bluuebunny/crossref_metadata_2025 huggingface dataset:
Strong Er3+ radiative emission enhancement by quasi-BIC modes coupling in all-dielectric slot nanoantenna arrays
Authors: Kalinic Boris , Cesca Tiziana , Trevisani Mirko , Jacassi Andrea , Sapienza Riccardo , Mattei Giovanni
Published: October 2023

We have designed and realized all-dielectric lossless nanoantennas, in which a thin SiO2 layer doped with erbium ions is placed inside slotted silicon nanopillars arranged in a square array. The modal analysis has evi-denced that the slotted nanopillar array supports optical quasi-BIC resonances with ultra-high Q-factors (up to Q∼109), able to boost the electromagnetic local density of optical states in the optically active layer. Up to 3 orders of magnitude photoluminescence intensity increment and 2 orders of magnitude decay rate enhancement have been measured at room temperature when the Er3+ emission at about λ=1540 nm couples with the quasi-BIC resonances. Furthermore, by tailoring the nanopillar aspect ratio, the slot geometry has been exploited to obtain selective enhancements of the electric or magnetic dipole contribution to Er3+ radiative transitions in the NIR, keeping the emitter quantum efficiency almost unitary. Finally, by computing the angularly resolved elec-tromagnetic field enhancement inside the nanoslot, the nanoantenna directivity has been designed, proving that strong beaming effects can be obtained. Our findings have a direct impact on the development of bright and effi-cient photon sources operating at telecom wavelength that are of primary importance for quantum nanophotonic applications.
Probing buried interfaces in SiOxNy thin films via ultrafast acoustics: The role transducing layer thickness
Authors: Tauchmanová Martina , Mokrý Pavel , Kanclíř Vít , Václavík Jan , Veselá Petra , Žídek Karel
Published: October 2023

Probing buried interfaces in thin films is a crucial task in many fields, including optical coating. Ultrafast acoustics provide a means to characterize the interfaces by using an acoustic wave localized on the nanometer scale. We provide a brief overview of our thorough study of the interface between SiOxNy thin films and Si substrate by using both single-color and broadband picosecond acoustics. The experiment allows us to track the effect of stoichiometry on the acoustics wave propagation and transition over the layer-substrate interface. To optimize the experiment, we also created simulations to study the effect of optoacoustic layer thickness. We show that the used Ti layer features an optimum thickness between 5-10 nm to reveal details of the interface properties.
Efficient low-power photon upconversion in core/shell heterostructured semiconductor nanowires
Authors: Jansson Mattias , Ishikawa Fumitaro , Chen Weimin M. , Buyanova Irina A.
Published: October 2023

Photon energy upconversion, i.e. the conversion of several low-energy photons to a photon of higher energy, offers significant potential for nano-optoelectronics and nanophotonics applications. The primary challenge is to achieve high upconversion efficiency and a broad device performance range, enabling effective upconversion even at low excitation power. This study demonstrates that core/shell semiconductor nanowire heterostructures can exhibit upconversion efficiencies exceeding what was previously reported for semiconductor nanostructures even at a low excitation power of 100 mW/cm2, by a two-photon absorption process through conduction band states of the narrow-bandgap nanowire shell region. By engineering the electric-field distribution of the excitation light inside the NWs, upconversion efficiency can be further improved by eight times. This work showcases the effectiveness of the proposed approach in achieving efficient photon upconversion using core/shell NW heterostructures, resulting in some of the highest upconversion efficiencies reported in semiconductor nanostructures. Additionally, it offers design guidelines for enhancing energy upconversion efficiency.
Franck Condon analysis of emission and excitation spectra of fused silica materials
Authors: Guesmi Mariem , Thor Tomas , Taboubi Oumayma , Šeděnková Ivana , Panthi Yadu Ram , Pfleger Jiri , Zidek Karel
Published: October 2023

Analysis of defects in optical materials is essential for their applicability in cutting-edge optical components. Since fused silica (FS) counts among the most used materials, deep knowledge about the defects in FS is of high importance. These defects have been routinely identified by studying photoluminescence (PL) emission and its analysis via multiple Gaussian bands. Here we present an extended approach based on the Franck-Condon model to study the defects in FS and the connected pathways of charge carrier relaxation. First, we performed the optical characterization of the FS, including optical absorption, photoluminescence (PL) emission and excitation (PLE), and Fourier-transform infrared (FTIR) and Raman spectroscopy (RS). Based on the analysis of the PLE spectra and vibrational frequencies via RS and FTIR, we created a multi-transition Franck-Condon model, which is able to fully reproduce the PL and PLE spectra. Based on the experimental data and the Franck-Condon fit, we discuss two types of oxygen-deficient centres (ODC) present in this fused silica material and their emission pathways.
Laser assisted processing of nanocrystalline (Ho0.05Y0.95) 2Ti2O7 films for infrared photonics
Authors: Mrázek Jan , Podrazký Ondřej , Proboštová Jana , Vařák Petr , Bartoň Ivo , Baravets Yauhen
Published: October 2023

The existence of new highly thermally and chemically stable active optical materials is a challenging task for current photonics research targeted on high-power lasers. Holmium-doped titanates crystallizing in the pyrochlore lattice, represent a promising class of materials. However, their high processing temperature limits their applications in integrated optical devices. This weakness can be overcome by laser assisted processing as an alternative to common heat-treatment. The amorphous thin films were prepared by a sol-gel method followed by a dip-coating process and densified in a rapid thermal annealing furnace. The densified films were annealed by a CO2 laser beam. The laser irradiation induced a crystallization process resulting in the formation of nanocrystalline (Ho0.05Y0.95)Ti2O7. The prepared film of a thickness 576 nm exhibited an optical transmission of 91.66% close to the maximum theoretical limit of a silica substrate. The film’s refractive index at 632 nm was 2.219. The formation of the nanocrystals caused the activation of the electronic transition 5I7→5I8 at 2 μm and the emission bands showed the distinct Starks splitting which is characteristic for (Ho0.05Y0.95)Ti2O7 phosphors. The presented approach can be used to prepare transparent luminescence films with tailored optical properties by CO2 laser treatment and together with direct laser writing can be used to prepared integrated optical waveguides as an alternative method to common heat-treatment processes.
Liquid Phase Epitaxy growth and luminescence of Terbium-doped Gd3Ga5O12 crystalline layers
Authors: Baillard Amandine , Douissard Paul-Antoine , Loiko Pavel , Wollesen Laura , Martin Thierry , Mathieu Eric , Ziegler Eric , Brasse Gurvan , Camy Patrice
Published: October 2023

Tb3+-doped single-crystalline Gd3Ga5O12 layers are grown by Liquid Phase Epitaxy on (111)-oriented undoped substrates, and their structure, composition, morphology and photo- and radioluminescence are studied. Layers doped with 6 at.% Tb3+ with a thickness up to 20 μm appear promising for single crystal film scintillators with a sub-μm spatial resolution and waveguide lasers as they exhibit good quality, uniform distribution of Tb3+ ions, optimized light output (~50% of that for Ce:YAG), weak concentration quenching of luminescence and low afterglow for a 15 bit dynamic range.
Er-doped zinc-silicate glass-ceramics with enhanced emission in the near-infrared region
Authors: Vařák Petr , Nevindová Pavla , Baborák Jan
Published: October 2023

Erbium-doped lasers and amplifiers exhibit emission around 1.5 μm, which makes them perspective in various applications, such as telecommunications, material processing or defence. The conventionally used silica glass suffers from various drawbacks, such as low solubility of erbium ions or high phonon energy of the silica lattice, which limit the luminescence properties. The zinc-silicate glass-ceramics containing ZnO or Zn2SiO4 nanocrystals represent a suitable alternative. The incorporation of erbium ions into the nanocrystals should result in the enhancement of luminescence properties. In this work, we prepared a zinc-silicate glass-ceramic material containing Zn2SiO4 nanocrystals by the controlled heat treatment of a precursor glass. The luminescence properties of the 1.5 μm emission were measured and the influence of the crystallization on the near-infrared emission was evaluated.
Polarized spectroscopy of Sm3+ ions in monoclinic KGd(WO4)2 crystals
Authors: Baillard Amandine , Loiko Pavel , Rytz Daniel , Schwung Sebastian , Pavlyuk Anatoly , Kornienko Aleksei , Dunina Elena , Fomicheva Liudmila , Fromager Michaël , Braud Alain , Camy Patrice
Published: October 2023

We report on a polarization-resolved spectroscopic study of Sm3+-doped monoclinic KGd(WO4)2 crystals. The transition probabilities for Sm3+ ions were calculated using a modified Judd-Ofelt theory. For the 4G5/2 → 6H9/2 transition in the red spectral range, the stimulated-emission cross-section is 5.59×10-21 cm² at 649.0 nm (for light polarization E || Np) and the luminescence lifetime of the 4G5/2 state is 719 μs (0.4 at.% Sm3+-doping). Sm:KGd(WO4)2 is promising for orange and red lasers.
µJ-level normal dispersion fiber optical parametric chirped-pulse oscillator based on a collapsed-ends photonic crystal fiber
Authors: Guezennec Tristan , Idlahcen Said , Cervera Armand , Hanzard Pierre-Henry , Landais David , Provino Laurent , Haboucha Adil , Godin Thomas , Hideur Ammar
Published: October 2023

We demonstrate the generation of broadband tunable and synchronized pulses exceeding the microjoule level using the new concept of fiber optical parametric chirped-pulse oscillation (FOPCPO). The oscillator is based on a collapsed-ends photonic crystal fiber pumped in the normal dispersion regime by a fiber laser.
An overview of dissipative soliton resonance in fiber lasers
Authors: Bessin Florent , Komarov Andrey , Semaan Georges , Sanchez François
Published: October 2023

Because of the pulse energy quantization in fiber lasers, it is of great importance to find effective ways to increase the pulse energy directly from a fiber laser. An efficient technique is based on the dissipative soliton resonance (DSR) effect. The DSR manifest as a square pulse with constant peak power and a linear increase of both the pulse energy and duration for increasing pumping power. In practice, DSR is favoured with the use of long cavities. In this communication we propose an overview of DSR in fiber lasers including general theoretical approaches together with the most recent relevant experimental results.
AlGaAs Bragg reflection waveguides for hybrid quantum photonic devices
Authors: Lazzari Lorenzo , Schuhmann Jérémie , Lemaître Aristide , Amanti Maria I. , Boeuf Frédéric , Raineri Fabrice , Baboux Florent , Ducci Sara
Published: October 2023

Hybrid photonic devices represent a promising solution to the effective on-chip integration of all the components required for the generation, manipulation and detection of non-classical states of light encoding quantum information. We present an AlGaAs source of highly entangled photon pairs envisioned for the hybridization with silicon-on-insulator integrated platforms, in order to take benefit from the strong second order nonlinearity and the compliance with electrical pumping of the III-V platform and the maturity and CMOS compatibility of silicon photonic circuitry, enabling a wide variety of quantum information applications.
Intermodal-vectorial four-wave mixing processes involving LP01, LP11, LP02 and LP21 modes of birefringent fibers
Authors: Tarnowski Karol , Żołnacz Kinga , Majchrowska Sylwia , Urbańczyk Wacław
Published: October 2023

We present the complete (analytical, numerical and experimental) analysis of intermodal-vectorial four-wave mixings proccesses in birefringent fibers. We analyze phase-matching condition and overlap coeffi-cients to indicate possible processes. Then, we demonstrate multiple four-wave mixing processes in LP01 and LP11 modes numerically and experimentally. Finally, we extend theoretical analysis to account higher-order modes: LP02 and LP21.
Broadband THz quantum cascade laser frequency combs with surface emission and inverse-designed facet reflectors
Authors: Senica Urban , Gloor Sebastian , Micheletti Paolo , Beck Mattias , Faist Jérôme , Scalari Giacomo
Published: October 2023

We present a planarized waveguide cavity with an integrated broadband output coupler that improves both the output power and far-field properties of THz quantum cascade laser frequency combs. The laser mirror reflectivity can be tuned by the shape of the end facet, which is obtained with an efficient inverse design algorithm, where the structure is iteratively updated to match the desired figure of merit. Surface emission is achieved with a broadband patch-array antenna, and all the components have been optimized for octave-spanning emission spectra (2-4 THz). Experimentally, we demonstrate a broadband surface-emitting THz quantum cascade laser frequency comb with optical bandwidths of up to 800 GHz, surface emission into a narrow beam with divergence below (20° x 20°) and a peak power of 13 mW.
Mid-IR frequency laser control with a comb for H2+ spectroscopy
Authors: Mbardi Abdessamad , Leuliet Maxime , Argence Bérengère , Karr Jean-Philippe , Hilico Laurent
Published: October 2023

We will report our recent progress toward H2+ spectroscopy by use of a SI-referenced Mid-IR source laser. H2+ molecular ions are very interesting candidates to improve the determination of fundamental constants, such as the proton to electron mass ratio mp/me and search for new physics beyond the standard model. At LKB, an erbium fibered frequency comb is phase locked to the LNE-SYRTE frequency standards thanks to the T-REFIMEVE network. By sum frequency generation in a AgGaSe2 crystal between a CO2 laser and an output of the comb at 1895 nm, a shifted frequency comb centered at 1560 nm is generated. The latter is then mixed with the original one to generate a beatnote used to stabilise the Mid-IR laser. As a first application, a narrow saturated absorption line in formic acid has been extensively studied. Pressure, power and modulation depth shifts and broadenings have been evaluated, leading to a determination of its central frequency at a sub ppt (10-12) resolution, high enough for H2+ spectroscopy and fundamental constant determination.
Experimental demonstration of a low repetition rate optical frequency comb
Authors: Canella Francesco , Weitenberg Johannes , Dwivedi Paras , Schmid Fabian , Galzerano Gianluca , Hänsch Theodor W. , Udem Thomas , Ozawa Akira
Published: October 2023

Optical frequency combs operating at low repetition rate exhibit high pulse energy for a given average power. Therefore, low repetition rate frequency combs may efficiently drive nonlinear frequency conversion into the mid-infrared or extreme ultraviolet region to extend frequency metrology to such exotic wavelengths. In this work, we have experimentally demonstrated a low-noise optical frequency comb operating at 40 kHz repetition rate using a Yb:KYW mode-locked laser (center wavelength at 1030 nm, repetition rate 40 MHz) and an acousto-optic modulator-based pulse picker. We have stabilized a single comb mode to an ultra-stable continuous wave laser operating at 1033 nm. The integral rms phase noise (in the range 10 Hz - 20 kHz) was measured to be 167.2 mrad.
Non-linear amplification to 200 W of an electro-optic frequency comb with GHz tunable repetition rates
Authors: Ye Hanyu , Leroy Florian , Pontagnier Lilia , Santarelli Giorgio , Boullet Johan , Cormier Eric
Published: October 2023

We present a monolithic Yb-doped fiber laser system delivering 200 W average power of femtosecond pulses at tunable GHz repetition rates. The system is based on a GHz electro-optic (EO) frequency comb operating in the nonlinear regime. The EO comb pulses at 1 µm wavelength are initially pre-compressed to sub-2 ps, amplified to 2.5 W, and finally boosted to 200 W in a newly designed large-mode-area, Yb-doped photonic crystal fiber. Continuously tunable across 1-18 GHz, the picosecond pulses experience nonlinear propagation in the booster amplifier, leading to output pulses compressible down to several hundreds of femtoseconds. To push our system deeper into the nonlinear amplification regime, the pulse repetition rate is further reduced to 2 GHz, enabling significant spectral broadening at 200 W. Characterization reveals sub-200 fs duration after compression. The present EO-comb seeded nonlinear amplification system opens a new route to the development of high-power, tunable GHz-repetition-rate, femtosecond fiber lasers.
Comb-based FTIR spectroscopy of CO perturbed by N2 at 4.6 µm
Authors: Nishiyama Akiko , Kowzan Grzegorz , Charczun Dominik , Ciuryło Roman , Masłowski Piotr
Published: October 2023

Line-shape measurements of the fundamental vibrational band of CO at 4.6 µm perturbed by N2 with a mid-infrared frequency comb-based Fourier-transform spectrometer were performed. Precise collisional line-shape parameters for 41 lines were determined, including the pressure broadening and shifting and speed-dependence of the collisional width. The results were compared with sparse literature data available.
Generation of phase-stable sub-mJ ultrashort laser pulse bursts with extremely high scalable pulse number
Authors: Stummer Vinzenz , Flöry Tobias , Schneller Matthias , Kaksis Edgar , Zeiler Markus , Pugzlys Audrius , Baltuska Andrius
Published: October 2023

We demonstrate generation of bursts that consist of up to 40 ultrashort pulses with 10 μJ pulse energy, 250 fs pulse duration and an ultrashort tunable spacing, from picoseconds to nanoseconds, corresponding to a terahertz intraburst repetition rate. This was achieved by the build-up of a novel thermally-stable sub-mJ Vernier Regenerative Amplifier (RA), whose round-trip detuning is similar to its master oscillator round-trip time. The RA includes two cavities pumped from a common diode, and is able to provide for either 2 bursts (one burst out of each cavity), or for one burst and a synchronous reference pulse for characterization.
Experimental demonstration of an optimized method to generate multi-pulse structures in mode-locked fibre laser
Authors: Malfondet Alix , Grelu Philippe , Millot Guy , Tchofo-Dinda Patrice
Published: October 2023

We present here an experimental demonstration of a new method to access the multi-pulse regime in mode-locked fibre laser. This method allows us to drastically reduce the pumping power, while having a stable train of multiple pulses.
Machine learning-assisted extreme events forecasting in Kerr ring resonators
Authors: Coulibaly Saliya , Bessin Florent , Clerc Marcel , Mussot Arnaud
Published: October 2023

Predicting complex nonlinear dynamical systems has been even more urgent because of the emergence of extreme events such as earthquakes, volcanic eruptions, extreme weather events (lightning, hurricanes/cyclones, blizzards, tornadoes), and giant oceanic rogue waves, to mention a few. The recent milestones in the machine learning framework o↵er a new prospect in this area. For a high dimensional chaotic system, increasing the system’s size causes an augmentation of the complexity and, finally, the size of the artificial neural network. Here, we propose a new supervised machine learning strategy to locally forecast bursts occurring in the turbulent regime of a fiber ring cavity.
Microstructured molecular BIO-gratings by means of UV induced denaturation - INVITED
Authors: Juste-Dolz Augusto , Delgado-Pinar Martina , Avella-Oliver Miquel , Fernández Estrella , Cruz Jose Luis , Andrés Miguel V. , Maquieira Ángel
Published: October 2023

Rapid, reliable and low cost techniques to fabricate biosensors is a hot topic nowadays. Here, we present a BIO-grating fabricated by means of local, selective denaturing of molecules using UV radiation. A phase-mask is used to generate an interferometric pattern of 1420 nm pitch that, when illuminating a biolayer of BSA molecules lead to its periodic deactivation. After the biorecognition of the specific antibody, aBSA, a BIO-grating is generated due to the height difference between the protein, and the complex protein + antibody. We present the optimization of the fabrication of the BIO-gratings and their AFM characterization. Also, the biosensor performance in terms of limit of detection and limit of quantification will be presented.
Time-of-Flight 3D Single Fibre Endoscopy
Authors: Mekhail Simon Peter , Stellinga Daan , Phillips David , Selyem Adam , Turtaev Sergey , Čižmár Tomáš , Padgett Miles
Published: October 2023

We measure the modal dispersion occurring in a single multimode fibre and account for this using a digital micromirror device to form a raster scanning spot in the far field of the distal facet of the fibre. We perform this with a q-switched 700 ps pulsed laser at a 532 nm wavelength. The raster scanning allows us to spatially interrogate the reflectivity of a scene while the time of flight of the pulse gives distance information allowing for the generation of a three-dimensional image.
Selective Emitter for Solar Thermophotovoltaic Applications
Authors: Caldarelli Antonio , Lee Changkyun , De Luca Daniela , Musto Marilena , Russo Roberto , Bermel Peter
Published: October 2023

Selective Emitters (SEs) are the main components of solar thermophotovoltaic (STPV) systems; they act as intermediate thermal radiation emitters to shape the incident solar spectrum to match the wavelengths useful for the PV cell. In this work, we present the design, optimisation, fabrication, and characterisation of an SE based on a multilayer design made of SiNx, SiO2, and TiO2 layers. The SE is optimised to work with PV cells based on III-V semiconductors, such as GaSb, InGaAs, and InGaAsS, the bests suitable for SPTV applications. The fabricated SE shows an emitter efficiency (ηSE) of 50% if matched with a PV cell with an energy bandgap of 0.63 eV.
Refractive index measurements of ethanol-water binary liquid solutions using a graded-index fiber tip sensor
Authors: Soares Liliana , Cunha Cristina , Novais Susana , Ferreira António , Frazão Orlando , Silva and Susana
Published: October 2023

The refractometric analysis of ethanol-water mixtures is hampered because this type of binary solution does not present a linear behaviour. In this work it is proposed a multimode Graded-Index Fiber (GIF) tip sensor for the measurement of ethanol in binary liquid solutions of ethanol-water. The probe is fabricated by fusion-splicing a 500 µm GIF to a Single Mode Fiber (SMF) and it operates as a refractometric sensor in reflection. Samples of ethanol-water mixtures were measured at different temperatures (20°C to 60°C) to evaluate the probe’s capability to detect variations in ethanol refractive index. The samples have different % (v/v) of ethanol, in a range between 0% and 100%.
Computation and implementation of large scalable Spiking Neural Network
Authors: Talukder Ria , Skalli Anas , Porte Xavier , Brunner Daniel
Published: October 2023

Photonic neural networks are a highly sought-after area of research due to their potential for high-performance complex computing. Unlike artificial neural networks, which use simple nonlinear maps, biological neurons transmit information and perform computations through spikes that depend on spike time and/or rate. Through comprehensive studies and experiments, a strong foundation has been laid for the development of photonic neural networks. We have recently developed a large-scale spiking neural network, which serves as a proof-of-concept experiment for novel bio-inspired learning concepts. This breakthrough is significant because it demonstrates the potential of using photonic neural networks for advanced computing and highlights the importance of incorporating biological principles into artificial intelligence research.
Machine learning powered framework for detection of micro- and nanoplastics using optical photothermal infrared spectroscopy
Authors: Xie Junhao , Yang Cihang , Gowen Aoife , Xu Junli
Published: October 2023

Despite the breadth of scientific literature on micro- and nanoplastics (MNPs), a standardized procedure for detecting MNPs is still lacking so far, leading to incomparable results between published studies. This work innovatively proposed the combination of machine learning with advanced optical photothermal infrared (O-PTIR) spectroscopy to develop an efficient and reliable detection framework for MNPs. Spectra of MPs and non-MPs were first collected and inputted to build a classification model, based on which four important wavenumbers were selected. A simplified support vector machine (SVM) model was subsequently developed using the selected four wavenumbers. Good predictive ability was evidenced by a high accuracy of 0.9133. The developed method can improve speed as well as the reliability of results, having a great potential for routine analysis of MNPs, ultimately leading to the standardization of detection methods.
On bi-infinite and conjugate post correspondence problems
Authors: Finkel Olivier , Halava Vesa , Harju Tero , Sahla Esa
Published: October 2023

We study two modifications of the Post Correspondence Problem (PCP), namely (1) the bi-infinite version, where it is asked whether there exists a bi-infinite word such that two given morphisms agree on it, and (2) the conjugate version, where we require the images of a solution for two given morphisms are conjugates of each other. For the conjugate PCP we give an undecidability proof by reducing it to the word problem for a special type of semi-Thue systems and for the bi-infinite PCP we give a simple argument that it is in the class Σ20 of the arithmetical hierarchy.
Intracranial Pressure Monitoring in Patients with Severe Traumatic Brain Injury: A Cohort Study with Paired Analysis
Authors: Torres Gabriel Saboia de Araújo , Paiva Wellingson Silva , Amorim Robson Luís Oliveira de
Published: October 2023

Introduction Intracranial hypertension continues to be the most frequent cause of death in patients with traumatic brain injury (TBI). Thus, invasive monitoring of intracranial pressure (ICP) is a very important tool in neurointensivism. However, there is controversy regarding ICP monitoring and prognosis.

Objectives To evaluate whether there is a difference in mortality between patients with severe TBI who underwent invasive ICP monitoring compared with those who did not undergo such procedure.

Methodology This is a unicentric study in the prospective cohort mode. A total of 316 patients with severe TBI were evaluated and, out of these 316 individuals, 35 were submitted to ICP monitoring. All clinical data were evaluated by the Tertiary Hospital Neurosurgery team in the city of São Paulo.

Results Of the total cohort, 35 (11%) patients underwent ICP monitoring, while 281 did not. Comparing the 2 groups, there was no difference in terms of early mortality between patients who were submitted to monitoring and those who were not (34.3 versus 14.3%; p = 0.09); there was also no difference in terms of hospital mortality (40 versus 28.5%; p = 0.31) or intensive care unit (ICU) length of stay (16.10 days, 95% confidence interval [CI]: 10.6–21.6; versus 20.60 days, 95%CI: 13.50–27.70; p = 0.31).

Conclusions In this cohort, we did not identify differences in mortality or in duration of hospitalization between patients with ICP monitoring and those exclusively with clinical-radiological evaluation. However, further national co-operative studies of services using ICP monitoring are needed to achieve results with greater generalization power.
Synthesis of Highly Substituted 1,2,4-Triazole-Based 3-Nitrochromanes through Aza-Michael Addition Reaction under Catalyst- and Base-Free Conditions
Authors: Mohapatra Seetaram , Das Tapaswini , Parida Sonali Priyadarshini , Nayak Sabita
Published: October 2023

A simple and efficient aza-Michael addition reaction of 1,2,4-triazoles to functionalized 2-aryl-3-nitro-2H-chromenes has been demonstrated under catalyst- and base-free conditions. In this transformation, one intermolecular C–N bond formation is achieved at room temperature. A series of highly substituted 1,2,4-triazole-based 3-nitrochromanes were produced in good to excellent yields, up to 86%. The relative configuration of the Michael adducts was confirmed by X-ray crystallographic analysis. High yield, easy accessibility and a wide variety of functional group tolerance are the key features of this aza-Michael­ addition reaction.
Pituitary Metastasis of Clear Cell Renal Carcinoma Mimicking Pituitary Macroadenoma – Case Report
Authors: Nogueira Lucas Caixeta , Silva Luciano Ricardo França da , Tenório Luiz Eduardo Mendonça , Menezes Cleiton Onofre de , Calado João Victor Franco de Oliveira , Rosa Luiz Felipe Gomes , Moussalem Guilherme Figner , Leventi Nicolai Máximo
Published: October 2023

Introduction Pituitary tumors account for 25% of all primary brain tumors and for 15% of overall intracranial expansive masses. Pituitary metastases, in contrast, are a rare condition, estimated as 1.8% of all resected sellar lesions. We present here a rare case of clear cell renal carcinoma metastasis to the pituitary gland.

Case Report A 65-year-old patient with holocranial headache and diplopia, whose physical examination showed right eye abduction palsy and ipsilateral anisocoria. Magnetic resonance imaging (MRI) of the pituitary revealed a heterogeneous mass in T1 weighted imaging with mild peripheral contrast enhancement and considerable growth during follow-up. Prolactin levels were high and dropped to normal after use of cabergoline, but remained normal even after the medication was halted. Biopsy was compatible with clear cell renal carcinoma. After surgery, the patient underwent radiotherapy, which was effective in reducing the volume of the lesion.

Discussion Only 25 cases of pituitary metastasis arising from the kidney were reported in the literature between the years of 1957 and 2018. Metastases can reach the pituitary through hematogenous spread, cerebrospinal fluid, and contiguous bony lesions. Clinical presentation varies from vague complaints such as fatigue or headache to more specific signs like polyuria and polydipsia, and ∼ 60% of cases have clinical manifestations.

Conclusion Case reports of pituitary metastases are low worldwide, with only 25 case reports of kidney metastases in over a 60-year period. The rarity of the lesions and hormonal alterations due to pituitary stalk compression can mislead diagnosis, and some patients may even never be diagnosed regarding their lower life span. In this report, radiotherapy was effective postresection, and accounts for a treatment option. All these issues account for the relevance of these case reports.
Long-term Changes of Infrared Thermography in Successful Decompression of Carpal Tunnel Syndrome: A Case Report
Authors: Ferreira Matheus Henrique Oliveira , Borges Pedro Neves , Fontinha Paulo Roberto Bastos , Acioly Marcus André
Published: October 2023

Introduction Infrared thermography (IRT) has demonstrated high diagnostic accuracy for carpal tunnel syndrome (CTS) diagnosis in previous studies. However, the recovery of the autonomic function after treatment for CTS is rarely addressed in the literature, especially on the long-term.

Case Presentation A 59-year-old lady sought treatment for a long-term history of numbness, tingling, and hand and arm pain. CTS was diagnosed by clinical and electrophysiological means. After 6 months of conservative treatment, surgical treatment was offered. Preoperative IRT was performed by static and dynamic evaluations immediately and 5 minutes after the cold challenge test using the FLIR C2 camera with accuracy of 2°C or 2%. Fingers were consistently colder (mean of 3.76°C), which clearly represented an autonomic dysfunction in the patient's hand. The patient underwent mini-open carpal tunnel decompression and did great postoperatively. One year after surgery, the patient was fully recovered and completely asymptomatic. IRT imaging showed a remarkable improvement of fingers temperature (mean of 3.36°C).

Conclusion Our long-term results confirmed that functional recovery occurred concomitantly to autonomic recovery, which was demonstrated by consistent improvement in fingers' temperature. IRT has a strong potential at the evaluation of patients with CTS for both diagnosis and follow-up.
Postoperative Opioid Consumption is Greater after Simultaneous versus Staged Bilateral Total Knee Arthroplasty
Authors: Sustich Sara J. , Stambough Jeffrey B. , Hui Ryan , Siegel Eric R. , Barnes C. Lowry , Mears Simon C.
Published: October 2023

Increased exposure to opioids around total knee arthroplasty (TKA) can lead to a risk of long-term dependence. We hypothesized that performing simultaneous bilateral total knee arthroplasty (simBTKA) over staged surgery (staged bilateral total knee arthroplasty [stgBTKA]) may decrease the total amount of opiates used. We retrospectively reviewed 29 patients who underwent simBTKAs performed between February 2015 and November 2020 and identified 23 that did not use opioids ≤90 days prior to surgery. These were frequency matched for gender and body mass index to 50 stgBTKAs completed within 6 months who also were opioid-free ≤90 days prior to their first surgery. Using our state's prescription database, we reviewed postsurgery opioid refills and morphine milligram equivalents (MMEs) for the two groups and compared their initial MME prescription at discharge and their total MME consumption 6 months postoperatively. Total MME consumption for the stgBTKA group included all prescriptions following the first and 6 months after the second surgery, whereas for the simBTKA group, total consumption included the 6 months after their two same-day surgeries. The simBTKA group had more MMEs prescribed initially (median = 375) than did the stgBTKA group after second surgery (median = 300; p < 0.007), larger postoperative-refill MMEs in the first 30 days (median = 300) than stgBTKA (median = 0; p = 0.221) and increased total MME consumption 6 months after surgery (median = 675) compared with stgBTKA after second surgery (median = 450; p = 0.077). However, both groups had similar monthly consumptions rates, with medians I MMEs/month of 112 for simBTKA versus 96 for stgBTKA (p = 0.585). Our results suggest there is no significant difference in opioid consumption between simBTKA and stgBTKA. In fact, we found that simBTKA patients received larger opioid amounts in the immediate postoperative period as well as slightly larger amounts at 30 days.
Krankenhauscontrolling: Die Komplexität nimmt zu
Authors: Hohorst Anneke , Gräb David
Published: October 2023

Die mit der Krankenhausreform geplante Einführung von Leistungsgruppen samt Qualitätskriterien sowie Vorhaltebudgets und veränderten Fallpauschalen verspricht eine Revolution. Für das Krankenhauscontrolling wird die Umsetzung eine Herausforderung.
Simultandolmetschen: Strategien gegen die Sprachbarriere
Authors: Lang Michael
Published: October 2023

Die Bundesregierung hat den Handlungsbedarf für eine bessere Sprachmittlung im Gesundheitswesen erkannt. Zertifizierte Dolmetscher sollen die Gespräche zwischen Arzt und Patient in Echtzeit übersetzen. In naher Zukunft sollen auch Algorithmen diese Arbeit übernehmen können.
A Century of Laffer-Ascher Syndrome
Authors: Rewri Parveen , Garg Swapnil , Kumar Rajender , Gupta Gulab
Published: October 2023

Laffer-Ascher syndrome is characterized by double lips, blepharochalasis, and nongoiter thyroid enlargement. The syndrome was first described in 1923 and several case reports have been published thereafter. We illustrate the syndrome through a case of a 46-year-old woman who presented with both upper and lower double lips and blepharochalasis, and review the literature published.

Thyroid involvement is the most inconsistent feature of the syndrome complex described in reported cases.
ASVAL with Phlebectomy/Sclerofoam Technique: Preliminary Results
Authors: Garavello Alberto , Fiamma Paola , Oliva Enrico
Published: October 2023

The ambulatory selective varicose vein ablation under local anesthesia (ASVAL) method recommends preserving the great saphenous vein (GSV), unless there is a serious terminal valve insufficiency, and suggests phlebectomy of superficial varicose reservoir as a primary treatment. To increase patient comfort, foam safety and cosmetic results, we used ASVAL with a mixed phlebectomy/foam technique on local anesthesia. Thirty consecutive patients treated with ASVAL phlebectomy-sclerofoam technique were reviewed retrospectively between December 2022 and April 2023. All patients were evaluated by clinical examination and duplex ultrasound (DUS); the main selection criteria were a minimal GSV insufficiency (main GSV < or = to 1 cm). Muller phlebectomy of tributaries at entry point in the saphenous trunk was performed; after 1 week, patients were checked for foam sclerotherapy of residual trunk. Under visual control, 0.5% polidocanol foam (from 5 to 10 cc. “Tessari Technique”) was injected in visible veins and elastic compression with pad was applied for 1 week. Compression with Class I elastic stockings was prescribed, and patients were reviewed after 1 month. Postoperative complications included thigh hematoma in two patients, three thrombosis of injected trunk, and hyperpigmentation in three patients. No GSV thrombosis at DUS was recorded. In 27 patients, a satisfying cosmetic result was achieved, and in 3 patients a new foam session was needed. Phlebectomy/foam ASVAL technique is a safe, low-traumatic technique with no need of US guidance, with less risk of foam migrating in GSV, simple and inexpensive, for patients with less advanced GSV insufficiency.
Good soldiers or bad apples? Exploring the impact of employee narcissism on constructive and destructive voice
Authors: Cui Zilong
Published: October 2023

Narcissists have always been thought to have both positive and negative characteristics. However, the existing research regarding the ways that narcissistic employees express such positive and negative traits in organizations is still limited. The results of a longitudinal field study based on 450 participants of one Chinese firm to investigate the hypothesized model. The results show that employee narcissism has a positive effect on destructive voice via perceived overqualification. Moreover, organizational identification weakens the relation between employee narcissism and destructive voice via perceived overqualification. The results casts light on the mechanism between employee narcissism and voice. These findings provide significant insights for organizations in regard to the managing of narcissistic employees and overqualified employees. These findings also have important practical implications for organizations, enabling them to develop more appropriate human resource management strategies for narcissistic employees.
Tutorial: Nonlinear magnonics
Authors: Zheng Shasha , Wang Zhenyu , Wang Yipu , Sun Fengxiao , He Qiongyi , Yan Peng , Yuan H. Y.
Published: October 2023

Nonlinear magnonics studies the nonlinear interaction between magnons and other physical platforms (phonon, photon, qubit, spin texture) to generate novel magnon states for information processing. In this Tutorial, we first introduce the nonlinear interactions of magnons in pure magnetic systems and hybrid magnon–phonon and magnon–photon systems. Then, we show how these nonlinear interactions can generate exotic magnonic phenomena. In the classical regime, we will cover the parametric excitation of magnons, bistability and multistability, and magnonic frequency comb. In the quantum regime, we will discuss the single-magnon state, Schrödinger cat state, and the entanglement and quantum steering among magnons, photons, and phonons. The applications of the hybrid magnonics systems in quantum transducer and sensing will also be presented. Finally, we look at the future development direction of nonlinear magnonics.
High-density and high-uniformity InAs quantum nanowires on Si(111) substrates
Authors: Nakagawa Ryusuke , Watanabe Rikuta , Miyashita Naoya , Yamaguchi Koichi
Published: October 2023

InAs nanowires (NWs) were grown on SiOx pinholes formed on Si(111) substrates by molecular beam epitaxy. Influences of electron-beam (EB) irradiation on the SiOx layer on the pinhole formation and the subsequent InAs NW growth were studied. As the EB irradiation dose increased, the pinhole density in the SiOx layer decreased. From atomic force microscopy, transmission electron microscopy, and x-ray photoelectron spectroscopy results, it was found that the pinhole etching of the SiOx layer by Ga droplets was suppressed by carbon adsorption due to the EB irradiation. By forming high-density pinholes on the SiOx layer without the EB irradiation, high-density InAs NWs with 1–2 × 1010 cm−2 were grown successfully, and the uniformity in the NW diameter improved. The standard deviation of the NW diameter was 1.8 nm (8.8%) for high-density NWs. In addition, the NW diameter decreased with decreasing EB dose, and the NW diameter was controlled by adjusting the diameter of Ga droplets forming the pinholes. As the NW diameter decreased, photoluminescence spectra of the NWs shifted to higher energies than the bandgap energy of the wurtzite InAs bulk. From these results, we successfully fabricated high-density and high-uniformity InAs NWs with quantum size effects on EB-unirradiated SiOx/Si(111).
Theoretical calculation on adsorption of molecular hydrogen in monolayer ZnO
Authors: Ghosh Sulagna , Nath Palash , Moshat Sudipta , Sanyal Dirtha
Published: October 2023

Adsorption, desorption, and diffusion dynamics of hydrogen gas molecules over a hexagonal ZnO monolayer have been studied thoroughly in the van der Waals Density Functional Theory (vdW-DFT) framework in association with kinetic Monte Carlo (kMC) simulations. Hydrogen molecules can attach to a ZnO sheet via a weak physisorption process with a limitation of maximum attachment of three molecules per hexagonal ring. Pressure and temperature are the main deciding parameters for the overall storage capacity of hydrogen on a ZnO substrate. kMC simulations are performed to capture the stochastic behavior of surface dynamics of gas molecules. Adsorption energy and diffusion barrier are predicted to be around 50–60 meV and 4–12 meV, respectively, according to vdW-DFT calculations. kMC simulations with these energy parameters estimate the surface coverage of hydrogen to be pretty high below room temperature and high pressure. Furthermore, the hydrogen adsorption in the ZnO monolayer leads to the increase of the bandgap value, subsequently changing the conductivity of the material. The present research work sheds light on the usage of a ZnO monolayer for suitable hydrogen gas storage and sensing applications.
High-accuracy calculation of singular electromagnetic fields in regions with re-entrant peripheries
Authors: Pham Dung N. , Bharadwaj Sathwik , Rodriguez Shanshan , Rodriguez Leo , Ram-Mohan L. R.
Published: October 2023

Accurate analysis of the electromagnetic fields inside waveguides and cavities with re-entrant boundaries is crucial for many multi-scale device applications. In earlier approaches, the singularities that exist in electromagnetic field gradients inside such waveguides and cavities significantly reduce the accuracy of the calculations. In our scheme, these singular behaviors are treated using Hermite finite elements combined with analytical regularization of the action integral. We show that this approach provides considerably higher accuracy as compared with other methods employed in the literature. Specific calculations are presented for three typical regions: (a) an L-shaped waveguide, (b) an L-cavity, and (c) a cubic cavity with an octant removed to form a triple-junction corner. The method can be adapted to evaluate very high electromagnetic fields in any complex structures displaying “hot points.”
Experimental validation of multiferroic antennas in GHz frequency range
Authors: Xu Rui-Fu , Ippet-Letembet Louis-Charles , Tiwari Sidhant , Yao Zhi (Jackie) , Huang Shih-Ming , Candler Rob N. , Chen Shih-Yuan
Published: October 2023

Various mechanical antennas have emerged to overcome the inherently narrower bandwidth and degraded efficiency in electrically small antennas. Among them, multiferroic antennas are expected to realize high-frequency applications and maintain their performance, even with significantly reduced sizes. However, experimental proof of such radiation from multiferroic or magnetoelectric coupling in the GHz range deserves further examination. This paper designs and fabricates a series of multiferroic antenna samples with mechanical resonances at around 3.5 and 6 GHz, and their radiation transmissions are tested at these resonances. Nickel, a magnetoelastic material, consistently exhibits magnetically induced radiation at both resonances. However, magnetic material consisting of Permalloy (Ni78Fe22), known for its much weaker magnetoelastic effects, still shows similar transmission behaviors at 3.67 GHz and enhanced power absorption at 6.42 GHz. Our results indicate that the dynamic response of magnetoelastic materials in the GHz band should differ from their response at the MHz and below bands. This evidence calls for further investigations of the source of magnetoelectric radiation.
Leading-edge vortex and aerodynamic performance scaling in a simplified vertical-axis wind turbine
Authors: Ahnn Sangwoo , Choi Haecheon
Published: October 2023

Numerical analysis is conducted to investigate the aerodynamic performance and characteristics of flow around a simplified vertical-axis wind turbine (VAWT) by varying the tip-speed ratio and number of blades. The tip-speed ratios considered are λ=RΩ/U0=0.8−2.4, and the numbers of blades are n=2−5 at the Reynolds number of Re=U0D/ν=80 000, where D(=2R) and Ω are the turbine diameter and rotation rate, respectively, U0 is the free-stream velocity, and ν is the kinematic viscosity. The primary flow feature observed around the VAWT is the formation and evolution of leading-edge vortices (LEVs) at lower tip-speed ratios of λ=0.8−1.2, which have a notable impact on the power coefficient in the upwind region. At high tip-speed ratios (λ>1.2), the LEV is not generated due to fast blade rotating speeds. Depending on the tip-speed ratio and solidity (σ=nc/πD, where c represents the blade chord length), these LEVs are generated at different azimuthal angles and exhibit varying strengths. A modified tip-speed ratio, λ′=λ/π(1−σ), proposed in the present study allows the flow structures with different λ's and n's to exhibit similarity when they are represented with λ′. Thus, the time-averaged power coefficient (i.e., aerodynamic performance; C¯PW) is a function of λ′ (rather than λ and n) in the range of σ=0.2−0.5 considered, and its maximum occurs at λ′=0.45−0.5 regardless of the number of blades, providing the optimal tip-speed ratio of λopt=γπ(1−σ), where γ=0.45−0.5. Finally, we show that C¯PW/(σλ3) is a function of λ′.