GaAs hetero-epitaxial layers grown by MOVPE on exactly-oriented and off-cut (1 1 1)Si: Lattice tilt, mosaicity and defects content

Integration of III-V devices with Si-photonics and fabrication of monolithic III-V/Si tandem solar cells require the heteroepitaxy of III-V compounds on Si. We report on the lattice tilt, mosaicity and defects content of relaxed GaAs grown by MOVPE on exactly-oriented and 4°-offcut (1 1 1)Si. Thin GaAs single-layers grown at 400 °C and annealed at 700 °C show ∼ 3×10^8 cm−2 density of surface pinholes. Double-layer samples were obtained by GaAs overgrowth at 700 °C. GaAs epilayers are tilted by (0.05–0.14)° with respect to Si. Rotational twins were observed in X-ray diffraction (XRD) pole figures: the most abundant ones originate from 60°-rotation of GaAs around the [1 ̄1 ̄1 ̄] growth direction and are identified as micro-twins along the GaAs/Si hetero-interface. Twins obtained by rotations around the [1 ̄1 ̄1], [11 ̄1 ̄], and [1 ̄11 ̄] directions or by combined rotations around the growth direction and one of the former, were also observed. The GaAs mosaicity and block size were studied through high-resolution XRD intensity mapping: for single-layer samples crystal blocks are ascribed to 3–5 nm thin micro-twins, whose size does not change upon annealing. In double-layer samples thicker (32–35 nm) micro-twins occur. GaAs samples grown on offcut (1 1 1)Si show less rotational twins but a reduced mosaic block size with respect to exactly-oriented Si

A 10-3 drift velocity monitoring chamber

The MEG-II experiment searches for the lepton flavor violating decay: mu in electron and gamma. The reconstruction of the positron trajectory uses a cylindrical drift chamber operated with a mixture of He and iC4H10 gas. It is important to provide a stable performance of the detector in terms of its electron transport parameters, avalanche multiplication, composition and purity of the gas mixture. In order to have a continuous monitoring of the quality of gas, we plan to install a small drift chamber, with a simple geometry that allows to measure very precisely the electron drift velocity in a prompt way. This monitoring chamber will be supplied with gas coming from the inlet and the outlet of the detector to determine if gas contaminations originate inside the main chamber or in the gas supply system. The chamber is a small box with cathode walls, that define a highly uniform electric field inside two adjacent drift cells. Along the axis separating the two drift cells, four staggered sense wires alternated with five guard wires collect the drifting electrons. The trigger is provided by two 90Sr weak calibration radioactive sources placed on top of a two thin scintillator tiles telescope. The whole system is designed to give a prompt response (within a minute) about drift velocity variations at the 0.001 level

Molecular testing in the diagnosis of differentiated thyroid carcinomas

Different genetic mutations and other molecular alterations in papillary thyroid cancer (PTC) and follicular thyroid cancer (FTC) can be detected in fine-needle aspiration (FNA) of thyroid nodules, and can be used successfully to ameliorate cancer diagnosis and management of patients with thyroid nodules. The greatest experience has been obtained with the diagnostic use of BRAF mutation that is strongly specific for malignancy when detected using well-validated techniques. The strongest diagnostic result can be obtained testing FNA samples for a panel of mutations that typically involve TERT, BRAF, PAX8/PPARγ, RAS, and RET/PTC. Finding any of these mutations in a thyroid nodule provides strong indication for malignancy and helps to refine clinical management for a significant proportion of patients with indeterminate cytology. The use of molecular markers, as TERT, BRAF, PAX8/PPARγ, RAS, and RET/PTC, may be considered for patients with indeterminate FNA cytology (FNAC) to help guide management. In patients with indeterminate TIR3 FNA, the combination of precise molecular marker expression analysis with molecular mutations evaluations could ameliorate significantly the accuracy of cancer diagnosis. However other prospective studies are needed to identify more accurate molecular markers. Finally, the knowledge of these molecular pathways has permitted the development of new targeted therapies for aggressive TC

Upper and lower airway inflammation in severe asthmatics: a guide for a precision biologic treatment

Background and aims: Severe asthma may require the prescription of one of the biologic drugs currently available, using surrogate markers of airway inflammation (serum IgE levels and allergic sensitization for anti-IgE, or blood eosinophils for anti-IL5/IL5R). Our objective: to assess upper and lower airway inflammation in severe asthmatics divided according to the eligibility criteria for one of the target biologic treatments. Methods: We selected 91 severe asthmatics, uncontrolled despite high-dose ICS-LABA, and followed for >6 months with optimization of asthma treatment. Patients underwent clinical, functional and biological assessment, including induced sputum and nasal cytology. They were then clustered according to the eligibility criteria for omalizumab or mepolizumab/benralizumab. Results: Four clusters were selected: A (eligible for omalizumab, n = 23), AB (both omalizumab and mepolizumab, n = 26), B (mepolizumab, n = 22) and C (non-eligible for both omalizumab and mepolizumab, n = 20). There was no difference among clusters for asthma control (Asthma Control Test and Asthma Control Questionnaire 7), pre-bronchodilator forced expiratory volume in 1 s, serum IgE and fractional exhaled nitric oxide levels. Sputum eosinophils were numerically higher in clusters AB and B, in agreement with the higher levels of blood eosinophils. Allergic rhinitis was more frequent in clusters A and AB, while chronic rhinosinusitis with nasal polyps prevalence increased progressively from A to C. Eosinophils in nasal cytology were higher in clusters AB, B and C. Conclusion: Eosinophilic upper and lower airway inflammation is present in the large majority of severe asthmatics, independently from the prescription criteria for the currently available biologics, and might suggest the use of anti-IL5/IL5R or anti IL4/13 also in patients without blood eosinophilia. The reviews of this paper are available via the supplemental material section

Serum gamma-glutamyltransferase fractions in Myotonic Dystrophy type I: Differences with healthy subjects and patients with liver disease.

Objectives: Elevation of serum gamma-glutamyltransferase (GGT), in absence of a clinically significant liver damage, is often found in Myotonic Dystrophy type-1 (DM1). In this study we investigated if a specific GGT fraction pattern is present in DM1. Designs and methods: We compared total and fractional GGT values (b-, m-, s-, f-GGT) among patients with DM1 or liver disease (LD) and healthy subjects (HS). Results: The increase of GGT in DM1 and LD, vs HS, was mainly due to s-GGT (median: 32.7; 66.7; and 7.9 U/L, respectively), and b-GGT (8.5; 18.9; and 2.1 U/L). The subset of DM1 patients matched with HS with corresponding serum GGT showed higher b-GGT (6.0 vs 4.2 U/L). Conclusions: DM1 patients with normal total GGT values showed an alteration of the production and release in the blood of GGT fractions. Since increased s-GGT is also found in LD, a sub-clinical liver damage likely occurs in DM1 subjects apparently free of liver disease

Glucose tolerance is negatively associated with circulating progenitor cell levels

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Italian Association of Sleep Medicine (AIMS) position statement and guideline on the treatment of menopausal sleep disorders

Insomnia, vasomotor symptoms (VMS) and depression often co-occur after the menopause, with consequent health problems and reductions in quality of life. The aim of this position statement is to provide evidence-based advice on the management of postmenopausal sleep disorders derived from a systematic review of the literature. The latter yielded results on VMS, insomnia, circadian rhythm disorders, obstructive sleep apnea (OSA) and restless leg syndrome (RLS). Overall, the studies show that menopausal hormone therapy (MHT) improves VMS, insomnia, and mood. Several antidepressants can improve insomnia, either on their own or in association with MHT; these include selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Long-term benefits for postmenopausal insomnia may also be achieved with non-drug strategies such as cognitive behavioral therapy (CBT) and aerobic exercise. Continuous positive airway pressure (CPAP) and mandibular advancement devices (MADs) both reduce blood pressure and cortisol levels in postmenopausal women suffering from OSA. However, the data regarding MHT on postmenopausal restless legs syndrome are conflicting

MEG Upgrade Proposal

We propose the continuation of the MEG experiment to search for the charged lepton flavour violating decay (cLFV) \mu \to e \gamma, based on an upgrade of the experiment, which aims for a sensitivity enhancement of one order of magnitude compared to the final MEG result, down to the $6 \times 10^{-14}$ level. The key features of this new MEG upgrade are an increased rate capability of all detectors to enable running at the intensity frontier and improved energy, angular and timing resolutions, for both the positron and photon arms of the detector. On the positron-side a new low-mass, single volume, high granularity tracker is envisaged, in combination with a new highly segmented, fast timing counter array, to track positron from a thinner stopping target. The photon-arm, with the largest liquid xenon (LXe) detector in the world, totalling 900 l, will also be improved by increasing the granularity at the incident face, by replacing the current photomultiplier tubes (PMTs) with a larger number of smaller photosensors and optimizing the photosensor layout also on the lateral faces. A new DAQ scheme involving the implementation of a new combined readout board capable of integrating the diverse functions of digitization, trigger capability and splitter functionality into one condensed unit, is also under development. We describe here the status of the MEG experiment, the scientific merits of the upgrade and the experimental methods we plan to use.Comment: A. M. Baldini and T. Mori Spokespersons. Research proposal submitted to the Paul Scherrer Institute Research Committee for Particle Physics at the Ring Cyclotron. 131 Page

Impact of concomitant thyroid pathology on preoperative workup for primary hyperparathyroidism

BACKGROUND: The former standard surgical treatment in patients with primary hyperparathyroidism (pHPT) has been bilateral cervical exploration. New localization techniques and the possibility of intraoperative measurement of intact parathormone (iPTH) permit a focused, minimally invasive parathyroidectomy (MIP). The introduction of MIP without complete neck exploration leads to the potential risk of missing thyroid pathology. The aim of the present study is to evaluate the value of MIP in respect to coexisting thyroid findings and their impact on preoperative workup for primary hyperparathyroidism. METHODS: This is a prospective study including 30 consecutive patients with pHPT (median age 65 years; 17 females, 13 males). In all patients preoperative localization was performed by ultrasonography and 99m Tc-MIBI scintigraphy- Intraoperative iPTH monitoring was routinely done. RESULTS: Ten patients (33%) had a concurrent thyroid finding requiring additional thyroid surgery, and two patients (7%) with negative localization results underwent bilateral neck exploration. Therefore, MIP was attempted in 18 (60%) patients. The conversion rate to a four gland exploration was 6% (1/18). The sensitivities of 99m Tc-MIBI scanning and ultrasonography were 83.3% and 76.6%, respectively. The respective accuracy rates were 83.3% and 76.6%. Of note, the combination of the two modalities did not improve the sensitivity and accuracy in our patient population. During a median follow-up of 40 months, none of the patients developed persistent or recurrent hypocalcaemia, resulting in a 100% cure rate. CONCLUSION: Coexisting thyroid pathology is relatively frequent in patients with pHPT in our region. Among patients having pHPT without any thyroid pathology, the adenoma localization is correct with either ultrasonography or 99m Tc-MIBI scintigraphy in the majority of cases. MIP with iPTH monitoring are highly successful in this group of patients and this operative technique should be the method of choice

Commissioning of the PADME experiment with a positron beam

The PADME experiment is designed to search for a hypothetical dark photon A' produced in positron-electron annihilation using a bunched positron beam at the Beam Test Facility of the INFN Laboratori Nazionali di Frascati. The expected sensitivity to the A'-photon mixing parameter ϵ is 10-3, for A' mass ≤ 23.5 MeV/c 2 after collecting ∼1013 positrons-on-target. This paper presents the PADME detector status after commissioning in July 2019. In addition, the software algorithms employed to reconstruct physics objects, such as photons and charged particles, and the calibration procedures adopted are illustrated in detail. The results show that the experimental apparatus reaches the design performance, and is able to identify and measure standard electromagnetic processes, such as positron bremsstrahlung and electron-positron annihilation into two photons