The transport of ablated particles produced by single pulsed-laser ablation is simulated via Monte Carlo method. The pressure ranges of velocity splitting of ablated particles in different inert gases are investigated...The transport of ablated particles produced by single pulsed-laser ablation is simulated via Monte Carlo method. The pressure ranges of velocity splitting of ablated particles in different inert gases are investigated. The result shows that the range of velocity splitting decreases with the atomic mass of the ambient gas increasing. The ambient gas whose atomic mass is more than that of Kr cannot induce the velocity splitting of ablated particles. The results are explained by the underdamping model and the inertia flow model.展开更多
The transport of hot electrons in inertial confinement fusion(ICF)is integrated issue due to the coupling of hydrodynamic evolution and many physical processes.A hot electron transport code is developed and coupled wi...The transport of hot electrons in inertial confinement fusion(ICF)is integrated issue due to the coupling of hydrodynamic evolution and many physical processes.A hot electron transport code is developed and coupled with the radiation hydrodynamic code MULTI1D in this study.Using the code,the slowing-down process and ablation process of the hot electron beam are simulated.The ablation pressure scaling law of hot electron beam is confirmed in our simulations.The hot electron transport is simulated in the radiation-ablated plasmas relevant to indirect-drive ICF,where the spatial profile of hot electron energy deposition is presented around the shock compressed region.It is shown that the hot electron can prominently increase the total ablation pressure in the early phase of radiation-ablated plasma.So,our study suggests that a potential-driven symmetric mechanism may occur under the irradiation of asymmetric hot electron beam.The possible degradation from the hot electron transport and preheating is also discussed.展开更多
A Monte Carlo simulation method with an instantaneous density dependent meanfree-path of the ablated particles and the Ar gas is developed for investigating the transport dynamics of the laser-ablated particles in a l...A Monte Carlo simulation method with an instantaneous density dependent meanfree-path of the ablated particles and the Ar gas is developed for investigating the transport dynamics of the laser-ablated particles in a low pressure inert gas.The ablated-particle density and velocity distributions are analyzed.The force distributions acting on the ablated particles are investigated.The influence of the substrate on the ablated-particle velocity distribution and the force distribution acting on the ablated particles are discussed.The Monte Carlo simulation results approximately agree with the experimental data at the pressure of 8 Pa to 17 Pa.This is helpful to investigate the gas phase nucleation and growth mechanism of nanoparticles.展开更多
AIM:To investigate whether tumor debris created by high-intensity focused ultrasound(HIFU)could trigger antitumor immunity in a mouse hepatocellular carcinoma model. METHODS:Twenty C57BL/6J mice bearing H22 hepatocell...AIM:To investigate whether tumor debris created by high-intensity focused ultrasound(HIFU)could trigger antitumor immunity in a mouse hepatocellular carcinoma model. METHODS:Twenty C57BL/6J mice bearing H22 hepatocellular carcinoma were used to generate antitumor vaccines.Ten mice underwent HIFU ablation,and the remaining 10 mice received a sham-HIFU procedure with no ultrasound irradiation.Sixty normal mice were randomly divided into HIFU vaccine,tumor vaccine and control groups.These mice were immunized with HIFU-generated vaccine,tumor-generated vaccine,and saline,respectively.In addition,20 mice bearing H22 tumors were successfully treated with HIFU ablation. The protective immunity of the vaccinated mice was investigated before and after a subsequent H22 tumor challenge.Using the 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide assay,the cytotoxicity of splenic lymphocytes co-cultured with H22 cells wasdetermined in vitro before the tumor challenge,and tumor volume and survival were measured in vivo after the challenge in each group.The mechanism was also explored by loading the vaccines with bone marrowderived dendritic cells(DCs). RESULTS:Compared to the control,HIFU therapy, tumor-generated and HIFU-generated vaccines significantly increased cytolytic activity against H22 cells in the splenocytes of the vaccinated mice(P<0.001). The tumor volume was significantly smaller in the HIFU vaccine group than in the tumor vaccine group(P <0.05)and control group(P<0.01).However,there was no tumor growth after H22 rechallenge in the HIFU therapy group.Forty-eight-day survival rate was 100%in mice in the HIFU therapy group,30%in both the HIFU vaccine and tumor vaccine groups,and 20% in the control group,indicating that the HIFU-treated mice displayed significantly longer survival than the vaccinated mice in the remaining three groups(P< 0.001).After bone marrow-derived DCs were incubated with HIFU-generated and tumor-generated vaccines, the number of mature DCs expressing MHC-Ⅱ + ,CD80 + and CD86 + molecules was significantly increased,and interleukin-12 and interferon-γlevels were significantly higher in the supernatants when compared with immature DCs incubated with mouse serum(P<0.001). However,no differences of the number of mature DCs and cytokine levels were observed between the HIFU- generated and tumor-generated vaccines(P>0.05). CONCLUSION:Tumor debris remaining after HIFU can improve tumor immunogenicity.This debris releases tumor antigens as an effective vaccine to develop host antitumor immune response after HIFU ablation.展开更多
Two dimensional(2D)materials are promising gas sensing materials,but the most of them need to be heated to show promising sensing performance.Sensing structures with high sensing performance at room-temperature are ur...Two dimensional(2D)materials are promising gas sensing materials,but the most of them need to be heated to show promising sensing performance.Sensing structures with high sensing performance at room-temperature are urgent.Here,another 2D material,violet phosphorus(VP)nanoflake is investigated as gas sensing material.The VP nanoflakes have been effectively ablated to have layers of 1–5 layers by laser ablation in glycol.The VP nanoflakes are combined with graphene to form VP/G heterostructuresbased NO sensor.An ultra-high gauge factor of 3×10^(7)for ppb-level sensing and high resistance response of 59.21%with ultra-short recovery time of 6s for ppm-level sensing have been obtained.The sensing mechanism is also analysed by density functional theory(DFT)calculations.The adsorption energy of VP/G is calculated to be-0.788 e V,resulting in electrons migration from P to N to form a P-N bond in the gap between VP and graphene sheet.This work provides a facile approach to ablate VP for mass production.The as-produced structures have also provided potential gas sensors with ultrasensitive performance as ppb-level room-temperature sensors.展开更多
The emission spectrum of AlO radicals was analyzed in 440-540 nm in the reaction of laser ablated Al beam and O 2. The carrier of spectrum was assigned to Δ ν =0, ±1, ±2 vibrational sequences of B ...The emission spectrum of AlO radicals was analyzed in 440-540 nm in the reaction of laser ablated Al beam and O 2. The carrier of spectrum was assigned to Δ ν =0, ±1, ±2 vibrational sequences of B 2Σ +-X 2Σ + transition of AlO radicals, the observed maximum vibrational quantum number was ν ′=6. The rotational and vibrational temperatures of B state were estimated at 3000 and 7500 K by spectrally simulating the rovibronic population distribution. There is a strong evidence that the production of excited Al( 2 S ) atoms is essential to the formation of excited AlO radicals.展开更多
Low energy metallic ions, generated by a Q-switched Nd：YAG laser （1064-nm wavelength, 10-mJ energy, 9-nm 12-ns-pulse width, 1011 W/cm2 intensity） irradiated on a silicon substrate to modify various properties, such...Low energy metallic ions, generated by a Q-switched Nd：YAG laser （1064-nm wavelength, 10-mJ energy, 9-nm 12-ns-pulse width, 1011 W/cm2 intensity） irradiated on a silicon substrate to modify various properties, such as electrical, morphological, and structural modifications. Thomson parabola technique is used to calculate the energy of these metallic ions whereas the electrical conductivity is calculated with the help of Four-point probe. Interestingly circular tracks forming chain like damage trails are produced via these energetic ions which are carefully examined by optical microscopy. It is observed that excitation, ionization, and cascade collisions are responsible for surface modifications of irradiated samples. Four-point probe analysis revealed that the electrical conductivity of substrate has reduced with increasing trend of atomic number of irradiated metallic ions （A1, Ti, Cu, and Au）. The x-ray diffraction analysis elucidated the crystallographic changes leading to reduction of grain size of N-type silicon substrate, which is also associated with the metallic ions used. The decreasing trend of conductivity and grain size is due to thermal stresses, scattering effect, structural imperfections, and non-uniform conduction of energy absorbed by substrate atoms after the ion irradiation.展开更多
Laser ablated high temperature superconducting and related thin films are investigated with a microscopical point of view.The microstructure and microchemistry of three thin films(Y-Ba-Cu-O, Bi-Pb-Sr-Ca-Cu-O and Sr-Ca...Laser ablated high temperature superconducting and related thin films are investigated with a microscopical point of view.The microstructure and microchemistry of three thin films(Y-Ba-Cu-O, Bi-Pb-Sr-Ca-Cu-O and Sr-Ca-Cu-O)are demonstrated as examples of laser ablation products.展开更多
Thermal characteristics of tightly-contacted copper-gold double-layer thin film target under ablation of femtosec- ond laser pulses are investigated by using a two-temperature theoretical model. Numerical simulation s...Thermal characteristics of tightly-contacted copper-gold double-layer thin film target under ablation of femtosec- ond laser pulses are investigated by using a two-temperature theoretical model. Numerical simulation shows that electron heat flux varies significantly on the boundary of copper-gold film with different maximal electron temperature of 1.15 x 103 K at 5 ps after ablating laser pulse in gold and copper films, which can reach a balance around 12.6 ps and 8.2 ps for a single and double pulse ablation, respectively, and in the meantime, the lattice temperature difference crossing the gold-copper interface is only about 0.04×103 K at the same time scale. It is also found that electron-lattice heat relaxation time increases linearly with laser fluence in both single and double pulse ablation, and a sudden change of the relaxation time appears after the laser energy density exceeds the ablation threshold.展开更多
Al-doped ZnO（AZO） thin films were grown on c-sapphire substrates by laser ablation under different oxygen partial pressures（P_（O2））.The effect of P_（O2） on the crystal structure,preferred orientation as well a...Al-doped ZnO（AZO） thin films were grown on c-sapphire substrates by laser ablation under different oxygen partial pressures（P_（O2））.The effect of P_（O2） on the crystal structure,preferred orientation as well as the electrical and optical properties of the films was investigated.The structure characterizations indicated that the as-grown films were single-phased with a wurtzite ZnO structure,showing a significant c-axis orientation.The films were well crystallized and exhibited better crystallinity and denser texture when deposited at higher P_（O2）.At the optimum oxygen partial pressures of 10- 15 Pa,the AZO thin films were epitaxially grown on c-sapphire substrates with the（0001） plane parallel to the substrate surface,i e,the epitaxial relationship was AZO（000 1） // A1_2O_3（000 1）.With increasing P_（O2）,the value of Hall carrier mobility was increased remarkably while that of carrier concentration was decreased slightly,which led to an enhancement in electrical conductivity of the AZO thin films.All the films were highly transparent with an optical transmittance higher than 85%.展开更多
We experimentally and numerically investigated the hydrodynamics,fragmentation mechanisms,and debris distribution arising from the interaction of nanosecond laser pulses with a gallium-indium-tin(Ga-In-Sn)liquid film ...We experimentally and numerically investigated the hydrodynamics,fragmentation mechanisms,and debris distribution arising from the interaction of nanosecond laser pulses with a gallium-indium-tin(Ga-In-Sn)liquid film of micron-scale thickness.Highspeed stroboscopic shadow photography was employed to visualize the splash crown and ejection of debris.The velocities of this debris,ranging from 329 to 4211 m s^(-1),were found to scale with laser pulse energy(E_(p)=0.9-36 m J)and film thickness(h)according to U∝E^(5/9)_(p)/h.This velocity was accurately described by a modified ablation and propulsion model.The numerical simulations provided insights into the underlying physics,including the expansion of high-pressure plasma zone,shock wave propagation,and the formation of significant negative pressure regions conducive to cavitation.Furthermore,the direction of minimal debris deposition is found to align with peak plasma luminous intensity,which is normal to the liquid film.展开更多
Flexible triboelectric nanogenerators (TENGs)-based pressure sensors are very essential for the wide-range applications, comprising wearable healthcare systems, intuitive human-device interfaces, electronic-skin (e-sk...Flexible triboelectric nanogenerators (TENGs)-based pressure sensors are very essential for the wide-range applications, comprising wearable healthcare systems, intuitive human-device interfaces, electronic-skin (e-skin), and artificial intelligence. Most of conventional fabrication methods used to produce high-performance TENGs involve plasma treatment, photolithography, printing, and electro-deposition. However, these fabrication techniques are expensive, multi-step, time-consuming and not suitable for mass production, which are the main barriers for efficient and cost-effective commercialization of TENGs. Here, we established a highly reliable scheme for the fabrication of a novel eco-friendly, low cost, and TENG-based pressure sensor (TEPS) designed for usage in self-powered-human gesture detection (SP-HGD) likewise wearable healthcare applications. The sensors with microstructured electrodes performed well with high sensitivity (7.697 kPa^-1), a lower limit of detection (~ 1 Pa), faster response time (< 9.9 ms), and highly stable over > 4,000 compression-releasing cycles. The proposed method is suitable for the adaptable fabrication of TEPS at an extremely low cost with possible applications in self-powered systems, especially e-skin and healthcare applications.展开更多
Interleukin 12(IL-12)and/or interleukin 18(IL-18)gene ablated mice were applied for the investigation of the tissue expression of interferon γ(IFN-γ).For IL-12^(-/-),IL-18^(-/-),IL-12^(-/-)/18^(-/-) and wt mice,repr...Interleukin 12(IL-12)and/or interleukin 18(IL-18)gene ablated mice were applied for the investigation of the tissue expression of interferon γ(IFN-γ).For IL-12^(-/-),IL-18^(-/-),IL-12^(-/-)/18^(-/-) and wt mice,reproductive performance were recorded and IFN-γ concentrations in heart,lung,liver,spleen,kidney and serum were quantified by ELISA. There were no significant differences of IFN-γ in heart,lung and kidney between 4 strains although control group was higher.It was observed that for IL-12^(-/-) mice,compared with other 3 groups,IFN-γ in liver and spleen were decreased(p<0.05)and reproductive performance appeared to be impaired.Serum IFN-γ level of IL-12^(-/-)/18^(-/-) mice was significantly higher(p<0.05).It was showed that IFN-γ productions under the normal condition were independent upon IL-12 and IL-18,its expressions in various tissues were different,and optimal IFN-γ is necessary for the normal growth and development of mammals.This study is helpful for clinical cytokines therapy.Cellular & Molecular Immunology.2005;2(1):68-72.展开更多
Radiofrequency ablation(RFA),particularly endoscopic ultrasound-guided RFA(EUS-RFA),has emerged as a promising minimally invasive approach for the treatment of pancreatic cancer,especially in patients with locally adv...Radiofrequency ablation(RFA),particularly endoscopic ultrasound-guided RFA(EUS-RFA),has emerged as a promising minimally invasive approach for the treatment of pancreatic cancer,especially in patients with locally advanced or unresectable disease.This review outlines recent technological developments in EUS-RFA,including innovations in energy delivery systems,probe design,and real-time thermal monitoring,which have improved the precision and safety of the procedure.Clinical studies combining EUS-RFA with chemotherapy have demonstrated encouraging outcomes,with improvements in overall survival,progression-free survival,tumor necrosis,and symptom control compared to chemotherapy alone.Additionally,RFA-induced tumor antigen release and modulation of the tumor microenvironment suggest a potential synergistic role with immunotherapy.Despite its promise,the widespread adoption of EUS-RFA is limited by a lack of large-scale randomized controlled trials and standardized treatment protocols.展开更多
BACKGROUND Data comparing the outcomes of hepatocellular carcinoma(HCC)ablation by multibipolar radiofrequency ablation(mbp-RFA)and microwave ablation(MWA)are lacking.This study compares safety and efficacy of the two...BACKGROUND Data comparing the outcomes of hepatocellular carcinoma(HCC)ablation by multibipolar radiofrequency ablation(mbp-RFA)and microwave ablation(MWA)are lacking.This study compares safety and efficacy of the two techniques in treatment-naive HCC.AIM To compare the risk of local tumor progression(LTP)according to the technique;secondary endpoints included technique efficacy rate at one-month,overall survival and major complication rate.METHODS A bi-institutional retrospective analysis of patients undergoing treatment-naive HCC ablation by either technique was performed.Inverse probability of treatment weighting was used to compare the two groups.Mixed effects multivariate Cox regression was applied to identify risk factors for LTP.RESULTS A total of 362 patients(mean age,66.1±6.2 years,308 men)were included,of which 242(323 tumors)treated by mbp-RFA and 120(168 tumors)by MWA.After a median follow-up of 27 months,cumulative LTP was 11.4%after mbp-RFA and 25.2%after MWA.Independent risk factors for LTP at multivariate analysis were MWA(hazard ratio=2.85,P<0.001)and tumor size(hazard ratio=1.08,P<0.001).Two-year LTP-free survival was higher after mbp-RFA than MWA regardless of size(<3 cm:96%vs 87.1%,P<0.01;≥3 cm:87.5%vs 74%,P=0.04).Technique efficacy rate was higher after mbp-RFA(94.1%vs 87.5%,P=0.01).No difference was observed in major complication rate(9.5%vs 7.5%,P=0.59),nor 5-year overall survival(63.6%vs 58.3%,P=0.33).CONCLUSION Mbp-RFA leads to better local tumor control of treatment-naïve HCC than MWA regardless of tumor size and has better primary efficacy,while maintaining a comparable safety profile.展开更多
Alkali metal thermochemical ablation is a promising anti-tumor therapy in which tumor tissue can be efficiently destroyed via both heat and hydroxyl ions released from the chemical reaction in tissue between an alkali...Alkali metal thermochemical ablation is a promising anti-tumor therapy in which tumor tissue can be efficiently destroyed via both heat and hydroxyl ions released from the chemical reaction in tissue between an alkali metal and water. Encouraging results have been reported from in vitro and in vivo trials in a previous study. However, the precise process of heat and mass transfer triggered by the above thermochemical reaction in tumor tissue has still remained confusing. Here, to better understand the temperature and p H responses of tumor tissue subject to alkali metal therapy, a theoretical model coupling temperature and concentration field is developed for characterizing the physicochemical reaction and the transport process occurring around the inserted sodium capsule during treatment. Preliminary experiments in tumor tissue are performed to validate the theoretical predictions of temperature, and the results indicate that the bioheat transfer model can predict the temperature responses in the tissues heated by the sodium capsule very well. Furthermore, comprehensive parametric studies are performed to evaluate the effects of either physiological or physicochemical parameters, including ablation time, time lags, and blood perfusion rate. Based on the numerical results, useful instructions are suggested for planning alkali metal tumor ablation treatment.展开更多
Microwave ablation(MWA)is a minimally invasive technique for treating hepatic tumors,necessitating precise monitoring to ensure treatment efficacy and minimize damage to surrounding tissues.This study explores the pot...Microwave ablation(MWA)is a minimally invasive technique for treating hepatic tumors,necessitating precise monitoring to ensure treatment efficacy and minimize damage to surrounding tissues.This study explores the potential of photoacoustic imaging(PAI)in monitoring MWA by examining ex vivo porcine liver tissues.In this study,a comprehensive analysis of photoacoustic signals was performed to compare the main lobe width(MLW)between ablated and normal regions in porcine liver tissue.Histological staining with succinate dehydrogenase(SDH)and shear wave elastography(SWE)were employed to validate the changes in tissue elasticity after ablation.The analysis demonstrated a notable reduction in the MLW of the average A-lines in ablated tissues compared to nonablated regions(p<0.01).This reduction,attributed to increased tissue density and enhanced elasticity,indicates accelerated sound propagation in thermally ablated areas,which then serves as a critical parameter for mapping tissue characteristics.The reconstruction of the MLW distribution successfully delineated the ablated regions,and was consistent with the results of SDH staining and SWE.In addition,MLW-based imaging exhibited higher spatial resolution compared to SWE.Incorporating MLW analysis into PAI may be a promising strategy to improve the accuracy and effectiveness of MWA monitoring in clinical settings.展开更多
Colorectal cancer(CRC)with lung oligometastases,particularly in the presence of extrapulmonary disease,poses considerable therapeutic challenges in clinical practice.We have carefully studied the multicenter study by ...Colorectal cancer(CRC)with lung oligometastases,particularly in the presence of extrapulmonary disease,poses considerable therapeutic challenges in clinical practice.We have carefully studied the multicenter study by Hu et al,which evaluated the survival outcomes of patients with metastatic CRC who received image-guided thermal ablation(IGTA).These findings provide valuable clinical evidence supporting IGTA as a feasible,minimally invasive approach and underscore the prognostic significance of metastatic distribution.However,the study by Hu et al has several limitations,including that not all pulmonary lesions were pathologically confirmed,postoperative follow-up mainly relied on dynamic contrast-enhanced computed tomography,no comparative analysis was performed with other local treatments,and the impact of other imaging features on efficacy and prognosis was not evaluated.Future studies should include complete pathological confirmation,integrate functional imaging and radiomics,and use prospective multicenter collaboration to optimize patient selection standards for IGTA treatment,strengthen its clinical evidence base,and ultimately promote individualized decision-making for patients with metastatic CRC.展开更多
Over the past ten years,numerous papers have been published on the use of indocyanine green(ICG)fluorescence in liver surgery for hepatocellular carcinoma(HCC).There are many different applications.The first involves ...Over the past ten years,numerous papers have been published on the use of indocyanine green(ICG)fluorescence in liver surgery for hepatocellular carcinoma(HCC).There are many different applications.The first involves targeting superficial tumors in patients with macronodular cirrhosis and an irregular liver surface.In a minimally invasive setting,the lack of tactile feedback on the hepatic surface makes detecting subcapsular HCC with ultrasound alone challenging.ICG fusion images can mimic the tactile feedback of the hand and act as an ultrasound booster.ICG fluorescence can be used to evaluate tumor residues after minimally invasive thermal ablation.ICG fluorescence imaging can also be used to identify the grade of HCC early on and evaluate the microinvasive component.展开更多
Hafnium carbide(HfC)serves as a critical ablation-resistant coating for C/C composites used on the wing leading edges of high-speed vehicles during atmospheric re-entry[1-3].Under the action of high-temperature,oxidiz...Hafnium carbide(HfC)serves as a critical ablation-resistant coating for C/C composites used on the wing leading edges of high-speed vehicles during atmospheric re-entry[1-3].Under the action of high-temperature,oxidizing gas flow,the HfC coating forms a high-melting-point heterogeneous oxide layer,significantly delaying oxidation of the underlying material and preserving the structural integrity of the C/C composites[4].展开更多
基金supported by the National Basic Research Program of China(Grant No.2011CB612305)the Natural Science Foundation of Hebei Province,China(Grant Nos.E2012201035 and E2011201134)
文摘The transport of ablated particles produced by single pulsed-laser ablation is simulated via Monte Carlo method. The pressure ranges of velocity splitting of ablated particles in different inert gases are investigated. The result shows that the range of velocity splitting decreases with the atomic mass of the ambient gas increasing. The ambient gas whose atomic mass is more than that of Kr cannot induce the velocity splitting of ablated particles. The results are explained by the underdamping model and the inertia flow model.
基金Project supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA25050600)the DCI joint team。
文摘The transport of hot electrons in inertial confinement fusion(ICF)is integrated issue due to the coupling of hydrodynamic evolution and many physical processes.A hot electron transport code is developed and coupled with the radiation hydrodynamic code MULTI1D in this study.Using the code,the slowing-down process and ablation process of the hot electron beam are simulated.The ablation pressure scaling law of hot electron beam is confirmed in our simulations.The hot electron transport is simulated in the radiation-ablated plasmas relevant to indirect-drive ICF,where the spatial profile of hot electron energy deposition is presented around the shock compressed region.It is shown that the hot electron can prominently increase the total ablation pressure in the early phase of radiation-ablated plasma.So,our study suggests that a potential-driven symmetric mechanism may occur under the irradiation of asymmetric hot electron beam.The possible degradation from the hot electron transport and preheating is also discussed.
基金supported by the Natural Science Foundation of Hebei Province,China(No.A2015201166)the Natural Science Foundation of Hebei University,China(No.2013-252)
文摘A Monte Carlo simulation method with an instantaneous density dependent meanfree-path of the ablated particles and the Ar gas is developed for investigating the transport dynamics of the laser-ablated particles in a low pressure inert gas.The ablated-particle density and velocity distributions are analyzed.The force distributions acting on the ablated particles are investigated.The influence of the substrate on the ablated-particle velocity distribution and the force distribution acting on the ablated particles are discussed.The Monte Carlo simulation results approximately agree with the experimental data at the pressure of 8 Pa to 17 Pa.This is helpful to investigate the gas phase nucleation and growth mechanism of nanoparticles.
基金Supported by The Foundation of Ministry of Education of China,No.IRT0454
文摘AIM:To investigate whether tumor debris created by high-intensity focused ultrasound(HIFU)could trigger antitumor immunity in a mouse hepatocellular carcinoma model. METHODS:Twenty C57BL/6J mice bearing H22 hepatocellular carcinoma were used to generate antitumor vaccines.Ten mice underwent HIFU ablation,and the remaining 10 mice received a sham-HIFU procedure with no ultrasound irradiation.Sixty normal mice were randomly divided into HIFU vaccine,tumor vaccine and control groups.These mice were immunized with HIFU-generated vaccine,tumor-generated vaccine,and saline,respectively.In addition,20 mice bearing H22 tumors were successfully treated with HIFU ablation. The protective immunity of the vaccinated mice was investigated before and after a subsequent H22 tumor challenge.Using the 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide assay,the cytotoxicity of splenic lymphocytes co-cultured with H22 cells wasdetermined in vitro before the tumor challenge,and tumor volume and survival were measured in vivo after the challenge in each group.The mechanism was also explored by loading the vaccines with bone marrowderived dendritic cells(DCs). RESULTS:Compared to the control,HIFU therapy, tumor-generated and HIFU-generated vaccines significantly increased cytolytic activity against H22 cells in the splenocytes of the vaccinated mice(P<0.001). The tumor volume was significantly smaller in the HIFU vaccine group than in the tumor vaccine group(P <0.05)and control group(P<0.01).However,there was no tumor growth after H22 rechallenge in the HIFU therapy group.Forty-eight-day survival rate was 100%in mice in the HIFU therapy group,30%in both the HIFU vaccine and tumor vaccine groups,and 20% in the control group,indicating that the HIFU-treated mice displayed significantly longer survival than the vaccinated mice in the remaining three groups(P< 0.001).After bone marrow-derived DCs were incubated with HIFU-generated and tumor-generated vaccines, the number of mature DCs expressing MHC-Ⅱ + ,CD80 + and CD86 + molecules was significantly increased,and interleukin-12 and interferon-γlevels were significantly higher in the supernatants when compared with immature DCs incubated with mouse serum(P<0.001). However,no differences of the number of mature DCs and cytokine levels were observed between the HIFU- generated and tumor-generated vaccines(P>0.05). CONCLUSION:Tumor debris remaining after HIFU can improve tumor immunogenicity.This debris releases tumor antigens as an effective vaccine to develop host antitumor immune response after HIFU ablation.
基金the funding support by National Natural Science Foundation of China(Nos.61705125,22175136)Open Foundation of State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures,Guangxi University(No.2022GXYSOF15)。
文摘Two dimensional(2D)materials are promising gas sensing materials,but the most of them need to be heated to show promising sensing performance.Sensing structures with high sensing performance at room-temperature are urgent.Here,another 2D material,violet phosphorus(VP)nanoflake is investigated as gas sensing material.The VP nanoflakes have been effectively ablated to have layers of 1–5 layers by laser ablation in glycol.The VP nanoflakes are combined with graphene to form VP/G heterostructuresbased NO sensor.An ultra-high gauge factor of 3×10^(7)for ppb-level sensing and high resistance response of 59.21%with ultra-short recovery time of 6s for ppm-level sensing have been obtained.The sensing mechanism is also analysed by density functional theory(DFT)calculations.The adsorption energy of VP/G is calculated to be-0.788 e V,resulting in electrons migration from P to N to form a P-N bond in the gap between VP and graphene sheet.This work provides a facile approach to ablate VP for mass production.The as-produced structures have also provided potential gas sensors with ultrasensitive performance as ppb-level room-temperature sensors.
基金Supported by the National Natural Science Foundation of China( No.2 0 0 730 4 2 )
文摘The emission spectrum of AlO radicals was analyzed in 440-540 nm in the reaction of laser ablated Al beam and O 2. The carrier of spectrum was assigned to Δ ν =0, ±1, ±2 vibrational sequences of B 2Σ +-X 2Σ + transition of AlO radicals, the observed maximum vibrational quantum number was ν ′=6. The rotational and vibrational temperatures of B state were estimated at 3000 and 7500 K by spectrally simulating the rovibronic population distribution. There is a strong evidence that the production of excited Al( 2 S ) atoms is essential to the formation of excited AlO radicals.
文摘Low energy metallic ions, generated by a Q-switched Nd：YAG laser （1064-nm wavelength, 10-mJ energy, 9-nm 12-ns-pulse width, 1011 W/cm2 intensity） irradiated on a silicon substrate to modify various properties, such as electrical, morphological, and structural modifications. Thomson parabola technique is used to calculate the energy of these metallic ions whereas the electrical conductivity is calculated with the help of Four-point probe. Interestingly circular tracks forming chain like damage trails are produced via these energetic ions which are carefully examined by optical microscopy. It is observed that excitation, ionization, and cascade collisions are responsible for surface modifications of irradiated samples. Four-point probe analysis revealed that the electrical conductivity of substrate has reduced with increasing trend of atomic number of irradiated metallic ions （A1, Ti, Cu, and Au）. The x-ray diffraction analysis elucidated the crystallographic changes leading to reduction of grain size of N-type silicon substrate, which is also associated with the metallic ions used. The decreasing trend of conductivity and grain size is due to thermal stresses, scattering effect, structural imperfections, and non-uniform conduction of energy absorbed by substrate atoms after the ion irradiation.
文摘Laser ablated high temperature superconducting and related thin films are investigated with a microscopical point of view.The microstructure and microchemistry of three thin films(Y-Ba-Cu-O, Bi-Pb-Sr-Ca-Cu-O and Sr-Ca-Cu-O)are demonstrated as examples of laser ablation products.
基金supported by the National Natural Science Foundation of China (Grant No. 60978014)the Natural Science Foundation of Jilin Province (Grant No. 20090523)the Educational Commission of Jilin Province (Grant No. [2008]297)
文摘Thermal characteristics of tightly-contacted copper-gold double-layer thin film target under ablation of femtosec- ond laser pulses are investigated by using a two-temperature theoretical model. Numerical simulation shows that electron heat flux varies significantly on the boundary of copper-gold film with different maximal electron temperature of 1.15 x 103 K at 5 ps after ablating laser pulse in gold and copper films, which can reach a balance around 12.6 ps and 8.2 ps for a single and double pulse ablation, respectively, and in the meantime, the lattice temperature difference crossing the gold-copper interface is only about 0.04×103 K at the same time scale. It is also found that electron-lattice heat relaxation time increases linearly with laser fluence in both single and double pulse ablation, and a sudden change of the relaxation time appears after the laser energy density exceeds the ablation threshold.
基金Funded by National Natural Science Foundation of China(Nos.51272195,51521001)111 project(No.B13035)+1 种基金Hubei Provincial National Natural Science Foundation(No.2015CFB724)Fundamental Research Funds for the Central Universities(Nos.2013-ZD-4,2014-KF-3)
文摘Al-doped ZnO（AZO） thin films were grown on c-sapphire substrates by laser ablation under different oxygen partial pressures（P_（O2））.The effect of P_（O2） on the crystal structure,preferred orientation as well as the electrical and optical properties of the films was investigated.The structure characterizations indicated that the as-grown films were single-phased with a wurtzite ZnO structure,showing a significant c-axis orientation.The films were well crystallized and exhibited better crystallinity and denser texture when deposited at higher P_（O2）.At the optimum oxygen partial pressures of 10- 15 Pa,the AZO thin films were epitaxially grown on c-sapphire substrates with the（0001） plane parallel to the substrate surface,i e,the epitaxial relationship was AZO（000 1） // A1_2O_3（000 1）.With increasing P_（O2）,the value of Hall carrier mobility was increased remarkably while that of carrier concentration was decreased slightly,which led to an enhancement in electrical conductivity of the AZO thin films.All the films were highly transparent with an optical transmittance higher than 85%.
基金supported by the National Natural Science Foundation of China(Grant Nos.12327803,12588301,and 62475111)。
文摘We experimentally and numerically investigated the hydrodynamics,fragmentation mechanisms,and debris distribution arising from the interaction of nanosecond laser pulses with a gallium-indium-tin(Ga-In-Sn)liquid film of micron-scale thickness.Highspeed stroboscopic shadow photography was employed to visualize the splash crown and ejection of debris.The velocities of this debris,ranging from 329 to 4211 m s^(-1),were found to scale with laser pulse energy(E_(p)=0.9-36 m J)and film thickness(h)according to U∝E^(5/9)_(p)/h.This velocity was accurately described by a modified ablation and propulsion model.The numerical simulations provided insights into the underlying physics,including the expansion of high-pressure plasma zone,shock wave propagation,and the formation of significant negative pressure regions conducive to cavitation.Furthermore,the direction of minimal debris deposition is found to align with peak plasma luminous intensity,which is normal to the liquid film.
文摘Flexible triboelectric nanogenerators (TENGs)-based pressure sensors are very essential for the wide-range applications, comprising wearable healthcare systems, intuitive human-device interfaces, electronic-skin (e-skin), and artificial intelligence. Most of conventional fabrication methods used to produce high-performance TENGs involve plasma treatment, photolithography, printing, and electro-deposition. However, these fabrication techniques are expensive, multi-step, time-consuming and not suitable for mass production, which are the main barriers for efficient and cost-effective commercialization of TENGs. Here, we established a highly reliable scheme for the fabrication of a novel eco-friendly, low cost, and TENG-based pressure sensor (TEPS) designed for usage in self-powered-human gesture detection (SP-HGD) likewise wearable healthcare applications. The sensors with microstructured electrodes performed well with high sensitivity (7.697 kPa^-1), a lower limit of detection (~ 1 Pa), faster response time (< 9.9 ms), and highly stable over > 4,000 compression-releasing cycles. The proposed method is suitable for the adaptable fabrication of TEPS at an extremely low cost with possible applications in self-powered systems, especially e-skin and healthcare applications.
文摘Interleukin 12(IL-12)and/or interleukin 18(IL-18)gene ablated mice were applied for the investigation of the tissue expression of interferon γ(IFN-γ).For IL-12^(-/-),IL-18^(-/-),IL-12^(-/-)/18^(-/-) and wt mice,reproductive performance were recorded and IFN-γ concentrations in heart,lung,liver,spleen,kidney and serum were quantified by ELISA. There were no significant differences of IFN-γ in heart,lung and kidney between 4 strains although control group was higher.It was observed that for IL-12^(-/-) mice,compared with other 3 groups,IFN-γ in liver and spleen were decreased(p<0.05)and reproductive performance appeared to be impaired.Serum IFN-γ level of IL-12^(-/-)/18^(-/-) mice was significantly higher(p<0.05).It was showed that IFN-γ productions under the normal condition were independent upon IL-12 and IL-18,its expressions in various tissues were different,and optimal IFN-γ is necessary for the normal growth and development of mammals.This study is helpful for clinical cytokines therapy.Cellular & Molecular Immunology.2005;2(1):68-72.
文摘Radiofrequency ablation(RFA),particularly endoscopic ultrasound-guided RFA(EUS-RFA),has emerged as a promising minimally invasive approach for the treatment of pancreatic cancer,especially in patients with locally advanced or unresectable disease.This review outlines recent technological developments in EUS-RFA,including innovations in energy delivery systems,probe design,and real-time thermal monitoring,which have improved the precision and safety of the procedure.Clinical studies combining EUS-RFA with chemotherapy have demonstrated encouraging outcomes,with improvements in overall survival,progression-free survival,tumor necrosis,and symptom control compared to chemotherapy alone.Additionally,RFA-induced tumor antigen release and modulation of the tumor microenvironment suggest a potential synergistic role with immunotherapy.Despite its promise,the widespread adoption of EUS-RFA is limited by a lack of large-scale randomized controlled trials and standardized treatment protocols.
文摘BACKGROUND Data comparing the outcomes of hepatocellular carcinoma(HCC)ablation by multibipolar radiofrequency ablation(mbp-RFA)and microwave ablation(MWA)are lacking.This study compares safety and efficacy of the two techniques in treatment-naive HCC.AIM To compare the risk of local tumor progression(LTP)according to the technique;secondary endpoints included technique efficacy rate at one-month,overall survival and major complication rate.METHODS A bi-institutional retrospective analysis of patients undergoing treatment-naive HCC ablation by either technique was performed.Inverse probability of treatment weighting was used to compare the two groups.Mixed effects multivariate Cox regression was applied to identify risk factors for LTP.RESULTS A total of 362 patients(mean age,66.1±6.2 years,308 men)were included,of which 242(323 tumors)treated by mbp-RFA and 120(168 tumors)by MWA.After a median follow-up of 27 months,cumulative LTP was 11.4%after mbp-RFA and 25.2%after MWA.Independent risk factors for LTP at multivariate analysis were MWA(hazard ratio=2.85,P<0.001)and tumor size(hazard ratio=1.08,P<0.001).Two-year LTP-free survival was higher after mbp-RFA than MWA regardless of size(<3 cm:96%vs 87.1%,P<0.01;≥3 cm:87.5%vs 74%,P=0.04).Technique efficacy rate was higher after mbp-RFA(94.1%vs 87.5%,P=0.01).No difference was observed in major complication rate(9.5%vs 7.5%,P=0.59),nor 5-year overall survival(63.6%vs 58.3%,P=0.33).CONCLUSION Mbp-RFA leads to better local tumor control of treatment-naïve HCC than MWA regardless of tumor size and has better primary efficacy,while maintaining a comparable safety profile.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No.XDB1030000)the Beijing United Fund (Grant No.L252063)。
文摘Alkali metal thermochemical ablation is a promising anti-tumor therapy in which tumor tissue can be efficiently destroyed via both heat and hydroxyl ions released from the chemical reaction in tissue between an alkali metal and water. Encouraging results have been reported from in vitro and in vivo trials in a previous study. However, the precise process of heat and mass transfer triggered by the above thermochemical reaction in tumor tissue has still remained confusing. Here, to better understand the temperature and p H responses of tumor tissue subject to alkali metal therapy, a theoretical model coupling temperature and concentration field is developed for characterizing the physicochemical reaction and the transport process occurring around the inserted sodium capsule during treatment. Preliminary experiments in tumor tissue are performed to validate the theoretical predictions of temperature, and the results indicate that the bioheat transfer model can predict the temperature responses in the tissues heated by the sodium capsule very well. Furthermore, comprehensive parametric studies are performed to evaluate the effects of either physiological or physicochemical parameters, including ablation time, time lags, and blood perfusion rate. Based on the numerical results, useful instructions are suggested for planning alkali metal tumor ablation treatment.
基金supported by the National Natural Science Foundation of China(82427808,61875085)the Jiangsu Provincial University Natural Science Foundation(25KJB413004)+1 种基金the Nanjing Health Science and Technology Development Foundation(ZKX24043)the Fundamental Research Funds for the Central Universities(NJ2024029).
文摘Microwave ablation(MWA)is a minimally invasive technique for treating hepatic tumors,necessitating precise monitoring to ensure treatment efficacy and minimize damage to surrounding tissues.This study explores the potential of photoacoustic imaging(PAI)in monitoring MWA by examining ex vivo porcine liver tissues.In this study,a comprehensive analysis of photoacoustic signals was performed to compare the main lobe width(MLW)between ablated and normal regions in porcine liver tissue.Histological staining with succinate dehydrogenase(SDH)and shear wave elastography(SWE)were employed to validate the changes in tissue elasticity after ablation.The analysis demonstrated a notable reduction in the MLW of the average A-lines in ablated tissues compared to nonablated regions(p<0.01).This reduction,attributed to increased tissue density and enhanced elasticity,indicates accelerated sound propagation in thermally ablated areas,which then serves as a critical parameter for mapping tissue characteristics.The reconstruction of the MLW distribution successfully delineated the ablated regions,and was consistent with the results of SDH staining and SWE.In addition,MLW-based imaging exhibited higher spatial resolution compared to SWE.Incorporating MLW analysis into PAI may be a promising strategy to improve the accuracy and effectiveness of MWA monitoring in clinical settings.
文摘Colorectal cancer(CRC)with lung oligometastases,particularly in the presence of extrapulmonary disease,poses considerable therapeutic challenges in clinical practice.We have carefully studied the multicenter study by Hu et al,which evaluated the survival outcomes of patients with metastatic CRC who received image-guided thermal ablation(IGTA).These findings provide valuable clinical evidence supporting IGTA as a feasible,minimally invasive approach and underscore the prognostic significance of metastatic distribution.However,the study by Hu et al has several limitations,including that not all pulmonary lesions were pathologically confirmed,postoperative follow-up mainly relied on dynamic contrast-enhanced computed tomography,no comparative analysis was performed with other local treatments,and the impact of other imaging features on efficacy and prognosis was not evaluated.Future studies should include complete pathological confirmation,integrate functional imaging and radiomics,and use prospective multicenter collaboration to optimize patient selection standards for IGTA treatment,strengthen its clinical evidence base,and ultimately promote individualized decision-making for patients with metastatic CRC.
文摘Over the past ten years,numerous papers have been published on the use of indocyanine green(ICG)fluorescence in liver surgery for hepatocellular carcinoma(HCC).There are many different applications.The first involves targeting superficial tumors in patients with macronodular cirrhosis and an irregular liver surface.In a minimally invasive setting,the lack of tactile feedback on the hepatic surface makes detecting subcapsular HCC with ultrasound alone challenging.ICG fusion images can mimic the tactile feedback of the hand and act as an ultrasound booster.ICG fluorescence can be used to evaluate tumor residues after minimally invasive thermal ablation.ICG fluorescence imaging can also be used to identify the grade of HCC early on and evaluate the microinvasive component.
基金supported by the National Natural Science Foundation of China(Grant Nos.52302115,52231004)。
文摘Hafnium carbide(HfC)serves as a critical ablation-resistant coating for C/C composites used on the wing leading edges of high-speed vehicles during atmospheric re-entry[1-3].Under the action of high-temperature,oxidizing gas flow,the HfC coating forms a high-melting-point heterogeneous oxide layer,significantly delaying oxidation of the underlying material and preserving the structural integrity of the C/C composites[4].
