Brillouin light scattering technique can be successfully used to determine the whole set of elastic and piezoelectric constants of a ZnO single crystal irradiated by different laser energy densities, into a micron ran...Brillouin light scattering technique can be successfully used to determine the whole set of elastic and piezoelectric constants of a ZnO single crystal irradiated by different laser energy densities, into a micron range （radiation layer thickness）. It is found that the scattering intensity, the linewidth and the Brillouin scattering shift of acoustic phonons are all strongly dependent on laser energy density. Based on the sound propagation equations and these results, the directional dependences of the compressional and shear moduli of the irradiated ZnO sample in the （001） plane are investigated. It is found that under an appropriate laser condition, 248 nm KrF excimer laser irradiation can significantly improve the surface quality and increase the elastic properties of ZnO single crystal. This procedure has potential applications in the fabrication of ZnO-based surface acoustic wave and optic-electronic devices.展开更多
The electrocatalytic oxidation of biomass-derived furfural(FF)feedstocks into 2-furoic acid(FA)holds immense industrial potential in optics,cosmetics,polymers,and food.Herein,we fabricated Co O/Ni O/nickel foam(NF)and...The electrocatalytic oxidation of biomass-derived furfural(FF)feedstocks into 2-furoic acid(FA)holds immense industrial potential in optics,cosmetics,polymers,and food.Herein,we fabricated Co O/Ni O/nickel foam(NF)and Cu_(2)O/Ni O/NF electrodes via in situ pulsed laser irradiation in liquids(PLIL)for the bifunctional electrocatalysis of oxygen evolution reaction(OER)and furfural oxidation reaction(FOR),respectively.Simultaneous oxidation of NF surface to NiO and deposition of CoO and/or Cu_(2)O on NF during PLIL offer distinct advantages for enhancing both the OER and FOR.CoO/NiO/NF electrocatalyst provides a consistently low overpotential of~359 m V(OER)at 10 m A/cm^(2),achieving the maximum FA yield(~16.37 m M)with 61.5%selectivity,79.5%carbon balance,and a remarkable Faradaic efficiency of~90.1%during 2 h of FOR at 1.43 V(vs.reversible hydrogen electrode).Mechanistic pathway via in situ electrochemical-Raman spectroscopy on CoO/NiO/NF reveals the involvement of phase transition intermediates(NiOOH and CoOOH)as surface-active centers during electrochemical oxidation.The carbonyl carbon in FF is attacked by hydroxyl groups to form unstable hydrates that subsequently undergo further oxidation to yield FA products.This method holds promise for large-scale applications,enabling simultaneous production of renewable building materials and fuel.展开更多
Because poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS)is water processable,thermally stable,and highly conductive,PEDOT:PSS and its composites have been considered to be one of the most promising f...Because poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS)is water processable,thermally stable,and highly conductive,PEDOT:PSS and its composites have been considered to be one of the most promising flexible thermoelectric materials.However,the PEDOT:PSS film prepared from its commercial aqueous dispersion usually has very low conductivity,thus cannot be directly utilized for TE applications.Here,a simple environmental friendly strategy via femtosecond laser irradiation without any chemical dopants and treatments was demonstrated.Under optimal conditions,the electrical conductivity of the treated film is increased to 803.1 S cm^(-1)from 1.2 S cm^(-1)around three order of magnitude higher,and the power factor is improved to 19.0μW m^(-1)K^(-2),which is enhanced more than 200 times.The mechanism for such remarkable enhancement was attributed to the transition of the PEDOT chains from a coil to a linear or expanded coil conformation,reduction of the interplanar stacking distance,and the removal of insulating PSS with increasing the oxidation level of PEDOT,facilitating the charge transportation.This work presents an effective route for fabricating high-performance flexible conductive polymer films and wearable thermoelectric devices.展开更多
BACKGROUND Lumbar radiculopathy spondylosis is a relatively common orthopedic disease with a high incidence rate.It most commonly occurs in the lumbar 4-5 and lumbar 5-sacral 1 vertebrae,which account for approximatel...BACKGROUND Lumbar radiculopathy spondylosis is a relatively common orthopedic disease with a high incidence rate.It most commonly occurs in the lumbar 4-5 and lumbar 5-sacral 1 vertebrae,which account for approximately 95%of cases.It mostly occurs in people aged 30-50 years old and greatly affects their quality of life.AIM To determine the effect of triple-voltage acupuncture combined with helium-neon laser irradiation on the quality of care and improvement of symptoms in patients with lumbar radiculopathy spondylolisthesis.METHODS In this study,we selected 120 patients with lumbar radiculopathy spondylosis who were treated at our hospital between June 2019 to June 2020.The patients were divided into control and observation groups according to the random number table method,with 60 patients in each group.Patients in the observation group were treated with three-volt moxibustion combined with helium-neon laser irradiation,and those in the control group were treated with lumbar traction.After 1 month of treatment,the lumbar pain scores,lumbar spine motor functions,clinical treatment effects,and nursing satisfaction of the two groups were compared.RESULTS The results showed that acupuncture combined with laser irradiation significantly improved the patients'clinical symptoms,i.e.,reduced their low back pain,significantly lower numerical rating scale pain scores in the observation group than in the control group,and better lumbar spine motility than in the control group,compared to lumbar traction.In addition,they were cared for.The treatment effectiveness rate of the observation group was 95.5%,which was significantly higher than that of the control group(81.67%).Satisfaction with care was higher than 90 points in both groups,but the difference was not statistically significant.CONCLUSION Our study provides a clinical rationale for the future treatment of patients with lumbar spine disease.However,further extensive research is needed for validation.展开更多
We theoretically study the dependence of photoelectron angular distribution on laser polarization direction in nitrogen molecules. The approach is based on the time-dependent density functional theory at the level of ...We theoretically study the dependence of photoelectron angular distribution on laser polarization direction in nitrogen molecules. The approach is based on the time-dependent density functional theory at the level of local density approximation complemented by self-interaction correction. It is found that photoelectron emission in one photon regime could be considered as a probing tool for the main character of different types of molecular orbitals （σ or π）. The pattern of emitted photoelectrons strongly depends on the polarized angle of the laser, for σ orbital, the number of photoelectron decreases with increasing the polarized angle, while for π orbital, it has the inverse relation to the polarized angle, which reveals the multi-electron effect in molecules. On the other hand, concerning the total photoelectron emission, one should take into account a few occupied orbitals instead of only the outmost one.展开更多
An improved indirect scheme for laser positron generation is proposed. The positron yields in high-ZZ metal targets irradiated by laser produced electrons from near-critical density plasmas and underdense plasma are i...An improved indirect scheme for laser positron generation is proposed. The positron yields in high-ZZ metal targets irradiated by laser produced electrons from near-critical density plasmas and underdense plasma are investigated numerically. It is found that the positron yield is mainly affected by the number of electrons of energies up to several hundreds of MeV. Using near-critical density targets for electron acceleration, the number of high energy electrons can be increased dramatically. Through start-to-end simulations, it is shown that up to 6.78×10106.78×1010 positrons can be generated with state-of-the-art Joule-class femtosecond laser systems.展开更多
A study of a nanosecond laser irradiation on the titanium-layer-buried gold planar target is presented. The timeresolved x-ray emission spectra of titanium tracer are measured by a streaked crystal spectrometer. By co...A study of a nanosecond laser irradiation on the titanium-layer-buried gold planar target is presented. The timeresolved x-ray emission spectra of titanium tracer are measured by a streaked crystal spectrometer. By comparing the simulated spectra obtained by using the FLYCHK code with the measured titanium spectra, the temporal plasma states, i.e.,the electron temperatures and densities, are deduced. To evaluate the feasibility of using the method for the characterization of Au plasma states, the deduced plasma states from the measured titanium spectra are compared with the Multi-1D hydrodynamic simulations of laser-produced Au plasmas. By comparing the measured and simulated results, an overall agreement for the electron temperatures is found, whereas there are deviations in the electron densities. The experiment–theory discrepancy may suggest that the plasma state could not be well reproduced by the Multi-1D hydrodynamic simulation, in which the radial gradient is not taken into account. Further investigations on the spectral characterization and hydrodynamic simulations of the plasma states are needed. All the measured and FLYCHK simulated spectra are given in this paper as datasets. The datasets are openly available at http://www.doi.org/10.57760/sciencedb.j00113.00032.展开更多
Seeds of japonica rice (cv. Zhenuo 2) at twodifferent physiological states (dry seeds withwater content 13% and wet seeds soaked inthe water for 36 h) were irradiated by COlaser in four different power-densities. Thes...Seeds of japonica rice (cv. Zhenuo 2) at twodifferent physiological states (dry seeds withwater content 13% and wet seeds soaked inthe water for 36 h) were irradiated by COlaser in four different power-densities. Theseeds irradiated by 200GY ofCo γ rays andno radiated seeds were used as the controls.Results showed that the biological effects展开更多
[ Objective ]The aim of this study was to discuss the feasibility of breeding cabbage with high Vc by 532 nm laser.[ Method ] With the material of cabbage, the embryo of cabbage seeds was irradiated by frequency doubl...[ Objective ]The aim of this study was to discuss the feasibility of breeding cabbage with high Vc by 532 nm laser.[ Method ] With the material of cabbage, the embryo of cabbage seeds was irradiated by frequency doubled Nd ：YAG laser with different power densities and time, and the effects of laser mode on functional leaf area, chlorophyll and Vc contents in cabbage seedlings were also studied. [Result] The results showed that functional leaf area and chlorophyll content were related to laser power density and time when laser power density was 2 -20 mW/mm^2, while the optimal effect was observed at 14 mW/mm^2 for 1 min. The content of Vc in cabbage seedlings was related to dosage of laser irradiation when irradiating time ranged from 1 to 5 min, and the optimal effect was observed at 2.8 J （20 mW/mm^2, 3 min）. [Conclusion] Irradiating the embryo of cabbage seeds with proper irradiation dosage of 532 nm laser can increase its effect on the Vc content significantly.展开更多
The relationship between the yield of thymime-thymine dimer after laser irradiation and physical parameters, such as intensity and pulse number was studied to explore the function of laser irradiation to induce thym...The relationship between the yield of thymime-thymine dimer after laser irradiation and physical parameters, such as intensity and pulse number was studied to explore the function of laser irradiation to induce thymine-thymine dimer. A modified high-performance liquid chromatography (HPLC) method has been developed for the determination of thymine-thymine dimer in DNA for. The thymine-thymine dimer was prepared by a photochemical reaction to be used as the standard substance. The HPLC method we proposed is not interfered by other hydrolysate from DNA. The stability and reproducibility are good, and it can determine as little as 4.42×10 -5 μg·mL -1 thymime-thymine dimer. Three levels of laser intensity to irradiate DNA were selected from calf thymine to test the influence of the pulse number. The mechanism of DNA lesion and repair caused by laser irradiation was studied preliminarily.展开更多
Retaining or improving periodontal ligament （PDL） function is crucial for restoring periodontal defects. The aim of this study was to evaluate the physiological effects of low-power laser irradiation （LPLI） on the...Retaining or improving periodontal ligament （PDL） function is crucial for restoring periodontal defects. The aim of this study was to evaluate the physiological effects of low-power laser irradiation （LPLI） on the proliferation and osteogenic differentiation of human PDL （hPDL） cells. Cultured hPDL cel Is were irradiated （660 nm） daily with doses of O, 1, 2 or 4 J .cm-2. Cell proliferation was evaluated by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide （MTT） assay, and the effect of LPLI on osteogenic differentiation was assessed by Alizarin Red S staining and alkaline phosphatase （ALP） activity. Additionally, osteogenic marker gene expression was confirmed by real-time reverse transcription-polymerase chain reaction （RT-PCR）. Our data showed that LPLI at a dose of 2 J.cm-2 significantly promoted hPDL cell proliferation at days 3 and 5. In addition, LPLI at energy doses of 2 and 4 J.cm-2 showed potential osteogenic capacity, as it stimulated ALP activity, calcium deposition, and osteogenic gene expression. We also showed that cyclic adenosine monophosphate （cAMP） is a critical regulator of the LPLI-mediated effects on hPDL cells. This study shows that LPLI can promote the proliferation and osteogenic differentiation of hPDL cells. These results suggest the potential use of LPLI in clinical applications for periodontal tissue regeneration.展开更多
Oral submucous fibrosis （OSF） is a potentially malignant disorder that is characterized by a progressive fibrosis in the oral submucosa. Arecoline, an alkaloid compound of the areca nut, is reported to be a major ae...Oral submucous fibrosis （OSF） is a potentially malignant disorder that is characterized by a progressive fibrosis in the oral submucosa. Arecoline, an alkaloid compound of the areca nut, is reported to be a major aetiological factor in the development of OSF. Low-power laser irradiation （LPLI） has been reported to be beneficial in fibrosis prevention in different damaged organs. The aim of this study was to investigate the potential therapeutic effects of LPLI on arecoline-induced fibrosis. Arecoline- stimulated human gingival fibroblasts （HGFs） were treated with or without LPLI. The expression levels of the fibrotic marker genes alpha-smooth muscle actin （a-SMA） and connective tissue growth factor （CTGF/CCN2） were analysed by quantitative real- time reverse transcription polymerase chain reaction （RT-PCR） and western blots. In addition, the transcriptional activity of CCN2 was further determined by a reporter assay. The results indicated that arecoline increased the messenger RNA and protein expression of CCN2 and a-SMA in HGF. Interestingly, both LPLI and forskolin, an adenylyl cyclase activator, reduced the expression of arecoline-mediated fibrotic marker genes and inhibited the transcriptional activity of CCN2. Moreover, pretreatment with SQ22536, an adenylyl cyclase inhibitor, blocked LPLI＇s inhibition of the expression of arecoline-mediated fibrotic marker genes. Our data suggest that LPLI may inhibit the expression of arecoline-mediated fibrotic marker genes via the cAMP signalling pathway.展开更多
Stimulated photoluminescence （PL） emission has been observed from an oxide structure of silicon when optically excited by a radiation of 514nm laser. Sharp twin peaks at 694 and 692nm are dominated by stimulated emi...Stimulated photoluminescence （PL） emission has been observed from an oxide structure of silicon when optically excited by a radiation of 514nm laser. Sharp twin peaks at 694 and 692nm are dominated by stimulated emission, which can be demonstrated by its threshold behaviour and linear transition of emission intensity as a function of pump power. The oxide structure is formed by laser irradiation on silicon and its annealing treatment. A model for explaining the stimulated emission is proposed, in which the trap states of the interface between an oxide of silicon and porous nanocrystal play an important role.展开更多
We demonstrate a method of fabricating through micro-holes and micro-hole arrays in silicon using femtosecond laser irradiation and selective chemical etching. The micro-hole formation mechanism is identified as the c...We demonstrate a method of fabricating through micro-holes and micro-hole arrays in silicon using femtosecond laser irradiation and selective chemical etching. The micro-hole formation mechanism is identified as the chemical reaction of the femtosecond laser-induced structure change zone and hydrofluoric acid solution. The morphologies of the through micro-holes and micro-hole arrays are characterized by using scanning electronic microscopy, The effects of the pulse number on the depth and diameter of the holes are investigated. Honeycomb arrays of through micro-holes fabricated at different laser powers and pulse numbers are demonstrated.展开更多
To understand the surface morphology evolution of fused silica induced by 10.6μm CO2 laser irradiation at different parameters, this paper reports that optical microscopy, profilometry, and hydrophilicity tests are u...To understand the surface morphology evolution of fused silica induced by 10.6μm CO2 laser irradiation at different parameters, this paper reports that optical microscopy, profilometry, and hydrophilicity tests are utilized to characterize the surface structure and roughness of the laser irradiated area. The results show that three typical surface morphologies and two typical hydrophilicity test images are observed at different laser powers and pulse durations. The correlations between surface temperature and surface morphology as well as hydrophilicity behaviours are presented. The different hydrophilicity behaviours are related to surface structures of the laser-induced crater and thermal diffusion area. The thermal diffusion length monotonously increases with increasing laser power and pulse duration. The crater width is almost determined by the laser beam size. The crater depth is more sensitive to the laser power and pulse duration than the crater width.展开更多
Oxygen evolution reaction is one of the key processes in the promising renewable energy technique of electrocatalytic water splitting.Developing high ecient oxygen evolution reaction(OER)catalysts requires determinati...Oxygen evolution reaction is one of the key processes in the promising renewable energy technique of electrocatalytic water splitting.Developing high ecient oxygen evolution reaction(OER)catalysts requires determination of the optimal values of the descriptor parameters.Using spinel CoFe2O4 as the model catalyst,this work demonstrates that irradiation with pulsed UV laser can control the quantity of surface oxygen vacancy and thus modify the OER activity,in a volcano-shape evolution trend.This strategy sheds light on quantita-tively investigation of the relationship between surface cation valence,anion vacancy,and physicochemical properties of transition-metal-based compounds.展开更多
The laser irradiation effect on the SERS intensity for Ag film is discussed using crystal violet (CV) as a probe. The thickness of silver film,the etching time of the glass slide by gaseous hydrogen fluoride, and the ...The laser irradiation effect on the SERS intensity for Ag film is discussed using crystal violet (CV) as a probe. The thickness of silver film,the etching time of the glass slide by gaseous hydrogen fluoride, and the laser irradiation time for different amounts of CV on silver films were investigated. The laser burn out model was proposed to explain the dependence of the SERS intensity of CV on the laser irradiation time.展开更多
We predict ultrafast modulation of the pure molten metal surface stress fields under the irradiation of the single femtosecond laser pulse through the two-temperature model molecular-dynamics simulations. High-resolut...We predict ultrafast modulation of the pure molten metal surface stress fields under the irradiation of the single femtosecond laser pulse through the two-temperature model molecular-dynamics simulations. High-resolution and precision calculations are used to resolve the ultrafast laser-induced anisotropic relaxations of the pressure components on the time-scale comparable to the intrinsic liquid density relaxation time. The magnitudes of the dynamic surface tensions are found being modulated sharply within picoseconds after the irradiation, due to the development of the nanometer scale non-hydrostatic regime behind the exterior atomic layer of the liquid surfaces.The reported novel regulation mechanism of the liquid surface stress field and the dynamic surface tension hints at levitating the manipulation of liquid surfaces, such as ultrafast steering the surface directional transport and patterning.展开更多
Systematic experiments about the antitumor effects of low energy laser irradiation combined with the traditional antitumor medicine of cyclophosphamide were conducted using the experimental model of mouse S180 ascite...Systematic experiments about the antitumor effects of low energy laser irradiation combined with the traditional antitumor medicine of cyclophosphamide were conducted using the experimental model of mouse S180 ascites sarcoma.The three groups of tumor bearing mice were irradiated upon the inner corners with the dosages of 11 00,14 67 and 22 00 J·cm -2 LELI respectively,and injected with CYT intraperitoneally to observe the changes of the survival time,the ascites growth speed,and the kinetic changes of immune functions.The survival times of the three groups of CYT/LELI combination were obviously longer than those of the tumor and CYT control groups.Correspondingly,the amounts of ascites,tumor cells densities and total tumor cells in CYT/LELI groups decreased significantly,while the death ratio of the tumor cells increased.Comparatively,the group of 22 00 J·cm -2 LELI combined with CYT showed the most ideal antitumor effects,and the life prolongation ratio was up to 53 20%.展开更多
Different three-dimension （3D） nanotetrapods, containing club-like nanocrystals, nanotetrapods and four-foot-like nanocrystals were synthesized from Zinc sheet via CO2 laser irradiation and coaxially transporting O2...Different three-dimension （3D） nanotetrapods, containing club-like nanocrystals, nanotetrapods and four-foot-like nanocrystals were synthesized from Zinc sheet via CO2 laser irradiation and coaxially transporting O2. Different nanoproducts were fabricated by changing the content of oxygen in the experiment. The morphologies, components, phase structures and optical properties of the products were investigated by a field-emission scanning electron microscopy, an X-ray diffraction, an energy dispersed X-ray spectrometer and a photoluminescence spectroscope. The X-ray diffraction spectra were obtained on a Rigaku D/max 2500PC diffractometer. The experimental results reveal that high quality ZnO nanotetrapods can be fabricated on the special parameters, and growth of ZnO nanotetrapods depends on Vapour-Liquid-Solid（VLS） model, and the content of oxygen in the gas, namely, oxygen partial pressure is one of main factors to control morphologies and optical properties ofZnO nanotetrapods; these advantages above are important for realization of optoelectronic devices.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 10974009)
文摘Brillouin light scattering technique can be successfully used to determine the whole set of elastic and piezoelectric constants of a ZnO single crystal irradiated by different laser energy densities, into a micron range （radiation layer thickness）. It is found that the scattering intensity, the linewidth and the Brillouin scattering shift of acoustic phonons are all strongly dependent on laser energy density. Based on the sound propagation equations and these results, the directional dependences of the compressional and shear moduli of the irradiated ZnO sample in the （001） plane are investigated. It is found that under an appropriate laser condition, 248 nm KrF excimer laser irradiation can significantly improve the surface quality and increase the elastic properties of ZnO single crystal. This procedure has potential applications in the fabrication of ZnO-based surface acoustic wave and optic-electronic devices.
基金supported by the Korea Basic Science Institute(National research Facilities and Equipment Center)grant funded by the Ministry of Education(2019R1A6C1010042,2021R1A6C103A427)the financial support from the National Research Foundation of Korea(NRF)(2022R1A2C2010686,2022R1A4A3033528,2021R1I1A1A01060380,2021R1C1C2010726,2019H1D3A1A01071209)。
文摘The electrocatalytic oxidation of biomass-derived furfural(FF)feedstocks into 2-furoic acid(FA)holds immense industrial potential in optics,cosmetics,polymers,and food.Herein,we fabricated Co O/Ni O/nickel foam(NF)and Cu_(2)O/Ni O/NF electrodes via in situ pulsed laser irradiation in liquids(PLIL)for the bifunctional electrocatalysis of oxygen evolution reaction(OER)and furfural oxidation reaction(FOR),respectively.Simultaneous oxidation of NF surface to NiO and deposition of CoO and/or Cu_(2)O on NF during PLIL offer distinct advantages for enhancing both the OER and FOR.CoO/NiO/NF electrocatalyst provides a consistently low overpotential of~359 m V(OER)at 10 m A/cm^(2),achieving the maximum FA yield(~16.37 m M)with 61.5%selectivity,79.5%carbon balance,and a remarkable Faradaic efficiency of~90.1%during 2 h of FOR at 1.43 V(vs.reversible hydrogen electrode).Mechanistic pathway via in situ electrochemical-Raman spectroscopy on CoO/NiO/NF reveals the involvement of phase transition intermediates(NiOOH and CoOOH)as surface-active centers during electrochemical oxidation.The carbonyl carbon in FF is attacked by hydroxyl groups to form unstable hydrates that subsequently undergo further oxidation to yield FA products.This method holds promise for large-scale applications,enabling simultaneous production of renewable building materials and fuel.
基金supported by the National Key Research and Development Program of China(2020YFA0715000)the Guangdong Basic and Applied Basic Research Foundation(2020A1515110250,2021B1515120041)+1 种基金the Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory(XHT2020-005)the Fundamental Research Funds for the Central Universities(2020IVA068,2021lll007JC)
文摘Because poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS)is water processable,thermally stable,and highly conductive,PEDOT:PSS and its composites have been considered to be one of the most promising flexible thermoelectric materials.However,the PEDOT:PSS film prepared from its commercial aqueous dispersion usually has very low conductivity,thus cannot be directly utilized for TE applications.Here,a simple environmental friendly strategy via femtosecond laser irradiation without any chemical dopants and treatments was demonstrated.Under optimal conditions,the electrical conductivity of the treated film is increased to 803.1 S cm^(-1)from 1.2 S cm^(-1)around three order of magnitude higher,and the power factor is improved to 19.0μW m^(-1)K^(-2),which is enhanced more than 200 times.The mechanism for such remarkable enhancement was attributed to the transition of the PEDOT chains from a coil to a linear or expanded coil conformation,reduction of the interplanar stacking distance,and the removal of insulating PSS with increasing the oxidation level of PEDOT,facilitating the charge transportation.This work presents an effective route for fabricating high-performance flexible conductive polymer films and wearable thermoelectric devices.
文摘BACKGROUND Lumbar radiculopathy spondylosis is a relatively common orthopedic disease with a high incidence rate.It most commonly occurs in the lumbar 4-5 and lumbar 5-sacral 1 vertebrae,which account for approximately 95%of cases.It mostly occurs in people aged 30-50 years old and greatly affects their quality of life.AIM To determine the effect of triple-voltage acupuncture combined with helium-neon laser irradiation on the quality of care and improvement of symptoms in patients with lumbar radiculopathy spondylolisthesis.METHODS In this study,we selected 120 patients with lumbar radiculopathy spondylosis who were treated at our hospital between June 2019 to June 2020.The patients were divided into control and observation groups according to the random number table method,with 60 patients in each group.Patients in the observation group were treated with three-volt moxibustion combined with helium-neon laser irradiation,and those in the control group were treated with lumbar traction.After 1 month of treatment,the lumbar pain scores,lumbar spine motor functions,clinical treatment effects,and nursing satisfaction of the two groups were compared.RESULTS The results showed that acupuncture combined with laser irradiation significantly improved the patients'clinical symptoms,i.e.,reduced their low back pain,significantly lower numerical rating scale pain scores in the observation group than in the control group,and better lumbar spine motility than in the control group,compared to lumbar traction.In addition,they were cared for.The treatment effectiveness rate of the observation group was 95.5%,which was significantly higher than that of the control group(81.67%).Satisfaction with care was higher than 90 points in both groups,but the difference was not statistically significant.CONCLUSION Our study provides a clinical rationale for the future treatment of patients with lumbar spine disease.However,further extensive research is needed for validation.
文摘We theoretically study the dependence of photoelectron angular distribution on laser polarization direction in nitrogen molecules. The approach is based on the time-dependent density functional theory at the level of local density approximation complemented by self-interaction correction. It is found that photoelectron emission in one photon regime could be considered as a probing tool for the main character of different types of molecular orbitals （σ or π）. The pattern of emitted photoelectrons strongly depends on the polarized angle of the laser, for σ orbital, the number of photoelectron decreases with increasing the polarized angle, while for π orbital, it has the inverse relation to the polarized angle, which reveals the multi-electron effect in molecules. On the other hand, concerning the total photoelectron emission, one should take into account a few occupied orbitals instead of only the outmost one.
基金Supported by the National Basic Research Program of China under Grant No 2013CBA01502the National Natural Science Foundation of China under Grant Nos 11575011 and 11535001+1 种基金the National Grand Instrument Project under Grant No2012YQ030142the UK EPSRC under Grant Nos EP/G054950/1,EP/G056803/1,EP/G055165/1 and EP/M022463/1
文摘An improved indirect scheme for laser positron generation is proposed. The positron yields in high-ZZ metal targets irradiated by laser produced electrons from near-critical density plasmas and underdense plasma are investigated numerically. It is found that the positron yield is mainly affected by the number of electrons of energies up to several hundreds of MeV. Using near-critical density targets for electron acceleration, the number of high energy electrons can be increased dramatically. Through start-to-end simulations, it is shown that up to 6.78×10106.78×1010 positrons can be generated with state-of-the-art Joule-class femtosecond laser systems.
基金Project supported by the National Key Research and Development Program of China (Grant No.2017YFA0403300)the National Natural Science Foundation of China (Grant Nos.12074352 and 11675158)Fundamental Research Funds for the Central Universities in China (Grant No.YJ202144)。
文摘A study of a nanosecond laser irradiation on the titanium-layer-buried gold planar target is presented. The timeresolved x-ray emission spectra of titanium tracer are measured by a streaked crystal spectrometer. By comparing the simulated spectra obtained by using the FLYCHK code with the measured titanium spectra, the temporal plasma states, i.e.,the electron temperatures and densities, are deduced. To evaluate the feasibility of using the method for the characterization of Au plasma states, the deduced plasma states from the measured titanium spectra are compared with the Multi-1D hydrodynamic simulations of laser-produced Au plasmas. By comparing the measured and simulated results, an overall agreement for the electron temperatures is found, whereas there are deviations in the electron densities. The experiment–theory discrepancy may suggest that the plasma state could not be well reproduced by the Multi-1D hydrodynamic simulation, in which the radial gradient is not taken into account. Further investigations on the spectral characterization and hydrodynamic simulations of the plasma states are needed. All the measured and FLYCHK simulated spectra are given in this paper as datasets. The datasets are openly available at http://www.doi.org/10.57760/sciencedb.j00113.00032.
文摘Seeds of japonica rice (cv. Zhenuo 2) at twodifferent physiological states (dry seeds withwater content 13% and wet seeds soaked inthe water for 36 h) were irradiated by COlaser in four different power-densities. Theseeds irradiated by 200GY ofCo γ rays andno radiated seeds were used as the controls.Results showed that the biological effects
基金Supported by Fund from Jilin Provincial Science & Technology Department(20090541)Project from Department of Education ofJilin Province(200828)~~
文摘[ Objective ]The aim of this study was to discuss the feasibility of breeding cabbage with high Vc by 532 nm laser.[ Method ] With the material of cabbage, the embryo of cabbage seeds was irradiated by frequency doubled Nd ：YAG laser with different power densities and time, and the effects of laser mode on functional leaf area, chlorophyll and Vc contents in cabbage seedlings were also studied. [Result] The results showed that functional leaf area and chlorophyll content were related to laser power density and time when laser power density was 2 -20 mW/mm^2, while the optimal effect was observed at 14 mW/mm^2 for 1 min. The content of Vc in cabbage seedlings was related to dosage of laser irradiation when irradiating time ranged from 1 to 5 min, and the optimal effect was observed at 2.8 J （20 mW/mm^2, 3 min）. [Conclusion] Irradiating the embryo of cabbage seeds with proper irradiation dosage of 532 nm laser can increase its effect on the Vc content significantly.
文摘The relationship between the yield of thymime-thymine dimer after laser irradiation and physical parameters, such as intensity and pulse number was studied to explore the function of laser irradiation to induce thymine-thymine dimer. A modified high-performance liquid chromatography (HPLC) method has been developed for the determination of thymine-thymine dimer in DNA for. The thymine-thymine dimer was prepared by a photochemical reaction to be used as the standard substance. The HPLC method we proposed is not interfered by other hydrolysate from DNA. The stability and reproducibility are good, and it can determine as little as 4.42×10 -5 μg·mL -1 thymime-thymine dimer. Three levels of laser intensity to irradiate DNA were selected from calf thymine to test the influence of the pulse number. The mechanism of DNA lesion and repair caused by laser irradiation was studied preliminarily.
基金supported by grants from the Kaohsiung Medical University of Taiwan (KMU-Q099018 and KMU-Q098025)
文摘Retaining or improving periodontal ligament （PDL） function is crucial for restoring periodontal defects. The aim of this study was to evaluate the physiological effects of low-power laser irradiation （LPLI） on the proliferation and osteogenic differentiation of human PDL （hPDL） cells. Cultured hPDL cel Is were irradiated （660 nm） daily with doses of O, 1, 2 or 4 J .cm-2. Cell proliferation was evaluated by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide （MTT） assay, and the effect of LPLI on osteogenic differentiation was assessed by Alizarin Red S staining and alkaline phosphatase （ALP） activity. Additionally, osteogenic marker gene expression was confirmed by real-time reverse transcription-polymerase chain reaction （RT-PCR）. Our data showed that LPLI at a dose of 2 J.cm-2 significantly promoted hPDL cell proliferation at days 3 and 5. In addition, LPLI at energy doses of 2 and 4 J.cm-2 showed potential osteogenic capacity, as it stimulated ALP activity, calcium deposition, and osteogenic gene expression. We also showed that cyclic adenosine monophosphate （cAMP） is a critical regulator of the LPLI-mediated effects on hPDL cells. This study shows that LPLI can promote the proliferation and osteogenic differentiation of hPDL cells. These results suggest the potential use of LPLI in clinical applications for periodontal tissue regeneration.
基金supported by the Kaohsiung Municipal Ta-Tung Hospital(grant kmtth-102-010)the Kaohsiung Medical University in Taiwan under the grant“Aim for the Top Universities Grant”(KMU-TP103B08)
文摘Oral submucous fibrosis （OSF） is a potentially malignant disorder that is characterized by a progressive fibrosis in the oral submucosa. Arecoline, an alkaloid compound of the areca nut, is reported to be a major aetiological factor in the development of OSF. Low-power laser irradiation （LPLI） has been reported to be beneficial in fibrosis prevention in different damaged organs. The aim of this study was to investigate the potential therapeutic effects of LPLI on arecoline-induced fibrosis. Arecoline- stimulated human gingival fibroblasts （HGFs） were treated with or without LPLI. The expression levels of the fibrotic marker genes alpha-smooth muscle actin （a-SMA） and connective tissue growth factor （CTGF/CCN2） were analysed by quantitative real- time reverse transcription polymerase chain reaction （RT-PCR） and western blots. In addition, the transcriptional activity of CCN2 was further determined by a reporter assay. The results indicated that arecoline increased the messenger RNA and protein expression of CCN2 and a-SMA in HGF. Interestingly, both LPLI and forskolin, an adenylyl cyclase activator, reduced the expression of arecoline-mediated fibrotic marker genes and inhibited the transcriptional activity of CCN2. Moreover, pretreatment with SQ22536, an adenylyl cyclase inhibitor, blocked LPLI＇s inhibition of the expression of arecoline-mediated fibrotic marker genes. Our data suggest that LPLI may inhibit the expression of arecoline-mediated fibrotic marker genes via the cAMP signalling pathway.
基金supported by the National Natural Science Foundation of China (Grant No 10764002)
文摘Stimulated photoluminescence （PL） emission has been observed from an oxide structure of silicon when optically excited by a radiation of 514nm laser. Sharp twin peaks at 694 and 692nm are dominated by stimulated emission, which can be demonstrated by its threshold behaviour and linear transition of emission intensity as a function of pump power. The oxide structure is formed by laser irradiation on silicon and its annealing treatment. A model for explaining the stimulated emission is proposed, in which the trap states of the interface between an oxide of silicon and porous nanocrystal play an important role.
基金Supported by the National Basic Research Program of China under Grant No 2012CB921804the National Natural Science Foundation of China under Grant Nos 11204236 and 61308006the Collaborative Innovation Center of Suzhou Nano Science and Technology
文摘We demonstrate a method of fabricating through micro-holes and micro-hole arrays in silicon using femtosecond laser irradiation and selective chemical etching. The micro-hole formation mechanism is identified as the chemical reaction of the femtosecond laser-induced structure change zone and hydrofluoric acid solution. The morphologies of the through micro-holes and micro-hole arrays are characterized by using scanning electronic microscopy, The effects of the pulse number on the depth and diameter of the holes are investigated. Honeycomb arrays of through micro-holes fabricated at different laser powers and pulse numbers are demonstrated.
基金supported by the National High Technology Research and Development Program of China (Grant No. 2008AA8040508)the Foundation for Young Scholars of University of Electronic Science and Technology of China (Grant No. L08010401JX0806)
文摘To understand the surface morphology evolution of fused silica induced by 10.6μm CO2 laser irradiation at different parameters, this paper reports that optical microscopy, profilometry, and hydrophilicity tests are utilized to characterize the surface structure and roughness of the laser irradiated area. The results show that three typical surface morphologies and two typical hydrophilicity test images are observed at different laser powers and pulse durations. The correlations between surface temperature and surface morphology as well as hydrophilicity behaviours are presented. The different hydrophilicity behaviours are related to surface structures of the laser-induced crater and thermal diffusion area. The thermal diffusion length monotonously increases with increasing laser power and pulse duration. The crater width is almost determined by the laser beam size. The crater depth is more sensitive to the laser power and pulse duration than the crater width.
基金supported by the National Key Basic Research Program of China (2016YFA0300102)the National Natural Science Foundation of China (No.11675179,No.U1532142,and No.11434009)the Fundamental Research Funds for the Central Universities
文摘Oxygen evolution reaction is one of the key processes in the promising renewable energy technique of electrocatalytic water splitting.Developing high ecient oxygen evolution reaction(OER)catalysts requires determination of the optimal values of the descriptor parameters.Using spinel CoFe2O4 as the model catalyst,this work demonstrates that irradiation with pulsed UV laser can control the quantity of surface oxygen vacancy and thus modify the OER activity,in a volcano-shape evolution trend.This strategy sheds light on quantita-tively investigation of the relationship between surface cation valence,anion vacancy,and physicochemical properties of transition-metal-based compounds.
文摘The laser irradiation effect on the SERS intensity for Ag film is discussed using crystal violet (CV) as a probe. The thickness of silver film,the etching time of the glass slide by gaseous hydrogen fluoride, and the laser irradiation time for different amounts of CV on silver films were investigated. The laser burn out model was proposed to explain the dependence of the SERS intensity of CV on the laser irradiation time.
基金the National Key R&D Program of China (Grant No. 2019YFA0705000)the National Natural Science Foundation of China (Grant Nos. 11874147, 11933005, and 12134001)+3 种基金the Science and Technology Commission of Shanghai Municipality (Grant No. 21DZ1101500)the Shanghai Municipal Science and Technology Major Project (Grant No. 2019SHZDZX01)the Natural Science Foundation of Chongqing, China (Grant No. cstc2021jcyj-msxm X1144)the State Key Laboratory of Solidification Processing in NWPU (Grant No. SKLSP202105)。
文摘We predict ultrafast modulation of the pure molten metal surface stress fields under the irradiation of the single femtosecond laser pulse through the two-temperature model molecular-dynamics simulations. High-resolution and precision calculations are used to resolve the ultrafast laser-induced anisotropic relaxations of the pressure components on the time-scale comparable to the intrinsic liquid density relaxation time. The magnitudes of the dynamic surface tensions are found being modulated sharply within picoseconds after the irradiation, due to the development of the nanometer scale non-hydrostatic regime behind the exterior atomic layer of the liquid surfaces.The reported novel regulation mechanism of the liquid surface stress field and the dynamic surface tension hints at levitating the manipulation of liquid surfaces, such as ultrafast steering the surface directional transport and patterning.
文摘Systematic experiments about the antitumor effects of low energy laser irradiation combined with the traditional antitumor medicine of cyclophosphamide were conducted using the experimental model of mouse S180 ascites sarcoma.The three groups of tumor bearing mice were irradiated upon the inner corners with the dosages of 11 00,14 67 and 22 00 J·cm -2 LELI respectively,and injected with CYT intraperitoneally to observe the changes of the survival time,the ascites growth speed,and the kinetic changes of immune functions.The survival times of the three groups of CYT/LELI combination were obviously longer than those of the tumor and CYT control groups.Correspondingly,the amounts of ascites,tumor cells densities and total tumor cells in CYT/LELI groups decreased significantly,while the death ratio of the tumor cells increased.Comparatively,the group of 22 00 J·cm -2 LELI combined with CYT showed the most ideal antitumor effects,and the life prolongation ratio was up to 53 20%.
基金Funded by the Open Foundation of Jiangsu Provincial Key Laboratory of Photon-manufacture (GZ200708)the 7th Student Research Train Programof Jiangsu University (No. 07A172)
文摘Different three-dimension （3D） nanotetrapods, containing club-like nanocrystals, nanotetrapods and four-foot-like nanocrystals were synthesized from Zinc sheet via CO2 laser irradiation and coaxially transporting O2. Different nanoproducts were fabricated by changing the content of oxygen in the experiment. The morphologies, components, phase structures and optical properties of the products were investigated by a field-emission scanning electron microscopy, an X-ray diffraction, an energy dispersed X-ray spectrometer and a photoluminescence spectroscope. The X-ray diffraction spectra were obtained on a Rigaku D/max 2500PC diffractometer. The experimental results reveal that high quality ZnO nanotetrapods can be fabricated on the special parameters, and growth of ZnO nanotetrapods depends on Vapour-Liquid-Solid（VLS） model, and the content of oxygen in the gas, namely, oxygen partial pressure is one of main factors to control morphologies and optical properties ofZnO nanotetrapods; these advantages above are important for realization of optoelectronic devices.
