AIM: To evaluate human pancreatic carcinoma cell line(PANC-1) cells apoptosis and Bcl-2 and Bax expression induced by Yin Chen Hao Decoction(YCHD).METHODS: The cell growth inhibitory rate was determined by MTT assay. ...AIM: To evaluate human pancreatic carcinoma cell line(PANC-1) cells apoptosis and Bcl-2 and Bax expression induced by Yin Chen Hao Decoction(YCHD).METHODS: The cell growth inhibitory rate was determined by MTT assay. Apoptosis of PANC-1 cells before and after treatment with YCHD was determined by TUNEL staining. Expression of the apoptosisassociated genes, Bcl-2 and Bax, was detected by immunohistochemical staining and reverse transcription-PCR.RESULTS: YCHD inhibited the growth of PANC-1 cells. Following treatment with YCHD for 24-96 h, the apoptotic rate of PANC-1 cells increased with time. In addition, the positive rate of Bcl-2 protein expression decreased in a time-dependent manner, whereas the positive rate of Bax protein expression increased in a time-dependent manner. Following treatment of with YCHD for 24-96 h, expression of BAX m RNA increased gradually and BCL-2 m RNA reduced gradually with time.CONCLUSION: YCHD induces apoptosis of PANC-1 cells mediated in part via up-regulation of BAX and down-regulation of BCL-2.展开更多
Thermoelectric materials,enabling the directing conversion between heat and electricity,are one of the promising candidates for overcoming environmental pollution and the upcoming energy shortage caused by the over-co...Thermoelectric materials,enabling the directing conversion between heat and electricity,are one of the promising candidates for overcoming environmental pollution and the upcoming energy shortage caused by the over-consumption of fossil fuels.Bi2Te3-based alloys are the classical thermoelectric materials working near room temperature.Due to the intensive theoretical investigations and experimental demonstrations,significant progress has been achieved to enhance the thermoelectric performance of Bi2Te3-based thermoelectric materials.In this review,we first explored the fundamentals of thermoelectric effect and derived the equations for thermoelectric properties.On this basis,we studied the effect of material parameters on thermoelectric properties.Then,we analyzed the features of Bi2Te3-based thermoelectric materials,including the lattice defects,anisotropic behavior and the strong bipolar conduction at relatively high temperature.Then we accordingly summarized the strategies for enhancing the thermoelectric performance,including point defect engineering,texture alignment,and band gap enlargement.Moreover,we highlighted the progress in decreasing thermal conductivity using nanostructures fabricated by solution grown method,ball milling,and melt spinning.Lastly,we employed modeling analysis to uncover the principles of anisotropy behavior and the achieved enhancement in Bi2Te3,which will enlighten the enhancement of thermoelectric performance in broader materials展开更多
Ceramic balls represent a new type of damaging element,and studies on their damaging power of composite armor are required for a comprehensive evaluation of the effectiveness of various types of weapons.The goal of th...Ceramic balls represent a new type of damaging element,and studies on their damaging power of composite armor are required for a comprehensive evaluation of the effectiveness of various types of weapons.The goal of this study was to determine the impact ofφ7 mm toughened Al2 O3 ceramic balls on a composite ceramic/metal armor.The influences of the ceramic panel and the thickness of the metal backing material on the destroying power of the ceramic balls were first determined.Based on the agreement between numerical simulation,experimental results,and calculation models of the target plate resistance,the response mechanism of the ceramic balls was further analyzed.The results indicate that for a back plate of Q235 steel,with an increasing thickness of the ceramic panel,the piercing speed limit of the ceramic balls gradually increases and the diameter of the out-going hole on the metal back decreases.Different conditions were tested to assess the effects on the piercing speed,the diameter of the out-going hole,the micro-element stress,and the integrity of the recovered ceramic bowl.展开更多
The dependence of tumor growth on neovascularization has become an important aspect of cancer biology.Tumor angiogenesis is one of the key mechanisms of tumorigenesis,growth and metastasis.The key events involved in t...The dependence of tumor growth on neovascularization has become an important aspect of cancer biology.Tumor angiogenesis is one of the key mechanisms of tumorigenesis,growth and metastasis.The key events involved in this process are endothelial cell proliferation,migration,and vascular formation.Recent studies have revealed the importance of tumor-associated endothelial cells(TECs)in the development and progression of colorectal cancer(CRC),including epithelial proliferation,stem cell maintenance,angiogenesis,and immune remodeling.Decades of research have identified that the molecular basis of tumor angiogenesis includes vascular endothelial growth factors(VEGFs)and their receptor family,which are the main targets of antiangiogenesis therapy.VEGFs and their receptors play key roles in the pathology of angiogenesis,and their overexpression indicates poor prognosis in CRC.This article reviews the characteristics of the tumor vasculature and the role of TECs in different stages of CRC and immune remodeling.We also discuss the biological effects of VEGFs and their receptor family as angiogenesis regulators and emphasize the clinical implications of TECs in clinical treatment.展开更多
In order to improve the penetration of projectiles into ceramic composite armors,the nose of 30 mm standard projectile was replaced by a toughened ceramic nose,and the performance of ceramic-nose projectiles penetrati...In order to improve the penetration of projectiles into ceramic composite armors,the nose of 30 mm standard projectile was replaced by a toughened ceramic nose,and the performance of ceramic-nose projectiles penetrating into ceramic/A3 steel composite targets has been experimentally researched.According to impact dynamics theory,,the performances of 30 mm ceramic-nose projectile and 30 mm standard projectile penetrating into the ceramic/A3 steel composite targets were analyzed and compared using DOP method,especially focusing on the effects made by different nose structures and materials.The aperture and depth of perforation of projectile into the armor plates as well as the residual mass of bullet core under the same conditions were comparatively analyzed.A numerical simulation was built and computed by ANSYS/LS-DYNA.Based on the simulated results,the penetration performance was further analyzed in terms of the residual mass of bullet core.The results show that the ceramic nose has a great effect on the protection of bullet core.展开更多
In order to study the performance of ceramic composite projectile penetrating into ceramic composite target,the contrast test and numerical simulations of the penetration of standard projectile and the ceramic composi...In order to study the performance of ceramic composite projectile penetrating into ceramic composite target,the contrast test and numerical simulations of the penetration of standard projectile and the ceramic composite projectile into a ceramic composite target were conducted.The results show that the penetration performance of ceramic composite projectile is obvious superior to that of standard projectile for ceramic composite target.The ceramic nose of ceramic composite projectile fully destroys the ceramic panels anterior to its following armor-piercing projectile body,thus maintaining the penetration ability of the following armor-piercing projectile body.展开更多
Normal cells mainly rely on oxidative phosphorylation as an effective energy source in the presence of oxygen.In contrast,most cancer cells use less efficient glycolysis to produce ATP and essential biomolecules.Cance...Normal cells mainly rely on oxidative phosphorylation as an effective energy source in the presence of oxygen.In contrast,most cancer cells use less efficient glycolysis to produce ATP and essential biomolecules.Cancer cells gain the characteristics of metabolic adaptation by reprogramming their metabolic mechanisms to meet the needs of rapid tumor growth.A subset of cancer cells with stem characteristics and the ability to regenerate exist throughout the tumor and are therefore called cancer stem cells(CSCs).New evidence indicates that CSCs have different metabolic phenotypes compared with differentiated cancer cells.CSCs can dynamically transform their metabolic state to favor glycolysis or oxidative metabolism.The mechanism of the metabolic plasticity of CSCs has not been fully elucidated,and existing evidence indicates that the metabolic phenotype of cancer cells is closely related to the tumor microenvironment.Targeting CSC metabolism may provide new and effective methods for the treatment of tumors.In this review,we summarize the metabolic characteristics of cancer cells and CSCs and the mechanisms of the metabolic interplay between the tumor microenvironment and CSCs,and discuss the clinical implications of targeting CSC metabolism.展开更多
Thermoelectric materials and devices enable direct conversion between heat and electricity,holding potential applications in thermoelectric power generation,localized cooling,and electronic thermal management[1].Howev...Thermoelectric materials and devices enable direct conversion between heat and electricity,holding potential applications in thermoelectric power generation,localized cooling,and electronic thermal management[1].However,despite widespread applications,thermoelectric technology remains constrained by material performance[2].展开更多
Owing to the capability of the conversion between thermal energy and electrical energy and their advantages of light weight,compactness,noise-free operation,and precision reliability,wearable thermoelectrics show grea...Owing to the capability of the conversion between thermal energy and electrical energy and their advantages of light weight,compactness,noise-free operation,and precision reliability,wearable thermoelectrics show great potential for diverse applications.Among them,weavable thermoelectrics,a subclass with inherent flexibility,wearability,and operability,find utility in harnessing waste heat from irregular heat sources.Given the rapid advancements in this field,a timely review is essential to consolidate the progress and challenge.Here,we provide an overview of the state of weavable thermoelectric materials and devices in wearable smart textiles,encompassing mechanisms,materials,fabrications,device structures,and applications from recent advancements,challenges,and prospects.This review can serve as a valuable reference for researchers in the field of flexible wearable thermoelectric materials and devices and their applications.展开更多
Developing high-performance poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)sig-nificantly widens the practical applications of flexible organic thermoelectric devices,while the water-based co-solve...Developing high-performance poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)sig-nificantly widens the practical applications of flexible organic thermoelectric devices,while the water-based co-solvent dopants and/or post-treatments are still rarely studied so far.Here,we develop a one-step post-treatment to improve the power factor of PEDOT:PSS films by using a water-based solution,which is composed of co-solvent(polar solvent dimethylacetamide(DMAC)and deionized water)and organic reducing agent L-ascorbic acid(LAA).The 80 vol.%DMAC solution significantly boosts the room-temperature electrical conductivity of the films from 5 to 964 S cm^(−1),while the Seebeck coefficient can be further enhanced from 18.7 to 25μV K−1 by treating with 0.5 mol L−1 LAA,contributing to a sig-nificantly improved power factor of 55.3μW m^(−1)K^(−2).The boosted electrical conductivity is ascribed to the separated PEDOT and PSS phases triggered by the high dielectric constant and polarity of DMAC;while the improved Seebeck coefficient is attributed to the reduced oxidation degree of PEDOT from the reducing agent LAA,both confirmed by the comprehensive structural and morphological characteri-zations.Furthermore,a maximum power factor of 64.4μW m^(−1)K^(−2)can be achieved at 360 K and the observed temperature-dependent electrical transport behavior can be well explained by the Mott variable range hopping model.Besides,a flexible thermoelectric device,assembled by the as-fabricated PEDOT:PSS films,exhibits a maximum output power of∼23 nW at a temperature difference of 25 K,indicating the potential for applying to low-grade wearable electronics.展开更多
By effectively converting waste heat into electricity,thermoelectric materials and devices can provide an alternative approach to tackle the energy crisis.Amongst thermoelectric materials,bismuth telluride(Bi_(2)Te_(3...By effectively converting waste heat into electricity,thermoelectric materials and devices can provide an alternative approach to tackle the energy crisis.Amongst thermoelectric materials,bismuth telluride(Bi_(2)Te_(3))and its derivatives exhibit high figure of merit ZT values in the near-room-temperature region and show great potential for application in thermoelectric devices.Considering the rapid development of Bi_(2)Te_(3)-based thermoelectric materials and their devices in the last few years,a short and systematic review is much needed.Here,we sum-marize the novel designs,properties,and applications of Bi_(2)Te_(3)-based thermoelectric devices in different contexts,including wearable,portable,implantable,and cross-disciplinary applications.The challenges and outlook for Bi_(2)Te_(3)-based thermoelectric devices are also considered.This work will guide the future development of Bi_(2)Te_(3)-based thermoelectric devices that target broader and more practical applications.展开更多
Heavy rare-earth element doping can effectively strengthen phonon scattering,suppress the lattice thermal conductivity,and enhance the overall thermoelectric performance of GeTe.However,the large electronegativity dif...Heavy rare-earth element doping can effectively strengthen phonon scattering,suppress the lattice thermal conductivity,and enhance the overall thermoelectric performance of GeTe.However,the large electronegativity difference between rare-earth elements(such as La,Eu,and Gd)and Ge refrains the doping limit of rare-earth elements below 1 mol.%in GeTe.Here,compared with other rare earth elements,Lu was found to have a relatively small radius and electronegativity difference with Ge,which can induce a high doping level in GeTe.The result shows that Lu doping effectively reduces the lattice thermal conductivity from 0.77 W^(−1) m K^(−1) of GeTe to 0.35 W m^(−1) K^(−1) of Ge_(0.98)Lu_(0.02)Te at 673 K,and further induces a high zT value of 1.5 in Ge_(0.98)Lu_(0.02)Te at 673 K.Extra Sb alloying optimizes the carrier concentration from 1.02×10^(21) cm^(−3) of Ge_(0.98)Lu_(0.02)Te to 1.77×10^(20) cm^(−3) of Ge0.90Lu0.02Sb0.08Te,which results in a reasonable power factor of 33.82μW cm^(−1) K^(−2) and a low electrical thermal conductivity of 0.75 W m^(−1) K^(−1) at 673 K in Ge_(0.90)Lu_(0.02)Sb_(0.08)Te.Correspondingly,a peak zT of 1.75 at 673 K and an average zT of 0.92 within the temperature range of 303–723 K are obtained in Ge_(0.9)Lu_(0.02)Sb_(0.08)Te.This study indicates that Lu and Sb co-doping can effectively boost the thermoelectric performance of GeTe-based thermoelectric materials.展开更多
OBJECTIVE： To treat patients with vascular mild cognitive impairment （VMCI） using traditional Chinese medicine （TCM）, it is necessary to classify the patients into TCM syndrome types and to apply different treatm...OBJECTIVE： To treat patients with vascular mild cognitive impairment （VMCI） using traditional Chinese medicine （TCM）, it is necessary to classify the patients into TCM syndrome types and to apply different treatments to different types. In this paper, we investigate how to properly carry out the classification for patients with VMCI aged 50 or above using a novel data-driven method known as latent tree analysis （LTA）. METHOD： A cross-sectional survey on VMCI was carried out in several regions in Northern China between February 2008 and February 2012 which resulted in a data set that involves 803 patients and 93 symptoms. LTA was performed on the data to reveal symptom co-occurrence patterns, and the patients were partitioned into clusters in multiple ways based on the patterns. The patient clusters were matched up with syndrome types, and population statistics of the clusters are used to quantify the syndrome types and to establish classification rules. RESULTS： Eight syndrome types are identified： Qi deficiency, Qi stagnation, Blood deficiency, Blood stasis, Phlegm-dampness, Fire-heat, Yang deficiency, and Yin deficiency. The prevalence and symptom occurrence characteristics of each syndrome type are determined. Quantitative classification rules are established for determining whether a patient belongs to each of the syndrome types. CONCLUSION： A solution for the TCM syndrome classification problem for patients with VMCI and aged 50 or above is established based on the LTA of unlabeled symptom survey data. The results can be used as a reference in clinic practice to improve the quality of syndrome differentiation and to reduce diagnosis variances across physicians. They can also be used for patient selection in research projects aimed at finding biomarkers for the syndrome types and in randomized control trials aimed at determining the efficacy of TCM treatments of VMCI.展开更多
We study the strategies in feature selection with sparse support vector machine （SVM）. Recently, the socalled Lp-SVM （0 〈 p 〈 1） has attracted much attention because it can encourage better sparsity than the wid...We study the strategies in feature selection with sparse support vector machine （SVM）. Recently, the socalled Lp-SVM （0 〈 p 〈 1） has attracted much attention because it can encourage better sparsity than the widely used L1-SVM. However, Lp-SVM is a non-convex and non-Lipschitz optimization problem. Solving this problem numerically is challenging. In this paper, we reformulate the Lp-SVM into an optimization model with linear objective function and smooth constraints （LOSC-SVM） so that it can be solved by numerical methods for smooth constrained optimization. Our numerical experiments on artificial datasets show that LOSC-SVM （0 〈 p 〈 1） can improve the classification performance in both feature selection and classification by choosing a suitable parameter p. We also apply it to some real-life datasets and experimental results show that it is superior to L1-SVM.展开更多
Interface engineering has been regarded as an effective strategy to manipulate the thermoelectric performance of materials.Here,we use a facile chemical electroless plating and a spark plasma sintering process to fabr...Interface engineering has been regarded as an effective strategy to manipulate the thermoelectric performance of materials.Here,we use a facile chemical electroless plating and a spark plasma sintering process to fabricate Ag-plated SnTe bulk.After sintering,a small amount of plated Ag can be doped into SnTe to suppress the Sn vacancies and the others form Ag precipitates with a size distribution from nanoscale to microscale,which introduces Ag/SnTe interfaces to enhance the Seebeck coefficient via energy filtering effect.Simultaneously,these structures result in strong scattering to reach a low lattice thermal conductivity of-0.62 W·m^(–1)·K^(–1).Consequently,a maximum figure of merit(zT)of-0.67 at 823 K is achieved in 2 wt%Ag-plated SnTe,which is-60%higher than that of pristine SnTe.Moreover,the microhardness indentation test results show that the mean microhardness of 2 wt%Ag-plated SnTe is HV 64.26,which is much higher than that of pristine SnTe,indicating that Ag electroless plating can improve the mechanical properties of SnTe.This work has provided a facile and eco-friendly method to realize the interface engineering for manipulating the thermoelectric and mechanical properties of SnTe.展开更多
基金Supported by Traditional Chinese Medicine Administration of Zhejiang Province,China,No.2014ZA068
文摘AIM: To evaluate human pancreatic carcinoma cell line(PANC-1) cells apoptosis and Bcl-2 and Bax expression induced by Yin Chen Hao Decoction(YCHD).METHODS: The cell growth inhibitory rate was determined by MTT assay. Apoptosis of PANC-1 cells before and after treatment with YCHD was determined by TUNEL staining. Expression of the apoptosisassociated genes, Bcl-2 and Bax, was detected by immunohistochemical staining and reverse transcription-PCR.RESULTS: YCHD inhibited the growth of PANC-1 cells. Following treatment with YCHD for 24-96 h, the apoptotic rate of PANC-1 cells increased with time. In addition, the positive rate of Bcl-2 protein expression decreased in a time-dependent manner, whereas the positive rate of Bax protein expression increased in a time-dependent manner. Following treatment of with YCHD for 24-96 h, expression of BAX m RNA increased gradually and BCL-2 m RNA reduced gradually with time.CONCLUSION: YCHD induces apoptosis of PANC-1 cells mediated in part via up-regulation of BAX and down-regulation of BCL-2.
基金supported by the National Natural Science Foundation of China(No.91845109,No.21872169,No.22102209,No.22172190)the support from Jiangsu Planned Projects for Postdoctoral Research Funds(No.2021K226B).
基金the financial supports from the Natural Science Foundation of Hunan Province, China (No. 2018JJ2365)the Outstanding Youth Scientific Research Project of Hunan Education Department, China (No. 20B533)+3 种基金the Key Scientific Research Project of Hunan Provincial Department of Education, China (No. 20A455)the Science and Technology Innovation Program of Hunan Province, China (No. 2020RC1011)the Graduate Scientific Research Innovation Project of Hunan Province, China (No. CX20211280)the Science and Technology Innovation Leading Plan of High Tech Industry in Hunan Province, China (No. 2020GK2033)。
基金Project supported by the Australian Research CouncilZhi-Gang Chen thanks the USQ start-up grantstrategic research grant
文摘Thermoelectric materials,enabling the directing conversion between heat and electricity,are one of the promising candidates for overcoming environmental pollution and the upcoming energy shortage caused by the over-consumption of fossil fuels.Bi2Te3-based alloys are the classical thermoelectric materials working near room temperature.Due to the intensive theoretical investigations and experimental demonstrations,significant progress has been achieved to enhance the thermoelectric performance of Bi2Te3-based thermoelectric materials.In this review,we first explored the fundamentals of thermoelectric effect and derived the equations for thermoelectric properties.On this basis,we studied the effect of material parameters on thermoelectric properties.Then,we analyzed the features of Bi2Te3-based thermoelectric materials,including the lattice defects,anisotropic behavior and the strong bipolar conduction at relatively high temperature.Then we accordingly summarized the strategies for enhancing the thermoelectric performance,including point defect engineering,texture alignment,and band gap enlargement.Moreover,we highlighted the progress in decreasing thermal conductivity using nanostructures fabricated by solution grown method,ball milling,and melt spinning.Lastly,we employed modeling analysis to uncover the principles of anisotropy behavior and the achieved enhancement in Bi2Te3,which will enlighten the enhancement of thermoelectric performance in broader materials
文摘Ceramic balls represent a new type of damaging element,and studies on their damaging power of composite armor are required for a comprehensive evaluation of the effectiveness of various types of weapons.The goal of this study was to determine the impact ofφ7 mm toughened Al2 O3 ceramic balls on a composite ceramic/metal armor.The influences of the ceramic panel and the thickness of the metal backing material on the destroying power of the ceramic balls were first determined.Based on the agreement between numerical simulation,experimental results,and calculation models of the target plate resistance,the response mechanism of the ceramic balls was further analyzed.The results indicate that for a back plate of Q235 steel,with an increasing thickness of the ceramic panel,the piercing speed limit of the ceramic balls gradually increases and the diameter of the out-going hole on the metal back decreases.Different conditions were tested to assess the effects on the piercing speed,the diameter of the out-going hole,the micro-element stress,and the integrity of the recovered ceramic bowl.
基金Supported by the National Natural Science Foundation of China,No.81502564,No.81972598the Natural Science Foundation of Zhejiang Province,No.LY16H160018,No.LY18H160001the scholarship from China Scholarship Council(CSC)under the Grant CSC,No.201706325003
文摘The dependence of tumor growth on neovascularization has become an important aspect of cancer biology.Tumor angiogenesis is one of the key mechanisms of tumorigenesis,growth and metastasis.The key events involved in this process are endothelial cell proliferation,migration,and vascular formation.Recent studies have revealed the importance of tumor-associated endothelial cells(TECs)in the development and progression of colorectal cancer(CRC),including epithelial proliferation,stem cell maintenance,angiogenesis,and immune remodeling.Decades of research have identified that the molecular basis of tumor angiogenesis includes vascular endothelial growth factors(VEGFs)and their receptor family,which are the main targets of antiangiogenesis therapy.VEGFs and their receptors play key roles in the pathology of angiogenesis,and their overexpression indicates poor prognosis in CRC.This article reviews the characteristics of the tumor vasculature and the role of TECs in different stages of CRC and immune remodeling.We also discuss the biological effects of VEGFs and their receptor family as angiogenesis regulators and emphasize the clinical implications of TECs in clinical treatment.
文摘In order to improve the penetration of projectiles into ceramic composite armors,the nose of 30 mm standard projectile was replaced by a toughened ceramic nose,and the performance of ceramic-nose projectiles penetrating into ceramic/A3 steel composite targets has been experimentally researched.According to impact dynamics theory,,the performances of 30 mm ceramic-nose projectile and 30 mm standard projectile penetrating into the ceramic/A3 steel composite targets were analyzed and compared using DOP method,especially focusing on the effects made by different nose structures and materials.The aperture and depth of perforation of projectile into the armor plates as well as the residual mass of bullet core under the same conditions were comparatively analyzed.A numerical simulation was built and computed by ANSYS/LS-DYNA.Based on the simulated results,the penetration performance was further analyzed in terms of the residual mass of bullet core.The results show that the ceramic nose has a great effect on the protection of bullet core.
文摘In order to study the performance of ceramic composite projectile penetrating into ceramic composite target,the contrast test and numerical simulations of the penetration of standard projectile and the ceramic composite projectile into a ceramic composite target were conducted.The results show that the penetration performance of ceramic composite projectile is obvious superior to that of standard projectile for ceramic composite target.The ceramic nose of ceramic composite projectile fully destroys the ceramic panels anterior to its following armor-piercing projectile body,thus maintaining the penetration ability of the following armor-piercing projectile body.
基金National Natural Science Foundation of China,No.81502564 and No.81972598the Natural Science Foundation of Zhejiang Province,No.LY19H160004.
文摘Normal cells mainly rely on oxidative phosphorylation as an effective energy source in the presence of oxygen.In contrast,most cancer cells use less efficient glycolysis to produce ATP and essential biomolecules.Cancer cells gain the characteristics of metabolic adaptation by reprogramming their metabolic mechanisms to meet the needs of rapid tumor growth.A subset of cancer cells with stem characteristics and the ability to regenerate exist throughout the tumor and are therefore called cancer stem cells(CSCs).New evidence indicates that CSCs have different metabolic phenotypes compared with differentiated cancer cells.CSCs can dynamically transform their metabolic state to favor glycolysis or oxidative metabolism.The mechanism of the metabolic plasticity of CSCs has not been fully elucidated,and existing evidence indicates that the metabolic phenotype of cancer cells is closely related to the tumor microenvironment.Targeting CSC metabolism may provide new and effective methods for the treatment of tumors.In this review,we summarize the metabolic characteristics of cancer cells and CSCs and the mechanisms of the metabolic interplay between the tumor microenvironment and CSCs,and discuss the clinical implications of targeting CSC metabolism.
文摘Thermoelectric materials and devices enable direct conversion between heat and electricity,holding potential applications in thermoelectric power generation,localized cooling,and electronic thermal management[1].However,despite widespread applications,thermoelectric technology remains constrained by material performance[2].
基金supported by the Australian Research Council and QUT Capacity Building Professor ProgramL Q F acknowledges the financial support from the National Natural Science Foundation of China(No.52272040).
文摘Owing to the capability of the conversion between thermal energy and electrical energy and their advantages of light weight,compactness,noise-free operation,and precision reliability,wearable thermoelectrics show great potential for diverse applications.Among them,weavable thermoelectrics,a subclass with inherent flexibility,wearability,and operability,find utility in harnessing waste heat from irregular heat sources.Given the rapid advancements in this field,a timely review is essential to consolidate the progress and challenge.Here,we provide an overview of the state of weavable thermoelectric materials and devices in wearable smart textiles,encompassing mechanisms,materials,fabrications,device structures,and applications from recent advancements,challenges,and prospects.This review can serve as a valuable reference for researchers in the field of flexible wearable thermoelectric materials and devices and their applications.
基金supported by the National Natural Science Foundation of China(Grant No.51802181)Natural Science Basic Research Program of Shaanxi(Grant No.2022JZ-31)+3 种基金Young Talent fund of University Association for Science and Technology in Shaanxi,China(Grant No.20210411)China Postdoctoral Sci-ence Foundation(Grant No.2021M692621)the Foundation of Shaanxi University of Science&Technology(Grant No.2017GBJ-03)ZGC thanks the financial support from the Australian Research Council,QUT capacity building professor program,and HBIS-UQ In-novation center for Sustainable Steel(ICSS)project.
文摘Developing high-performance poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)sig-nificantly widens the practical applications of flexible organic thermoelectric devices,while the water-based co-solvent dopants and/or post-treatments are still rarely studied so far.Here,we develop a one-step post-treatment to improve the power factor of PEDOT:PSS films by using a water-based solution,which is composed of co-solvent(polar solvent dimethylacetamide(DMAC)and deionized water)and organic reducing agent L-ascorbic acid(LAA).The 80 vol.%DMAC solution significantly boosts the room-temperature electrical conductivity of the films from 5 to 964 S cm^(−1),while the Seebeck coefficient can be further enhanced from 18.7 to 25μV K−1 by treating with 0.5 mol L−1 LAA,contributing to a sig-nificantly improved power factor of 55.3μW m^(−1)K^(−2).The boosted electrical conductivity is ascribed to the separated PEDOT and PSS phases triggered by the high dielectric constant and polarity of DMAC;while the improved Seebeck coefficient is attributed to the reduced oxidation degree of PEDOT from the reducing agent LAA,both confirmed by the comprehensive structural and morphological characteri-zations.Furthermore,a maximum power factor of 64.4μW m^(−1)K^(−2)can be achieved at 360 K and the observed temperature-dependent electrical transport behavior can be well explained by the Mott variable range hopping model.Besides,a flexible thermoelectric device,assembled by the as-fabricated PEDOT:PSS films,exhibits a maximum output power of∼23 nW at a temperature difference of 25 K,indicating the potential for applying to low-grade wearable electronics.
基金This study was financially supported by the Australian Research Council,HBIS-UQ Imnovation Centre for Sustainable Steel project,and QUT Capacity Building Professor ProgramNational Computational Infrastructure supported by the Australian Govemment is acknowledged for providing computation resources and services.
文摘By effectively converting waste heat into electricity,thermoelectric materials and devices can provide an alternative approach to tackle the energy crisis.Amongst thermoelectric materials,bismuth telluride(Bi_(2)Te_(3))and its derivatives exhibit high figure of merit ZT values in the near-room-temperature region and show great potential for application in thermoelectric devices.Considering the rapid development of Bi_(2)Te_(3)-based thermoelectric materials and their devices in the last few years,a short and systematic review is much needed.Here,we sum-marize the novel designs,properties,and applications of Bi_(2)Te_(3)-based thermoelectric devices in different contexts,including wearable,portable,implantable,and cross-disciplinary applications.The challenges and outlook for Bi_(2)Te_(3)-based thermoelectric devices are also considered.This work will guide the future development of Bi_(2)Te_(3)-based thermoelectric devices that target broader and more practical applications.
基金supported by the Australian Research Council,the Innovation centre for Sustainable Steel project,and the QUT capacity building professor program.K.Guo thanks the support of the National Key Research and Development Program of China(No.2018YFA0702100)。
文摘Heavy rare-earth element doping can effectively strengthen phonon scattering,suppress the lattice thermal conductivity,and enhance the overall thermoelectric performance of GeTe.However,the large electronegativity difference between rare-earth elements(such as La,Eu,and Gd)and Ge refrains the doping limit of rare-earth elements below 1 mol.%in GeTe.Here,compared with other rare earth elements,Lu was found to have a relatively small radius and electronegativity difference with Ge,which can induce a high doping level in GeTe.The result shows that Lu doping effectively reduces the lattice thermal conductivity from 0.77 W^(−1) m K^(−1) of GeTe to 0.35 W m^(−1) K^(−1) of Ge_(0.98)Lu_(0.02)Te at 673 K,and further induces a high zT value of 1.5 in Ge_(0.98)Lu_(0.02)Te at 673 K.Extra Sb alloying optimizes the carrier concentration from 1.02×10^(21) cm^(−3) of Ge_(0.98)Lu_(0.02)Te to 1.77×10^(20) cm^(−3) of Ge0.90Lu0.02Sb0.08Te,which results in a reasonable power factor of 33.82μW cm^(−1) K^(−2) and a low electrical thermal conductivity of 0.75 W m^(−1) K^(−1) at 673 K in Ge_(0.90)Lu_(0.02)Sb_(0.08)Te.Correspondingly,a peak zT of 1.75 at 673 K and an average zT of 0.92 within the temperature range of 303–723 K are obtained in Ge_(0.9)Lu_(0.02)Sb_(0.08)Te.This study indicates that Lu and Sb co-doping can effectively boost the thermoelectric performance of GeTe-based thermoelectric materials.
基金supported by the Hong Kong Research Grants Council under grant NO.16202515 and 16212516Guangzhou HKUST Fok Ying Tung Research Institute,China Ministry of Science and Technology TCM Special Research Projects Program under grant No.200807011,No.201007002 and No.201407001-8+2 种基金Beijing Science and Technology Program under grant No.Z111107056811040Beijing New Medical Discipline Development Program under grant No.XK100270569Project of Beijing University of Chinese Medicine under grant No.2011-CXTD-23
文摘OBJECTIVE： To treat patients with vascular mild cognitive impairment （VMCI） using traditional Chinese medicine （TCM）, it is necessary to classify the patients into TCM syndrome types and to apply different treatments to different types. In this paper, we investigate how to properly carry out the classification for patients with VMCI aged 50 or above using a novel data-driven method known as latent tree analysis （LTA）. METHOD： A cross-sectional survey on VMCI was carried out in several regions in Northern China between February 2008 and February 2012 which resulted in a data set that involves 803 patients and 93 symptoms. LTA was performed on the data to reveal symptom co-occurrence patterns, and the patients were partitioned into clusters in multiple ways based on the patterns. The patient clusters were matched up with syndrome types, and population statistics of the clusters are used to quantify the syndrome types and to establish classification rules. RESULTS： Eight syndrome types are identified： Qi deficiency, Qi stagnation, Blood deficiency, Blood stasis, Phlegm-dampness, Fire-heat, Yang deficiency, and Yin deficiency. The prevalence and symptom occurrence characteristics of each syndrome type are determined. Quantitative classification rules are established for determining whether a patient belongs to each of the syndrome types. CONCLUSION： A solution for the TCM syndrome classification problem for patients with VMCI and aged 50 or above is established based on the LTA of unlabeled symptom survey data. The results can be used as a reference in clinic practice to improve the quality of syndrome differentiation and to reduce diagnosis variances across physicians. They can also be used for patient selection in research projects aimed at finding biomarkers for the syndrome types and in randomized control trials aimed at determining the efficacy of TCM treatments of VMCI.
基金This work is supported in part by the National Natural Science Foundation of China under Grant Nos. 61502159, 61379057, 11101081, and 11271069, and the Research Foundation of Central South University of China under Grant No. 2014JSJJ019.
文摘We study the strategies in feature selection with sparse support vector machine （SVM）. Recently, the socalled Lp-SVM （0 〈 p 〈 1） has attracted much attention because it can encourage better sparsity than the widely used L1-SVM. However, Lp-SVM is a non-convex and non-Lipschitz optimization problem. Solving this problem numerically is challenging. In this paper, we reformulate the Lp-SVM into an optimization model with linear objective function and smooth constraints （LOSC-SVM） so that it can be solved by numerical methods for smooth constrained optimization. Our numerical experiments on artificial datasets show that LOSC-SVM （0 〈 p 〈 1） can improve the classification performance in both feature selection and classification by choosing a suitable parameter p. We also apply it to some real-life datasets and experimental results show that it is superior to L1-SVM.
基金This work was financially supported by the National Natural Science Foundation of China(No.51802205)Australian Research Council.
文摘Interface engineering has been regarded as an effective strategy to manipulate the thermoelectric performance of materials.Here,we use a facile chemical electroless plating and a spark plasma sintering process to fabricate Ag-plated SnTe bulk.After sintering,a small amount of plated Ag can be doped into SnTe to suppress the Sn vacancies and the others form Ag precipitates with a size distribution from nanoscale to microscale,which introduces Ag/SnTe interfaces to enhance the Seebeck coefficient via energy filtering effect.Simultaneously,these structures result in strong scattering to reach a low lattice thermal conductivity of-0.62 W·m^(–1)·K^(–1).Consequently,a maximum figure of merit(zT)of-0.67 at 823 K is achieved in 2 wt%Ag-plated SnTe,which is-60%higher than that of pristine SnTe.Moreover,the microhardness indentation test results show that the mean microhardness of 2 wt%Ag-plated SnTe is HV 64.26,which is much higher than that of pristine SnTe,indicating that Ag electroless plating can improve the mechanical properties of SnTe.This work has provided a facile and eco-friendly method to realize the interface engineering for manipulating the thermoelectric and mechanical properties of SnTe.
