Near-infrared Radiation Research Articles

Synergistic photothermal enhancement of the antibacterial activity of fibroin hydrogel by dual-directional crosslink strategy for efficient solar steam generation

Silk fibroin (SF) has attracted wide attention due to its excellent biocompatibility and versatile adjustability. The regeneration and reutilization of silk fibroin can efficiently utilize waste cocoons and silk. However, the regenerated SF hydrogels suffer from inadequate mechanical properties and lack inherent antibacterial capabilities, limiting their application in seawater desalination. This study achieved a novel hydrogel (STS@Fe) with photothermal antimicrobial activity, good mechanical property, and excellent durability using a green dual-directional crosslink and meso-reconstruction strategy. The metal-phenolic networks (MPN) were synthesized utilizing the natural plant polyphenol tannic acid (TA) and Fe3O4 nanoparticles. This research incorporated MPN into dissolved and regenerated silk fibroin and sodium alginate solution, enhanced mechanical properties through cryogenic salt precipitation, and prepared STS@Fe hydrogel. The inherent photothermal properties of Fe3O4 nanoparticles and TA complex, coupled with their synergistic effect under near-infrared radiation, can confer excellent photothermal-enhanced antibacterial activity to the fibroin hydrogel. The tensile strength of STS@Fe hydrogel is enhanced 31 times than that of traditional fibroin hydrogel, and its evaporation rate is 4.77 times higher than that of pure water evaporation. The hydrogel has an efficient seawater desalination rate and outstanding antibacterial properties in real seawater conditions. Moreover, The STS@Fe shows effective treatment capabilities for dyeing wastewater and oily saline water.

Local Exosome Inhibition Potentiates Mild Photothermal Immunotherapy Against Breast Cancer.

Limited immune infiltration within the tumor microenvironment (TME) hampers the efficacy of immune checkpoint blockade (ICB) therapy. To enhance immune infiltration, mild photothermal therapy (PTT) is often combined with immunotherapy. However, the impact of mild PTT on the TME remains unclear. The bioinformatics analyses reveal that mild PTT amplifies immune cell infiltration and stimulates T-cell activity. Notably, it accelerates the release of tumor cell-derived exosomes (TEX) and upregulates PD-L1 expression on both tumor cells and TEX. Consequently, it is proposed that locally inhibiting TEX release is crucial for overcoming the adverse effects of mild PTT, thereby enhancing ICB therapy. Thus, a multi-stage drug delivery system is designed that concurrently delivers photosensitizers (reduced graphene oxide nanosheets, NRGO), anti-PD-L1 antibodies, and exosome inhibitors (sulfisoxazole). The system employs a temperature-sensitive lipid gel as the primary carrier, with NRGO serving as a secondary carrier that supports photothermal conversion and incorporation of sulfisoxazole. Importantly, controlled drug release is achieved using near-infrared radiation. The findings indicate that this local combination therapy remodels the immunosuppressive TME through exosome inhibition and enhanced immune cell infiltration, while also boosting T-cell activity to trigger systemic antitumor immunity, showcasing the remarkable efficacy of this combination strategy in eradicating cold tumors.

Adhesive, Stretchable, and Photothermal Antibacterial Hydrogel Dressings for Wound Healing of Infected Skin Burn at Joints.

Dressings for infectious skin burn wounds at joints should have therapeutic functions as well as high tissue-adhesion, stretching, and self-healing properties. This makes it difficult for most hydrogel dressings to simultaneously meet the above-mentioned requirements. In this study, poly(vinyl alcohol), anhydrous sodium borax, epigallocatechin gallate, and copper chloride were used to prepare a hydrogel dressing (PBEC) for the infected burn wound healing at joints. The PBEC hydrogel can adhere to a variety of substrates, has a stretching capacity, and quickly self-healing after being damaged. Additionally, the PBEC hydrogel has the properties of reactive oxygen species scavenging, photothermal sterilization, hemostatic ability, and biocompatibility. Finally, the hydrogel could accelerate the process of wound healing in vivo, especially with the assistance of near-infrared radiation. Therefore, the hydrogel dressing shows great potential for clinical application in the healing of infected burn wounds at joints.

Alginate-based functionalized, remote, light-responsive hydrogel transducer for synergistic mild photo thermoelectric stimulation for tumor therapy

Photothermal therapy (PTT) is an effective cancer treatment that circumvents the resistance caused by chemotherapy drugs. Conventional PTT has a relatively high temperature, which is better able to kill tumor tissues, but it is also more damaging to normal tissues. Mild PTT avoids these high temperatures, but its corresponding killing ability becomes lower and enhances the heat resistance of cancer cells, causing tumor self-protection and reducing the therapeutic effect of PTT. Here, we reported a new, remotely stimulable, mild-temperature PTT combined with electrical stimulation-induced ionic interference therapy. We introduced MXenes into alginate based thermoresponsive PVA/P(NIPAm-co-SA) hydrogel (PPS) to formulate mechanically reliable hydrogel electrolyte-based supercapacitors as an ion homeostasis perturbator. The artificially controlled duration of near-infrared radiation modulates the PTT cycle temperature, which is controllably maintained at a little under 45 °C to reduce Hsp90 overexpression. Light-induced phase transitions in the hydrogel produce voltages that resemble low-intensity, alternating electric fields. Moreover, chronic piezoelectric stimulation can inhibit cancer cell proliferation by upregulating the expression of genes encoding Kir3.2 inwardly rectifying potassium channels, by interfering with Ca2+ homeostasis, and by affecting mitotic spindle organization during mitosis. In vivo and in vitro antitumor studies on the 4T1 model suggest that this functionalized, remote, light-responsive transducer is an effective and promising tool for the treatment of tumors.

Spectrum Broadening Due to Nonselective Linear Absorption

The position and linewidth of an emission spectrum reflect the physical properties of the luminophor. So, keeping the spectrum from distortion is very important in its measurement. However, we find that the spectrum linewidth will be broadened when the near-infrared radiation from a sodium lamp passes through a nonselective linear absorbing filter. This counterintuitive linewidth-broadening phenomenon is obvious when the residual light power after the filter is low enough, typically lower than 2.48×10−4 μW. This novel linewidth-broadening effect is different from the well-known Lorentzian, Doppler, and Voigt broadening, and is likely to be more independent evidence of the discrete wavelet structure of classical plane light waves. The effect is significant in high-sensitivity spectroscopy measurements, for example streak camera spectroscopy and Raman spectroscopy experiments. In addition, this effect may also be significant for cosmological research.

Exosome-decorated bio-heterojunctions reduce heat and ROS transfer distance for boosted antibacterial and tumor therapy

Photothermal and photodynamic therapies represent effective modalities for combatting bacteria and tumor cells. However, therapeutic outcomes are constrained by limitations related to the heat and reactive oxygen species (ROS) transfer distance from photosensitizers to targets. To address this issue, we have devised and developed exosome-decorated bio-heterojunctions (E-bioHJ) consisted of MXene (Ti3C2), liquid metal (LM) and exosomes sourced from CT26 cells to enhance the phototherapeutic consequences. Engineering E-bioHJ enhances phototherapeutic effect in antibacterial and anti-tumor treatment, which is ascribed to reducing transfer distance of the heat and ROS. When adorned with exosomes, E-bioHJ is targetedly delivered into the cytoplasm of tumor cells to generate amount heat and ROS under 808 nm near-infrared radiation, which further induces mitochondrial dysfunction and apoptosis/necroptosis. As envisaged, this study presents a novel tactic to enhance the antibacterial and anti-tumor efficacy of biomaterials through reducing the heat and ROS delivery travel distance.

A Study of the Optical Properties and Stability of Cs0.33WO3 with Different Particle Sizes for Energy-Efficient Window Films in Building Glazing

Cs0.33WO3 (CWO) is a widely used inorganic material in window films and glass coatings, known for its excellent near-infrared radiation (NIR) blocking property and high visible light transmittance (Tvis). However, the stability of NIR blocking and the optical properties of CWO in the process of application is an urgent and important problem, because significant changes in optical results can impact the related products, such as window films, glass coatings, and so on. In this paper, the particle sizes and optical properties of CWO are tested to study the light stability and their relative relations. The results indicate that CWO particle sizes between 130 nm and 100 nm (D90, the point where 90% of the particles have a diameter smaller than the specified value) exhibit high stability in terms of NIR blocking and visible light transmittance (Tvis). CWO particles with D90 < 100 nm experience a greater reduction in NIR blocking, though this ability significantly recovers upon exposure to sunlight, making these coatings particularly suitable for use in tropical and subtropical climates.

Effect of Atmospheric Mixing on Spectral Reflectivity in Sentinel Images of Baghdad Province

The lowest layer of the atmosphere is called the atmospheric mixed layer, characterized by small-scale, irregular air motions defined by winds that change in speed and direction. Aerosol radiative effects impact the atmospheric boundary layer (ABL), which holds most aerosols in the lower atmosphere. Aerosol absorption and scattering both lower the quantity of solar energy that reaches the ground, which has an impact on the spectral signature of the land coverings. In this study, 51 locations in downtown Baghdad were chosen for four different types of land cover (water bodies, farms, open areas, and residential areas) for Sentinel 2 satellite imagery, and the time the pictures were taken was 8:00 am ( 22 March, 22 June, 20 September, and 22 December) 2021. Their spectral reflectance was calculated at the NIR band using a mathematical equation in the ArcGIS program for Sentinel 2 satellite images that had been processed and analyzed. Also, atmospheric boundary layer height and solar radiation values were downloaded for the same date as the satellite images and compared with the spectral reflectivity values of the land covers(agriculture area, residential area, open area, and river) and knowing the effect of the mixing layer and solar radiation on the spectral reflectance values. The highest value of spectral reflectivity, mixing layer height, and solar radiation was in June at (0.065, 1965.524629, and 897.7088) respectively. The spectral reflectivity of plants at near-infrared (NIR) was higher than the rest of the earth’s features because plants reflect near-infrared radiation and absorb the red and blue parts of the spectrum.

Synergistic bactericidal effect of antimicrobial peptides and copper sulfide-loaded zeolitic imidazolate framework-8 nanoparticles with photothermal therapy

Antimicrobial resistance (AMR) has emerged as a significant threat to human health. Antimicrobial peptides (AMPs) have proven to be an effective strategy against antibiotic-resistant bacteria, given their capacity to swiftly disrupt microorganism membranes and alter cell morphology. A common limitation, however, lies in the inherent toxicity of many AMPs and their vulnerability to protease degradation within the body. Photothermal therapy (PTT) stands out as a widely utilized approach in combating antibiotic-resistant bacterial infections, boasting high efficiency and non-invasive benefits. To enhance the stability and antibacterial efficacy of AMPs, a novel approach involving the combination of AMPs and PTT has been proposed. This study focuses on the encapsulation of At10 (an AMP designed by our group), and copper sulfide nanoparticles (CuS NPs) within zeolitic imidazolate framework-8 (ZIF-8) to form nanocomposites (At10/CuS@ZIF-8). The encapsulated CuS NPs exhibit notable photothermal properties upon exposure to near-infrared radiation. This induces the cleavage of ZIF-8, facilitating the release of At10, which effectively targets bacterial membranes to exert its antibacterial effects. Bacteria treated with At10/CuS@ZIF-8 under light radiation exhibited not only membrane folding and intracellular matrix outflow but also bacterial fracture. This synergistic antibacterial strategy, integrating the unique properties of AMPs, CuS NPs, and pH responsiveness of ZIF-8, holds promising potential for widespread application in the treatment of bacterial infections.

Process Developments in Electron-Beam Powder Bed Fusion Enabled by Near-Infrared Radiation

The use of an electron beam (EB) as a heating source in EB-based powder bed fusion (PBF-EB) has several limitations, such as reduced powder recyclability, short machine service intervals, difficulties with heating large areas and the limited processability of charge-sensitive powders. Near-infrared (NIR) heating was recently introduced as a feasible replacement and/or complement to EB heating in PBF-EB. This work further investigates the feasibility of using NIR to eliminate the need for a build platform as well as to enable easier repairing of parts in PBF-EB. NIR-assisted Ti-6Al-4V builds were successfully carried out by starting from a loose powder bed without using a build platform. The results do not only confirm that it is possible to eliminate the build platform by the aid of NIR, but also that it can be beneficial for the process cleanliness and improve the surface quality of built parts. Furthermore, a 430 stainless-steel (SS) component could be repaired by positioning it in a loose 316L SS powder bed using a fully NIR-heated PBF-EB process.

Spatiotemporal Delivery of Dual Nanobodies by Engineered Probiotics to Reverse Tumor Immunosuppression via Targeting Tumor-Derived Exosomes.

The anti-PD-L1 and its bispecific antibodies have exhibited durable antitumor immunity but still elicit immunosuppression mainly caused by tumor-derived exosomes (TDEs), leading to difficulty in clinical transformation. Herein, engineered Escherichia coli Nissle 1917 (EcN) coexpressing anti-PD-L1 and anti-CD9 nanobodies (EcN-Nb) are developed and decorated with zinc-based metal-organic frameworks (MOFs) loaded with indocyanine green (ICG), to generate EcN-Nb-ZIF-8CHO-ICG (ENZC) for spatiotemporal lysis of bacteria for immunotherapy. The tumor-homing hybrid system can specifically release nanobodies in response to near-infrared (NIR) radiation, thereby targeting TDEs and changing their biological distribution, remodeling tumor-associated macrophages to M1 states, activating more effective and cytotoxic T lymphocytes, and finally, leading to the inhibition of tumor proliferation and metastasis. Altogether, the microfluidic-enabled MOF-modified engineered probiotics target TDEs and activate the antitumor immune response in a spatiotemporally manipulated manner, offering promising TDE-targeted immune therapy.

Laser powder bed fusion of pure copper using ring-shaped beam profiles

Additive manufacturing of copper using laser powder bed fusion (PBF-LB/M) enables the production of highly complex components. However, processing of copper by means of near-infrared laser radiation is challenging due to its absorptivity of only 5%–20%. Using a keyhole welding process with a Gaussian intensity distribution increases the absorptivity up to 53% due to multireflection. This enables the production of components with a density larger than 99.5% and electrical conductivity larger than 90% of the International Annealed Copper Standard (IACS), but this type of welding leads to keyhole porosity due to keyhole instabilities. One way of counteracting is the use of a heat conduction welding process. However, due to the Gaussian intensity distribution, it is not possible to supply sufficient energy to eliminate lack-of-fusion porosity and concurrently avoid the formation of a keyhole. Ring-shaped beam profiles have proven their advantages in stabilizing the PBF-LB/M process with a tendency toward higher laser power, but pure copper has not yet been processed in this way. Therefore, this study investigates the potential of three ring-shaped beam profiles to produce specimens with a density of more than 99.5% and their respective electrical conductivity using a laser power of up to 1300 W. In order to understand the underlying welding process, the weld geometry of single-tracks is analyzed. Specimens with a density of up to 99.77% and an electrical conductivity of up to 101.62% IACS are produced, whereby the material properties and welding regime depend on the selected ring-shaped beam profile.

Dual motion principal Au-Ni-PDA-CuS micromotors with NIR light and magnetic effect for detection of organic dye

Copper sulfide (CuS), despite some disadvantages such as rapid recombination, easy aggregation, photodegradation of oxidized CuS, and a limited ability to absorb light energy, is still a good photocatalyst. This semiconductor material with a narrow bandgap plays a significant role in the degradation of organic dyes. However, due to these mentioned drawbacks, it requires a linker. The polymer used as this intermediate binder is polydopamine (PDA). PDA not only eliminates the disadvantages of CuS but also facilitates its attachment to the carrier system, which is a micromotor. However, the purpose of using PDA here is not only to eliminate the disadvantages of CuS but also to enable light-triggered motion due to its sensitivity to near-infrared (NIR) radiation. Similarly, CuS, which is a good catalyst, has been used in the polymerization reaction to catalyze dopamine’s conversion to PDA. The micromotor used in the study, based on the dual-motion principle, exhibits high stability and good reusability. The synthesized Au-Ni-PDA-CuS composite micromotor demonstrates a good photocatalytic degradation performance under NIR irradiation. The degradation efficiency is 54.48% at the lowest concentration, while it is 17.72% at the highest concentration, indicating the effectiveness of the synthesized micromotors in achieving good photocatalytic degradation at low concentrations. As a result of the photocatalytic degradation reaction, cyclic voltammetry was performed for 100 cycles to demonstrate the stability of the micromotors.This study is based on the electrochemical method for the photocatalytic degradation of methyl red (MR), an azo dye, using micromotors with a dual-motion principle. Following the development on an azo dye, this study applied the same procedure on real samples, and through in vitro investigation, the photocatalytic degradation of the composite motor on real samples was observed electrochemically.

Ultrabroad Near Infrared Emitting Perovskites.

Phosphor converted light emitting diodes (pc-LEDs) have revolutionized solid-state white lighting by replacing energy-inefficient filament-based incandescent lamps. However, such a pc-LED emitting ultrabroad near-infrared (NIR) radiations still remains a challenge, primarily because of the lack of ultrabroad NIR emitting phosphors. To address this issue, we have prepared 2.5 % W4+-doped and 2.8 % Mo4+-doped Cs2Na0.95Ag0.05BiCl6 perovskites emitting ultrabroad NIR radiation with unprecedented spectral widths of 434 and 468 nm, respectively. Upon band-edge excitation, the soft lattice of the host exhibits broad self-trapped exciton (STE) emission covering NIR-I (700 nm), which then nonradiatively excites the dopants. The -donor ligand Cl- reduces the energy of dopant d-d transitions emitting NIR-II with a peak at ~950 nm. Vibronic coupling broadens the dopant emission. The large spin-orbit coupling and local structural distortion might possibly enhance the dopant emission intensity, leading to an overall NIR photoluminescence quantum yield ~40 %. The composite of our ultrabroad NIR phosphors with biodegradable polymer polylactic acid could be processed into free-standing films and 3D printed structures. Large (170 170 ), robust, and thermally stable 3D printed pc-LED panels emit ultrabroad NIR radiation, demonstrating NIR imaging applications.

Ultrabroad Near Infrared Emitting Perovskites

Phosphor converted light emitting diodes (pc‐LEDs) have revolutionized solid‐state white lighting by replacing energy‐inefficient filament‐based incandescent lamps. However, such a pc‐LED emitting ultrabroad near‐infrared (NIR) radiations still remains a challenge, primarily because of the lack of ultrabroad NIR emitting phosphors. To address this issue, we have prepared 2.5% W4+‐doped and 2.8% Mo4+‐doped Cs2Na0.95Ag0.05BiCl6 perovskites emitting ultrabroad NIR radiation with unprecedented spectral widths of 434 and 468 nm, respectively. Upon band‐edge excitation, the soft lattice of the host exhibits broad self‐trapped exciton (STE) emission covering NIR‐I (680 nm), which then nonradiatively excites the dopants. The π‐donor ligand Cl⁻ reduces the energy of dopant d‐d transitions emitting NIR‐II with a peak at ~950 nm. Vibronic coupling broadens the dopant emission. The large spin‐orbit coupling and local structural distortion might possibly enhance the dopant emission intensity, leading to an overall NIR photoluminescence quantum yield ~40%. The composite of our ultrabroad NIR phosphors with biodegradable polymer polylactic acid could be processed into free‐standing films and 3D printed structures. Large (170 × 170 mm2), robust, and thermally stable 3D printed pc‐LED panels emit ultrabroad NIR radiation, demonstrating NIR imaging applications.

Influence of Sodium Ions and Carbon Black on the Formation and Structural Color of Photonic Balls by Silica Particles.

In this study, photonic balls─spherical aggregates of submicrometer-sized silica particles with uniform particle size─were investigated as structural colored materials. The structural color of these photonic balls is influenced by the ordered arrangement of the silica particles. The research focused on how the addition of electrolytes, specifically NaCl, affects the formation of photonic balls to achieve the desired structural color. Without NaCl, the photonic balls formed onion-shaped colloidal crystals. At NaCl concentrations above 0.006 mol/L, the particles aggregated into short-range ordered structures. When the concentration exceeded 0.05 mol/L, the aggregates lost their spherical shape. The study also explored the addition of carbon black (CB), a water-dispersible material due to its surface charge. The findings revealed that NaCl induced the phase separation between the charged silica particles and CB, resulting in Janus-shaped photonic balls─one side exhibiting structural color and the other side appearing black due to the presence of CB. Changing the silica particle size altered the hues of these Janus-shaped photonic balls, though they appeared uniformly colored to the naked eye. While this study did not specifically examine the applications of Janus-shaped photonic balls composed of silica particles and CB, CB is known for its ability to absorb near-infrared radiation and convert it into heat as well as its conductive properties. Silica, on the other hand, has a low thermal conductivity and acts as an electrical insulator. The structurally colored Janus-shaped photonic balls created in this study may serve as pigments in applications requiring anisotropic heat generation and electrical conduction. Additionally, the study's findings suggest the potential for creating various types of Janus-shaped photonic balls from materials with differing densities.

Synthesis, characterization, and optimization of dual‐responsivePAMAMnanodendrimers for improved dispersive solid‐phase extraction of cancer agents from complex biological samples

AbstractLevels of anticancer agents in cancer patients' body fluids are typically measured to adjust drug dosages or improve treatment results. The goal of this research is to present a new method for extracting bicalutamide (BCT) from biological samples using a responsive polymeric nanoadsorbent that reacts to temperature and near‐infrared radiation (NIR). To achieve this, the surface layers of tungsten disulfide nanosheets are modified using poly (N‐vinylcaprolactam) and three generations of polymeric dendrimers. The adsorbent product is then characterized using thermogravimetric analysis, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, and X‐ray diffraction techniques. The drug loading operation on the proposed adsorbent is studied through central composite design and response surface strategy, with optimization for temperature (25–45°C), pH (5–9), and contact time (2–18 min). Nonlinear kinetic and adsorption isotherm analysis results show the best fit with Langmuir and pseudo‐second‐order models. The drug release process from the BCT‐loaded adsorbent is investigated via an HPLC‐UV system under both NIR‐irradiated and non‐irradiated conditions. The suggested method demonstrates remarkable recovery rates for BCT spikes from urine (95.23%) and plasma (93.33%), respectively. Overall, the recommended strategy can be regarded as a potent analytical tool for evaluating BCT in complex biosamples.

Nanocarrier-based drug delivery system with dual targeting and NIR/pH response for synergistic treatment of oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is highly heterogeneous and aggressive, but therapies based on single-targeted nanoparticles frequently address these tumors as a single illness. To achieve more efficient drug transport, it is crucial to develop nanodrug-carrying systems that simultaneously target two or more cancer biomarkers. In addition, combining chemotherapy with near-infrared (NIR) light-mediated thermotherapy allows the thermal ablation of local malignancies via photothermal therapy (PTT), and triggers drug release to improve chemosensitivity. Thus, a novel dual-targeted nano-loading system, DOX@GO-HA-HN-1 (GHHD), was created for synergistic chemotherapy and PTT by the co-modification of carboxylated graphene oxide (GO) with hyaluronic acid (HA) and HN-1 peptide and loading with the anticancer drug doxorubicin (DOX). Targeted delivery using GHHD was shown to be superior to single-targeted nanoparticle delivery. NIR radiation will encourage the absorption of GHHD by tumor cells and cause the site-specific release of DOX in conjunction with the acidic microenvironment of the tumor. In addition, chemo-photothermal combination therapy for cancer treatment was realized by causing cell apoptosis under the irradiation of 808-nm laser. In summary, the application of GHHD to chemotherapy combined with photothermal therapy for OSCC is shown to have important potential as a means of combatting the low accumulation of single chemotherapeutic agents in tumors and drug resistance generated by single therapeutic means, enhancing therapeutic efficacy.

Near-Infrared On-Site Evaluation (NOSE) Examination of EBUS/EUSb Samples-A New Method for Sample Adequacy Evaluation.

Fine-needle aspiration biopsy is crucial for modern diagnostics of endoscopic procedures and thus an efficient and reliable method for increasing biopsy yields is urgently needed. In our study, we address the limited availability and high price of the rapid onsite evaluation (ROSE) technique by introducing the technique of near-infrared on-site evaluation (NOSE) consisting of spectral measurement of near-infrared radiation (NIR) transmitted through the evaluated material. For this purpose, we designed a special optical probe consisting of two fibres, of which one is a source fibre and the second is a detector fibre. The distal ends of both fibres are brought together into one bundle which is, with the help of a special extension, applied to a cuvette with an analysed sample at a defined distance from the cuvette bottom and fixed in place. A portion of the NIR radiation received by the detector fibre after it propagates through the sample then depends on the optical and therefore morphological characteristics of the sample. Based on the measured spectral curve, we can calculate the attenuation coefficient curve and subsequently the parameter of the sample richness and the parameter characterising the autofluorescence peak as well. We found that the value of our introduced parameters is in significant relation to sample richness as well as to sample malignity. NOSE evaluation of EBUS/EUSb (endobronchial/oesophageal ultrasound bronchoscopy) specimens can be considered an easy new technique aiming to improve sampling diagnostic accuracy and to diminish costs related to the presence of a cytopathologist and related instrumentation in the endoscopy suite.

A near-infrared metastructure to realizing polarization conversion and sensing based on the electromagnetic induced reflection

A multifunctional metastructure (MS) working in the near-infrared band is proposed that achieves linear to circular polarization conversion (LTCPC) and electromagnetically induced reflection (EIR). In addition, due to the use of reflected electric fields to overcome the influences of near-infrared band thermal radiation, MS has a good multifunctional sensing detection. The given MS is composed of a four-layer stacked structure. From the substrate to the top layer (along the +z-direction), it consists of silver, a silicon dioxide layer, and two layers of silicon (Si) resonators. Each layer of the Si resonator has four holes created by rotation. By breaking the symmetry of the upper and lower Si layers of MS, the deviation of the rotation angle of the upper and lower holes is introduced, so the MS achieved a near-infrared EIR with an ultrahigh quality factor (Q-factor). Under electromagnetic wave incidence, at 187.89 THz, the Q-factor of MS's reflection peak reaches 2441.25. Due to the unique shapes of the two resonator layers' holes, the axial ratio (AR) is less than 3 dB between 187.844 THz and 187.871 THz, realizing LTCPC. Utilizing the relationship between the optimal polarization conversion frequency point (the frequency corresponding to the lowest AR) and the environmental refractive index, the MS can be used for detecting cancer cells with a sensing sensitivity (S) of 37.24 THz/RIU (36.06 THz/RIU). By introducing the alcohol into the MS, the refractive index of the alcohol to be measured. MS achieved the detection function of the alcohol solution volume fraction, with an S reaching 33.32 THz/RIU, and a figure of merit as high as 154.202. Finally, the related parameters and polarization angle are discussed. The effects of different parameters on EIR and AR also are analyzed. The innovation of this paper lies in the realization of EIR, and a method to improve the Q-factor of near-infrared EIR by rotating the structure is proposed. The combination of a high Q-factor and polarization conversion overcomes the disadvantage that both are difficult to achieve together, and the EIR is easier to detect than the electromagnetically induced transparency. The design also has potential applications in biomedical sensors and industrial production.