that the beam-based FE model is effective andsuitable for studying the dual-rotor system.展开更多
Baicalin, a type of flavonoid extracted from the dried root of Scutellaria baicalensis georgi, has been shown to effectively inhibit cell apoptosis. Therefore, we assumed that baicalin would suppress colistin sulfate-...Baicalin, a type of flavonoid extracted from the dried root of Scutellaria baicalensis georgi, has been shown to effectively inhibit cell apoptosis. Therefore, we assumed that baicalin would suppress colistin sulfate-induced neuronal apoptosis. PC12 cells exposed to colistin sulfate （62.5-500 μg/mL） for 24 hours resulted in PCl2 cell apoptosis. In addition, caspase-3 activity, lactate dehydrogenase level and free radical content increased in a dose-dependent manner. Subsequently, PC12 cells were pretreated with baicalin （25, 50 and 100 pg/mL）, and exposed to 125 pg/mL colistin sulfate. Cell morphology markedly changed, and cell viability increased. Moreover, caspase-3 activity, lac- tate dehydrogenase level and free radical content decreased. Results indicated that baicalin inhib- ited colistin sulfate-induced PC12 cell apoptosis by suppressing free radical injury, and reducing caspase-3 activity and lactate dehydrogenase activity.展开更多
BACKGROUND： Substantia nigra is deep in position and limited in range, the glial cell line-derived neurotrophic factor （GDNF） injection directly into substantia nigra has relatively greater damages with higher diff...BACKGROUND： Substantia nigra is deep in position and limited in range, the glial cell line-derived neurotrophic factor （GDNF） injection directly into substantia nigra has relatively greater damages with higher difficulty. GDNF injection into striatum, the target area of dopaminergic neuron, may protect the dopaminergic neurons in the compact part of substantia nigra through retrograde transport. OBJECTIVE： To investigate the protective effect of intrastriatal GDNF on dopaminergic neurons in the substantia nigra of mice with Parkinson disease （PD）, and analyze the action pathway. DESIGN： A controlled observation. SETTING： Neurobiological Laboratory of Xuzhou Medical College. MATERIALS： Twenty-four male Kunming mice of 7 - 8 weeks old were used. GDNF, 1-methy1-4-pheny1-1,2,3,6-tetrahydropyridine （MPTP） were purchased from Sigma Company （USA）; LEICAQWin image processing and analytical system. METHODS： The experiments were carded out in the Neurobiological Laboratory of Xuzhou Medical College from September 2005 to October 2006. The PD models were established in adult KunMing mice by intraperitoneal injection of MPTP. The model mice were were randomly divided into four groups with 6 mice in each group： GDNF 4-day group, phosphate buffer solution （PSB） 4-day group, GDNF 6-day group and PSB 6-day group. Mice in the GDNF 4 and 6-day groups were administrated with 1 μ L GDNF solution （20 μ g/L, dispensed with 0.01 mol/L PBS） injected into right striatum at 4 and 6 days after model establishment. Mice in the PSB 4 and 6-day groups were administrated with 0.01 mol/L PBS of the same volume to the same injection at corresponding time points. ② On the 12^th day after model establishment, the midbrain tissue section of each mice was divided into 3 areas from rostral to caudal sides. The positive neurons of tyroxine hydroxylase （TH） and calcium binding protein （CB） with obvious nucleolus and clear outline were randomly selected for the measurement, and the number of positive neurons in unit area was counted. MAIN OUTCOME MEASURES： Number of positive neurons of TH and CB in midbrain substantia nigra of mice in each group. RESULTS： All the 24 mice were involved in the analysis of results. The numbers of TH^＋ and CB^＋ neurons in the GDNF 4-day group （54.33±6.92, 46.33±5.54） were obviously more than those in the PBS 4-day group （27.67±5.01, 21.50±5.96, P 〈 0.01）. The numbers of TH^＋ and CB^＋ neurons in the GDNF 6-day group （75.67±5.39, 69.67±8.69） were obviously more than those in the PBS 6-day group （27.17±4.50, 21.33 ±5.72, P 〈 0.01） and those in the GDNF 4-day group （P 〈 0.01 ）. CONCLUSION： Intrastriatal GDNF can protect dopaminergic neurons in substantia nigra of PD mice, and it may be related to the increase of CB expression.展开更多
Graphite-like carbon nitride （g-C3N4） was synthesized in large quantities at 300 ℃ under nitrogen by a solidstate reaction route. Furthermore, Al3＋ and Mg2＋ intercalation of g-CaN4 was performed by an electrochem...Graphite-like carbon nitride （g-C3N4） was synthesized in large quantities at 300 ℃ under nitrogen by a solidstate reaction route. Furthermore, Al3＋ and Mg2＋ intercalation of g-CaN4 was performed by an electrochemical method. The starting C3N4 materials and intercalation compounds were characterized by X-ray powder diffraction, Fourier transform infrared spectra, thermogravimetry, transmission electron microscopy, and X-ray photoelectron spectroscopy. The possible structure model of intercalation compounds was proposed. The cation-π interactions and electrostatic interactions were used to explain the changes of microstructure and chemical bonds before and after intercalation.展开更多
[ Objectlve] This study aimed to investigate the antimicrobial effect of Chinese herbal preparation Yinqiaotiangan against Streptococcus suis serotype II in vivo. [ Method ] The prevention and treatment tests were con...[ Objectlve] This study aimed to investigate the antimicrobial effect of Chinese herbal preparation Yinqiaotiangan against Streptococcus suis serotype II in vivo. [ Method ] The prevention and treatment tests were conducted with Kunming mice weighing about 18 -22 g. In the prevention test, Kunming mice were inocu- lated with Streptococcus suis serotype II and simultaneously taken orally 0.5, 1.0 and 2.0 g/ml Chinese herbal preparation Yinqiaotiangan respectively for continu- ous 3 d, once a day; the incidence rate, mortality rate and protective rate were detected after 7 d. In the treatment test, Kunming mice were inoculated with Strepto- coccus suis serotype II to establish the Streptococcus suis serotype II pathogenic model, and then taken orally 0.5, 1.0 and 2.0 g/ml Chinese herbal preparation Yin- qiaotiangan respectively for continuous 3 d, twice a day; the mortality rate, cure rate and effective rate were detected after 7 d. [ Result ] Results of the prevention test showed that the protective rate in experimental groups was extremely significantly higher than that in control group （P 〈0.01 ）, while the incidence rate and mortality rate were extremely significantly lower than that in control group （P 〈0.01 ）. Results of the treatment test showed that the incidence rate in experimental groups was extremely significantly lower than that in control group （P 〈0.01 ）, the cure rate in 0.5 g/ml group was extremely significantly higher than that in 1.0 g/ml group and 2.0 g/ml group （P 〈 0.01 ）, the effective rate in 0.5 g/ml group was significantly higher than that in 1.0 g/ml group and 2.0 g/ml group （ P 〈 0.05 ）, with no significant difference from the positive group （P 〉 0.05 ）. [ Conclusion ] The pathologic model of Streptococcus su/s serotype II could be effec- tively prevented and treated by oral intake of low dose of Chinese herbal preparation Yinqiaotiangan in Kunming mice.展开更多
In recent years,high-end equipment is widely used in industry and the accuracy requirements of the equipment have been risen year by year.During the machining process,the high-end equipment failure may have a great im...In recent years,high-end equipment is widely used in industry and the accuracy requirements of the equipment have been risen year by year.During the machining process,the high-end equipment failure may have a great impact on the product quality.It is necessary to monitor the status of equipment and to predict fault diagnosis.At present,most of the condition monitoring devices for mechanical equipment have problems of large size,low precision and low energy utilization.A wireless self-powered intelligent spindle vibration acceleration sensor system based on piezoelectric energy harvesting is proposed.Based on rotor sensing technology,a sensor is made to mount on the tool holder and build the related circuit.Firstly,the energy management module collects the mechanical energy in the environment and converts the piezoelectric vibration energy into electric energy to provide 3.3 Vfor the subsequent circuit.The lithium battery supplies the system with additional power and monitors’the power of the energy storage circuit in real-time.Secondly,a three-axis acceleration sensor is used to collect,analyze and filter a series of signal processing operations of the vibration signal in the environment.The signal is sent to the upper computer by wireless transmission.The host computer outputs the corresponding X,Y,and Z channel waveforms and data under the condition of the spindle speed of 50∼2500 r/min with real-time monitoring.The KEIL5 platform is used to develop the system software.The small-size piezoelectric vibration sensor with high-speed,high-energy utilization,high accuracy,and easy installation is used for spindle monitoring.The experiment results show that the sensor system is available and practical.展开更多
The Heck coupling reactions of aryl halides and olefins were performed under the microwave assistance. Interestingly, the ultralow concentration of transition metals (in ppb) coming from the reactants could catalyze t...The Heck coupling reactions of aryl halides and olefins were performed under the microwave assistance. Interestingly, the ultralow concentration of transition metals (in ppb) coming from the reactants could catalyze the Heck coupling reactions under microwave irradiation, without addition of any catalysts, ligands and phase-transfer agents. The influences of bases, solvents and temperature were discussed, and the reaction rate was enhanced largely in the mixed solvents of NMP and water due to the solubility of base in water.展开更多
Transparent nanostructured BaTiO3 film electrodes were synthesized on conductive substrates from BaTiO3 nanocrystals forming at low temperature. Electrochemical and spectroelectrochemical methods were employed to inve...Transparent nanostructured BaTiO3 film electrodes were synthesized on conductive substrates from BaTiO3 nanocrystals forming at low temperature. Electrochemical and spectroelectrochemical methods were employed to investigate its properties of band energetics and the trap state at different pH values. The flat band edges greatly depended on the pH value of electrolyte, and the flat band edges were -0.70, -0.92 and -1.20 V vs saturated Ag/AgCl at the pH value of 3.0, 6.8 and 13.0, respectively. The results showed that trap state densities also highly depended on pH. The total trap state densities were 3.73 × 1015, 4.02 × 1015 and 6.48 × 1016 cm-2 at pH value of 3.0, 6.8 and 13.0 respectively with maximum located at -0.36 V, -0.50 V and -0.80 V. The results obtained from CVs were in good agreement with that obtained from the measurements of time resolved currents. The size of the peak potentials in the cyclic voltammograms experiments was increased dramatically with the pH value increasing, indicating that traps were surface-related.展开更多
Chronic pancreatitis is best described as a relentless, continuous inflammatory destruction of the pancreas parenchyma, characterized by irreversible destruction of the exocrine tissues, fibrosis, and at the late stag...Chronic pancreatitis is best described as a relentless, continuous inflammatory destruction of the pancreas parenchyma, characterized by irreversible destruction of the exocrine tissues, fibrosis, and at the late stage, the destruction of endocrine cells. Current therapies for chronic pancreatitis patients focus on pain relief by medical and minimally invasive endoscopic treatment as well as surgical management with resection of diseased parenchyma and drainage of obstructed ducts. Radical treatment of chronic pancreatitis has been successful with total pancreatictomy and islet autotransplantation (TP-IAT) that may prevent maladaptive intractable pain pathways and also avoid pancreatogenic diabetes in the well-selected patient. Distinct loss of pancreatic islet cells occurs in about 30%-50% of patients during the progression of chronic pancreatitis when severe fibrosis develops at the late stage of the disease. Profound β cell apoptosis induced by stresses encountered during islet isolation and transplantation further compromises β cell survival and function after TP-IAT. The molecular mechanisms that lead to β cell dysfunction in chronic pancreatitis remain largely undelineated. In this review, we summarize factors that may contribute β cell apoptosis during the disease progress and after TP-IAT and discuss potential interventional approaches that may prevent islet cell death during these processes. Such information is critical to the development of therapeutic protocols that can preserve the viability and function of β cell in patients with chronic pancreatitis.展开更多
At present,the incidence rate of arteriosclerosis obliterans(LEASO)of the lower extremities is significantly increased by aging and lifestyle changes.It is of great importance to predict the LEASO effectively and accu...At present,the incidence rate of arteriosclerosis obliterans(LEASO)of the lower extremities is significantly increased by aging and lifestyle changes.It is of great importance to predict the LEASO effectively and accurately by analyzing the imaging data of the lower extremities⑴.At this stage,China has entered the era of big data and artificial intelligence.Medical institutions at all levels can produce a large number of lower limb vascular image data every day.Using big data deep learning technology to intelligently analyze a large number of image data,and then carry out auxiliary diagnosis,so as to improve the diagnosis and treatment effect of LEASO is the focus of clinical research.展开更多
Chronic hepatitis B(CHB)is a significant global health issue,affecting millions of people worldwide and leading to serious complications such as cirrhosis and hepatocellular carcinoma.The current standard treatments f...Chronic hepatitis B(CHB)is a significant global health issue,affecting millions of people worldwide and leading to serious complications such as cirrhosis and hepatocellular carcinoma.The current standard treatments for CHB,including nucleos(t)ide analogs(NAs)and interferon therapy,have limitations,such as the need for long-term administration and the potential for drug resistance.展开更多
The fields of tissue engineering and regenerative medicine have made astounding progress in recent years,evidenced by cutting-edge 4D printing technologies,precise gene editing tools,and sustained long-term functional...The fields of tissue engineering and regenerative medicine have made astounding progress in recent years,evidenced by cutting-edge 4D printing technologies,precise gene editing tools,and sustained long-term functionality of engineered tissue grafts.Despite these fantastic feats,the clinical success of tissue-engineered constructs so far remains limited to only those relatively simple types of tissues such as thin bilayer skin equivalents or avascular cartilage.On the other hand,volumetric tissues(larger than a few millimeters in all dimensions),which are highly desirable for clinical utility,suffer from poor oxygen supply due to limited dimensional diffusion.Notably,large,complex tissues typically require a vascular network to supply the growing cells with nutrients for metabolic demands to prolong viability and support tissue formation.In recognition,extensive efforts have been made to create vascular-like networks in order to facilitate mass exchange through volumetric scaffolds.This review underlines the urgent need for continued research to create more complex and functional vascular networks,which is crucial for generating viable volumetric tissues,and highlights the recent advances in sacrificial template-enabled formation of vascular-like networks.展开更多
In the unstructured litchi orchard,precise identification and localization of litchi fruits and picking points are crucial for litchi-picking robots.Most studies adopt multi-step methods to detect fruit and locate pic...In the unstructured litchi orchard,precise identification and localization of litchi fruits and picking points are crucial for litchi-picking robots.Most studies adopt multi-step methods to detect fruit and locate picking points,which are slow and struggle to cope with complex environments.This study proposes a YOLOv8-iGR model based on YOLOv8n-pose improvement,integrating end-to-end network for both object detection and key point detection.Specifically,this study considers the influence of auxiliary points on picking point and designs four litchi key point strategies.Secondly,the architecture named iSaE is proposed,which combines the capabilities of CNN and attention mechanism.Subsequently,C2f is replaced by Generalized Efficient Layer Aggregation Network(GELAN)to reduce model redundancy and improve detection accuracy.Finally,based on RFAConv,RFAPoseHead is designed to address the issue of parameter sharing in large convolutional kernels,thereby more effectively extracting feature information.Experimental results demonstrate that YOLOv8-iGR achieves an AP of 95.7%in litchi fruit detection,and the Euclidean distance error of picking points is less than 8 pixels across different scenes,meeting the requirements of litchi picking.Additionally,the GFLOPs of the model are reduced by 10.71%.The accuracy of the model’s localization for picking points was tested through field picking experiments.In conclusion,YOLOv8-iGR exhibits outstanding detection performance along with lower model complexity,making it more feasible for implementation on robots.This will provide technical support for the vision system of the litchi-picking robot.展开更多
Global cooling began since 50 Ma,but a warm climate was maintained in the archipelagic tectonic system in Southeast Asia where a wealth of Cenozoic oil and gas resources was formed and preserved.From the perspective o...Global cooling began since 50 Ma,but a warm climate was maintained in the archipelagic tectonic system in Southeast Asia where a wealth of Cenozoic oil and gas resources was formed and preserved.From the perspective of Earth system,this study analyzes Cenozoic tectonic activities,climatic and environmental evolution,and petroleum enrichment in Southeast Asia,and provides the following insights:(1)Subduction of oceanic plates and the extension of overlying continental lithosphere resulted in widespread volcanic eruptions as well as the formation of rift basins and shallow marine shelves,leading to complex interactions between deep tectonic processes and Earth’s surface including mountains,basins,and seas.(2)Microcontinental accretion and prolonged stay in equatorial low-latitude regions have changed trade winds into monsoons,altered ocean current pathways and flow rates,and profoundly affected rainfall and climate.(3)The archipelagic tectonic system,coupled with a hot and rainy climate,fostered tropical rainforests,mangroves,and phytoplankton,providing abundant organic matter and promoting the development of petroleum resources.(4)Combinations of rift basin development and marine transgression and regression led to an effective superposition of source-reservoir-seal combinations from multiplepetroleum systems.Rapid deep burial of organic matter and high geothermal gradients facilitated the generation and large-scale accumulation of oil and gas.(5)Multi-spherical(such as atmosphere,biosphere,hydrosphere and lithosphere)interactions on the Earth,which resulted from the convergence of multiple tectonic plates,are believed as the primary driver for exceptional enrichments of Cenozoic oil and gas resources in Southeast Asia.These understandings are significant for developing theories of oil and gas enrichment under the guidance of Earth System Science.In order to continue making significant oil and gas exploration discoveries in the deep-layers,deep-waters,and unconventional oil and gas fields of Southeast Asia,attention should be paid to the oil and gas resource effects of the collision between Australia and Sunda blocks and the high-temperature and high-rainfall climate environment,and efforts should be made to develop economic development and CO_(2)sequestration technologies for offshore CO_(2)-rich gas fields.展开更多
Osteoarthritis(OA)is an aging-associated disease characterized by joint stiffness pain and destroyed articular cartilage.Traditional treatments for OA are limited to alleviating various OA symptoms.There is a lack of ...Osteoarthritis(OA)is an aging-associated disease characterized by joint stiffness pain and destroyed articular cartilage.Traditional treatments for OA are limited to alleviating various OA symptoms.There is a lack of drugs available in clinical practice that can truly repair cartilage damage.Here,we developed the chondroitin sulfate analog CS-semi5,semi-synthesized from chondroitin sulfate A.In vivo,CS-semi5 alleviated inflammation,provided analgesic effects,and protected cartilage in the modified Hulth OA rat model and papain-induced OA rat model.A bioinformatics analysis was performed on samples from OA patients and an exosome analysis on papain-induced OA rats,revealing miR-122-5p as the key regulator associated with CS-semi5 in OA treatment.Binding prediction revealed that miR-122-5p acted on the 30-untranslated region of p38 mitogen-activated protein kinase,which was related to MMP13 regulation.Subsequent in vitro experiments revealed that CS-semi5 effectively reduced cartilage degeneration and maintained matrix homeostasis by inhibiting matrix breakdown through the miR-122-5p/p38/MMP13 axis,which was further validated in the articular cartilage of OA rats.This is the first study to investigate the semi-synthesized chondroitin sulfate CS-semi5,revealing its cartilageprotecting,anti-inflammatory,and analgesic properties that show promising therapeutic effects in OA via the miR-122-5p/p38/MMP13 pathway.展开更多
Recent achievements in deep learning(DL)have demonstrated its potential in predicting traffic flows.Such predictions are beneficial for understanding the situation and making traffic control decisions.However,most sta...Recent achievements in deep learning(DL)have demonstrated its potential in predicting traffic flows.Such predictions are beneficial for understanding the situation and making traffic control decisions.However,most state-of-the-art DL models are consi-dered“black boxes”with little to no transparency of the underlying mechanisms for end users.Some previous studies attempted to“open the black box”and increase the interpretability of generated predictions.However,handling complex models on large-scale spatiotemporal data and discovering salient spatial and temporal patterns that significantly influence traffic flow remain challenging.To overcome these challenges,we present TrafPS,a visual analytics approach for interpreting traffic prediction outcomes to support decision-making in traffic management and urban planning.The measurements region SHAP and trajectory SHAP are proposed to quantify the impact of flow patterns on urban traffic at different levels.Based on the task requirements from domain experts,we employed an interactive visual interface for the multi-aspect exploration and analysis of significant flow patterns.Two real-world case studies demonstrate the effectiveness of TrafPS in identifying key routes and providing decision-making support for urban planning.展开更多
基金funded by PetroChina projects(No.2021DJ3102,No.2021DJ3301).
文摘The right bank of the Amu Darya Basin enjoys abundant natural gas resources,on which the Callovian-Oxfordian strata in the middle of Block B serve as the major horizons for natural gas production.However,the characteristics and distribution patterns of the sedimentary microfacies in these strata are yet to be further explored.Based on the analysis of data on drilling,logging,cores,and thin sections from 29 typical wells,as well as the regional sedimentary background,this study inferred that the middle of Block B evolved from the Callovian ramp platform into the Oxfordian rimmed platform.Moreover,this study determined that the inner-ramp intertidal-subtidal shallow-water subfacies mainly developed during the Callovian and transitioned into the shallow shelf subfacies during the Oxfordian.This study identified eight sedimentary microfacies,namely reef knoll,reef-shoal complex,bioclastic shoal,psammitic shoal,bioherm,lime mud mound,intershoal(intermound),and static-water mud.Based on research into the high-precision sequence-sedimentary microfacies framework,this study built a geological model for the development of sedimentary microfacies in the study area.According to this geological model,the sedimentary microfacies in the study area are characterized by vertical alternation of reef-shoal complex,bioclastic(psammitic)shoal,bioherm,and intershoal microfacies.Moreover,they show the development of reef knoll,reef-shoal complex,bioclastic(psammitic)shoal,and bioherm(or lime mud mound)laterally from west to east,with the physical properties of the reservoirs deteriorating from west to east accordingly.The microfacies of reef-shoal complex and the bioclastic(psammitic)shoal predominate in the study area,and their deposition and development are controlled by sequence boundaries and are also affected by paleo-landforms.The Oxfordian reef-shoal complexes were largely inherited from the Callovian uplifts and show lateral seaward progradation.
文摘The dual-rotor structure serves as the primary source of vibration in aero-engines. Understanding itsdynamical model and analyzing dynamic characteristics, such as critical speed and unbalanced response, arecrucial for rotor system dynamics. Previous work introduced a coaxial dual-rotor-support scheme for aeroengines,and a physical model featuring a high-speed flexible inner rotor with a substantial length-to-diameter ratiowas designed. Then a finite element (FE) dynamic model based on the Timoshenko beam elements and rigid bodykinematics of the dual-rotor system is modeled, with the Newmark method and Newton–Raphson method used forthe numerical calculation to study the dynamic characteristics of the system. Three different simulation models,including beam-based FE (1D) model, solid-based FE (3D) model, and transfer matrix model, were designed tostudy the characteristics of mode and the critical speed characteristic of the dual-rotor system. The unbalancedresponse of the dual-rotor system was analyzed to study the influence of mass unbalance on the rotor system. Theeffect of different disk unbalance phases and different speed ratios on the dynamic characteristics of the dual-rotorsystem was investigated in detail. The experimental result shows that the beam-based FE model is effective andsuitable for studying the dual-rotor system.
基金supported by the National Natural Science Foundation of China,No.31201951 and 31272613the Scientific and Technological Innovation Talent Scientific Research Foundation for the Returned Overseas Chinese Scholars by State Education Ministry and Heilongjiang Province in China,No.2012RFLXN005 and LC201018+1 种基金the Youth Science and Technology Foundation of Liaoning Medical University in China,No.Y2012Z023the Science and Technology Department of Liaoning Provincial Foundation Programs,No.2011214001
文摘Baicalin, a type of flavonoid extracted from the dried root of Scutellaria baicalensis georgi, has been shown to effectively inhibit cell apoptosis. Therefore, we assumed that baicalin would suppress colistin sulfate-induced neuronal apoptosis. PC12 cells exposed to colistin sulfate （62.5-500 μg/mL） for 24 hours resulted in PCl2 cell apoptosis. In addition, caspase-3 activity, lactate dehydrogenase level and free radical content increased in a dose-dependent manner. Subsequently, PC12 cells were pretreated with baicalin （25, 50 and 100 pg/mL）, and exposed to 125 pg/mL colistin sulfate. Cell morphology markedly changed, and cell viability increased. Moreover, caspase-3 activity, lac- tate dehydrogenase level and free radical content decreased. Results indicated that baicalin inhib- ited colistin sulfate-induced PC12 cell apoptosis by suppressing free radical injury, and reducing caspase-3 activity and lactate dehydrogenase activity.
基金the Natural Science Foundation of Jiangsu Department of Education, No. 02KJB310009
文摘BACKGROUND： Substantia nigra is deep in position and limited in range, the glial cell line-derived neurotrophic factor （GDNF） injection directly into substantia nigra has relatively greater damages with higher difficulty. GDNF injection into striatum, the target area of dopaminergic neuron, may protect the dopaminergic neurons in the compact part of substantia nigra through retrograde transport. OBJECTIVE： To investigate the protective effect of intrastriatal GDNF on dopaminergic neurons in the substantia nigra of mice with Parkinson disease （PD）, and analyze the action pathway. DESIGN： A controlled observation. SETTING： Neurobiological Laboratory of Xuzhou Medical College. MATERIALS： Twenty-four male Kunming mice of 7 - 8 weeks old were used. GDNF, 1-methy1-4-pheny1-1,2,3,6-tetrahydropyridine （MPTP） were purchased from Sigma Company （USA）; LEICAQWin image processing and analytical system. METHODS： The experiments were carded out in the Neurobiological Laboratory of Xuzhou Medical College from September 2005 to October 2006. The PD models were established in adult KunMing mice by intraperitoneal injection of MPTP. The model mice were were randomly divided into four groups with 6 mice in each group： GDNF 4-day group, phosphate buffer solution （PSB） 4-day group, GDNF 6-day group and PSB 6-day group. Mice in the GDNF 4 and 6-day groups were administrated with 1 μ L GDNF solution （20 μ g/L, dispensed with 0.01 mol/L PBS） injected into right striatum at 4 and 6 days after model establishment. Mice in the PSB 4 and 6-day groups were administrated with 0.01 mol/L PBS of the same volume to the same injection at corresponding time points. ② On the 12^th day after model establishment, the midbrain tissue section of each mice was divided into 3 areas from rostral to caudal sides. The positive neurons of tyroxine hydroxylase （TH） and calcium binding protein （CB） with obvious nucleolus and clear outline were randomly selected for the measurement, and the number of positive neurons in unit area was counted. MAIN OUTCOME MEASURES： Number of positive neurons of TH and CB in midbrain substantia nigra of mice in each group. RESULTS： All the 24 mice were involved in the analysis of results. The numbers of TH^＋ and CB^＋ neurons in the GDNF 4-day group （54.33±6.92, 46.33±5.54） were obviously more than those in the PBS 4-day group （27.67±5.01, 21.50±5.96, P 〈 0.01）. The numbers of TH^＋ and CB^＋ neurons in the GDNF 6-day group （75.67±5.39, 69.67±8.69） were obviously more than those in the PBS 6-day group （27.17±4.50, 21.33 ±5.72, P 〈 0.01） and those in the GDNF 4-day group （P 〈 0.01 ）. CONCLUSION： Intrastriatal GDNF can protect dopaminergic neurons in substantia nigra of PD mice, and it may be related to the increase of CB expression.
基金supported by the shandong Science and Technology Council,China (No. BS2010CL013)
文摘Graphite-like carbon nitride （g-C3N4） was synthesized in large quantities at 300 ℃ under nitrogen by a solidstate reaction route. Furthermore, Al3＋ and Mg2＋ intercalation of g-CaN4 was performed by an electrochemical method. The starting C3N4 materials and intercalation compounds were characterized by X-ray powder diffraction, Fourier transform infrared spectra, thermogravimetry, transmission electron microscopy, and X-ray photoelectron spectroscopy. The possible structure model of intercalation compounds was proposed. The cation-π interactions and electrostatic interactions were used to explain the changes of microstructure and chemical bonds before and after intercalation.
基金Supported by Youth Science and Technology Start-up Fund of Liaoning Medical University(Y2012Z023)Project of Agricultural Science and Technology Achievement Transformation from the Ministry of Science and Technology of China(2012GB2B000097)
文摘[ Objectlve] This study aimed to investigate the antimicrobial effect of Chinese herbal preparation Yinqiaotiangan against Streptococcus suis serotype II in vivo. [ Method ] The prevention and treatment tests were conducted with Kunming mice weighing about 18 -22 g. In the prevention test, Kunming mice were inocu- lated with Streptococcus suis serotype II and simultaneously taken orally 0.5, 1.0 and 2.0 g/ml Chinese herbal preparation Yinqiaotiangan respectively for continu- ous 3 d, once a day; the incidence rate, mortality rate and protective rate were detected after 7 d. In the treatment test, Kunming mice were inoculated with Strepto- coccus suis serotype II to establish the Streptococcus suis serotype II pathogenic model, and then taken orally 0.5, 1.0 and 2.0 g/ml Chinese herbal preparation Yin- qiaotiangan respectively for continuous 3 d, twice a day; the mortality rate, cure rate and effective rate were detected after 7 d. [ Result ] Results of the prevention test showed that the protective rate in experimental groups was extremely significantly higher than that in control group （P 〈0.01 ）, while the incidence rate and mortality rate were extremely significantly lower than that in control group （P 〈0.01 ）. Results of the treatment test showed that the incidence rate in experimental groups was extremely significantly lower than that in control group （P 〈0.01 ）, the cure rate in 0.5 g/ml group was extremely significantly higher than that in 1.0 g/ml group and 2.0 g/ml group （P 〈 0.01 ）, the effective rate in 0.5 g/ml group was significantly higher than that in 1.0 g/ml group and 2.0 g/ml group （ P 〈 0.05 ）, with no significant difference from the positive group （P 〉 0.05 ）. [ Conclusion ] The pathologic model of Streptococcus su/s serotype II could be effec- tively prevented and treated by oral intake of low dose of Chinese herbal preparation Yinqiaotiangan in Kunming mice.
基金supported by the National Natural Science Foundation of China(51975058).
文摘In recent years,high-end equipment is widely used in industry and the accuracy requirements of the equipment have been risen year by year.During the machining process,the high-end equipment failure may have a great impact on the product quality.It is necessary to monitor the status of equipment and to predict fault diagnosis.At present,most of the condition monitoring devices for mechanical equipment have problems of large size,low precision and low energy utilization.A wireless self-powered intelligent spindle vibration acceleration sensor system based on piezoelectric energy harvesting is proposed.Based on rotor sensing technology,a sensor is made to mount on the tool holder and build the related circuit.Firstly,the energy management module collects the mechanical energy in the environment and converts the piezoelectric vibration energy into electric energy to provide 3.3 Vfor the subsequent circuit.The lithium battery supplies the system with additional power and monitors’the power of the energy storage circuit in real-time.Secondly,a three-axis acceleration sensor is used to collect,analyze and filter a series of signal processing operations of the vibration signal in the environment.The signal is sent to the upper computer by wireless transmission.The host computer outputs the corresponding X,Y,and Z channel waveforms and data under the condition of the spindle speed of 50∼2500 r/min with real-time monitoring.The KEIL5 platform is used to develop the system software.The small-size piezoelectric vibration sensor with high-speed,high-energy utilization,high accuracy,and easy installation is used for spindle monitoring.The experiment results show that the sensor system is available and practical.
文摘The Heck coupling reactions of aryl halides and olefins were performed under the microwave assistance. Interestingly, the ultralow concentration of transition metals (in ppb) coming from the reactants could catalyze the Heck coupling reactions under microwave irradiation, without addition of any catalysts, ligands and phase-transfer agents. The influences of bases, solvents and temperature were discussed, and the reaction rate was enhanced largely in the mixed solvents of NMP and water due to the solubility of base in water.
文摘Transparent nanostructured BaTiO3 film electrodes were synthesized on conductive substrates from BaTiO3 nanocrystals forming at low temperature. Electrochemical and spectroelectrochemical methods were employed to investigate its properties of band energetics and the trap state at different pH values. The flat band edges greatly depended on the pH value of electrolyte, and the flat band edges were -0.70, -0.92 and -1.20 V vs saturated Ag/AgCl at the pH value of 3.0, 6.8 and 13.0, respectively. The results showed that trap state densities also highly depended on pH. The total trap state densities were 3.73 × 1015, 4.02 × 1015 and 6.48 × 1016 cm-2 at pH value of 3.0, 6.8 and 13.0 respectively with maximum located at -0.36 V, -0.50 V and -0.80 V. The results obtained from CVs were in good agreement with that obtained from the measurements of time resolved currents. The size of the peak potentials in the cyclic voltammograms experiments was increased dramatically with the pH value increasing, indicating that traps were surface-related.
文摘Chronic pancreatitis is best described as a relentless, continuous inflammatory destruction of the pancreas parenchyma, characterized by irreversible destruction of the exocrine tissues, fibrosis, and at the late stage, the destruction of endocrine cells. Current therapies for chronic pancreatitis patients focus on pain relief by medical and minimally invasive endoscopic treatment as well as surgical management with resection of diseased parenchyma and drainage of obstructed ducts. Radical treatment of chronic pancreatitis has been successful with total pancreatictomy and islet autotransplantation (TP-IAT) that may prevent maladaptive intractable pain pathways and also avoid pancreatogenic diabetes in the well-selected patient. Distinct loss of pancreatic islet cells occurs in about 30%-50% of patients during the progression of chronic pancreatitis when severe fibrosis develops at the late stage of the disease. Profound β cell apoptosis induced by stresses encountered during islet isolation and transplantation further compromises β cell survival and function after TP-IAT. The molecular mechanisms that lead to β cell dysfunction in chronic pancreatitis remain largely undelineated. In this review, we summarize factors that may contribute β cell apoptosis during the disease progress and after TP-IAT and discuss potential interventional approaches that may prevent islet cell death during these processes. Such information is critical to the development of therapeutic protocols that can preserve the viability and function of β cell in patients with chronic pancreatitis.
基金Scientific research project of Sichuan Provincial Health Commission"auxiliary diagnosis of lower extremity arteriosclerosis obliterans based on deep learning of big data,"No.:18PJ488.
文摘At present,the incidence rate of arteriosclerosis obliterans(LEASO)of the lower extremities is significantly increased by aging and lifestyle changes.It is of great importance to predict the LEASO effectively and accurately by analyzing the imaging data of the lower extremities⑴.At this stage,China has entered the era of big data and artificial intelligence.Medical institutions at all levels can produce a large number of lower limb vascular image data every day.Using big data deep learning technology to intelligently analyze a large number of image data,and then carry out auxiliary diagnosis,so as to improve the diagnosis and treatment effect of LEASO is the focus of clinical research.
基金supported by grants from the National Key R&D Program of China(2019YFA0905903 to M.Z.and 2022YFC2304104 toW.W.)the National Natural Science Foun-dation of China(81991493 to Q.C.)the Beijing Municipal Science&Technology Commission(L232008 to M.Z.).
文摘Chronic hepatitis B(CHB)is a significant global health issue,affecting millions of people worldwide and leading to serious complications such as cirrhosis and hepatocellular carcinoma.The current standard treatments for CHB,including nucleos(t)ide analogs(NAs)and interferon therapy,have limitations,such as the need for long-term administration and the potential for drug resistance.
基金National ScienceFoundation,Grant/Award Number:NSF-GCR award number 2219014U.S.Army Medical Research and Development Command,Grant/Award Number:W81XWH2211044Established Investigator Grant award from MTF Biologics。
文摘The fields of tissue engineering and regenerative medicine have made astounding progress in recent years,evidenced by cutting-edge 4D printing technologies,precise gene editing tools,and sustained long-term functionality of engineered tissue grafts.Despite these fantastic feats,the clinical success of tissue-engineered constructs so far remains limited to only those relatively simple types of tissues such as thin bilayer skin equivalents or avascular cartilage.On the other hand,volumetric tissues(larger than a few millimeters in all dimensions),which are highly desirable for clinical utility,suffer from poor oxygen supply due to limited dimensional diffusion.Notably,large,complex tissues typically require a vascular network to supply the growing cells with nutrients for metabolic demands to prolong viability and support tissue formation.In recognition,extensive efforts have been made to create vascular-like networks in order to facilitate mass exchange through volumetric scaffolds.This review underlines the urgent need for continued research to create more complex and functional vascular networks,which is crucial for generating viable volumetric tissues,and highlights the recent advances in sacrificial template-enabled formation of vascular-like networks.
基金supported by Natural Science Foundation of Guangdong Province(Grant No.2025A1515011771)Guangzhou Science and Technology Plan Project(Grant No.2024E04J1242,2023B01J0046)+2 种基金Guangdong Provincial Department of Science and Technology(Grant No.2023A0505050130)Key Projects of Guangzhou Science and Technology Program(Grant No.2024B03J1357)Natural Science Foundation of China(Grant No.61863011,32071912).
文摘In the unstructured litchi orchard,precise identification and localization of litchi fruits and picking points are crucial for litchi-picking robots.Most studies adopt multi-step methods to detect fruit and locate picking points,which are slow and struggle to cope with complex environments.This study proposes a YOLOv8-iGR model based on YOLOv8n-pose improvement,integrating end-to-end network for both object detection and key point detection.Specifically,this study considers the influence of auxiliary points on picking point and designs four litchi key point strategies.Secondly,the architecture named iSaE is proposed,which combines the capabilities of CNN and attention mechanism.Subsequently,C2f is replaced by Generalized Efficient Layer Aggregation Network(GELAN)to reduce model redundancy and improve detection accuracy.Finally,based on RFAConv,RFAPoseHead is designed to address the issue of parameter sharing in large convolutional kernels,thereby more effectively extracting feature information.Experimental results demonstrate that YOLOv8-iGR achieves an AP of 95.7%in litchi fruit detection,and the Euclidean distance error of picking points is less than 8 pixels across different scenes,meeting the requirements of litchi picking.Additionally,the GFLOPs of the model are reduced by 10.71%.The accuracy of the model’s localization for picking points was tested through field picking experiments.In conclusion,YOLOv8-iGR exhibits outstanding detection performance along with lower model complexity,making it more feasible for implementation on robots.This will provide technical support for the vision system of the litchi-picking robot.
基金supported by the National Natural Science Foundation of China(Grant Nos.42288201,92255303,42202162)。
文摘Global cooling began since 50 Ma,but a warm climate was maintained in the archipelagic tectonic system in Southeast Asia where a wealth of Cenozoic oil and gas resources was formed and preserved.From the perspective of Earth system,this study analyzes Cenozoic tectonic activities,climatic and environmental evolution,and petroleum enrichment in Southeast Asia,and provides the following insights:(1)Subduction of oceanic plates and the extension of overlying continental lithosphere resulted in widespread volcanic eruptions as well as the formation of rift basins and shallow marine shelves,leading to complex interactions between deep tectonic processes and Earth’s surface including mountains,basins,and seas.(2)Microcontinental accretion and prolonged stay in equatorial low-latitude regions have changed trade winds into monsoons,altered ocean current pathways and flow rates,and profoundly affected rainfall and climate.(3)The archipelagic tectonic system,coupled with a hot and rainy climate,fostered tropical rainforests,mangroves,and phytoplankton,providing abundant organic matter and promoting the development of petroleum resources.(4)Combinations of rift basin development and marine transgression and regression led to an effective superposition of source-reservoir-seal combinations from multiplepetroleum systems.Rapid deep burial of organic matter and high geothermal gradients facilitated the generation and large-scale accumulation of oil and gas.(5)Multi-spherical(such as atmosphere,biosphere,hydrosphere and lithosphere)interactions on the Earth,which resulted from the convergence of multiple tectonic plates,are believed as the primary driver for exceptional enrichments of Cenozoic oil and gas resources in Southeast Asia.These understandings are significant for developing theories of oil and gas enrichment under the guidance of Earth System Science.In order to continue making significant oil and gas exploration discoveries in the deep-layers,deep-waters,and unconventional oil and gas fields of Southeast Asia,attention should be paid to the oil and gas resource effects of the collision between Australia and Sunda blocks and the high-temperature and high-rainfall climate environment,and efforts should be made to develop economic development and CO_(2)sequestration technologies for offshore CO_(2)-rich gas fields.
基金supported by CAMS Innovation Fund for Medical Sciences(2022-I2M-2-002 and 2022-I2M-1e014,China)the Non-Profit Central Research Institute Fund of Chinese Academy of Medical Sciences(2020-JKCS-019,China).
文摘Osteoarthritis(OA)is an aging-associated disease characterized by joint stiffness pain and destroyed articular cartilage.Traditional treatments for OA are limited to alleviating various OA symptoms.There is a lack of drugs available in clinical practice that can truly repair cartilage damage.Here,we developed the chondroitin sulfate analog CS-semi5,semi-synthesized from chondroitin sulfate A.In vivo,CS-semi5 alleviated inflammation,provided analgesic effects,and protected cartilage in the modified Hulth OA rat model and papain-induced OA rat model.A bioinformatics analysis was performed on samples from OA patients and an exosome analysis on papain-induced OA rats,revealing miR-122-5p as the key regulator associated with CS-semi5 in OA treatment.Binding prediction revealed that miR-122-5p acted on the 30-untranslated region of p38 mitogen-activated protein kinase,which was related to MMP13 regulation.Subsequent in vitro experiments revealed that CS-semi5 effectively reduced cartilage degeneration and maintained matrix homeostasis by inhibiting matrix breakdown through the miR-122-5p/p38/MMP13 axis,which was further validated in the articular cartilage of OA rats.This is the first study to investigate the semi-synthesized chondroitin sulfate CS-semi5,revealing its cartilageprotecting,anti-inflammatory,and analgesic properties that show promising therapeutic effects in OA via the miR-122-5p/p38/MMP13 pathway.
基金supported in part by a Grant in-Aid for Scientific Research B(22H03573)of the Japan Society for the Promotion of Science(JSPS)in part by the National Natural Science Foundation of China(92067109,61873119)+1 种基金in part by Shenzhen Science and Technology Program(ZDSYS20210623092007023,GJHZ20210705141808024)in part by Guangdong Key Program(2021QN02X794)。
文摘Recent achievements in deep learning(DL)have demonstrated its potential in predicting traffic flows.Such predictions are beneficial for understanding the situation and making traffic control decisions.However,most state-of-the-art DL models are consi-dered“black boxes”with little to no transparency of the underlying mechanisms for end users.Some previous studies attempted to“open the black box”and increase the interpretability of generated predictions.However,handling complex models on large-scale spatiotemporal data and discovering salient spatial and temporal patterns that significantly influence traffic flow remain challenging.To overcome these challenges,we present TrafPS,a visual analytics approach for interpreting traffic prediction outcomes to support decision-making in traffic management and urban planning.The measurements region SHAP and trajectory SHAP are proposed to quantify the impact of flow patterns on urban traffic at different levels.Based on the task requirements from domain experts,we employed an interactive visual interface for the multi-aspect exploration and analysis of significant flow patterns.Two real-world case studies demonstrate the effectiveness of TrafPS in identifying key routes and providing decision-making support for urban planning.
