1-Phenyl­piperazine-1,4-diium bis­(hydrogen sulfate)

In the title compound, C10H16N2 2+·2HSO4 −, the S atoms adopt slightly distorted tetra­hedral geometry and the diprotonated piperazine ring adopts a chair conformation. In the crystal, the 1-phenyl­piperazine-1,4-diium cations are anchored between chains formed by the sulfate entities via inter­molecular bifurcated N—H⋯(O,O) and weak C—H⋯O hydrogen bonds. These hydrogen bonds contribute to the cohesion and stability of the network of the crystal structure

Dual-Band MIMO Antenna Design for 5G Smartphones Mobile Communications

In this research, an innovative L-shape slot that is fed by F-shape dual-band six-Elements multiple-input multiple-output (MIMO) antenna for mobile phones that operate in a 5G spectrum is demonstrated. This proposed antenna has six antenna elements that can operate in dual band sub-6 GHz for 5G band spectrums at 3.42-3.77 GHz and at 5.30-5.63 GHz. Every antenna element has an L-shaped slot in the ground fed by the same feedline that support the matching of the F-shaped microstrip lines. Important features of the anticipated layout are examined. It provides excellent efficiency at the operation band, appropriate isolation, adequate radiation coverage, and good S-parameters. Ant 3's provided the maximum return loss at 3.6 GHz which is-35 dB, whereas Ant 5 and Ant 6 provide the highest return losses at 5.4 GHz which is-38dB of the suggested dual-band frequency of 5G smartphones. To validate the exactness of the constructed MIMO antenna performances, the sample prototyping and experimentally measured outcomes were carried out in the Lab. Both simulated and measure result assessments revealed an extremely excellent understanding of both results. satisfactory input impedance and mutual coupling characteristics. Future smartphones can leverage the proposed design for high data-rate cellular connectivity because of these appealing properties. This is an open-access article under the CC BY 4.0 license (http://creativecommons.org/licenses/by/4.0/) Publisher : Middle Technical Universit

Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020

Instabilites mecaniques dans les cristaux liquides discotiques hexagonaux

SIGLECNRS T 58696 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Ordinary and Extraordinary Complex Refractive Indices Extraction of a Mylar Film by Transmission Spectrophotometry

A new spectrophotometric technique for the determination of both ordinary and extraordinary complex refractive indices (CRIs) of a stretched polyethylene terephthalate (Mylar) film is proposed. The sample was placed between two identical polarizers, and the transmission spectra of two different configurations (incident polarization parallel and perpendicular to the Mylar film optical axis) were recorded. Ordinary and extraordinary complex refractive indices are then extracted by fitting the experimental spectra with a theoretical model that we had elaborated in advance. A new formula for transmittance dispersion, based on the Fresnel’s coefficients formalism and using the Cauchy model, was derived to describe n and κ wavelength dependence. The suggested theoretical model succeeded in reproducing the Mylar transmission spectra across the entire visible spectral range (400, 750 nm) for both configurations, and the retrieved dispersion curves of the refractive indices, extinction coefficients, and the birefringence are comparable to results found in the literature. The proposed method is fast, straightforward, easy to set up, and cost-effective. It proved to be an excellent alternative to more conventional methods such as spectroscopic ellipsometry

Gender inequalities in diet quality and their socioeconomic patterning in a nutrition transition context in the Middle East and North Africa: a cross-sectional study in Tunisia

Abstract Background In a context of nutrition transition and major shifts in lifestyle and diet, the Middle East and North Africa features a marked gender excess adiposity gap detrimental to women. In this setting, where gender issues are especially acute, we investigated gender differences in dietary intake with a focus on diet quality, and how the differences varied with the area of residence and socio-demographic characteristics. Methods The study was conducted in 2009–2010 in the Greater Tunis region (Tunisia), as a case study of an advanced nutrition transition context in the region. A cross-sectional survey used a random, stratified, clustered sample of households: 1689 women and 930 men aged 20–49 years were analyzed. Dietary intake was assessed using a 3-day food record. Nutrient content was derived from a specific Tunisian food composition database. We analysed the Diet Quality Index-International (DQI-I) and sub-scores (variety, adequacy, moderation and balance). A score of DQI-I > 60 defined good diet quality. Inequality measures were women vs. men differences in means for interval variables and odds-ratios (OR) for DQI-I > 60. Their variation with socio-demographic characteristics was estimated using models featuring gender x covariate interactions. Results Mean energy intake/day was 2300 ± 15 kcal for women vs. 2859 ± 32 kcal for men. By 1000 g/kcal/d women consumed more fruits and sweets but less red meat and soft drinks than men. Women had a higher mean moderation sub-score than men (+ 1.8[1.4, 2.2], P  60 (45.2% vs. 55.7%, OR = 0.7[0.5, 0.8], P < 0.0001). Adjusted gender differences in DQI-I decreased with age but were higher in larger households and extreme categories of education (no-schooling and university) vs. the middle categories. Conclusion In this nutrition transition context with only average diet quality, it was somewhat lower for women. Socioeconomic patterning of gender contrasts was mild. Beyond, that women had lower adequacy and variety scores but better moderation is a possible pathway for gender specific prevention messages

Shear-enhanced diffraction from thin permanent gratings in dye-doped nematic liquid crystal cells

International audienc