Synthesis, crystal structure and spectroscopic studies of a new silver complex derived from [1-(3-pyridinyl) ethanone]

In this work, a new silver (I) complex, [Ag(3-pye)2(H2O)](NO3) where 3-pye=1-(3-pyridinyl) ethanone, has been synthesized and characterized by elemental analyses, FT-IR, fluorescence spectroscopy, and single X-ray crystallography. The X-ray diffraction analysis revealed that the Ag(I) complex crystallized in the monoclinic system with the C2/c space group. Computational studies were performed using DFT approache on the present complex to get insight into the structural parameters, spectral characteristics and electronic properties. The characterization results were found to be consistent with the proposed structure of the complex, and the DFT approach supported the experimental results. Also, Hirshfeld surface analysis was used to identify the non-covalent interactions within the crystal structure as well as to visualize the conformity of the crystal structure

Our experience on brachial plexus blockade in upper extremity surgery

Objective: Peripheral nerve blocks are usually used either alone or along with general anesthesia for postoperative analgesia. We also aimed to present the results and experiences.Materials and methods: This retrospective study was conducted to scan the files of patients who underwent orthopedic upper extremity surgery with peripheral nerve block between September 2009 and October 2010. After ethics committee approval was obtained, 114 patients who were ASA physical status I-III, aged 18-70, performed upper extremity surgery in the Orthopedics and Traumatology Clinic were included to study. Patients’ demographic data, clinical diagnoses, premedication status, peripheral block type, local anesthetic dose, stimuplex needle types, hemodynamic parameters at the during surgery, the first postoperative analgesic requirements, complications and patient satisfaction were recorded.Results: Demographic data were similar to each other. Brachial plexus block was commonly performed for the forearm surgery. Infraclavicular block was performed the most frequently to patients. As the classical methods in the supine position were preferred in 98.2% of patients, Stimuplex A needle (B. Braun, Melsungen AG, Germany) have been used for blockage in 80.7% of patients. Also, in 54.4% of patients, 30 ml of local anesthetic solution composed of bupivacaine + prilocaine was used for blockade. Blocks applied to patients had provided adequate anesthesia.Conclusion: Since the brachial plexus blockade guided peripheral nerve stimulator for upper extremity surgery provide adequate depth of anesthesia and analgesia, it may be a good alternative to general anesthesia because of unwanted side effect

Seismic Constraints on Helium Abundances from the TESS Southern CVZ

Poster for Cool Stars 21 Stellar helium abundances strongly determine their structure and evolution. However, since helium cannot be detected directly in the photospheres of cool stars, helium abundances are one of the most poorly-constrained inputs to stellar models. It is therefore typical to assume a relationship with the initial abundances of other heavy elements, typically of linear form described by a gradient ΔY/ΔZ. Attempts to determine from globular-cluster stellar populations and Galactic H-II regions have so far not yielded any consensus about empirically reasonable values of ΔY/ΔZ, or, for that matter, even whether such a linear relation is observationally justifiable. Separately, asteroseismology permits the inference of stellar helium abundances, either directly through acoustic-glitch measurements, or indirectly through the forward modelling of stellar oscillation mode frequencies. Using constraints on the initial helium abundance derived from ensemble asteroseismology and stellar forward modelling against individual mode frequencies of a collection of field stars in the TESS, Kepler, and K2 fields, we characterise the helium-metallicity relation of the brightest cool stars in the solar neighbourhood. We find a large spread of seismic initial helium abundances for any given metallicity, rather than a single well-defined linear enrichment law

TESS asteroseismology of the known red-giant host stars HD 212771 and HD 203949

International audienc

TESS Asteroseismology of α\alpha Mensae: Benchmark Ages for a G7 Dwarf and its M-dwarf Companion

Asteroseismology of bright stars has become increasingly important as a method to determine fundamental properties (in particular ages) of stars. The Kepler Space Telescope initiated a revolution by detecting oscillations in more than 500 main-sequence and subgiant stars. However, most Kepler stars are faint, and therefore have limited constraints from independent methods such as long-baseline interferometry. Here, we present the discovery of solar-like oscillations in $\alpha$ Men A, a naked-eye (V=5.1) G7 dwarf in TESS's Southern Continuous Viewing Zone. Using a combination of astrometry, spectroscopy, and asteroseismology, we precisely characterize the solar analog alpha Men A (Teff = 5569 +/- 62 K, R = 0.960 +/- 0.016 Rsun, M = 0.964 +/- 0.045 Msun). To characterize the fully convective M dwarf companion, we derive empirical relations to estimate mass, radius, and temperature given the absolute Gaia magnitude and metallicity, yielding M = 0.169 +/- 0.006, R = 0.19 +/- 0.01 and Teff = 3054 +/- 44 K. Our asteroseismic age of 6.2 +/- 1.4 (stat) +/- 0.6 (sys) Gyr for the primary places $\alpha$ Men B within a small population of M dwarfs with precisely measured ages. We combined multiple ground-based spectroscopy surveys to reveal an activity cycle of 13.1 +/- 1.1 years, a period similar to that observed in the Sun. We used different gyrochronology models with the asteroseismic age to estimate a rotation period of ~30 days for the primary. Alpha Men A is now the closest (d=10pc) solar analog with a precise asteroseismic age from space-based photometry, making it a prime target for next-generation direct imaging missions searching for true Earth analogs.Comment: Accepted to The Astrophysical Journal; 15 pages, 10 figure

Characteristics of food allergy in children: National multicenter study

Conference: Congress of the European-Academy-of-Allergy-and-Clinical-Immunology (EAACI) Location: Lisbon, PORTUGAL Date: JUN 01-05, 2019Background : Food allergies impose a significant burden on the life of the child and the family. In this study, to determine the demographic characteristics of food allergies, we investigated the characteristics of patients with food allergies in different regions of Pediatric Allergy- Immunology departments in Turkey. Method : Turkey ' s National Study of Allergy and Clinical Immunology Society has conducted a Study Group on Food Allergies. 25 centers participated in this multicenter, cross- sectional and descriptive study.European Academy of Allergy and Clinical Immunolog

Age dating of an early Milky Way merger via asteroseismology of the naked-eye star ν Indi

Over the course of its history, the Milky Way has ingested multiple smaller satellite galaxies1. Although these accreted stellar populations can be forensically identified as kinematically distinct structures within the Galaxy, it is difficult in general to date precisely the age at which any one merger occurred. Recent results have revealed a population of stars that were accreted via the collision of a dwarf galaxy, called Gaia–Enceladus1, leading to substantial pollution of the chemical and dynamical properties of the Milky Way. Here we identify the very bright, naked-eye star ν Indi as an indicator of the age of the early in situ population of the Galaxy. We combine asteroseismic, spectroscopic, astrometric and kinematic observations to show that this metal-poor, alpha-element-rich star was an indigenous member of the halo, and we measure its age to be 11.0±0.7 (stat) ±0.8 (sys) billion years. The star bears hallmarks consistent with having been kinematically heated by the Gaia–Enceladus collision. Its age implies that the earliest the merger could have begun was 11.6 and 13.2 billion years ago, at 68% and 95% confidence, respectively. Computations based on hierarchical cosmological models slightly reduce the above limits

Detection and Characterization of Oscillating Red Giants: First Results from the TESS Satellite

Since the onset of the "space revolution" of high-precision high-cadence photometry, asteroseismology has been demonstrated as a powerful tool for informing Galactic archeology investigations. The launch of the NASA Transiting Exoplanet Survey Satellite (TESS) mission has enabled seismic-based inferences to go full sky—providing a clear advantage for large ensemble studies of the different Milky Way components. Here we demonstrate its potential for investigating the Galaxy by carrying out the first asteroseismic ensemble study of red giant stars observed by TESS. We use a sample of 25 stars for which we measure their global asteroseimic observables and estimate their fundamental stellar properties, such as radius, mass, and age. Significant improvements are seen in the uncertainties of our estimates when combining seismic observables from TESS with astrometric measurements from the Gaia mission compared to when the seismology and astrometry are applied separately. Specifically, when combined we show that stellar radii can be determined to a precision of a few percent, masses to 5%-10%, and ages to the 20% level. This is comparable to the precision typically obtained using end-of-mission Kepler data

Yıldız İç Yapı Modellerinin Asterosismik Olarak İncelenmesi

Yıldızların yapı ve evrimin anlamak için genel olarak iç yapı modellerine başvurulmaktadır. Yıldızları en iyi temsil eden modeller gözlem parametreleriyle birlikte belirlenmektedir. Bunun için elde edilen modellerin çıktı verileri gözlem verileriyle kıyaslanmaktadır. Bir yıldız modeller yardımıyla merkezinden yüzeyin kadar temsil edilebilmektedir. Yıldızlardan alınan fotonlar sayesinde gözlem ile modellerin yüzey parametreleri kıyaslanabilir. Ancak yıldızların model merkezi koşullarının gözlemlerle kıyaslanması oldukça zordur. Günümüzde ise gelişen teknoloji ve uzay teleskopları sayesinde artık yıldızların merkez ve merkezi bölgeleri hakkında gözlemsel verilere sahip olunabilmektedir. Bualanda en önemli gelişmeler yıldız sismolojisi (asterosismoloji) sayesinde olmuştur. Asterosismolojiyle iç yapı modelleri daha detaylı olarak incelenebilir ve yıldızlara ait temel parametreler doğrudan gözlemsel veriler kullanılarak daha kolay ve hassas olarak belirlenebilir. Bu çalışmada güneş kompozisyonunda olan 1.00-1.60 M¤ kütle aralığındaki iç yapı modelleri incelendi. MESA evrim koduyla elde edilen bu modellerin asterosismik olan ve asterosismik olmayan parametreleri birbiriyle kıyaslandı. Bu sayede yıldızların tespit edilmesi zor olan yaşa dair ilişkiler elde edildi. Modellerden elde edilen 2??/R3 ile yaş arasında bir lineer ilişki ilk kez bu çalışmada bulundu