Dibutyltin dilaurate functions as a stabilizer for polyvinyl chloride. In this study, experimental rats were intragastrically administered 5, 10, or 20 mg/kg dibutyltin dilaurate to model sub-chronic poisoning. After ...Dibutyltin dilaurate functions as a stabilizer for polyvinyl chloride. In this study, experimental rats were intragastrically administered 5, 10, or 20 mg/kg dibutyltin dilaurate to model sub-chronic poisoning. After exposure, our results showed the activities of superoxide dismutase and glutathione peroxidase decreased in rat brain tissue, while the malondialdehyde and nitric oxide content, as well as nitric oxide synthase activity in rat brain tissue increased. The cell cycle in the right parietal cortex was disordered and the rate of apoptosis increased. DNA damage was aggravated in the cerebral cortex, and the ultrastructure of the right parietal cortex tissues was altered. The above changes became more apparent with exposure to increasing doses of dibutyltin dilaurate. Our experimental findings confirmed the neurotoxicity of dibutyltin dilaurate in rat brain tissues, and demonstrated that the poisoning was dose-dependent.展开更多
According to the soft-switching pulsed SAW (Submerged arc weld) weld power supply based on the double closed-loop constant current control mode, a small signal mathematic model of main circuit of soft-switching SAW in...According to the soft-switching pulsed SAW (Submerged arc weld) weld power supply based on the double closed-loop constant current control mode, a small signal mathematic model of main circuit of soft-switching SAW inverter was established by applying the method of three-terminal switching device modeling method, and the math-ematic model of double closed-loop phase-shift control system circuit was established by applying the method of state-space averaging method. Dynamic performance of the inverter was analyzed on base of the established math-ematic model, and the tested wave of dynamic performance was shown by experimentation. Research and experimentation show that relation between structure of the power source circuit and dynamic performance of the controlling system can be announced by the established mathematic model, which provides development of power supply and optimized design of controlling parameter with theoretical guidance.展开更多
To explore how decomposed Microcystis-dominant cyanobacterial blooms affect submerged macrophytes,the submerged plant Myriophyllum spicatum was exposed to cell extracts from microcystin(MC)-and non-MC-producing Microc...To explore how decomposed Microcystis-dominant cyanobacterial blooms affect submerged macrophytes,the submerged plant Myriophyllum spicatum was exposed to cell extracts from microcystin(MC)-and non-MC-producing Microcystis strains in a laboratory experiment.Results showed that both Mcracystis cell extracts exerted obvious damages to plant biomass,photosynthesis,primary and secondary metabolism measures,and resistance of plant antioxidant systems,with MC-producing Microcystis having stronger effects due to the presence of MCs.Cyanotoxins other than MCs responsible for the negative effects from both strains needs further identification.The Shannon diversity and Chao1 indices of epiphytic and planktonic bacteria were decreased by the cell extracts from both Microcystis strains.However,epiphytic and planktonic bacterial communities responded differently to cell extracts at the genus level.The dominant genera of planktonic bacteria including Enterobacter,Pseudomonas,and Novosphingobium from phylum Proteobacteria,Chryseobacterium from phylum Bacteroidetes,and Microbacterium from Actinobacteriota in the treatments with cell extracts were previously reported to have strains with algicidal and MC-degrading capabilities.B acterial genes associated with energy production and conversion,amino acid transport and metabolism,and inorganic ion transport and metabolism,were more abundant in both treatments than the control for planktonic bacteria,but less abundant for epiphytic bacteria.We speculate that planktonic bacterial communities have the potential to use and degrade substances derived from Microcystis cell extracts,which may be beneficial for M.spicatum to alleviate damages from Microcystis.Further research is needed to verify the structure and function dynamics of epiphytic and planktonic bacteria in the interaction between cyanobacteria and submerged macrophytes.展开更多
BACKGROUND: To this date,specific molecular markers for early diagnosis and prognosis monitoring of craniocerebral injury in clinical medicine do not exist. Therefore,differential detection of specific proteins might ...BACKGROUND: To this date,specific molecular markers for early diagnosis and prognosis monitoring of craniocerebral injury in clinical medicine do not exist. Therefore,differential detection of specific proteins might play an important role in diagnosis and treatment of this type of brain injury. OBJECTIVE: To compare differential cerebral cortical protein expression of craniocerebral injury patients and normal subjects through the use of proteomics. DESIGN: Contrast observation. SETTING: Department of Neurosurgery,Xiangya Hospital of Central South University. PARTICIPANTS: Ten patients (6 males and 4 females,20-58 years old),with severe craniocerebral injury,were selected at the Department of Neurosurgery,Xiangya Hospital of Central South University,from June 2004 to December 2006. All patients were diagnosed with CT test and Glasgow test (scores < 8). Surgery was performed 4-12 hours after craniocerebral injury,and injured cortical tissues of the frontal and temporal lobes were resected for sampling. At the same time,control cortical tissues were collected from frontal and temporal lobes of 2 epileptic patients who underwent hippocampus-nucleus amygdala resection,and 2 lateral ventricular tumor patients who underwent tumor resection. The participants and their relatives provided con-firmed consent,and this study received confirmed consent from the local ethics committee. METHODS: Ten samples from injured patients and 4 normal samples were compared through the use of proteomics. Total protein was separated by using two-dimensional electrophoresis with immobilized pH gra-dients,and the differential protein expressions were compared using image analysis after blue-sliver staining. Differential protein spot expressions were analyzed with a matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI/TOF MS) and electrospray ionization-quadrupole time of flight mass spectrometry (ESI-Qq TOF MS). MAIN OUTCOME MEASURES: ① Two-dimensional electrophoresis of protein from cerebral cortex; ② differential protein expression. RESULTS: ① Two-dimensional electrophoresis of protein from cerebral cortex: two-dimensional gel elec-trophoretogram,which is considered to have high resolution and consistent duplication,was performed on injured cortical tissues and normal cortical tissues. The image analysis system detected 21 differential protein spots. ② Differential protein spot expressions: mass spectrometry resulted in 17 differential protein spots that related to metabolic response,oxidative stress response,and signal transduction. CONCLUSION: MALDI/TOF MS and ESI-Qq TOF MS are exceptional methods for evaluating differential protein expression. Results from this study indicated 17 different craniocerebral injury-associated proteins.展开更多
Pipe belt conveyor is a new type of environmentally friendly and efficient bulk conveying equipment.In the design of the roller,the belt and the driving motor of pipe belt conveyor,the sag resistance is a key paramete...Pipe belt conveyor is a new type of environmentally friendly and efficient bulk conveying equipment.In the design of the roller,the belt and the driving motor of pipe belt conveyor,the sag resistance is a key parameter.Meanwhile,the normal force between the conveyor belt and the roller group is the other important factor need be considered and has a great influence on the sag resistance.This paper analyzes a pipe belt conveyor with a diameter of 150 mm to study the calculation method of normal force.And the relationship between the normal force and the sag resistance is explored.Firstly,the normal force is decomposed into three components related to the forming force of belt,material gravity and belt gravity.So it can be expressed as a linear combination of these three quantities,and the coefficients of each component are obtained based on the dynamic analysis of belt-roller.The results show that the coefficient is mainly affected by the material filling rate,and is almost not affected by the distance between the rollers and the density of the material.The calculation method of the normal force is eventually obtained.Secondly,the normal force in the case of different material filling rates is tested by experiments,and the calculation method of the normal force is verified.Thirdly,the variation law of the sag resistance in the case of different roller group spacing and material filling rate is studied by the dynamic model.It is found that the roller group spacing and material filling rate affects the sag resistance by changing the normal force.There is a power function relationship between the sag resistance and the normal force.In the case of different roller group spacing and material filling rate,the relationship among the sag resistance and the normal force remains unchanged.This study results are of great significance to the design of pipe belt conveyor.展开更多
Background:Wheat flour maturation affects the aggregation and structural stability of proteins.The number of high-molecular-weight glutenin subunits(HMW-GSs)differs in various wheat varieties.The effects of Dx2 absenc...Background:Wheat flour maturation affects the aggregation and structural stability of proteins.The number of high-molecular-weight glutenin subunits(HMW-GSs)differs in various wheat varieties.The effects of Dx2 absence on the protein aggregation characteristics and thermal sta-bility of flour were investigated during 120 d of maturation using near-isogenic lines(NILs).Results:The absence of Dx2 delayed and decreased the protein aggregation of flours during maturation,i.e.the maturation-induced increases were later and smaller for glutenin,glutenin macropolymer(GMP),glutenin/gliadin ratio,β-sheets,andβ-sheet/a-helix ratio in HMW-D1a without Dx2 than in HMW-D1p with Dx2;these differences were ascribed to the weaker interactions between the sulfhydryl(-SH)groups,disulfide bonds(-S-S-),and hydrophobicity in the flours without Dx2.Flour maturation caused the dough microstructures to be more compact and denser,thereby increasing the flour thermal stability as observed by a higher denaturation peak temperature(Tp),enthalpy of thermal transition(△H),and degradation temperature(Td),These changes led to better dough properties such as dough development time,dough stability time,and protein weakening,but the optimal stage in HMW-D1a without Dx2was reached later.Conclusion:These findings deepen the understanding of how HMW-GS Dx2 modifies protein structures during flour maturation.展开更多
Dear Editor,Promyelocytic leukemia(PML)is the scaffold protein that organizes PML bod-ies,which are nuclear membraneless organelles involved in various biologi-cal processes,including tumor suppres-sion and antiviral ...Dear Editor,Promyelocytic leukemia(PML)is the scaffold protein that organizes PML bod-ies,which are nuclear membraneless organelles involved in various biologi-cal processes,including tumor suppres-sion and antiviral responses(Ugge et al.,2022).Early electron microscopic analy-ses revealed contacts between the sur-face of PML bodies and chromatin struc-ture(Corpet et al.,2020).In fact,sev-eral chromatin and cell cycle regulators,such as TIP60,P300,and heterochro-matin protein 1(HP1),are localized in PML bodies in interphase cells(Corpet et al.,2020).展开更多
Background and Aims:The safety and efficacy of mesenchymal stem cells(MSCs)in the treatment of acute-onchronic liver failure(ACLF)have been validated.However,the impact of the pathological ACLF microenvironment on MSC...Background and Aims:The safety and efficacy of mesenchymal stem cells(MSCs)in the treatment of acute-onchronic liver failure(ACLF)have been validated.However,the impact of the pathological ACLF microenvironment on MSCs is less well understood.This study was designed to explore the changes in the functional properties of MSCs exposed to ACLF serum.Methods:MSCs were cultured in the presence of 10%,30%and 50%serum concentrations from ACLF patients and healthy volunteers.Then,the cell morphology,phenotype,apoptosis and proliferation of MSCs were evaluated,including the immunosuppressive effects.Subsequently,mRNA sequencing analysis was used to identify the molecules and pathways involved in MSC functional changes in the context of ACLF.Results:In the presence of ACLF serum,MSC morphology significantly changed but phenotype did not.Besides,MSC proliferation activity was weakened,while the apoptosis rate was lightly increased.Most importantly,the immunosuppressive function of MSCs was enhanced in a lowconcentration serum environment but transformed into a proinflammatory response in a high-concentration serum environment.RNA sequencing indicated that 10%serum concentration from ACLF patients mediated the PI3K-Akt pathway to enhance the anti-inflammatory effect of MSCs,while the 50%serum concentration from ACLF patients promoted the conversion of MSCs into a proinflammatory function by affecting the cell cycle.Conclusions:The 50%ACLF serum concentration is more similar to the environment in the human body,which means that direct peripheral blood intravenous infusion of MSCs may reduce the effect of transplantation.Combining treatments of plasma exchange to reduce harmful substances in serum may promote MSCs to exert a stronger anti-inflammatory effect.展开更多
Emerging evidence showed that 2,3,7,8-Tetrachlorodibenzo-p-dioxin(TCDD) could induce expression of certain reactivation-associated genes in astrocytes, however, the consequent cellular effects and molecular mechanisms...Emerging evidence showed that 2,3,7,8-Tetrachlorodibenzo-p-dioxin(TCDD) could induce expression of certain reactivation-associated genes in astrocytes, however, the consequent cellular effects and molecular mechanisms are still unclear. During the process of astrocyte reactivation, migration is a critical cellular event. In the present study, we employed woundhealing assay and Transwell? motility assay to explore the effects of TCDD on cell migration in primary cultured rat cortical astrocytes. We found that upon TCDD treatments at relative low concentrations(10^(-10) and/or 10^(-9) mol/L), the ability of primary astrocytes to migrate horizontally and vertically was promoted. In line with this cellular effect, the mR NA expression of two promigratory genes, including cell division cycle 42(CDC42) and matrix metalloproteinase 2(MMP2)was induced by TCDD treatment. Dioxin exerts its toxic effects mainly through aryl hydrocarbon receptor(AhR) pathway. So the role of AhR pathway in the pro-migratory effects of TCDD was examined using an AhR antagonist, CH223191. We found that application of CH223191 significantly reversed the pro-migratory effects of TCDD. Interestingly, the basal ability of horizontal migration as well as basal levels of CDC42 and MMP2 expression were dramatically reduced suggesting a possible physiological role of AhR in maintaining the endogenous migration ability of the primary astrocytes. These findings support the notion that dioxin promotes astrocyte reactivation at molecular and cellular levels.展开更多
Background:Invasive sphenoid sinus aspergillosis is a rare but life-threatening condition usually found in immunocompromised patients.When involving cavernous sinus and surrounding structures,patients are frequently m...Background:Invasive sphenoid sinus aspergillosis is a rare but life-threatening condition usually found in immunocompromised patients.When involving cavernous sinus and surrounding structures,patients are frequently misdiagnosed with a neoplasm or sellar abscess.Timely diagnosis and intervention are crucial to patients’outcomes.The objective of this study is to review cases of invasive sphenoid sinus aspergillosis to describe disease manifestations,imaging features,treatment,and outcome.Case presentation:We describe four patients with invasive sphenoid sinus aspergillosis misdiagnosed as sellar tumors preoperatively.The mass was completely removed in three patients and partially removed in one patient microscopically.Pathological examinations confirmed Aspergillus in all cases.All four patients received anti-fungal agents postoperatively.There was no recurrence at the time of each patient’s follow-up date.One patient with complete resection was lost to follow-up while the other three patients’neurologic function improved.Additionally,we performed a systematic review regarding invasive sphenoid sinus aspergillosis of existing English literature.Conclusion:With regard to clinical symptoms,headache,vision impairment,and ophthalmoplegia were observed in over half of the patients in the literature.A sellar mass with bone destruction on CT and involvement of cavernous sinus is highly suggestive of invasive fungal sphenoid sinusitis.Immediate surgical removal of the lesion is recommended for invasive sphenoid sinus aspergillosis to preserve nerve function and increase the likelihood of survival.展开更多
The automatic feature extracting and matching for large amount of linear pushbroom imagery with higher and higher resolution is urgent and challenging in three dimensional reconstructions, remote sensing and mapping. ...The automatic feature extracting and matching for large amount of linear pushbroom imagery with higher and higher resolution is urgent and challenging in three dimensional reconstructions, remote sensing and mapping. Affine & scale-invariant heterogeneous pyramid feature is proposed in this paper, along with the new scale-invariant analysis method, the detecting of the key points, the affine & scale-invariant descriptor, the steering method of the matching, and the quasi-dense matching algorithm based on the extensive epipolar geometry. The automatic matching is devised for the linear pushbroom imagery. The whole process is executed on lunar images of the highest resolution of ~7 m/pixel(or ~1 m/pixel in the lower orbits) from the Chinese Chang’e 2 satellite, it runs robustly at present, and resulting in large amounts of well-distributed-correspondences with accuracy of 0.3 pixels and excellent reliability, which gives great support for the further exploration both on the Moon and the Earth.展开更多
Over the last 20 years,intensive research has been focused on the specific mechanisms mediating the pancreatic β-cell injury.Both the decreased viability and the dysfunction of β-cells have become the key factors in...Over the last 20 years,intensive research has been focused on the specific mechanisms mediating the pancreatic β-cell injury.Both the decreased viability and the dysfunction of β-cells have become the key factors in the development of dia betes mellitus.Thus,it is of utmost importance to elucidate the discrete pathological changes in pancreatic β-cells within the context of the various lipotoxicity models.The goal of these studies is to generate evidence to improve not only the clinical treatment for dia betics,but also modulate the diet and activities of groups at high risk for diabetes.In this regard,we review the role of lipotoxicity in pancreatic β-cell injury and identify potential therapeutic targets in this cell model.展开更多
Intracranial pressure(ICP)is one of the most important indexes in neurosurgery.It is essential for doctors to determine the numeric value and changes of ICP,whether before or after an operation.Although external ventr...Intracranial pressure(ICP)is one of the most important indexes in neurosurgery.It is essential for doctors to determine the numeric value and changes of ICP,whether before or after an operation.Although external ventricular drainage(EVD)is the gold standard for monitoring ICP,more and more novel monitoring methods are being applied clinically.Invasive wired ICP monitoring is still the most commonly used in practice.Meanwhile,with the rise and development of various novel technologies,non-invasive types and invasive wireless types are gradually being used clinically or in the testing phase,as a complimentary approach of ICP management.By choosing appropriate monitoring methods,clinical neurosurgeons are able to obtain ICP values safely and effectively under particular conditions.This article introduces diverse monitoring methods and compares the advantages and disadvantages of different monitoring methods.Moreover,this review may enable clinical neurosurgeons to have a broader view of ICP monitoring.展开更多
Nuclear power plays a key role as renewable energy in alleviating the worldwide energy shortage.The material degradation caused by high-temperature and high-flux neutron irradiation is the most concerning issue for nu...Nuclear power plays a key role as renewable energy in alleviating the worldwide energy shortage.The material degradation caused by high-temperature and high-flux neutron irradiation is the most concerning issue for nuclear reactor safety.A large number of He atoms produced through the(n,α)transmutation reaction diffuse and migrate in metals and accumulate to form He bubbles because of the extremely low solubility of He atoms in metal materials.The helium bubbles gather at the grain boundary or grain to cause swelling,hardening,embrittlement,and other damages to the in-core structural components.This paper mainly summarizes the research progress on He irradiation in steel and iron-based alloys,including the diffusion and accumulation of He atoms,the nucleation and growth of He bubbles,and the microstructure and macroscopic degradation of material performance caused by He irradiation.The mechanism of helium irradiation-induced corrosion in steel and iron-based alloys in recent years is reviewed as well.Moreover,the investigations on irradiation performance in additive manufactured stainless steels are summarized,and the mechanism of irradiation resistance is prospected.展开更多
文摘Dibutyltin dilaurate functions as a stabilizer for polyvinyl chloride. In this study, experimental rats were intragastrically administered 5, 10, or 20 mg/kg dibutyltin dilaurate to model sub-chronic poisoning. After exposure, our results showed the activities of superoxide dismutase and glutathione peroxidase decreased in rat brain tissue, while the malondialdehyde and nitric oxide content, as well as nitric oxide synthase activity in rat brain tissue increased. The cell cycle in the right parietal cortex was disordered and the rate of apoptosis increased. DNA damage was aggravated in the cerebral cortex, and the ultrastructure of the right parietal cortex tissues was altered. The above changes became more apparent with exposure to increasing doses of dibutyltin dilaurate. Our experimental findings confirmed the neurotoxicity of dibutyltin dilaurate in rat brain tissues, and demonstrated that the poisoning was dose-dependent.
文摘According to the soft-switching pulsed SAW (Submerged arc weld) weld power supply based on the double closed-loop constant current control mode, a small signal mathematic model of main circuit of soft-switching SAW inverter was established by applying the method of three-terminal switching device modeling method, and the math-ematic model of double closed-loop phase-shift control system circuit was established by applying the method of state-space averaging method. Dynamic performance of the inverter was analyzed on base of the established math-ematic model, and the tested wave of dynamic performance was shown by experimentation. Research and experimentation show that relation between structure of the power source circuit and dynamic performance of the controlling system can be announced by the established mathematic model, which provides development of power supply and optimized design of controlling parameter with theoretical guidance.
基金Supported by the National Program for the Introduction of High-end Foreign Experts(No.G2021026024L)the National Natural Science Foundation of China(Nos.31700405,U1904124)+1 种基金the Major Public Welfare Projects in Henan Province(No.201300311300)the Breeding Project of Henan Normal University(No.HNU2021PL05)。
文摘To explore how decomposed Microcystis-dominant cyanobacterial blooms affect submerged macrophytes,the submerged plant Myriophyllum spicatum was exposed to cell extracts from microcystin(MC)-and non-MC-producing Microcystis strains in a laboratory experiment.Results showed that both Mcracystis cell extracts exerted obvious damages to plant biomass,photosynthesis,primary and secondary metabolism measures,and resistance of plant antioxidant systems,with MC-producing Microcystis having stronger effects due to the presence of MCs.Cyanotoxins other than MCs responsible for the negative effects from both strains needs further identification.The Shannon diversity and Chao1 indices of epiphytic and planktonic bacteria were decreased by the cell extracts from both Microcystis strains.However,epiphytic and planktonic bacterial communities responded differently to cell extracts at the genus level.The dominant genera of planktonic bacteria including Enterobacter,Pseudomonas,and Novosphingobium from phylum Proteobacteria,Chryseobacterium from phylum Bacteroidetes,and Microbacterium from Actinobacteriota in the treatments with cell extracts were previously reported to have strains with algicidal and MC-degrading capabilities.B acterial genes associated with energy production and conversion,amino acid transport and metabolism,and inorganic ion transport and metabolism,were more abundant in both treatments than the control for planktonic bacteria,but less abundant for epiphytic bacteria.We speculate that planktonic bacterial communities have the potential to use and degrade substances derived from Microcystis cell extracts,which may be beneficial for M.spicatum to alleviate damages from Microcystis.Further research is needed to verify the structure and function dynamics of epiphytic and planktonic bacteria in the interaction between cyanobacteria and submerged macrophytes.
基金the National Natural Science Foundation of China, No. 30500558,30672149Program for New Century Excellent Talents in University,No.NCET2007-70
文摘BACKGROUND: To this date,specific molecular markers for early diagnosis and prognosis monitoring of craniocerebral injury in clinical medicine do not exist. Therefore,differential detection of specific proteins might play an important role in diagnosis and treatment of this type of brain injury. OBJECTIVE: To compare differential cerebral cortical protein expression of craniocerebral injury patients and normal subjects through the use of proteomics. DESIGN: Contrast observation. SETTING: Department of Neurosurgery,Xiangya Hospital of Central South University. PARTICIPANTS: Ten patients (6 males and 4 females,20-58 years old),with severe craniocerebral injury,were selected at the Department of Neurosurgery,Xiangya Hospital of Central South University,from June 2004 to December 2006. All patients were diagnosed with CT test and Glasgow test (scores < 8). Surgery was performed 4-12 hours after craniocerebral injury,and injured cortical tissues of the frontal and temporal lobes were resected for sampling. At the same time,control cortical tissues were collected from frontal and temporal lobes of 2 epileptic patients who underwent hippocampus-nucleus amygdala resection,and 2 lateral ventricular tumor patients who underwent tumor resection. The participants and their relatives provided con-firmed consent,and this study received confirmed consent from the local ethics committee. METHODS: Ten samples from injured patients and 4 normal samples were compared through the use of proteomics. Total protein was separated by using two-dimensional electrophoresis with immobilized pH gra-dients,and the differential protein expressions were compared using image analysis after blue-sliver staining. Differential protein spot expressions were analyzed with a matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI/TOF MS) and electrospray ionization-quadrupole time of flight mass spectrometry (ESI-Qq TOF MS). MAIN OUTCOME MEASURES: ① Two-dimensional electrophoresis of protein from cerebral cortex; ② differential protein expression. RESULTS: ① Two-dimensional electrophoresis of protein from cerebral cortex: two-dimensional gel elec-trophoretogram,which is considered to have high resolution and consistent duplication,was performed on injured cortical tissues and normal cortical tissues. The image analysis system detected 21 differential protein spots. ② Differential protein spot expressions: mass spectrometry resulted in 17 differential protein spots that related to metabolic response,oxidative stress response,and signal transduction. CONCLUSION: MALDI/TOF MS and ESI-Qq TOF MS are exceptional methods for evaluating differential protein expression. Results from this study indicated 17 different craniocerebral injury-associated proteins.
基金Supported by National Natural Science Foundation of China (Grant No. 51705144)Hunan Provincial Science and Technology Major Project of China (Grant No. 2015GK1003)Jiangsu Provincial Mine Electromechanical Equipment Key Laboratory Development Fund of China (Grant No. JSKL-MMEE-2018-2)
文摘Pipe belt conveyor is a new type of environmentally friendly and efficient bulk conveying equipment.In the design of the roller,the belt and the driving motor of pipe belt conveyor,the sag resistance is a key parameter.Meanwhile,the normal force between the conveyor belt and the roller group is the other important factor need be considered and has a great influence on the sag resistance.This paper analyzes a pipe belt conveyor with a diameter of 150 mm to study the calculation method of normal force.And the relationship between the normal force and the sag resistance is explored.Firstly,the normal force is decomposed into three components related to the forming force of belt,material gravity and belt gravity.So it can be expressed as a linear combination of these three quantities,and the coefficients of each component are obtained based on the dynamic analysis of belt-roller.The results show that the coefficient is mainly affected by the material filling rate,and is almost not affected by the distance between the rollers and the density of the material.The calculation method of the normal force is eventually obtained.Secondly,the normal force in the case of different material filling rates is tested by experiments,and the calculation method of the normal force is verified.Thirdly,the variation law of the sag resistance in the case of different roller group spacing and material filling rate is studied by the dynamic model.It is found that the roller group spacing and material filling rate affects the sag resistance by changing the normal force.There is a power function relationship between the sag resistance and the normal force.In the case of different roller group spacing and material filling rate,the relationship among the sag resistance and the normal force remains unchanged.This study results are of great significance to the design of pipe belt conveyor.
基金supported by the Key Science and Technology Project of Shaanxi Agricultural Collaborative Innovation and Extension Alliance(No.LMZD202104)the Introduction of Talents for Scientific Research of State Key Laboratory of North China Crop Improvement and Regulation(No.NCCIR2020RC-11).
文摘Background:Wheat flour maturation affects the aggregation and structural stability of proteins.The number of high-molecular-weight glutenin subunits(HMW-GSs)differs in various wheat varieties.The effects of Dx2 absence on the protein aggregation characteristics and thermal sta-bility of flour were investigated during 120 d of maturation using near-isogenic lines(NILs).Results:The absence of Dx2 delayed and decreased the protein aggregation of flours during maturation,i.e.the maturation-induced increases were later and smaller for glutenin,glutenin macropolymer(GMP),glutenin/gliadin ratio,β-sheets,andβ-sheet/a-helix ratio in HMW-D1a without Dx2 than in HMW-D1p with Dx2;these differences were ascribed to the weaker interactions between the sulfhydryl(-SH)groups,disulfide bonds(-S-S-),and hydrophobicity in the flours without Dx2.Flour maturation caused the dough microstructures to be more compact and denser,thereby increasing the flour thermal stability as observed by a higher denaturation peak temperature(Tp),enthalpy of thermal transition(△H),and degradation temperature(Td),These changes led to better dough properties such as dough development time,dough stability time,and protein weakening,but the optimal stage in HMW-D1a without Dx2was reached later.Conclusion:These findings deepen the understanding of how HMW-GS Dx2 modifies protein structures during flour maturation.
基金supported by grants from the Ministry of Science and Technology of the People’s Republic of China and the National Natural Science Foundation of China(2022YFA1303100,32090040,92254302,92153302,2022YFA0806800,2022YFA1302700,2017YFA0503600,31621002,91853115,21922706,22177106)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB19040000)+1 种基金the Ministry of Education(IRT_17R102 and 2011340213001)the Fundamental Research Funds for the Central Universities(WK2070000194).
文摘Dear Editor,Promyelocytic leukemia(PML)is the scaffold protein that organizes PML bod-ies,which are nuclear membraneless organelles involved in various biologi-cal processes,including tumor suppres-sion and antiviral responses(Ugge et al.,2022).Early electron microscopic analy-ses revealed contacts between the sur-face of PML bodies and chromatin struc-ture(Corpet et al.,2020).In fact,sev-eral chromatin and cell cycle regulators,such as TIP60,P300,and heterochro-matin protein 1(HP1),are localized in PML bodies in interphase cells(Corpet et al.,2020).
基金Acknowledgements The authors gratefully acknowledge the support of the National Key Research and Development Program of China （Grant No. 2016YFF0203400）, the National Natural Science Foundation of China （Grant Nos. 51575168 and 51375152）, the Project of National Science and Technology Supporting Plan （Grant No. 2015BAF32B03）, and the Science Research Key Program of Educational Department of Hunan Province of China （Grant No. 16A180）. The authors appreciate the support provided by the Collaborative Innovation Center of Intelligent New Energy Vehicle, the Hunan Collaborative Innovation Center for Green Car.
基金This study was supported by grants from the Natural Science Foundation of China(No.82070611 and 81873572)National Major Science and Technology Project for the Prevention and Treatment of AIDS and Viral Hepatitis(No.2018ZX10302204002 and 2018ZX10302205-002)+3 种基金Guangzhou Science and Technology Plan Projects(No.201904010442)Sun Yatsen University Clinical Research 5010 Program(No.2018009)Research Project on Degree and Postgraduate Education Reform in Guangdong Province(No.2018JGXM04)Young Teacher Training Program of Sun Yat-sen University(No.16ykpy40).
文摘Background and Aims:The safety and efficacy of mesenchymal stem cells(MSCs)in the treatment of acute-onchronic liver failure(ACLF)have been validated.However,the impact of the pathological ACLF microenvironment on MSCs is less well understood.This study was designed to explore the changes in the functional properties of MSCs exposed to ACLF serum.Methods:MSCs were cultured in the presence of 10%,30%and 50%serum concentrations from ACLF patients and healthy volunteers.Then,the cell morphology,phenotype,apoptosis and proliferation of MSCs were evaluated,including the immunosuppressive effects.Subsequently,mRNA sequencing analysis was used to identify the molecules and pathways involved in MSC functional changes in the context of ACLF.Results:In the presence of ACLF serum,MSC morphology significantly changed but phenotype did not.Besides,MSC proliferation activity was weakened,while the apoptosis rate was lightly increased.Most importantly,the immunosuppressive function of MSCs was enhanced in a lowconcentration serum environment but transformed into a proinflammatory response in a high-concentration serum environment.RNA sequencing indicated that 10%serum concentration from ACLF patients mediated the PI3K-Akt pathway to enhance the anti-inflammatory effect of MSCs,while the 50%serum concentration from ACLF patients promoted the conversion of MSCs into a proinflammatory function by affecting the cell cycle.Conclusions:The 50%ACLF serum concentration is more similar to the environment in the human body,which means that direct peripheral blood intravenous infusion of MSCs may reduce the effect of transplantation.Combining treatments of plasma exchange to reduce harmful substances in serum may promote MSCs to exert a stronger anti-inflammatory effect.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Nos.XDB14030401,XDB14030402)the Natural Science Foundation of China (Nos.21377160,21525730)Tianjin Municipal Science and Technology Commission (No.14JCQNJC11300)
文摘Emerging evidence showed that 2,3,7,8-Tetrachlorodibenzo-p-dioxin(TCDD) could induce expression of certain reactivation-associated genes in astrocytes, however, the consequent cellular effects and molecular mechanisms are still unclear. During the process of astrocyte reactivation, migration is a critical cellular event. In the present study, we employed woundhealing assay and Transwell? motility assay to explore the effects of TCDD on cell migration in primary cultured rat cortical astrocytes. We found that upon TCDD treatments at relative low concentrations(10^(-10) and/or 10^(-9) mol/L), the ability of primary astrocytes to migrate horizontally and vertically was promoted. In line with this cellular effect, the mR NA expression of two promigratory genes, including cell division cycle 42(CDC42) and matrix metalloproteinase 2(MMP2)was induced by TCDD treatment. Dioxin exerts its toxic effects mainly through aryl hydrocarbon receptor(AhR) pathway. So the role of AhR pathway in the pro-migratory effects of TCDD was examined using an AhR antagonist, CH223191. We found that application of CH223191 significantly reversed the pro-migratory effects of TCDD. Interestingly, the basal ability of horizontal migration as well as basal levels of CDC42 and MMP2 expression were dramatically reduced suggesting a possible physiological role of AhR in maintaining the endogenous migration ability of the primary astrocytes. These findings support the notion that dioxin promotes astrocyte reactivation at molecular and cellular levels.
文摘Background:Invasive sphenoid sinus aspergillosis is a rare but life-threatening condition usually found in immunocompromised patients.When involving cavernous sinus and surrounding structures,patients are frequently misdiagnosed with a neoplasm or sellar abscess.Timely diagnosis and intervention are crucial to patients’outcomes.The objective of this study is to review cases of invasive sphenoid sinus aspergillosis to describe disease manifestations,imaging features,treatment,and outcome.Case presentation:We describe four patients with invasive sphenoid sinus aspergillosis misdiagnosed as sellar tumors preoperatively.The mass was completely removed in three patients and partially removed in one patient microscopically.Pathological examinations confirmed Aspergillus in all cases.All four patients received anti-fungal agents postoperatively.There was no recurrence at the time of each patient’s follow-up date.One patient with complete resection was lost to follow-up while the other three patients’neurologic function improved.Additionally,we performed a systematic review regarding invasive sphenoid sinus aspergillosis of existing English literature.Conclusion:With regard to clinical symptoms,headache,vision impairment,and ophthalmoplegia were observed in over half of the patients in the literature.A sellar mass with bone destruction on CT and involvement of cavernous sinus is highly suggestive of invasive fungal sphenoid sinusitis.Immediate surgical removal of the lesion is recommended for invasive sphenoid sinus aspergillosis to preserve nerve function and increase the likelihood of survival.
基金supported by the National Defense Science and Technology Product of China (No. 20060826)
文摘The automatic feature extracting and matching for large amount of linear pushbroom imagery with higher and higher resolution is urgent and challenging in three dimensional reconstructions, remote sensing and mapping. Affine & scale-invariant heterogeneous pyramid feature is proposed in this paper, along with the new scale-invariant analysis method, the detecting of the key points, the affine & scale-invariant descriptor, the steering method of the matching, and the quasi-dense matching algorithm based on the extensive epipolar geometry. The automatic matching is devised for the linear pushbroom imagery. The whole process is executed on lunar images of the highest resolution of ~7 m/pixel(or ~1 m/pixel in the lower orbits) from the Chinese Chang’e 2 satellite, it runs robustly at present, and resulting in large amounts of well-distributed-correspondences with accuracy of 0.3 pixels and excellent reliability, which gives great support for the further exploration both on the Moon and the Earth.
基金This work was supported by the National Natural Science Foundation of China(Nos.91129727,81020108031,and 30973558)the Major Specialized Research Fund from the Ministry of Science and Technology in China(No.2009ZX09103-144).
文摘Over the last 20 years,intensive research has been focused on the specific mechanisms mediating the pancreatic β-cell injury.Both the decreased viability and the dysfunction of β-cells have become the key factors in the development of dia betes mellitus.Thus,it is of utmost importance to elucidate the discrete pathological changes in pancreatic β-cells within the context of the various lipotoxicity models.The goal of these studies is to generate evidence to improve not only the clinical treatment for dia betics,but also modulate the diet and activities of groups at high risk for diabetes.In this regard,we review the role of lipotoxicity in pancreatic β-cell injury and identify potential therapeutic targets in this cell model.
文摘Intracranial pressure(ICP)is one of the most important indexes in neurosurgery.It is essential for doctors to determine the numeric value and changes of ICP,whether before or after an operation.Although external ventricular drainage(EVD)is the gold standard for monitoring ICP,more and more novel monitoring methods are being applied clinically.Invasive wired ICP monitoring is still the most commonly used in practice.Meanwhile,with the rise and development of various novel technologies,non-invasive types and invasive wireless types are gradually being used clinically or in the testing phase,as a complimentary approach of ICP management.By choosing appropriate monitoring methods,clinical neurosurgeons are able to obtain ICP values safely and effectively under particular conditions.This article introduces diverse monitoring methods and compares the advantages and disadvantages of different monitoring methods.Moreover,this review may enable clinical neurosurgeons to have a broader view of ICP monitoring.
基金sponsored by the National Natural Science Foundation of China(Grant No.52073176)the Shenzhen International Cooperation Research Science and Technology Program(No.GJHZ20200731095203011).
文摘Nuclear power plays a key role as renewable energy in alleviating the worldwide energy shortage.The material degradation caused by high-temperature and high-flux neutron irradiation is the most concerning issue for nuclear reactor safety.A large number of He atoms produced through the(n,α)transmutation reaction diffuse and migrate in metals and accumulate to form He bubbles because of the extremely low solubility of He atoms in metal materials.The helium bubbles gather at the grain boundary or grain to cause swelling,hardening,embrittlement,and other damages to the in-core structural components.This paper mainly summarizes the research progress on He irradiation in steel and iron-based alloys,including the diffusion and accumulation of He atoms,the nucleation and growth of He bubbles,and the microstructure and macroscopic degradation of material performance caused by He irradiation.The mechanism of helium irradiation-induced corrosion in steel and iron-based alloys in recent years is reviewed as well.Moreover,the investigations on irradiation performance in additive manufactured stainless steels are summarized,and the mechanism of irradiation resistance is prospected.
