Low-level laser therapy(LLLT) may have an effect on the pain associated with orthodontic treatment. The aim of this study was to evaluate the effect of LLLT on pain and somatosensory sensitization induced by orthodont...Low-level laser therapy(LLLT) may have an effect on the pain associated with orthodontic treatment. The aim of this study was to evaluate the effect of LLLT on pain and somatosensory sensitization induced by orthodontic treatment. Forty individuals(12–33 years old; mean ± standard deviations: 20.8 ± 5.9 years) scheduled to receive orthodontic treatment were randomly divided into a laser group(LG) or a placebo group(PG)(1:1). The LG received LLLT(810-nm gallium-aluminium-arsenic diode laser in continuous mode with the power set at 400 mW, 2 J·cm–2) at 0 h, 2 h, 24 h, 4 d, and 7 d after treatment, and the PG received inactive treatment at the same time points. In both groups, the non-treated side served as a control. A numerical rating scale(NRS) of pain, pressure pain thresholds(PPTs), cold detection thresholds(CDTs), warmth detection thresholds(WDTs), cold pain thresholds(CPTs), and heat pain thresholds(HPTs) were tested on both sides at the gingiva and canine tooth and on the hand. The data were analysed by a repeated measures analysis of variance(ANOVA). The NRS pain scores were significantly lower in the LG group(P = 0.01). The CDTs,CPTs, WDTs, HPTs, and PPTs at the gingiva and the PPTs at the canine tooth were significantly less sensitive on the treatment side of the LG compared with that of the PG(P < 0.033). The parameters tested also showed significantly less sensitivity on the nontreatment side of the LG compared to that of the PG(P < 0.043). There were no differences between the groups for any quantitative sensory testing(QST) measures of the hand. The application of LLLT appears to reduce the pain and sensitivity of the tooth and gingiva associated with orthodontic treatment and may have contralateral effects within the trigeminal system but no generalized QST effects. Thus, the present study indicated a significant analgesia effect of LLLT application during orthodontic treatment.Further clinical applications are suggested.展开更多
Background: Patients commonly develop postoperative pain after total knee arthroplasty(TKA).Acupuncture-related techniques and low-level laser therapy could be beneficial for pain management for older individuals.Obje...Background: Patients commonly develop postoperative pain after total knee arthroplasty(TKA).Acupuncture-related techniques and low-level laser therapy could be beneficial for pain management for older individuals.Objective: To examine the effect of low-level laser acupuncture(LA) in reducing postoperative pain, painrelated interference in daily life, morphine consumption, and morphine-related side effects in older patients with knee osteoarthritis who underwent TKA.Design, setting, participants and intervention: A single-blind randomized placebo-controlled trial was conducted. Patients(N = 82) were recruited and randomly assigned via a computer-generated list to the LA group or a placebo group. The LA group received low-level laser therapy at Sanyinjiao(SP6), Taixi(KI3),Kunlun(BL60), Fengshi(GB31), Futu(ST32) and Neiguan(PC6) after TKA, while the placebo acupuncture group received the same treatment procedure without laser energy output.Main outcome measures: The primary outcome was postoperative pain intensity, and it was measured at baseline and hours 2, 6, 10, 24, 48 and 72 after TKA. The secondary outcomes, including relative pain,postoperative pain-related interference in daily life and morphine consumption, were measured at hours24, 48 and 72 after TKA.Results: Generalized estimating equations revealed significant between-group differences in pain intensity(P = 0.01), and trend differences in pain intensity for the LA group starting at hours 10 to 72(P < 0.05)and morphine consumption at hours 48 and 72(P < 0.05). The changes in pain-related interference in daily life were significant(P < 0.05) at 72 h, with the exception of the parameters for worst pain, mood,and sleep. Nausea and vomiting side effects from morphine had significant between-group differences at hours 10 and 24(P < 0.05).Conclusion: Low-level LA gradually reduced older patients’ postoperative pain intensity and morphine consumption within the first 72 h after their TKA for osteoarthritis. Low-level LA may have benefits as an adjuvant pain management technique for clinical care.Trial registration: ClinicalTrials.gov registration number NCT03995446.展开更多
Background : Osteoporosis can make bone repair difficult. Low-level laser therapy( LLLT) has been shown to be a promising tool for bone neoformation. This study aimed to analyze the effect of LLLT on calvaria bone def...Background : Osteoporosis can make bone repair difficult. Low-level laser therapy( LLLT) has been shown to be a promising tool for bone neoformation. This study aimed to analyze the effect of LLLT on calvaria bone defects of ovariectomized rats using stereology. Methods : Fifty-four Wistar rats were subjected to bilateral ovariectomy, and bone defects were created in calvaria after 150 days. The animals were divided into nine groups(n = ?6 per group), and 24 hours after the bone defects were created they received three, six or 12 sessions of LLLT at 0, 20 or 30 J/cm 2, using a 780-nm low-intensity GaAlAs laser. One-way ANOVA followed by Tukey ' s post hoc test was used for data processing. A difference of P < 0.05 was considered statistically significant. The parameters evaluated were osteocyte density( Nv_(ost)), total osteocyte number( Nto ost), trabecular surface density( Sv_t), and trabecular surface area( Sa_t). Results : Data obtained showed that Nto ost, Sv t, and Sa t in group G2 rats were significantly different from G1(0 J/cm^2)( P < 0.05). Compared to group G4, G5 presented higher values for the parameters Sv t and Sa t, and G6 presented significantly higher values for almost all the analyzed parameters( Nv _(ost), Nto_(ost), Sv_t, and Sa t)( P < 0.05). Compared to group G7, G8 showed a higher value only for the parameter Sa t, and G9 showed significantly higher values for parameters Nv ost, Nto ost, Sv_t, and Sa_t. Conclusion : We conclude that LLLT stimulated bone neoformation and contributed to an increase in the total number of osteocytes, especially with a laser energy density of 30 J/cm^2 given for six and 12 sessions.展开更多
Peripheral nerve injuries are common in clinical practice because of traumas such as crushing and sectioning. Lesions of the nerve structure result in lost or diminished sensitivity and/or motor activity in the innerv...Peripheral nerve injuries are common in clinical practice because of traumas such as crushing and sectioning. Lesions of the nerve structure result in lost or diminished sensitivity and/or motor activity in the innervated territory. The degree of lesion depends on the specific nerve involved, the magnitude and type of pres- sure exerted, and the duration of the compression. The results of such injuries commonly include axonal degeneration and retro- grade degeneration of the corresponding neurons in the spinal medulla, followed by very slow regeneration （Rochkind et al., 2001）. The adverse effects on the daily activities of patients with a peripheral nerve injury are a determining factor in establishing the goals of early recovery （Rodriguez et al., 2004）.展开更多
Objective:To investigate the effect of Kangfuxin Solution(康复新液)combined with low-level laser therapy(LLLT)on cytokines and immune function in patients with radiation-induced oral mucositis.Methods:There were 84 na...Objective:To investigate the effect of Kangfuxin Solution(康复新液)combined with low-level laser therapy(LLLT)on cytokines and immune function in patients with radiation-induced oral mucositis.Methods:There were 84 nasopharyngeal carcinoma patients with oral mucositis after intensity-modulated radiation therapy(IMRT)were randomly divided into the control group(CG)and the observation group(OG),with 42 cases in each group.The CG was given LLLT,and the OG was treated with Kangfuxin Solution in addition to LLLT for 10 consecutive days.The healing time of oral mucosa,mucositis grading,oral pain scores,cytokines(interleukin-6,interleukin-1βand tumor necrosis factor-α)and T lymphocyte subsets were compared between the 2 groups before and after treatment.Results:The healing time of oral mucosa in the OG was(6.8±1.4)d,which was significantly shorter than(8.6±1.9)d in the CG(t=4.943,P<0.01).After treatment,the grading of oral mucositis in the OG was better than that in the CG,with a statistically significant difference(Z=2.942,P<0.05).The oral pain scores of the OG was lower than that in the CG at different time points after treatment,and the difference was statistically significant(t=8.207,11.017,P<0.01).After treatment,the levels of IL-6,IL-1βand TNF-αin peripheral blood of the OG were significantly lower than those in the CG(t=5.217,2.775,4.053,P<0.01).There were statistically significant differences in CD4+,CD8+and CD4+/CD8+between the OG and the CG after treatment(t=5.692,6.093,3.658,P<0.01).Conclusion:Kangfuxin Solution combined with LLLT can significantly shorten the healing time of oral mucosal,reduce the grading of oral mucositis,relieve oral pain,reduce inflammatory response and improve the immune function of patients.展开更多
Low-level laser therapy (LLLT) or cold laser has been used in medicine for several decades. However, the method utilizes a direct contact of the light beam with a patient. Further research resulted in development of a...Low-level laser therapy (LLLT) or cold laser has been used in medicine for several decades. However, the method utilizes a direct contact of the light beam with a patient. Further research resulted in development of another method that enables remote transmission of the pharmacological properties of a medicament into a human body with the application of low-level laser radiation as the light source. 18 patients with different viral diseases were treated with the antiviral drugs placed into the field formed by the unexplained properties of low-level laser radiation of the “device for transfer of the pharmacological properties of a drug into the patient’s body”. This resulted in improvement of the patient’s condition, the absence of side effects and adverse reactions when using drugs in the proposed device and shortened therapy period for patients with chronic hepatitis C infection and Covid-19 patients. The long-term follow-up of the patients with chronic hepatitis B infection showed that hepatitis B virus remained at low replication levels under the influence of the therapy, which made it possible to avoid such formidable complications of the disease as cirrhosis of the liver and liver cancer.展开更多
Acute renal failure has a 50% - 80% mortality rate. Currently, treatment options for this life-threatening disease are limited. Low-level laser therapy (LLLT) has been found to modulate biological activity. The aim of...Acute renal failure has a 50% - 80% mortality rate. Currently, treatment options for this life-threatening disease are limited. Low-level laser therapy (LLLT) has been found to modulate biological activity. The aim of the present study was to investigate the possible beneficial effects of laser application to stem cells in the bone marrow, on the kidneys of rats that had undergone ischemia-reperfusion injury (IRI). IRI was induced by occlusion of the renal artery to 3- and 7-month-old rats for 15 or 30 minutes. In an additional experiment IRI was applied to both kidneys for 20 min each in 2-3-month-old rats. Rats were then divided randomly into two groups of control and laser-treated. Laser therapy (Ga-Al-As 810 nm, 200 mW output for 2 min) was applied to the bone marrow 1 and 7 days post-IRI to the kidneys, and rats were sacrificed 2 weeks later. Histomorphometry and immunohistochemistry were performed on kidney sections and blood markers for kidney function. Quantitative histomorphometric analysis revealed a reduction in dilatation of the renal tubules, restored structural integrity of the renal tubules, and reduced necrosis in the laser-treated rats as compared to the control, non-laser-irradiated group. C-kit positive cell density in kidneys post-IRI and laser-treatment was significantly (p = 0.015) 3.2-fold higher compared to the control group. Creatinine and blood urea nitrogen content were significantly lower in the laser-treated rats as compared to control. It is concluded that LLLT application to the bone marrow (BM) causes a significant increase in the density of mesenchymal stem cells in the kidneys post-IRI, probably by induction of stem cells in the BM, which subsequently migrate to the IRI kidney, significantly reducing the pathological features of the kidney and increasing kidney function post IRI.展开更多
Objective: The aim of the study is to evaluate the effect of low-level laser therapy in comparison to compression bandage therapy in the treatment of venous ulcers. Subjects & Methods: This study was carried out i...Objective: The aim of the study is to evaluate the effect of low-level laser therapy in comparison to compression bandage therapy in the treatment of venous ulcers. Subjects & Methods: This study was carried out in the period from March 2013 to March 2014. The study included 40 adult patients with a diagnosis of venous ulcer classified as C6 according to the clinical classification of CEAP classification. The patients were divided into 2 groups: the first one included 20 patients treated by low-level laser therapy at the Rheumatology and Rehabilitation department, and the second group included 20 patients in whom we use four layers compression bandaging at the vascular surgery department. Results: 32 ulcers were treated in group I and 35 ulcers were treated in group II. The patients of group I were 7 (35%) females and 13 (65%) males, their age range were (24 - 56) years. The patients of group II were 11 (55%) males and 9 (45%) females;their age ranges were (32 - 50) years. Measurements of the ulcers size by (cm2) were taken at the beginning of therapy, at 1 month, at 2 months and at 3 months later on. The calculation of the area of the ulcer was done by using the graph papers to document the ulcer’s perpendicular linear dimensions. According to the size of the ulcer, some ulcers heal within 1 month (15.6%) ulcers in group I, and (28.5%) in group II. Some ulcers heal within 2 months (28%) in group I, and (37%) in group II. The remaining ulcers heal within 3 months or more which are (56%) ulcers in group I, and (34.2%) ulcers in group II. The recurrence rate of chronic venous leg ulcer in compression bandage technique used in group II was the least one as the total number of recurrent cases were 5 (25%), followed by laser therapy used in group I. Conclusion: There was no significant efficacy of the low-level laser therapy over the four layers compression technique in the management of chronic venous ulcers.展开更多
Nitric oxide(NO)and nitric oxide synthase(NOS)have an important role in pain signaling transmission in animal models.Low-level laser therapy(LLLT)is known to have an analgesic effect,but the mechanism is unclear.The a...Nitric oxide(NO)and nitric oxide synthase(NOS)have an important role in pain signaling transmission in animal models.Low-level laser therapy(LLLT)is known to have an analgesic effect,but the mechanism is unclear.The aim of the study is to investigate the influence of LLLT on NO release and NOS synthesis in dorsal root ganglion(DRG)neurons,in order to find whether LLLI can ameliorate pain through modulating NO production at the cellular level.The results show that in stress conditions,the laser irradiation at 658 nm can modulate NO production in DRG neurons with soma diameter of about 20μm in a short time after illumination,and affect NOS synthesis in a dose-dependent manner.It is demonstrated that LLLT might treat pain by altering NO release directly and indirectly in DRG neurons.展开更多
Objective: To study the effect of low-level laser irradiation (LLLI) combined with ferulic acid on the osteoblast differentiation and maturation as well as osteogenesis signaling pathway expression. Methods: The crani...Objective: To study the effect of low-level laser irradiation (LLLI) combined with ferulic acid on the osteoblast differentiation and maturation as well as osteogenesis signaling pathway expression. Methods: The cranium was collected from the SD rats born within 24 h, osteoblasts were separated, cultured and then divided into control group, ferulic acid group, LLLI group, ferulic acid + LLLI group, and the expression osteoblast differentiation markers, proliferation molecules and signaling pathway molecules were detected after continuous treatment with different conditions for three days. Results: 3 d after treatment, the Bax and Bid mRNA expression in ferulic acid group, LLLI group and ferulic acid + LLLI group of cells were significantly lower than those in control group while Bcl-2, CyclinD1, E2F, Col-I, OC and ALP mRNA expression as well as Wnt, β-catenin, Runx2, cAMP and PKA protein expression were significantly higher than those in control group;Bax and Bid mRNA expression in ferulic acid + LLLI group of cells were significantly lower than those in ferulic acid group and LLLI group while Bcl-2, CyclinD1, E2F, Col-I, OC and ALP mRNA expression as well as Wnt, β-catenin, Runx2, cAMP and PKA protein expression were significantly higher than those in ferulic acid group and LLLI group;Col-I, OC, ALP, Bax, Bid, Bcl-2, CyclinD1 and E2F mRNA expression as well as Wnt, β-catenin, Runx2, cAMP and PKA protein expression were not significantly different between ferulic acid group and LLLI group. Conclusion: Low-level laser irradiation (LLLI) combined with ferulic acid can promote osteoblast differentiation and maturation and activate osteogenesis signaling pathway.展开更多
Low-level laser therapy(LLLT)has been clinically utilized for many indications in medicine requiring protection from el/issue death,stimulation of healing and repair of injuries,pain reduction,swelling and inflammatio...Low-level laser therapy(LLLT)has been clinically utilized for many indications in medicine requiring protection from el/issue death,stimulation of healing and repair of injuries,pain reduction,swelling and inflammation.Presently,the use of LLLT to treat stroke,traumnatic brain injury and cognitive dysfunction are attracting growing interest.Near infrared light is capable of penetrating into the cerebral cortex,allowing noninvasive treatments to be caried out with few treatment-related adverse events.Optimization of LLLT treatment flfect is a crucial isse of this field;however,only a few experimental tests on mice for wavelength selection have been reported.We addressed this ssue by low-ost,straightforward and quantitative comparisons on light dosage distribution within visible Chinese human head by Monte Carlo modeling of near infrared light propagation.Optimized selection in wavelength,beam type and size were given based on comparisons among frequently used setups(ie,wavelengths:660,810 and 980 nm;beam type:Gaussian and flat beamn;beam diameter:2,4 and 6 cm).This study provided an fficient way for guiding the optimization of LLLT setup and selection on wavelength,beam type and size for clinical brain LLLT.展开更多
A dual-phase synergistic enhancement method was adopted to strengthen the Al-Mn-Mg-Sc-Zr alloy fabricated by laser powder bed fusion(LPBF)by leveraging the unique advantages of Er and TiB_(2).Spherical powders of 0.5w...A dual-phase synergistic enhancement method was adopted to strengthen the Al-Mn-Mg-Sc-Zr alloy fabricated by laser powder bed fusion(LPBF)by leveraging the unique advantages of Er and TiB_(2).Spherical powders of 0.5wt%Er-1wt%TiB_(2)/Al-Mn-Mg-Sc-Zr nanocomposite were prepared using vacuum homogenization technique,and the density of samples prepared through the LPBF process reached 99.8%.The strengthening and toughening mechanisms of Er-TiB_(2)were investigated.The results show that Al_(3)Er diffraction peaks are detected by X-ray diffraction analysis,and texture strength decreases according to electron backscatter diffraction results.The added Er and TiB_(2)nano-reinforcing phases act as heterogeneous nucleation sites during the LPBF forming process,hindering grain growth and effectively refining the grains.After incorporating the Er-TiB_(2)dual-phase nano-reinforcing phases,the tensile strength and elongation at break of the LPBF-deposited samples reach 550 MPa and 18.7%,which are 13.4%and 26.4%higher than those of the matrix material,respectively.展开更多
To explore the formation mechanism of anisotropy in Ti-6Al-4V alloy fabricated by selective laser melting(SLM),the compressive mechanical properties,microhardness,microstructure,and crystallographic orientation of the...To explore the formation mechanism of anisotropy in Ti-6Al-4V alloy fabricated by selective laser melting(SLM),the compressive mechanical properties,microhardness,microstructure,and crystallographic orientation of the alloy across different planes were investigated.The anisotropy of SLM-fabricated Ti-6Al-4V alloys was analyzed,and the electron backscatter diffraction technique was used to investigate the influence of different grain types and orientations on the stress-strain distribution at various scales.Results reveal that in room-temperature compression tests at a strain rate of 10^(-3) s^(-1),both the compressive yield strength and microhardness vary along the deposition direction,indicating a certain degree of mechanical property anisotropy.The alloy exhibits a columnar microstructure;along the deposition direction,the grains appear equiaxed,and they have internal hexagonal close-packed(hcp)α/α'martensitic structure.α'phase has a preferential orientation approximately along the<0001>direction.Anisotropy arises from the high aspect ratio of columnar grains,along with the weak texture of the microstructure and low symmetry of the hcp crystal structure.展开更多
Conventional ignition methods are proving to be ineffective for low-sensitivity energetic materials,highlighting the need to investigate alternative ignition systems,such as laser-based techniques.Over the past decade...Conventional ignition methods are proving to be ineffective for low-sensitivity energetic materials,highlighting the need to investigate alternative ignition systems,such as laser-based techniques.Over the past decade,lasers have emerged as a promising solution,providing focused energy beams for controllable,efficient,and reliable ignition in the field of energetic materials.This study presents a comparative analysis of two state-of-the-art ignition approaches:direct laser ignition and laser-driven flyer ignition.Experiments were performed using a Neodymium-doped Yttrium Aluminum Garnet(Nd:YAG)laser at different energy beam levels to systematically evaluate ignition onset.In the direct laser ignition test setup,the laser beam was applied directly to the energetic tested material,while laserdriven flyer ignition utilized 40 and 100μm aluminum foils,propelled at velocities ranging from 300 to 1250 m/s.Comparative analysis with the Lawrence and Trott model substantiated the velocity data and provided insight into the ignition mechanisms.Experimental results indicate that the ignition time for the laser-driven flyer method was significantly shorter,with the pyrotechnic composition achieving complete combustion faster compared to direct laser ignition.Moreover,precise ignition thresholds were determined for both methods,providing critical parameters for optimizing ignition systems in energetic materials.This work elucidates the advantages and limitations of each technique while advancing next-generation ignition technology,enhancing the reliability and safety of propulsion systems.展开更多
The 193 nm deep-ultraviolet(DUV)laser plays a critical role in advanced semiconductor chip manufacturing[1,2],micro-nano material characterization[3,4]and biomedical analysis[5,6],due to its high spatial resolution an...The 193 nm deep-ultraviolet(DUV)laser plays a critical role in advanced semiconductor chip manufacturing[1,2],micro-nano material characterization[3,4]and biomedical analysis[5,6],due to its high spatial resolution and short wavelength.Efficient and compact 193 nm DUV laser source thus becomes a hot research area.Currently,193 nm Ar F excimer gas laser is widely employed in DUV lithography systems and serves as the enabling technology for 7 and 5 nm semiconductor fabrication.展开更多
Based on the characteristics of laser-induced surface ignition,energetic photosensitive films show promising potential to meet the ignition requirements of various energetic materials(EMs).In this study,DATNBI/ferric ...Based on the characteristics of laser-induced surface ignition,energetic photosensitive films show promising potential to meet the ignition requirements of various energetic materials(EMs).In this study,DATNBI/ferric alginate(DI/FeA),DI/cobalt alginate(DI/CoA),and DI/nickel alginate(DI/Ni A)films are fabricated by employing sodium alginate(SA)with a three-dimensional network structure as the film matrix,via ionic cross-linking of SA with Fe^(3+),Co^(2+),and Ni^(2+)ions.The study demonstrates that the ionic cross-linking enhances the hydrophobic performance of the films,with the water contact angle increasing from 82.1??to 123.5??.Concurrently,the films'near-infrared(NIR)light absorption improved.Furthermore,transition metal ions facilitate accelerated electron transfer,thereby catalyzing the thermal decomposition of DATNBI.Under 1064 nm laser irradiation,the DI/Fe A film exhibits exceptional combustion performance,with an ignition delay time as low as 76 ms.It successfully acts as an NIR laser ignition medium to initiate the self-sustained combustion of CL-20.This study demonstrates the synergistic realization of enhanced hydrophobicity,improved photosensitivity,and promoted catalytic decomposition through microstructural design of the material,providing new insights for the design of additive-free EMs in laser ignition applications.展开更多
The latest generation of aero engines has set higher standards for thrust-to-weight ratio and energy conversion efficiency,making it imperative to address the challenge of efficiently and accurately machining film coo...The latest generation of aero engines has set higher standards for thrust-to-weight ratio and energy conversion efficiency,making it imperative to address the challenge of efficiently and accurately machining film cooling holes.It has been demonstrated that conventional long-pulse lasers are incapable of meeting the elevated quality surface finish requirements for these holes,a consequence of the severe thermal defects.The employment of backside water-assisted laser drilling technology confers a number of distinct advantages in terms of mitigating laser thermal damage,thus representing a highly promising solution to this challenge.However,significant accumulation of bubbles and machining products during the backside water-assisted laser drilling process has been demonstrated to have a detrimental effect on laser transmission and machining stability,thereby reducing machining quality.In order to surmount these challenges,a novel method has been proposed,namely an ultrasonic shock water flow-assisted picosecond laser drilling technique.Numerical models for ultrasonic acoustic streaming and particle tracking for machining product transport have been established to investigate the mechanism.The simulation results demonstrated that the majority of the machining products could rapidly move away from the machining area because of the action of acoustic streaming,thereby avoiding the accumulation of bubbles and products.Subsequent analysis,comparing the process performance in micro-hole machining,confirmed that the ultrasonic field could effectively eliminate bubble and chip accumulation,thus significantly improving micro-hole quality.Furthermore,the impact of ultrasonic and laser parameters on micro-hole quality under varying machining methods was thoroughly investigated.The findings demonstrated that the novel methodology outlined in this study yielded superior-quality micro-holes at elevated ultrasonic and laser power levels,in conjunction with reduced laser frequency and scanning velocity.The taper of the micro-holes produced by the new method was reduced by more than 25%compared with the other conventional methods.展开更多
A RadioFrequency Quadrupole(RFQ)cooler-buncher system was developed and implemented in a collinear laser spectroscopy setup.This system converts a continuous ion beam into short bunches while enhancing the beam qualit...A RadioFrequency Quadrupole(RFQ)cooler-buncher system was developed and implemented in a collinear laser spectroscopy setup.This system converts a continuous ion beam into short bunches while enhancing the beam quality and reducing the energy spread.The functionality of the RFQ cooler buncher was verified through offline tests with stable rubidium and indium beams delivered from a surface ion source and a laser ablation ion source,respectively.Bunched ion beams with a full width at half maximum of approximately 2μs in the time-of-flight spectrum were successfully achieved with a transmission efficiency exceeding 60%.The implementation of the RFQ cooler-buncher system also significantly improved the overall transmission efficiency of the collinear laser spectroscopy setup.展开更多
Tellurene,a chiral chain semiconductor with a narrow bandgap and exceptional strain sensitivity,emerges as a pivotal material for tailoring electronic and optoelectronic properties via strain engineering.This study el...Tellurene,a chiral chain semiconductor with a narrow bandgap and exceptional strain sensitivity,emerges as a pivotal material for tailoring electronic and optoelectronic properties via strain engineering.This study elucidates the fundamental mechanisms of ultrafast laser shock imprinting(LSI)in two-dimensional tellurium(Te),establishing a direct relationship between strain field orientation,mold topology,and anisotropic structural evolution.This is the first demonstration of ultrafast LSI on chiral chain Te unveiling orientation-sensitive dislocation networks.By applying controlled strain fields parallel or transverse to Te’s helical chains,we uncover two distinct deformation regimes.Strain aligned parallel to the chain’s direction induces gliding and rotation governed by weak interchain interactions,preserving covalent intrachain bonds and vibrational modes.In contrast,transverse strain drives shear-mediated multimodal deformations—tensile stretching,compression,and bending—resulting in significant lattice distortions and electronic property modulation.We discovered the critical role of mold topology on deformation:sharp-edged gratings generate localized shear forces surpassing those from homogeneous strain fields via smooth CD molds,triggering dislocation tangle formation,lattice reorientation,and inhomogeneous plastic deformation.Asymmetrical strain configurations enable localized structural transformations while retaining single-crystal integrity in adjacent regions—a balance essential for functional device integration.These insights position LSI as a precision tool for nanoscale strain engineering,capable of sculpting 2D material morphologies without compromising crystallinity.By bridging ultrafast mechanics with chiral chain material science,this work advances the design of strain-tunable devices for next-generation electronics and optoelectronics,while establishing a universal framework for manipulating anisotropic 2D systems under extreme strain rates.This work discovered crystallographic orientation-dependent deformation mechanisms in 2D Te,linking parallel strain to chain gliding and transverse strain to shear-driven multimodal distortion.It demonstrates mold geometry as a critical lever for strain localization and dislocation dynamics,with sharp-edged gratings enabling unprecedented control over lattice reorientation.Crucially,the identification of strain field conditions that reconcile severe plastic deformation with single-crystal retention offers a pathway to functional nanostructure fabrication,redefining LSI’s potential in ultrafast strain engineering of chiral chain materials.展开更多
In-situ formed high Mn steel coating reinforced by carbides was formed by laser surface alloying(LSA).Laser alloyed layers on 1Cr18Ni9Ti steel with Mn+W_(2)C(specimen A),Mn+NiWC(specimen B)and Mn+SiC(specimen C)powder...In-situ formed high Mn steel coating reinforced by carbides was formed by laser surface alloying(LSA).Laser alloyed layers on 1Cr18Ni9Ti steel with Mn+W_(2)C(specimen A),Mn+NiWC(specimen B)and Mn+SiC(specimen C)powders were fabricated to improve the wear and corrosion behavior of 1Cr18Ni9Ti steel blades in high speed mixers.Microstructure evolution,phases,element distribution,microhardness,wear and corrosion behavior of the laser alloyed layers were investigated.Results indicated that high Mn steel matrix composites with undissolved W_(2)C,WC and other in-situ formed carbides were formed by LSA with Mn+W_(2)C and Mn+NiWC while SiC totally dissolved into the high Mn matrix when adding Mn+SiC.Ni as the binding phase in Ni-WC powder decreased the crack sensitivity of the alloyed layer as compared with the addition of W_(2)C powder.An improvement in average microhardness was achieved in the matrix in specimen A,B and C,with the value of 615,602 and 277 HV_(0.5),while that of the substrate was 212 HV_(0.5).The increase of microhardness,wear and corrosion resistance is highly corelated to microstructure,formed phases,type and content of carbides,micro-hardness and toughness of the alloyed layers.展开更多
基金funded by the Priority Academic Program Development of Jiangsu Higher Education Institution(Grant No.2014-37)the Jiangsu Provincial Health and Family Planning Commission(No.H201535)Orofacial Pain and TMD Research Unit,Institute of Stomatology,Affiliated Hospital of Stomatology,Nanjing Medical University,for their support
文摘Low-level laser therapy(LLLT) may have an effect on the pain associated with orthodontic treatment. The aim of this study was to evaluate the effect of LLLT on pain and somatosensory sensitization induced by orthodontic treatment. Forty individuals(12–33 years old; mean ± standard deviations: 20.8 ± 5.9 years) scheduled to receive orthodontic treatment were randomly divided into a laser group(LG) or a placebo group(PG)(1:1). The LG received LLLT(810-nm gallium-aluminium-arsenic diode laser in continuous mode with the power set at 400 mW, 2 J·cm–2) at 0 h, 2 h, 24 h, 4 d, and 7 d after treatment, and the PG received inactive treatment at the same time points. In both groups, the non-treated side served as a control. A numerical rating scale(NRS) of pain, pressure pain thresholds(PPTs), cold detection thresholds(CDTs), warmth detection thresholds(WDTs), cold pain thresholds(CPTs), and heat pain thresholds(HPTs) were tested on both sides at the gingiva and canine tooth and on the hand. The data were analysed by a repeated measures analysis of variance(ANOVA). The NRS pain scores were significantly lower in the LG group(P = 0.01). The CDTs,CPTs, WDTs, HPTs, and PPTs at the gingiva and the PPTs at the canine tooth were significantly less sensitive on the treatment side of the LG compared with that of the PG(P < 0.033). The parameters tested also showed significantly less sensitivity on the nontreatment side of the LG compared to that of the PG(P < 0.043). There were no differences between the groups for any quantitative sensory testing(QST) measures of the hand. The application of LLLT appears to reduce the pain and sensitivity of the tooth and gingiva associated with orthodontic treatment and may have contralateral effects within the trigeminal system but no generalized QST effects. Thus, the present study indicated a significant analgesia effect of LLLT application during orthodontic treatment.Further clinical applications are suggested.
文摘Background: Patients commonly develop postoperative pain after total knee arthroplasty(TKA).Acupuncture-related techniques and low-level laser therapy could be beneficial for pain management for older individuals.Objective: To examine the effect of low-level laser acupuncture(LA) in reducing postoperative pain, painrelated interference in daily life, morphine consumption, and morphine-related side effects in older patients with knee osteoarthritis who underwent TKA.Design, setting, participants and intervention: A single-blind randomized placebo-controlled trial was conducted. Patients(N = 82) were recruited and randomly assigned via a computer-generated list to the LA group or a placebo group. The LA group received low-level laser therapy at Sanyinjiao(SP6), Taixi(KI3),Kunlun(BL60), Fengshi(GB31), Futu(ST32) and Neiguan(PC6) after TKA, while the placebo acupuncture group received the same treatment procedure without laser energy output.Main outcome measures: The primary outcome was postoperative pain intensity, and it was measured at baseline and hours 2, 6, 10, 24, 48 and 72 after TKA. The secondary outcomes, including relative pain,postoperative pain-related interference in daily life and morphine consumption, were measured at hours24, 48 and 72 after TKA.Results: Generalized estimating equations revealed significant between-group differences in pain intensity(P = 0.01), and trend differences in pain intensity for the LA group starting at hours 10 to 72(P < 0.05)and morphine consumption at hours 48 and 72(P < 0.05). The changes in pain-related interference in daily life were significant(P < 0.05) at 72 h, with the exception of the parameters for worst pain, mood,and sleep. Nausea and vomiting side effects from morphine had significant between-group differences at hours 10 and 24(P < 0.05).Conclusion: Low-level LA gradually reduced older patients’ postoperative pain intensity and morphine consumption within the first 72 h after their TKA for osteoarthritis. Low-level LA may have benefits as an adjuvant pain management technique for clinical care.Trial registration: ClinicalTrials.gov registration number NCT03995446.
基金FAPESP(Sao Paulo Research Foundation),Grant/Award Number:2011/50686-0National Institute and Technology-Translational Medicine(INCT.TM)CNPq(National Council for Scientific and Technological Development)
文摘Background : Osteoporosis can make bone repair difficult. Low-level laser therapy( LLLT) has been shown to be a promising tool for bone neoformation. This study aimed to analyze the effect of LLLT on calvaria bone defects of ovariectomized rats using stereology. Methods : Fifty-four Wistar rats were subjected to bilateral ovariectomy, and bone defects were created in calvaria after 150 days. The animals were divided into nine groups(n = ?6 per group), and 24 hours after the bone defects were created they received three, six or 12 sessions of LLLT at 0, 20 or 30 J/cm 2, using a 780-nm low-intensity GaAlAs laser. One-way ANOVA followed by Tukey ' s post hoc test was used for data processing. A difference of P < 0.05 was considered statistically significant. The parameters evaluated were osteocyte density( Nv_(ost)), total osteocyte number( Nto ost), trabecular surface density( Sv_t), and trabecular surface area( Sa_t). Results : Data obtained showed that Nto ost, Sv t, and Sa t in group G2 rats were significantly different from G1(0 J/cm^2)( P < 0.05). Compared to group G4, G5 presented higher values for the parameters Sv t and Sa t, and G6 presented significantly higher values for almost all the analyzed parameters( Nv _(ost), Nto_(ost), Sv_t, and Sa t)( P < 0.05). Compared to group G7, G8 showed a higher value only for the parameter Sa t, and G9 showed significantly higher values for parameters Nv ost, Nto ost, Sv_t, and Sa_t. Conclusion : We conclude that LLLT stimulated bone neoformation and contributed to an increase in the total number of osteocytes, especially with a laser energy density of 30 J/cm^2 given for six and 12 sessions.
文摘Peripheral nerve injuries are common in clinical practice because of traumas such as crushing and sectioning. Lesions of the nerve structure result in lost or diminished sensitivity and/or motor activity in the innervated territory. The degree of lesion depends on the specific nerve involved, the magnitude and type of pres- sure exerted, and the duration of the compression. The results of such injuries commonly include axonal degeneration and retro- grade degeneration of the corresponding neurons in the spinal medulla, followed by very slow regeneration （Rochkind et al., 2001）. The adverse effects on the daily activities of patients with a peripheral nerve injury are a determining factor in establishing the goals of early recovery （Rodriguez et al., 2004）.
文摘Objective:To investigate the effect of Kangfuxin Solution(康复新液)combined with low-level laser therapy(LLLT)on cytokines and immune function in patients with radiation-induced oral mucositis.Methods:There were 84 nasopharyngeal carcinoma patients with oral mucositis after intensity-modulated radiation therapy(IMRT)were randomly divided into the control group(CG)and the observation group(OG),with 42 cases in each group.The CG was given LLLT,and the OG was treated with Kangfuxin Solution in addition to LLLT for 10 consecutive days.The healing time of oral mucosa,mucositis grading,oral pain scores,cytokines(interleukin-6,interleukin-1βand tumor necrosis factor-α)and T lymphocyte subsets were compared between the 2 groups before and after treatment.Results:The healing time of oral mucosa in the OG was(6.8±1.4)d,which was significantly shorter than(8.6±1.9)d in the CG(t=4.943,P<0.01).After treatment,the grading of oral mucositis in the OG was better than that in the CG,with a statistically significant difference(Z=2.942,P<0.05).The oral pain scores of the OG was lower than that in the CG at different time points after treatment,and the difference was statistically significant(t=8.207,11.017,P<0.01).After treatment,the levels of IL-6,IL-1βand TNF-αin peripheral blood of the OG were significantly lower than those in the CG(t=5.217,2.775,4.053,P<0.01).There were statistically significant differences in CD4+,CD8+and CD4+/CD8+between the OG and the CG after treatment(t=5.692,6.093,3.658,P<0.01).Conclusion:Kangfuxin Solution combined with LLLT can significantly shorten the healing time of oral mucosal,reduce the grading of oral mucositis,relieve oral pain,reduce inflammatory response and improve the immune function of patients.
文摘Low-level laser therapy (LLLT) or cold laser has been used in medicine for several decades. However, the method utilizes a direct contact of the light beam with a patient. Further research resulted in development of another method that enables remote transmission of the pharmacological properties of a medicament into a human body with the application of low-level laser radiation as the light source. 18 patients with different viral diseases were treated with the antiviral drugs placed into the field formed by the unexplained properties of low-level laser radiation of the “device for transfer of the pharmacological properties of a drug into the patient’s body”. This resulted in improvement of the patient’s condition, the absence of side effects and adverse reactions when using drugs in the proposed device and shortened therapy period for patients with chronic hepatitis C infection and Covid-19 patients. The long-term follow-up of the patients with chronic hepatitis B infection showed that hepatitis B virus remained at low replication levels under the influence of the therapy, which made it possible to avoid such formidable complications of the disease as cirrhosis of the liver and liver cancer.
文摘Acute renal failure has a 50% - 80% mortality rate. Currently, treatment options for this life-threatening disease are limited. Low-level laser therapy (LLLT) has been found to modulate biological activity. The aim of the present study was to investigate the possible beneficial effects of laser application to stem cells in the bone marrow, on the kidneys of rats that had undergone ischemia-reperfusion injury (IRI). IRI was induced by occlusion of the renal artery to 3- and 7-month-old rats for 15 or 30 minutes. In an additional experiment IRI was applied to both kidneys for 20 min each in 2-3-month-old rats. Rats were then divided randomly into two groups of control and laser-treated. Laser therapy (Ga-Al-As 810 nm, 200 mW output for 2 min) was applied to the bone marrow 1 and 7 days post-IRI to the kidneys, and rats were sacrificed 2 weeks later. Histomorphometry and immunohistochemistry were performed on kidney sections and blood markers for kidney function. Quantitative histomorphometric analysis revealed a reduction in dilatation of the renal tubules, restored structural integrity of the renal tubules, and reduced necrosis in the laser-treated rats as compared to the control, non-laser-irradiated group. C-kit positive cell density in kidneys post-IRI and laser-treatment was significantly (p = 0.015) 3.2-fold higher compared to the control group. Creatinine and blood urea nitrogen content were significantly lower in the laser-treated rats as compared to control. It is concluded that LLLT application to the bone marrow (BM) causes a significant increase in the density of mesenchymal stem cells in the kidneys post-IRI, probably by induction of stem cells in the BM, which subsequently migrate to the IRI kidney, significantly reducing the pathological features of the kidney and increasing kidney function post IRI.
文摘Objective: The aim of the study is to evaluate the effect of low-level laser therapy in comparison to compression bandage therapy in the treatment of venous ulcers. Subjects & Methods: This study was carried out in the period from March 2013 to March 2014. The study included 40 adult patients with a diagnosis of venous ulcer classified as C6 according to the clinical classification of CEAP classification. The patients were divided into 2 groups: the first one included 20 patients treated by low-level laser therapy at the Rheumatology and Rehabilitation department, and the second group included 20 patients in whom we use four layers compression bandaging at the vascular surgery department. Results: 32 ulcers were treated in group I and 35 ulcers were treated in group II. The patients of group I were 7 (35%) females and 13 (65%) males, their age range were (24 - 56) years. The patients of group II were 11 (55%) males and 9 (45%) females;their age ranges were (32 - 50) years. Measurements of the ulcers size by (cm2) were taken at the beginning of therapy, at 1 month, at 2 months and at 3 months later on. The calculation of the area of the ulcer was done by using the graph papers to document the ulcer’s perpendicular linear dimensions. According to the size of the ulcer, some ulcers heal within 1 month (15.6%) ulcers in group I, and (28.5%) in group II. Some ulcers heal within 2 months (28%) in group I, and (37%) in group II. The remaining ulcers heal within 3 months or more which are (56%) ulcers in group I, and (34.2%) ulcers in group II. The recurrence rate of chronic venous leg ulcer in compression bandage technique used in group II was the least one as the total number of recurrent cases were 5 (25%), followed by laser therapy used in group I. Conclusion: There was no significant efficacy of the low-level laser therapy over the four layers compression technique in the management of chronic venous ulcers.
基金supported by the National Key Basic Research Program of China(No.2015CB352006)the National Natural Science Foundation of China(No.61335011)+2 种基金the Program for Changjiang Scholars and Innovative Research Team in University(No.IRT1115)the Fujian Province Educational Project B(No.JB14023)the Program for Youth of the Fujian Provincial Health and Family Planning Commission(No.2014-1-2)
文摘Nitric oxide(NO)and nitric oxide synthase(NOS)have an important role in pain signaling transmission in animal models.Low-level laser therapy(LLLT)is known to have an analgesic effect,but the mechanism is unclear.The aim of the study is to investigate the influence of LLLT on NO release and NOS synthesis in dorsal root ganglion(DRG)neurons,in order to find whether LLLI can ameliorate pain through modulating NO production at the cellular level.The results show that in stress conditions,the laser irradiation at 658 nm can modulate NO production in DRG neurons with soma diameter of about 20μm in a short time after illumination,and affect NOS synthesis in a dose-dependent manner.It is demonstrated that LLLT might treat pain by altering NO release directly and indirectly in DRG neurons.
文摘Objective: To study the effect of low-level laser irradiation (LLLI) combined with ferulic acid on the osteoblast differentiation and maturation as well as osteogenesis signaling pathway expression. Methods: The cranium was collected from the SD rats born within 24 h, osteoblasts were separated, cultured and then divided into control group, ferulic acid group, LLLI group, ferulic acid + LLLI group, and the expression osteoblast differentiation markers, proliferation molecules and signaling pathway molecules were detected after continuous treatment with different conditions for three days. Results: 3 d after treatment, the Bax and Bid mRNA expression in ferulic acid group, LLLI group and ferulic acid + LLLI group of cells were significantly lower than those in control group while Bcl-2, CyclinD1, E2F, Col-I, OC and ALP mRNA expression as well as Wnt, β-catenin, Runx2, cAMP and PKA protein expression were significantly higher than those in control group;Bax and Bid mRNA expression in ferulic acid + LLLI group of cells were significantly lower than those in ferulic acid group and LLLI group while Bcl-2, CyclinD1, E2F, Col-I, OC and ALP mRNA expression as well as Wnt, β-catenin, Runx2, cAMP and PKA protein expression were significantly higher than those in ferulic acid group and LLLI group;Col-I, OC, ALP, Bax, Bid, Bcl-2, CyclinD1 and E2F mRNA expression as well as Wnt, β-catenin, Runx2, cAMP and PKA protein expression were not significantly different between ferulic acid group and LLLI group. Conclusion: Low-level laser irradiation (LLLI) combined with ferulic acid can promote osteoblast differentiation and maturation and activate osteogenesis signaling pathway.
基金supported by the Research Start Fund (Grant No.Y02002010)the Central University Basic Scienti¯c Research Project Business Expenses (Grant No.ZYGX2012J114)the National Natural Science Foundation of China (Grant No.61308114).
文摘Low-level laser therapy(LLLT)has been clinically utilized for many indications in medicine requiring protection from el/issue death,stimulation of healing and repair of injuries,pain reduction,swelling and inflammation.Presently,the use of LLLT to treat stroke,traumnatic brain injury and cognitive dysfunction are attracting growing interest.Near infrared light is capable of penetrating into the cerebral cortex,allowing noninvasive treatments to be caried out with few treatment-related adverse events.Optimization of LLLT treatment flfect is a crucial isse of this field;however,only a few experimental tests on mice for wavelength selection have been reported.We addressed this ssue by low-ost,straightforward and quantitative comparisons on light dosage distribution within visible Chinese human head by Monte Carlo modeling of near infrared light propagation.Optimized selection in wavelength,beam type and size were given based on comparisons among frequently used setups(ie,wavelengths:660,810 and 980 nm;beam type:Gaussian and flat beamn;beam diameter:2,4 and 6 cm).This study provided an fficient way for guiding the optimization of LLLT setup and selection on wavelength,beam type and size for clinical brain LLLT.
基金Shaanxi Province Qin Chuangyuan“Scientist+Engineer”Team Construction Project(2022KXJ-071)2022 Qin Chuangyuan Achievement Transformation Incubation Capacity Improvement Project(2022JH-ZHFHTS-0012)+8 种基金Shaanxi Province Key Research and Development Plan-“Two Chains”Integration Key Project-Qin Chuangyuan General Window Industrial Cluster Project(2023QCY-LL-02)Xixian New Area Science and Technology Plan(2022-YXYJ-003,2022-XXCY-010)2024 Scientific Research Project of Shaanxi National Defense Industry Vocational and Technical College(Gfy24-07)Shaanxi Vocational and Technical Education Association 2024 Vocational Education Teaching Reform Research Topic(2024SZX354)National Natural Science Foundation of China(U24A20115)2024 Shaanxi Provincial Education Department Service Local Special Scientific Research Program Project-Industrialization Cultivation Project(24JC005,24JC063)Shaanxi Province“14th Five-Year Plan”Education Science Plan,2024 Project(SGH24Y3181)National Key Research and Development Program of China(2023YFB4606400)Longmen Laboratory Frontier Exploration Topics Project(LMQYTSKT003)。
文摘A dual-phase synergistic enhancement method was adopted to strengthen the Al-Mn-Mg-Sc-Zr alloy fabricated by laser powder bed fusion(LPBF)by leveraging the unique advantages of Er and TiB_(2).Spherical powders of 0.5wt%Er-1wt%TiB_(2)/Al-Mn-Mg-Sc-Zr nanocomposite were prepared using vacuum homogenization technique,and the density of samples prepared through the LPBF process reached 99.8%.The strengthening and toughening mechanisms of Er-TiB_(2)were investigated.The results show that Al_(3)Er diffraction peaks are detected by X-ray diffraction analysis,and texture strength decreases according to electron backscatter diffraction results.The added Er and TiB_(2)nano-reinforcing phases act as heterogeneous nucleation sites during the LPBF forming process,hindering grain growth and effectively refining the grains.After incorporating the Er-TiB_(2)dual-phase nano-reinforcing phases,the tensile strength and elongation at break of the LPBF-deposited samples reach 550 MPa and 18.7%,which are 13.4%and 26.4%higher than those of the matrix material,respectively.
基金National Natural Science Foundation of China(51504138,51674118,52271177)Hunan Provincial Natural Science Foundation of China(2023JJ50181)Supported by State Key Laboratory of Materials Processing and Die&Mould Technology,Huazhong University of Science and Technology(P2024-022)。
文摘To explore the formation mechanism of anisotropy in Ti-6Al-4V alloy fabricated by selective laser melting(SLM),the compressive mechanical properties,microhardness,microstructure,and crystallographic orientation of the alloy across different planes were investigated.The anisotropy of SLM-fabricated Ti-6Al-4V alloys was analyzed,and the electron backscatter diffraction technique was used to investigate the influence of different grain types and orientations on the stress-strain distribution at various scales.Results reveal that in room-temperature compression tests at a strain rate of 10^(-3) s^(-1),both the compressive yield strength and microhardness vary along the deposition direction,indicating a certain degree of mechanical property anisotropy.The alloy exhibits a columnar microstructure;along the deposition direction,the grains appear equiaxed,and they have internal hexagonal close-packed(hcp)α/α'martensitic structure.α'phase has a preferential orientation approximately along the<0001>direction.Anisotropy arises from the high aspect ratio of columnar grains,along with the weak texture of the microstructure and low symmetry of the hcp crystal structure.
文摘Conventional ignition methods are proving to be ineffective for low-sensitivity energetic materials,highlighting the need to investigate alternative ignition systems,such as laser-based techniques.Over the past decade,lasers have emerged as a promising solution,providing focused energy beams for controllable,efficient,and reliable ignition in the field of energetic materials.This study presents a comparative analysis of two state-of-the-art ignition approaches:direct laser ignition and laser-driven flyer ignition.Experiments were performed using a Neodymium-doped Yttrium Aluminum Garnet(Nd:YAG)laser at different energy beam levels to systematically evaluate ignition onset.In the direct laser ignition test setup,the laser beam was applied directly to the energetic tested material,while laserdriven flyer ignition utilized 40 and 100μm aluminum foils,propelled at velocities ranging from 300 to 1250 m/s.Comparative analysis with the Lawrence and Trott model substantiated the velocity data and provided insight into the ignition mechanisms.Experimental results indicate that the ignition time for the laser-driven flyer method was significantly shorter,with the pyrotechnic composition achieving complete combustion faster compared to direct laser ignition.Moreover,precise ignition thresholds were determined for both methods,providing critical parameters for optimizing ignition systems in energetic materials.This work elucidates the advantages and limitations of each technique while advancing next-generation ignition technology,enhancing the reliability and safety of propulsion systems.
基金supported by the National Natural Science Foundation of China(Grant Nos.62450006,62304217,62274157,62127807,62234011,62034008,62074142,62074140)Tianshan Innovation Team Program(Grant No.2022TSYCTD0005)+1 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0880000)Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant Nos.2023124,Y2023032)。
文摘The 193 nm deep-ultraviolet(DUV)laser plays a critical role in advanced semiconductor chip manufacturing[1,2],micro-nano material characterization[3,4]and biomedical analysis[5,6],due to its high spatial resolution and short wavelength.Efficient and compact 193 nm DUV laser source thus becomes a hot research area.Currently,193 nm Ar F excimer gas laser is widely employed in DUV lithography systems and serves as the enabling technology for 7 and 5 nm semiconductor fabrication.
基金supported by Research Fund of SWUST for PhD(Grant No.22zx7175)Sichuan Science and Technology Program(Grant No.2024NSFSC1097)。
文摘Based on the characteristics of laser-induced surface ignition,energetic photosensitive films show promising potential to meet the ignition requirements of various energetic materials(EMs).In this study,DATNBI/ferric alginate(DI/FeA),DI/cobalt alginate(DI/CoA),and DI/nickel alginate(DI/Ni A)films are fabricated by employing sodium alginate(SA)with a three-dimensional network structure as the film matrix,via ionic cross-linking of SA with Fe^(3+),Co^(2+),and Ni^(2+)ions.The study demonstrates that the ionic cross-linking enhances the hydrophobic performance of the films,with the water contact angle increasing from 82.1??to 123.5??.Concurrently,the films'near-infrared(NIR)light absorption improved.Furthermore,transition metal ions facilitate accelerated electron transfer,thereby catalyzing the thermal decomposition of DATNBI.Under 1064 nm laser irradiation,the DI/Fe A film exhibits exceptional combustion performance,with an ignition delay time as low as 76 ms.It successfully acts as an NIR laser ignition medium to initiate the self-sustained combustion of CL-20.This study demonstrates the synergistic realization of enhanced hydrophobicity,improved photosensitivity,and promoted catalytic decomposition through microstructural design of the material,providing new insights for the design of additive-free EMs in laser ignition applications.
基金supported by the National Natural Science Foundation of China(No.52205468,No.52275431,No.52375186)China Postdoctoral Science Foundation(No.2025M771349)Zhejiang Province Natural Science Foundation(No.LD22E050001)。
文摘The latest generation of aero engines has set higher standards for thrust-to-weight ratio and energy conversion efficiency,making it imperative to address the challenge of efficiently and accurately machining film cooling holes.It has been demonstrated that conventional long-pulse lasers are incapable of meeting the elevated quality surface finish requirements for these holes,a consequence of the severe thermal defects.The employment of backside water-assisted laser drilling technology confers a number of distinct advantages in terms of mitigating laser thermal damage,thus representing a highly promising solution to this challenge.However,significant accumulation of bubbles and machining products during the backside water-assisted laser drilling process has been demonstrated to have a detrimental effect on laser transmission and machining stability,thereby reducing machining quality.In order to surmount these challenges,a novel method has been proposed,namely an ultrasonic shock water flow-assisted picosecond laser drilling technique.Numerical models for ultrasonic acoustic streaming and particle tracking for machining product transport have been established to investigate the mechanism.The simulation results demonstrated that the majority of the machining products could rapidly move away from the machining area because of the action of acoustic streaming,thereby avoiding the accumulation of bubbles and products.Subsequent analysis,comparing the process performance in micro-hole machining,confirmed that the ultrasonic field could effectively eliminate bubble and chip accumulation,thus significantly improving micro-hole quality.Furthermore,the impact of ultrasonic and laser parameters on micro-hole quality under varying machining methods was thoroughly investigated.The findings demonstrated that the novel methodology outlined in this study yielded superior-quality micro-holes at elevated ultrasonic and laser power levels,in conjunction with reduced laser frequency and scanning velocity.The taper of the micro-holes produced by the new method was reduced by more than 25%compared with the other conventional methods.
基金supported by the National Natural Science Foundation of China(Nos.12027809,12350007)National Key R&D Program of China(Nos.2022YFA1605100,2023YFA1606403,and 2023YFE0101600)+1 种基金New Cornerstone Science Foundation through the XPLORER PRIZEfunding from the European Research Council(ERC)under the European Union’s Horizon 2020 research and innovation program under grant agreement No.679038.
文摘A RadioFrequency Quadrupole(RFQ)cooler-buncher system was developed and implemented in a collinear laser spectroscopy setup.This system converts a continuous ion beam into short bunches while enhancing the beam quality and reducing the energy spread.The functionality of the RFQ cooler buncher was verified through offline tests with stable rubidium and indium beams delivered from a surface ion source and a laser ablation ion source,respectively.Bunched ion beams with a full width at half maximum of approximately 2μs in the time-of-flight spectrum were successfully achieved with a transmission efficiency exceeding 60%.The implementation of the RFQ cooler-buncher system also significantly improved the overall transmission efficiency of the collinear laser spectroscopy setup.
基金financial support from NSF ExpandQISE program.The synthesis of tellurene was supported by NSF under grant no.CMMI-2046936supports from Purdue Research Foundation.
文摘Tellurene,a chiral chain semiconductor with a narrow bandgap and exceptional strain sensitivity,emerges as a pivotal material for tailoring electronic and optoelectronic properties via strain engineering.This study elucidates the fundamental mechanisms of ultrafast laser shock imprinting(LSI)in two-dimensional tellurium(Te),establishing a direct relationship between strain field orientation,mold topology,and anisotropic structural evolution.This is the first demonstration of ultrafast LSI on chiral chain Te unveiling orientation-sensitive dislocation networks.By applying controlled strain fields parallel or transverse to Te’s helical chains,we uncover two distinct deformation regimes.Strain aligned parallel to the chain’s direction induces gliding and rotation governed by weak interchain interactions,preserving covalent intrachain bonds and vibrational modes.In contrast,transverse strain drives shear-mediated multimodal deformations—tensile stretching,compression,and bending—resulting in significant lattice distortions and electronic property modulation.We discovered the critical role of mold topology on deformation:sharp-edged gratings generate localized shear forces surpassing those from homogeneous strain fields via smooth CD molds,triggering dislocation tangle formation,lattice reorientation,and inhomogeneous plastic deformation.Asymmetrical strain configurations enable localized structural transformations while retaining single-crystal integrity in adjacent regions—a balance essential for functional device integration.These insights position LSI as a precision tool for nanoscale strain engineering,capable of sculpting 2D material morphologies without compromising crystallinity.By bridging ultrafast mechanics with chiral chain material science,this work advances the design of strain-tunable devices for next-generation electronics and optoelectronics,while establishing a universal framework for manipulating anisotropic 2D systems under extreme strain rates.This work discovered crystallographic orientation-dependent deformation mechanisms in 2D Te,linking parallel strain to chain gliding and transverse strain to shear-driven multimodal distortion.It demonstrates mold geometry as a critical lever for strain localization and dislocation dynamics,with sharp-edged gratings enabling unprecedented control over lattice reorientation.Crucially,the identification of strain field conditions that reconcile severe plastic deformation with single-crystal retention offers a pathway to functional nanostructure fabrication,redefining LSI’s potential in ultrafast strain engineering of chiral chain materials.
文摘In-situ formed high Mn steel coating reinforced by carbides was formed by laser surface alloying(LSA).Laser alloyed layers on 1Cr18Ni9Ti steel with Mn+W_(2)C(specimen A),Mn+NiWC(specimen B)and Mn+SiC(specimen C)powders were fabricated to improve the wear and corrosion behavior of 1Cr18Ni9Ti steel blades in high speed mixers.Microstructure evolution,phases,element distribution,microhardness,wear and corrosion behavior of the laser alloyed layers were investigated.Results indicated that high Mn steel matrix composites with undissolved W_(2)C,WC and other in-situ formed carbides were formed by LSA with Mn+W_(2)C and Mn+NiWC while SiC totally dissolved into the high Mn matrix when adding Mn+SiC.Ni as the binding phase in Ni-WC powder decreased the crack sensitivity of the alloyed layer as compared with the addition of W_(2)C powder.An improvement in average microhardness was achieved in the matrix in specimen A,B and C,with the value of 615,602 and 277 HV_(0.5),while that of the substrate was 212 HV_(0.5).The increase of microhardness,wear and corrosion resistance is highly corelated to microstructure,formed phases,type and content of carbides,micro-hardness and toughness of the alloyed layers.
