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Single crystals of Thiourea Cadmium hydrogen borate (TCHB), a hybrid nonlinear optical (NLO) material, are grown from an aqueous solution by slow evaporation solution growth technique at ambient temperature. Characterization studies have been conducted to probe the nonlinear effects of the crystal. The crystalline nature of TCHB is explored using the single crystal X-ray diffraction technique. The chemical composition is resolved by the Fourier transform infrared (FTIR) spectroscopy and energy dispersive X-ray analysis. UV–Vis spectral studies analyze the transparency of the crystal. Optical studies illustrate the UV cut-off wavelength to be 285 nm with wide window of transparency in the infrared and visible regions. The optical and electrical conductivity studies indicate superior optical response essential for optical computing and photonic applications. The Kurtz powder test has confirmed the NLO capability. The thermal stability is analyzed through a thermogravimetric study. Dielectric and AC conductivity measurements carried out over a wide range of frequencies (100 Hz to 5 MHz) for various temperatures establish the semiconducting and photonic capacity of TCBH crystal to be used as photodiodes, optical fibres and laser lights. [ABSTRACT FROM AUTHOR]

Objective: The aim of this in vitro experimental series was to explore the mode of action of a hydrocellular polyurethane foam dressing (HPFD) and how its advanced features support beneficial interactions with the wound bed to address common barriers to wound healing, thus supporting improved clinical outcomes. Method: Multiple in vitro microbiological tests were performed, assessing prevention of bacterial ingress, surface removal of bacteria, bacterial sequestration and retention into the dressing in a clinically relevant environment. Odour molecule concentrations were measured using gas chromatography and further assays explored matrix metalloproteinase (MMP)-9 retention in the dressing using enzyme linked immunosorbent assay. Results: The HPFD demonstrated marked reductions in bioburden levels across multiple tests. These included prevention of bacterial ingress for seven days, removal of surface bacteria and absorption into the dressing. Further tests identified that most bacteria were sequestered into the hyperabsorbent layer (90.5% for Pseudomonas aeruginosa and 89.6% for meticillin-resistant Staphylococcus aureus). Moreover, the majority of bacteria (99.99% for both test organisms) were retained within the dressing, even upon compression. Additional tests demonstrated a marked reduction of odour molecules following incubation with HPFD and total retention of protease MMP-9 within the dressing. Conclusions: Proactive management of the wound environment with an appropriate advanced wound dressing, such as the HPFD examined in these in vitro investigations, can not only help to minimise the barriers to healing, as observed across this test series by direct interaction with the wound bed, but may, as a result, provide an ideal environment for wound progression with minimal disturbance. [ABSTRACT FROM AUTHOR]

Objectives. Addressing the prevalent issue of size misfits in large-scale issued firefighter uniforms due to diverse and complex body morphologies, this article presents an objective method for intelligent garment sizing matching without subjective weighting. Methods. The method employs criteria importance through inter-criteria correlation (CRITIC) and the catastrophe progression method (CPM) for more accurate and reliable sizing. Traditional methods, reliant on limited indicators such as height and chest girth and often subjectively determined by experts, are prone to reliability concerns. Matching decisions made based on our approach are evidence-based, transparent and reproducible, thus minimizing subjectivity and expert intervention. Results. A case study of 388 cases validates the method's efficacy in providing garment size recommendations, surpassing traditional experience-based approaches by reducing subjective bias. Conclusion. Despite some differences, the optimal alternatives for examinees are almost consistent across the different methods. Compared with traditional subjective weighting methods, this method has potential advantages in situations such as large-scale matching of firefighter protective clothing where individual customization or direct try-on is not feasible. [ABSTRACT FROM AUTHOR]

Optical materials with non‐π‐conjugated units usually can exhibit large bandgaps, which are conducive to a wide ultraviolet (UV) transparency window. However, the relatively small structural anisotropy hinders the application of these materials as nonlinear optical (NLO) and birefringent materials. Herein, a universal strategy of dissimilating non‐π‐conjugated units is proposed to enhance birefringence, optimize phase‐matching (PM) wavelength, and maintain a large bandgap. The functionality of the series of hetero‐anionic units is distinguished in terms of optimizing birefringence and PM wavelength. In particular, the dimeric hetero‐anionic unit N(SO2F)2− with the dual‐heteroatom dissimilation is found to be a novel superior optical hereto‐gene. In addition, AN(SO2F)2 (A = Li, Na‐I, K‐I/II, H) and Ba(SO3CF3)2 are identified with large birefringence of approximately 0.051–0.106 at 546 nm, which are much larger than those of corresponding sulfates. HN(SO2F)2 exhibits a short PM wavelength (208 nm), a large NLO coefficient (≈ 2 × KDP), and an extremely short UV cutoff edge (149 nm). Experimental polarizing microscope measurement confirms that the birefringence of Pbca‐KN(SO2F)2 is significantly enhanced to 0.06 at 546.1 nm, which is 12 times higher than that of K2SO4. Finally, this strategy offers direction for the design and synthesis of novel NLO or birefringent materials in the future. [ABSTRACT FROM AUTHOR]

We explore novel optomechanically induced transparency (OMIT) and prolonged slow light in a linear and quadratic optomechanical system (OMS) with the Coulomb coupling. The hybrid OMS includes a Fabry–Pérot cavity and two charged mechanical resonators (MR1 inside the cavity and MR2 outside the cavity), where the interaction between the charged MR1 and the cavity field are both linear and quadratic in the MR1's displacement, and the charged MR1 and the charged MR2 mutually coupled via Coulomb interaction. Specifically, the transmission of the output field exhibits three transparency window dips. The Coulomb coupling strength is responsible for creating two transparency window dips near δ / ω m = 1 , which results from the mechanical dressed mode. Simultaneously, the quadratic coupling between the charged MR1 and the optical cavity field significantly contributes to another transparency window dip near δ / ω m = 2 , which is attributed to the two-phonon process. In addition, by adjusting the value of Coulomb coupling strength, linear (quadratic) coupling and frequency of the two mechanical resonators, one can attain prolonged slow light with a group delay extending to tens of milliseconds. Furthermore, the positive (negative) value of quadratic coupling strength can determine the switching behavior of the group delay (i.e., from superluminal to subluminal propagation) on the right (left) side of δ / ω m = 2 . We believe that the results have potential applications in manipulating the performance of OMIT devices and optical switching. [ABSTRACT FROM AUTHOR]

Current trends in the development of materials for optics and laser technology were analyzed. The prospects of creating passively Q-switched Yb-Er glass lasers with eye-safe emission wavelengths based on glass-ceramic magnesium aluminosilicate materials for compact pulsed lasers were established. The main types of transparent glass-ceramic materials were analyzed and the main criteria for the synthesis of transparent nanostructured glass-ceramic materials with a crystalline phase content of approximately 70-80 vol.% were substantiated. Compositions of magnesium aluminosilicate glasses were synthesized and the differences of compositions with different types of optical transparency were determined, taking into account their thermal prehistory. The mechanism of phase formation and the differences of ΣMgO, Al2O3, MgO/Al2O3 and ΣRO2 in their composition, which determine the character of crystallization, optical transparency and density under the conditions of heat treatment with a duration of 0.5 and 6 hours, were studied. The developed magnesium aluminosilicate glasses can be used as a basis for the creation of protective and functional high-strength nanostructured glass-ceramic materials based on spinel or cordierite with adjustable optical transparency for optics and laser technology. [ABSTRACT FROM AUTHOR]

Negative pressure wound therapy is currently one of the most popular treatment approaches that provide a series of benefits to facilitate healing, including increased local blood perfusion with reduced localized oedema and control of wound exudate. The porous foam dressing is a critical element in the application of this therapy and its choice is based on its ability to manage exudate. Industry standards often employ aqueous solutions devoid of proteins to assess dressing performance. However, such standardized tests fail to capture the intricate dynamics of real wounds, oversimplifying the evaluation process. This study aims to evaluate the technical characteristics of two different commercial polyurethane foam dressings during negative pressure wound therapy. We introduce an innovative experimental model designed to evaluate the effects of this therapy on foam dressings in the presence of viscous exudates. Our findings reveal a proportional increase in dressing fibre occupancy as pressure intensifies, leading to a reduction in dressing pore size. The tests underscore the pressure system's diminished efficacy in fluid extraction with increasing fluid viscosity. Our discussion points to the need of establishing standardized guidelines for foam dressing selection based on pore size and the necessity of incorporating real biological exudates into industrial standards. [ABSTRACT FROM AUTHOR]

The organic–inorganic hybrid metal halides with chiral structures have attracted great attentions in the field of optoelectronic functional materials, especially for nonlinear optics. To date, second harmonic generation (SHG) properties of several classes of chiral hybrid halides with different metal ions have been reported. However, SHG‐active tin(II)‐based chiral materials are rarely explored, hindering deep understandings of the relationship between their structures and SHG properties. Herein, Sn2+ ions are successfully introduced into chiral hybrid perovskites, and four new species of chiral hybrid perovskites (R/S‐α‐PEA)SnX3 (X = Cl and Br, PEA = phenylethylammonium) are obtained. The as‐grown crystals are in P212121 space group, with highly distorted [SnX6] octahedral units forming 1D chain structures in the lattice, due to the effect of stereochemically active lone pair 5s2 electrons in Sn2+. Such crystals have an SHG response of ≈1.4× Y‐cut α‐quartz for (S‐α‐PEA)SnBr3 and ≈0.9× Y‐cut α‐quartz for (S‐α‐PEA)SnCl3 at 1020 nm excitation, with high polarization ratio of SHG signals as well as wide bandgaps and transparency windows in the meanwhile. This work opens up a new platform for discovering more novel tin(II)‐based chiral perovskites with superior nonlinear optical properties in the future. [ABSTRACT FROM AUTHOR]

The semi-organic nonlinear optical single crystal Bis (L-Tyrosinato) Cupric acetate (BLTC) was synthesized through a slow evaporation process in atmospheric conditions. A single crystal X-ray diffraction analysis of the formed crystal revealed that it is an orthorhombic crystal system with the space group P212121. Additionally, the powder X-ray diffraction patterns and diffracting planes of the BLTC crystal were recorded and identified. Fourier Transform Infrared (FTIR) spectroscopy analysis was used to characterize the formed crystals in order to identify the various vibrational modes caused by the different functional groups present in BLTC. The 1H and 13C NMR spectra were used to examine the crystal's hydrogen and carbon environments. The UV-visible, near-infrared, and photoluminescence (PL) analyses have been used to do optical studies. According to our findings, the material has a decreased cut-off wavelength and a high transparency window, making it suitable for nonlinear optical (NLO) and optoelectronic applications. The BLTC crystal's predicted band gap was found to be 4.1 eV. Thermo gravimetric (TG) and differential thermal analysis (DTA) techniques were used to determine the thermal properties of BLTC. With three different frequencies, the dielectric measurement of the crystal was observed with respect to temperature. An analysis has been done on the harvested crystals mechanical characteristics. In the developed BLTC crystal, morphological changes on the surface are seen. The material's second harmonic generation (SHG) was tested using the Kurtz and Perry powder method, and it was found to be higher than the KDP. [ABSTRACT FROM AUTHOR]

Traditional polarization converters suffer from drawbacks such as significant thickness and high losses, which limit their practical applications. This study introduces a novel metamaterial structure that combines electromagnetically induced transparency (EIT) with linear polarization conversion to overcome these limitations. By harnessing the properties of EIT, this structure achieves low‐loss polarization conversion. The mechanism behind this is the generation of an EIT effect through the coupling of the light and dark modes. Additionally, this study focuses on introducing a slight vertical polarization symmetry disruption and inducing the excitation of small components within the dipole of the EIT structure to achieve close‐to‐complete cross‐polarization conversion. The effect of asymmetry on the polarization conversion rate is also explored. This study offers an innovative approach to designing low‐loss polarization converters utilizing EIT technology. [ABSTRACT FROM AUTHOR]

The ammonia spectrum is revisited in the important 1.6 µm atmospheric transparency window between 5650 and 6350 cm $ ^{-1} $ − 1 on the basis of recently recorded high-resolution Fourier transform spectra. These spectra offer an improved frequency sampling and better traceability of the measurement conditions compared to previously studied Kitt Peak spectra (Cacciani et al. J. Quant Spectrosc Radiat Transf 2021; 258:107334. https://doi.org/10.1016/j.jqsrt.2020.107334). Overall, 4812 $ ^{14} $ 14 NH $ _3 $ 3 lines were measured in the 5650–6350 cm $ ^{-1} $ − 1 region corresponding to 4866 transitions including 2066 new ones compared with our previous study, included in the HITRAN2020 database. The energy of 1023 upper state levels (including 107 new ones) was derived from 2608 assigned transitions. Independently, ammonia spectra recorded in a supersonic jet expansion using a tunable extended cavity diode laser allow us to check the absolute transition energies in the 5980–6080 cm $ ^{-1} $ − 1 range. Accurate jet spectra calibration was achieved using CH $ _4 $ 4 reference line positions known with kHz accuracy. The position agreement with the FTS data is within the $ 4\times 10^{-4} $ 4 × 10 − 4 cm $ ^{-1} $ − 1 uncertainty of the positions measured in the jet expansion. A recommended line list of 5620 transitions is provided for $ ^{14} $ 14 NH $ _3 $ 3 in the considered 5650–6350 cm $ ^{-1} $ − 1 region. [ABSTRACT FROM AUTHOR]

The ammonia spectrum is revisited in the important 1.6 µm atmospheric transparency window between 5650 and 6350 cm $ ^{-1} $ − 1 on the basis of recently recorded high-resolution Fourier transform spectra. These spectra offer an improved frequency sampling and better traceability of the measurement conditions compared to previously studied Kitt Peak spectra (Cacciani et al. J. Quant Spectrosc Radiat Transf 2021; 258:107334. https://doi.org/10.1016/j.jqsrt.2020.107334). Overall, 4812 $ ^{14} $ 14 NH $ _3 $ 3 lines were measured in the 5650–6350 cm $ ^{-1} $ − 1 region corresponding to 4866 transitions including 2066 new ones compared with our previous study, included in the HITRAN2020 database. The energy of 1023 upper state levels (including 107 new ones) was derived from 2608 assigned transitions. Independently, ammonia spectra recorded in a supersonic jet expansion using a tunable extended cavity diode laser allow us to check the absolute transition energies in the 5980–6080 cm $ ^{-1} $ − 1 range. Accurate jet spectra calibration was achieved using CH $ _4 $ 4 reference line positions known with kHz accuracy. The position agreement with the FTS data is within the $ 4\times 10^{-4} $ 4 × 10 − 4 cm $ ^{-1} $ − 1 uncertainty of the positions measured in the jet expansion. A recommended line list of 5620 transitions is provided for $ ^{14} $ 14 NH $ _3 $ 3 in the considered 5650–6350 cm $ ^{-1} $ − 1 region. [ABSTRACT FROM AUTHOR]

Optical properties of transparent windows at high pressures are of essential importance in dynamic experiments. To investigate the effects of plastic deformation-induced defects on optical transparency of MgO single crystals, real-time absorption spectra are measured via impact experiments and fast multi-color pyrometry. Shock pressure ranges from 50 to 132 GPa. Optical transmission histories are measured in each experiment via an on-board light source generated by shock-wave, from which absorption coefficient α is determined as a function of the wavelength λ. The resultant real-time absorption spectrum (α vs λ) peaks around 520 nm (∼ 2.39 eV), which blueshifts with increasing pressure. These featured spectra are possibly attributed to defective absorption at defect-centers (color-centers) in MgO single crystals generated by shock-waves. Plasticity-induced defects are most likely responsible for the decrease in transparency. MgO single crystals are not suited to be used as an optical window for thermometric in the visible light spectrum under shock pressures above 129 GPa. [ABSTRACT FROM AUTHOR]

Numerous studies have been made to design broadband frequency selective rasorber (FSR). However, it is still a challenge to realize optically transparent FSR, due to the difficulty in realizing high transparency, high-quality factor(Q) parallel resonance, and low-Q series resonance simultaneously. Here, we propose a new method to design transparent FSR for the first time. To break through the technical barrier, a thin copper wire with a different configuration method is utilized to design lossy layer, which can realize high transparency, in-band transmission, and out-of-band absorption concurrently. The proposed FSR is configured by cascading a transparent lossy layer above a transparent frequency selective layer with an air space to separate them. We adopt the equivalent circuit model, electric field distribution, and loss distribution to reveal the physical mechanism of the FSR. The simulation results show that the transmission loss is 1 dB at 8.3 GHz, and the reflection amplitude is less than −10 dB in 2.7–8.9 GHz. The FSR can achieve 96.3% optical transparency theoretically. A prototype is fabricated and measured to validate the proposed design. The measured results achieve good agreement with the simulated results. The proposed FSR can act as a stealth radome for transparent components of ships and aircrafts. The application scenarios can be extended to communication and imaging systems. [ABSTRACT FROM AUTHOR]

We investigate the tunable multiple optomechanically induced transparency in a distant electro-optical system. It consists of two distant optomechanical cavities with two optical parametric amplifiers, which are coupled to charged mechanical oscillators by Coulomb interaction. The system displays the phenomena of tunable multiple optomechanically induced transparency. Specifically, the number and the width of the transparency windows can be manipulated by the coupling parameters. It is found that the larger the Coulomb coupling between the two mechanical resonators, and the coupling between the cavities, as well as the parametric gain of the optical parametric amplifier, the wider the transparency windows. Furthermore, we also study the slow/fast light effect associated with the rapid phase dispersion and group delay of the output probe field. Our approach is feasible for controlling multipartite induced transparency, which represents a valuable step toward quantum networks with photonic and phononic circuits. [ABSTRACT FROM AUTHOR]

This article presents the results of evaluating the possibility of conducting radio astronomy studies in the windows of atmospheric transparency ~100, ~230, and ~350 GHz using the optical Big Telescope Alt-Azimuthal (BTA) of the Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS). A list of some promising astronomical tasks is proposed. The astroclimat conditions at the BTA site and possible optical, cryogenic, and mechanical interfaces for mounting a superconducting radio receiver at the focus of the optical telescope are considered. As a receiving system, arrays of detectors cooled to ~0.3 K based on the superconductor–insulator–normal metal–insulator–superconductor (SINIS) structure are proposed. The implementation of the project will make it possible to use the BTA site of the SAO RAS not only to solve some astronomical problems (it is possible to consider the implementation of a single observatory, the VLBI (very-long-baseline interferometry) mode in the Suffa, EHT (Event Horizon Telescope), and Millimetron projects), but it will also be used to test various cryogenic detectors in a real observatory. [ABSTRACT FROM AUTHOR]

Targeted medicine uses the distinctive features of cancer cells to find and destroy tumors. We present human epidermal growth factor receptor 2 (HER2)-targeted PLGA–chitosan nanoparticles for cancer therapy and visualization. Loading with two near-infrared (NIR) dyes provides imaging in the NIR transparency window and phototherapy triggered by 808 nm light. Nile Blue (NB) is a biocompatible solvatochromic NIR dye that serves as an imaging agent. Laser irradiation of IR-780 dye leads to a temperature rise and the generation of reactive oxygen species (ROS). Resonance energy transfer between two dyes allows visualization of tumors in a wide range of visible and IR wavelengths. The combination of two NIR dyes enables the use of nanoparticles for diagnostics only or theranostics. Modification of poly(lactic-co-glycolic acid) (PLGA)–chitosan nanoparticles with trastuzumab provides an efficient nanoparticle uptake by tumor cells and promotes more than sixfold specificity towards HER2-positive cells, leading to a synergistic anticancer effect. We demonstrate optical imaging of the HER2-positive mouse mammary tumor and tumor-specific accumulation of PLGA–IR-780–NB nanoparticles in vivo after intravenous administration. We managed to achieve almost complete suppression of the proliferative activity of cells in vitro by irradiation with an 808 nm laser with a power of 0.27 W for 1 min at a concentration at which nanoparticles are nontoxic to cells in the dark. [ABSTRACT FROM AUTHOR]

Nano‐ and microcrystals of diamond are attractive for optical thermometry applications and possess unique optical properties as well as high chemical stability and biocompatibility. For biological application, there are interests of diamonds with color centers that emit in the biological transparency window. One such defect is nickel‐related color centers that radiate in the near‐infrared range (1.4 eV Ni centers), but have not yet been sufficiently investigated. In this study, the optical characteristics of high‐pressure high‐temperature (HPHT) diamond microcrystals with average sizes of 4 and 30 μm containing 1.4 eV Ni centers are reported. The temperature dependence of the spectral and temporal properties of Ni center emissions in the range from room temperature to 85 °C is demonstrated and thereby the possibility of appliance these centers as temperature sensors. The relative temperature sensitivities of luminescence peak intensity and lifetime for Ni centers are found to be 1.3% K−1 and 0.42% K−1, respectively. Moreover, the temperature determination accuracy reaches better than 1 K. [ABSTRACT FROM AUTHOR]

The optical response in a hybrid optomechanical system containing a triple quantum well (TQW) is investigated theoretically. The optomechanical cavity is driven by a strong pump field and a weak probe field. We show that multiple electromagnetically induced transparency windows and optomechanically induced transparency (OMIT) window exist simultaneously for the weak probe field due to the Jaynes–Cummings coupling and optomechanical coupling respectively. Furthermore, the system absorption spectra can be tuned by changing the system coupling strength. Especially, when two external control lasers are applied to the TQW with frequency detuning, multiple transparency windows can be illustrated and adjusted by the external fields. Therefore, via changing the external coupling fields, we can realize manipulating the OMIT transparency window, tunable group delay and switch from fast light to slow light. Such a system may be much practical for the flexibility of TQW in the quantum information processing. [ABSTRACT FROM AUTHOR]

The studies on family businesses hold significance due to the imperative to understand their historical and current influence on regional and national economies globally. This article aims to identify and characterize governance practices in such businesses and determine their impact on crafting and presenting transparent financial information—a strategy that ensures sustainability. The study defines transparency by weaving in intricate factors of family business and bases its evaluation on management theory contributions and professionalization elements. Such an approach serves as a foundation to bolster the prevailing consolidation trends in these entities. The research adopts a case study methodology combined with a descriptive lens, incorporating fundamental aspects of explanatory and correlational research. Employing Pearson's correlation coefficient helped establish causal relationships and discern the interplay between variables, facilitated by a questionnaire. Analysis unveils a pronounced and contemporary correlation between corporate governance variables and financial transparency. [ABSTRACT FROM AUTHOR]

Superior infrared nonlinear optical (NLO) crystals are in urgent demand in the development of lasers and optical technologies for communications and computing. The critical challenge is to find a crystal with large non‐resonant phase‐matchable NLO coefficients and high laser damage threshold (LDTs) simultaneously, which however scale inversely. This work reports such a material, MgSiP2, that exhibits a large second harmonic generation (SHG) coefficient of d14≈d36 = 89 ± 5 pm V−1 at 1550 nm fundamental wavelength, surpassing the commercial NLO crystals AgGaS2, AgGaSe2, and ZnGeP2. First principles theory reveals the polarizability and geometric arrangement of the [SiP4] tetrahedral units as the origin of this large nonlinear response. Remarkably, it also exhibits a high LDT value of 684 GW cm−2, which is six times larger than ZnGeP2 and three times larger than CdSiP2. It has a wide transparency window of 0.53–10.35 µm, allowing broadband tunability. Further, it is Type I and Type II phase‐matchable with large effective SHG coefficients of deff,I ≈80.2 pm V−1 and deff,II ≈73.4 pm V−1. The outstanding properties of MgSiP2 make it a highly attractive candidate for optical frequency conversion in the infrared. [ABSTRACT FROM AUTHOR]

Dynamic control of probe absorption spectrum via vortex beams in multilevel systems has attracted much attention because it provides an avenue to observe unique transport properties. In this paper, we employ experimentally accessible parameters to flexibly control the probe absorption spectrum that shows vortex-induced transparency (VIT) and absorption (VIA) phenomena. Specifically, this system can be served as an optical switch while the vortex beams can act as the control knob, which has the ability to switch from a transparency dip to an absorption peak. Differing from a conventional electromagnetically induced transparency technique, our proposed scheme investigates VIT and VIA by tuning the orbital angular momentum of vortex beams in the resonance and non-resonance cases. Moreover, the collective feature caused by constructive or destructive interference is also studied via adjustable frequency detuning. Our results may provide an efficient approach to study similar phenomena in multilevel quantum systems driven by optical vortex beams. [ABSTRACT FROM AUTHOR]

This paper studies the effects of five parameters, including fiber diameter, crystallinity, thickness, packing density, and surface roughness, on the transparency of electrospun polymethyl methacrylate/polydimethylsiloxane (PMMA/PDMS) nanofibrous membranes after heat treatment. The PMMA/PDMS membranes produced at an electrospinning voltage of 20 kV reaches 54.85% transparency with the diameter 0.759 µm, crystallinity 14.81%, thickness 9.2 µm, roughness 0.659 µm, and packing density a 0.0081% after the heat treatment from 80 to 200°C. In general, the PMMA/PDMS membranes present higher transparency with the decrease of diameter, crystallinity, thickness, roughness, and packing density. The influencing parameters on transparency are first quantified by multiple nonlinear regressions with a R2 of the model equals 0.869. A composite scaled sensitivity (CSSj) analysis shows that the most influential factor is the nanofibrous membrane thickness with a CSSj value of 1, followed by fiber diameter with a CSSj value of 0.515. The CSSj values for packing density, membrane roughness and crystallinity are 0.385, 0.361, and 0.173, respectively. Finally, the nanofibrous membrane transparency is a function of nanofiber material density, fiber diameter, and nanofibrous membrane thickness based on the Chandrasekhar radiative transfer equation and the Rayleigh's Scattering Theory. [ABSTRACT FROM AUTHOR]

We use electromagnetically induced transparency (EIT) to generate optical switching of the probe laser field according to the pulse modulation of the coupling laser field in a three-level V-type atomic system. When the absence of the coupling laser field, the probe laser field is completely absorbed by the atomic medium at the resonant frequency. However, the probe laser field becomes transparent when the coupling laser field is present. Thus, by turning the coupling laser field ON or OFF, the output signal of the probe laser field is also switched from ON to OFF, and vice versa. To describe this optical switching phenomenon, we derive a set of Maxwell–Bloch equations for the three-level V-type atomic system with laser fields and use a combination of the four-order Runge–Kutta and finite difference numerical methods to simulate the propagation of the probe and coupling laser pulses in the atomic medium. Under the EIT condition, we obtain the optical switching of the probe pulse that modulated according to the coupling pulse. The influence of the switching period as well as the intensity and frequency of the coupling laser field on the optical switching of the probe laser field are also studied. [ABSTRACT FROM AUTHOR]

This case study examines the effectiveness of using negative pressure wound therapy (NPWT) in the management of a hard-to-heal (chronic) wound with exposed ankle bone to reduce associated wound exudate and promote production of granulation tissue. A 60-year-old male patient who was able to attend wound follow-up diligently twice weekly for eight weeks, and weekly thereafter, was selected from a private hospital to take part. During each dressing change, the wound was cleansed with superoxidised cleansing solution, and minimal sharp debridement was performed. In the authors' opinion, the NPWT device used in this study is light and convenient for use in the community or home care setting. The NPWT wound dressing was connected to the NPWT machine via a connecting tube and the device then switched on using the default setting of a negative pressure of 125mmHg. Following the application of the NPWT device, the exposed ankle bone was successfully covered with healthy granulation tissue and healed within 20 weeks with minimal exudate formation in the wound. In the authors' opinion, NPWT is able to promote progress to wound healing; to minimise unnecessary dressing changes and, based on feedback from the patient, is comfortable to wear and when in use. [ABSTRACT FROM AUTHOR]

Agile rf sources are a common requirement for control systems in quantum science and technology platforms. The direct digital synthesizer (DDS) often fills this role by allowing programmable control of the rf signals. Due to limitations of the DDS architecture, implementing an agile rf source requires rapid and precisely-timed programming of discrete updates that restrict the source's agility. Here, we describe a microcontroller-based interface that exploits the DDS's internal linear sweep accumulator to perform both sequential linear sweeps and standard discrete updates at the ∼ 10 μs scale. This allows updates to the swept parameter as fast as every 8 ns with greatly reduced communication and memory overhead. We demonstrate the utility of this system by using it as the reference of an optical phase-locked loop to implement rapid, adjustable laser frequency sweeps in a Rydberg electromagnetically induced transparency spectroscopy measurement. [ABSTRACT FROM AUTHOR]

We investigate theoretically the time dependent fluorescence spectra (TDFS) of a three-level system in electromagnetically induced transparency (EIT) and coherent population trapping (CPT) configurations. Time dependent fluorescence intensities of Rayleigh and Stokes transitions are studied as a function of the ground state coherence relaxation rate and initial state preparation, and their correlation with the temporal evolution of dark and bright states is established. Linewidths of fluorescence and absorption are compared in different regimes of relaxation rates. The results are used to discuss the characteristic features of EIT and CPT in the domain of fluorescence spectroscopy. [ABSTRACT FROM AUTHOR]

A graded buffer Bragg reflector (GBBR) is a bifunctional device component that provides the reflection of a distributed Bragg reflector and the adjustable lattice constant of a compositionally graded buffer. Prior work showed that these properties can be combined with low threading dislocation density and high reflectivity. Here, we design and demonstrate complex GBBRs for specific metamorphic solar cell applications. We design buffers that provide (1) high reflectivity over a narrow bandwidth, for quantum well solar cells, (2) reflectivity over a wide bandwidth, for optically thin solar cells, and (3) low sidelobe reflection, for multijunction devices that demand low out-of-band reflection. Apodized and triple GBBRs are demonstrated, and transparency is always considered, requiring designs with carefully engineered material combinations. A GBBR with a reflection of 99% is demonstrated, as well as a triple GBBR that has over 80% reflection for 100 nm of the spectrum around 800 nm. We also analyze potential deviations in a baseline GBBR from that of a perfect DBR using transmission electron microscopy to analyze imperfections in the material and modeling to analyze the impact of imperfect refractive index data for lattice-mismatched AlGaInAs. Minimal crosshatch roughness and unintentional thickness variation occur throughout the buffer, which likely influences reflection slightly. Small deviations between the calculated AlGaInAs and utilized AlGaAs refractive index exist, giving methods for future GBBR improvement. While the GBBR designs are intended for metamorphic solar cells, the broad and high reflection may also be useful for other optoelectronic devices such as light-emitting diodes or lasers. [ABSTRACT FROM AUTHOR]

The response of a spin exchange relaxation free atomic magnetometer to a repetitive short-pulsed pump was investigated. Quantum sub-resonances at a repetition rate of 1/n of the Larmor frequency of the magnetic field inside the shield are experimentally observed and theoretically explained. This is a type of synchronization phenomenon. Investigations in single alkali atom cells and mixed alkali atoms of K and Rb are presented. In the latter, one species is pumped while the probe is on the other species polarized by spin exchange. The effect of spin destruction, spin exchange, and collisions is studied in order to account for the width of the resonances. Quantum calculations of a three-level Λ model for this phenomenon exhibit a dip at the resonance frequency in the absorption spectrum for both cases of pulsed and cw pump modes and an evidence for electromagnetically induced transparency. [ABSTRACT FROM AUTHOR]

In this paper, two graphene-based all-optical terahertz (THz) modulators are proposed. The operations of the structures are based on high quality factor (Q-factor) resonances in graphene–dielectric metasurfaces. The first modulator is a polarization-dependent metasurface where a sharp resonance is originated from the effect of electromagnetically induced transparency. The structure is analyzed using the finite element method. The modulation is performed by photoexcitation of carriers in graphene by infrared optical pumping. Interestingly, owing to the stimulated emission of THz photons, a high transmission change of more than 120% and a high modulation depth of 93% at the frequency of 5 THz are obtained. The second structure is a polarization-independent modulator that operates based on a high Q-factor Fano resonance in asymmetric dielectric disks. It is presented that a high modulation depth of 98% is achieved. The required optical intensity for both structures is calculated to be as low as 7.35 W/cm2. As the proposed graphene-based metasurfaces are optically tunable, they are promising for the realization of fast and efficient spatial THz modulation. [ABSTRACT FROM AUTHOR]

Transmissibility limitation is one of the most important barriers in the use of windows for shock experiments if optical probes are used. In this article, we focus on the widely used window material lithium fluoride (LiF) and investigate its optical response under laser-induced shock-compression conditions. A long-pulse laser is shaped to create a continuous accelerating shock wave propagating through the LiF window in the range of 100–400 GPa. The variation of measured optical transmission with shock pressure shows that the LiF window stays transparent even when the shock stress is higher than 350 GPa and transforms to a total opaque state at about 400 GPa. The present experiment exhibits an obviously higher shock stress for LiF windows to lose transparency compared with previously reported results. The discrepancy in experimental results is considered to be due to the difference in shock thickness for a typical time scale at different experimental platforms. Meanwhile, the possible reasons for the discrepancy between our experimental data and the previous ab initio calculations can be suggested by the effect of thermal relaxation between electrons and ions or the overestimation of the absorption coefficient in theoretical calculations. This finding of higher transmissibility limitation may be of importance to researchers who use LiF as a window material in future shock-compression experiments, especially at the laser platform. [ABSTRACT FROM AUTHOR]

We present a physical model of laser thermogenetic neurostimulation, which combines radiation- and heat-transfer analysis with thermodynamic treatment of thermosensitive cell-membrane ion channels and the electrophysical description of the neuron response to the thermal gating of ion channels. Based on the analysis performed within the framework of this model, we identify the parameter space within which laser thermogenetic neurostimulation can be confined to a single neuron and show that an accurately dosed nonstationary heat transfer set off by near-infrared laser pulses with a laser wavelength chosen within the transparency window of water, centered at ≈1670 nm, can help extend single-cell thermogenetic neurostimulation to deep brain regions. [ABSTRACT FROM AUTHOR]

Copyright of Enfermería Nefrológica is the property of Sociedad Espanola de Enfermeria Nefrologica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Recent works in metamaterials and transformation optics have demonstrated exotic properties in a number of open systems, including perfect absorption/transmission, electromagnetically induced transparency, cloaking or invisibility, etc. Meanwhile, non-Hermitian physics framework has been developed to describe the properties of open systems, however, most works related to this focus on the eigenstate properties with less attention paid to the reflection characteristics in complex frequency plane, despite the usefulness of zero-reflection (ZR) for applications. Here we demonstrate that the indirectly coupled two-magnon system not only exhibits non-Hermitian eigenmode hybridization, but also ZR states in complex frequency plane. The observed perfect-ZR (PZR) state, i.e., ZR with pure real frequency, is manifested as infinitely narrow reflection dips (~67 dB) with infinite group delay discontinuity. This reflection singularity of PZR distinguishes from the resonant eigenstates but can be adjusted on or off resonance with the eigenstates. Accordingly, the absorption and transmission can be flexibly tuned from nearly full absorption (NFA) to nearly full transmission (NFT) regions. Absorption, transmission and reflection are three processes characterizing optical devices. Absorption allows for signal conversion and transmission is important for signal transfer, however, reflection is frequently detrimental to device performance. Here, Qian et al demonstrate a magnonic device with controllable absorption and transmission while maintain zero reflection. [ABSTRACT FROM AUTHOR]

According to the Babinet principle, the diffraction pattern from an opaque body is identical to that from a hole of the same shape and size. Intuitively, placing two complementary structures such as an opaque metal body and its transparent counterpart one by one may result in destructive or constructive interference leading to unexpected electromagnetic response. We propose a Babinet principle-based metamaterial made of two complementary metal/hole checkerboards. The unit cell of each layer is either a metal square with 1/4 of 8 neighboring squares, four of which are made of metal, whereas the other four are square holes, or vice versa. Being placed complementary at optimal distance equal to three-unit cell length, the compound bi-layered Babinet structure demonstrates absolute transparency in a very broad frequency range. The observed absolute transparency of the bi-layered Babinet metasurface is the result of the modified multipole interaction of layers with shifted centers of radiation. We demonstrate both theoretically and experimentally absolute transmission of 0 dB for the Babinet metamaterial made of 3 cm sized Cu squares and complementary holes in the broad frequency range from 4.5 to 6.62 GHz in simulations and from 4.6 to 6.4 GHz in the experiment when the distance between two layers is 1.2 cm. Moving layers toward each other leads to blurring of the resonances. The proven concept of simple, reproducible, and scalable design of the Babinet metamaterial paves the way for the fabrication of broadband transparent devices at any frequency, including THz and optical ranges. The main advantage of broadband Babine metamaterials is applications in optical switching, sensing, filtering, and slow light devices. [ABSTRACT FROM AUTHOR]

In this paper, we theoretically analyze optically-induced transparency and absorption properties of a weak probe field in a two-mode coupled micro-cavity system and explore the tunable asymmetric Fano line shape of the transmission rates of the probe field. Both the modes in our system consist of an optical Kerr medium, one of them being passive while the other mode can be either active or passive. The forward transmission and backward reflection profile of the probe field are investigated for both passive–passive and passive–active cavity systems by varying different system parameters such as probe field detuning, photon tunneling strength, gain-to-loss ratio, etc. The results of this study have the potential to be applied in construction of quantum telecommunication and photonic devices. [ABSTRACT FROM AUTHOR]

This study examines the field of conservative news nonprofits, using discourse analysis to explore their missions and other public statements. We find that many of these organizations draw on the legitimacy of mainstream journalism outlets while critiquing them, at once associating with and dissociating from them. This enables them to justify their engagement in political activism even as they obscure their ideological orientations and funding sources, behaviors that challenge the normative boundaries of mainstream commercial journalism in the U.S. This work shows how self-described outsiders to a field build and maintain boundaries to legitimate their own work in relation to that field. [ABSTRACT FROM AUTHOR]

The article discusses the crisis of abuses in the Church and the importance of prevention and the implementation of a culture of care and protection. The structural corruption of the Church is criticized and the importance of recognizing negligence and examining the mission in the world is highlighted. The need to not long for the past but to build a future full of promises and hopes is also mentioned. The importance of active participation of the laity in the purification of the Church and communication with the victims to recover the sense of evangelical charity is emphasized. [Extracted from the article]

Introduction: In patients with acute respiratory distress syndrome, prone positioning improves oxygenation and reduces mortality. Pressure injuries occur frequently because of prolonged prone positioning in high-risk patients, and preventive measures are limited. This article describes 2 patients who developed minimal pressure injuries despite several prone positionings. Prevention strategies are also described. Clinical Findings: A 64-year-old man and a 76-year-old woman were admitted to the hospital with respiratory insufficiency. Due to acute respiratory distress syndrome, both patients were intubated and received mechanical ventilation and prone positioning. Diagnosis: Both patients had positive test results for SARS-CoV-2 and a diagnosis of acute respiratory distress syndrome. Interventions: Patient 1 was in prone position for 137 hours during 9 rounds of prone positioning; patient 2, for 99 hours during 6 rounds of prone positioning. The standardized pressure injury prevention bundle for prone positioning consisted of skin care, nipple protection with a multilayer foam dressing, a 2-part prone positioning set, and micropositioning maneuvers. For both patients, 2-cm-thick mixed-porosity polyurethane foam was added between skin and positioning set in the thoracic and pelvic areas and a polyurethane foam cushion was added under the head. Outcomes: Patient 1 developed no pressure injuries. Patient 2 developed category 2 pressure injuries on the chin and above the right eye during deviations from the protocol. Conclusion: For both patients, the additional application of polyurethane foam was effective for preventing pressure injuries. These case reports support the addition of polyurethane foam to prevent pressure injuries in patients placed in the prone position. [ABSTRACT FROM AUTHOR]

Split‐thickness skin grafts (STSG) are widely used in wound reconstruction. However, donor site wounds are created as a result. Traditionally, moist wound healing and transparent film dressings have been used to promote donor site wound healing. This retrospective study evaluated the use of oxidised regenerated cellulose (ORC)/collagen/silver‐ORC dressing (ORC/C/Ag‐ORC) with an absorptive silicone adhesive border dressing and transparent film dressing (treatment) compared with petrolatum‐based gauze dressing (control) over donor site wounds. Patients underwent an STSG procedure between January and December 2020. Donor sites received treatment (n = 10) or control (n = 10) dressings. Dressing changes occurred as necessary. Time to epithelialisation, narcotic pain medication requirements, and the number of office/hospital visits were examined. Twenty patients were managed (9 males, 11 females, average age: 49.7 ± 13.9 y). Patient comorbidities included hypertension, diabetes, and hyperlipidemia. Wound types included traumatic and cancer excision. Time to epithelialisation was significantly reduced in the treatment group (11.1 ± 1.4 d vs 18 ± 2.4 d, P < 0.0001). The number of office visits for dressing changes was significantly lower in the treatment group (0.1 ± 0.3 vs 2 ± 0.7, P < 0.0001). No patients in the treatment group required a hospital visit, compared with 3 patients in the control group. One patient in the treatment group required narcotic pain medication, compared with 5 in the control group. In this patient population, the use of ORC/C/Ag‐ORC, an absorptive silicone adhesive border dressing, and transparent film dressing resulted in a shorter time to epithelialisation and less analgesic requirement compared with petrolatum‐based gauze dressing use. [ABSTRACT FROM AUTHOR]

We attempt to demonstrate optical phase switches in a typical light storage experiment. We computed propagation dynamics of light pulses in sodium-23, rubidium-87, and potassium-39 vapors. These vapors have the same tensorial sets of the density matrix with a nuclear spin I = 3/2. The energy scheme is known as the double-Λ system. We considered an excitation mechanism in which one of two Λ systems was excited by two-color pulses, probe, and drive, following the standard electromagnetically induced transparency configuration. The probe channel contains delayed two pulses after the first probe pulse. Gain is generated through the drive channel and is exposed during propagation. We further investigated the spatiotemporal phase variations in the pulses and found discrete phase distribution for different vapors. The spatiotemporal evolution of the irreducible tensorial sets defines structural differential equations. Additionally, it is particularly suitable for parallel processing. We hope our study finds an application in comparison to alkali vapor magnetometry. [ABSTRACT FROM AUTHOR]

Using Monte Carlo simulation, we studied the electrical conductance of two-dimensional films. The films consisted of a poorly conductive host matrix and highly conductive rodlike fillers (rods). The rods were of various lengths, obeying a log-normal distribution. They were allowed to be aligned along a given direction. The impacts of the length dispersity and the extent of the rod alignment on the insulator-to-conductor phase transition were studied. Two alternative computational approaches were compared. Within Model I, the films were transformed into resistor networks with regular structures and randomly distributed conductances. Within Model II, the films were transformed into resistor networks with irregular structures but with equal conductivities of the conductors. A comparison of the models evidenced similar behavior in both models when the concentration of fillers exceeded the percolation threshold. However, a fairly fine mesh should be used in Model I to obtain a reasonable estimation of the electrical conductance. The electrical conductance is slightly overestimated in Model I. In anisotropic systems, the length dispersity of fillers has a more pronounced effect on the electrical conductance along the direction of the rod alignment. Some analytical results were obtained: (i) the relationship between the number of fillers per unit area and the transmittance of the films within Model I and (ii) the electrical conductance of the films for dense networks within Model II. [ABSTRACT FROM AUTHOR]

The sixth generation (6G) communication will use the terahertz (THz) frequency band, which requires flexible regulation of THz waves. For the conventional metallic metasurface, its electromagnetic properties are hard to be changed once after being fabricated. To enrich the modulation of THz waves, we report an all-optically controlled reconfigurable electromagnetically induced transparency (EIT) effect in the hybrid metasurface integrated with a 10-nm thick MoTe2 film. The experimental results demonstrate that under the excitation of the 800 nm femtosecond laser pulse with pump fluence of 3200 μJ/cm2, the modulation depth of THz transmission amplitude at the EIT window can reach 77%. Moreover, a group delay variation up to 4.6 ps is observed to indicate an actively tunable slow light behavior. The suppression and recovery of the EIT resonance can be accomplished within sub-nanoseconds, enabling an ultrafast THz photo-switching and providing a promising candidate for the on-chip devices of the upcoming 6G communication. [ABSTRACT FROM AUTHOR]

Background: In elderly patients hospitalised in internal medicine departments, risk factors, preferable placement area and methods of securement of short peripheral venous catheters (SPVC) a unclear. Aim: To determine the incidence and risk factors of adverse events using a transparent bordered dressing for securement in the dorsum of the hand or cubital fossa in consecutive patients hospitalised in an internal medicine department. Methods: In a prospective observational study of patients admitted to a regional hospital with a SPVC, the dependent variable was the need to replace the catheter because of an adverse event (phlebitis, accidental removal, infiltration/occlusion). The independent variables were age, gender, disorientation, placement area, intravenous antibiotic therapy and indwelling time. Risk factors were determined by Cox regression model analysis. Results: There were 709 catheters placed in 499 patients. Per catheter placed the mean age was 75 ± 17 years. Accidental removal, infiltration/obstruction and phlebitis occurred in 21.5, 16.2 and 15.0 events per 1000 days respectively. There was a significantly increased risk on Day 3 compared to Days 2 and 4. An older age, intravenous antibiotics and disorientation increased the hazard for accidental displacement, whereas phlebitis was associated only with intravenous antibiotics and occlusion/infiltration only with age. Conclusions: The observed low rates of adverse events suggests that placement in the dorsum of the hand or cubital fossa secured by a transparent dressing is acceptable. It is important to consider the indwelling catheter time when studying adverse events, and elderly patients, disoriented patients and/or patients receiving intravenous antibiotics deserve special attention. [ABSTRACT FROM AUTHOR]

In this study, we use a phase-changing material vanadium dioxide (VO2) to design a multilayer metasurface structure to achieve the transition from an electromagnetically induced transparency(EIT) device to an absorber. The structure consists of a gold layer, a polyimide spacer layer, a VO2 layer, and a sapphire substrate. The top layer consists of one cut wire and two split-ring resonators with the same parameters. When the VO2 layer is in its insulating phase at room temperature, the peak of the EIT device will appear near 1.138 THz. When the VO2 layer is in the metallic state, two absorption peaks above 99.5% appear separately at 1.19 and 1.378 THz, respectively. To the best of our knowledge, this is the first time that a coupled mode equation is used to perform theoretical calculations for EIT devices and perfect absorbers simultaneously, and this is also the first time that coupled mode equations are used for the theoretical calculations of two absorption peaks in an absorber. The proposed metasurface combines the advantages of terahertz absorption, EIT and active device control, which will provide more ideas for the design of future terahertz devices and is also significant for the design and development of radomes for future stealth aircraft. [ABSTRACT FROM AUTHOR]

Supply chains are experiencing significant advances in digital technologies, particularly those associated with industry 4.0. An example of such technology is blockchain. Blockchain is a disruptive technology characterised by anonymity and identity, consensus mechanism, decentralisation, overall performance and expectancy, reliability of systems and data, and information transparency. Blockchain offers supply chain opportunities to strengthen end-to-end visibility and traceability, leading to enhanced levels of transparency. Supply chains are increasingly exploring blockchain technology and transparency, with many focusing on system development. This paper explores transparency in blockchain-based supply chains to understand the principles underlining its design. A systematic review of literature is used, accompanied by data-driven analysis. The results present the principles within a framework for transparency by design in blockchain-based supply chains. Limitations and areas for future work are also presented. [ABSTRACT FROM AUTHOR]

We theoretically investigate tunable double optomechanically induced transparency (OMIT) controlled by an external force exerted on the double cavity optomechanical system. It is shown that this system could manifest single OMIT effect or double OMIT effect by adjusting the external force. More importantly, slow-fast light conversion can be realizable by controlling the external force. The influence of the system parameters such as the coupling strength between the two cavities and the decay rates on the output field is analyzed. This force-induced double transparency could be applicable for further optical manipulation and force-dependent quantum metrology. [ABSTRACT FROM AUTHOR]

Copyright of Moderne Staat is the property of Verlag Barbara Budrich GmbH and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Trauma, burns, and diabetes result in nonhealing wounds that can cause bone or tendon exposure, a significant health threat. The use of an artificial regeneration template combined with skin grafting as an alternative method to highly invasive flap surgery has been shown to be an effective way to cover full‐thickness skin defects with bone or tendon exposure for both functional and aesthetic recovery. However, artificial regeneration templates, such as Pelnac, are overwhelmingly expensive, limiting their clinical use. Here, we demonstrate for the first time that polyurethane film combined with absorbable gelatine sponge, affordable materials widely used for haemostasis, are effective for dermal reconstruction in wounds with bone or tendon exposure. The absorbable gelatine sponge combined with polyurethane film was applied to eight patients, all resulting in adequate granulation that fully covered the exposed bone or tendon. The outcome of absorbable gelatine sponge combined with polyurethane film application indicates that this approach is a potential novel and cost‐effective dermal reconstruction strategy for the treatment of severe wounds with bone or tendon exposure. [ABSTRACT FROM AUTHOR]