Noise investigation of CW and mode-locked harmonic cavity nanolasers.

We theoretically investigate the noise properties of harmonic cavity nanolasers by introducing a model of coupled equations of evolution of the modes, taking spontaneous emission into account. This model is used to predict the noise among the nanolaser Hermite-Gaussian modes, both in continuous wave and mode-locked regimes. In the first case, the laser noise is described in terms of noise modes, thus illustrating the role of the laser dynamics. In the latter case, this leads to the calculation of the fluctuations of the pulse train parameters. The influence of the different laser parameters, including the amount of saturated absorption and the Henry factors, on the noise of the mode-locked regime is discussed in details.

Analysis of Pros and Cons in Using [68Ga]Ga-PSMA-11 and [18F]PSMA-1007: Production, Costs, and PET/CT Applications in Patients with Prostate Cancer.

The aim of this work is to compare [68Ga]Ga-PSMA-11 and [18F]PSMA-1007 PET/CT as imaging agents in patients with prostate cancer (PCa). Comparisons were made by evaluating times and costs of the radiolabeling process, imaging features including pharmacokinetics, and impact on patient management. The analysis of advantages and drawbacks of both radioligands might help to make a better choice based on firm data. For [68Ga]Ga-PSMA-11, the radiochemical yield (RCY) using a low starting activity (L, average activity of 596.55 ± 37.97 MBq) was of 80.98 ± 0.05%, while using a high one (H, average activity of 1436.27 ± 68.68 MBq), the RCY was 71.48 ± 0.04%. Thus, increased starting activities of [68Ga]-chloride negatively influenced the RCY. A similar scenario occurred for [18F]PSMA-1007. The rate of detection of PCa lesions by Positron Emission Tomography/Computed Tomography (PET/CT) was similar for both radioligands, while their distribution in normal organs significantly differed. Furthermore, similar patterns of biodistribution were found among [18F]PSMA-1007, [68Ga]Ga-PSMA-11, and [177Lu]Lu-PSMA-617, the most used agent for RLT. Moreover, the analysis of economical aspects for each single batch of production corrected for the number of allowed PET/CT examinations suggested major advantages of [18F]PSMA-1007 compared with [68Ga]Ga-PSMA-11. Data from this study should support the proper choice in the selection of the PSMA PET radioligand to use on the basis of the cases to study.

Resident human dermal γδT-cells operate as stress-sentinels: Lessons from the hair follicle.

Murine γδT-cells have stress-surveillance functions and are implicated in autoimmunity. Yet, whether human γδT-cells are also stress sentinels and directly promote autoimmune responses in the skin is unknown. Using a novel (mini-)organ assay, we tested if human dermis resident γδT-cells can recognize stressed human scalp hair follicles (HFs) to promote an alopecia areata (AA)-like autoimmune response. Accordingly, we show that γδT-cells from healthy human scalp skin are activated (CD69+), up-regulate the expression of NKG2D and IFN-γ, and become cytotoxic when co-cultured with autologous stressed HFs ex vivo. These autologous γδT-cells induce HF immune privilege collapse, dystrophy, and premature catagen, i.e. three hallmarks of the human autoimmune HF disorder, AA. This is mediated by CXCL12, MICA, and in part by IFN-γ and CD1d. In conclusion, human dermal γδT-cells exert physiological stress-sentinel functions in human skin, where their excessive activity can promote autoimmunity towards stressed HFs that overexpress CD1d, CXCL12, and/or MICA.

Robustness of mode-locking in harmonic cavity nanolasers subjected to potential distortions.

We theoretically analyze the robustness to potential distortion of mode-locking in a harmonic cavity nanolaser sustaining oscillation of Hermite-Gaussian modes. Different types of imperfections of the harmonic potential that create the Hermite-Gaussian modes are considered: the non-parabolicity of the potential and the possible random errors in the shape of the potential. The influence of the different laser parameters, including the Henry factors of the gain medium and the saturable absorber, on the robustness of the mode-locked regime is discussed in detail.

Efficient type II second harmonic generation in an indium gallium phosphide on insulator wire waveguide aligned with a crystallographic axis.

We theoretically and experimentally investigate type II second harmonic generation in III-V-on-insulator wire waveguides. We show that the propagation direction plays a crucial role and that longitudinal field components can be leveraged for robust and efficient conversion. We predict that the maximum theoretical conversion is larger than that of type I second harmonic generation for similar waveguide dimensions and reach an experimental conversion efficiency of 12%/W, limited by the propagation loss.

Alopecia areata treated with topical and systemic brevilin A: A case series.

Alopecia areata (AA) is an autoimmune T CD8 cell mediated condition clinically characterized by hair loss from single or few small patches to complete hair loss. The management of AA is challenging and all available therapies does not ensure a long-term remission. To assess the safety and efficacy of both systemic and topical brevilin A, a natural compound, in AA patients not responding to other treatments. After obtaining informed consent, we administered off-label brevilin A to 13 adult patients affected by AA, for a period ranging from 6 to 18 months. Medical records for each patient and the severity of alopecia tool (SALT) score before and after brevilin A administration were recorded. The mean SALT score of our patients was 81.03 (SD 34.9) at baseline and 75.8 (SD 37.4) after brevilin A therapy, meaning no statistically significant improvement was observed (P = .2385 Paired t test). However, three multifocal AA (MAA) patients out of four attained an improvement (75%) suggesting that brevilin A may be represent an alternative therapy in this form of AA. Authors conclude that brevilin A could represent in the future a possible effective treatment in MAA forms but further studies are required.

Cutaneous adverse reactions after COVID-19 vaccines in a cohort of 2740 Italian subjects: An observational study.

An in-depth characterization of the incidence, morphology, and onset of COVID-19-vaccines cutaneous adverse reactions is currently lacking. The existing literature on COVID-19 vaccination-related cutaneous adverse reactions largely focused on messenger RNA vaccines and mainly included type 1 hypersensitivity reactions, such as urticaria and angioedema. Other cutaneous manifestations are still poorly characterized and have been classified as delayed hypersensitivity rash. Our prospective observational study on a sample of 2740 subjects who underwent the COVID-19 vaccination aimed at defining the prevalence of cutaneous adverse reactions and at identifying their timing of onset and their correlation with the administered dose. Vaccine-related cutaneous adverse reactions occurred in 50 subjects. Patients were asked to complete a questionnaire on the type of COVID-19 vaccine received, the time of onset of cutaneous reactions, and the dates of administration. Out of 2740 individuals who received the COVID-19 vaccination, 50 were diagnosed with cutaneous adverse reactions to vaccine, after the first dose in 28 patients, after the second in 20, and after both in two. We reported localized injection site erythema in 12 patients and generalized cutaneous reactions in 38 patients. Our study shows that cutaneous adverse reactions to COVID-19 vaccination are not common and most often occur after the first dose, recurring infrequently after the second dose. These reactions are usually easily manageable and, even in severe generalized cases, oral antihistamines and corticosteroids were sufficient for resolution. Therefore, except for immediate hypersensitivity reactions, cutaneous adverse reactions do not represent a contraindication to the completion of the vaccination cycle.

A new treatment of alopecia induced by palbociclib: Topical cetirizine.

INTRODUCTION: Recently CDK4/6 inhibitors have been introduced for the treatment of hormone positive breast cancer resistant to endocrine therapy. Among their side effects, alopecia is often reported being associated to patients' distress and depressive symptoms. CASE REPORT: We report the case of a 70-year-old woman affected by breast cancer in treatment with Palbociclib, who developed alopecia.Management and Outcome: We prescribed a topical solution with cetirizine. Global photography, trichoscopy and trichogram were assessed. All evaluations demonstrated alopecia improvement. DISCUSSION: Currently, no treatment options for CDK 4/6 inhibitors induced alopecia have been proposed. Herein, we report the use of topical cetirizine.

Alopecia areata treated with dimethyl fumarate: A case series.

Alopecia areata is an autoimmune condition leading to non-scarring hair loss. Clinically, several presentations ranging from single or few small patches to complete hair loss are documented. The management of alopecia areata is challenging and all available treatments do not ensure a long-term remission to assess the safety and efficacy of systemic dimethyl fumarate in alopecia areata patients not responding to other systemic treatments. After obtaining informed consent, we administered off-label dimethyl fumarate to 10 adult patients with alopecia areata, for a period ranging from 4 to 37 weeks. Medical information for each patient and the severity of alopecia tool (SALT) score before and after dimethyl fumarate administration were recorded. During the treatment, 50% of patients (5 patients out of 10) had a slight improvement of hair regrowth; it was mainly as partial hair regrowth (ranging from 8% to 32%) and only one patient (10%) achieved > 50% terminal hair regrowth. Authors conclude that dimethyl fumarate is not advisable as a treatment of alopecia areata, also considering the risk of fumaric acid esters toxicity.

Isoradiotopic response of discoid lupus after radiotherapy: A case report and review of the literature.

Radiotherapy is frequently associated with a great number of collateral effects, which can affect the skin and its appendages. In addition to more common side effects, like radiodermatitis, other cutaneous conditions are less known and often they are underdiagnosed. Among these, isoradiotopic response is one of the rare radiotherapy-associated phenomena. This term refers to the appearance of a secondary dermatosis in a previously irradiated district. The term was used for the first time by Shurman et al. to describe a case of lichen ruber planus arising in the genital area after radiotherapy for squamous cell carcinoma. The pathologic mechanism is not completely clear, but a few hypotheses have been proposed. Alterations in the local lymphatic drainage, in the nervous system and the immune microenvironment have all been called into play (the immunocompromised district theory). We present the case of a male patient that developed discoid lupus on a previously irradiated cutaneous area and review the literature, highlighting the numerous possible manifestations of this phenomenon.

Dermoscopy and confocal microscopy for different chemotherapy-induced alopecia (CIA) phases characterization: Preliminary study.

BACKGROUND: Chemotherapy-induced alopecia (CIA) affects 65% of patients receiving chemotherapy regimens and is often identified with the massive hair loss stage. Reflectance confocal microscopy (RCM) is a noninvasive technique used in alopecia assessment for disease characterization and state of activity. OBJECTIVE: To describe RCM features of CIA in different timing and identify specific phases of alopecia development. METHODS: A total of 16 patients treated with chemotherapy underwent dermoscopy and RCM evaluations four times during the observation: 2 and 4-6 weeks after starting and 3 and 6 months after the end of chemotherapy. Ten examinations for each stage were performed. RESULTS: Four phases of CIA have been identified. Initial hair loss showed specific dots not previously described, named CIA dots. massive hair loss phase was characterized by black dots (10/10 pt), CIA dots (8/10 pt) and hair shaft abnormalities. Three months after the end of chemotherapy, during the partial regrowth phase, 10/10 patients showed thin hair in regrowth and 8/10 presented black and yellow dots. At 6 months, normal hair in regrowth appears in all patients (total regrowth phase). CONCLUSIONS: Chemotherapy-induced alopecia has to be considered as a dynamic process with specific phases characterized by distinctive dermoscopic and confocal features.

Mode Locking of the Hermite-Gaussian Modes of a Nanolaser.

Mode locking is predicted in a nanolaser cavity forming an effective photonic harmonic potential. The cavity is substantially more compact than a Fabry-Perot resonator with a comparable pulsing period, which is here controlled by the potential. In the limit of instantaneous gain and absorption saturation, mode locking corresponds to a stable dissipative soliton, which is very well approximated by the coherent state of a quantum mechanical harmonic oscillator. This property is robust against noninstantaneous material response and nonzero phase-intensity coupling.

The diagnosis of androgenetic alopecia in children: Considerations of pathophysiological plausibility.

Androgenetic alopecia (AGA), one of the most common causes of hair loss in men and women, is an infrequent cause of alopecia in children. In AGA, patients generally start noticing hair thinning after the onset of puberty due to progressive miniaturisation of the hair follicle which leads to vellus transformation of terminal hair. However, the occurrence of prepubertal AGA has rarely been reported in the literature. The pathophysiology of AGA is tightly linked to androgen hormones; prepubertal children do not usually produce significant amounts of adrenal or gonadal androgens. When it does occur, an underlying abnormality should be suspected. Secondary causes of AGA must be excluded when evaluating a patient before the appearance of puberty. Premature puberty, polycystic ovarian syndrome and other causes of hyperandrogenism can present with hair loss in an androgenetic pattern. This article reviews the normal physiology of androgen hormones and their role in the pathophysiology of childhood AGA.

Silicon-Phosphorene Nanocavity-Enhanced Optical Emission at Telecommunications Wavelengths.

Generating and amplifying light in silicon (Si) continues to attract significant attention due to the possibility of integrating optical and electronic components in a single material platform. Unfortunately, silicon is an indirect band gap material and therefore an inefficient emitter of light. With the rise of integrated photonics, the search for silicon-based light sources has evolved from a scientific quest to a major technological bottleneck for scalable, CMOS-compatible, light sources. Recently, emerging two-dimensional materials have opened the prospect of tailoring material properties based on atomic layers. Few-layer phosphorene, which is isolated through exfoliation from black phosphorus (BP), is a great candidate to partner with silicon due to its layer-tunable direct band gap in the near-infrared where silicon is transparent. Here we demonstrate a hybrid silicon optical emitter composed of few-layer phosphorene nanomaterial flakes coupled to silicon photonic crystal resonators. We show single-mode emission in the telecommunications band of 1.55 µm ( Eg = 0.8 eV) under continuous wave optical excitation at room temperature. The solution-processed few-layer BP flakes enable tunable emission across a broad range of wavelengths and the simultaneous creation of multiple devices. Our work highlights the versatility of the Si-BP material platform for creating optically active devices in integrated silicon chips.

Fully embedded photonic crystal cavity with Q=0.6 million fabricated within a full-process CMOS multiproject wafer.

A two dimensional photonic crystal (PhC) resonator, based on a recent design concept, entirely embedded in Silica, is fabricated in a CMOS full-process multiproject wafer, including additional steps such as implantation, metalization, Germanium deposition and planarization. A large loaded Q-factor (5.9 × 105) is achieved without removal of the silica cladding. A statistical analysis over 56 devices leads to an average value for the loaded Q of 4 × 105, in close agreement with calculations. An upper boundary for the fabrication disorder is estimated to 1.2 nm.

Nonlinearities in GaAs cavities with high CW input powers enabled by photo-oxidation quenching through ALD encapsulation.

We demonstrate that conformal encapsulation using atomic layer deposition of GaAs nano-cavity resonator made of photonic crystal cavity prevents photo-induced oxidation. This improvement allows injecting a large quantity of energy in the resonator without any degradation of the material, thus enabling spectral stability of the resonance. We prove second harmonic and third harmonic generation over more than one decade of pump power variation, thanks to this encapsulation, with a total efficiency (ηSHG = 8.3 × 10-5 W-1 and ηTHG = 1.2 × 10-3 W-2 ) and a large net output energy for both operations (PSHGout=0.2nW and PTHGout=8pW).

Tuning out disorder-induced localization in nanophotonic cavity arrays.

Weakly coupled high-Q nanophotonic cavities are building blocks of slow-light waveguides and other nanophotonic devices. Their functionality critically depends on tuning as resonance frequencies should stay within the bandwidth of the device. Unavoidable disorder leads to random frequency shifts which cause localization of the light in single cavities. We present a new method to finely tune individual resonances of light in a system of coupled nanocavities. We use holographic laser-induced heating and address thermal crosstalk between nanocavities using a response matrix approach. As a main result we observe a simultaneous anticrossing of 3 nanophotonic resonances, which were initially split by disorder.

GaInP on oxide nonlinear photonic crystal technology.

Heat dissipation is improved in nonlinear III-V photonic crystal waveguides owing to the hybrid III-V/Silicon integration platform, allowing efficient four-wave mixing in the continuous-wave regime. A conversion efficiency of -17.6 dB is demonstrated with a pump power level below 100 mW in a dispersion-engineered waveguide with a flat group index of 28 over a 10 nm bandwidth.

Acceleration of the nonlinear dynamics in p-doped indium phosphide nanoscale resonators.

We demonstrated a twofold acceleration of the fast time constant characterizing the recovery of a p-doped indium-phosphide photonic crystal all-optical gate. Time-resolved spectral analysis is compared to a three-dimensional drift-diffusion model for the carrier dynamics, demonstrating the transition from the ambipolar to the faster minority carrier dominated diffusion regime. This opens the perspective for faster yet efficient nanophotonic all-optical gates.