OBJECTIVE:To find alternatives to natural musk,this study compared the pharmacological effects of cultivated musk,synthetic musk,and natural musk.The aim is to address the dual challenge of clinical demand for muskbas...OBJECTIVE:To find alternatives to natural musk,this study compared the pharmacological effects of cultivated musk,synthetic musk,and natural musk.The aim is to address the dual challenge of clinical demand for muskbased medicines and the endangered status of the musk deer population.METHODS:This study aimed to establish a rat model of acute cerebral ischemia/reperfusion injury(CI/RI)by creating a middle cerebral artery occlusion and reperfusion model.Methods including enzyme-linked immunosorbent assay kits,hematoxylin and eosin staining,Nissl staining,immunohistochemistry,and Western blot were employed to compare the extent of brain tissue damage,inflammatory factor levels,and platelet-related indicators in rats treated with musk from different sources(natural musk,cultivated musk,and synthetic musk),thereby evaluating their differences in neuroprotection.Analysis was performed using one-way analysis of variance.RESULTS:Results indicated that pretreatment with musk demonstrated a positive impact on neurological function by reducing cerebral infarction size,decreasing cerebral edema severity,increasing calcitonin gene related peptide levels,inhibiting 5-hydroxytryptamine release,and preserving the blood-brain barrier integrity.Notably,natural musk exhibited superior antithrombotic properties compared to cultivated and synthetic musk,primarily evidenced by its ability to inhibit platelet aggregation rate,improve cerebral blood perfusion,reduce platelet activating factor receptor protein expression,and lower thromboxane A2 levels.Cultivated musk was observed to elevate catalase and superoxide dismutase levels while concurrently dampening inducible nitric oxide synthase activity,thereby mitigating oxidative damage and also diminishing tumor necrosis factor-αand interleukin-1βcontents along with Glial fibrillary acidic protein expression,enhancing anti-inflammatory capacity.CONCLUSION:Musk sourced from diverse origins exhibits profound neuroprotective qualities against acute CI/RI in rats.Particularly,natural musk demonstrated a specific propensity towards reinforcing antithrombotic effects,whereas cultivated musk excelled in augmenting anti-inflammatory and antioxidative defenses,offering efficacious protection against acute CI/RI.The findings bolster the credibility of strategically employing diverse sources of musk as a preventive strategy against ischemic strokes.展开更多
Fabricating macroscale smart actuators that can convert light energy into other forms of energy,especially mechanical and electrical energy,is of great significance.Herein,a simple and efficient 4D printed method for ...Fabricating macroscale smart actuators that can convert light energy into other forms of energy,especially mechanical and electrical energy,is of great significance.Herein,a simple and efficient 4D printed method for fabricating photomechanical actuators based on micro/nano-scale crystals is developed.The high versatility and generality of this method are successfully demonstrated using nine different types of photoresponsive crystalline actuators,including acylhydrazone-,anthracene-,olefin-,and azobenzene-based molecular crystals and covalent organic frameworks(COFs).The low-cost neutral silicone sealant elastomer is first chosen as the photomechanical 4D printing matrix.Notably,these actuators can be used to perform bionic motions(the first windmills spin using crystalline material,dragonflies fly,and sunflowers bloom)under the stimulation of visible light and can realize energy conversion from mechanical energy into electricity when coupled with a piezoelectric membrane.This work provides new insights into the design and manufacturing of smart photomechanical actuators and electricity generators and expands the application scope of COFs.展开更多
This study aims to reveal the influence of Local Momentum Ratio(LMR)on the combustion efficiency of an LOX/GCH4 pintle injector from the perspective of spray characteristics.Hot fire tests were conducted to establish ...This study aims to reveal the influence of Local Momentum Ratio(LMR)on the combustion efficiency of an LOX/GCH4 pintle injector from the perspective of spray characteristics.Hot fire tests were conducted to establish the relationship between combustion efficiency and LMR.The spray characteristics for different LMRs were simulated by the validated volume of fluid-to-discrete phase model method,taking into account the combustion chamber wall confinement.Subsequently,the difference in combustion efficiency was analyzed by comparing the spray simulation results of backpressure conditions similar to hot fire tests.The results indicate that combustion efficiency increased initially(LMR=1.12-1.64)and then decreased(LMR>1.64).Quantitative analysis revealed a linear correlation(R^(2)=0.95)between LMR and combustion efficiency within 1.12<LMR<1.64.As the LMR increased,the improvement in combustion efficiency was attributed to a wider spray distribution range and smaller droplet sizes.The area of the mantle recirculation zone that is detrimental to combustion decreased by approximately 38%,and the droplet size reduced from 37 to 16μm.This effectively enhanced both the mixing of the propellant and the evaporation process.When the LMR exceeded the critical value(1.64 in this study),the impingement of liquid oxygen on the combustion chamber wall was confirmed via overheating discoloration marks on the inner surface of combustion chamber's cylindrical section.The impingement of liquid oxygen on the combustion chamber wall increased the transport of liquid oxygen to the wall,directly reducing the mixing quality and combustion efficiency.The outcomes of this study provide the practical guidance for design and improvement in combustion efficiency of the pintle injector thrust chamber.展开更多
基金Supported by Key Project of National Natural Science Foundation of Sichuan:Research on the Mechanism of Detoxification and Synergistic Effects of Sichuan-Produced Toxic Authentic Medicinal Herbs Croton Seed and Aconite Root(No.2024NSFSC0054)National Interdisciplinary Innovation Team of Traditional Chinese Medicine:Multidisciplinary Innovation Team for Multidimensional Evaluation of Southwest Chinese Characteristic Traditional Chinese Medicine Resources(No.ZYYCXTD-D-202209)Sichuan Chinese Medicine Science and Technology Industry Innovation Team:Innovative Team for Multidimensional Evaluation and Product Development of Characteristic Traditional Chinese Medicine Resources(No.2022C001)。
文摘OBJECTIVE:To find alternatives to natural musk,this study compared the pharmacological effects of cultivated musk,synthetic musk,and natural musk.The aim is to address the dual challenge of clinical demand for muskbased medicines and the endangered status of the musk deer population.METHODS:This study aimed to establish a rat model of acute cerebral ischemia/reperfusion injury(CI/RI)by creating a middle cerebral artery occlusion and reperfusion model.Methods including enzyme-linked immunosorbent assay kits,hematoxylin and eosin staining,Nissl staining,immunohistochemistry,and Western blot were employed to compare the extent of brain tissue damage,inflammatory factor levels,and platelet-related indicators in rats treated with musk from different sources(natural musk,cultivated musk,and synthetic musk),thereby evaluating their differences in neuroprotection.Analysis was performed using one-way analysis of variance.RESULTS:Results indicated that pretreatment with musk demonstrated a positive impact on neurological function by reducing cerebral infarction size,decreasing cerebral edema severity,increasing calcitonin gene related peptide levels,inhibiting 5-hydroxytryptamine release,and preserving the blood-brain barrier integrity.Notably,natural musk exhibited superior antithrombotic properties compared to cultivated and synthetic musk,primarily evidenced by its ability to inhibit platelet aggregation rate,improve cerebral blood perfusion,reduce platelet activating factor receptor protein expression,and lower thromboxane A2 levels.Cultivated musk was observed to elevate catalase and superoxide dismutase levels while concurrently dampening inducible nitric oxide synthase activity,thereby mitigating oxidative damage and also diminishing tumor necrosis factor-αand interleukin-1βcontents along with Glial fibrillary acidic protein expression,enhancing anti-inflammatory capacity.CONCLUSION:Musk sourced from diverse origins exhibits profound neuroprotective qualities against acute CI/RI in rats.Particularly,natural musk demonstrated a specific propensity towards reinforcing antithrombotic effects,whereas cultivated musk excelled in augmenting anti-inflammatory and antioxidative defenses,offering efficacious protection against acute CI/RI.The findings bolster the credibility of strategically employing diverse sources of musk as a preventive strategy against ischemic strokes.
基金the National Natural Science Foundation of China(22175099,22205116,22301147)National Key Research and Development Program of China(2021YFC2102100)+1 种基金Frontiers Science Center for New Organic Matter of Nankai University(63181206)111 Project(B12015).
文摘Fabricating macroscale smart actuators that can convert light energy into other forms of energy,especially mechanical and electrical energy,is of great significance.Herein,a simple and efficient 4D printed method for fabricating photomechanical actuators based on micro/nano-scale crystals is developed.The high versatility and generality of this method are successfully demonstrated using nine different types of photoresponsive crystalline actuators,including acylhydrazone-,anthracene-,olefin-,and azobenzene-based molecular crystals and covalent organic frameworks(COFs).The low-cost neutral silicone sealant elastomer is first chosen as the photomechanical 4D printing matrix.Notably,these actuators can be used to perform bionic motions(the first windmills spin using crystalline material,dragonflies fly,and sunflowers bloom)under the stimulation of visible light and can realize energy conversion from mechanical energy into electricity when coupled with a piezoelectric membrane.This work provides new insights into the design and manufacturing of smart photomechanical actuators and electricity generators and expands the application scope of COFs.
基金co-supported by the National Science Foundation Project,China(No.2019-JCJQ-ZQ-019)the National Natural Science Foundation of China(Nos.52476141 and T2221002)。
文摘This study aims to reveal the influence of Local Momentum Ratio(LMR)on the combustion efficiency of an LOX/GCH4 pintle injector from the perspective of spray characteristics.Hot fire tests were conducted to establish the relationship between combustion efficiency and LMR.The spray characteristics for different LMRs were simulated by the validated volume of fluid-to-discrete phase model method,taking into account the combustion chamber wall confinement.Subsequently,the difference in combustion efficiency was analyzed by comparing the spray simulation results of backpressure conditions similar to hot fire tests.The results indicate that combustion efficiency increased initially(LMR=1.12-1.64)and then decreased(LMR>1.64).Quantitative analysis revealed a linear correlation(R^(2)=0.95)between LMR and combustion efficiency within 1.12<LMR<1.64.As the LMR increased,the improvement in combustion efficiency was attributed to a wider spray distribution range and smaller droplet sizes.The area of the mantle recirculation zone that is detrimental to combustion decreased by approximately 38%,and the droplet size reduced from 37 to 16μm.This effectively enhanced both the mixing of the propellant and the evaporation process.When the LMR exceeded the critical value(1.64 in this study),the impingement of liquid oxygen on the combustion chamber wall was confirmed via overheating discoloration marks on the inner surface of combustion chamber's cylindrical section.The impingement of liquid oxygen on the combustion chamber wall increased the transport of liquid oxygen to the wall,directly reducing the mixing quality and combustion efficiency.The outcomes of this study provide the practical guidance for design and improvement in combustion efficiency of the pintle injector thrust chamber.
