Red Laser Beam Research Articles

Photoimmunotherapy in nasopharyngeal carcinoma recurrence.

6068 Background: Photoimmunotherapy is a novel anticancer treatment developed by the NCI and has been covered by insurance in Japan since January 2021 for patients with unresectable, locally advanced or locally recurrent head and neck cancers. Over 400 patients have been treated with photoimmunotherapy in Japan, including 19 cases with recurrent nasopharyngeal carcinoma. Photoimmunotherapy uses an antibody-drug conjugate, cetuximab sarotalocan sodium, comprising cetuximab, a chimeric monoclonal antibody (IgG1) that targets human EGFR, and a light-sensitive dye, IRDye 700DX (IR700). The conjugate exhibits a strong affinity for cells expressing EGFR, which is enhanced in HNSCC. When exposed to a 690 nm (red) laser beam from the BioBlade laser system, the dye is activated, resulting in selective and rapid death of cells to which the conjugate is bound. The mechanism involves: (i) activation of the antibody conjugate by laser illumination, (ii) damage to the cell membrane, (iii) increased transmembrane water flux, and (iv) cell rupture and necrosis. The entire process occurs rapidly following laser illumination. Nasopharyngeal carcinoma is primarily treated with radiation therapy; however, if it persists, therapy becomes challenging. Surgical intervention for local recurrence or residual disease can be difficult due to the anatomical characteristics of the disease. Drugs and re-irradiation have limited effectiveness and significant adverse events have been reported. Photoimmunotherapy is considered more effective for nasopharyngeal carcinoma than other treatment sites. Methods: Nineteen patients with recurrent residual nasopharyngeal carcinoma following irradiation, who were treated with photoimmunotherapy at 15 centers across Japan, were reviewed. The study analyzed patients’ previous treatment regimens, laser irradiation methods employed in photoimmunotherapy, and pathological characteristics before and after treatment. Results: The mean observation duration was 368 days (median 302 days). A total of 10 patients received photoimmunotherapy once, 5 received it twice, 2 received it three times, and 2 received it four times. Final local control was achieved in 14 patients with CR, 3 with PR and 1 with SD. Regrettably, 3 patients developed distant metastases after the start of photoimmunotherapy. At the end of the observation period, 11 patients were disease-free, 6 were alive with cancer, and 2 died of carotid artery rupture despite achieving local tumor control. The overall survival rate at 1 year was 88.2 %. Conclusions: The outcomes of the photoimmunotherapy demonstrated successful local control of recurrent nasopharyngeal carcinoma. This innovative therapeutic approach holds significant potential for addressing nasopharyngeal cancer recurrence. However, it is crucial to carefully evaluate patients who can safely be treated using this method.

Deep automatic soil roughness estimation from digital images

ABSTRACT Soil roughness, defined as the irregularities of the soil surface, yields significant information about soil water storage, infiltration and overland flow and, thus, is a key factor in characterizing the quality of the terrain; it is often used as input in many synthetic general agricultural models and in particular in soil moisture estimation models. In this paper, we propose a framework that combines a specific setup for data acquisition with deep convolutional networks for actual estimation. The former relies on projecting a line red laser beam on the analysed soil surface followed by digital color image acquisition. The later, involves two convolutional models that are trained in a supervised manner to predict the soil roughness. The data set was produced in the laboratory both on synthetic and real soil samples. The labels used in the training process are the soil roughness values measured by using a pinboard. The detailed evaluation showed that the error of the automatic precision lies in the range of ground truth deviation, thus validating the proposed procedure.

Interaction of Culture Medium and Artificial Light Type on Pigmentation of Micro-Propagated Opuntia Plants

Opuntia is recognized economically as a significant crop for its nutritional, functional, and therapeutic properties and its potential in the pharmaceutical, cosmetic, and bioenergy industries. Opuntia is conventionally propagated by seed or vegetative propagation via rooted scions or grafting. However, multiplication procedures are insufficient for extensive spreading. One of the alternative techniques is in vitro. For this reason, the objective was to evaluate the growth of different components combined with light conditions to induce callus, embryogenesis, and the possible synthesis of a component in the genus Opuntia. The existence of genes involved in pigment synthesis in genotypes of different fruit colors was complementarily analyzed. In this study, we used different combinations of fructose (2 g/L) with prickly pear juice (2 mL/L), mannitol (4 g/L), silver nitrate (AgNO3: 1 mg/L), 2,4-dichlorophenoxyacetic acid (2,4-D: 2 mg/L), and indole-3-acetic acid (IAA: 1 g/L), with white, blue, and red LEDs (light-emitting diodes) and laser beams. These explants yielded sufficient contents of simple phenols, gallic acid equivalents (GAE: 2283.30 ± 6.29 mg/100 g), and coumaric (2155.0 ± 35.0 mg/100 g) and ferulic (2176 ± 27.9 mg/100 g) acids for the genotype Tapón aguanoso, and chlorogenic acid (CGA: 380.22 ± 22.05 mg/100 g) for the Copena V1 genotype. Upon analyzing the genotypes of different fruit pigmentations, we also observed the following: enzyme 4,5 estradiol dioxygenases can be present in all genotypes (regardless of pigmentation); enzyme 5,3 glucosyltransferases (GTs) could be induced in pigment synthesis in the genotypes of orange to purple fruits. Sequencing primer-amplified fragments for GT showed high similarity to uridine diphospho (UDP)-glucose from other species. This allows us to infer that it is possible to obtain products of high therapeutic value in the near future under controlled conditions.

Silicea terra 200cH evaluated by two different spectroscopy methods: a pilot study

Abstract
 Spectroscopy has been shown to be a useful method to study the physicochemical properties of homeopathic preparations. In this pilot study, the aim was to compare two methods (photon scattering and visible-light spectroscopy) in the physical evaluation of Silicea terra 200cH. Two samples have been examined and compared: Silicea terra 200cH and Sac lac 200cH, both prepared in aqueous solution (Cemon Lab, Italy). Lactose was included because the first 3 potencies of Silicea terra are made by trituration in lactose. In the first test, performed in Italy, slight variations in chrominance and luminance due to micro-vibrational 3D phenomena were analyzed. The principle of the experimental procedure is to modify and analyse the incidence and refraction angles of the light hitting the bottles of liquid under examination. Measurements were made using an innovative camera device developed by Daniele Gullà, called MIRA/CORA (proprietary name). The image sensor is a Charge-Coupled Device (CCD)/ Complementary Metal Oxide Semiconductor (CMOS) with interferential matrix filter. A red laser beam, at wavelength 652 nm, hits the bottle and the variations of scattered light are recorded and measured by the device. All measurements have been performed in a dark room at a constant temperature of 22°C +/- 0,2°C using a filter with very narrow spectral bands (10 nm). Proprietary software analyses the incoming frames showing the spectral variations in amplitude and frequency and then interpolates variation in the measured data within a vibrational range between 0.01 Hz and 10 Hz. The measurements have been repeated three times on both Silicea terra 200cH and Sac lac 200cH within a few minutes of each other. Measurements of the mean entropy of the signals, statistically elaborated with T Student test, yielded a two tailed p value < 0.05, where the entropy of the signal recorded from the Silicea terra 200cH sample was statistically lower than the 200cH Sac lac sample. In the second test, performed in Brazil, variations in absorbance were used to identify Silicea terra 200cH compared with Sac lac 200cH and a control solution of non-succussed 30% alcohol, using six solvatochromic dyes, following the method developed by Cartwright [1,2]. Both homeopathic samples were imported from Italy, diluted 1:100 in 30% hydro-alcoholic solution, and submitted to 100 succussions using an automatic mechanical arm (Denise, AUTIC, Brazil) prior to being tested. Samples were inserted into dyes solutions in a 1:60 ratio, and evaluated by visible spectroscopy (FEMTO Spectrophotometer, Brazil). Dyes were prepared in ethanol P.A., according to previous established methods [3]. Samples and dyes were protected from light during the manipulation and environmental conditions of the laboratory (temperature, humidity, and magnetic flux) were monitored during the tests. Three series in triplicate were performed and the results were analyzed by ANOVA / Tukey, comparing both samples and the unsuccussed 30% hydroalcoholic control solution. Among all tested dyes, only BDN showed an interaction with Silicea terra 200cH, reproducing the conclusions obtained in [3]. We conclude that two different spectroscopic methods were able to differentiate Silicea terra 200cH from Sac lac 200cH, suggesting that changes in solvent organization could be involved in the homeopathic signaling process, along with changes in dipole moments of solvent and dyes. The results are potentially in line with a recent published paper [4], that supports the proposition that the lower entropy of the verum signal compared with controls could be explained by increased coherent vibrations of the verum sample, modulated by Nambu-Goldstone bosons. According to Del Giudice and colleagues [5], coherent behaviors are correlated with massless quasi-particles, coding ordering information.

Effect of exposing the seeds of tomato plant (Solanum lycopersicum L.) to diode laser rays on the germination, growth of hypocotyl stems callus of their seedlings and its content of lycopene

The current study succeeded in demonstrating the role of red laser beams at a wavelength of 650 nm and a power of 50 milliwatts / cm2 when exposed to the seeds of the tomato plant Solanum lycopersicum L. at times of 0,5,10,15 minutes on their germination rate and seedlings growth, and then estimating the growth of its callus and its content of lycopene. Also the results showed that the time period of 10 minutes exceeded others in encouraging seed germination with a full percentage (100%) after 5 days of planting them on solid Murashige and Skoog (MS) medium with distinct growth of its seedlings, whose roots and vegetative total lengths reached 3.9, 7.1 cm after 20 days compared to seeds not exposed to radiation, the percentage reached 80% after 7 days, with seedlings growing at a rate of 2.3 and 3.4 cm, respectively. The study was able to initiate callus by cutting stems of its sub cotyledon seedlings on MS medium supplemented with 2.0 mg /l TDZ and 0.5 mg/l NAA.

Bio-Surfactant Assisted Aqueous Exfoliation of High-Quality Few-Layered Graphene

Realizing the efficacy of the liquid-phase exfoliation technique to obtain a greater quantity of graphene, this study demonstrates a cost-effective technique of bio-surfactant-assisted liquid-phase exfoliation of few-layer graphene (FLG) with a low defect ratio. An ultrasonic bath without any toxic chemicals or chemical modification was employed to exfoliate the graphene at room temperature. Several state-of-the-art characterization techniques such as TEM, AFM, XRD UV-Vis, and Raman spectroscopy were used to confirm the presence of the graphene. The dispersion exhibits a typical Tyndall scattering to the red laser beam. After a 7-h sonication of the dispersion, followed by a centrifugation frequency of 500 rpm for half an hour, the graphene concentration was found to be 1.2 mg/mL. The concentration decreases monotonically with an increase in the frequency, as a higher frequency causes sedimentation of the larger flakes or removes the adsorbed surfactant molecules from the graphene structures that collapse the graphene sheets into the graphite. The presence of an amino acid head-group in the surfactant facilitated exfoliation in an aqueous solution at well below the critical micelle concentration (CMC) of the surfactant. The product demonstrates all characteristic features of an FLG system. The TEM and AFM image reveals large-area graphene with a wrinkle-free surface; these morphological properties are confirmed by XRD and Raman spectroscopy. This study suggests that a sonication-induced process with a biocompatible surfactant can produce a cheap, large-surface-area graphene system for a wide range of applications. Moreover, the use of a probe sonicator as an alternative to the bath-type sonicator, together with the demonstrated technique, may reduce the time needed, and leads to a manifold increase in the yield.

Measuring Droplets Expelled During Endoscopy to Investigate COVID-19 Transmission Risk

Measuring Droplets Expelled During Endoscopy to Investigate COVID-19 Transmission Risk

Diffusion Reflection Method for Early Detection of Oral Squamous Cell Carcinoma Specifically Targeted by Circulating Gold-Nanorods Bio-Conjugated to Anti-Epidermal Growth Factor Receptor.

BackgroundTranslation of nanomedical developments into clinical application is receiving an increasing interest. However, its use for oral squamous cell carcinoma (OSCC) diagnosis remains limited. We present an advanced nanophotonic method for oral cancer detection, based on diffusion reflection (DR) measurements of gold-nanorods bio-conjugated to anti-epidermal growth factor receptor (C-GNRs) specifically attached to OSCC cells.ObjectiveTo investigate in a rat model of oral carcinogenesis the targeting potential of C-GNRs to OSCC by using the DR optical method.Materials and MethodsOSCC was induced by the carcinogen 4-nitroquinoline-N-oxide (4NQO). C-GNRs were introduced locally and systemically and DR measurements were recorded from the surface of the rat tongue following illumination with red laser beam. Rats were divided into experimental and control groups. The results were compared with the histologic diagnosis.ResultsA total of 75 Wistar-derived rats were enrolled in the study. Local application did not reveal any statistical results. DR measurements following intravenous injection of C-GNRs revealed a significant increase in light absorption in rats with OSCC compare with rats without cancer (p<0.02, sensitivity 100%, specificity 89%). In addition, absorption of light increased significantly in cases of severe dysplasia and cancer (high risk) compared to rats without cancer and rats with mild dysplasia (low risk) (86% sensitivity and 89% specificity, AUC=0.79).ConclusionCombining nanotechnology and nanophotonics for in vivo diagnosis of OSCC serves as additional tier in the translation of advanced nanomedical developments into clinical applications. The presented method shows a promising potential of nanophotonics for oral cancer identification, and provides support for the use of C-GNRs as a selective drug delivery.

EFFECTS OF LASER IRRADIATION ON NORMAL AND ANEMIC HUMAN BLOOD

The effects of laser irradiation on the whole human blood were studied. The blood samples were taken from healthy donors with normal blood and donors with anemic blood. The blood samples were exposed to laser radiation. Two lasers of the same types, continuous wave (CW) diode pumped solid-state lasers (DPSSL’ s) were used to irradiate the blood samples. One of these laser has a wavelength 532 nm (green laser beam), while the other laser has a wavelength 671 nm (red laser beam). The output power of the two lasers can be varied over the range 0 - 100 mW. In the present study, the output power was fixed at 20 mW for both lasers. The blood samples were exposed to different irradiation times, 5, 15, and 30 min. Significant changes in the optical parameters of the irradiated blood samples were observed in comparison with that of the un-irradiated blood samples (the control samples). These optical parameters were determined from the measured absorbance spectra of the un-irradiated and irradiated samples. The absorbance spectra were measured using a UV-Visible double-beam spectrophotometer operating over the wavelength range 190 - 1100 nm.&#x0D; The results of the present study revealed that the laser irradiation can produce considerable effects on the human blood samples, suggesting the suitability of the laser beam irradiation for the biological and medical applications.

Low-cost laser measurement gauge for real-time quality control of boards and sheets production

This paper describes the conception, the development and the testing of a prototype of a simple and versatile device for micro displacement measurement and thickness monitoring of paper sheets and opaque or transparent plastic films during their fabrication. The device works based on triangulation using low power red diode laser beams for the measurements and low-cost Silicon photodiodes for light detection. The system reproductibility was evaluated as well as experimental simulations for thickness variation detection on adhesive tapes were carried out. The results showed that the gauge is capable to detect and measure thickness variations smaller than 5 µm in real time and can be easily implemented in a production system.

NV Center Charge State Controlled Graphene-on-Diamond Field Effect Transistor Actions With Multi-Wavelength Optical Inputs

We demonstrate graphene-on-diamond field effect transistor (FET) actions modulated by optically excited charge state of nitrogen-vacancy (NV) centers in diamond. Palladium (Pd) metal contacts on graphene serve as the source and the drain. Negative charge state NV <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-</sup> center in diamond serves as the gate with diamond being the gate dielectric and produces an electric field to enhance the hole concentration in the graphene channel. The conductivity of graphene varies with negative charge state NV <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-</sup> center, resulting in differential conductance. The negative gate bias is removed when a NV <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-</sup> center is converted to an NV <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sup> center. P-type graphene channel exhibits positive differential conductance under illumination by a blue (405 nm) laser beam while on the contrary negative differential conductance by a red (633 nm) laser beam. Furthermore, by simultaneous illumination of both blue and red laser beams, effects on differential conductance decrease according to the relative intensity of the two laser beams. Graphene FETs with wavelength dependent multiple optical inputs and one electrical output in response to the charge state of NV centers in diamond has been reported.

Стимуляция экспрессии гена col2a1 низкоинтенсивным лазерным излучением--инструмент для индукции образования хрящевой ткани

Multipotent stem cells rat bone marrow irradiated with a low-intensity red laser beam (0.63 µm, 1.7 mW) demonstrated an increase of expression of col2a1 gene that is responsible for the synthesis of type II collagen, which is one of the most abundant proteins of the extracellular matrix of hyaline cartilage. The results show the applicability this effect in the treatment of diseases whose development is associated with surface damage of articular cartilage.

Simultaneous Spectral and Spatial Modulation for Color Printing and Holography Using All-Dielectric Metasurfaces.

Metasurfaces possess the outstanding ability to tailor phase, amplitude, and even spectral responses of light with an unprecedented ultrahigh resolution and thus have attracted significant interest. Here, we propose and experimentally demonstrate a novel meta-device that integrates color printing and computer-generated holograms within a single-layer dielectric metasurface by modulating spectral and spatial responses at subwavelength scale, simultaneously. In our design, such metasurface appears as a microscopic color image under white light illumination, while encrypting two different holographic images that can be projected at the far-field when illuminated with red and green laser beams. We choose amorphous silicon dimers and nanofins as building components and use a modified parallel Gerchberg-Saxton algorithm to obtain multiple subholograms with arbitrary spatial shapes for image-indexed arrangements while avoiding the loss of phase information. Such a method can further extend the design freedom of metasurfaces. By exploiting spectral and spatial control at the level of individual pixels, multiple sets of independent information can be introduced into a single-layer device; the additional complexity and enlarged information capacity are promising for novel applications such as information security and anticounterfeiting.

Using Polymers and Pigments to Produce Laser Interference Rings

When a laser of sufficient intensity is shined into a pigmented transparent medium, the partially absorbed laser light can heat and change the refractive index of the medium in the path of the beam. This altered medium will in turn cause the transmitted laser light to thermally defocus into a series of concentric rings. Some solvents such as 2-propanol and a variety of polymers such as polystyrene, polyethylene terephthalate, and polydimethylsiloxane can be pigmented with a variety of colors. Samples of various colors can be used to spectacularly demonstrate characteristics of light absorption. For example, a 2-propanol solution containing methyl red in red acidic form will absorb a green laser and produce interference rings, but a solution of methyl red in yellow basic form will not. As another example, a red laser beam will pass unaffected through a red pigmented film, but the beam will heat a green film (e.g., from a green pigmented polyethylene terephthalate soda bottle) to produce interference rings. Additionally, since the pattern produced is based on the interference of light waves, these demonstrations reinforce concepts associated with the wave nature of light.

Multifunctional Dielectric Metasurfaces Consisting of Color Holograms Encoded into Color Printed Images

AbstractA hologram records the wavefront of light from an object, but it is usually not an image itself, and looks unintelligible under diffuse ambient light. Here a new paradigm to encode a color hologram onto a color printed image is experimentally demonstrated. The printed image can be directly viewed under white light illumination, while a low‐crosstalk color holographic image can be seen when the device is illuminated with red (R), green (G), and blue (B) laser beams. The device is a dielectric metasurface that consists of titanium dioxide (TiO2) cones on a glass substrate. The dimensions of the TiO2 cones are chosen to allow them to support visible‐wavelength resonances, thereby producing the desired reflection spectra and thus the color printed image. The detour phase method is furthermore used to encode the hologram into the metasurface. The approach is conceptually different from previously demonstrated color printed images or holograms and presents opportunities for optical document security and data storage applications.

Fabrication and remote laser ignition of Al/CuO energetic nanocomposites incorporated with functional dyes for enhanced light absorption

In this study, we investigated the effects of dyes on the laser ignition characteristics of Al nanoparticles (NPs) and CuO NPs-based energetic nanocomposites. Various functional dyes (e.g., N-719, rose bengal (RB), methylene blue (MB)) were employed as a light absorbing medium for Al/CuO energetic nanocomposites. According to UV–vis spectrometer analysis results, N-719, RB, and MB dyes had relatively strong light absorption in the blue, green, and red wavelength ranges, respectively. The results of red, green, and blue (RGB) laser ignition tests for various dye-coated Al/CuO composites demonstrated that the laser ignition threshold power density for the composites gradually decreased with increasing dye concentration. To test the possibility of selective optical ignition, the various dye-coated Al/CuO composites were irradiated using RGB laser beams operating with a fixed and relatively low power density. The results showed that the N-719-, RB-, and MB-coated Al/CuO composites were only successfully ignited under the condition of blue, green, and red laser beam irradiation, respectively. This suggests that energetic nanocomposites coated with special dyes could be employed as potential igniters and heat energy sources, the reactions of which are initiated by selective and remote light-energy irradiation, in various thermal engineering applications.

Electronic structure and conformational isomerism of the digermene (tBu2MeSi)2Ge=Ge(SiMetBu2)2 as studied by temperature-dependent Raman and UV–vis spectra and quantum-chemistry calculations

The structure of the digermene (tBu2MeSi)2Ge=Ge(SiMetBu2)2 (1) was investigated by experimental (Raman and UV–vis) as well as computational (NCA, TD DFT and QTAIM) methods. Temperature-dependent Raman and UV–vis spectra have demonstrated that 1 does not dissociate into the corresponding germylenes on heating either to 120 °C as a solid or to 80 °C in solution, thus preserving the integrity of its double Ge=Ge bond. Raman and NCA results allowed one to estimate the region of the νGe=Ge vibrational frequency in the spectra of digermenes as 270–340 cm−1. When illuminated with a red laser beam of enhanced power (>5 mW), solid 1 undergoes a transformation followed by disappearance of the νGe=Ge Raman band. This process is evidently photodissociation caused by proximity of the red laser wavelength 632.8 nm to the intrinsic absorption of 1 at 616 nm. Temperature dependence of the Raman spectrum has revealed conformational isomerism in solid digermene 1 due to hindered rotation about the Ge–Si bonds, the conformers differing in mutual disposition of Me and bulky tBu groups.

Application of Z-scan technique for the study of nonlinear absorption in chemically reduced LiNbO3 crystals

The nonlinear absorption (NLA) was studied by open-aperture Z-scan experiments in the chemically reduced nominally pure LiNbO3 crystals at cw-illumination with the red (644 nm) and green (514.5 nm) laser beams. The magnitude of the measured NLA is considerably different from the reported Z-scan results obtained in as-grown LiNbO3. The positive sign of NLA obtained with the red light has been related to the generation of the small bound polarons absorbing in red and near-IR ranges. Application of green light results in the light-induced transparency, i.e. the Z-scan traces show negative sign of NLA. Intensity dependence of Z-scan traces allows for conclusion that the photo-induced dissociation of small NbLi4+:NbNb4+ bipolarons and sequent generation of small polarons gives the dominating contribution to the nonlinear optical absorption in reduced crystals with a large bipolarons concentration.

Time resolved nonlinear response of Sn2P2S6:Sb to nanosecond pulse excitation

The temporal variations of SPS:Sb transmission are measured within a 10 orders of magnitude time range (from a few nanoseconds to ten seconds) with a red diode laser beam, after illumination of the sample with a nanosecond pulse of green light. The measurements revealed a sequence of darkening and bleaching processes that are sensitive to the intensities of pre-illumination and testing beams, or the sample temperature, or both. This allowed for identifying particular nonlinear processes that manifest themselves in changes of transmission.

Direct and parametric synchronization of a graphene self-oscillator

We explore the dynamics of a graphene nanomechanical oscillator coupled to a reference oscillator. Circular graphene drums are forced into self-oscillation, at a frequency fosc, by means of photothermal feedback induced by illuminating the drum with a continuous-wave red laser beam. Synchronization to a reference signal, at a frequency fsync, is achieved by shining a power-modulated blue laser onto the structure. We investigate two regimes of synchronization as a function of both detuning and signal strength for direct (fsync≈fosc) and parametric locking (fsync≈2fosc). We detect a regime of phase resonance, where the phase of the oscillator behaves as an underdamped second-order system, with the natural frequency of the phase resonance showing a clear power-law dependence on the locking signal strength. The phase resonance is qualitatively reproduced using a forced van der Pol-Duffing-Mathieu equation.