Optimization of sub-relativistic co-propagating accelerating structures

In this paper, novel optimization methodologies of sub-relativistic guided interaction structures for dielectric laser particle acceleration (DLA) are presented. In particular, we focus on co-propagating geometries based on slot waveguides in continuous wave (CW) operation, where the particle flow and the direction of propagation of the accelerating field are co-linear. Since the velocity of sub-relativistic particles varies along the acceleration path, proper tapering of the waveguide geometry is required to achieve an extended acceleration region, and, thus a large energy gain. The design of an optimal taper ensuring particle-wave synchronicity and maximum energy gain is pursued through a physics-based approach, and these results are compared, for validation, with the outcomes of a downhill simplex method searching algorithm. Additionally, the application of a simplified 2D model of the accelerating slot waveguide is investigated and profitably used to get qualitative results useful for fast structure optimization. Indeed, this approach can hold significant potential for the development of novel accelerating structures, as it enables a thorough and fast exploration of the design space.

Evaluation of COVID-19 impact on DELAYing diagnostic-therapeutic pathways of lung cancer patients in Italy (COVID-DELAY study): fewer cases and higher stages from a real-world scenario

Introduction

COVID-19 has disrupted the global health care system since March 2020. Lung cancer (LC) patients (pts) represent a vulnerable population highly affected by the pandemic. This multicenter Italian study aimed to evaluate whether the COVID-19 outbreak had an impact on access to cancer diagnosis and treatment of LC pts compared with pre-pandemic time.

Methods

Consecutive newly diagnosed LC pts referred to 25 Italian Oncology Departments between March and December 2020 were included. Access rate and temporal intervals between date of symptoms onset and diagnostic and therapeutic services were compared with the same period in 2019. Differences between the 2 years were analyzed using the chi-square test for categorical variables and the Mann–Whitney U test for continuous variables.

Results

A slight reduction (−6.9%) in newly diagnosed LC cases was observed in 2020 compared with 2019 (1523 versus 1637, P = 0.09). Newly diagnosed LC pts in 2020 were more likely to be diagnosed with stage IV disease (P < 0.01) and to be current smokers (someone who has smoked more than 100 cigarettes, including hand-rolled cigarettes, cigars, cigarillos, in their lifetime and has smoked in the last 28 days) (P < 0.01). The drop in terms of new diagnoses was greater in the lockdown period (percentage drop −12% versus −3.2%) compared with the other months included. More LC pts were referred to a low/medium volume hospital in 2020 compared with 2019 (P = 0.01). No differences emerged in terms of interval between symptoms onset and radiological diagnosis (P = 0.94), symptoms onset and cytohistological diagnosis (P = 0.92), symptoms onset and treatment start (P = 0.40), and treatment start and first radiological revaluation (P = 0.36).

Conclusions

Our study pointed out a reduction of new diagnoses with a shift towards higher stage at diagnosis for LC pts in 2020. Despite this, the measures adopted by Italian Oncology Departments ensured the maintenance of the diagnostic-therapeutic pathways of LC pts.

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The COVID-19 outbreak had an impact on access to lung cancer (LC) diagnosis and treatment.

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A slight reduction (−6.9%) in newly diagnosed LC cases was observed in 2020 compared with 2019.

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Newly diagnosed LC pts in 2020 were more likely to be diagnosed with stage IV disease.

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The Italian Oncology Departments ensured the maintenance of the diagnostic-therapeutic pathways of LC pts.

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A reverse migration from high-volume to low-volume cancer centers was noted during the pandemic.

Monolithic AlGaAs second-harmonic nanoantennas: erratum

Figure 1(b) in [V. F. Gili et al, Opt. Express24, 15965 (2016)10.1364/OE.24.015965] is corrupted and is corrected in this erratum.

The lung immuno-oncology prognostic score (LIPS-3): a prognostic classification of patients receiving first-line pembrolizumab for PD-L1 ≥ 50% advanced non-small-cell lung cancer

Background

To stratify the prognosis of patients with programmed cell death-ligand 1 (PD-L1) ≥ 50% advanced non-small-cell lung cancer (aNSCLC) treated with first-line immunotherapy.

Methods

Baseline clinical prognostic factors, the neutrophil-to-lymphocyte ratio (NLR), PD-L1 tumour cell expression level, lactate dehydrogenase (LDH) and their combination were investigated by a retrospective analysis of 784 patients divided between statistically powered training (n = 201) and validation (n = 583) cohorts. Cut-offs were explored by receiver operating characteristic (ROC) curves and a risk model built with validated independent factors by multivariate analysis.

Results

NLR < 4 was a significant prognostic factor in both cohorts (P < 0.001). It represented 53% of patients in the validation cohort, with 1-year overall survival (OS) of 76.6% versus 44.8% with NLR > 4, in the validation series. The addition of PD-L1 ≥ 80% (21% of patients) or LDH < 252 U/l (25%) to NLR < 4 did not result in better 1-year OS (of 72.6% and 74.1%, respectively, in the validation cohort). Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 2 [P < 0.001, hazard ratio (HR) 2.04], pretreatment steroids (P < 0.001, HR 1.67) and NLR < 4 (P < 0.001, HR 2.29) resulted in independent prognostic factors. A risk model with these three factors, namely, the lung immuno-oncology prognostic score (LIPS)-3, accurately stratified three OS risk-validated categories of patients: favourable (0 risk factors, 40%, 1-year OS of 78.2% in the whole series), intermediate (1 or 2 risk factors, 54%, 1-year OS 53.8%) and poor (>2 risk factors, 5%, 1-year OS 10.7%) prognosis.

Conclusions

We advocate the use of LIPS-3 as an easy-to-assess and inexpensive adjuvant prognostic tool for patients with PD-L1 ≥ 50% aNSCLC.

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Immunotherapy/chemoimmunotherapy combinations are currently not superior to immunotherapy alone for high PD-L1 aNSCLC.

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NLR with a cut-off of 4 was validated as an independent prognostic factor for immunotherapy in high PD-L1 aNSCLC.

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The addition of either PD-L1 ≥ 80% or LDH < 252 U/l to NLR < 4 did not result in better prognostic stratification.

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The LIPS-3 is a validated 3-class prognostic classification based on the NLR, ECOG PS and pretreatment steroids.

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The LIPS-3 is a routinely assessable adjuvant prognostic tool for high PD-L1 aNSCLC patients.

Straight Versus Branched Chain Substituents in 4′-(Butoxyphenyl)-3,2′:6′,3″-terpyridines: Effects on (4,4) Coordination Network Assemblies

The preparation and characterization of the isomers rac-4′-(4-butan-2-yloxyphenyl)-3,2′:6′,3″-terpyridine (rac-2), 4′-(2-methylpropoxyphenyl)-3,2′:6′,3″-terpyridine (3) and 4′-(tert-butoxyphenyl)-3,2′:6′,3″-terpyridine (4) are reported. The compounds react with Co(NCS)₂ under conditions of crystal growth at room temperature to give single crystals of [{Co(rac-2)₂(NCS)₂}·CHCl₃]_n, [Co(3)₂(NCS)₂]_n and [{Co(4)₂(NCS)₂}·CHCl₃]_n which possess (4,4) networks, with the Co centers acting as 4-connecting nodes. Powder X-ray diffraction (PXRD) was used to confirm that the crystals chosen for single crystal X-ray diffraction were representative of the bulk samples. The detailed structures of the three networks have been compared with that of the previously reported [{Co(1)₂(NCS)₂}·4CHCl₃]n in which 1 is 4′-(butoxyphenyl)-3,2′:6′,3″-terpyridine. Whereas the switch from 1 with the straight-chain butoxy substituent to rac-2, 3 and 4 with branched chains causes significant structural perturbation, changes in the spatial properties of the branched substituents are accommodated with subtle conformational changes in the 3,2′:6′,3″-tpy domain.

Anticancer Potential of Diiron Vinyliminium Complexes

Invited for the cover of this issue is the group of Fabio Marchetti at the Università di Pisa and Paul J. Dyson at Ecole Polytechnique Fédérale de Lausanne (EPFL). Read the full text of the article at 10.1002/chem.201902885.

Anticancer Potential of Diiron Vinyliminium Complexes

Although ferrocene derivatives have attracted considerable attention as possible anticancer agents, the medicinal potential of diiron complexes has remained largely unexplored. Herein, we describe the straightforward multigram-scale synthesis and the antiproliferative activity of a series of diiron cyclopentadienyl complexes containing bridging vinyliminium ligands. IC₅₀ values in the low-to-mid micromolar range were determined against cisplatin sensitive and resistant human ovarian carcinoma (A2780 and A2780cisR) cell lines. Notable selectivity towards the cancerous cells lines compared to the non-tumoral human embryonic kidney (HEK-293) cell line was observed for selected compounds. The activity seems to be multimodal, involving reactive oxygen species (ROS) generation and, in some cases, a fragmentation process to afford monoiron derivatives. The large structural variability, amphiphilic character and good stability in aqueous media of the diiron vinyliminium complexes provide favorable properties compared to other widely studied classes of iron-based anticancer candidates.

Synthesis of Terpyridines: Simple Reactions-What Could Possibly Go Wrong?

The preparation of 2⁴-functionalized 1²,2²:2⁶,3²-terpyridines (4′-functionalized 3,2:6′,3″-terpyridines) by the reaction of three 4-alkoxybenzaldehydes with 3-acetylpyridine and ammonia was investigated; under identical reaction conditions, two (R =ⁿC₄H₉, C₂H₅) gave the expected products whereas a third (R = ⁿC₃H₇) gave only a cyclohexanol derivative derived from the condensation of three molecules of 3-acetylpyridine with two of 4-(n-propoxy)benzaldehyde. A comprehensive survey of “unexpected” products from reactions of ArCOCH₃ derivatives with aromatic aldehydes is presented. Three different types of alternative product are identified.

Measurement of the Neutrino Mixing Angle θ_{23} in NOvA

This Letter reports new results on muon neutrino disappearance from NOvA, using a 14 kton detector equivalent exposure of 6.05×10^{20} protons on target from the NuMI beam at the Fermi National Accelerator Laboratory. The measurement probes the muon-tau symmetry hypothesis that requires maximal θ_{23} mixing (θ_{23}=π/4). Assuming the normal mass hierarchy, we find Δm_{32}^{2}=(2.67±0.11)×10^{-3}  eV^{2} and sin^{2}θ_{23} at the two statistically degenerate values 0.404_{-0.022}^{+0.030} and 0.624_{-0.030}^{+0.022}, both at the 68% confidence level. Our data disfavor the maximal mixing scenario with 2.6σ significance.

Controlling second-harmonic generation at the nanoscale with monolithic AlGaAs-on-AlOx antennas

We review recent achievements in the field of nanoscale nonlinear AlGaAs photonics based on all-dielectric optical antennas. After discussing the motivation and main technological challenges for the development of an AlGaAs monolithic platform for χ ⁽²⁾ nonlinear nanophotonics, we present numerical and experimental investigations of the second-order nonlinear response and physical reasons for high efficiency of second-order nonlinear interactions in the AlGaAs nano-antennas. In particular, we emphasize the role of the dipolar resonances at the fundamental frequency and the multipolar resonances at the second harmonic wavelength. We also discuss second-harmonic generation directionality and show possible strategies to engineer the radiation pattern of nonlinear antennas.

Polarization properties of second-harmonic generation in AlGaAs optical nanoantennas

Manipulating light at the nanoscale by means of dielectric nanoantennas recently received renewed attention thanks to the development of key enabling fabrication tools in semiconductor technology, combined with the extremely low losses exhibited by dielectrics in the optical regime. Nanostructures based on III-V type semiconductors, characterized by an intrinsic broken symmetry down to a single elementary cell, has already demonstrated remarkable nonlinear conversion efficiencies at scales well below the operating wavelength. In this Letter, we thoroughly investigate the emission properties of second-harmonic generation (SHG) in AlGaAs monolithic nanoantennas. Our findings point toward the pivotal role of volume susceptibility in SHG, further unraveling the physics behind the nonlinear processes in these systems. The extremely high SHG efficiency attained, together with the control over the polarized emission in these nanoantennas, constitute key ingredients for the development of tunable nonlinear metasurfaces.

Monolithic AlGaAs second-harmonic nanoantennas

We demonstrate monolithic aluminum gallium arsenide (AlGaAs) optical nanoantennas. Using a selective oxidation technique, we fabricated epitaxial semiconductor nanocylinders on an aluminum oxide substrate. Second harmonic generation from AlGaAs nanocylinders of 400 nm height and varying radius pumped with femtosecond pulses delivered at 1554-nm wavelength has been measured, revealing a peak conversion efficiency exceeding 10^-5 for nanocylinders with an optimized geometry.

First Measurement of Electron Neutrino Appearance in NOvA

We report results from the first search for ν_{μ}→ν_{e} transitions by the NOvA experiment. In an exposure equivalent to 2.74×10^{20} protons on target in the upgraded NuMI beam at Fermilab, we observe 6 events in the Far Detector, compared to a background expectation of 0.99±0.11(syst) events based on the Near Detector measurement. A secondary analysis observes 11 events with a background of 1.07±0.14(syst). The 3.3σ excess of events observed in the primary analysis disfavors 0.1π<δ_{CP}<0.5π in the inverted mass hierarchy at the 90% C.L.

The involvement of oxidative stress in bovine herpesvirus type 4-mediated apoptosis

Bovine herpesvirus type 4 (BHV-4) belongs to the gamma-2-herpesviruses of the Gammaherpesvirinae subfamily. BHV-4 has a worldwide distribution and has been isolated in a variety of clinical diseases as well as from healthy cattle. In this report we demonstrate that BHV-4 induces apoptosis in MDBK cells. In the early phases of apoptosis, cells show an increase in the intracellular level of reactive oxygen species, which is indicative of oxidative stress. This precedes DNA fragmentation, a hallmark typical of apoptosis. Cells were protected from apoptosis only by certain antioxidants (butylated hydroxyanisole and ebselen), whereas N-acetylcysteine turned out to be ineffective. Antioxidants that protected cells from apoptosis prevented oxidative stress but failed to block virus growth. These observations suggest that oxidative stress may be a crucial event in the sequence leading to apoptotic cell death but apoptosis is not required for the multiplication of BHV-4.

Type III Ehlers-Danlos syndrome: correlations among clinical signs, ultrasound, and histologic findings in a study of 35 cases

BACKGROUND

Patients with type III Ehlers-Danlos syndrome show hypermobile joints, luxation, and minimal atrophic scars. The disease has an incidence of 9-16% and the molecular defect that underlies this subtype is unknown. In order to widen diagnostic investigations in type III Ehlers-Danlos syndrome, skin and articular areas were studied by ultrasound (US) test.

METHODS

Thirty-five patients, 20 women and 15 men, aged from 18 to 25 years, with type III Ehlers-Danlos syndrome were enrolled in this study. Patients showed hypermobile joints (35 cases), minimal atrophic wrinkled scars (35 cases), and a few ice-pick acne scars. Hypermobility of phalangeal joints was studied by means of the Beighton scoring system and by a US test (performed by Sonora Logic 400 MD unit with 10 MHz probe). The following US parameters were considered: the distance of the intra-articular space and the thicknesses of the extensor tendon and of the overhanging dermis and subcutis.

RESULT

US reports showed an increase in distance of the intra-articular space and a reduction in the thickness of the extensor tendon and of the dermis and subcutis covering it. The dermis showed high and homogeneous echogenicity with irregular hyperechogenic lines.

CONCLUSION

The Beighton scoring system, the US findings, and the aspect and diameter of the scars suggested that the disease can be divided into three different stages which allow the correlation, over progressive intervals of values, of the articular hypermobility and atrophic wrinkled scars. Our results showed that US test is able to confirm the clinical diagnosis and to evaluate the seriousness of hypermobile joints.

Carotid artery pseudoaneurysm as a complication of ECMO

Any pulsatile neck mass after extracorporeal membrane oxygenation (ECMO) must be viewed as a pseudoaneurysm of the carotid artery until proven otherwise. Prompt diagnosis is necessary utilizing ultrasound. Angiography may not be necessary. Carotid artery pseudoaneurysm requires urgent surgical intervention to prevent catastrophic hemorrhage. The utilization of cardiopulmonary bypass may facilitate safe repair.

Prospective, randomized, double-blind study of high-dose aprotinin in pediatric cardiac operations

BACKGROUND

Perioperative aprotinin decreases postoperative blood loss in adults undergoing cardiac operations, but its role is less clear in children. Therefore, a trial of aprotinin in pediatric cardiac operations was conducted to study the efficacy of its use in children.

METHODS

Forty-two patients were randomly assigned to receive either high-dose aprotinin or placebo. Aprotinin efficacy was assessed using time from protamine administration to skin closure, postoperative blood loss and hemoglobin loss, and postoperative transfusion requirements. Measures of fibrinolysis (fibrin degradation product titers) and platelet preservation (beta-thromboglobulin levels) were also assessed.

RESULTS

There were no statistically significant differences between groups in any of the blood loss or transfusion parameters. Fibrin degradation product levels, measured 4 hours postoperatively, had increased significantly for control patients, but remained unchanged for the aprotinin group (p < 0.02). beta-Thromboglobulin levels increased more rapidly during cardiopulmonary bypass in the control group (p = 0.03).

CONCLUSIONS

Aprotinin appears to provide no clinical benefit in routine pediatric cardiac operations. A reduction in fibrinolysis, with perhaps an early preservation of platelet structure, is seen in the aprotinin group.

[Etiology and incidence of pure mitral insufficiency: a morphological study of 926 native valves]

From July 1981 to October 1988, 1597 native valves, 926 (58%) mitral and 671 (42%) aortic, were excised. The gross and histological features of all valves were studied using routine histochemical, immunohistochemical and electron microscopy techniques. As far as mitral valve is concerned the lesions were: stenosis 263 (28.6%), stenosis + incompetence 537 (57.8%) and incompetence 126 (13.6%). Our study was limited to the valves of patients undergoing mitral valve replacement because of pure incompetence. The pathological alterations of the valves were: floppy mitral valve (FMV) 59 (46.8%), rheumatic disease (RD) 50 (39.6%), infective endocarditis (IE) 13 (10.3%), papillary muscles ischemic disease (PMID) 4 (3.1%). In the FMV group the associated lesions were: aortic valve incompetence due to floppy aortic valve and noninflammatory aortic root disease (9-15.2%), tricuspid valve incompetence (4-7.8%) and atrial septal defect (7-13.7%). The commonest complication in this group was rupture of chordae tendineae requiring urgent surgery. In the RD group there was a high incidence of active rheumatism, valvulitis and papillary muscles myocarditis (37-74%) despite the laboratory data were within normal ranges. In the IE group there was an associated aortic endocarditis in 7 patients (53.8%). The FMV was the commonest cause of pure incompetence in patients who had mitral valve replacement. Rheumatic pure mitral incompetence was always associated in our experience to signs of active rheumatic disease.

Modulation of age-related changes in serum 1,25-dihydroxyvitamin D and parathyroid hormone by dietary restriction of Fischer 344 rats

The purpose of this study was to determine the effect of food restriction on age-related changes in serum 1,25-dihydroxyvitamin D and PTH, two important regulators of Ca metabolism. Starting at 6 wk, male F344 rats were fed a purified diet either ad libitum (non-restricted) or 60% of ad libitum (restricted). Rats from each group were killed at 5, 13, 22 and 28 mo of age. Dietary restriction increased the median lifespan from 24 to 31 mo. It delayed the rapid decrease in serum 1,25-dihydroxyvitamin D from 1.5-5.0 mo in the non-restricted group to 5-13 mo in the restricted group. It also completely suppressed the marked rise in serum PTH which occurred at 22 and 28 mo in the non-restricted group. Dietary restriction had these effects even though both groups of animals consumed the same amount of Ca per gram body weight. Diet had no effect on serum Ca and P, except at 28 mo. These effects of dietary restriction on serum 1,25-dihydroxyvitamin D and PTH may result in altered Ca metabolism in dietary restricted F344 rats.

Chronic ethanol consumption and aging: changes in lipid composition of liver microsomes

Both aging and chronic ethanol consumption have been found to produce changes in lipid composition. Severity of intoxication, withdrawal and release of gamma-aminobutyric acid following chronic ethanol consumption have been shown to be associated with age. It was predicted in this study that aged mice would differ in response to ethanol-induced changes in lipid composition of liver microsomes as compared to younger mice. Two different age groups of C57BL/6NNIA male mice (6 and 28 months) were administered an ethanol or control liquid diet for 24 days. Liver microsomes were prepared on Day 25. Age and ethanol consumption significantly affected liver weight and the ratio of liver weight to body weight. PC significantly decreased and PE significantly increased in both the young and old ethanol groups. Cholesterol and total phospholipid content were not affected by age or chronic ethanol consumption. Aged animals were able to adapt to the effects of chronic ethanol administration to the same extent as younger animals. These findings differ from studies that have examined effects of chronic ethanol consumption on behavior and neurotransmitter release among different age groups of mice. While the results are specific for liver microsomes, it appears that chronic ethanol consumption has less of an effect on liver function as compared to brain function in aged mice.