Perturbation theory for Kerr nonlinear leaky cavities.

In emerging open photonic resonators that support quasinormal eigenmodes, fundamental physical quantities and methods have to be carefully redefined. Here, we develop a perturbation theory framework for nonlinear material perturbations in leaky optical cavities. The ambiguity in specifying the stored energy due to the exponential growth of the quasinormal mode field profile is lifted by implicitly specifying it via the accompanying resistive loss. The capabilities of the framework are demonstrated by considering a third-order nonlinear ring resonator and verified by comparing against full-wave nonlinear finite element simulations. The developed theory allows for efficiently modeling nonlinear phenomena in contemporary photonic resonators with radiation and resistive loss.

On the calculation of the quality factor in contemporary photonic resonant structures.

The correct numerical calculation of the resonance characteristics and, principally, the quality factor Q of contemporary photonic and plasmonic resonant systems is of utmost importance, since Q defines the bandwidth and affects nonlinear and spontaneous emission processes. Here, we comparatively assess the commonly used methods for calculating Q using spectral simulations with commercially available, general-purpose software. We study the applicability range of these methods through judiciously selected examples covering different material systems and frequency regimes from the far-infrared to the visible. We take care in highlighting the underlying physical and numerical reasons limiting the applicability of each one. Our findings demonstrate that in contemporary systems (plasmonics, 2D materials) Q calculation is not trivial, mainly due to the physical complication of strong material dispersion and light leakage. Our work can act as a reference for the mindful and accurate calculation of the quality factor and can serve as a handbook for its evaluation in guided-wave and free-space photonic and plasmonic resonant systems.

Anal canal squamous cell cancer: are surgical alternatives to chemoradiation just as effective?

PURPOSE: The purpose of this paper is to study long-term oncologic outcomes after different treatment strategies for anal canal cancer (SCAC). METHODS: Patients with SCAC (2004-2013) were identified from Surveillance, Epidemiology, and End Results (SEER) database. Patients undergoing radiation (RT) were compared to those undergoing local excision (LE), abdominoperineal resection (APR), and abdominoperineal resection after radiation (RT + APR). Overall survival (OS) and cancer-specific survival (CSS) data were evaluated using Kaplan-Meier and Cox regression. RESULTS: Two thousand seven hundred and seventy-two (83.8%) patients underwent RT, 382 (11.6%) LE, 77 (2.3%) APR, 76 (2.3%) RT + APR. Median age for the four groups was 60, 57, 64, and 56 years and 32, 49.7, 53.2, and 39.5% were male, respectively, while median tumor size was 4.4, 2.6, 5.3, and 5.5 cm, respectively. Five-year OS of RT, LE, APR, and RT + APR groups was 63.7, 79.6, 25.8, and 41.8% while CSS was 79.6, 92.5, 75.6, and 58.8%, respectively, (p < 0.001). Adjusted hazard ratios for OS for LE, APR, and RT + APR with RT as reference were 1.007 (0.702-1.444), 2.311 (1.367-3.906), and 2.072 (1.016-4.228), respectively. CONCLUSION: These data suggest that APR does not provide better outcomes in treatment of SCAC. Chemoradiation remains the gold standard treatment for majority of patients. Local excision is associated with favorable outcomes in some circumstances.

Switchable beam steering with zenithal bistable liquid-crystal blazed gratings.

Switchable beam steerers based on zenithal bistable liquid crystal (LC) gratings are designed and theoretically investigated. The nematic orientation profiles and the optical transmittance properties of the gratings are rigorously calculated, respectively, via a tensorial formulation of the Landau-de Gennes theory and the full-wave finite-element-method. By proper design of the grating geometry, beam steering with high diffraction efficiency is demonstrated between the two stable LC states. The tolerance of the device performance with respect to material parameters is assessed, evidencing spectral operation windows of more than 50 nm in the visible for a beam steering efficiency higher than 90%.

Silicon-loaded surface plasmon polariton waveguides for nanosecond thermo-optical switching.

A MHz-bandwidth thermo-optical (TO) plasmonic switch operating at telecommunication wavelengths and based on a hybrid solid-state silicon-loaded surface plasmon polariton waveguide design is demonstrated numerically. The nanosecond (ns) TO response of the switch is due to the high thermal conductivities of the employed materials and we demonstrate specifically a 10 dB extinction ratio in the time-dependent switch transmission which features a pulsed 1 ns rise time followed by a 25 ns fall time when the switch is photo-thermally activated by a ns pulse at 532 nm wavelength.

Dietary habits and supplement use in relation to national pregnancy recommendations: data from the EuroPrevall birth cohort.

Assessing maternal dietary habits across Europe during pregnancy in relation to their national pregnancy recommendations. A collaborative, multi-centre, birth cohort study in nine European countries was conducted as part of European Union funded EuroPrevall project. Standardised baseline questionnaire data included details of food intake, nutritional supplement use, exposure to cigarette smoke during pregnancy and socio-demographic data. Pregnancy recommendations were collected from all nine countries from the appropriate national organisations. The most commonly taken supplement in pregnancy was folic acid (55.6 % Lithuania-97.8 % Spain) and was favoured by older, well-educated mothers. Vitamin D supplementation across the cohort was very poor (0.3 % Spain-5.1 % Lithuania). There were significant differences in foods consumed in different countries during pregnancy e.g. only 2.7 % Dutch mothers avoided eating peanut, while 44.4 % of British mothers avoided it. Some countries have minimal pregnancy recommendations i.e. Lithuania, Poland and Spain while others have similar, very specific recommendations i.e. UK, the Netherlands, Iceland, Greece. Allergy specific recommendations were associated with food avoidance during pregnancy [relative rate (RR) 1.18 95 % CI 0.02-1.37]. Nutritional supplement recommendations were also associated with avoidance (RR 1.08, 1.00-1.16). Maternal dietary habits and the use of dietary supplements during pregnancy vary significantly across Europe and in some instances may be influenced by national recommendations.

Dual-band electro-optic polarization switch based on dual-core liquid-crystal photonic crystal fibers.

Compact voltage-controlled all-in-fiber polarization switches are designed and investigated based on dual-core photonic crystal fibers, by selectively infiltrating one of the fiber's cores with a nematic liquid crystal. The electro-optical control of the liquid crystal core's optical properties allows for the splitting of the two orthogonal polarizations, showing crosstalk values lower than -20 dB in a 40 nm window at 1550 nm, for an ultracompact length less than 0.6 mm. With proper selection of the control voltage and the component length, dual-band operation with a crosstalk lower than -20 dB is also demonstrated for the 1300 and 1550 nm telecom bands.

Prospective Series of Transarterial Chemoembolization of Metastatic Colorectal Cancer to the Liver with 30-60 µm Microspheres Loaded with Irinotecan.

PURPOSE: To describe safety and clinical outcomes among patients with metastatic colorectal cancer (mCRC) to the liver treated with transarterial chemoembolization with HepaSphere™ Microspheres 30-60 µm loaded with irinotecan (ΙRI-HEP-TACE). MATERIAL AND METHODS: In this prospective study (NCT04866290), 100 adults with confirmed mCRC to the liver who were ineligible for resection were enrolled and followed up to 24 months or death. Study outcomes among Salvage (patients not tolerating more cycles of chemotherapy) and Non-salvage patients included overall survival (OS), progression-free survival (PFS), objective response (OR), objective response rate (ORR), best tumor response (BTR), adverse events (AEs), and pharmacokinetics of irinotecan and its active metabolite, 7-ethyl-10-hydroxy-camptothecin (SN38). RESULTS: The median age was 66 years (range: 31-89). Median OS was 15.08 months (95% confidence interval [CI]: 12.33-17.25). PFS was 8.52 months (95% CI: 6.0-9.0; p < 0.001). ORR was 42.2% (95% CI: 31.57-53.50) and 35.9% (95% CI: 25.57-47.62) based on modified RECIST (Response Evaluation Criteria in Solid Tumors) and RECIST 1.1 criteria. BTR was not significantly different between mRECIST and RECIST (p = 0.745). The Non-salvage group had a statistically significant difference in median OS relative to the Salvage group (15.3 vs. 3 months; p < 0.001). Pharmacokinetic analyses demonstrated no correlation of OS with plasma concentration of irinotecan and SN38 (all p > 0.05). Most AEs were Grade 2 (257/279), the most common AE was right upper abdominal pain (180/279). One major AE (tumor rupture) was reported. CONCLUSION: IRI-HEP-TACE is an alternative treatment for patients with Non-salvage mCRC to the liver.

High-Resolution Melting (HRM) Analysis for Rapid Molecular Identification of Sparidae Species in the Greek Fish Market.

The red porgy (Pagrus pagrus) and the common dentex (Dentex dentex) are Sparidae species of high commercial value, traded in the Greek market. In some cases, fish species identification from Greek fisheries is difficult for the consumer due to the strong morphological similarities with their imported counterparts or closely related species such as Pagrus major, Pagrus caeroleustictus, Dentex gibbosus and Pagellus erythrinus, especially when specimens are frozen, filleted or cooked. Techniques based on DNA sequencing, such as COI barcoding, accurately identify species substitution incidents; however, they are time consuming and expensive. In this study, regions of mtDNA were analyzed with RFLPs, multiplex PCR and HRM in order to develop a rapid method for species identification within the Sparidae family. HRM analysis of a 113 bp region of cytb and/or a 156 bp region of 16s could discriminate raw or cooked samples of P. pagrus and D. dentex from the aforementioned closely related species and P. pagrus specimens sampled in the Mediterranean Sea when compared to those fished in the eastern Atlantic. HRM analysis exhibited high accuracy and repeatability, revealing incidents of mislabeling. Multiple samples can be analyzed within three hours, rendering this method a useful tool in fish fraud monitoring.

West Nile Disease Symptoms and Comorbidities: A Systematic Review and Analysis of Cases.

West Nile virus (WNV) is a mosquito-borne flavivirus that has emerged as a major cause of viral encephalitis and meningitis, rarely leading to death. Several risk factors have been discussed in the past concerning the severity of the disease, while few reports have focused on precipitating conditions that determine of WNV-related death. Studies on cohorts of patients suffering of West Nile disease (WND) usually encompass low numbers of deceased patients as a result of the rarity of the event. In this systematic review and critical analysis of 428 published case studies and case series, we sought to evaluate and highlight critical parameters of WND-related death. We summarized the symptoms, comorbidities, and treatment strategies related to WND in all published cases of patients that included clinical features. Symptoms such as altered mental status and renal problems presented increased incidence among deceased patients, while these patients presented increased cerebrospinal fluid (CSF) glucose. Our analysis also highlights underestimated comorbidities such as pulmonary disease to act as precipitating conditions in WND, as they were significantly increased amongst deceased patients. CSF glucose and the role of pulmonary diseases need to be revaluated either retrospectively or prospectively in WND patient cohorts, as they may be linked to increased mortality risk.

Diffraction grating with suppressed zero order fabricated using dielectric forces.

An electric-field-assisted method to produce diffractive optical devices is demonstrated. A uniform film of liquid UV curable resin was produced as a drying ring from an organic solvent. Dielectrophoresis forces maintained the stability of the thin film and also imprinted a periodic corrugation deformation of pitch 20 µm on the film surface. Continuous in situ voltage-controlled adjustment of the optical diffraction pattern was carried out simultaneously with UV curing. A fully cured solid phase grating was produced with the particular voltage-selected tailored optical property that the zero transmitted order was suppressed for laser light at 633 nm.

Malpigmentation of Common Sole (Solea solea) during Metamorphosis Is Associated with Differential Synaptic-Related Gene Expression.

In farmed flatfish, such as common sole, color disturbances are common. Dyschromia is a general term that includes the color defects on the blind and ocular sides of the fish. The purpose was to examine the difference in gene expression between normal pigmented and juveniles who present ambicoloration. The analysis was carried out with next-generation sequencing techniques and de novo assembly of the transcriptome. Transcripts that showed significant differences (FDR < 0.05) in the expression between the two groups, were related to those of zebrafish (Danio rerio), functionally identified, and classified into categories of the gene ontology. The results revealed that ambicolorated juveniles exhibit a divergent function, mainly of the central nervous system at the synaptic level, as well as the ionic channels. The close association of chromophore cells with the growth of nerve cells and the nervous system was recorded. The pathway, glutamate binding-activation of AMPA and NMDA receptors-long-term stimulation of postsynaptic potential-LTP (long term potentiation)-plasticity of synapses, appears to be affected. In addition, the development of synapses also seems to be affected by the interaction of the LGI (leucine-rich glioma inactivated) protein family with the ADAM (a disintegrin and metalloprotease) ones.

Explicit finite-difference vector beam propagation method based on the iterated Crank-Nicolson scheme.

We introduce and develop a new explicit vector beam propagation method, based on the iterated Crank-Nicolson scheme, which is an established numerical method in the area of computational relativity. The proposed approach results in a fast and robust method, characterized by simplicity, efficiency, and versatility. It is free of limitations inherent in implicit beam propagation methods, which are associated with poor convergence or uneconomical use of memory in the solution of large sparse linear systems, and thus it can tackle problems of considerable size and complexity. The advantages offered by this approach are demonstrated by analyzing a multimode interference coupler and a twin-core photonic crystal fiber. A possible wide-angle generalization is also provided.

Heterozygosity fitness correlations and generation interval of the Norway lobster in the Aegean Sea, eastern Mediterranean.

BACKGROUND: Comprehensively detailed information on population dynamics for benthic species is crucial since potential admixture of individuals could shift the genetic subdivision and age structure during a full breeding period. The apparent genetic impact of the potential recruitment strategy of Norway lobster Nephrops norvegicus is still under research. For this reason the present study was focused on genetic variation of the species over a given continuous year period in a semi-enclosed gulf of the Aegean Sea. RESULTS: Analyses revealed that the relative smaller size class in females and the apparent faster growth of males may represent a key-role differential strategy for the two sexes, whereas females tend to mature slower. Heterozygosity fitness correlations (HFCs) showed substantially significant associations suggesting that inbreeding depression for females and outbreeding depression for males are the proximate fitness mechanisms, respectively. CONCLUSIONS: Nephrops norvegicus uniformal genetic composition (background of high gene flow), could be attributed to potential population recolonization, due to a hypothesized passive larval movement from deeper waters, which may suggest that some offspring of local residents and potential male non-breeders from other regions admixture randomly.

Hox Genes Polymorphism Depicts Developmental Disruption of Common Sole Eggs.

In sole aquaculture production, consistency in the quality of produced eggs throughout the year is unpredictable. Hox genes have a crucial role in controlling embryonic development and their genetic variation could alter the phenotype dramatically. In teleosts genome duplication led paralog hox genes to become diverged. Direct association of polymorphism in hoxa1a, hoxa2a & hoxa2b of Solea solea with egg viability indicates hoxa2b as a potential genetic marker. High Resolution Melt (HRM) analysis was carried out in 52 viable and 61 non-viable eggs collected at 54±6 hours post fertilization (hpf). Allelic and genotypic frequencies of polymorphism were analyzed and results illustrated a significantly increased risk for non-viability for minor alleles and their homozygous genotypes. Haplotype analysis demonstrated a significant recessive effect on the risk of non-viability, by increasing the odds of disrupting embryonic development up to three-fold. Phylogenetic analysis showed that the paralog genes hoxa2a and hoxa2b, are separated distinctly in two clades and presented a significant ω variation, revealing their diverged evolutionary rate.

Five-Years Outcome Analysis of 142 Consecutive Hepatocellular Carcinoma Patients Treated with Doxorubicin Eluting Microspheres 30-60 µm: Results from a Single-Centre Prospective Phase II Trial.

PURPOSE: To assess prospectively long-term results of doxorubicin-loaded HepaSphere 30-60 µm in consecutive patients with hepatocellular carcinoma (HCC) not amenable to curative treatments. PATIENTS AND METHODS: Single-center study from June 2011 to December 2015 in 151 patients treated with 75 mg of doxorubicin per HepaSphere vial. Baseline: Barcelona Clinic Liver Cancer BCLC A/B was 49.3%/50.7%, and median diameter 6.1 cm (mean 6.7 ± 2.0). Liver function, local response (mRECIST), liver time to progression (LTTP), progression-free survival (PFS), overall survival (OS) and adverse events (AEs) were recorded. RESULTS: Final analysis included 142 patients with median follow-up of 46.8 months (range 4-72) without grade 4/5 AEs, and 30-day mortality was 0%. Mean number of scheduled treatments was 2.6 (range 1-3) and on demand 3 (range 1-8). Complete response for single tumor ≤ 5 cm was 75.0% and 66.7% for Child A and Child B, while for > 5 cm was 28.6% and 11.8%, respectively. OS was 31.0 months (mean 33.3 ± 15.2; range 8-69), notably for BCLC A 41 months (mean 41.1 ± 15.3; range 13-69) and for BCLC B 26.0 (mean 26.0 ± 10.5; range 8-51). OS at 1, 3 and 5 years: 95.8%, 75.7% and 21.4% for BCLC A, and 94.4%, 36.1% and 2.7% for BCLC B. Median LTTP for BCLC A was 11 months (mean 11.9 ± 4.7; range 3-24) and 7.5 for BCLC B (mean 7.9 ± 2.9). Local response was significant for OS and LTTP (p < 0.0001), while size and lesion number affected LPFS and OS (p < 0.001). CONCLUSIONS: HepaSphere 30-60 µm loaded with doxorubicin provides a safe and effective treatment option for patients with HCC.

Theoretical and experimental optical studies of cholesteric liquid crystal films with thermally induced pitch gradients.

The reflection properties of cholesteric films with thermally induced pitch gradients are theoretically and experimentally studied. It is shown that the optical behavior of such films corresponds to the averaged contribution of a number of stochastic pitch variation profiles, due to the transversal and longitudinal nonuniformities that develop in the helical structure of such samples. Depending on the annealing time, both narrow-band and broadband behavior can be selectively achieved. The influence of the pitch profile gradient on the broadband reflection performance of cholesteric samples is theoretically analyzed, and a multi-slab structure for achieving optimum efficiency is proposed.

Coupled-mode-theory framework for nonlinear resonators comprising graphene.

A general framework combining perturbation theory and coupled-mode theory is developed for analyzing nonlinear resonant structures comprising dispersive bulk and sheet materials. To allow for conductive sheet materials, a nonlinear current term is introduced in the formulation in addition to the more common nonlinear polarization. The framework is applied to model bistability in a graphene-based traveling-wave resonator system exhibiting third-order nonlinearity. We show that the complex conductivity of graphene disturbs the equality of electric and magnetic energies on resonance (a condition typically taken for granted), due to the reactive power associated with the imaginary part of graphene's surface conductivity. Furthermore, we demonstrate that the dispersive nature of conductive materials must always be taken into account, since it significantly impacts the nonlinear response. This is explained in terms of the energy stored in the surface current, which is zeroed-out when linear dispersion is neglected. The results obtained with the proposed framework are compared with full-wave nonlinear finite-element simulations with excellent agreement. Very low characteristic power for bistability is obtained, indicating the potential of graphene for nonlinear applications.

Beam-splitter switches based on zenithal bistable liquid-crystal gratings.

The tunable optical diffractive properties of zenithal bistable nematic liquid-crystal gratings are theoretically investigated. The liquid-crystal orientation is rigorously solved via a tensorial formulation of the Landau-de Gennes theory and the optical transmission properties of the gratings are investigated via full-wave finite-element frequency-domain simulations. It is demonstrated that by proper design the two stable states of the grating can provide nondiffracting and diffracting operation, the latter with equal power splitting among different diffraction orders. An electro-optic switching mechanism, based on dual-frequency nematic materials, and its temporal dynamics are further discussed. Such gratings provide a solution towards tunable beam-steering and beam-splitting components with extremely low power consumption.

Use of GnRH analogues pre-operatively for hysteroscopic resection of submucous fibroids: a systematic review and meta-analysis.

GnRH analogues are commonly used before hysteroscopic myomectomy to make surgery easier and safer, but they are expensive, have potential side effects and lack a robust evidence base to support this practice. We undertook a systematic review of the literature to determine whether, in women with submucous fibroids, pre-operative GnRH analogues were more effective than placebo/no treatment in terms of symptom relief, complications and ease of surgery. The outcomes were patient-reported relief of symptoms, complete resection of the fibroids, operative time and complications. Meta-analysis was performed where appropriate. Two trials including 86 women were identified. The assessment of symptom relief differed in the two trials: hence it was not possible to combine these data. The relative risk for completion of surgery and mean differences (95% confidence intervals) for operating time and fluid deficit were [0.94 (0.68-1.31); -5.34 min, (-7.55 min to -3.12 min) and -176.2 ml, (-281.05 ml to -71.5 ml)] respectively. Our results suggest that GnRHa may improve some outcomes but there is insufficient evidence to support their routine use prior to hysteroscopic resection of submucous fibroids. More randomised trials are needed to inform definitive conclusions.