A highly sensitive light-induced thermoelectric spectroscopy(LITES)sensor based on a multi-pass cell(MPC)with dense spot pattern and a novel quartz tuning fork(QTF)with low resonance frequency is reported in this manu...A highly sensitive light-induced thermoelectric spectroscopy(LITES)sensor based on a multi-pass cell(MPC)with dense spot pattern and a novel quartz tuning fork(QTF)with low resonance frequency is reported in this manuscript.An erbi-um-doped fiber amplifier(EDFA)was employed to amplify the output optical power so that the signal level was further enhanced.The optical path length(OPL)and the ratio of optical path length to volume(RLV)of the MPC is 37.7 m and 13.8 cm^(-2),respectively.A commercial QTF and a self-designed trapezoidal-tip QTF with low frequency of 9461.83 Hz were used as the detectors of the sensor,respectively.The target gas selected to test the performance of the system was acetylene(C2H2).When the optical power was constant at 1000 mW,the minimum detection limit(MDL)of the C2H2-LITES sensor can be achieved 48.3 ppb when using the commercial QTF and 24.6 ppb when using the trapezoid-al-tip QTF.An improvement of the detection performance by a factor of 1.96 was achieved after replacing the commer-cial QTF with the trapezoidal-tip QTF.展开更多
It is necessary to investigate the characteristics of Mesenchymal stem cells(MSCs)derived exosomes,and especially their application in tissue regeneration.Previous studies have shown that inflammatory stimulation enha...It is necessary to investigate the characteristics of Mesenchymal stem cells(MSCs)derived exosomes,and especially their application in tissue regeneration.Previous studies have shown that inflammatory stimulation enhanced the secretion of MSC-derived exosomes with stronger anti-inflammatory protein,cytokine profiles,and functional RNA via altering COX2/PGE2 pathway.Recently,accumulating evidence has also revealed that biophysical cues(especially biomechanical cues)in cell microenvironment have significant effects not only on cells but also on their exosomes.It has been reported that applying bi-axial strain to MSCs induces formation of a stiffer cytoskeleton through mTORC2 signaling,which biases against adipogenic differentiation and toward osteoblastogenesis.At the same time,For example,dimensionality,composition and stiffness of the extracellular matrix(ECM)has been proved to affect the size and composition of exosomes secreted by cancer cells.However,the effects of biomechanical cues in the three-dimensional(3D)microenvironment on stem cell-derived exosomes remains to be unveiled.Therefore,it is important to understand the roles of 3D cell mechanical microenvironment in regulating the characteristics of stem cell-derived exosomes and develop more efficient approaches to enhance their functions.This study aimed to explore the changes in characteristics of exosomes secreted by MSCs in periodontium in response to the matrix strain in 3D.Periodontal ligament stem cells(PDLSCs)were cultured in a 3D strain microenvironment engineered with microscale magnetically stretched collagen hydrogels.The morphology,particle distribution,marker protein expression of PDLSC-derived exosomes were analyzed.Then the pro-osteogenic property of exosomes was evaluated by assessing cell viability,proliferation,migration and osteogenic differentiation of target cells,for instance human bone marrow mesenchymal stem cells(hBMSCs).Detailed characterizations revealed that PDLSC-derived exosomes in the 3D strain mi-croenvironment were with similar morphology,particle distribution and surface markers.Notably,Exosomes secreted by PDLSCs in strain microenvironment were more endocytosed by hBMSCs and were more potent in improving proliferation and migration of hBMSCs,comparing with PDLSCs in non-strain environment.Alizarin red staining and molecular biology experiments confirmed that treatment of exosomes secreted by PDLSCs under mechanical stimulation led to a significant increase in osteogenic differentiation of hBMSCs in vitro.Meanwhile,in vivo study also indicated that PDLSC-derived exosomes obtained from the 3D strain microenvironment could obviously promote new bone formation.Our findings revealed that mechanical cues profoundly affected the characteristics of PDLSC-derived exosomes,especially for their bio-activity,providing a foundation for using the 3D mechanical microenvironment to enhance the osteo-inductive functions of stem cell-derived exosomes in cell-free therapy for bone regeneration.展开更多
The limited bioactivity of scaffold materials is an important factor that restricts the development of bone tissue engineering.Wnt3a activates the classicWnt/β-catenin signaling pathway which effects bone growth and ...The limited bioactivity of scaffold materials is an important factor that restricts the development of bone tissue engineering.Wnt3a activates the classicWnt/β-catenin signaling pathway which effects bone growth and development by the accumulation ofβ-catenin in the nucleus.In this study,we fabricated 3D printed PCL scaffold with Wnt3a-induced murine bone marrow-derived stromal cell line ST2 decellularized matrix(Wnt3a-ST2-dCM-PCL)and ST2 decellularized matrix(ST2-dCM-PCL)by freeze-thaw cycle and DNase decellularization treatment which efficiently decellularized>90%DNA while preserved most protein.Compared to ST2-dCM-PCL,Wnt3a-ST2-dCM-PCL significantly enhanced newly-seeded ST2 proliferation,osteogenic differentiation and upregulated osteogenic marker genes alkaline phosphatase(Alp),Runx2,type I collagen(Col 1)and osteocalcin(Ocn)mRNA expression.After 14 days of osteogenic induction,Wnt3a-ST2-dCM-PCL promoted ST2 mineralization.These results demonstrated that Wnt3a-induced ST2 decellularized matrix improve scaffold materials’osteoinductivity and osteoconductivity.展开更多
Cell source is the key to decellularized matrix(DM)strategy.This study compared 3 cell types,osteocytes with/without dominant active Wnt/β-catenin signaling(daCO and WTO)and bone marrow stromal cells(BMSCs)for their ...Cell source is the key to decellularized matrix(DM)strategy.This study compared 3 cell types,osteocytes with/without dominant active Wnt/β-catenin signaling(daCO and WTO)and bone marrow stromal cells(BMSCs)for their DMs in bone repair.Decellularization removes all organelles and>95%DNA,and retained>74%collagen and>71%GAG,maintains the integrity of cell basement membrane with dense boundaries showing oval and honeycomb structure in osteocytic DM and smooth but irregular shape in the BMSC-DM.DM produced higher cell survival rate(90%)and higher proliferative activity.In vitro,daCO-DM induces more and longer stress fibers in BMSCs,conducive to cell adhesion,spreading,and osteogenic differentiation.8-wk after implantation of the critical-sized parietal bone defect model,daCO-DM formed tight structures,composed of a large number of densely-arranged type-I collagen under polarized light microscope,which is similar to and integrated with host bone.BV/TV(>54%)was 1.5,2.9,and 3.5 times of WTO-DM,BMSC-DM,and none-DM groups,and N.Ob/T.Ar(3.2×10^(2)/mm^(2))was 1.7,2.9,and 3.3 times.At 4-wk,daCO-DM induced osteoclastogenesis,2.3 times higher than WTO-DM;but BMSC-DM or none-DM didn't.daCO-DM increased the expression of RANKL and MCSF,Vegfa and Angpt1,and Ngf in BMSCs,which contributes to osteoclastogenesis,angiogenesis,and neurogenesis,respectively.daCO-DM promoted H-type vessel formation and nerve markersβ3-tubulin and NeuN expression.Conclusion:daCO-DM produces metabolic and neurovascularized organoid bone to accelerate the repair of bone defects.These features are expected to achieve the effect of autologous bone transplantation,suitable for transformation application.展开更多
Integrin αvβ3,a cell adhesion molecule,plays a key role in angiogenesis and tumor cell metastasis and is therefore an important target for new therapeutic and diagnostic strategies.Since RGD bind to αvβ3 particula...Integrin αvβ3,a cell adhesion molecule,plays a key role in angiogenesis and tumor cell metastasis and is therefore an important target for new therapeutic and diagnostic strategies.Since RGD bind to αvβ3 particularly,a lot of RGD containing peptides were radiolabeled and evaluated as imaging or therapeutic agents.In this study,a new 188Re-RGD peptide analog was synthesized and characterized.Within 30min,the 188Re-H-E[c(RGDyK)]2 was obtained in radiochemical purity of better than 95%.The His-E[c(RGDyK)]2 had a good integrin-binding affinity (50% inhibitiory concentracer (IC50=46.5×10-9 nm) and exhibited active accumulation (7.20±1.06) in S180 tumor.Because of relatively fast washout in blood and normal tissues,the target/non-target ratio was high.Further experiments to improve the tumor targeting efficacy and in vivo kinetic profiles are in progress towards developing it into a promising radio agent.展开更多
A highly sensitive carbon dioxide(CO_(2))sensor based on light-induced thermoelastic spectroscopy(LITES)utilizing a selfdesigned low-frequency quartz tuning fork(QTF)and a fiber-coupled multipass cell(MPC)is reported ...A highly sensitive carbon dioxide(CO_(2))sensor based on light-induced thermoelastic spectroscopy(LITES)utilizing a selfdesigned low-frequency quartz tuning fork(QTF)and a fiber-coupled multipass cell(MPC)is reported in this paper.The QTF with a low resonant frequency of 8675 Hz and a high Q factor of 11,675.64 was used to improve its energy accumulation time and the sensor’s signal level.The MPC with the fiber-coupled structure and optical length of 40 m was adopted to significantly increase the gas absorbance and reduce the optical alignment difficulty as well as improve the robustness of the sensor system.A distributed feedback(DFB),near-infrared diode laser with an emission wavelength of 1.57μm was used as an excitation source.The experimental results showed that this CO_(2)-LITES sensor had an excellent linear response to CO_(2) concentrations.The minimum detection limitation(MDL)of this CO_(2)-LITES sensor was obtained to be 445.91 ppm,and it could be improved to 47.70 ppm(parts per million)when the integration time of the system reached 500 s.Further improvement methods for the detection performance of such sensors were also discussed.展开更多
Photoacoustic spectroscopy(PAS)as a highly sensitive and selective trace gas detection technique has extremely broad application in many fields.However,the laser sources currently used in PAS limit the sensing perform...Photoacoustic spectroscopy(PAS)as a highly sensitive and selective trace gas detection technique has extremely broad application in many fields.However,the laser sources currently used in PAS limit the sensing performance.Compared to diode laser and quantum cascade laser,the solid-state laser has the merits of high optical power,excellent beam quality,and wide tuning range.Here we present a long-wave,high-power,wide-tunable,singlelongitudinal-mode solid-state laser used as light source in a PAS sensor for trace gas detection.The self-built solid-state laser had an emission wavelength of~2μm with Tm:YAP crystal as the gain material,with an excellent wavelength and optical power stability as well as a high beam quality.The wide wavelength tuning range of 9.44 nm covers the absorption spectra of water and ammonia,with a maximum optical power of~130 mW,allowing dual gas detection with a single laser source.The solid-state laser was used as light source in three different photoacoustic detection techniques:standard PAS with microphone,and external-and intra-cavity quartz-enhanced photoacoustic spectroscopy(QEPAS),proving that solid-state laser is an attractive excitation source in photoacoustic spectroscopy.展开更多
Element doping and nano-inclusion embedding are effective approaches to enhance the electrical conductivities and decrease the lattice thermal conductivities of thermoelectric(TE)materials,respectively.However,the int...Element doping and nano-inclusion embedding are effective approaches to enhance the electrical conductivities and decrease the lattice thermal conductivities of thermoelectric(TE)materials,respectively.However,the intrinsic low electrical thermal conductivities and high electrical properties are severely sacrificed,and the final figure of merit(ZT)is usually restricted.In this study,Ag doping and Pt quantum dot(QD)embedding were synchronously achieved via embedding Ag/Pt alloy QDs into the higher manganese silicides to avoid the conventional single-element doping strategy.The power factor(at 823 K)was enhanced from 1.57×10^(-3) W m^(-1) K^(-2) to 1.82×10^(-3) W m^(-1) K^(-2)(-16%)due to the-18%increase in carrier concentration that was derived from the Ag doping effect.Simultaneously,the lattice thermal conductivity(at 823 K)decreased from 2.65 W m^(-1) K^(-1) e1.92 W m^(-1) K^(-1)(-28%)because of the broadband phonon scattering effect that resulted from the residual Pt QDs inclusions.Synthetically,the optimal ZT value increased by-52%from 0.42 to 0.64 at 823 K.This study demonstrated that incorporating metastable alloy QDs to obtain element doping and nano-inclusion embedding effects is a novel and feasible means to enhance the ZT value of HMS.This method is also possibly applicable to other alloy QD/TE composites.展开更多
Direct electrolytic splitting of seawater for the production of H2 using ocean energy is a promising technology that can help achieve carbon neutrality.However,owing to the high concentrations of chlorine ions in seaw...Direct electrolytic splitting of seawater for the production of H2 using ocean energy is a promising technology that can help achieve carbon neutrality.However,owing to the high concentrations of chlorine ions in seawater,the chlorine evolution reaction always competes with the oxygen evolution reaction(OER)at the anode,and chloride corrosion occurs on both the anode and cathode.Thus,effective electrocatalysts with high selectivity toward the OER and excellent resistance to chloride corrosion should be developed.In this critical review,we focus on the prospects of state-of-the-art metal-oxide electrocatalysts,including noble metal oxides,non-noble metal oxides and their compounds,and spinel-and perovskite-type oxides,for seawater splitting.We elucidate their chemical properties,excellent OER selectivity,outstanding anti-chlorine-corrosion performance,and reaction mechanisms.In particular,we review metal oxides that operate at high current densities,near industrial application levels,based on special catalyst design strategies.展开更多
As a new energy source,hydrogen(H_(2))detection is a hot topic in recent years.Because of the weak absorption characteristic,laser spectroscopy-based H_(2)detection is challenging.In this paper,a highly sensitive H_(2...As a new energy source,hydrogen(H_(2))detection is a hot topic in recent years.Because of the weak absorption characteristic,laser spectroscopy-based H_(2)detection is challenging.In this paper,a highly sensitive H_(2)sensor based on light-induced thermoelastic spectroscopy(LITES)technique is demonstrated for the first time.A continuous-wave,distributed feedback diode laser with emission in the 2.1μm region was adopted as the excitation source to target the strongest H_(2)absorption line of 4,712.90 cm^(−1).A Herriott multipass cell with an optical length of 10.1 m was chosen to further improve the H_(2)absorption.With the feature of processing the raw input data without data preprocessing and extracting the desired features automatically,the robust shallow neural network(SNN)fitting algorithm was brought in to denoise the sensor.For the LITES-based H_(2)sensor,the concentration response was tested,and an excellent linear response to H_(2)concentration levels was achieved.A minimum detection limit(MDL)of~80 ppm was obtained.On the basis of implementation of the H_(2)-LITES sensor,a heterodyne H_(2)-LITES sensor was further constructed to realize a fast measurement of resonance frequency of quartz tuning fork and H_(2)concentration simultaneously.The resonance frequency can be retrieved in several hundred milliseconds with the measurement accuracy of±0.2 Hz,and the result of 30,713.76 Hz is exactly same as the experimentally determined value of 30,713.69 Hz.After the SNN algorithm was applied,an MDL of~45 ppm was achieved for this heterodyne H_(2)-LITES sensor.展开更多
Fabry-Perot(F-P)-based phase demodulation of heterodyne light-induced thermoelastic spectroscopy(H-LITES)was demonstrated for the first time in this study.The vibration of a quartz tuning fork(QTF)was detected using t...Fabry-Perot(F-P)-based phase demodulation of heterodyne light-induced thermoelastic spectroscopy(H-LITES)was demonstrated for the first time in this study.The vibration of a quartz tuning fork(QTF)was detected using the F-P interference principle instead of an electrical signal through the piezoelectric effect of the QTF in traditional LITES to avoid thermal noise.Given that an Fabry-Perot interferometer(FPI)is vulnerable to disturbances,a phase demodulation method that has been demonstrated theoretically and experimentally to be an effective solution for instability was used in H-LITES.The sensitivity of the F-P phase demodulation method based on the H-LITES sensor was not associated with the wavelength or power of the probe laser.Thus,stabilising the quadrature working point(Q-point)was no longer necessary.This new method of phase demodulation is structurally simple and was found to be resistant to interference from light sources and the surroundings using the LITES technique.展开更多
sensor based on light-induced thermoelastic spectroscopy(LITES)with a fiber-coupled multipass cell was demonstrated for carbon monoxide(CO)detection.The fiber-coupled structure has the merits of reducing optical inter...sensor based on light-induced thermoelastic spectroscopy(LITES)with a fiber-coupled multipass cell was demonstrated for carbon monoxide(CO)detection.The fiber-coupled structure has the merits of reducing optical interference and difficulty in optical alignment and increasing system robustness.A 1.57 nm continuous wave distributed feedback diode laser was used as the excitation source.A minimum detection limit of 9 ppm was obtained,and the calculated normalized noise equivalent absorption coefficient was 1.15×10^(-7)cm^(-1)•W•Hz^(-1/2).The reported CO-LITES sensor showed excellent linear concentration response and system stability.展开更多
Purpose In order to update the BPM electronic in BEPCII,a high-performance digital BPM processor is designed,and the RF front-end electronic is the key part in the digital BPM processor system.Methods According to the...Purpose In order to update the BPM electronic in BEPCII,a high-performance digital BPM processor is designed,and the RF front-end electronic is the key part in the digital BPM processor system.Methods According to the BEPCII physical parameters andADCunder-sampling theorem,the low-noise and high-dynamicrange RF front-end electronic module is designed.This article will introduce filter,RF amplifier,isolation,system test,etc.Results and conclusions The experimental results showed that BPM position short-term resolution is better than 100 nm,and long-term resolution is better than 5μm.It is the first domestic BPM processor that runs stably in the storage ring accelerator for a long time.Meanwhile,the study can help us to establish a solid foundation for the next work of BPM electronics development.展开更多
Background:Changes in thyroid hormone levels are commonly recognized characters among the elderly,which were reported to potentially influence incident frailty.Therefore,we examined the cross-sectional associations of...Background:Changes in thyroid hormone levels are commonly recognized characters among the elderly,which were reported to potentially influence incident frailty.Therefore,we examined the cross-sectional associations of thyroid hormones(THs)with frailty as well as the five components characterizing frailty(fatigue,resistance,ambulation,number ofillnesses,and loss of weight)among the oldest-old.Methods:Four hundred and eighty-seven community-dwelling oldest-old from a local community in Haidian District,Beijing,participated in our recruitment campaign between April 2019 and May 2020.The primary outcomes were a definitive diagnosis of frailty according to the FRAIL scale(Fatigue,Resistance,Ambulation,Illnesses,Loss of weight)and a positive score for each frailty subdomain.Demographic information(age,sex,marital status,and educational status),comorbidities,and details on the participants lifestyles were recorded.Serum THs including free triodothyronin(fT3),triiodothyronine(T3),free thyroxine(fT4),and thyroxine(T4)and thyroid stimulating hormone(TSH)levels were also measured at the beginning of our study.Logistic regressions were conducted to screen for potential risk factors for frailty and its subdomains.Results:Among the total 487 subjects at enrollment,60(12.23%)of them were diagnosed with subclinical hypothyroidism and 110(22.59%)of the total population scored positive for frailty.Logistic regression analyses adjusted for all potential confounders,showed that frailty was significantly associated with the serum TSH concentration(odds ratio[OR]:1.06),fT3 concentration(OR:0.54),and subclinical hypothyroidism score(OR:2.18).The association between fT4 and frailty was absent in our observational study.The fT3/fT4 ratio characterizing peripheral hormone conversion was also tested to be correlated with frailty.Conclusion:Subclinical hypothyroidism,higher TSH level,lower fT3 level,and decreased fT3/fT4 ratio were all associated with frailty assessed by the FRAIL scale among the community-dwelling oldest-old,suggesting a relevant role of thyroid function in aging.Future longitudinal studies are warranted to determine the casual relationship between thyroid dysfunction and frailty in the oldest-old.展开更多
Graphene oxide(GO)has demonstrated potential applications in various fields,and attracted intensive attention in industry as well.Numerous companies worldwide have been working on the industrial applications of GO-bas...Graphene oxide(GO)has demonstrated potential applications in various fields,and attracted intensive attention in industry as well.Numerous companies worldwide have been working on the industrial applications of GO-based materials in,e.g.,thermal management,multifunctional composites,anti-corrosion paints,lubricants,energy storage,environment protection and biomedicals.This review presents a short summary on the proceedings of GO towards industrialization,including the large-scale production and some promising applications,by providing views on the processing strategies and challenges specifically for the industrial use of GO.This review would help the scientists in this area to find topics for overcoming challenges together with engineers.展开更多
The effect of particle shape on the porosity and compressive strength of porous hydroxyapatite （HA） scaffolds was investigated by sintering the mixture of rod-shaped HA （r-HA） and spherical HA （s-HA） with polyac...The effect of particle shape on the porosity and compressive strength of porous hydroxyapatite （HA） scaffolds was investigated by sintering the mixture of rod-shaped HA （r-HA） and spherical HA （s-HA） with polyacrylamide used as the sacrificial template. It was found, for the first time, that addition of r-HA into s-HA could exponentially decrease the porosity of sintered HA scaffolds and enhance their compressive strength with the increase of r-HA content. The mechanism, according to the results from scanning electron microscopy and X-ray diffraction, lies in the restriction of s-HA to the grain formation and growth of r-HA during sintering and results in the fusion of r-HA with s-HA. These findings suggest that mixture of r-HA and s-HA might provide a new and facile way to improve the compressive strength of oorous HA scaffolds.展开更多
基金National Natural Science Foundation of China(Grant Nos.62335006,62022032,62275065,and 61875047)Key Laboratory of Opto-Electronic Information Acquisition and Manipulation(Anhui University),Ministry of Education(Grant No.OEIAM202202)Fundamental Research Funds for the Central Universities(Grant No.HIT.OCEF.2023011).
文摘A highly sensitive light-induced thermoelectric spectroscopy(LITES)sensor based on a multi-pass cell(MPC)with dense spot pattern and a novel quartz tuning fork(QTF)with low resonance frequency is reported in this manuscript.An erbi-um-doped fiber amplifier(EDFA)was employed to amplify the output optical power so that the signal level was further enhanced.The optical path length(OPL)and the ratio of optical path length to volume(RLV)of the MPC is 37.7 m and 13.8 cm^(-2),respectively.A commercial QTF and a self-designed trapezoidal-tip QTF with low frequency of 9461.83 Hz were used as the detectors of the sensor,respectively.The target gas selected to test the performance of the system was acetylene(C2H2).When the optical power was constant at 1000 mW,the minimum detection limit(MDL)of the C2H2-LITES sensor can be achieved 48.3 ppb when using the commercial QTF and 24.6 ppb when using the trapezoid-al-tip QTF.An improvement of the detection performance by a factor of 1.96 was achieved after replacing the commer-cial QTF with the trapezoidal-tip QTF.
基金financially supported by the Young Elite Scientist Sponsorship Program by CAST ( 2018QNRC001)the China Postdoctoral Science Foundation ( 2018M631172)
文摘It is necessary to investigate the characteristics of Mesenchymal stem cells(MSCs)derived exosomes,and especially their application in tissue regeneration.Previous studies have shown that inflammatory stimulation enhanced the secretion of MSC-derived exosomes with stronger anti-inflammatory protein,cytokine profiles,and functional RNA via altering COX2/PGE2 pathway.Recently,accumulating evidence has also revealed that biophysical cues(especially biomechanical cues)in cell microenvironment have significant effects not only on cells but also on their exosomes.It has been reported that applying bi-axial strain to MSCs induces formation of a stiffer cytoskeleton through mTORC2 signaling,which biases against adipogenic differentiation and toward osteoblastogenesis.At the same time,For example,dimensionality,composition and stiffness of the extracellular matrix(ECM)has been proved to affect the size and composition of exosomes secreted by cancer cells.However,the effects of biomechanical cues in the three-dimensional(3D)microenvironment on stem cell-derived exosomes remains to be unveiled.Therefore,it is important to understand the roles of 3D cell mechanical microenvironment in regulating the characteristics of stem cell-derived exosomes and develop more efficient approaches to enhance their functions.This study aimed to explore the changes in characteristics of exosomes secreted by MSCs in periodontium in response to the matrix strain in 3D.Periodontal ligament stem cells(PDLSCs)were cultured in a 3D strain microenvironment engineered with microscale magnetically stretched collagen hydrogels.The morphology,particle distribution,marker protein expression of PDLSC-derived exosomes were analyzed.Then the pro-osteogenic property of exosomes was evaluated by assessing cell viability,proliferation,migration and osteogenic differentiation of target cells,for instance human bone marrow mesenchymal stem cells(hBMSCs).Detailed characterizations revealed that PDLSC-derived exosomes in the 3D strain mi-croenvironment were with similar morphology,particle distribution and surface markers.Notably,Exosomes secreted by PDLSCs in strain microenvironment were more endocytosed by hBMSCs and were more potent in improving proliferation and migration of hBMSCs,comparing with PDLSCs in non-strain environment.Alizarin red staining and molecular biology experiments confirmed that treatment of exosomes secreted by PDLSCs under mechanical stimulation led to a significant increase in osteogenic differentiation of hBMSCs in vitro.Meanwhile,in vivo study also indicated that PDLSC-derived exosomes obtained from the 3D strain microenvironment could obviously promote new bone formation.Our findings revealed that mechanical cues profoundly affected the characteristics of PDLSC-derived exosomes,especially for their bio-activity,providing a foundation for using the 3D mechanical microenvironment to enhance the osteo-inductive functions of stem cell-derived exosomes in cell-free therapy for bone regeneration.
基金This work was supported by the National Natural Science Foundation of China(Grant No.U1601220)the National Natural Science Foundation of China(Grant No.82002310)+1 种基金the Chongqing Postgraduate Research and Innovation Project(Grant No.CYB20167)the Chongqing Postdoctoral Science Foundation(Grant No.csts2019jcyj-bsh0068).
文摘The limited bioactivity of scaffold materials is an important factor that restricts the development of bone tissue engineering.Wnt3a activates the classicWnt/β-catenin signaling pathway which effects bone growth and development by the accumulation ofβ-catenin in the nucleus.In this study,we fabricated 3D printed PCL scaffold with Wnt3a-induced murine bone marrow-derived stromal cell line ST2 decellularized matrix(Wnt3a-ST2-dCM-PCL)and ST2 decellularized matrix(ST2-dCM-PCL)by freeze-thaw cycle and DNase decellularization treatment which efficiently decellularized>90%DNA while preserved most protein.Compared to ST2-dCM-PCL,Wnt3a-ST2-dCM-PCL significantly enhanced newly-seeded ST2 proliferation,osteogenic differentiation and upregulated osteogenic marker genes alkaline phosphatase(Alp),Runx2,type I collagen(Col 1)and osteocalcin(Ocn)mRNA expression.After 14 days of osteogenic induction,Wnt3a-ST2-dCM-PCL promoted ST2 mineralization.These results demonstrated that Wnt3a-induced ST2 decellularized matrix improve scaffold materials’osteoinductivity and osteoconductivity.
基金National Natural Science Foundation of China U1601220(X.T.),81672118(X.T.),82072450(X.T.),82002310(Y.M.)Chongqing Science and Technology Commission—Basic Science and Frontier Technology Key Project cstc2015jcyjBX0119(X.T.)CQMU Program for Youth Innovation in Future Medicine,W0075(Y.M.).
文摘Cell source is the key to decellularized matrix(DM)strategy.This study compared 3 cell types,osteocytes with/without dominant active Wnt/β-catenin signaling(daCO and WTO)and bone marrow stromal cells(BMSCs)for their DMs in bone repair.Decellularization removes all organelles and>95%DNA,and retained>74%collagen and>71%GAG,maintains the integrity of cell basement membrane with dense boundaries showing oval and honeycomb structure in osteocytic DM and smooth but irregular shape in the BMSC-DM.DM produced higher cell survival rate(90%)and higher proliferative activity.In vitro,daCO-DM induces more and longer stress fibers in BMSCs,conducive to cell adhesion,spreading,and osteogenic differentiation.8-wk after implantation of the critical-sized parietal bone defect model,daCO-DM formed tight structures,composed of a large number of densely-arranged type-I collagen under polarized light microscope,which is similar to and integrated with host bone.BV/TV(>54%)was 1.5,2.9,and 3.5 times of WTO-DM,BMSC-DM,and none-DM groups,and N.Ob/T.Ar(3.2×10^(2)/mm^(2))was 1.7,2.9,and 3.3 times.At 4-wk,daCO-DM induced osteoclastogenesis,2.3 times higher than WTO-DM;but BMSC-DM or none-DM didn't.daCO-DM increased the expression of RANKL and MCSF,Vegfa and Angpt1,and Ngf in BMSCs,which contributes to osteoclastogenesis,angiogenesis,and neurogenesis,respectively.daCO-DM promoted H-type vessel formation and nerve markersβ3-tubulin and NeuN expression.Conclusion:daCO-DM produces metabolic and neurovascularized organoid bone to accelerate the repair of bone defects.These features are expected to achieve the effect of autologous bone transplantation,suitable for transformation application.
基金Supported by Nature Science Foundation of China under Contract NO.81101066
文摘Integrin αvβ3,a cell adhesion molecule,plays a key role in angiogenesis and tumor cell metastasis and is therefore an important target for new therapeutic and diagnostic strategies.Since RGD bind to αvβ3 particularly,a lot of RGD containing peptides were radiolabeled and evaluated as imaging or therapeutic agents.In this study,a new 188Re-RGD peptide analog was synthesized and characterized.Within 30min,the 188Re-H-E[c(RGDyK)]2 was obtained in radiochemical purity of better than 95%.The His-E[c(RGDyK)]2 had a good integrin-binding affinity (50% inhibitiory concentracer (IC50=46.5×10-9 nm) and exhibited active accumulation (7.20±1.06) in S180 tumor.Because of relatively fast washout in blood and normal tissues,the target/non-target ratio was high.Further experiments to improve the tumor targeting efficacy and in vivo kinetic profiles are in progress towards developing it into a promising radio agent.
基金supported by the National Natural Science Foundation of China(Nos.62335006,62022032,and 62275065)the Key Laboratory of Opto-Electronic Information Acquisition and Manipulation(Anhui University)+1 种基金Ministry of Education(No.OEIAM202202)the Fundamental Research Funds for the Central Universities(No.HIT.OCEF.2023011).
文摘A highly sensitive carbon dioxide(CO_(2))sensor based on light-induced thermoelastic spectroscopy(LITES)utilizing a selfdesigned low-frequency quartz tuning fork(QTF)and a fiber-coupled multipass cell(MPC)is reported in this paper.The QTF with a low resonant frequency of 8675 Hz and a high Q factor of 11,675.64 was used to improve its energy accumulation time and the sensor’s signal level.The MPC with the fiber-coupled structure and optical length of 40 m was adopted to significantly increase the gas absorbance and reduce the optical alignment difficulty as well as improve the robustness of the sensor system.A distributed feedback(DFB),near-infrared diode laser with an emission wavelength of 1.57μm was used as an excitation source.The experimental results showed that this CO_(2)-LITES sensor had an excellent linear response to CO_(2) concentrations.The minimum detection limitation(MDL)of this CO_(2)-LITES sensor was obtained to be 445.91 ppm,and it could be improved to 47.70 ppm(parts per million)when the integration time of the system reached 500 s.Further improvement methods for the detection performance of such sensors were also discussed.
基金the National Natural Science Foundation of China(Grant No.62335006,62022032,62275065,and 61875047)Key Laboratory of Opto-Electronic Information Acquisition and Manipulation(Anhui University),Ministry of Education(Grant No.OEIAM202202)Fundamental Research Funds for the Central Universities(Grant No.HIT.OCEF.2023011).
文摘Photoacoustic spectroscopy(PAS)as a highly sensitive and selective trace gas detection technique has extremely broad application in many fields.However,the laser sources currently used in PAS limit the sensing performance.Compared to diode laser and quantum cascade laser,the solid-state laser has the merits of high optical power,excellent beam quality,and wide tuning range.Here we present a long-wave,high-power,wide-tunable,singlelongitudinal-mode solid-state laser used as light source in a PAS sensor for trace gas detection.The self-built solid-state laser had an emission wavelength of~2μm with Tm:YAP crystal as the gain material,with an excellent wavelength and optical power stability as well as a high beam quality.The wide wavelength tuning range of 9.44 nm covers the absorption spectra of water and ammonia,with a maximum optical power of~130 mW,allowing dual gas detection with a single laser source.The solid-state laser was used as light source in three different photoacoustic detection techniques:standard PAS with microphone,and external-and intra-cavity quartz-enhanced photoacoustic spectroscopy(QEPAS),proving that solid-state laser is an attractive excitation source in photoacoustic spectroscopy.
基金supported by the National Science Foundation for Young Scientists of China(51802071)Advanced Talents Incubation Program of the Hebei University(521000981162)+3 种基金Outstanding Youth Science Foundation project of Hebei Province(A2020201032)Local Science and Technology Development Fund Projects Guided by the Central Government(206Z4403G)National Natural Science Foundation of China(No.51372064)Hebei Province High-level Talents Funding project(No.A201801003).
文摘Element doping and nano-inclusion embedding are effective approaches to enhance the electrical conductivities and decrease the lattice thermal conductivities of thermoelectric(TE)materials,respectively.However,the intrinsic low electrical thermal conductivities and high electrical properties are severely sacrificed,and the final figure of merit(ZT)is usually restricted.In this study,Ag doping and Pt quantum dot(QD)embedding were synchronously achieved via embedding Ag/Pt alloy QDs into the higher manganese silicides to avoid the conventional single-element doping strategy.The power factor(at 823 K)was enhanced from 1.57×10^(-3) W m^(-1) K^(-2) to 1.82×10^(-3) W m^(-1) K^(-2)(-16%)due to the-18%increase in carrier concentration that was derived from the Ag doping effect.Simultaneously,the lattice thermal conductivity(at 823 K)decreased from 2.65 W m^(-1) K^(-1) e1.92 W m^(-1) K^(-1)(-28%)because of the broadband phonon scattering effect that resulted from the residual Pt QDs inclusions.Synthetically,the optimal ZT value increased by-52%from 0.42 to 0.64 at 823 K.This study demonstrated that incorporating metastable alloy QDs to obtain element doping and nano-inclusion embedding effects is a novel and feasible means to enhance the ZT value of HMS.This method is also possibly applicable to other alloy QD/TE composites.
基金This work is supported by ZiQoo Chemical Co.Ltd.,Japan,and Hydrogen Energy Systems Society of Japan.Chen and Feng gratefully acknowledge the State Scholarship Fund of China Scholarship Council,China.Kitiphatpiboon gratefully acknowledges MEXT of Japan for the scholarship,Japan.
文摘Direct electrolytic splitting of seawater for the production of H2 using ocean energy is a promising technology that can help achieve carbon neutrality.However,owing to the high concentrations of chlorine ions in seawater,the chlorine evolution reaction always competes with the oxygen evolution reaction(OER)at the anode,and chloride corrosion occurs on both the anode and cathode.Thus,effective electrocatalysts with high selectivity toward the OER and excellent resistance to chloride corrosion should be developed.In this critical review,we focus on the prospects of state-of-the-art metal-oxide electrocatalysts,including noble metal oxides,non-noble metal oxides and their compounds,and spinel-and perovskite-type oxides,for seawater splitting.We elucidate their chemical properties,excellent OER selectivity,outstanding anti-chlorine-corrosion performance,and reaction mechanisms.In particular,we review metal oxides that operate at high current densities,near industrial application levels,based on special catalyst design strategies.
基金the National Natural Science Foundation of China(grant nos.62275065,62022032,61875047,and 61505041)Fundamental Research Funds for the Central Universities.
文摘As a new energy source,hydrogen(H_(2))detection is a hot topic in recent years.Because of the weak absorption characteristic,laser spectroscopy-based H_(2)detection is challenging.In this paper,a highly sensitive H_(2)sensor based on light-induced thermoelastic spectroscopy(LITES)technique is demonstrated for the first time.A continuous-wave,distributed feedback diode laser with emission in the 2.1μm region was adopted as the excitation source to target the strongest H_(2)absorption line of 4,712.90 cm^(−1).A Herriott multipass cell with an optical length of 10.1 m was chosen to further improve the H_(2)absorption.With the feature of processing the raw input data without data preprocessing and extracting the desired features automatically,the robust shallow neural network(SNN)fitting algorithm was brought in to denoise the sensor.For the LITES-based H_(2)sensor,the concentration response was tested,and an excellent linear response to H_(2)concentration levels was achieved.A minimum detection limit(MDL)of~80 ppm was obtained.On the basis of implementation of the H_(2)-LITES sensor,a heterodyne H_(2)-LITES sensor was further constructed to realize a fast measurement of resonance frequency of quartz tuning fork and H_(2)concentration simultaneously.The resonance frequency can be retrieved in several hundred milliseconds with the measurement accuracy of±0.2 Hz,and the result of 30,713.76 Hz is exactly same as the experimentally determined value of 30,713.69 Hz.After the SNN algorithm was applied,an MDL of~45 ppm was achieved for this heterodyne H_(2)-LITES sensor.
基金support from the National Natural Science Foundation of China(Grant Nos.62022032,62275065,61875047,61505041)the Key Laboratory of Opto-Electronic Information Acquisition and Manipulation(Anhui University)+1 种基金the Ministry of Education(Grant No.OEIAM202202)the Fundamental Research Funds for Central Universities.
文摘Fabry-Perot(F-P)-based phase demodulation of heterodyne light-induced thermoelastic spectroscopy(H-LITES)was demonstrated for the first time in this study.The vibration of a quartz tuning fork(QTF)was detected using the F-P interference principle instead of an electrical signal through the piezoelectric effect of the QTF in traditional LITES to avoid thermal noise.Given that an Fabry-Perot interferometer(FPI)is vulnerable to disturbances,a phase demodulation method that has been demonstrated theoretically and experimentally to be an effective solution for instability was used in H-LITES.The sensitivity of the F-P phase demodulation method based on the H-LITES sensor was not associated with the wavelength or power of the probe laser.Thus,stabilising the quadrature working point(Q-point)was no longer necessary.This new method of phase demodulation is structurally simple and was found to be resistant to interference from light sources and the surroundings using the LITES technique.
基金This work was supported by the National Natural Science Foundation of China(Nos.62022032,61875047,and 61505041)Natural Science Foundation of Heilongjiang Province of China(No.YQ2019F006)+1 种基金Fundamental Research Funds for the Central UniversitiesFinancial Grant from the Heilongjiang Province Postdoctoral Foundation(No.LBH-Q18052).
文摘sensor based on light-induced thermoelastic spectroscopy(LITES)with a fiber-coupled multipass cell was demonstrated for carbon monoxide(CO)detection.The fiber-coupled structure has the merits of reducing optical interference and difficulty in optical alignment and increasing system robustness.A 1.57 nm continuous wave distributed feedback diode laser was used as the excitation source.A minimum detection limit of 9 ppm was obtained,and the calculated normalized noise equivalent absorption coefficient was 1.15×10^(-7)cm^(-1)•W•Hz^(-1/2).The reported CO-LITES sensor showed excellent linear concentration response and system stability.
基金the National Natural Science Foundation of China(11805221)the Union Foundation of excellent post-doctoral of China Post-Doctoral Science Foundation and Chinese Science Academy(Y71I21)。
文摘Purpose In order to update the BPM electronic in BEPCII,a high-performance digital BPM processor is designed,and the RF front-end electronic is the key part in the digital BPM processor system.Methods According to the BEPCII physical parameters andADCunder-sampling theorem,the low-noise and high-dynamicrange RF front-end electronic module is designed.This article will introduce filter,RF amplifier,isolation,system test,etc.Results and conclusions The experimental results showed that BPM position short-term resolution is better than 100 nm,and long-term resolution is better than 5μm.It is the first domestic BPM processor that runs stably in the storage ring accelerator for a long time.Meanwhile,the study can help us to establish a solid foundation for the next work of BPM electronics development.
基金funded by grants from NCRCG-PLAGH-2022004the Military Healthcare Research Program(No.21BJZ26,18BJZ32).
文摘Background:Changes in thyroid hormone levels are commonly recognized characters among the elderly,which were reported to potentially influence incident frailty.Therefore,we examined the cross-sectional associations of thyroid hormones(THs)with frailty as well as the five components characterizing frailty(fatigue,resistance,ambulation,number ofillnesses,and loss of weight)among the oldest-old.Methods:Four hundred and eighty-seven community-dwelling oldest-old from a local community in Haidian District,Beijing,participated in our recruitment campaign between April 2019 and May 2020.The primary outcomes were a definitive diagnosis of frailty according to the FRAIL scale(Fatigue,Resistance,Ambulation,Illnesses,Loss of weight)and a positive score for each frailty subdomain.Demographic information(age,sex,marital status,and educational status),comorbidities,and details on the participants lifestyles were recorded.Serum THs including free triodothyronin(fT3),triiodothyronine(T3),free thyroxine(fT4),and thyroxine(T4)and thyroid stimulating hormone(TSH)levels were also measured at the beginning of our study.Logistic regressions were conducted to screen for potential risk factors for frailty and its subdomains.Results:Among the total 487 subjects at enrollment,60(12.23%)of them were diagnosed with subclinical hypothyroidism and 110(22.59%)of the total population scored positive for frailty.Logistic regression analyses adjusted for all potential confounders,showed that frailty was significantly associated with the serum TSH concentration(odds ratio[OR]:1.06),fT3 concentration(OR:0.54),and subclinical hypothyroidism score(OR:2.18).The association between fT4 and frailty was absent in our observational study.The fT3/fT4 ratio characterizing peripheral hormone conversion was also tested to be correlated with frailty.Conclusion:Subclinical hypothyroidism,higher TSH level,lower fT3 level,and decreased fT3/fT4 ratio were all associated with frailty assessed by the FRAIL scale among the community-dwelling oldest-old,suggesting a relevant role of thyroid function in aging.Future longitudinal studies are warranted to determine the casual relationship between thyroid dysfunction and frailty in the oldest-old.
基金This work was supported by the National Natural Science Foundation of China(51772282).
文摘Graphene oxide(GO)has demonstrated potential applications in various fields,and attracted intensive attention in industry as well.Numerous companies worldwide have been working on the industrial applications of GO-based materials in,e.g.,thermal management,multifunctional composites,anti-corrosion paints,lubricants,energy storage,environment protection and biomedicals.This review presents a short summary on the proceedings of GO towards industrialization,including the large-scale production and some promising applications,by providing views on the processing strategies and challenges specifically for the industrial use of GO.This review would help the scientists in this area to find topics for overcoming challenges together with engineers.
基金supported by the National Natural Science Foundation of China (Nos. 11532004 and 31370946)the National Science and Technology Support Program of China (No. 2012BAI17B03-4)+1 种基金the Development of Strategic Emerging Industries of Shenzhen Project (Nos. JCYJ20140417113430596 and CXZZ201404171134 30716)the Science and Technology Project of Guangdong Province (No. 2015A010105021)
文摘The effect of particle shape on the porosity and compressive strength of porous hydroxyapatite （HA） scaffolds was investigated by sintering the mixture of rod-shaped HA （r-HA） and spherical HA （s-HA） with polyacrylamide used as the sacrificial template. It was found, for the first time, that addition of r-HA into s-HA could exponentially decrease the porosity of sintered HA scaffolds and enhance their compressive strength with the increase of r-HA content. The mechanism, according to the results from scanning electron microscopy and X-ray diffraction, lies in the restriction of s-HA to the grain formation and growth of r-HA during sintering and results in the fusion of r-HA with s-HA. These findings suggest that mixture of r-HA and s-HA might provide a new and facile way to improve the compressive strength of oorous HA scaffolds.
