Effect Of Laser Irradiation Research Articles

Physical justification of the safety of using a surgical laser with a wavelength of 445nm during stapedoplasty

Abstract Introduction. Surgical lasers with different wavelengths are used in the surgical treatment of patients with otosclerosis. There are undoubted advantages of using surgical lasers during stapedoplasty at its various stages. At the same time, there is a risk of negative consequences for the structures of the inner ear due to the transition of light energy into thermal energy. Currently, the search for modern optimal surgical lasers for stapedoplasty continues. Aim ofthe study. To substantiate the safety of using a laser beam with a wavelength of 445nm during stapedoplasty using an experimental physical model. Materials and methods. Together with physicists from the Russian Engineering Club LLC, a physical experimental model was created to theoretically substantiate the use of a surgical laser with a wavelength of 445nm during stapedoplasty at its various stages. Results. Based on the physical calculations carried out during our study, we came to important conclusions regarding the effect of laser radiation on the structures of the inner ear during the stapedoplasty process. It was found that even if the value of the parasitic (damaging) radiation energy is 10 W (maximum value) with an average pulse duration used for perforation of the footplate of the stirrup is 0.15 s, then its effect will not lead to any significant thermal effect on the perilymph. Conclusions. The obtained data serve as a basis for further research and improvement of laser technologies in the field of otosurgery. As part of our study, we anticipate the need for additional histological analysis based on the results obtained. Despite encouraging findings regarding the safety of parasitic laser radiation in the context of thermal exposure to perilymph, histological examination represents an important next step for a deeper understanding of structural changes in the tissues of the inner ear.

Effects of Laser Irradiation in High-Speed Gas Flow for Surface Treatments of Copper

In this study, the impacts of laser irradiation on the surface morphology and hardness of copper (Cu) are investigated under various environments, including air, vacuum, and high-pressure gas flow through a supersonic nozzle. After irradiating Cu targets with laser pulses with energy of 30, 60, and 90 mJ/pulse, the surface structures of the targets are analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The SEM analysis reveals diverse surface morphologies, including micro-cones, cavities, droplets, ripples, and island-like structures, depending on laser energy and environments. The XRD analysis provides insights into the structural changes induced by laser irradiation. The results indicate a significant enhancement in microhardness by a factor of 2.77, which is attributed to the surface and structural modifications incurred under various environments. In addition, the XRD analysis reveals a shift in the residual stress in the surface layers of copper from tensile before laser irradiation to compressive afterwards, highlighting the effectiveness of laser surface treatment in inducing favorable mechanical properties.

Diode Laser Irradiation Effects on Physical Properties of Titanium Dioxide Nano Fillers Doped Polyvinyl Alcohol Films

Study effect of diode laser (wavelength 650 nm) irradiation for different irradiant times (0.25, 0.5, 1.00, 3.00, and 4.00 hrs) on the physical properties of titanium dioxide (TiO2) possess particle size of 15.7 nm doped polyvinyl alcohol (PVA) films were experimentally investigated. The solution casting process has been utilized to create as-prepared TiO2/PVA nanocomposite films. Ultraviolet-Visible (UV-Vis) spectroscopy investigates the samples' optical characteristics by analyzing optical absorption spectra in a wavelength range of (200 - 900 nm) at room temperature (RT) of 300 K. The PVA matrix could be used to describe the influence. All optical constants produced artificially through laser radiation, like absorption, refraction index, extinction coefficient and complex dielectric constants, have decreased with increasing radiation times. On the contrary of optical energy gap they increased with increasing radiation times, according to the study's findings. TiO2 Nanoparticles (NPs) additions significantly impacted the PVA host's optical characteristics. When FTIR-spectrum regarding the TiO2/PVA nanocomposite films was examined in various ratios of irradiation times, the peak positions or bonds did not change; instead, they became smaller or larger as the irradiation time increased.

Antibacterial effect of semiconductor laser radiation against the strains of S. aureus and P. aeruginosa, leading pathogens in osteomyelitis

Introduction The study of the antibacterial effect of photodynamic therapy against the leading pathogens of chronic osteomyelitis is one of the promising directions today.Purpose of the work was to evaluate the antibacterial effect against the strains of Staphylococcus aureus and Pseudomonas aeruginosa with the ALOD-01 laser system in the presence of photodithazine.Materials and methods The object of the study was 24-hour archival cultures of gram-positive and gram-negative microorganisms belonging to two taxa: Staphylococcus aureus (25923), Pseudomonas aeruginosa (27853). The antibacterial effect after the exposure to laser radiation in the presence of photodithazine on the microbial cells of the studied cultures was assessed by the absence of microorganism growth in the area of the light beam.Results Laser exposure in combination with photodithazine (concentration 0.5–1.0 mg/ml) on S. aureus for two minutes at 200–300 J achieved a bactericidal effect in the beam area. A bactericidal effect on the entire surface of the Petri dish was achieved with light exposure of 400 J for 5 minutes and a photodithazine concentration of 1.0 mg/ml. Laser exposure for 2 minutes in the presence of photodithazine at a concentration of 0.5 mg/ml and 1 mg/ml did not have an antibacterial effect on P. aeruginosa strains. Continuous growth of microorganisms was observed on the dish. Increasing the light dose and exposure time contributed to a decrease in the growth of microbial cells. A bactericidal effect was obtained only in the center of the dish in treating the bacterial suspension with photodithazine at a concentration of 5 mg/ml.Discussion The effectiveness of PDT depends on the type of microorganisms, the anatomical location of the infection site, as well as the properties of the photosensitizer and the laser used. Depending on the structure of the cell wall, different susceptibility of bacteria to photodynamic effects is observed.Conclusion S. aureus strains can be successfully photoinactivated using photodithazine. For P. aeruginosa strains, it was not possible to find a regime in which microbial cell growth was absent throughout the dish. The photodynamic reaction occurs only when adequate doses of light energy act on the photosentisizer in the presence of oxygen in the medium, while the photodynamic damage is local and the bactericidal effect is limited by the zone of light exposure.

Laser and remineralising agents in dental erosion: a systematic review and meta-analysis.

This systematic review aimed to evaluate, by means of statistical comparison between selected studies, the effectiveness of laser irradiation on dental erosion applied alone or in combination with anti-erosive agents (fluoride, Acidulated phosphate fluoride APF and CPP-amorphous calcium fluoride phosphate CPP-ACFP), through optical profilometry and microhardness measurement. The searching strategy was conducted according to the International PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, to answer research ques-tions regarding the effectiveness of lasers used in the context of dental erosion (such as Nd:YAG, CO2, Er:YAG, Er,Cr:YSGG, Diode, and Argon Ion lasers). A comprehensive and unrestricted sys-tematic searching was performed using the electronic databases of PubMed and Cochrane Library, for all articles published up to the end of January 2023. The review record was registered by the International prospective register of systematic reviews (PROSPERO) under the identification number CRD408639. Change in microhardness for the lasers group, irrespective of the type of laser used in the sample, was significantly greater compared with the one in the control group. Regards microhardness, the combination of Laser and APF gel showed promising results compared to APF gel agent.

Effect of laser irradiation during in-office tooth bleaching on surface properties of resin-based restorative materials.

This study evaluated the changes in surface properties of three resin-based restorative materials after two laser-assisted, in-office tooth bleaching protocols using erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) or diode (980nm) lasers. A nanohybrid composite (Enamel Plus HRi), a Bis-GMA-free composite (Enamel Plus HRi Bio Function), and a resin-matrix CAD-CAM ceramic (Shofu Block HC) were tested. Forty specimens for each material were prepared and divided into four groups (n=10/group). The control specimens did not undergo any bleaching treatment, whereas group 2 received bleaching with 40% hydrogen peroxide (H2O2), while groups 3 and 4 underwent the same bleaching procedure with the use of diode (980nm) or Er,Cr:YSGG lasers, respectively. Surface microhardness and roughness measurements were conducted using a Vickers tester and an optical profilometer. Microhardness was lower in bleached specimens, with the nanohybrid composite exhibiting the largest difference from the no bleaching group. For the Bis-GMA-free composite the microhardness difference between no bleaching and laser-assisted bleaching were smaller than seen for the conventional bleaching technique. Surface roughness was higher in bleached specimens, with nanohybrid composite showing the largest differences from the control specimens. The examined laser-assisted tooth bleaching protocols were found not to impact surface microhardness and roughness of the tested resin-based specimens and they are deemed suitable for clinical use.

Effect of Laser Irradiation with 532 nm Wavelength on The Optical Properties of PVA/MR Solutions

Background: This work aims to study the impact of 532 nm laser irradiating on the optical properties of the Polyvinyl alcohol/ Methyl Red (PVA/MR) solution before and after laser irradiation 32mW with various times (0, 20, 30 and 40) minutes. Materials and Methods: The polymer (PVA) powder 500 mg was dissolved in 50 ml distilled water at temperature 80 ˚C and the methyl red (MR) 30 mg was dissolved in 10 ml at temperature 80 ˚C using solution dilution formula . A semiconductor laser with a wavelength of 532 nanometers was used to irradiate the solution. Results: The absorbance, reflectance, and transmittance spectrum of solution prior to and following laser irradiation were recorded. Then, the optical constants and energy gap were calculated. Conclusions: The irradiation with the 532nm laser leads to a break of the bonds (From the absorbance spectrum, it decreases as the irradiation time increases. This indicates the breaking of bonds.) that results in an increase in the transmittance spectrum, and the energy gap.

Effect of 532nm and 589nm Diode-Pumped Solid-State (DPSS) Lasers with Different Doses on Concentration of Total Protein and Albumin in Vitro.

To test the effects of Low-level laser irradiation at 532nm and 589nm with different doses and exposure times on total protein and albumin in blood plasma. This experimental study was conducted from November 2021 to April 2022 at Mustansiriyah University, Baghdad, Iraq, and comprised blood samples from healthy adults. The samples were stored in tubes containing anticoagulant ethylenediaminetetraacetic acid. Photoradiation was managed using green laser 532nm and yellow laser 589nm diode-pumped solid-state lasers with different doses. For total protein test and albumin test, each sample was divided into 3 equal aliquots. The first was control without radiation, the second was irradiated by a laser at 532nm, and the third was irradiated at 589nm with 30J/cm², 50J/cm², 70J/cm² and 90 J/cm² doses of irradiation. All samples were examined by using a spectrophotometer device. Data was analysed using SPSS 25. There were 24 samples from healthy adults in all.The most significant difference in total protein concentration occurred at dose 70J/cm² for both wavelengths compared to the controls (p<0.05). When this optimal dose was applied to the albumin test, a clear decrease in the albumin concentration was found for both 532nm and 589nm lasers (p<0.05). At wavelengths of 532nm and 589nm, the laser light induced processes that caused a reduction in total protein and albumin.

In vitro comparison of low-power diode pumping solid-state laser radiation at 589 and 650 nm on red blood cells suspension viscosity, stability, and deformability.

To investigate the effect of diode-pumped solid-state laser irradiation with yellow 589nm and red 650nm wavelengths on rheological parameters in vitro. The comparative study was conducted between November 2021 and April 2022 at the at the Postgraduate Medical Physics Laboratory, Mustansiriyah University, Baghdad, Iraq, and comprised blood samples from healthy adult volunteers. The samples were divided into 4 aliquots. The first was preserved as a control sample, while the other 3 were exposed to a diode-pumped solid-state laser, delivering the beam for 589nm and 650nm wavelengths at radiation dose 15, 22.5, 33.5J/cm2 for 20, 30 and 45 minutes, and with each laser having a 50mW output power and a 4 mm2 spot diameter. Data was analysed using SPSS (version 24). There were 6 subjects aged 18-60 years. There was no significant difference in the viscosity values between laser wavelengths (p>0.05). Compared to the laser wavelength of 650nm, irradiation with a 589nm wavelength at the same dose resulted in a significant reduction (p<0.009) in deformability. The rigidity index of red blood cell suspension was reduced the most at a radiation dose of 22.5J/cm2 for both lasers compared to the control samples. No significant variations were found in suspended erythrocyte viscosity (p>0.05). The wavelength with 589nm lasers showed more effective influence than its 650nm counterpart in improving the rheological parameters of blood viscosity and erythrocytes deformability.

A comparison study of 589 and 650 nm on improving stored whole blood stability by irradiation with a low-power diode pumping solid-state laser.

To assess the effects of diode-pumped solid-state laser irradiation with 589nm and 650nm wavelengths on the stability of stored red blood cells in vitro. This is an intervention study that was conducted from April to July 2021 at the Physiology and Medical Physics Laboratory, College of Medicine, Mustansiriyah University, Baghdad, Iraq, and comprised samples of healthy, adult human blood that were put in tubes with citrate-phosphate dextrose-adenine as an anticoagulant. The blood sample was divided into eight equal aliquots and stored for 21 days at 4ºC. The stability test was done on days 0, 7, 14 and 21 of storage time for non-irradiated and radiated aliquots. For 15 minutes, the irradiated aliquots were subjected to a diode-pumped solid-state laser with a wavelength of 589nm or a laser with a wavelength of 650nm at frequencies of 30, 50 and 70 J/cm². Data was analysed using SPSS 24. Exposure of the whole blood to 589nm and a radiation dose of 70J/cm², 50J/cm² and 30J/cm² was associated with a significant reduction in the percentage of haemolysis that ranged 23-42% throughout the whole storage time. Exposure of the whole blood to 650nm wavelength low-level laser therapy and a radiation dose of 70J/cm², 50J/cm² and 30J/cm² was associated with much less reduction in the percentage of haemolysis that ranged 5-9% throughout the whole storage time. Both 589nm and to some extent 650nm low-level laser irradiation generally reduced haemolysis. The wavelength of 589nm lasers had a more effective influence than the 650nm counterpart in improving the stored red blood cells.

A comparative study of 589 and 532 nm low level laser irradiation effects on normal human peripheral blood mononuclear cells viability.

To assess how laser light affects blood lymphocyte viability in vitro. The comparative study was conducted from November 2021 to April 2022 at the Department of Medical Physics, Mustansiriyah University, Baghdad, Iraq, and comprised blood samples collected from healthy adults with no medical history of major illnesses or history of taking medications for major diseases.Low-level laser 589nm and 532nm was used at 30 J/cm², 50 J/cm² and 70J/cm² energy intensities and three different post-exposure time; immediately, 1h and 2h after radiation exposure. The viability of normal human lymphocytic cells of the blood was noted. Data was analysed using SPSS 24. The blood samples were drawn from 6 adult male voluteers. The percentage of cells that showed apoptosis post-exposure to 589nm laser was significantly lower than that following exposure to 532nm laser (p<0.05). However, the proportion of apoptotic cells was significantly higher following irradiation with 532nm at varying doses than after irradiation with 589nm (p<0.05). A low-level laser could promote and prevent apoptosis in human peripheral blood cells in a dose- and time-dependent manner.

NIR Laser Irradiation Promotes Osteogenic Differentiation of PDLSCs Through the Activation of TRPV1 Channels and Subsequent Calcium Signaling.

Near-infrared (NIR) irradiation has shown potential to stimulate osteogenic differentiation, but the mechanisms are not fully understood. The study is to investigate the effects of NIR laser irradiation on osteoblastic differentiation. Human periodontal ligament stem cells (hPDLSCs) were cultured in osteogenic medium and exposed to 810 nm NIR laser at 0.5 J/cm2 every 48 h. The transient receptor potential vanilloid (TRPV1) channel inhibitor capsazepine (CPZ) was used to evaluate the role of calcium influx. Osteogenic differentiation was assessed by proliferation (CCK-8), alkaline phosphatase (ALP) activity, mineralization (Alizarin Red), and expression of bone markers by PCR and Western blot over 2 weeks. Intracellular calcium was measured by Fluo-4M dye and flow cytometry. Results showed that NIR irradiation enhanced hPDLSC proliferation, ALP activity, mineralization, and bone marker expression, indicating increased osteogenic differentiation. These effects were inhibited by CPZ. NIR induced a transient rise in intracellular calcium peaking at 3 min, which was blocked by CPZ. In conclusion, this study demonstrates that NIR laser irradiation promotes osteogenic differentiation of PDLSCs through the activation of TRPV1 channels and subsequent calcium signaling. Further research is warranted to optimize the treatment parameters and elucidate the detailed signaling pathways involved, paving the way for the clinical application of NIR therapy in the treatment of bone disorders and periodontal disease.

The elicitation effects of diode and He-Ne laser irradiations on the alleviation of nutrient-deficiency induced damage in anthocyanin-producing red-fleshed apple cell suspension

Purpose We explored the elicitation role of the laser irradiations on the alleviation of nutrient-deficiency induced damage in anthocyanin-producing red-fleshed apple cell suspension in continuous production of anthocyanin. Methods Anthocyanin-producing red-fleshed apple cells were irradiated by 4 intensity levels of red He-Ne (RHNL) and blue diode (BDL) lasers for 20 min. Results Nutrient deficiency indicated negative effect on total soluble proteins (TSP), superoxidase dismutase (SOD) activity, and total phenolics content (TPC) while it displayed a positive effect on malondialdehyde (MDA), total flavonoids content (TFC), O2 -, H2O2 - , and lipoxygenase (LOX) and polyphenol oxidase (PPO) activities in light controls, illustrating oxidative stress. The laser irradiations on suspension cells indicated variable effects on measured parameters and were time of growth-, levels of intensity-, and laser type-dependent. Likewise, the elicitation effects of lasers relied on a critical threshold among ROS generation and antioxidative system which determines the fate of cells against oxidative stress. The same trend was displayed by RHNL at 6.46 mWcm−2 intensity and BDL at 13.73 mWcm−2. These intensities resulted in a significant increase in SOD, APX, POD, and CAT activities and TSP, TPC, TFC, proline, and glycine betaine accumulation, while induced decrease in LOX, and PPO activities and MDA, and ROS generation, alleviating cellular injury from prolonged nutrient deficiency by diminishing lipid peroxidation and oxidative damages of cell membrane. Conclusion Results suggested that lasers application on mitigating nutrient deficiency stress relied on establishing a suitable balance between ROS generation and antioxidative system, which enables the nutrient-starved anthocyanin-producing cells to continuously produce anthocyanin.

Optically Controlled Fine-Tuning Phase Shift Cell Based on Thin-Film Ge2Sb2Te5 for Light Beam Phase Modulation

We present the experimental study of free-space optical control of the optical beam phase shift caused by the formation of a layered structure in an elementary controllable cell made of phase-change material Ge2Sb2Te5 subjected to the controlling effect of pulsed laser radiation. The phase change of the signal optical beam passing through the controlled cell from phase-change material relative to the control beam in the Jamin interferometer is demonstrated.

One-step E-Jet printing of loofah-like ZnO nanostructures by real-time laser zone irradiation

Loofah-like nanostructures have been applied in many fields because of their high specific surface area, high porosity, and low density. Developing additive manufacturing methods for loofah-like nanostructures remains a challenge. This paper proposed a novel E-Jet nanoprinting method with real-time laser zone irradiation, for one-step fabricating of loofah-like ZnO nanostructures. The combination of laser irradiation and electrohydrodynamic effect had been proved in detail by adding laser irradiation to the traditional E-Jet printing process. Printable ZnO inks were prepared. The numerical model of the jetting under the combination of flow field and electric field; and the model of the interaction between laser and printing structure were established respectively. The laser beam irradiated the printing structure in real-time to rapidly absorb energy, resulting in thermal expansion and thermal decomposition. The shock wave generated by laser irradiation induced the physical fragmentation and redistribution of particles in the printed structure. Printing at different laser powers was investigated; and the loofah-like ZnO nanostructures, down to the scale of ∼90 nm, have been directly printed without post-processing. The characteristic morphology and hydrophilic characteristics of the printed structure were studied. This study provided a new way for green and efficient additive fabrication of loofah-like nanostructures, which was of significance for the development of nanofabrication and nanodevices.

Bacterial reduction and temperature increase of titanium dental implant models treated with a 445 nm diode laser: an in vitro study

In this in vitro study, the use of a 445 nm diode laser was investigated for the decontamination of titanium dental implants. Different irradiation protocols and the effect of repetitive laser irradiation on temperature increase and decontamination efficacy were evaluated on titanium implant models. An automated setup was developed to realize a scanning procedure for a full surface irradiation to recapitulate a clinical treatment. Three irradiation parameter sets A (continuous wave, power 0.8 W, duty cycle (DC) 100%, and 5 s), B (pulsed mode, DC 50%, power 1.0 W, and 10 s), and C (pulsed mode, DC 10%, power 3.0 W, and 20 s) were used to treat the rods for up to ten consecutive scans. The resulting temperature increase was measured by a thermal imaging camera and the decontamination efficacy of the procedures was evaluated against Escherichia coli and Staphylococcus aureus, and correlated with the applied laser fluence. An implant’s temperature increase of 10 °C was set as the limit accepted in literature to avoid thermal damage to the surrounding tissue in vivo. Repeated irradiation of the specimens resulted in a steady increase in temperature. Parameter sets A and B caused a temperature increase of 11.27 ± 0.81 °C and 9.90 ± 0.37 °C after five consecutive laser scans, respectively, while parameter set C resulted in a temperature increase of only 8.20 ± 0.53 °C after ten surface scans. The microbiological study showed that all irradiation parameter sets achieved a complete bacterial reduction (99.9999% or 6-log10) after ten consecutive scans, however only parameter set C did not exceed the temperature threshold. A 445 nm diode laser can be used to decontaminate dental titanium rods, and repeated laser irradiation of the contaminated areas increases the antimicrobial effect of the treatment; however, the correct choice of parameters is needed to provide adequate laser fluence while preventing an implant’s temperature increase that could cause damage to the surrounding tissue.

An SEM study on the effect of 9.3-µm CO2 laser on dentinal tubules for hypersensitivity treatment.

In-vitro studies were performed on dentin of extracted human molars to investigate the effectiveness of 9.3μm CO2 laser irradiation to occlude dentinal tubules. The observed occlusion of dentinal tubules with the irradiation was compared with application of three reagents: 2% Sodium Fluoride gel, an aqueous solution of hydroxyapatite nanoparticles and an equal mix of the two. We show that 9.3μm CO2 laser irradiation occludes dentinal tubules, and the use of laser irradiation produces better occlusion of the opened tubules compared to the use of topical reagents. Nine extracted and cleaned human molars were cut to obtain dentin disks of thickness of 3-5mm. Each disc was divided into four quarters, and each quarter served as two samples corresponding to irradiated and non-irradiated group counterparts. Five disks were used to study the effect of various laser irradiation energies on the dentinal tubules to find a good pulse fluence for occlusion of the dentinal tubules, and four disks were used for studying the effects of reagents and irradiation at the pulse fluences found in the first part of the study. The samples were irradiated with a beam diameter of 1mm (1/e2) at 15Hz pulse repetition rate, scanned automatically using a set of scanning mirrors. Samples were imaged using Scanning Electron Microscope (SEM) which were processed to determine tubule diameter. Safety of the irradiation treatment was investigated on 6 samples by measuring pulpal temperature rise. The effect of three topical reagents corresponding to 2% Sodium Fluoride gel (F), Hydroxyapatite nanoparticles (HA) and an equal mix of F and HA (HAF) on dentinal tubule occlusion was evaluated and compared with the laser irradiation. In all examined cases, laser irradiation at a fluence of 0.81J/cm2 resulted in a temperature increase less than 3°C which is safe, and no surface cracking was observed. There is a threshold pulse fluence of 0.27J/cm2 above which, laser produced surface melting. At a pulse fluence of 0.81J/cm2 a layer of recast of melted dentin was formed. Under this layer, peritubular dentin melting and occluding of the dentinal tubules was observed. Application of either F or HA or HAF did not produce visible occlusion effect on open tubules after washing and microbrushing with excess distilled water. 9.3μm CO2 laser irradiation on extracted human molar dentin at pulse fluence of 0.81J./cm2 resulted in tubule area reduction by 97% without rising pulpal temperatures to unsafe levels.

Low-voltage solution-processed Sn-doped CuI neuromorphic transistors with synaptic plasticity and pain mimicked

In this article, SnxCu1−xI thin-film transistors were fabricated on a glass substrate, with CuI doped with varying concentrations of SnI2 serving as the channel and chitosan as the dielectric. When x = 0.06, the device exhibited optimal performance: a current on/off ratio of 2.56 × 105, a subthreshold slope of 31.67 mV/dec, a threshold voltage of 1.33 V, and a saturated field-effect mobility of 21.75 cm2 V−1 s−1. Due to the electric double layer effect of chitosan, the operating voltage of the devices was reduced to below 2 V. Simulations were also conducted on the behavior and functionality of artificial synapses, such as short-term plasticity, long-term plasticity, and paired-pulse facilitation. Building upon the functionalities of artificial synapses, the Sn0.06Cu0.94I neuromorphic transistors simulated the fundamental pain perception function of biological nociceptors. Finally, the effects of bias stress and laser irradiation on the devices were investigated, indicating the excellent stability of the Sn0.06Cu0.94I neuromorphic transistors. Fabricated via the solution process, this low-voltage neuromorphic transistors hold significant implications for applications in bionic sensing systems and neuromorphic chip technology.

Bending Forming Characteristics of CoCrFeMnNi High-Entropy Alloy Sheets Induced by Nanosecond Pulse Laser Irradiation.

Laser bending forming, as a flexible and die-less forming approach, facilitates the three-dimensional shaping of sheets through the generation of thermal stress via laser-material interaction. In this study, the bending forming characteristics of CoCrFeMnNi high-entropy alloy sheets induced by nanosecond pulse laser irradiation were systematically investigated. The effects of parameters including laser power, scanning speed, number of scans, scanning interval, and sheet size on the bending angle, cross-sectional morphology, and hardness were studied in detail under both the laser single-line and multi-line scanning modes. The experimental results confirmed the effectiveness of nanosecond pulse laser irradiation for achieving accurate formation of CoCrFeMnNi sheets, with the successful fabrication of J, L, and U-shaped metal components. Apart from the forming ability, the cross-sectional hardness was significantly increased due to the grain refinement effect of nanosecond pulse laser irradiation. Furthermore, employing the laser single-line scanning mode enabled the effective rectification of overbending parts, showcasing complete recovery for small-angle overbending, and a remarkable 91% recovery for larger-angle overbending. This study provides an important basis for the bendability of CoCrFeMnNi sheets by laser forming and elucidates the evolution of the microstructure and mechanical properties in the bending region.

Effect of Er:YAG Laser Application and Sandblasting on Shear Bond Strength of Veneering Ceramic to Zirconia Core.

Objectives: Porcelain chipping and delamination are among the shortcomings of all-ceramic restorations. This study aimed to assess the effect of laser irradiation and sandblasting on shear bond strength (SBS) of zirconia to veneering porcelain. Materials and Methods: In this in vitro, experimental study, 60 zirconia blocks were randomly divided into three groups (n=20) for surface treatment with Er:YAG laser, sandblasting, and no surface treatment (control). Each group was randomly divided into two subgroups (n=10) for porcelain application by the layering or the pressing technique. The surface roughness, SBS, and failure mode were determined and analyzed using two-way ANOVA, Tukey's HSD test, Chi-square test, and Pearson's correlation test (alpha=0.05). Results: The mean SBS was 8.16±3.66 MPa, 9.32±2.7 MPa, and 11.85±3.06 MPa in the control, laser, and sandblasting groups, respectively. The SBS was significantly different among the three groups (P=0.002). The failure mode of the three groups was not significantly different (P>0.05). The sandblasted group showed significantly higher surface roughness than the control and laser groups (P<0.001). Conclusion: Sandblasting yielded higher SBS particularly when the porcelain was applied by the layering technique. Although laser irradiation increased the SBS, the difference with the control group was not statistically significant.