Our gosl was to develop and experimentally validate a polarization-interferene method for phsae scanning of laser speckle fields generated by diffuse layers of birefringent biological tissues.This method isolates and ...Our gosl was to develop and experimentally validate a polarization-interferene method for phsae scanning of laser speckle fields generated by diffuse layers of birefringent biological tissues.This method isolates and uses new diagnostic parameters related to the"phsse WAvEs of local depolarization".We combined polarization-interferenæregistration with phase scanning of complex amplitude distributions in diffuse Laser speckle fields to detect phase waves of local depolarization in birefringent fibrillar networks of biological tisue and messure their modulation depth.This eppгоsch led to the discovery of new criteria for differentiating verious necrotic changes in diffuse histological samples of myocardial tisue from decmsed individuals with"ischemic heart disase(IHD)--cute coronary insufficiency(ACT)",even in the presænce of a high level of depolarized bckground.To evaluate the degree of necrotic changes in the optical anisotropy of difuse myocardial Layers,a new quantitative parameter--modulation depth of local depolarization wave fluctustions-has been proposed.Using this approsch,for the first time,differentiation of diffuse myocardial samples from decessed individuals with IHD and ACI was achieved witha very good 90.45%and outstanding aocuracy of 95.2%.展开更多
Asan emerging poserful tool to provide structural informstion af tissue specimens label-freely,Mueller matrix(MM)polarimetry has garnered extensive attention in biomedical studies and pathological diagnois.However,for...Asan emerging poserful tool to provide structural informstion af tissue specimens label-freely,Mueller matrix(MM)polarimetry has garnered extensive attention in biomedical studies and pathological diagnois.However,for the commonly used constant-step rotating MM polarimetricsystem,beam drift induæd by the rotation of polarization eements can lead to distortions in messurement results,severely affect ing MM imaging accuracy.Here,based on our previous study,we prоровe an optimizad self-registration method to mitigate the psæudo-depolarization effects introduced by image artifacts in constant-step rotatin g MM polarimetry.By addresing the prevalent issue of beam drift and image distortions in such polarimetric imaging systems,the effectivenes of the proposed method is experimentally validated using tissue samples.The result.s demonstrate a significant enhanæment in the accuIrsсy of depolarization parameter estimation after applying the optimized self-registration method.Furthermore,the method enhances the coarseness and contrsst of MM-derived parameters images,thereby bolstering their capacity to characterize tissuestructures.The optimized self-registration method proposed in this study can provide an innovstive spproach for quantitative tissue polarimetry bssæd on constant-step ro tating MM messurement,and contribute to the advanæment of polarimetric imaging technology in biomedical applications.展开更多
Lead-free Bi_(_(0.5))Na_(_(0.5))TiO_(3)(BNT)piezoelectric ceramics have the advantages of large coercive fields and high Curie temperatures.But the improvement of piezoelectric coefficient(d 33)is usually accompanied ...Lead-free Bi_(_(0.5))Na_(_(0.5))TiO_(3)(BNT)piezoelectric ceramics have the advantages of large coercive fields and high Curie temperatures.But the improvement of piezoelectric coefficient(d 33)is usually accompanied by a huge sacrifice of depolarization temperature(T d).In this work,a well-balanced performance of d 33 and T d is achieved in MnO_(2)-doped 0.79(Bi_(_(0.5))Na_(_(0.5))TiO_(3))-0.14(Bi_(0.5)K_(0.5)TiO_(3))-0.07BaTiO_(3)ternary ceramics.The in-corporation of 0.25 mol%MnO_(2)enhances the d 33 by more than 40%,while T d remains almost unchanged(i.e.,d 33=181 pC/N,T d=184℃).X-ray diffraction(XRD)shows that an appropriate fraction of the small axis-ratio ferroelectric phase(pseudo-cubic,P c)coexists with the long-range ferroelectric phase(tetrag-onal,T)under this MnO_(2)doping.Piezoelectric force microscopy(PFM)has revealed a special domain configuration,namely large striped and layered macro domains embedded with small nanodomains.This study provides a distinctive avenue to design BNT-based piezoelectric ceramics with high piezoelectric performance and temperature stability.展开更多
Enhanced piezoelectric response was usually achieved in(Bi_(0.5) Na_(0.5))TiO_(3)(BNT)-based ceramics with sacrifice of depolarization temperature T_(d),seriously limiting their usage range in electromechanical applic...Enhanced piezoelectric response was usually achieved in(Bi_(0.5) Na_(0.5))TiO_(3)(BNT)-based ceramics with sacrifice of depolarization temperature T_(d),seriously limiting their usage range in electromechanical applications.In this work,we propose to explore piezoelectric anisotropy and domain engineering in compositionµstructure-controlled textured ceramics to resolve this issue.[001]c-textured 0.94(Bi_(0.5) Na_(0.5))TiO_(3)–0.06BaTiO_(3)(0.94BNT-0.06BT)ceramics with Lotgering factor F_(001)-91% were fabricated through homoepitaxial templated grain growth(TGG)via using 0.94BNT-0.06BT microplatelet templates.The textured samples exhibited more ordered domains with facilitated domain switching behavior,being consistent with saturated high polarization achieved at lower electric fields.Increasing F_(001) to above 60%enables rapid enhancement of piezoelectric response.Notably,compared to non-textured counterpart,the maximally textured ceramics exhibited-236%enhanced piezoelectric coefficient(d_(33)-302 pC/N)and-280% enhanced piezoelectric voltage coefficient(g_(33)-49.8×10^(−3)Vm/N),together with slightly increased depolarization temperature(T_(d)-106℃).Moreover,those values are approaching or even higher than the single-crystal values.This work not only provides important guidelines for design and synthesis of novel textured ceramics with improved comprehensive electrical properties,but also can expand application fields of BNT-based ceramics.展开更多
Depolarizing behavior is commonly observed in most natural samples.For this reason,optical tools measuring the differences in depolarization response among spatially separated structures are highly useful in a wide ra...Depolarizing behavior is commonly observed in most natural samples.For this reason,optical tools measuring the differences in depolarization response among spatially separated structures are highly useful in a wide range of imaging applications for enhanced visualization of structures,target identification,etc.One commonly used tool for depolarizing discrimination is the so-called depolarizing spaces.In this article,we exploit the combined use of two depolarizing spaces,the indices of polarization purity(IPP)and polarizance–reflection–transformation(PRT)spaces,to improve the capability of optical systems to identify polarization–anisotropy depolarizers.The potential of these spaces to discriminate among different depolarizers is first studied from a series of simulations by incoherently adding diattenuations or retarders,with some control parameters emulating samples in nature.The simulated results demonstrate that the proposed methods are capable of increasing differences among depolarizers beyond other well-known techniques.Experimentally,validation is provided by conducting diverse phantom experiments of easy interpretation and mimicking the stated simulations.As a useful application of our approach,we developed a model able to retrieve intrinsic microscopic information of samples from macroscopic polarimetric measurements.The proposed methods enable non-invasive,straightforward,macroscopic characterization of depolarizing samples,and may be of interest for enhanced visualization of samples in multiple imaging scenarios.展开更多
Herein, the electrochemical behaviors of Sr on inert W electrode and reactive Zn/Al electrodes were systematically investig-ated in LiCl–KCl–SrCl2molten salts at 773 K using various electrochemical methods. The chem...Herein, the electrochemical behaviors of Sr on inert W electrode and reactive Zn/Al electrodes were systematically investig-ated in LiCl–KCl–SrCl2molten salts at 773 K using various electrochemical methods. The chemical reaction potentials of Li and Sr on re-active Zn/Al electrodes were determined. We observed that Sr could be extracted by decreasing the activity of the deposited metal Sr onthe reactive electrode, although the standard reduction potential of Sr(II)/Sr was more negative than that of Li(I)/Li. The electrochemicalextraction products of Sr on reactive Zn and Al electrodes were Zn13Sr and Al4Sr, respectively, with no codeposition of Li observed.Based on the density functional theory calculations, both Zn13Sr and Al4Sr were identified as stable intermetallic compounds with Zn-/Al-rich phases. In LiCl–KCl molten salt containing 3wt% SrCl2, the coulombic efficiency of Sr in the Zn electrode was ~54%. The depolar-ization values for Sr on Zn and Al electrodes were 0.864 and 0.485 V, respectively, exhibiting a stronger chemical interaction between Znand Sr than between Al and Sr. This study suggests that using reactive electrodes can facilitate extraction of Sr accumulated while elec-trorefining molten salts, thereby enabling the purification and reuse of the salt and decreasing the volume of the nuclear waste.展开更多
Maintaining the s-polarization state of laser beams is important to achieve high modulation depth in a laser-interference-based super-resolution structured illumination microscope(SR-SIM).However,the imperfect optical...Maintaining the s-polarization state of laser beams is important to achieve high modulation depth in a laser-interference-based super-resolution structured illumination microscope(SR-SIM).However,the imperfect optical components can depolarize the laser beams hence degenerating the modulation depth.Here,we first presented a direct measurement method designed to estimate the modulation depth more precisely by shifting illumination patterns with equal phase steps.This measurement method greatly reduces the dependence of modulation depths on the samples,and then developed a polarization optimization method to achieve high modulation depth at all orientations by actively and quantitatively compensating for the additional phase difference using a combination of waveplate and a liquid crystal variable retarder(LCVR).Experimental results demonstrate that our method can achieve illumination patterns with modulation depth higher than 0.94 at three orientations with only one LCVR voltage,which enables isotropic resolution improvement.展开更多
Ti-bearing slag(TiO2>20 wt%)is a valuable titanium secondary resource.The extraction of titanium from the slag is difficult due to the complex composition and structure.Although molten oxide electrolysis is conside...Ti-bearing slag(TiO2>20 wt%)is a valuable titanium secondary resource.The extraction of titanium from the slag is difficult due to the complex composition and structure.Although molten oxide electrolysis is considered as a promising method,silicon will be preferentially electroreduced compared to titanium due to low theoretical decomposition voltage.In this work,a liquid copper cathode is used to selectively extract titanium from molten Al2O3-MgO-CaO-TiO2-SiO2 electrolyte.It is found that comparing to silicon,titanium can be preferentially reduced by one-step electron transfer due to the enhanced depolarization effect on a liquid copper cathode.So,Ti-Cu alloys are firstly obtained from molten Ti-bearing slag,and then Ti-Si alloys are co-electrodeposited in the molten oxide electrolyte with low TiO2 content.It may be ascribed to the larger binding force between titanium and copper than that between silicon and copper.It provides an effective strategy for the separation of titanium from of Ti-bearing slag.展开更多
The Raman depolarization ratios of gaseous CO2 in the spectral range of 1240-1430 cm-I are determined with a sensitive photoacoustic Raman spectroscopy, and more accurate data compared to the literature results are pr...The Raman depolarization ratios of gaseous CO2 in the spectral range of 1240-1430 cm-I are determined with a sensitive photoacoustic Raman spectroscopy, and more accurate data compared to the literature results are presented. The precision of the obtained depolarization ratio is achieved by measuring and fitting the dependence of the PARS signal intensity on the cross angle between the polarizations of two incident laser beams.展开更多
Senescence impairs preosteoblast expansion and differentiation into functional osteoblasts,blunts their responses to bone formation-stimulating factors and stimulates their secretion of osteoclast-activating factors.D...Senescence impairs preosteoblast expansion and differentiation into functional osteoblasts,blunts their responses to bone formation-stimulating factors and stimulates their secretion of osteoclast-activating factors.Due to these adverse effects,preosteoblast senescence is a crucial target for the treatment of age-related bone loss;however,the underlying mechanism remains unclear.We found that mTORC1 accelerated preosteoblast senescence in vitro and in a mouse model.Mechanistically,mTORC1 induced a change in the membrane potential from polarization to depolarization,thus promoting cell senescence by increasing Ca^(2+)influx and activating downstream NFAT/ATF3/p53 signaling.We further identified the sodium channel Scn1a as a mediator of membrane depolarization in senescent preosteoblasts.Scn1a expression was found to be positively regulated by mTORC1 upstream of C/EBPα,whereas its permeability to Na^(+)was found to be gated by protein kinase A(PKA)-induced phosphorylation.Prosenescent stresses increased the permeability of Scn1a to Na^(+)by suppressing PKA activity and induced depolarization in preosteoblasts.Together,our findings identify a novel pathway involving mTORC1,Scn1a expression and gating,plasma membrane depolarization,increased Ca^(2+)influx and NFAT/ATF3/p53 signaling in the regulation of preosteoblast senescence.Pharmaceutical studies of the related pathways and agents might lead to novel potential treatments for agerelated bone loss.展开更多
An improved transverse Ising model is proposed by taking the depolarization field effect into account. Within the framework of mean-held theory we investigate the behavior of the ferroelectric thin film. Our results s...An improved transverse Ising model is proposed by taking the depolarization field effect into account. Within the framework of mean-held theory we investigate the behavior of the ferroelectric thin film. Our results show that the influence of the depolarization field is to flatten the spontaneous polarization profile and make the films more homogeneous, which is consistent with Ginzburg Landau theory. This fact shows that this model can be taken as an effective model to deal with the ferroelectric film and can be further extended to refer to quantum effect. The competition between quantum effect and depolarization field induces some interesting phenomena on ferroelectric thin films.展开更多
The performance and capacity of multiple-input multiple-output (MIMO) wireless channels are limited by the spatial fading correlation between antenna elements. This limitation is due to the use of mono polarized anten...The performance and capacity of multiple-input multiple-output (MIMO) wireless channels are limited by the spatial fading correlation between antenna elements. This limitation is due to the use of mono polarized antennas at receiver and transmitter sides. In this paper, in order to reduce the antenna correlation, the polarization diversity technique is employed. Although the spatial antenna correlation is attenuated for multi-polarization configurations, the cross-polar components appear. This paper highlights the impact of depolarization effect on the MIMO channel capacity for a 4×4 uniform linear antenna array. We assume that the channel is unknown at the transmitter and perfectly known at the receiver so that equal power is distributed to each of the transmit antennas. The numerical results illustrate that for low depolarization and spatial correlation, the capacity of single-polarization configuration behaves better than that of multi-polarization configuration.展开更多
文摘Our gosl was to develop and experimentally validate a polarization-interferene method for phsae scanning of laser speckle fields generated by diffuse layers of birefringent biological tissues.This method isolates and uses new diagnostic parameters related to the"phsse WAvEs of local depolarization".We combined polarization-interferenæregistration with phase scanning of complex amplitude distributions in diffuse Laser speckle fields to detect phase waves of local depolarization in birefringent fibrillar networks of biological tisue and messure their modulation depth.This eppгоsch led to the discovery of new criteria for differentiating verious necrotic changes in diffuse histological samples of myocardial tisue from decmsed individuals with"ischemic heart disase(IHD)--cute coronary insufficiency(ACT)",even in the presænce of a high level of depolarized bckground.To evaluate the degree of necrotic changes in the optical anisotropy of difuse myocardial Layers,a new quantitative parameter--modulation depth of local depolarization wave fluctustions-has been proposed.Using this approsch,for the first time,differentiation of diffuse myocardial samples from decessed individuals with IHD and ACI was achieved witha very good 90.45%and outstanding aocuracy of 95.2%.
基金funded by the National Natural Science Foundation of China(NSFC)under Grant No.62335007.
文摘Asan emerging poserful tool to provide structural informstion af tissue specimens label-freely,Mueller matrix(MM)polarimetry has garnered extensive attention in biomedical studies and pathological diagnois.However,for the commonly used constant-step rotating MM polarimetricsystem,beam drift induæd by the rotation of polarization eements can lead to distortions in messurement results,severely affect ing MM imaging accuracy.Here,based on our previous study,we prоровe an optimizad self-registration method to mitigate the psæudo-depolarization effects introduced by image artifacts in constant-step rotatin g MM polarimetry.By addresing the prevalent issue of beam drift and image distortions in such polarimetric imaging systems,the effectivenes of the proposed method is experimentally validated using tissue samples.The result.s demonstrate a significant enhanæment in the accuIrsсy of depolarization parameter estimation after applying the optimized self-registration method.Furthermore,the method enhances the coarseness and contrsst of MM-derived parameters images,thereby bolstering their capacity to characterize tissuestructures.The optimized self-registration method proposed in this study can provide an innovstive spproach for quantitative tissue polarimetry bssæd on constant-step ro tating MM messurement,and contribute to the advanæment of polarimetric imaging technology in biomedical applications.
基金supported by the Natural Science Foundation of Heilongjiang Province(No.LH2021A012).
文摘Lead-free Bi_(_(0.5))Na_(_(0.5))TiO_(3)(BNT)piezoelectric ceramics have the advantages of large coercive fields and high Curie temperatures.But the improvement of piezoelectric coefficient(d 33)is usually accompanied by a huge sacrifice of depolarization temperature(T d).In this work,a well-balanced performance of d 33 and T d is achieved in MnO_(2)-doped 0.79(Bi_(_(0.5))Na_(_(0.5))TiO_(3))-0.14(Bi_(0.5)K_(0.5)TiO_(3))-0.07BaTiO_(3)ternary ceramics.The in-corporation of 0.25 mol%MnO_(2)enhances the d 33 by more than 40%,while T d remains almost unchanged(i.e.,d 33=181 pC/N,T d=184℃).X-ray diffraction(XRD)shows that an appropriate fraction of the small axis-ratio ferroelectric phase(pseudo-cubic,P c)coexists with the long-range ferroelectric phase(tetrag-onal,T)under this MnO_(2)doping.Piezoelectric force microscopy(PFM)has revealed a special domain configuration,namely large striped and layered macro domains embedded with small nanodomains.This study provides a distinctive avenue to design BNT-based piezoelectric ceramics with high piezoelectric performance and temperature stability.
基金financial support from the National Natural Science Foundation of China(Nos.52072092 and 51922083)the Natural Science Foundation of Heilongjiang Province(No.YQ2019E026)the Fundamental Research Funds for the Central Universities(No.HIT.OCEF.2021018).
文摘Enhanced piezoelectric response was usually achieved in(Bi_(0.5) Na_(0.5))TiO_(3)(BNT)-based ceramics with sacrifice of depolarization temperature T_(d),seriously limiting their usage range in electromechanical applications.In this work,we propose to explore piezoelectric anisotropy and domain engineering in compositionµstructure-controlled textured ceramics to resolve this issue.[001]c-textured 0.94(Bi_(0.5) Na_(0.5))TiO_(3)–0.06BaTiO_(3)(0.94BNT-0.06BT)ceramics with Lotgering factor F_(001)-91% were fabricated through homoepitaxial templated grain growth(TGG)via using 0.94BNT-0.06BT microplatelet templates.The textured samples exhibited more ordered domains with facilitated domain switching behavior,being consistent with saturated high polarization achieved at lower electric fields.Increasing F_(001) to above 60%enables rapid enhancement of piezoelectric response.Notably,compared to non-textured counterpart,the maximally textured ceramics exhibited-236%enhanced piezoelectric coefficient(d_(33)-302 pC/N)and-280% enhanced piezoelectric voltage coefficient(g_(33)-49.8×10^(−3)Vm/N),together with slightly increased depolarization temperature(T_(d)-106℃).Moreover,those values are approaching or even higher than the single-crystal values.This work not only provides important guidelines for design and synthesis of novel textured ceramics with improved comprehensive electrical properties,but also can expand application fields of BNT-based ceramics.
基金supported by the China Scholarship Council(Grant No.202306690024)the Ministerio de Ciencia e Innovación and Fondos FEDER(Grant Nos.PID2021-562126509OB-C21 and PDC2022-133332-C21)+1 种基金the Generalitat de Catalunya(Grant No.2021SGR00138)the Beatriu de Pinós Fellowship(Grant No.2021-BP-00206).
文摘Depolarizing behavior is commonly observed in most natural samples.For this reason,optical tools measuring the differences in depolarization response among spatially separated structures are highly useful in a wide range of imaging applications for enhanced visualization of structures,target identification,etc.One commonly used tool for depolarizing discrimination is the so-called depolarizing spaces.In this article,we exploit the combined use of two depolarizing spaces,the indices of polarization purity(IPP)and polarizance–reflection–transformation(PRT)spaces,to improve the capability of optical systems to identify polarization–anisotropy depolarizers.The potential of these spaces to discriminate among different depolarizers is first studied from a series of simulations by incoherently adding diattenuations or retarders,with some control parameters emulating samples in nature.The simulated results demonstrate that the proposed methods are capable of increasing differences among depolarizers beyond other well-known techniques.Experimentally,validation is provided by conducting diverse phantom experiments of easy interpretation and mimicking the stated simulations.As a useful application of our approach,we developed a model able to retrieve intrinsic microscopic information of samples from macroscopic polarimetric measurements.The proposed methods enable non-invasive,straightforward,macroscopic characterization of depolarizing samples,and may be of interest for enhanced visualization of samples in multiple imaging scenarios.
基金financially supported by the National Postdoctoral Program for Innovative Talents, China (No. BX2021327)the National Natural Science Foundation of China (Nos. 22206194 and U2267222)+1 种基金the Ningbo Natural Science Foundation of China (No. 2023J337)the Yongjiang Talent Introduction Programme, China (No. 2 021A-161-G)。
文摘Herein, the electrochemical behaviors of Sr on inert W electrode and reactive Zn/Al electrodes were systematically investig-ated in LiCl–KCl–SrCl2molten salts at 773 K using various electrochemical methods. The chemical reaction potentials of Li and Sr on re-active Zn/Al electrodes were determined. We observed that Sr could be extracted by decreasing the activity of the deposited metal Sr onthe reactive electrode, although the standard reduction potential of Sr(II)/Sr was more negative than that of Li(I)/Li. The electrochemicalextraction products of Sr on reactive Zn and Al electrodes were Zn13Sr and Al4Sr, respectively, with no codeposition of Li observed.Based on the density functional theory calculations, both Zn13Sr and Al4Sr were identified as stable intermetallic compounds with Zn-/Al-rich phases. In LiCl–KCl molten salt containing 3wt% SrCl2, the coulombic efficiency of Sr in the Zn electrode was ~54%. The depolar-ization values for Sr on Zn and Al electrodes were 0.864 and 0.485 V, respectively, exhibiting a stronger chemical interaction between Znand Sr than between Al and Sr. This study suggests that using reactive electrodes can facilitate extraction of Sr accumulated while elec-trorefining molten salts, thereby enabling the purification and reuse of the salt and decreasing the volume of the nuclear waste.
基金supported by the National Natural Science Foundation of China[Grant Nos.62205367 and 62141506]the Suzhou Basic Research Pilot Project[Grant Nos.SSD2023006 and SJC2021013]the National Key Research and Development Program of China[Grant No.2023YFF1205700].
文摘Maintaining the s-polarization state of laser beams is important to achieve high modulation depth in a laser-interference-based super-resolution structured illumination microscope(SR-SIM).However,the imperfect optical components can depolarize the laser beams hence degenerating the modulation depth.Here,we first presented a direct measurement method designed to estimate the modulation depth more precisely by shifting illumination patterns with equal phase steps.This measurement method greatly reduces the dependence of modulation depths on the samples,and then developed a polarization optimization method to achieve high modulation depth at all orientations by actively and quantitatively compensating for the additional phase difference using a combination of waveplate and a liquid crystal variable retarder(LCVR).Experimental results demonstrate that our method can achieve illumination patterns with modulation depth higher than 0.94 at three orientations with only one LCVR voltage,which enables isotropic resolution improvement.
基金supported by the National Natural Science Foundation of China(51725401)the Fundamental Research Funds for the Central Universities(FRF-TP-18-010B1).
文摘Ti-bearing slag(TiO2>20 wt%)is a valuable titanium secondary resource.The extraction of titanium from the slag is difficult due to the complex composition and structure.Although molten oxide electrolysis is considered as a promising method,silicon will be preferentially electroreduced compared to titanium due to low theoretical decomposition voltage.In this work,a liquid copper cathode is used to selectively extract titanium from molten Al2O3-MgO-CaO-TiO2-SiO2 electrolyte.It is found that comparing to silicon,titanium can be preferentially reduced by one-step electron transfer due to the enhanced depolarization effect on a liquid copper cathode.So,Ti-Cu alloys are firstly obtained from molten Ti-bearing slag,and then Ti-Si alloys are co-electrodeposited in the molten oxide electrolyte with low TiO2 content.It may be ascribed to the larger binding force between titanium and copper than that between silicon and copper.It provides an effective strategy for the separation of titanium from of Ti-bearing slag.
基金This work was supported by the National Natural Sci- ence Foundation of China （No.20903002, No.21273211, No.9112T042, and No.21373194） and the Anhui Provin- cial Natural Science Foundation （No.1408085MA18）, and the National Key Basic Research Special Founda- tion （No.2013CB834602 and No.2010CB923300）.
文摘The Raman depolarization ratios of gaseous CO2 in the spectral range of 1240-1430 cm-I are determined with a sensitive photoacoustic Raman spectroscopy, and more accurate data compared to the literature results are presented. The precision of the obtained depolarization ratio is achieved by measuring and fitting the dependence of the PARS signal intensity on the cross angle between the polarizations of two incident laser beams.
基金supported by grants 82172507 (B.H.), 81700783 (B.H.)and 81672120 (D.J.) from the National Natural Science Foundation of China+1 种基金2019A1515011876 (B.H.) and 2018A030313937 (Z.L.) from the Guangdong Natural Science Fund Management Committee202002030176 (B.H.) from the Guangzhou Municipal Science and Technology Bureau
文摘Senescence impairs preosteoblast expansion and differentiation into functional osteoblasts,blunts their responses to bone formation-stimulating factors and stimulates their secretion of osteoclast-activating factors.Due to these adverse effects,preosteoblast senescence is a crucial target for the treatment of age-related bone loss;however,the underlying mechanism remains unclear.We found that mTORC1 accelerated preosteoblast senescence in vitro and in a mouse model.Mechanistically,mTORC1 induced a change in the membrane potential from polarization to depolarization,thus promoting cell senescence by increasing Ca^(2+)influx and activating downstream NFAT/ATF3/p53 signaling.We further identified the sodium channel Scn1a as a mediator of membrane depolarization in senescent preosteoblasts.Scn1a expression was found to be positively regulated by mTORC1 upstream of C/EBPα,whereas its permeability to Na^(+)was found to be gated by protein kinase A(PKA)-induced phosphorylation.Prosenescent stresses increased the permeability of Scn1a to Na^(+)by suppressing PKA activity and induced depolarization in preosteoblasts.Together,our findings identify a novel pathway involving mTORC1,Scn1a expression and gating,plasma membrane depolarization,increased Ca^(2+)influx and NFAT/ATF3/p53 signaling in the regulation of preosteoblast senescence.Pharmaceutical studies of the related pathways and agents might lead to novel potential treatments for agerelated bone loss.
文摘An improved transverse Ising model is proposed by taking the depolarization field effect into account. Within the framework of mean-held theory we investigate the behavior of the ferroelectric thin film. Our results show that the influence of the depolarization field is to flatten the spontaneous polarization profile and make the films more homogeneous, which is consistent with Ginzburg Landau theory. This fact shows that this model can be taken as an effective model to deal with the ferroelectric film and can be further extended to refer to quantum effect. The competition between quantum effect and depolarization field induces some interesting phenomena on ferroelectric thin films.
文摘The performance and capacity of multiple-input multiple-output (MIMO) wireless channels are limited by the spatial fading correlation between antenna elements. This limitation is due to the use of mono polarized antennas at receiver and transmitter sides. In this paper, in order to reduce the antenna correlation, the polarization diversity technique is employed. Although the spatial antenna correlation is attenuated for multi-polarization configurations, the cross-polar components appear. This paper highlights the impact of depolarization effect on the MIMO channel capacity for a 4×4 uniform linear antenna array. We assume that the channel is unknown at the transmitter and perfectly known at the receiver so that equal power is distributed to each of the transmit antennas. The numerical results illustrate that for low depolarization and spatial correlation, the capacity of single-polarization configuration behaves better than that of multi-polarization configuration.
