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The influence of laser polarization on the laser-induced damage threshold of fused silica is presented. Measurements were performed using femtosecond and nanosecond laser pulse durations. The impact of laser polarization on the laser damage varies with laser wavelength. While no difference in UV laser damage was observed between linear and circular polarizations, circular polarization improved the damage resistance of fused silica to infrared and visible laser radiation in comparison with linear polarization. By measuring the femtosecond laser damage of a SiO 2 thin film deposited onto a substrate, we show that the ratio between the bandgap of the sample and the photon energy causes the polarization dependent laser damage to change. These experimental findings are explained by considering the photoionization theory for solids. [ABSTRACT FROM AUTHOR]

We investigated the combinatorial synthesis and characterization of a halide perovskite CsPb(Br1−xIx)3 composition-gradient film deposited on a SrTiO3(001) substrate using infrared laser molecular beam epitaxy. In halide perovskite materials, the diffusion speed of the halogen ions is high, making it difficult to form a continuous composition-gradient film. This is because halogen ions diffuse across the entire film surface, making it impossible to specify the anion composition that changes at each position. In this study, a contact-shadow mask process was introduced to suppress the interdiffusion of halogen ions. Consequently, a CsPb(Br1−xIx)3 composition-gradient and -aligned film in which the chemical composition of CsPbBr3 and CsPbI3 changed digitally was formed and systematically characterized for the optical bandgap and photoluminescence emission wavelength with respect to the chemical composition of the halogen ion. This deposition process is expected to be promising for exploring halide perovskite materials with complex chemical compositions, such as triple-cation halide perovskites. [ABSTRACT FROM AUTHOR]

Nonlinear-optical microscopy and spectroscopy provide detailed spatial and spectroscopic contrast, specifically sensitive to structural symmetry and order. Ferroics, in particular, have been widely studied using second harmonic generation imaging, which provides detailed information on domain structures but typically lacks spectroscopic detail. In contrast, infrared-visible sum-frequency generation (SFG) spectroscopy reveals details of the atomic structure and bonding via vibrational resonances, but conventionally lacks spatial information. In this work, we combine the benefits of nonlinear optical imaging and SFG spectroscopy by employing SFG spectro-microscopy using an infrared free-electron laser. In particular, we demonstrate the feasibility of SFG spectro-microscopy for spectroscopy using in-plane anisotropic wurtzite-type aluminum nitride as a model system. We find the experimental spectra to agree well with our theoretical calculations, and we show the potential of our microscope to provide spatially resolved spectroscopic information in inhomogeneous systems such as ferroics and their domains in the near future. [ABSTRACT FROM AUTHOR]

With the increasing popularity of green fuel and the rapid growth of the marine economy, the maintenance of ship main engines, especially cylinder liners, has become a crucial issue. In this paper, we introduce a novel continuous spiral line laser scanning infrared non-destructive testing (Cslls Ir NDT) method and device for detecting scratch defects on the working surface of ship engine cylinder liners, aiming to achieve efficient and automated detection without disassembling the engine. Through numerical simulations of line laser scanning infrared NDT, we have effectively detected scratches with widths ranging from 0.05 to 1 mm and depths from 0.1 to 1.5 mm. The scanning path of the Cslls IR NDT was analysed, and the scanning images were simulated. Subsequently, the spatial reconstruction and optimisation of the scanning images were completed using pseudo-static matrix reconstruction (PSMR) and Fourier series fitting, and feature image extraction algorithms were applied to extract the feature image. Ultimately, the 3D infrared thermography visualisation of the cylinder liner was achieved through cylindrical surface mapping. The automatic detection method and device proposed in this paper provide valuable theoretical support and reference for the subsequent maintenance and repair of cylinder liners and other key tubular components. [ABSTRACT FROM AUTHOR]

As virtual reality (VR) technology advances, the use of VR scenarios and applications is becoming increasingly prevalent, and the fatigue issues associated with existing mid-air hand interactions are becoming more pronounced. To alleviate fatigue in VR interactions, we developed a desktop interaction system, BeyondDeskVR. Designed for seamless integration with mid-air hand interaction in seated VR work environments, the system enables portable interaction input and mode switching. By extending virtual hand interactions to the desktop space, the system could be used on any desktop. We utilised infrared laser projection for desktop gesture recognition and achieved seamless transitions between desktop gesture interactions and mid-air hand interactions in typical three-dimensional scenarios, including pointing and selection, user interface interaction, and object manipulation. We conducted a comprehensive evaluation of the BeyondDeskVR gesture interaction system and mid-air hand interaction using a pointing selection task, assessing their performance in terms of subjectivity, performance, and fatigue. The results indicate that the BeyondDeskVR system has high user acceptance, significantly lower fatigue than does mid-air hand interaction, and comparable interaction efficiency and accuracy. Integrating this system with mid-air hand interaction can effectively reduce fatigue in VR interactions and enhance the overall VR experience. [ABSTRACT FROM AUTHOR]

This study evaluates the corneal applicability of a refractive ultraviolet femtosecond laser in postmortal human donor eyes and ex vivo porcine eyes. Refractive lenticule extraction and flap creation were attempted in 10 human donor eyes and 80 ex vivo porcine eyes with and without abrasion of the corneal epithelium. The postmortem interval ranged from 6 to 35 h in the human samples and was set to 4, 24, and 48 h for the porcine specimens. Nine human eyes and 60 porcine eyes were treated with an ultraviolet femtosecond laser. The rest was treated with an infrared laser. Optical coherence tomography and scanning electron microscopy were used to demonstrate success or failure of the procedures. Ultraviolet laser-assisted refractive surgery attempts without prior abrasion of the corneal epithelium were only successful at 6 h p.m. in the human eyes and at 4 and 24 h in the porcine eyes. Upon epithelial abrasion, refractive surgery was always successful with the ultraviolet laser. The infrared laser always performed successfully with and without prior epithelial abrasion. Thus, postmortal changes in the corneal epithelium impair the ability of refractive ultraviolet femtosecond lasers to create stromal cuts. This progresses with time but does not affect infrared femtosecond lasers. [ABSTRACT FROM AUTHOR]

Background: Converging evidence suggests that bipolar disorder (BD) involves mitochondrial dysfunction and prefrontal cortex (PFC) hypometabolism associated with cognitive impairment, which persists in remitted BD individuals. Transcranial infrared laser stimulation (TILS) provides safe, non-invasive brain stimulation that enhances PFC metabolism via photobiomodulation of mitochondrial respiration and tissue oxygenation. We tested the hypothesis that the neurocognitive deficits found in BD may be ameliorated by TILS treatments. Methods: This is the first study to explore neurocognitive effects of repeated TILS administration in BD. Using an open-label design, 29 individuals with remitted BD received six weekly TILS treatments. Working memory and attention were assessed with trail-making and 2-back tasks sensitive to TILS cognitive effects in individuals with BD. Changes in PFC network interactions were measured with functional near-infrared spectroscopy (fNIRS) because this method can measure TILS effects on oxygen metabolism in the PFC of individuals with BD. Results: Participants reported no adverse effects from treatment, confirming the safety of this intervention in individuals with BD. Cognitive test results showed that in people with remitted BD, TILS was effective at improving cognition, i.e., enhanced speed and accuracy in tasks reflecting cognitive flexibility, working memory, and attentional control. Antipsychotic medication improved TILS cognitive effects. The fNIRS results showed a significant reduction in PFC network correlations of oxygenated hemoglobin changes driven by cognitive task performance. The right-hemisphere frontopolar cortex showed greater TILS effects than its left-hemisphere counterpart. Conclusions: Repeated TILS is a safe intervention to improve cognition in people with remitted BD. Continued antipsychotic medication may have contributed to the cognitive improvement. To confirm TILS efficacy, a sham-controlled, double-blinded randomized trial is needed. Clinical trial registration: https://clinicaltrials.gov/ , identifier NCT05354895. [ABSTRACT FROM AUTHOR]

The laser periodic heating method is widely used to measure the thermal diffusivity of various thin films. In this technique, surface temperature responses are monitored using either an infrared (IR) camera or a thermocouple (TC) detector. Under air pressure, the impact of air heat loss on these two measurement methods warrants further examination. In this study, we measured the in-plane thermal diffusivity of a polyethylene terephthalate (PET) film under air pressure using both a non-research-grade IR camera and a microscale TC. Results indicate that air heat loss significantly influenced the TC measurements, yielding an abnormally high thermal diffusivity. Comparatively, the thermal diffusivity measured by the IR camera decreased slightly as modulation frequency increased from 0.1 Hz to 1 Hz. When the thermal diffusion length was approximately three times the film thickness, the diffusivity values from the IR camera closely matched those obtained under vacuum, indicating that the non-contact IR method can effectively suppress the impact of air heat loss. [ABSTRACT FROM AUTHOR]

BACKGROUND: Precision therapy based on multifunctional nanomaterials is a novel therapeutic model for malignancies that can integrate multiple imaging and therapeutic models into one nanoscale platform to achieve visual combination treatment. OBJECTIVE: To prepare novel nanoparticles loaded with Cu2(OH)PO4 nanoparticles (CuNPs) and nuciferine (NF) (h-PCuNF), and to explore their ability to mediate combined photothermal therapy/photodynamic therapy/chemodynamic therapy/chemotherapy for malignancy. METHODS: The h-PCuNF nanoparticles were synthesized through a double-emulsion procedure, through which the CuNPs and NF were loaded into the shell of hollow poly(lactic-co-glycolic) acid nanocarriers. The morphology, structure, particle size, and zeta potential of the h-PCuNF nanoparticles were characterized. In deionized water, the magnetic resonance imaging and photothermal conversion performances of the h-PCuNF nanoparticles, as well as their capability to implement reactive oxygen species production by mediating photocatalysis and Fenton-like reactions, were evaluated. In liver malignant tumor cell line HepG2 cells, the effectiveness of the photothermal therapy/photodynamic therapy/chemodynamic therapy/chemotherapy combination therapy mediated by the nanoparticles was detected by employing fluorescence imaging and MTT assay. RESULTS AND CONCLUSION: (1) The h-PCuNF nanoparticles possessed a hollow spherical structure in which the CuNPs (drug loading rate and encapsulation rate were 26.3% and 63.2%, respectively) and NF (drug loading rate and encapsulation rate were 11.0% and 52.6%, respectively) were loaded into the shell. The average particle size of the h-PCuNF nanoparticles was (309.2±10.0) nm, while the zeta potential was determined to be (-12.5±0.9) mV. In physiological environments, the nanoparticles possess favorable suspension stability. (2) In deionized water, the h-PCuNF nanoparticles could markedly enhance T1-weighted magnetic resonance imaging images. The h-PCuNF nanoparticles showed remarkable photothermal conversion and photocatalytic reactive oxygen species generation capabilities under near infrared laser irradiation. In addition, the h-PCuNF nanoparticles could consume glutathione and mediate Fenton-like reactions to produce OH. (3) The h-PCuNF nanoparticles could be taken up by HepG2 tumor cells and were mainly distributed in the cytoplasm. The synergistic therapeutic effect was demonstrated after the nanoparticles were activated by near infrared laser irradiation, because CuNPs mediated photothermal therapy/ photodynamic therapy/chemodynamic therapy and NF mediated chemotherapy could synergistically eliminate the tumor cells. [ABSTRACT FROM AUTHOR]

In this work, a highly sensitive, selective, and industrially compatible gas sensor prototype is presented. The sensor utilizes three distributed-feedback quantum cascade lasers (DFB-QCLs), employing wavelength modulation spectroscopy (WMS) for the detection of hydrogen sulfide (H2S), methane (CH4), methyl mercaptan (CH3SH), and carbonyl sulfide (COS) in the spectral regions of 8.0 µm, 7.5 µm, and 4.9 µm, respectively. In addition, field-programmable gate array (FPGA) hardware is used for real-time signal generation, laser driving, signal processing, and handling industrial communication protocols. To comply with on-site safety standards, the QCL sensor prototype is housed in an industrial-grade enclosure and equipped with the necessary safety features to ensure certified operation under ATEX/IECEx regulations for hazardous and explosive environments. The system integrates an automated gas sampling and conditioning module, alongside a purge and pressurization system, with intrinsic safety electronic components, thereby enabling reliable explosion prevention and malfunction protection. Detection limits of approximately 0.3 ppmv for H2S, 60 ppbv for CH3SH, and 5 ppbv for COS are demonstrated. Noise-equivalent absorption sensitivity (NEAS) levels for H2S, CH3SH, and COS were determined to be 5.93 × 10−9, 4.65 × 10−9, and 5.24 × 10−10 cm−1 Hz−1/2. The suitability of the sensor prototype for simultaneous sulfur species monitoring is demonstrated in process streams of a hydrodesulphurization (HDS) and fluid catalytic cracking (FCC) unit at the project's industrial partner, OMV AG. [ABSTRACT FROM AUTHOR]

The extraction of bio-compounds from medicinal plants provides opportunities for using the plant extract for health benefits. Rosa canina L. is considered a "natural superfood", and the valorization of its active compounds requires an extraction technique that ensures a suitable extraction yield while preserving the compounds' activity. In our study, infrared laser irradiation (IRLIR) technology was used for the first time in the bioactive compound's extraction from Rosa canina L. Different solvents (water–ethanol, hexane–ethanol) and different extraction times were tested to obtain a high extraction yield. Chromatographic and spectrophotometry methods were used to monitor the profile of bioactive compounds and the antioxidant activity of the extracts. The results obtained for IRLIR were compared with those obtained by accelerated solvent extraction (ASE), an advanced extraction method. The IRLIR technology proved to be a more reliable analytical tool for the extraction of (+)-catechin, gallic acid, and lutein. In addition, a richer extract formula was obtained by IRLIR extraction with respect to ASE, with the IRLIR process ensuring a short extraction time, low volume of the extraction solvent, low energy consumption, and a less expensive device. [ABSTRACT FROM AUTHOR]

Investigate the impact of antimicrobial photodynamic therapy (aPDT) using different photosensitizers (PSs) such as indocyanine green (IG), curcumin (CC), and methylene blue (MB), with or without intracanal application of calcium hydroxide (CH), on the push-out bond strength of glass-fiber posts (GFPs) to intraradicular dentin, the chemical composition of the root substrate, and the sealing of the adhesive interface across different thirds of intraradicular dentin. A total of 112 bovine teeth underwent biomechanical preparation and were divided into eight experimental groups (n = 14 each): Negative control with deionized water; positive control with deionized water + CH; IG group with indocyanine green and infrared laser; IG + CH group; CC group with curcumin and blue LED; CC + CH group; MB group with methylene blue and red laser; and MB + CH group. The push-out bond strength was measured using a universal testing machine (n = 8), and scanning electron microscopy characterized the fracture patterns. Energy dispersive spectroscopy (n = 3) analyzed the chemical composition of the dentin substrate, while fluorescence confocal microscopy (n = 3) assessed the adhesive interface sealing between the resin cement and root dentin. Data were analyzed using two-way repeated measures ANOVA and the Tukey test for push-out bond strength and chemical composition comparison, with the Kruskal-Wallis and Dunn's tests (α = 0.05) for adhesive interface sealing. Significant bond strength differences were noted across root thirds and experimental groups (P <.05), with the IG + CH group showing the highest cervical bond strength and the IG group the lowest. Apical bond strength was highest in the CC group but lower in the NC and PC groups. Mixed failures predominated, except in the MB + CH group, where adhesive failures prevailed. Elemental composition varied among groups treated with different PSs and CH (P <.05), but interface quality, tag formation, and penetration depth showed no significant differences (P >.05). Laser-activated 500 mg/L CC combined with CH emerged as a clinically relevant option for root canal decontamination before GFPs luting. aPDT with different PSs and root canal depth influenced the push-out bond strength of GFPs and the chemical composition of root dentin. Curcumin-mediated aPDT at 500 mg/L proved effective, enhancing bond strength and sealing while maintaining consistent dentin composition across depths. [ABSTRACT FROM AUTHOR]

To achieve non-destructive detection of crack depth in the process of notching and cracking of metal bars in low-stress cropping, a quantitative detection method for crack depth of notched bars based on infrared thermography technology under laser excitation is proposed in this paper. Combined with physical experiments, a simulation model of the temperature distribution of the laser-excited bar is established for efficient data acquisition, and the temperature curves of the bar surface under laser excitation are analysed from the perspective of space and time. On this basis, the study selects the feature parameters of the three types of defects on the surface of the metal bar, namely notch, surface crack and crack of notch bottom. A backpropagation (BP) neural network model is established for crack depth by dividing the crack into two types of a notch with crack and unnotched crack, and compared with other common prediction models. The results show that the selected features can accurately characterise the cracks in this BP neural network model, and the detected error in crack depth assessment is less than 3%. Performance metrics are established to evaluate the model, which has good reliability under different noises. [ABSTRACT FROM AUTHOR]

[Display omitted] • PP face masks can be recovered as 67 wt% PP wax through laser flash pyrolysis. • Pyrolysis wax with an average number of terminal double bonds of 1.55. • The PP-based compatibilizer improves the tensile strength of PLA/PP blends by 29 %. During the COVID-19 pandemic, face masks, as personal protective equipment (PPE) against the coronavirus (SARS-CoV-2), have been widely used worldwide. How to properly dispose of used PPE has brought a huge challenge to the ecosystem and human health. Here we proposed a laser flash pyrolysis (LFP) strategy to upcycle the used polypropylene(PP) face mask to vinylidene-terminated PP wax (PP-VDT) and further functionalized for compatibilizer application. Carbon black (0.2 wt%) was mixed with masks as a light absorbent to improve photothermal conversion efficiency. An infrared laser was adopted as the thermal source to quickly depolymerize the used PP face mask within just several milliseconds. The pyrolysis fragments quickly vaporized out to form PP-VDT with high selectivity (average terminal vinylidene per molecular chain was up to 1.55). The PP-VDT appeared as white solid particles which were clean and high purity. In addition, PP-VDT as polymer precursors could be further functionalized by thiol-ene chemistry to hydroxyl-terminated PP (PP-OH) and isocyanate-terminated PP (PP-HMDI), which could be used as compatibilizer in PLA/PP blends to decrease the size of the dispersed PP phase and to improve tensile strength. Therefore, this LFP technique was an effective upcycling method for PP face masks to obtain value-added products. [ABSTRACT FROM AUTHOR]

In laser safety eyewear, due to the lack of complete blocking of ultraviolet and infrared rays, we proposed a structure based on one-dimensional multilayer composed of several layers of silicon dioxide and zirconium dioxide materials alternately behind polycarbonate lens. It is find out that the acceptance angle range to the photonic crystal is 0 to 39°. This incident angle range corresponds to the band gap of the photonic crystal. In the transverse electric polarization, with increasing incident angle, the width of the gap rises, while in the transverse magnetic polarization decreases. Our results show that in the transverse electric mode, the optical density gradually increases with increasing angle while it decreases in the transverse magnetic one. The higher optical density, the higher eye protection at specified wavelength. If the incident wavelength is placed in the band gap region, the field intensity gradually decays. Therefore, the proposed structure for laser safety eyewear can provide the maximum reflection on the surface of the lens. Our supposed structure for safety eyewear can be used in infrared lasers. [ABSTRACT FROM AUTHOR]

Carbon fiber reinforced polymers (CFRPs) are widely used in fields such as aviation and aerospace. However, subtle defects can significantly impact the material's service life, making defect detection a critical priority. In this paper, delamination defects in CFRP are detected using line laser infrared thermography, and a defect characterization algorithm that combines differential thermography with a frequency-domain filter is proposed. This approach effectively eliminates the trailing phenomenon caused by line laser scanning and produces defect feature images with a higher signal-to-noise ratio. The size of the processed defects is then measured using pixel deviation values combined with K-means edge detection. The results show that the measured dimensions of defects are larger than the actual dimensions at the initial stage of cooling after excitation and smaller than the actual dimensions at the end of the cooling phase. The maximum measurement error for defect size was 2.74 mm2 throughout the measurement interval. In addition, defect depth evaluation was achieved by fitting the curve of defect depth against the peak value in the frequency domain, with the resultant R-square value were all higher than 0.9877. This confirms the validity and accuracy of the methodology used in this study. [ABSTRACT FROM AUTHOR]

Quantitative mass spectrometry imaging (qMSI) provides the relative or absolute analyte quantities in a biological specimen in a spatially resolved manner. However, the chemical complexity and physical structure of biological specimens often require one to precisely account for matrix effects in qMSI platforms. Infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) completely ablates a volume of cryosectioned tissue. This enables the use of a normalization standard that is sprayed underneath the tissue for qMSI applications. Complete sampling has shown to be a significant advantage for qMSI by IR-MALDESI; however, the impact of high tissue heterogeneity has not been systematically studied or quantified. The bias introduced by tissue heterogeneity was investigated by uniformly spraying standards beneath and on top of a whole-body zebrafish section. The quantitative relationship between the signals of the two standards was investigated across this multi-organ model to serve future qMSI experiments by IR-MALDESI and other laser ablation–based sampling methods. The overall ratio between the standards sprayed on top of and beneath the tissue sections remained constant across the entire whole-body section despite significant tissue heterogeneity (e.g., gills, heart, and liver). Additionally, we noted that thinner and/or sucrose-embedded tissues improved these ratios, which will inform future qMSI investigations. [ABSTRACT FROM AUTHOR]

The focus of this research is to use the thermal ablation properties of a Nd:YAG infrared laser to highlight the thermal damage caused by the extinction of the plasma, which leads to the disappearance of the spectra of certain polymers as the laser energy increases. The study involved testing five commonly used polymers: polytetrafluoroethylene (PTFE) also known as Teflon, polyoxymethylene (POM), polyvinyl chloride (PVC), Bakelite, and polyamide. Laser induced breakdown spectroscopy (LIBS) analysis was used to qualitatively analyze the plasma generated from the polymer samples, identifying the excited species present in each of the five polymers. Wavelength dispersive X‐ray fluorescence (WDXRF) analysis of the polymer samples further confirmed the identification of these excited species. The results obtained from the spectra recorded at different laser energies in an air environment showed that the saturation observed in the plasma, induced by increasing laser energy, is not consistently observed for all polymers. This plasma extinction phenomenon in certain polymers is attributed to thermal effects when using an infrared (IR) laser as a heating source. [ABSTRACT FROM AUTHOR]

Ammonium dinitramide (ADN) is a new green oxidant, which is a kind of high-energy ionic liquid and has been widely used in the field of liquid propulsion. When it is used in laser plasma propulsion, its poor absorption coefficient significantly limits its application. To address the issue, this paper investigates the effects of the content of the infrared dye and the laser energy density on the laser propulsion performance of an ADN-based liquid propellant. The performance of the liquid propellant was tested by the light absorption performance test system and the micro-impulse test system. The results show that the addition of infrared dye can significantly improve the light absorption performance of the liquid matrix. As the content of the infrared (IR) dyes increases from 0.3 wt.% to 0.6 wt.%, the absorption coefficient of the ADN-based liquid propellant increases from 248.84 cm−1 to 463.85 cm−1, and the absorption depth decreases from 40.20 μm to 21.56 μm. At a laser energy density of 21.60 J·cm−1, when the IR dye content increases from 0.3 wt.% to 0.6 wt.%, the specific impulse increases from 26.43 s to 54.43 s and the ablation efficiency increases from 4.32% to 18.21%. Significantly luminous plasma appears in the ablation plume at higher laser energy densities, accompanied by higher-velocity plasma shock waves. Compared to the factor of the infrared dye content, the laser energy density contributes more to the ablation efficiency, especially when the increase in laser energy density promotes the full release of chemical energy from the liquid propellant, which, in turn, also enhances the impulse, impulse coupling coefficient, and the plasma detonation velocity. The results provide an important reference for the design of an energy-containing liquid propellant. [ABSTRACT FROM AUTHOR]

Group 14/16 adamantane‐type hybrid clusters of the type [(RT)4E6] (T=group 14 element, E=group 16 element, R=organic group) have been reported to emit white‐light when irradiated in an amorphous state with a continuous‐wave (CW) infrared laser diode. This effect is enhanced if the cluster core is varied from a binary to a more complex composition. To further explore this phenomenon, we synthesized clusters with a multinary R/R'‐T/T'‐E/E' composition, including isolobal replacement of E with CH2, in [(2‐NpSi){CH2Sn(S)Ph}3] (1, Np=naphthyl). When expanding one of the CH2 moieties to a C2H4 group, thus generating a R/R'‐T/T'‐E/E'/E" cluster composition, we unexpectedly observed a dimerization of the initially formed, yet non‐isolable adamantane‐like cluster [(2‐NpSi){CH2Sn(S)Ph}2{C2H4Sn(S)Ph}] (2) to [(2‐NpSi){CH2Sn(S)Ph}2{C2H4Sn(S)Ph}]2 (3), exhibiting a heretofore unprecedented cluster architecture. Both monomeric 1 and dimeric 3, show white‐light emission as thin films. The nonlinear optical response of the compounds was also modelled with DFT methods. [ABSTRACT FROM AUTHOR]

This study aimed to assess the impact of nutritional conditions and irradiation parameters on the viability and proliferation of murine preosteoblasts. MC3T3-E1 cells were maintained under standard culture conditions (αMEM supplemented with 10% fetal bovine serum) or nutritional deficit conditions (αMEM without serum) and irradiated or not (control) with an InGaAlP diode laser at wavelengths of 660 nm (red) or 790 nm (infrared), with doses of 1, 4, or 6 J/cm², in a single dose in continuous mode. Cell viability and proliferation were assessed 24, 48, and 72 h after irradiation using the Alamar blue reduction assay. The cell cycle and events related to cell death were evaluated via propidium iodide (PI) staining and Annexin V/PI assays, respectively, through flow cytometry. The data revealed that in cells cultured with normal nutrition (10% FBS), there was no significant difference (p > 0.05) in cell viability or proliferation among the different irradiation protocols. In contrast, in the experiments conducted under nutritional deficiency, the infrared laser at a dose of 6 J/cm² significantly increased (p < 0.05) cell viability and proliferation compared with those of the control group at 72 h. The data were confirmed by cell cycle and cell death events (Annexin V/PI) assays. These results suggest that in vitro PBM yields more consistent biostimulatory effects on pre-osteoblasts subjected to nutritional deficiency, highlighting the need for attention to simulate these conditions in studies with laser therapy in in vitro bone disease models and in in vitro experiments using PBM for bone tissue engineering. [ABSTRACT FROM AUTHOR]

In peanut cultivation, the fact that the fruits develop underground presents significant challenges for mechanized harvesting, leading to high loss rates, with values that can exceed 30% of the total production. Since the harvest is conducted indirectly in two stages, losses are higher during the digging/inverter stage than the collection stage. During the digging process, losses account for about 60% to 70% of total losses, and this operation directly influences the losses during the collection stage. Experimental studies in production fields indicate a strong correlation between losses and the height of the windrow formed after the digging/inversion process, with a positive correlation coefficient of 98.4%. In response to this high correlation, this article presents a system for estimating the windrow profile during mechanized peanut harvesting, allowing for the measurement of crucial characteristics such as the height, width and shape of the windrow, among others. The device uses an infrared laser beam projected onto the ground. The laser projection is captured by a camera strategically positioned above the analyzed area, and through advanced image processing techniques using triangulation, it is possible to measure the windrow profile at sampled points during a real experiment under direct sunlight. The technical literature does not mention any system with these specific characteristics utilizing the techniques described in this article. A comparison between the results obtained with the proposed system and those obtained with a manual profilometer showed a root mean square error of only 28 mm. The proposed system demonstrates significantly greater precision and operates without direct contact with the soil, making it suitable for dynamic implementation in a control mesh for a digging/inversion device in mechanized peanut harvesting and, with minimal adaptations, in other crops, such as beans and potatoes. [ABSTRACT FROM AUTHOR]

Iron (Fe)‐based nanoparticles (NPs) have attracted considerable attention in nanomedicine research due to their enhancement effects in magnetic resonance imaging (MRI) and cancer therapy. Although zero‐valent Fe (Fe(0)) can serve as an active catalyst to decompose H2O2 into reactive oxygen species (ROS), its activity is compromised in physiological conditions due to its susceptibility to oxidation. Here it is reported that a 9 nm FeAu alloy NP system can efficiently stabilize Fe(0) in neutral pH solution, but release Fe(0) in tumor‐bearing environment, catalyzing H2O2 decomposition to ROS. Although Fe3O4 NPs and Au NPs are well‐known for their biocompatible, FeAu NPs effectively eliminate cancer cells at an IC50 as low as 15 µg mL−1 Fe. Further proteomics analysis reveals that FeAu NPs can concomitantly induce both ferroptosis and pyroptosis. Additional near‐infrared (NIR) irradiation further increases cell death and promotes maturation of dendritic cells within tumor‐draining lymph nodes and infiltration of helper T cells and cytotoxic T lymphocytes within tumor sites, resulting in significant reduction in tumor growth and metastasis. The studies demonstrate a great potential of FeAu NPs as a stable Fe(0) reservoir for pH/NIR controlled Fe(0) release and further for ferroptosis and pyroptosis co‐mediated tumor immunotherapy. [ABSTRACT FROM AUTHOR]

Among pet species, mammary tumors are most commonly encountered in dogs. In the traditional treatment of mammary tumors in dogs; surgical operation, chemotherapy, immunotherapy, cryotherapy, radiotherapy and homeopathy are used. Herein, we reported vincristine loaded nano graphene oxide (Vin@nGO) for simultaneous photothermal therapy (PTT) and chemotherapy under near infrared laser (NIR, 808 nm), whereas GO was used both as a platform for vincristine and as a photothermal (PT) agent, and vincristine was used as a chemotherapeutic agent. Spontaneous mammary tumor masses of a dog were removed and primary tumor cells were obtained and propagated by tissue culture from tumor tissue samples under appropriate conditions. Then, these cells were incubated with Vin@nGO and exposed to NIR laser. NIR laser irradiation at 808 nm was converted to heat by nGO, then the target cancer cells were destroyed by both hyperthermia and chemotherapy. MTS analysis was performed to test the effectiveness of this dual therapy on cell proliferation and a statistically significant (p < 0.05) decrease in cell proliferation/viability was found (90% reduction compared to the control group (p < 0.0001)). Our study data also shed light on usability of Vin@nGO in the in vivo model for future work. [ABSTRACT FROM AUTHOR]

A new gas analytical technique for infrared laser spectroscopy combined with differential pressure measurement (IR-DP) is developed. The basic idea of this technique is that the absorption process of molecules by laser irradiation is monitored as the pressure enhancement in a gas cell by use of a differential pressure gauge. The system is composed of a tunable IR laser system, sample cell, differential pressure gauge, and data accumulation system. Using this system, the measurements of the IR absorption spectra for cyclohexane (50 ppm) and ammonia (100 ppm) are demonstrated. By comparison of the current IR-DP spectra with conventional Fourier-transform infrared spectra, the spectral resolution is found to be about 3 cm−1, reflecting the laser resolution. Furthermore, the estimated pressure enhancement based on a simple model is consistent with the experimental results. These results suggest that the newly developed IR-DP technique is one of a powerful tool for trace gas detection. [ABSTRACT FROM AUTHOR]

This article presents research on advanced surface preparation methods for sintered carbides (WC-Co, grade B2) commonly used in the tool industry, particularly in the context of bonding these materials with C45 steel using adhesives. Sintered carbides are widely used due to their high hardness, wear resistance, and good ductility, making them ideal for manufacturing tools operating in harsh conditions. Traditional bonding methods, such as brazing and welding, often result in stresses and cracks. Adhesive bonding has therefore emerged as an effective alternative to mitigate these challenges. The research focuses on comparing the results obtained through modern surface treatment techniques, such as laser micro-texturing and plasma treatment, with traditional methods like grinding, abrasive blasting, and electrolytic etching. The influence of these methods on adhesion properties and the strength of adhesive bonds was evaluated through mechanical tests, including static shear and pull-off tests. An approximately 50% increase in the mechanical strength of adhesive joints was observed for surfaces treated with low-temperature plasma (operating voltage: 18 kV, flow of gasses: 20 l/min., treatment time: 60 s) and laser micro-texturing (infrared fiber laser, wavelength: 1064 nm (±5 nm), power: 20 W), as compared to mechanical grinding. The shear strength of the adhesive joints was equal to 32 MPa and 30 MPa on average in the case of treatment with low-temperature plasma made of helium and argon, respectively. The highest strength of an adhesive joint was equal to 34.5 MPa on average in the case of laser micro-texturing. [ABSTRACT FROM AUTHOR]

Volume nanogratings (NGs) imprinted by infrared femtosecond laser in commercial optical glasses take the form of orientable subwavelength birefringent nanostructures, being composed of an assembly of nanopores. The existence of NGs strongly depends on the laser parameters and glass composition. Therefore, in this work, we tentatively model the erasure threshold of NGs in a pulse energy - repetition rate processing window. For this purpose, we combine i) a heat diffusion model to simulate the thermal treatment experienced by the glass upon laser irradiation, and ii) the Rayleigh-Plesset equation to take into account the evolution of a nanopore size during laser processing. We first determine a criterion for nanopores erasure, falling within a typical characteristic time of few tens of ns, for which the cooling of the last laser pulse absorbed by the material is progressively cooled. Then, considering a multipulse regime, and the dependence of the deposited pulse number on the thermal treatment experienced by the glass, the modeled NGs erasure threshold follows the experimental trend. Finally, by using a steady state regime for various repetition rates and adjusting the energy deposition (absorption coefficient or beam waist) as a function of the pulse energy, the NGs existence window can perfectly match the experimental values. [ABSTRACT FROM AUTHOR]

Thermal heating of biological samples allows to reversibly manipulate cellular processes with high temporal and spatial resolution. Manifold heating techniques in combination with live‐cell imaging were developed, commonly tailored to customized applications. They include Peltier elements and microfluidics for homogenous sample heating as well as infrared lasers and radiation absorption by nanostructures for spot heating. A prerequisite of all techniques is that the induced temperature changes are measured precisely which can be the main challenge considering subcellular structures or multicellular organisms as target regions. This article discusses heating and temperature sensing techniques for live‐cell imaging, leading to future applications in cell biology. [ABSTRACT FROM AUTHOR]

Nanoparticle-based photo-immunotherapy has become an attractive strategy to eliminate tumors and activate host immune responses. However, the therapeutic efficacy is heavily restricted by low tumoral penetration and immunosuppressive tumor microenvironment (TME). Herein, near infrared laser (NIR)-propelled Janus nanomotors were presented for deep tumoral penetration, photothermal tumor ablation and photothermal-triggered augmented immunotherapy. The Janus nanomotors (AuNR/PMO@CPG) were constructed with gold nanorods (AuNR) and periodic mesoporous organo-silica nanospheres (PMO), followed by loading of immune adjuvant (CPG ODNs). Under NIR irradiation, the nanomotors exhibited superior photothermal effect, which produced active motion with a speed of 19.3 µm/s for deep tumor penetration and accumulation in vivo. Moreover, the good photothermal heating also benefited effective photothermal ablation to trigger immunogenic cell death (ICD). Subsequently, the ICD effect promoted the release of tumor-associated antigens (TAAs) and damage associated molecular patterns (DAMPs), and further generated abundant tumor vaccines in situ for reprograming the immunosuppressive TME in combination with CPG ODNs to inhibit tumor growth. As a result, a notable in vivo synergistic therapeutic effect was realized on CT26-bearing mice by combining photothermal therapy-induced ICD with modulation of immunosuppressive TME. Thus, we believe that the synthesized nanomotors can provide a new inspect to boost photothermal therapy-induced ICD in tumor immunotherapy. Nanoparticle-based synergistic photo-immunotherapy has become a popular strategy to eliminate tumors and activate host immune responses. However, the therapeutic efficacy is heavily restricted by low tumoral penetration and immunosuppressive tumor microenvironment (TME). In this work, near infrared laser (NIR)-propelled Janus nanomotors were presented for deep tumoral penetration, photothermal tumor ablation and photothermal-triggered augmented immunotherapy. Under NIR irradiation, the nanomotors exhibited a superior photothermal effect, which produced active motion for deep tumor penetration and accumulation in vivo. Moreover, good photothermal heating also facilitated effective photothermal ablation to trigger immunogenic cell death (ICD), which promoted the release of tumor-associated antigens and damage-associated molecular patterns (DAMPs), and further generated abundant tumor vaccines in situ for reprograming the immunosuppressive TME to inhibit tumor growth. [Display omitted] [ABSTRACT FROM AUTHOR]

Periodontitis, an oral disease initiated by a dysbiotic dental biofilm, has an unclear response to photobiomodulation (PBM) as an adjunctive treatment. This study investigates the effects of PBM on reactive oxygen species (ROS), apoptosis, oxidative stress, and inflammatory markers in a periodontitis model using C57BL/6 mice, divided into four groups: control (C), control + PBM (C + PBM), periodontitis (P), and periodontitis + PBM (P + PBM). An infrared diode laser (808 nm, 133.3 J/cm2, 4 J/session) was applied for three days. PBM reduced superoxide anions, hydrogen peroxide, and apoptosis in gingival cells, while decreasing systemic inflammation and protein oxidation. In the P + PBM group, pro-inflammatory cytokines IL-6 and IL-12p70 decreased, whereas IL-10 increased, suggesting improvements in oxidative stress and inflammation profiles. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) is a layerwise production process that creates three-dimensional objects according to a digital model. This technology has demonstrated to be a promising alternative to conventional manufacturing methods for various industrial sectors, such as aerospace, automotive, biomedical, and energy. AM offers several advantages, like design flexibility, material efficiency, functional integration, and rapid prototyping. As regards metal parts, conventional AM techniques using infrared laser sources face some limitations in processing high-reflectivity and high-conductivity materials or alloys, such as aluminum, copper, gold, and silver. These materials have low absorption of infrared radiation, which results in unstable and shallow melt pools, poor surface quality, and high porosity. To overcome these challenges, green and blue laser sources have been proposed for AM processes. This review provides an overview of the recent developments and applications of green and blue laser sources for powder bed fusion of copper and its alloys, focusing on the effects of process parameters on the melt pool dynamics, microstructure formation, and thermal and electrical properties of the fabricated parts. This review also presents the main applications of AM of copper and its alloys together with potential opportunities for future developments. [ABSTRACT FROM AUTHOR]

This study evaluated the influence of infrared laser radiation produced by a CO2 laser, performing under different engraving parameters, on the colour changes and chemical composition of a beech wood surface. The results showed that the lightness clearly decreased with increasing laser power and density. At the highest laser power and the highest raster density, the ΔL* value was 51.3. The values of coordinates a* and b* moderately increased up to a raster density of 5 mm−1; then, with a subsequent raster density increase, the values of these coordinates decreased again. However, the coordinate values were positive in all cases. Even the lowest laser power and raster density resulted in conspicuous discolouration or even a completely new colour compared to the original (ΔE = 10) of the beech wood surface. Further increases in the laser power and raster density resulted in progressively pronounced colour differences and a darker brown colour of the surface. The ATR-FTIR chemical analysis of the beech wood surface revealed that discolouration was mainly caused by heat-induced processes associated with the degradation of carbonyl groups (C=O) in lignin and hemicelluloses. The splitting of C=O bonds induced changes in the content of chromophores responsible for the natural wood colour and for the engraving-related discolouration. The study demonstrates that the amount of energy supplied onto the wood surface by a laser beam using diverse combinations of radiation parameters can be represented by a single variable: the total irradiation dose. The functional relation detected between this variable and the colour differences may serve as a basis for using a controlled laser beam for targeted wood surface discolouration to improve the quality of patterns transferred onto a wood surface. Knowledge of this relation will enable the targeted setting of the laser parameters during engraving so that the laser beam can be used as a tool for transferring high-quality patterns onto wood surfaces. [ABSTRACT FROM AUTHOR]

Vanadium dioxide (VO2), renowned for its reversible metal‐to‐insulator transition (MIT), has been widely used in configurable photonic and electronic devices. Precisely tailoring the MIT of VO2 on micro‐/nano‐scale is crucial for miniaturized and integrated devices. However, existing tailoring techniques like scanning probe microscopy, despite their precision, fall short in efficiency and adaptability, particularly on complex or curved surfaces. Herein, this work achieves the local engineering of the phase of VO2 films in high efficiency by employing laser writing to assist in the hydrogen doping or dedoping process. The laser doping and laser dedoping technique is also highly flexible, enabling the fabrication of reconfigurable, non‐volatile, and multifunctional VO2 devices. This approach establishes a new paradigm for creating reconfigurable micro/nanophotonic and micro/nanoelectronic devices. [ABSTRACT FROM AUTHOR]

This paper is devoted to the experimental study of the characteristics of a continuous optical discharge (COD) sustained by high power continuous wave laser radiation at a wavelength λ = 1.08 μ m in high pressure argon. New data on the COD threshold laser power dependence of argon pressure in the range 20–50 bar is obtained. The COD threshold laser power is shown to be in good agreement with the data obtained by other authors and theoretical evaluations provided the contribution of plasma energy loss due to thermal radiation is taken into account properly. The maximum plasma temperature was estimated to be 20–21 kk or higher, favorable to obtain high UV spectral radiance. A study of the convective plume oscillations around COD in argon has been carried out. It is found that in the pressure range 25–35 bars the growth of the laser radiation power leads to a decrease in convection oscillation frequency from 33 to 29 Hz, while the radius of the convective plume grows accordingly. The oscillation frequency ν and characteristic radius of the convective plume r 0 were found to obey the similarity relation ν = 0.5 g / 2 r 0 previously established in experiments with COD in xenon. These results are promising for using COD in argon as a high brightness broadband UV radiation source. [ABSTRACT FROM AUTHOR]

Deferred diabetic skin healing is an ever‐growing complication owing to the hyperglycemic microenvironment, which accelerates the generation of advanced glycated end products (AGEs) and provides a hotbed for pathogenic infection. Here, the H2S‐evolving bio‐heterojunction enzyme (BioHJzyme), which is consisted by MXene/FeS2 and glucose oxidase (GOx) is devised. It presents glutathione peroxidase (GPx)‐ and peroxidase (POD)‐mimetic antibacterial activity for anti‐pathogens and wound regeneration by AGEs depression. The GOx catalyzes glucose, resulting in reducing the bacterial nutrient and supplying H2O2. The POD‐mimetic activity of the BioHJzyme catalyzes the H2O2 to hydroxyl radical (•OH) with a turnover number of 4.45 × 10−1 s−1, while the GPx‐mimetic activity of it consumes glutathione for further •OH accumulation. The anti‐pathogens can be enhanced by near infrared laser (NIR) irradiation owing to the efficient separation of electron‐hole pairs originated from the heterostructure, which presents NIR‐activatable •OH and 1O2 production. Moreover, the BioHJzyme evolves H2S in acidic environment, acting as an H2S donor, which protects cells around the wound from oxidative damage and AGEs, rescues mitochondrial respiration, improves the extracellular matrix deposition and ameliorates dysfunction of fibroblasts for diabetic skin regeneration through TGF‐β/Smad pathway. The work provides a proof‐of‐concept for bacteria‐invaded diabetic wound regeneration via H2S‐evolving BioHJzyme. [ABSTRACT FROM AUTHOR]

In this work, we report a long-wave infrared (LWIR) modulator based on the two-photon absorption of CO2 gas. The effect of gas pressure and laser power on the modulation under different wavelengths is discussed. A maximum modulation depth of 21.5% with a rise time (full time) less than 20 ns for a 9.36 μm laser was achieved. The gaseous modulator, which adopts a 2.75 μm laser as the pumping source, is capable of converting the pulse characteristics of the pump light into the modulation of the long-wave infrared light. It demonstrates promising potential for applications in the rapid optical modulation of LWIR lasers. [ABSTRACT FROM AUTHOR]

Emissions standards describe the fuels, the procedures, and, among others, the analyzers to be used for the measurement of the different compounds during the type-approval of heavy-duty engines and vehicles. Traditionally, NOx, CO, hydrocarbons, and CO2 were the gaseous compounds measured within the Euro standard, with the later addition of CH4 and NH3. Euro 7, introduced in early 2024, expanded those compounds, requiring the measurement of N2O and HCHO. With an increasing number of molecules that need to be measured and introducing carbonless fuels, such as hydrogen, that present different requirements compared to carbon-based fuels, the test procedure needs to be updated. The performances of three laboratory-grade instruments and three portable emissions measurement systems based on Fourier-transformed infrared (FTIR) or quantum cascade laser infrared (QCL-IR) technologies were investigated while measuring from the tailpipe of a Diesel engine and a compressed natural gas (CNG) vehicle. All instruments presented good agreement when emissions of NOx, CO, CH4, NH3, N2O, HCHO, and CO2 were compared using: Z-score, F-test and two tail t-test of student. Water concentration measured by the four FTIRs was also in good agreement. Moreover, the dry emissions of CO2 and CO measured by the laboratory non-dispersive infrared (NDIR) and corrected using water were a few percentages different from those obtained using the regulated carbon-based approach. The results indicate that all the investigated systems are suitable for the measurement of the investigated gaseous compounds, including CO2 and H2O. [ABSTRACT FROM AUTHOR]

Nitrous oxide (N2O) is the third most important greenhouse gas modified by human activities after carbon dioxide and methane. This study examines the feasibility of airborne differential absorption lidar to measure N2O concentration enhancements over agricultural, fossil fuel combustion, industrial, and biomass burning sources. The mid-infrared spectral region, where suitably strong N2O absorption lines exist, challenges passive remote sensing by means of spectroscopy due to both low solar radiation and thermal emission. Lidar remote sensing is principally possible thanks to the laser as an independent radiation source but has not yet been realized due to technological challenges. Mid-infrared N2O absorption bands suitable for remote sensing are investigated. Simulations show that a spectral trough position between two strong N2O lines in the 4.5 µm band is the favored option. A second option exists in the 3.9 µm band at the cost of higher laser frequency stability constraints and less measurement sensitivity. Both options fulfill the N2O measurement requirements for agricultural areal or point-source emission quantification (0.5 % measurement precision, 500 m spatial resolution) with technically realizable and affordable transmitter (100 mW average laser power) and receiver (20 cm telescope) characteristics for integrated-path differential absorption lidar that measures the column concentration beneath the aircraft. The development of an airborne N2O lidar is feasible yet would benefit from progress in infrared laser transmitter and low-noise-detection technology. It will also serve as a precursor to space versions, which are still out of reach due to the lack of space technology. [ABSTRACT FROM AUTHOR]

In this work, we report a long-wave infrared (LWIR) modulator based on the two-photon absorption of CO2 gas. The effect of gas pressure and laser power on the modulation under different wavelengths is discussed. A maximum modulation depth of 21.5% with a rise time (full time) less than 20 ns for a 9.36 μm laser was achieved. The gaseous modulator, which adopts a 2.75 μm laser as the pumping source, is capable of converting the pulse characteristics of the pump light into the modulation of the long-wave infrared light. It demonstrates promising potential for applications in the rapid optical modulation of LWIR lasers. [ABSTRACT FROM AUTHOR]

A spatiotemporal understanding of gene function requires the precise control of gene expression in each cell. Here, we use an infrared laser–evoked gene operator (IR-LEGO) system to induce gene expression at the single-cell level in the moss Physcomitrium patens by heating a living cell with an IR laser and thereby activating the heat shock response. We identify the laser irradiation conditions that provide higher inducibility with lower invasiveness by changing the laser power and irradiation duration. Furthermore, we quantitatively characterize the induction profile of the heat shock response using a heat-induced fluorescence reporter system after the IR laser irradiation of single cells under different conditions. Our data indicate that IR laser irradiation with long duration leads to higher inducibility according to increase in the laser power but not vice versa, and that the higher laser power even without conferring apparent damage to the cells decelerates and/or delayed gene induction. We define the temporal shift in expression as a function of onset and duration according to laser power and irradiation duration. This study contributes to the versatile application of IR-LEGO in plants and improves our understanding of heat shock-induced gene expression. A study optimizes a system effectively inducing gene expression by infrared laser heating and characterizes the induction profile of single cells in the different conditions through quantitative imaging analysis in the moss Physcomitrium patens. [ABSTRACT FROM AUTHOR]

Direct laser acceleration with radially polarized lasers is an intriguing variant of laser-based particle acceleration that has the potential of offering GeV/cm-level energy while avoiding the instabilities and complex beam dynamics associated with plasma wakefield accelerators. A major limiting factor is the difficulty of generating high-power radially polarized beams. In this paper, we propose the use of CO2-based long-wave infrared (LWIR) lasers as a driver for direct laser acceleration, as the polarization insensitivity of the gain medium allows a radially polarized beam to be amplified. Additionally, the larger waist sizes, Rayleigh lengths, and pulse lengths associated with the long wavelength could improve the injection efficiency of the electron beam. By comparing acceleration simulations using a near-infrared laser and an LWIR laser, we show that the injection efficiency is indeed improved by up to an order of magnitude with the longer wavelength. Furthermore, we show that even sub-TW peak powers with an LWIR laser can provide MeV-level energy gains. Thus, radially polarized LWIR lasers show significant promise as a driver of a direct laser-driven demonstration accelerator. [ABSTRACT FROM AUTHOR]

As an important part of traditional Chinese architecture, Fuzhou's ancient houses have unique cultural and historical value. However, over time, environmental factors such as efflorescence and plant growth have caused surface damage to their gray brick walls, leading to a decline in the quality of the buildings' structure and even posing a threat to the buildings' safety. Traditional damage detection methods mainly rely on manual labor, which is inefficient and consumes a lot of human resources. In addition, traditional non-destructive detection methods, such as infrared imaging and laser scanning, often face difficulty in accurately identifying specific types of damage, such as efflorescence and plant growth, on the surface of gray bricks and are easily hampered by diverse surface features. This study uses the YOLOv8 machine learning model for the automated detection of two common types of damage to the gray brick walls of Fuzhou's ancient houses: efflorescence and plant growth. We establish an efficient gray brick surface damage detection model through dataset collection and annotation, experimental parameter optimization, model evaluation, and analysis. The research results reveal the following. (1) Reasonable hyperparameter settings and model-assisted annotation significantly improve the detection accuracy and stability. (2) The model's average precision (AP) is improved from 0.30 to 0.90, demonstrating good robustness in detecting complex backgrounds and high-resolution real-life images. The F1 value of the model's gray brick detection efficiency is improved (classification model performance index) from 0.22 to 0.77. (3) The model's ability to recognize the damage details of gray bricks under high-resolution conditions is significantly enhanced, demonstrating its ability to cope with complex environments. (4) The simplified data enhancement strategy effectively reduces the feature extraction interference and enhances the model's adaptability in different environments. [ABSTRACT FROM AUTHOR]

The crustacean Daphnia magna is an emerging model for ecological and toxicological genomics. However, the lack of methods for spatial and temporal control of gene expression has impaired the elucidation of molecular mechanisms underlying responses to environments in vivo. Here we report local activation of the hsp70 promoter-driven gene cassette in D. magna by the infrared laser-evoked gene operator (IR-LEGO), a method for heating the target cells with infrared irradiation. We identified the heat-inducible promoter upstream of the D. magna hsp70-A gene. Using this promoter, we generated a transgenic Daphnia harboring the heat-shock responsive GFP reporter gene and confirmed that the GFP gene responds to heat treatment not only in juveniles and adults but also in embryos. We collected embryos from the reporter line and irradiated four different regions of interest in the embryos: a proximal region of the third thoracic segment, a part of the midline, a second maxilla, and a distal region of the endopodite of the second antenna, all of which increased GFP fluorescence with an infrared laser. Our results suggest that the IR-LEGO method is useful for spatial and temporal control of gene expression and would advance the functional genomics in D. magna. [ABSTRACT FROM AUTHOR]

Thermogenetics is a promising neuromodulation technique based on the use of heat-sensitive ion channels. However, on the way to its clinical application, a number of questions have to be addressed. First, to avoid immune response in future human applications, human ion channels should be studied as thermogenetic actuators. Second, heating levels necessary to activate these channels in vivo in brain tissue should be studied and cytotoxicity of these temperatures addressed. Third, the possibility and safety of chronic neuromodulation has to be demonstrated. In this study, we present a comprehensive framework for thermogenetic neuromodulation in vivo using the thermosensitive human ion channel hTRPV1. By targeting hTRPV1 expression to excitatory neurons of the mouse brain and activating them within a non-harmful temperature range with a fiber-coupled infrared laser, we not only induced neuronal firing and stimulated locomotion in mice, but also demonstrated that thermogenetics can be employed for repeated neuromodulation without causing evident brain tissue injury. Our results lay the foundation for the use of thermogenetic neuromodulation in brain research and therapy of neuropathologies. [ABSTRACT FROM AUTHOR]

Resonant collisional radiative transfer of the vibrational energy between molecules subjected to infrared laser multiphoton excitation in a two-component medium has been studied. Experiments have been carried out with BCl3 molecules of the natural isotopic composition in a mixture with CH3F molecules, which are optically active sensitizers and acceptors of radicals. Both types of molecules resonantly absorb laser radiation. Resonant collisional radiative energy transfer from CH3F molecules to 10BCl3 ones has been observed. It has been shown that this process significantly increases the dissociation yield of 10BCl3 and 11BCl3 molecules compared to the dissociation yield with neutral acceptors of radicals. Dependences of the dissociation yields of BCl3 molecules on the pump laser frequency have demonstrated a structure that closely correlates with the structure of the infrared absorption spectrum of CH3F molecules. The method has been described and the experimental results have been reported. Conditions for efficient resonant collisional radiative transfer of the vibrational energy between molecules subjected to infrared laser multiphoton excitation have been discussed. [ABSTRACT FROM AUTHOR]

Dental fear and phobia are prevalent worldwide, with local anesthesia being the most feared procedure. This study aimed to determine whether photobiomodulation therapy (PBMT), used as a pre‐anesthetic, could modulate puncture pain and enhance the effectiveness of local anesthesia. In this controlled, randomized, double‐blind study, 49 participants were divided into an experimental group (n = 24), which received infrared laser therapy (100 mW, at 808 nm, 8 J, 80 s at a single point) immediately before standard anesthesia; and control group (n = 25), which received the standard anesthetic technique and sham laser. Pain levels were measured using the visual analog scale, and anesthetic efficacy was assessed through electrical tests (latency), percentage of failures, and cartridge usage. Anxiety levels were evaluated using the Beck Anxiety Inventory. Cardiovascular parameters were evaluated through blood pressure, oxygen levels, and heart rate. This randomized, double‐blind study found no difference between groups in these experimental conditions. The bias toward a positive PBMT result was sufficiently removed. Autonomic responses of the PBMT group were maintained stable during the procedure. [ABSTRACT FROM AUTHOR]

Photodynamic therapy (PDT) is a promising cancer treatment approach. Indocyanine green (ICG) is a water-soluble tricarbocyanine dye with a peak absorption wavelength of around 800 nm and possesses the capacity to produce reactive oxygen species. FTIR spectroscopy is rarely used and offers insights into molecular changes in cancer studies. MCF-7 cells were injected into Nude mouse. Once the tumor had grown to a size of 3–4 mm, mice were randomized into the 12 PDT groups. After each mouse received 5 mg/kg of ICG, they were photo-irradiated with a diode laser emitting light at 809 nm, followed by waiting intervals of 0, 30, 60, and 90 min. Laser irradiation parameters were 150, 250, 500 mW/cm2 and irradiation duration was 1200s. The tumor size was measured every day for four days. The FTIR spectroscopy was used to perform spectral analysis on tumor tissue samples. Four distinct regions (3600–2800 cm-1, 1750–1550 cm-1, 1540–1450 cm-1, and 1700–1100 cm-1) were analyzed, and Hierarchical Cluster study was carried out. A decrease in tumor volume was observed with all PDT applications, except, increases in tumor volume was observed at 150mW 90-minute group. PDT administered after 90 min revealed variations in 150mW and 250mW laser powers in the 3600 cm-1–2800 cm-1 range. The 250mW and 500mW applications resulted in a considerable reduction in fibroadenoma and carcinoma tissues, according to an analysis comparing the A1695 / A1635 ratio. It is proposed that the ideal treatments for further investigation have a power output of 250 mW. [ABSTRACT FROM AUTHOR]

Study on static in-situ curing characteristics of CFRP based on near infrared laser: The quick curing method of carbon fibre reinforced plastics (CFRP) is one of the hotspots in current research. A static in-situ curing method for CFRP prepreg based on near-infrared laser was put forward in this study. The in-situ curing structural characteristics and the mechanism of CFRP were investigated through real-time surface temperature measurement, COMSOL temperature field simulation, 3D measurement of curing morphology and resin curing degree test. The thermal conductivity of the CFRP along the fiber direction is considerably higher than that along the perpendicular fiber direction. As a result, the temperature profile in the plane takes on an elliptical shape. During the transfer, the temperature field gradually decreases, resulting in an ellipsoidal 3D high-temperature distribution. The different shrinkage phenomena in the different curing regions between the layers lead to an irregular ellipsoidal solidification morphology of the unidirectional CFRP. The temperature in the center of the heat affected zone increases as a power exponential function with time. The area and depth of the heat-affected zone increases with the laser power, and the curing area is positively correlated with the degree of curing. As a result, curing temperature governing equations based on laser power and layer thickness have been proposed, while relationship equations based on laser power, curing depth and curing morphology have been developed. In addition, prediction equations based on curing morphology have been developed for curing degree, in order to achieve precise curing of CFRP. [ABSTRACT FROM AUTHOR]

Quiet optical discharge in high-pressure xenon is visually stable pre-breakdown stage of optical discharge supported by pulse-periodic short-wavelength infrared laser radiation with intensity of the order of 109 W/cm2. Increasing the laser intensity leads to the transition of the quiet discharge into a pulse-periodic optical breakdown. In this study, quasi-stationary directional flows generated by both the quiet discharge and the optical breakdown are observed. The flows and their initial stages under limited number of discharge pulses are visualized by shadow imaging method using a point-like laser-plasma radiation source. It is shown that the gas streams outflow points in a quiet discharge correspond to the positions of the laser radiation intensity local maxima in the focal beam waist with astigmatism complicated by defocusing effect of thermal lens arising in the discharge zone. The pulse-periodic optical breakdown emits a turbulent gas flow toward the laser beam. The beam refraction on density gradients in the turbulent flow causes the breakdown instability from pulse to pulse. It was found that time-average absorption of laser radiation in a quiet discharge is about 3% (also in a pulse), while that in optical breakdown is 15% and higher (from 70% to 100% in a pulse). Laser beam intensity for quiet discharge at pulse repetition rate νp = 20 kHz ranges from 1.3 × 109 to 1.5 × 109 W/cm2. At intensities above 4 × 109 W/cm2 and repetition rates νp > 50–55 kHz, laser breakdowns are observed in each laser pulse with the focal ratio f/d ≤ 7. At f/d = 10.6 and νp > 28 kHz, the quiet discharge does not transit to laser breakdown due to defocusing by the thermal lens induced. [ABSTRACT FROM AUTHOR]

Infrared matrix‐assisted laser desorption electrospray ionization (IR‐MALDESI) uses an infrared laser to desorb neutral biomolecules with postionization via ESI at atmospheric pressure. The Gaussian profile of the laser with conventional optics results in the heating of adjacent nonablated tissue due to the energy profile being circular. A diffractive optical element (DOE) was incorporated into the optical train to correct for this disadvantage. The DOE produces a top‐hat beam profile and square ablation spots, which have uniform energy distributions. Although beneficial to mass spectrometry imaging (MSI), it is unknown how the DOE affects the ability to perform quantitative MSI (qMSI). In this work, we evaluate the performance of the DOE optical train against our conventional optics to define the potential advantages of the top‐hat beam profile. Absolute quantification of glutathione (GSH) was achieved by normalizing the analyte of interest to homoglutathione (hGSH), spotting a dilution series of stable isotope labeled glutathione (SIL‐GSH), and analyzing by IR‐MALDESI MSI with either the conventional optical train or with the DOE incorporated. Statistical comparison indicates that there was no significant difference between the quantification of GSH by the two optical trains as evidenced by similar calibration curves. Results support that both optical trains can be used for qMSI without a change in the ability to carry out absolute quantification but providing the benefits of the top‐hat optical train (i.e., flat energy profile and square ablation spots)—for future qMSI studies. [ABSTRACT FROM AUTHOR]