Aiming at the global design issue of transpiration cooling thermal protection system,a self-driven circulation loop is proposed as the internal coolant flow passage for the transpiration cooling structure to achieve a...Aiming at the global design issue of transpiration cooling thermal protection system,a self-driven circulation loop is proposed as the internal coolant flow passage for the transpiration cooling structure to achieve adaptive cooling.To enhance the universality of this internal cooling pipe design and facilitate its application,numerical studies are conducted on this systemwith four commonly used cooling mediums as coolant.Firstly,the accuracy of the numerical method is verified through an established experimental platform.Then,transient numerical simulations are performed on the flow states of different cooling mediums in the new self-circulation system.Based on the numerical result,the flow,phase change,and heat transfer characteristics of different cooling mediums are analyzed.Differences in fluid velocity and latent heat of phase change result in significant variation in heat exchange capacity among different coolingmediums,with the maximumdifference reaching up to 3 times.Besides,faster circulation speed leads to greater heat transfer capacity,with a maximum of 7600 W/m^(2).Consequently,the operating mechanism and cooling laws of the natural circulation system is further investigated,providing a reference for the practical application of this system.展开更多
This study investigates the performance of a natural draft dry cooling tower group in crosswind conditions through numerical analysis.A comprehensive three-dimensional model is developed to analyze the steady-state an...This study investigates the performance of a natural draft dry cooling tower group in crosswind conditions through numerical analysis.A comprehensive three-dimensional model is developed to analyze the steady-state and dynamic behavior of the towers.The impact of wind speed and direction on heat rejection capacity and flow patterns is examined.Results indicate that crosswinds negatively affect the overall heat transfer capacity,with higher crosswind speeds leading to decreased heat transfer.Notably,wind direction plays a significant role,particularly at 0°.Moreover,tower response time increases with higher crosswind speeds due to increased turbulence and the formation of vortices.The response times are generally similar for wind directions of 45°and 90°,but differ when facing 0,where the leeward tower exhibits a shorter response time compared to the windward tower.These findings provide valuable insights into the performance of natural draft dry cooling tower groups under crosswind conditions,which can inform the design and operation of similar systems in practical applications.展开更多
BACKGROUND Esophageal stricture ranks among the most significant complications following endoscopic submucosal dissection(ESD).Excessive fibrotic repair is a typical pathological feature leading to stenosis after ESD....BACKGROUND Esophageal stricture ranks among the most significant complications following endoscopic submucosal dissection(ESD).Excessive fibrotic repair is a typical pathological feature leading to stenosis after ESD.AIM To examine the effectiveness and underlying mechanism of Kangfuxin solution(KFX)in mitigating excessive fibrotic repair of the esophagus post-ESD.METHODS Pigs received KFX at 0.74 mL/kg/d for 21 days after esophageal full circumferential ESD.Endoscopic examinations occurred on days 7 and 21 post-ESD.In vitro,recombinant transforming growth factor(TGF)-β1(5 ng/mL)induced a fibrotic microenvironment in primary esophageal fibroblasts(pEsF).After 24 hours of KFX treatment(at 1.5%,1%,and 0.5%),expression ofα-smooth muscle actin-2(ACTA2),fibronectin(FN),and type collagen I was assessed.Profibrotic signaling was analyzed,including TGF-β1,Smad2/3,and phosphor-smad2/3(p-Smad2/3).RESULTS Compared to the Control group,the groups treated with KFX and prednisolone exhibited reduced esophageal stenosis,lower weight loss rates,and improved food tolerance 21 d after ESD.After treatment,Masson staining revealed thinner and less dense collagen fibers in the submucosal layer.Additionally,the expression of fibrotic effector molecules was notably inhibited.Mechanistically,KFX downregulated the transduction levels of fibrotic functional molecules such as TGF-β1,Smad2/3,and p-Smad2/3.In vitro,pEsF exposed to TGF-β1-induced fibrotic microenvironment displayed increased fibrotic activity,which was reversed by KFX treatment,leading to reduced activation of ACTA2,FN,and collagen I.The 1.5%KFX treatment group showed decreased expression of p-Smad 2/3 in TGF-β1-activated pEsF.CONCLUSION KFX showed promise as a therapeutic option for post-full circumferential esophageal ESD strictures,potentially by suppressing fibroblast fibrotic activity through modulation of the TGF-β1/Smads signaling pathway.展开更多
Natural products,with their remarkable structural and biological diversity,have historically served as a vital bridge between chemistry,the life sciences,and medicine.They not only provide essential scaffolds for drug...Natural products,with their remarkable structural and biological diversity,have historically served as a vital bridge between chemistry,the life sciences,and medicine.They not only provide essential scaffolds for drug discovery but also inspire innovative strategies in drug development.The biomimetic synthesis of natural products employs principles from biomimicry,applying inspiration from biogenetic processes to design synthetic strategies that mimic biosynthetic processes.Biomimetic synthesis is a highly efficient approach in synthetic chemistry,as it addresses critical challenges in the synthesis of structurally complex natural products with significant biological and medicinal importance.It has gained widespread attention from researchers in chemistry,biology,pharmacy,and related fields,underscoring its interdisciplinary impact.In this perspective,we present recent advances and challenges in the biomimetic synthesis of natural products,along with the significance and prospects of this field,highlighting the transformative potential of biomimetic synthesis strategies for both chemical and biosynthetic approaches to natural product synthesis in the pursuit of novel therapeutic agents.展开更多
Stroke is the second leading cause of disability and mortality worldwide,imposing a substantial socioeconomic burden on individuals and healthcare systems.Annually,approximately 14 million people experience stroke,wit...Stroke is the second leading cause of disability and mortality worldwide,imposing a substantial socioeconomic burden on individuals and healthcare systems.Annually,approximately 14 million people experience stroke,with ischemic stroke comprising nearly 85%of cases,of which 10%to 20%involve large vessel occlusions.Currently,recombinant tissue plasminogen activator(tPA)remains the only approved pharmacological intervention.However,its utility is limited due to a narrow therapeutic window and low recanalization rates,making it applicable to only a minority of patients.Therefore,there is an urgent need for novel therapeutic strategies,including pharmacological advancements and combinatory treatments.Small-molecule natural medicines,particularly those derived from traditional Chinese herbs,have demonstrated significant therapeutic potential in ischemic stroke management.These compounds exert multiple neuroprotective effects,such as antioxidation,anti-inflammatory action,and inhibition of apoptosis,all of which are critical in mitigating stroke-induced cerebral damage.This review comprehensively examines the pathophysiology of acute ischemic stroke(AIS)and highlights the recent progress in the development of small-molecule natural medicines as promising therapeutic agents for cerebral ischemic stroke.展开更多
Natural products(NPs)have historically been a fundamental source for drug discovery.Yet the complex nature of NPs presents substantial challenges in pinpointing bioactive constituents,and corresponding targets.In the ...Natural products(NPs)have historically been a fundamental source for drug discovery.Yet the complex nature of NPs presents substantial challenges in pinpointing bioactive constituents,and corresponding targets.In the present study,an innovative natural product virtual screening-interaction-phenotype(NP-VIP)strategy that integrates virtual screening,chemical proteomics,and metabolomics to identify and validate the bioactive targets of NPs.This approach reduces false positive results and enhances the efficiency of target identification.Salvia miltiorrhiza(SM),a herb with recognized therapeutic potential against ischemic stroke(IS),was used to illustrate the workflow.Utilizing virtual screening,chemical proteomics,and metabolomics,potential therapeutic targets for SM in the IS treatment were identified,totaling 29,100,and 78,respectively.Further analysis via the NP-VIP strategy highlighted five high-confidence targets,including poly[ADP-ribose]polymerase 1(PARP1),signal transducer and activator of transcription 3(STAT3),amyloid precursor protein(APP),glutamate-ammonia ligase(GLUL),and glutamate decarboxylase 67(GAD67).These targets were subsequently validated and found to play critical roles in the neuroprotective effects of SM.The study not only underscores the importance of SM in treating IS but also sets a precedent for NP research,proposing a comprehensive approach that could be adapted for broader pharmacological explorations.展开更多
This paper presents a high-fidelity lumpedparameter(LP)thermal model(HF-LPTM)for permanent magnet synchronous machines(PMSMs)in electric vehicle(EV)applications,where various cooling techniques are considered,includin...This paper presents a high-fidelity lumpedparameter(LP)thermal model(HF-LPTM)for permanent magnet synchronous machines(PMSMs)in electric vehicle(EV)applications,where various cooling techniques are considered,including frame forced air/liquid cooling,oil jet cooling for endwinding,and rotor shaft cooling.To address the temperature misestimation in the LP thermal modelling due to assumptions of concentrated loss input and uniform heat flows,the developed HF-LPTM introduces two compensation thermal resistances for the winding and PM components,which are analytically derived from the multi-dimensional heat transfer equations and are robust against different load/thermal conditions.As validated by the finite element analysis method and experiments,the conventional LPTMs exhibit significant winding temperature deviations,while the proposed HF-LPTM can accurately predict both the midpoint and average temperatures.The developed HFLPTM is further used to assess the effectiveness of various cooling techniques under different scenarios,i.e.,steady-state thermal states under the rated load condition,and transient temperature profiles under city,freeway,and hybrid(city+freeway)driving cycles.Results indicate that no single cooling technique can maintain both winding and PM temperatures within safety limits.The combination of frame liquid cooling and oil jet cooling for end winding can sufficiently mitigate PMSM thermal stress in EV applications.展开更多
Agricultural intensification has led to an increase in monoculture and the use of chemical pesticides,resulting in a decline in biodiversity and a reduction in ecosystem services,particularly biological pest managemen...Agricultural intensification has led to an increase in monoculture and the use of chemical pesticides,resulting in a decline in biodiversity and a reduction in ecosystem services,particularly biological pest management.However,studies have shown that agroforestry can not only improve land productivity and biodiversity but also regulate some ecosystem services.This study reviews the impacts of physical and biological factors on herbivorous pests,parasites,and predatory natural enemies in fruit-crop agroforestry systems.Fruit-crop agroforestry systems provide high spatial heterogeneity by altering crop layouts,regulating the microclimate and soil quality,and offering food resources and shelter for natural enemies,thus promoting biological pest control.This enhances biological control and makes the agrocomplex system an effective tool for sustainable agriculture.Our research shows that volatile plant substances attract or repel pests and natural enemies based on the characteristics of the insects themselves.When scientifically designed,fruit-crop agroforestry systems provide high spatial heterogeneity and favorable microclimatic conditions,which enhance biological pest control and make the agroforestry system an effective tool for sustainable agriculture.Our research shows that fruit-crop agroforestry systems can provide richer food resources and habitat,enhancing biological pest control and improving pest management.展开更多
Natural antimicrobial peptides(AMPs)are promising candidates for the development of a new generation of antimicrobials to combat antibiotic-resistant pathogens.They have found extensive applications in the fields of m...Natural antimicrobial peptides(AMPs)are promising candidates for the development of a new generation of antimicrobials to combat antibiotic-resistant pathogens.They have found extensive applications in the fields of medicine,food,and agriculture.However,efficiently screening AMPs from natural sources poses several challenges,including low efficiency and high antibiotic resistance.This review focuses on the action mechanisms of AMPs,both through membrane and non-membrane routes.We thoroughly examine various highly efficient AMP screening methods,including whole-bacterial adsorption binding,cell membrane chromatography(CMC),phospholipid membrane chromatography binding,membranemediated capillary electrophoresis(CE),colorimetric assays,thin layer chromatography(TLC),fluorescence-based screening,genetic sequencing-based analysis,computational mining of AMP databases,and virtual screening methods.Additionally,we discuss potential developmental applications for enhancing the efficiency of AMP discovery.This review provides a comprehensive framework for identifying AMPs within complex natural product systems.展开更多
Gastric carcinoma(GC)is a malignancy with multifactorial involvement,multicellular regulation,and multistage evolution.The classic Correa's cascade of intestinal GC specifies a trilogy of malignant transformation ...Gastric carcinoma(GC)is a malignancy with multifactorial involvement,multicellular regulation,and multistage evolution.The classic Correa's cascade of intestinal GC specifies a trilogy of malignant transformation of the gastric mucosa,in which normal gastric mucosa gradually progresses from inactive or chronic active gastritis(Phase I)to gastric precancerous lesions(Phase II)and finally to GC(Phase III).Correa's cascade highlights the evolutionary pattern of GC and the importance of early intervention to prevent malignant transformation of the gastric mucosa.Intervening in early gastric mucosal lesions,i.e.,Phases I and II,will be the key strategy to prevent and treat GC.Natural products(NPs)have been an important source for drug development due to abundant sources,tremendous safety,and multiple pharmacodynamic mechanisms.This review is the first to investigate and summarize the multi-step effects and regulatory mechanisms of NPs on the Correa's cascade in gastric carcinogenesis.In Phase I,NPs modulate Helicobacter pylori urease activity,motility,adhesion,virulence factors,and drug resistance,thereby inhibiting H.pylori-induced gastric mucosal inflammation and oxidative stress,and facilitating ulcer healing.In Phase II,NPs modulate multiple pathways and mediators regulating gastric mucosal cell cycle,apoptosis,autophagy,and angiogenesis to reverse gastric precancerous lesions.In Phase III,NPs suppress cell proliferation,migration,invasion,angiogenesis,and cancer stem cells,induce apoptosis and autophagy,and enhance chemotherapeutic drug sensitivity for the treatment of GC.In contrast to existing work,we hope to uncover NPs with sequential therapeutic effects on multiple phases of GC development,providing new ideas for gastric cancer prevention,treatment,and drug development.展开更多
Background Cotton crop is infested by numerous arthropod pests from sowing to harvesting,causing substantial direct and indirect yield losses.Knowledge of seasonal population trends and the relative occurrence of pest...Background Cotton crop is infested by numerous arthropod pests from sowing to harvesting,causing substantial direct and indirect yield losses.Knowledge of seasonal population trends and the relative occurrence of pests and their natural enemies is required to minimize the pest population and yield losses.In the current study,analysis of the seasonal population trend of pests and natural enemies and their relative occurrence on cultivars of three cotton species in Central India has been carried out.Results A higher number and diversity of sucking pests were observed during the vegetative cotton growth stage(60 days after sowing),declining as the crop matured.With the exception of cotton jassid(Amrasca biguttula biguttula Ishida),which caused significant crop damage mainly from August to September;populations of other sucking insects seldom reached economic threshold levels(ETL)throughout the studied period.The bollworm complex populations were minimal,except for the pink bollworm(Pectinophora gossypiella Saunders),which re-emerged as a menace to cotton crops during the cotton cropping season 2017–2018 due to resistance development against Bt-cotton.A reasonably good number of predatory arthropods,including coccinellids,lacewings,and spiders,were found actively preying on the arthropod pest complex of the cotton crop during the early vegetative growth stage.Linear regression indicates a significant relationship between green boll infestations and pink bollworm moths in pheromone traps.Multiple linear regression analyse showed mean weekly weather at one-or two-week lag periods had a significant impact on sucking pest population(cotton aphid,cotton jassid,cotton whitefly,and onion thrips)fluctuation.Gossypium hirsutum cultivars RCH 2 and DCH 32,and G.barbadense cultivar Suvin were found susceptible to cotton jassid and onion thrips.Phule Dhanvantary,an G.arboreum cotton cultivar,demonstrated the highest tolerance among all evaluated cultivars against all sucking pests.Conclusion These findings have important implications for pest management in cotton crops.Susceptible cultivars warrant more attention for plant protection measures,making them more input-intensive.The choice of appropriate cultivars can help minimize input costs,thereby increasing net returns for cotton farmers.展开更多
Friction rolling additive manufacturing(FRAM)is a solid-state additive manufacturing technology that plasticizes the feed and deposits a material using frictional heat generated by the tool head.The thermal efficiency...Friction rolling additive manufacturing(FRAM)is a solid-state additive manufacturing technology that plasticizes the feed and deposits a material using frictional heat generated by the tool head.The thermal efficiency of FRAM,which depends only on friction to generate heat,is low,and the thermal-accumulation effect of the deposition process must be addressed.An FRAM heat-balance-control method that combines plasma-arc preheating and instant water cooling(PC-FRAM)is devised in this study,and a temperature field featuring rapidly increasing and decreasing temperature is constructed around the tool head.Additionally,2195-T87 Al-Li alloy is used as the feed material,and the effects of heating and cooling rates on the microstructure and mechanical properties are investigated.The results show that water cooling significantly improves heat accumulation during the deposition process.The cooling rate increases by 11.7 times,and the high-temperature residence time decreases by more than 50%.The grain size of the PC-FRAM sample is the smallest,i.e.,3.77±1.03μm,its dislocation density is the highest,and the number density of precipitates is the highest,the size of precipitates is the smallest,which shows the best precipitation-strengthening effect.The hardness test results are consistent with the precipitation distribution.The ultimate tensile strength,yield strength and elongation of the PC-FRAM samples are the highest(351±15.6 MPa,251.3±15.8 MPa and 16.25%±1.25%,respectively)among the samples investigated.The preheating and water-cooling-assisted deposition simultaneously increases the tensile strength and elongation of the deposited samples.The combination of preheating and instant cooling improves the deposition efficiency of FRAM and weakens the thermal-softening effect.展开更多
Recently,diffusion models have emerged as a promising paradigm for molecular design and optimization.However,most diffusion-based molecular generative models focus on modeling 2D graphs or 3D geom-etries,with limited ...Recently,diffusion models have emerged as a promising paradigm for molecular design and optimization.However,most diffusion-based molecular generative models focus on modeling 2D graphs or 3D geom-etries,with limited research on molecular sequence diffusion models.The International Union of Pure and Applied Chemistry(IUPAC)names are more akin to chemical natural language than the simplified molecular input line entry system(SMILES)for organic compounds.In this work,we apply an IUPAC-guided conditional diffusion model to facilitate molecular editing from chemical natural language to chemical language(SMILES)and explore whether the pre-trained generative performance of diffusion models can be transferred to chemical natural language.We propose DiffIUPAC,a controllable molecular editing diffusion model that converts IUPAC names to SMILES strings.Evaluation results demonstrate that our model out-performs existing methods and successfully captures the semantic rules of both chemical languages.Chemical space and scaffold analysis show that the model can generate similar compounds with diverse scaffolds within the specified constraints.Additionally,to illustrate the model’s applicability in drug design,we conducted case studies in functional group editing,analogue design and linker design.展开更多
In the contemporary medical landscape,the burgeoning interest in natural therapies,particularly for managing gastrointestinal disorders,has brought traditional Chinese medicine(TCM)to the forefront.This article explai...In the contemporary medical landscape,the burgeoning interest in natural therapies,particularly for managing gastrointestinal disorders,has brought traditional Chinese medicine(TCM)to the forefront.This article explains the core principles and clinical applications of TCM in treating these conditions,furthering the discourse through an examination of integrated TCM strategies,as demonstrated in the study by Zhou et al.While TCM has shown promising clinical outcomes,it encounters significant hurdles in standardization,mechanistic research,and clinical validation.Future investigations should aim to solidify the scientific underpinnings of TCM and expand its use in gastrointestinal disease management,striving for a seamless fusion of traditional and contemporary medical practices.展开更多
This study focuses on the thermal management of 4680-type cylindrical lithium-ion battery packs utilizing NCM811 chemistry.It establishes coupled multi-physics models for both immersion and serpentine cold plate cooli...This study focuses on the thermal management of 4680-type cylindrical lithium-ion battery packs utilizing NCM811 chemistry.It establishes coupled multi-physics models for both immersion and serpentine cold plate cooling systems.Through a combination of numerical simulation and experimental validation,the technical advantages and mechanisms of immersion cooling are systematically explored.Simulation results indicate that under a 3C fast-charging condition(inlet temperature 20℃,flow rate 36 L/min),the immersion cooling structure 3demonstrates a triple enhancement in thermal performance compared to the cold plate structure 1:a 13.06%reduction in peak temperature,a 31.67%decrease in overall maximum temperature difference,and a 47.62%decrease in single-cell temperature deviation,while also reducing flow resistance by 33.61%.Furthermore,based on the immersion cooling model,a small battery module comprising seven cylindrical cells was designed for thermal runaway testing via nail penetration.The results show that the peak temperature of the triggered cell was limited to 437.6℃,with a controllable temperature rise gradient of only 3.35℃/s and a rapid cooling rate of 0.6℃/s.The maximum temperature rise of adjacent cells was just 64.8℃,effectively inhibiting thermal propagation.Post-test disassembly revealed that the non-triggered cells retained>99.2%of their original voltage and>99%structural integrity,confirming the module’s ability to achieve“localized failure with global stability.”展开更多
Due to the complex high-temperature characteristics of hydrocarbon fuel,the research on the long-term working process of parallel channel structure under variable working conditions,especially under high heat-mass rat...Due to the complex high-temperature characteristics of hydrocarbon fuel,the research on the long-term working process of parallel channel structure under variable working conditions,especially under high heat-mass ratio,has not been systematically carried out.In this paper,the heat transfer and flow characteristics of related high temperature fuels are studied by using typical engine parallel channel structure.Through numeri⁃cal simulation and systematic experimental verification,the flow and heat transfer characteristics of parallel chan⁃nels under typical working conditions are obtained,and the effectiveness of high-precision calculation method is preliminarily established.It is known that the stable time required for hot start of regenerative cooling engine is about 50 s,and the flow resistance of parallel channel structure first increases and then decreases with the in⁃crease of equivalence ratio(The following equivalence ratio is expressed byΦ),and there is a flow resistance peak in the range ofΦ=0.5~0.8.This is mainly caused by the coupling effect of high temperature physical proper⁃ties,flow rate and pressure of fuel in parallel channels.At the same time,the cooling and heat transfer character⁃istics of parallel channels under some conditions of high heat-mass ratio are obtained,and the main factors affect⁃ing the heat transfer of parallel channels such as improving surface roughness and strengthening heat transfer are mastered.In the experiment,whenΦis less than 0.9,the phenomenon of local heat transfer enhancement and deterioration can be obviously observed,and the temperature rise of local structures exceeds 200℃,which is the risk of structural damage.Therefore,the reliability of long-term parallel channel structure under the condition of high heat-mass ratio should be fully considered in structural design.展开更多
The work takes a new liquid-cooling plate in a power battery with pin fins inside the channel as the object.A mathematical model is established via the central composite design of the response surface to study the rel...The work takes a new liquid-cooling plate in a power battery with pin fins inside the channel as the object.A mathematical model is established via the central composite design of the response surface to study the relationships among the length,width,height,and spacing of pin fins;the maximum temperature and temperature difference of the battery module;and the pressure drop of the liquid-cooling plate.Model accuracy is verified via variance analysis.The new liquid-cooling plate enables the power battery to work within an optimal temperature range.Appropriately increasing the length,width,and height and reducing the spacing of pin fins could reduce the temperature of the power battery module and improve the temperature uniformity.However,the pressure drop of the liquid-cooling plate increases.The structural parameters of the pin fins are optimized to minimize the maximum temperature and the temperature difference of the battery module as well as the pressure drop of the liquid-cooling plate.The errors between the values predicted and actual by the simulation test are 0.58%,4%,and 0.48%,respectively,which further verifies the model accuracy.The results reveal the influence of the structural parameters of the pin fins inside the liquid-cooling plate on its heat dissipation performance and pressure drop characteristics.A theoretical basis is provided for the design of liquid-cooling plates in power batteries and the optimization of structural parameters.展开更多
Spores and pollen,as ubiquitous organisms found in nature,possess a remarkable core-shell structure and intricate surface morphology.These tiny particles are notable for their dimensional uniformity,sustainable utiliz...Spores and pollen,as ubiquitous organisms found in nature,possess a remarkable core-shell structure and intricate surface morphology.These tiny particles are notable for their dimensional uniformity,sustainable utilization,environmental friendliness,porosity,amphiphilicity,and strong adhesive properties.In addition,they display excellent biocompatibility and biodegradability,which significantly enhances the stability and targeting of drugs within the body.Spores and pollen can be extracted using methods such as acidic solutions,alkaline solutions,or enzyme treatments to obtain sporopollenin,which is an extremely resilient and chemically inert complex biopolymer.The sporopollenin extracted through this process removes the original bioactive substances,such as cell nuclei,enzymes,and DNA,providing greater drug loading capacity and containing no potential allergens or immunogens,thus further enhancing its drug loading capacity and improving safety in therapeutic applications.Due to these beneficial attributes,spores,pollen and sporopollenin have gained widespread use in a variety of drug delivery systems,such as targeted delivery,sustained drug delivery,toxicity mitigation,flavor masking,vaccine delivery,delivery of labile substances,and other applications.This review introduces the types of natural spores and pollen commonly used in drug delivery systems,including their main components,common effects,and uses in drug delivery systems,and so on.It subsequently summarizes novel optimization methods in their processing,such as physical treatment,surface modification,and chemical modification,which enable higher drug loading efficiency,stability,and targeting,among other benefits.Additionally,this paper reviews the research progress and applications of natural spores,pollen,and sporopollenin in drug delivery systems,while also touching on some innovative research content,such as novel nanomotor microcarriers developed based on pollen.Based on these research findings,we further elaborate on the advantages of spores,pollen,and sporopollenin in drug delivery systems.For example,they have high stability and drug loading capacity,good adhesion,excellent targeting,and are easy to modify functionally.Currently,they show promising prospects in the fields of targeted drug delivery,sustained-release drug delivery,as well as the delivery of drugs that are effective but slightly toxic,and are often used in research on the treatment of diseases such as cancer and inflammation.We have also highlighted the challenges they face in various applications and identified some issues that need to be addressed,including difficulties in largescale production,the need to improve extraction and purification processes,and the existence of a low but still noteworthy risk of allergies,in order to fully leverage their potential in drug delivery applications.According to current research,although spores,pollen,and sporopollenin face some unresolved issues in clinical drug delivery,they still have great potential overall and are expected to become a new generation of green drug delivery platforms.In the future,further research into their unique physical and chemical properties and structural characteristics will help develop more efficient and stable drug delivery systems to meet diverse treatment needs.We believe that continued exploration of natural spores,pollen,and sporopollenin will drive this emerging field to achieve continuous breakthroughs and progress,ultimately making an important contribution to the cause of human health.展开更多
Hygroscopic hydrogel is a promising evaporativecooling material for high-power passive daytime cooling with water self-regeneration.However,undesired solar and environmental heating makes it a challenge to maintain su...Hygroscopic hydrogel is a promising evaporativecooling material for high-power passive daytime cooling with water self-regeneration.However,undesired solar and environmental heating makes it a challenge to maintain sub-ambient daytime cooling.While different strategies have been developed to mitigate heat gains,they inevitably sacrifice the evaporation and water regeneration due to highly coupled thermal and vapor transport.Here,an anisotropic synergistically performed insulation-radiation-evaporation(ASPIRE)cooler is developed by leveraging a dual-alignment structure both internal and external to the hydrogel for coordinated thermal and water transport.The ASPIRE cooler achieves an impressive average sub-ambient cooling temperature of~8.2℃ and a remarkable peak cooling power of 311 W m^(-2)under direct sunlight.Further examining the cooling mechanism reveals that the ASPIRE cooler reduces the solar and environmental heat gains without comprising the evaporation.Moreover,self-sustained multi-day cooling is possible with water self-regeneration at night under both clear and cloudy days.The synergistic design provides new insights toward high-power,sustainable,and all-weather passive cooling applications.展开更多
Radiative cooling is an environmentally friendly,passive cooling technology that operates without energy consumption.Current research primarily focuses on optimizing the optical properties of radiative cooling films t...Radiative cooling is an environmentally friendly,passive cooling technology that operates without energy consumption.Current research primarily focuses on optimizing the optical properties of radiative cooling films to enhance their cooling performance.In practical applications,thermal contact between the radiative cooling film and the object significantly influences the ultimate cooling performance.However,achieving optimal thermal contact has received limited attention.In this study,we propose and experimentally demonstrate a high-power,flexible,and magnetically attachable and detachable radiative cooling film.This film consists of polymer metasurface structures on a flexible magnetic layer.The monolithic design allows for convenient attachment to and detachment from steel or iron surfaces,ensuring optimal thermal contact with minimal thermal resistance and uniform temperature distribution.Our magnetic radiative cooling film exhibits superior cooling performance compared to non-magnetic alternatives.It can reduce the temperature of stainless-steel plates under sunlight by 15.2℃,which is 3.6℃ more than that achieved by non-magnetic radiative cooling films.The radiative cooling power can reach 259W·m^(-2) at a working temperature of 70℃.Unlike other commonly used attachment methods,such as thermal grease or one-off tape,our approach allows for detachment and reusability of the cooling film according to practical needs.This method offers great simplicity,flexibility,and cost-effectiveness,making it promising for broad applications,particularly on non-horizontal irregular surfaces previously considered challenging.展开更多
基金funded by Fei He,National Natural Science Foundation of China(contract no.52376154)Anhui Provincial Natural Science Foundation(contract no.2308085J21).
文摘Aiming at the global design issue of transpiration cooling thermal protection system,a self-driven circulation loop is proposed as the internal coolant flow passage for the transpiration cooling structure to achieve adaptive cooling.To enhance the universality of this internal cooling pipe design and facilitate its application,numerical studies are conducted on this systemwith four commonly used cooling mediums as coolant.Firstly,the accuracy of the numerical method is verified through an established experimental platform.Then,transient numerical simulations are performed on the flow states of different cooling mediums in the new self-circulation system.Based on the numerical result,the flow,phase change,and heat transfer characteristics of different cooling mediums are analyzed.Differences in fluid velocity and latent heat of phase change result in significant variation in heat exchange capacity among different coolingmediums,with the maximumdifference reaching up to 3 times.Besides,faster circulation speed leads to greater heat transfer capacity,with a maximum of 7600 W/m^(2).Consequently,the operating mechanism and cooling laws of the natural circulation system is further investigated,providing a reference for the practical application of this system.
基金Key Laboratory of Low-Grade Energy Utilization Technologies and Systems(LLEUTS-2023001)the Natural Science Foundation of Chongqing(CSTB2022NSCQ-MSX1470).
文摘This study investigates the performance of a natural draft dry cooling tower group in crosswind conditions through numerical analysis.A comprehensive three-dimensional model is developed to analyze the steady-state and dynamic behavior of the towers.The impact of wind speed and direction on heat rejection capacity and flow patterns is examined.Results indicate that crosswinds negatively affect the overall heat transfer capacity,with higher crosswind speeds leading to decreased heat transfer.Notably,wind direction plays a significant role,particularly at 0°.Moreover,tower response time increases with higher crosswind speeds due to increased turbulence and the formation of vortices.The response times are generally similar for wind directions of 45°and 90°,but differ when facing 0,where the leeward tower exhibits a shorter response time compared to the windward tower.These findings provide valuable insights into the performance of natural draft dry cooling tower groups under crosswind conditions,which can inform the design and operation of similar systems in practical applications.
基金Supported by Science and Technology Department of Sichuan Province,No.2020YFS0376National Natural Science Foundation of China,No.81900599Science and Technology Program of Hospital of TCM,Southwest Medical University,No.2022-CXTD-01.
文摘BACKGROUND Esophageal stricture ranks among the most significant complications following endoscopic submucosal dissection(ESD).Excessive fibrotic repair is a typical pathological feature leading to stenosis after ESD.AIM To examine the effectiveness and underlying mechanism of Kangfuxin solution(KFX)in mitigating excessive fibrotic repair of the esophagus post-ESD.METHODS Pigs received KFX at 0.74 mL/kg/d for 21 days after esophageal full circumferential ESD.Endoscopic examinations occurred on days 7 and 21 post-ESD.In vitro,recombinant transforming growth factor(TGF)-β1(5 ng/mL)induced a fibrotic microenvironment in primary esophageal fibroblasts(pEsF).After 24 hours of KFX treatment(at 1.5%,1%,and 0.5%),expression ofα-smooth muscle actin-2(ACTA2),fibronectin(FN),and type collagen I was assessed.Profibrotic signaling was analyzed,including TGF-β1,Smad2/3,and phosphor-smad2/3(p-Smad2/3).RESULTS Compared to the Control group,the groups treated with KFX and prednisolone exhibited reduced esophageal stenosis,lower weight loss rates,and improved food tolerance 21 d after ESD.After treatment,Masson staining revealed thinner and less dense collagen fibers in the submucosal layer.Additionally,the expression of fibrotic effector molecules was notably inhibited.Mechanistically,KFX downregulated the transduction levels of fibrotic functional molecules such as TGF-β1,Smad2/3,and p-Smad2/3.In vitro,pEsF exposed to TGF-β1-induced fibrotic microenvironment displayed increased fibrotic activity,which was reversed by KFX treatment,leading to reduced activation of ACTA2,FN,and collagen I.The 1.5%KFX treatment group showed decreased expression of p-Smad 2/3 in TGF-β1-activated pEsF.CONCLUSION KFX showed promise as a therapeutic option for post-full circumferential esophageal ESD strictures,potentially by suppressing fibroblast fibrotic activity through modulation of the TGF-β1/Smads signaling pathway.
基金financially supported by the National Key Research and Development Program of China(2023YFC3503902)the National Natural Science Foundation of China(82430108,82293681(82293680),and 82321004)+2 种基金the Guangdong Basic and Applied Basic Research Foundation(2022B1515120015 and 2024A1515030103)the Guangdong Major Project of Basic and Applied Basic Research(2023B0303000026)the Science and Technology Projects in Guangzhou(202102070001)。
文摘Natural products,with their remarkable structural and biological diversity,have historically served as a vital bridge between chemistry,the life sciences,and medicine.They not only provide essential scaffolds for drug discovery but also inspire innovative strategies in drug development.The biomimetic synthesis of natural products employs principles from biomimicry,applying inspiration from biogenetic processes to design synthetic strategies that mimic biosynthetic processes.Biomimetic synthesis is a highly efficient approach in synthetic chemistry,as it addresses critical challenges in the synthesis of structurally complex natural products with significant biological and medicinal importance.It has gained widespread attention from researchers in chemistry,biology,pharmacy,and related fields,underscoring its interdisciplinary impact.In this perspective,we present recent advances and challenges in the biomimetic synthesis of natural products,along with the significance and prospects of this field,highlighting the transformative potential of biomimetic synthesis strategies for both chemical and biosynthetic approaches to natural product synthesis in the pursuit of novel therapeutic agents.
基金supported by the National Natural Science Foundation of China(Nos.82174010 and 81973512)。
文摘Stroke is the second leading cause of disability and mortality worldwide,imposing a substantial socioeconomic burden on individuals and healthcare systems.Annually,approximately 14 million people experience stroke,with ischemic stroke comprising nearly 85%of cases,of which 10%to 20%involve large vessel occlusions.Currently,recombinant tissue plasminogen activator(tPA)remains the only approved pharmacological intervention.However,its utility is limited due to a narrow therapeutic window and low recanalization rates,making it applicable to only a minority of patients.Therefore,there is an urgent need for novel therapeutic strategies,including pharmacological advancements and combinatory treatments.Small-molecule natural medicines,particularly those derived from traditional Chinese herbs,have demonstrated significant therapeutic potential in ischemic stroke management.These compounds exert multiple neuroprotective effects,such as antioxidation,anti-inflammatory action,and inhibition of apoptosis,all of which are critical in mitigating stroke-induced cerebral damage.This review comprehensively examines the pathophysiology of acute ischemic stroke(AIS)and highlights the recent progress in the development of small-molecule natural medicines as promising therapeutic agents for cerebral ischemic stroke.
基金supported by the National Natural Science Foundations of China(Grant No.:82204584)Liaoning Provincial Science and Technology Projects,China(Project No.:2021JH1/10400055).
文摘Natural products(NPs)have historically been a fundamental source for drug discovery.Yet the complex nature of NPs presents substantial challenges in pinpointing bioactive constituents,and corresponding targets.In the present study,an innovative natural product virtual screening-interaction-phenotype(NP-VIP)strategy that integrates virtual screening,chemical proteomics,and metabolomics to identify and validate the bioactive targets of NPs.This approach reduces false positive results and enhances the efficiency of target identification.Salvia miltiorrhiza(SM),a herb with recognized therapeutic potential against ischemic stroke(IS),was used to illustrate the workflow.Utilizing virtual screening,chemical proteomics,and metabolomics,potential therapeutic targets for SM in the IS treatment were identified,totaling 29,100,and 78,respectively.Further analysis via the NP-VIP strategy highlighted five high-confidence targets,including poly[ADP-ribose]polymerase 1(PARP1),signal transducer and activator of transcription 3(STAT3),amyloid precursor protein(APP),glutamate-ammonia ligase(GLUL),and glutamate decarboxylase 67(GAD67).These targets were subsequently validated and found to play critical roles in the neuroprotective effects of SM.The study not only underscores the importance of SM in treating IS but also sets a precedent for NP research,proposing a comprehensive approach that could be adapted for broader pharmacological explorations.
文摘This paper presents a high-fidelity lumpedparameter(LP)thermal model(HF-LPTM)for permanent magnet synchronous machines(PMSMs)in electric vehicle(EV)applications,where various cooling techniques are considered,including frame forced air/liquid cooling,oil jet cooling for endwinding,and rotor shaft cooling.To address the temperature misestimation in the LP thermal modelling due to assumptions of concentrated loss input and uniform heat flows,the developed HF-LPTM introduces two compensation thermal resistances for the winding and PM components,which are analytically derived from the multi-dimensional heat transfer equations and are robust against different load/thermal conditions.As validated by the finite element analysis method and experiments,the conventional LPTMs exhibit significant winding temperature deviations,while the proposed HF-LPTM can accurately predict both the midpoint and average temperatures.The developed HFLPTM is further used to assess the effectiveness of various cooling techniques under different scenarios,i.e.,steady-state thermal states under the rated load condition,and transient temperature profiles under city,freeway,and hybrid(city+freeway)driving cycles.Results indicate that no single cooling technique can maintain both winding and PM temperatures within safety limits.The combination of frame liquid cooling and oil jet cooling for end winding can sufficiently mitigate PMSM thermal stress in EV applications.
文摘Agricultural intensification has led to an increase in monoculture and the use of chemical pesticides,resulting in a decline in biodiversity and a reduction in ecosystem services,particularly biological pest management.However,studies have shown that agroforestry can not only improve land productivity and biodiversity but also regulate some ecosystem services.This study reviews the impacts of physical and biological factors on herbivorous pests,parasites,and predatory natural enemies in fruit-crop agroforestry systems.Fruit-crop agroforestry systems provide high spatial heterogeneity by altering crop layouts,regulating the microclimate and soil quality,and offering food resources and shelter for natural enemies,thus promoting biological pest control.This enhances biological control and makes the agrocomplex system an effective tool for sustainable agriculture.Our research shows that volatile plant substances attract or repel pests and natural enemies based on the characteristics of the insects themselves.When scientifically designed,fruit-crop agroforestry systems provide high spatial heterogeneity and favorable microclimatic conditions,which enhance biological pest control and make the agroforestry system an effective tool for sustainable agriculture.Our research shows that fruit-crop agroforestry systems can provide richer food resources and habitat,enhancing biological pest control and improving pest management.
基金supported by the National Natural Science Foundation of China(Grant Nos.:82373835,82304437,and 82173781)Regional Joint Fund Project of Guangdong Basic and Applied Basic Research Fund,China(Grant Nos.:2023A1515110417 and 2023A1515140131)+2 种基金Regional Joint Fund-Key Project of Guangdong Basic and Applied Basic Research Fund,China(Grant No.:2020B1515120033)the Key Field Projects of General Universities in Guangdong Province,China(Grant Nos.:2020ZDZX2057 and 2022ZDZX2056)Medical Scientific Research Foundation of Guangdong Province of China(Grant No.:A2022061).
文摘Natural antimicrobial peptides(AMPs)are promising candidates for the development of a new generation of antimicrobials to combat antibiotic-resistant pathogens.They have found extensive applications in the fields of medicine,food,and agriculture.However,efficiently screening AMPs from natural sources poses several challenges,including low efficiency and high antibiotic resistance.This review focuses on the action mechanisms of AMPs,both through membrane and non-membrane routes.We thoroughly examine various highly efficient AMP screening methods,including whole-bacterial adsorption binding,cell membrane chromatography(CMC),phospholipid membrane chromatography binding,membranemediated capillary electrophoresis(CE),colorimetric assays,thin layer chromatography(TLC),fluorescence-based screening,genetic sequencing-based analysis,computational mining of AMP databases,and virtual screening methods.Additionally,we discuss potential developmental applications for enhancing the efficiency of AMP discovery.This review provides a comprehensive framework for identifying AMPs within complex natural product systems.
基金supported by the Chengdu University of Traditional Chinese Medicine"Xinglin Scholars"Program,China(Grant No.:MPRC2023014).
文摘Gastric carcinoma(GC)is a malignancy with multifactorial involvement,multicellular regulation,and multistage evolution.The classic Correa's cascade of intestinal GC specifies a trilogy of malignant transformation of the gastric mucosa,in which normal gastric mucosa gradually progresses from inactive or chronic active gastritis(Phase I)to gastric precancerous lesions(Phase II)and finally to GC(Phase III).Correa's cascade highlights the evolutionary pattern of GC and the importance of early intervention to prevent malignant transformation of the gastric mucosa.Intervening in early gastric mucosal lesions,i.e.,Phases I and II,will be the key strategy to prevent and treat GC.Natural products(NPs)have been an important source for drug development due to abundant sources,tremendous safety,and multiple pharmacodynamic mechanisms.This review is the first to investigate and summarize the multi-step effects and regulatory mechanisms of NPs on the Correa's cascade in gastric carcinogenesis.In Phase I,NPs modulate Helicobacter pylori urease activity,motility,adhesion,virulence factors,and drug resistance,thereby inhibiting H.pylori-induced gastric mucosal inflammation and oxidative stress,and facilitating ulcer healing.In Phase II,NPs modulate multiple pathways and mediators regulating gastric mucosal cell cycle,apoptosis,autophagy,and angiogenesis to reverse gastric precancerous lesions.In Phase III,NPs suppress cell proliferation,migration,invasion,angiogenesis,and cancer stem cells,induce apoptosis and autophagy,and enhance chemotherapeutic drug sensitivity for the treatment of GC.In contrast to existing work,we hope to uncover NPs with sequential therapeutic effects on multiple phases of GC development,providing new ideas for gastric cancer prevention,treatment,and drug development.
基金Funding support for the Crop Pest Surveillance and Advisory Project(CROPSAP)。
文摘Background Cotton crop is infested by numerous arthropod pests from sowing to harvesting,causing substantial direct and indirect yield losses.Knowledge of seasonal population trends and the relative occurrence of pests and their natural enemies is required to minimize the pest population and yield losses.In the current study,analysis of the seasonal population trend of pests and natural enemies and their relative occurrence on cultivars of three cotton species in Central India has been carried out.Results A higher number and diversity of sucking pests were observed during the vegetative cotton growth stage(60 days after sowing),declining as the crop matured.With the exception of cotton jassid(Amrasca biguttula biguttula Ishida),which caused significant crop damage mainly from August to September;populations of other sucking insects seldom reached economic threshold levels(ETL)throughout the studied period.The bollworm complex populations were minimal,except for the pink bollworm(Pectinophora gossypiella Saunders),which re-emerged as a menace to cotton crops during the cotton cropping season 2017–2018 due to resistance development against Bt-cotton.A reasonably good number of predatory arthropods,including coccinellids,lacewings,and spiders,were found actively preying on the arthropod pest complex of the cotton crop during the early vegetative growth stage.Linear regression indicates a significant relationship between green boll infestations and pink bollworm moths in pheromone traps.Multiple linear regression analyse showed mean weekly weather at one-or two-week lag periods had a significant impact on sucking pest population(cotton aphid,cotton jassid,cotton whitefly,and onion thrips)fluctuation.Gossypium hirsutum cultivars RCH 2 and DCH 32,and G.barbadense cultivar Suvin were found susceptible to cotton jassid and onion thrips.Phule Dhanvantary,an G.arboreum cotton cultivar,demonstrated the highest tolerance among all evaluated cultivars against all sucking pests.Conclusion These findings have important implications for pest management in cotton crops.Susceptible cultivars warrant more attention for plant protection measures,making them more input-intensive.The choice of appropriate cultivars can help minimize input costs,thereby increasing net returns for cotton farmers.
基金supported by the National Natural Science Foundation of China(Nos.52275299,52105313)R&D Program of Beijing Municipal Education Commission(No.KM202210005036)+1 种基金Natural Science Foundation of Chongqing,China(No.CSTB2023NSCQ-MSX0701)National Defense Basic Research Projects of China(No.JCKY2022405C002).
文摘Friction rolling additive manufacturing(FRAM)is a solid-state additive manufacturing technology that plasticizes the feed and deposits a material using frictional heat generated by the tool head.The thermal efficiency of FRAM,which depends only on friction to generate heat,is low,and the thermal-accumulation effect of the deposition process must be addressed.An FRAM heat-balance-control method that combines plasma-arc preheating and instant water cooling(PC-FRAM)is devised in this study,and a temperature field featuring rapidly increasing and decreasing temperature is constructed around the tool head.Additionally,2195-T87 Al-Li alloy is used as the feed material,and the effects of heating and cooling rates on the microstructure and mechanical properties are investigated.The results show that water cooling significantly improves heat accumulation during the deposition process.The cooling rate increases by 11.7 times,and the high-temperature residence time decreases by more than 50%.The grain size of the PC-FRAM sample is the smallest,i.e.,3.77±1.03μm,its dislocation density is the highest,and the number density of precipitates is the highest,the size of precipitates is the smallest,which shows the best precipitation-strengthening effect.The hardness test results are consistent with the precipitation distribution.The ultimate tensile strength,yield strength and elongation of the PC-FRAM samples are the highest(351±15.6 MPa,251.3±15.8 MPa and 16.25%±1.25%,respectively)among the samples investigated.The preheating and water-cooling-assisted deposition simultaneously increases the tensile strength and elongation of the deposited samples.The combination of preheating and instant cooling improves the deposition efficiency of FRAM and weakens the thermal-softening effect.
基金supported by the Yonsei University graduate school Department of Integrative Biotechnology.
文摘Recently,diffusion models have emerged as a promising paradigm for molecular design and optimization.However,most diffusion-based molecular generative models focus on modeling 2D graphs or 3D geom-etries,with limited research on molecular sequence diffusion models.The International Union of Pure and Applied Chemistry(IUPAC)names are more akin to chemical natural language than the simplified molecular input line entry system(SMILES)for organic compounds.In this work,we apply an IUPAC-guided conditional diffusion model to facilitate molecular editing from chemical natural language to chemical language(SMILES)and explore whether the pre-trained generative performance of diffusion models can be transferred to chemical natural language.We propose DiffIUPAC,a controllable molecular editing diffusion model that converts IUPAC names to SMILES strings.Evaluation results demonstrate that our model out-performs existing methods and successfully captures the semantic rules of both chemical languages.Chemical space and scaffold analysis show that the model can generate similar compounds with diverse scaffolds within the specified constraints.Additionally,to illustrate the model’s applicability in drug design,we conducted case studies in functional group editing,analogue design and linker design.
基金Supported by the 2023 Government Funded Project of the Outstanding Talents Training Program in Clinical Medicine,No.ZF2023165Key Research and Development Projects of Hebei Province,No.18277731DNatural Science Foundation of Hebei Province,No.H202423105.
文摘In the contemporary medical landscape,the burgeoning interest in natural therapies,particularly for managing gastrointestinal disorders,has brought traditional Chinese medicine(TCM)to the forefront.This article explains the core principles and clinical applications of TCM in treating these conditions,furthering the discourse through an examination of integrated TCM strategies,as demonstrated in the study by Zhou et al.While TCM has shown promising clinical outcomes,it encounters significant hurdles in standardization,mechanistic research,and clinical validation.Future investigations should aim to solidify the scientific underpinnings of TCM and expand its use in gastrointestinal disease management,striving for a seamless fusion of traditional and contemporary medical practices.
文摘This study focuses on the thermal management of 4680-type cylindrical lithium-ion battery packs utilizing NCM811 chemistry.It establishes coupled multi-physics models for both immersion and serpentine cold plate cooling systems.Through a combination of numerical simulation and experimental validation,the technical advantages and mechanisms of immersion cooling are systematically explored.Simulation results indicate that under a 3C fast-charging condition(inlet temperature 20℃,flow rate 36 L/min),the immersion cooling structure 3demonstrates a triple enhancement in thermal performance compared to the cold plate structure 1:a 13.06%reduction in peak temperature,a 31.67%decrease in overall maximum temperature difference,and a 47.62%decrease in single-cell temperature deviation,while also reducing flow resistance by 33.61%.Furthermore,based on the immersion cooling model,a small battery module comprising seven cylindrical cells was designed for thermal runaway testing via nail penetration.The results show that the peak temperature of the triggered cell was limited to 437.6℃,with a controllable temperature rise gradient of only 3.35℃/s and a rapid cooling rate of 0.6℃/s.The maximum temperature rise of adjacent cells was just 64.8℃,effectively inhibiting thermal propagation.Post-test disassembly revealed that the non-triggered cells retained>99.2%of their original voltage and>99%structural integrity,confirming the module’s ability to achieve“localized failure with global stability.”
文摘Due to the complex high-temperature characteristics of hydrocarbon fuel,the research on the long-term working process of parallel channel structure under variable working conditions,especially under high heat-mass ratio,has not been systematically carried out.In this paper,the heat transfer and flow characteristics of related high temperature fuels are studied by using typical engine parallel channel structure.Through numeri⁃cal simulation and systematic experimental verification,the flow and heat transfer characteristics of parallel chan⁃nels under typical working conditions are obtained,and the effectiveness of high-precision calculation method is preliminarily established.It is known that the stable time required for hot start of regenerative cooling engine is about 50 s,and the flow resistance of parallel channel structure first increases and then decreases with the in⁃crease of equivalence ratio(The following equivalence ratio is expressed byΦ),and there is a flow resistance peak in the range ofΦ=0.5~0.8.This is mainly caused by the coupling effect of high temperature physical proper⁃ties,flow rate and pressure of fuel in parallel channels.At the same time,the cooling and heat transfer character⁃istics of parallel channels under some conditions of high heat-mass ratio are obtained,and the main factors affect⁃ing the heat transfer of parallel channels such as improving surface roughness and strengthening heat transfer are mastered.In the experiment,whenΦis less than 0.9,the phenomenon of local heat transfer enhancement and deterioration can be obviously observed,and the temperature rise of local structures exceeds 200℃,which is the risk of structural damage.Therefore,the reliability of long-term parallel channel structure under the condition of high heat-mass ratio should be fully considered in structural design.
基金supported by the Education and Teaching Research Project of Universities in Fujian Province(FBJY20230167).
文摘The work takes a new liquid-cooling plate in a power battery with pin fins inside the channel as the object.A mathematical model is established via the central composite design of the response surface to study the relationships among the length,width,height,and spacing of pin fins;the maximum temperature and temperature difference of the battery module;and the pressure drop of the liquid-cooling plate.Model accuracy is verified via variance analysis.The new liquid-cooling plate enables the power battery to work within an optimal temperature range.Appropriately increasing the length,width,and height and reducing the spacing of pin fins could reduce the temperature of the power battery module and improve the temperature uniformity.However,the pressure drop of the liquid-cooling plate increases.The structural parameters of the pin fins are optimized to minimize the maximum temperature and the temperature difference of the battery module as well as the pressure drop of the liquid-cooling plate.The errors between the values predicted and actual by the simulation test are 0.58%,4%,and 0.48%,respectively,which further verifies the model accuracy.The results reveal the influence of the structural parameters of the pin fins inside the liquid-cooling plate on its heat dissipation performance and pressure drop characteristics.A theoretical basis is provided for the design of liquid-cooling plates in power batteries and the optimization of structural parameters.
基金supported by a grant from The National Natural Science Foundation of China(32000997)。
文摘Spores and pollen,as ubiquitous organisms found in nature,possess a remarkable core-shell structure and intricate surface morphology.These tiny particles are notable for their dimensional uniformity,sustainable utilization,environmental friendliness,porosity,amphiphilicity,and strong adhesive properties.In addition,they display excellent biocompatibility and biodegradability,which significantly enhances the stability and targeting of drugs within the body.Spores and pollen can be extracted using methods such as acidic solutions,alkaline solutions,or enzyme treatments to obtain sporopollenin,which is an extremely resilient and chemically inert complex biopolymer.The sporopollenin extracted through this process removes the original bioactive substances,such as cell nuclei,enzymes,and DNA,providing greater drug loading capacity and containing no potential allergens or immunogens,thus further enhancing its drug loading capacity and improving safety in therapeutic applications.Due to these beneficial attributes,spores,pollen and sporopollenin have gained widespread use in a variety of drug delivery systems,such as targeted delivery,sustained drug delivery,toxicity mitigation,flavor masking,vaccine delivery,delivery of labile substances,and other applications.This review introduces the types of natural spores and pollen commonly used in drug delivery systems,including their main components,common effects,and uses in drug delivery systems,and so on.It subsequently summarizes novel optimization methods in their processing,such as physical treatment,surface modification,and chemical modification,which enable higher drug loading efficiency,stability,and targeting,among other benefits.Additionally,this paper reviews the research progress and applications of natural spores,pollen,and sporopollenin in drug delivery systems,while also touching on some innovative research content,such as novel nanomotor microcarriers developed based on pollen.Based on these research findings,we further elaborate on the advantages of spores,pollen,and sporopollenin in drug delivery systems.For example,they have high stability and drug loading capacity,good adhesion,excellent targeting,and are easy to modify functionally.Currently,they show promising prospects in the fields of targeted drug delivery,sustained-release drug delivery,as well as the delivery of drugs that are effective but slightly toxic,and are often used in research on the treatment of diseases such as cancer and inflammation.We have also highlighted the challenges they face in various applications and identified some issues that need to be addressed,including difficulties in largescale production,the need to improve extraction and purification processes,and the existence of a low but still noteworthy risk of allergies,in order to fully leverage their potential in drug delivery applications.According to current research,although spores,pollen,and sporopollenin face some unresolved issues in clinical drug delivery,they still have great potential overall and are expected to become a new generation of green drug delivery platforms.In the future,further research into their unique physical and chemical properties and structural characteristics will help develop more efficient and stable drug delivery systems to meet diverse treatment needs.We believe that continued exploration of natural spores,pollen,and sporopollenin will drive this emerging field to achieve continuous breakthroughs and progress,ultimately making an important contribution to the cause of human health.
基金financially supported by the Young Scientists Fund of National Natural Science Foundation of China(Grant No.52303106)Research Grants Council of Hong Kong SAR(16200720)+3 种基金Environment and Conservation Fund of Hong Kong SAR(Project No.21/2022)Research Institute of Sports Science and Technology(Project No.P0043535)Research Institute of Advanced Manufacturing(Project No.P0046125)the start-up fund for new recruits of Poly U(Project No.P0038855 and P0038858)。
文摘Hygroscopic hydrogel is a promising evaporativecooling material for high-power passive daytime cooling with water self-regeneration.However,undesired solar and environmental heating makes it a challenge to maintain sub-ambient daytime cooling.While different strategies have been developed to mitigate heat gains,they inevitably sacrifice the evaporation and water regeneration due to highly coupled thermal and vapor transport.Here,an anisotropic synergistically performed insulation-radiation-evaporation(ASPIRE)cooler is developed by leveraging a dual-alignment structure both internal and external to the hydrogel for coordinated thermal and water transport.The ASPIRE cooler achieves an impressive average sub-ambient cooling temperature of~8.2℃ and a remarkable peak cooling power of 311 W m^(-2)under direct sunlight.Further examining the cooling mechanism reveals that the ASPIRE cooler reduces the solar and environmental heat gains without comprising the evaporation.Moreover,self-sustained multi-day cooling is possible with water self-regeneration at night under both clear and cloudy days.The synergistic design provides new insights toward high-power,sustainable,and all-weather passive cooling applications.
基金supported by the Australia Research Council through the Discovery Project scheme(DP190103186 and DP220100603)the Industrial Transformation Training Centres scheme(IC180100005)+5 种基金the Future Fellowship scheme(FT210100806)the Future Fellowship scheme(FT220100559)the Discovery Early Career Researcher Award scheme(DE230100383)the Shenzhen Science and Technology Program(GJHZ20240218113407015)the Natural Science Foundation of Shandong Province(ZR2021ME162)the Key Research and Development Program of Shandong Province,China(2022SFGC0501).
文摘Radiative cooling is an environmentally friendly,passive cooling technology that operates without energy consumption.Current research primarily focuses on optimizing the optical properties of radiative cooling films to enhance their cooling performance.In practical applications,thermal contact between the radiative cooling film and the object significantly influences the ultimate cooling performance.However,achieving optimal thermal contact has received limited attention.In this study,we propose and experimentally demonstrate a high-power,flexible,and magnetically attachable and detachable radiative cooling film.This film consists of polymer metasurface structures on a flexible magnetic layer.The monolithic design allows for convenient attachment to and detachment from steel or iron surfaces,ensuring optimal thermal contact with minimal thermal resistance and uniform temperature distribution.Our magnetic radiative cooling film exhibits superior cooling performance compared to non-magnetic alternatives.It can reduce the temperature of stainless-steel plates under sunlight by 15.2℃,which is 3.6℃ more than that achieved by non-magnetic radiative cooling films.The radiative cooling power can reach 259W·m^(-2) at a working temperature of 70℃.Unlike other commonly used attachment methods,such as thermal grease or one-off tape,our approach allows for detachment and reusability of the cooling film according to practical needs.This method offers great simplicity,flexibility,and cost-effectiveness,making it promising for broad applications,particularly on non-horizontal irregular surfaces previously considered challenging.
