Broadband microwave burst produced by electron beams

Theoretical and experimental study of fast electron beams attracts a lot of attention in the astrophysics and laboratory. In the case of solar flares the problem of reliable beam detection and diagnostics is of exceptional importance. This paper explores the fact that the electron beams moving oblique to the magnetic field or along the field with some angular scatter around the beam propagation direction can generate microwave continuum bursts via gyrosynchrotron mechanism. The characteristics of the microwave bursts produced by beams differ from those in case of isotropic or loss-cone distributions, which suggests a new tool for quantitative diagnostics of the beams in the solar corona. To demonstrate the potentiality of this tool, we analyze here a radio burst occurred during an impulsive flare 1B/M6.7 on 10 March 2001 (AR 9368, N27W42). Based on detailed analysis of the spectral, temporal, and spatial relationships, we obtained firm evidence that the microwave continuum burst is produced by electron beams. For the first time we developed and applied a new forward fitting algorithm based on exact gyrosynchrotron formulae and employing both the total power and polarization measurements to solve the inverse problem of the beam diagnostics. We found that the burst is generated by a oblique beam in a region of reasonably strong magnetic field ($\sim 200-300$ G) and the burst is observed at a quasi-transverse viewing angle. We found that the life time of the emitting electrons in the radio source is relatively short, $\tau_l \approx 0.5$ s, consistent with a single reflection of the electrons from a magnetic mirror at the foot point with the stronger magnetic field. We discuss the implications of these findings for the electron acceleration in flares and for beam diagnostics.Comment: Astrophysical Journal, accepted: 26 pages, 8 figure

The Particle Content of Extragalactic Jets

Recent x-ray and radio data from radio sources in galaxy clusters are used to show that the pdV work required to inflate the radio lobes exceeds all other energy estimates deduced from the radio emission. If the required jet energy density has an isotropic pressure, then in almost all cases the jet cannot be confined by an external medium. This problem can be resolved with jets dominated by cold protons, but even here the accompanying energy density in relativistic electons can cause decollimation. Electron-positron jets cannot solve this problem unless they are highly beamed with unusual energy distributions. Poynting flux jets may be a viable alternative.Comment: 14 pages, 3 figures, to be published in Ap

Metabolic Tumor Imaging with Rapidly Signal-Enhanced 1-C-13-Pyruvate-d(3)

The metabolism of malignant cells differs significantly from that of healthy cells and thus, it is possible to perform metabolic imaging to reveal not only the exact location of a tumor, but also intratumoral areas of high metabolic activity. Herein, we demonstrate the feasibility of metabolic tumor imaging using signal-enhanced 1-13C-pyruvate-d3, which is rapidly enhanced via para-hydrogen, and thus, the signal is amplified by several orders of magnitudes in less than a minute. Using as a model, human melanoma xenografts injected with signal-enhanced 1-13C-pyruvate-d3, we show that the conversion of pyruvate into lactate can be monitored along with its kinetics, which could pave the way for rapidly detecting and monitoring changes in tumor metabolism

Luminescent properties of Bi-doped polycrystalline KAlCl4

We observed an intensive near-infrared luminescence in Bi-doped KAlCl4 polycrystalline material. Luminescence dependence on the excitation wavelength and temperature of the sample was studied. Our experimental results allow asserting that the luminescence peaked near 1 um belongs solely to Bi+ ion which isomorphically substitutes potassium in the crystal. It was also demonstrated that Bi+ luminescence features strongly depend on the local ion surroundings

Rapidly signal‐enhanced metabolites for atomic scale monitoring of living cells with magnetic resonance

Nuclear magnetic resonance (NMR) is widely applied from analytics to biomedicine although it is an inherently insensitive phenomenon. Overcoming sensitivity challenges is key to further broaden the applicability of NMR and, for example, improve medical diagnostics. Here, we present a rapid strategy to enhance the signals of 13C-labelled metabolites with para-hydrogen and, in particular, 13C-pyruvate, an important molecule for the energy metabolism. We succeeded to obtain an average of 27 % 13C polarization of 1-13C-pyruvate in water which allowed us to introduce two applications for studying cellular metabolism. Firstly, we demonstrate that the metabolism of 1-13C-pyruvate can serve as a biomarker in cellular models of Parkinson's disease and, secondly, we introduce the opportunity to combine real-time metabolic analysis with protein structure determination in the same cells. Based on the here presented results, we envision the use of our approach for future biomedical studies to detect diseases

Regularized energy-dependent solar flare hard x-ray spectral index

The deduction from solar flare X-ray photon spectroscopic data of the energy dependent model-independent spectral index is considered as an inverse problem. Using the well developed regularization approach we analyze the energy dependency of spectral index for a high resolution energy spectrum provided by Ramaty High Energy Solar Spectroscopic Imager (RHESSI). The regularization technique produces much smoother derivatives while avoiding additional errors typical of finite differences. It is shown that observations imply a spectral index varying significantly with energy, in a way that also varies with time as the flare progresses. The implications of these findings are discussed in the solar flare context.Comment: 13 pages; 5 figures, Solar Physics in pres

Оцінка ефективності внутрішньовенного введення лідокаїну гідрохлориду в інтраопераційному періоді

The aim of the work: to prove the fact of intravenous administration of lidocaine hydrochloride during general anesthesia to reduce the total dose of narcotic analgesics without loss of analgesic effect. Dynamic active prospective two-center study of two statistically homogeneous groups of patients was performed: in group 1 general anesthesia with fentanyl analgesia was performed, in group 2 – a combination of fentanyl and lidocaine hydrochloride. The study was performed during the anesthesiology of patients who underwent metalostesynthesis for multiple fracture with displacement of bone fragments of the upper extremity and patients undergoing laparoscopic cholecystectomy for cholelithiasis, chronic cholecystosis. It was found that the use of 1 % lidocaine hydrochloride in combination with fentanyl can significantly reduce the total dose the last one, namely the total dose of fentanyl in the group 1 was, on average, (8.63±0.72) µg/kg/h, whereas in group 2 managed to reduce the dose to (6.27±0.44) µg/kg/h to achieve adequate analgesia.Цель работы: доказать, что внутривенное введение лидокаина гидрохлорида при проведении общей анестезии позволяет уменьшить суммарную дозу наркотических анальгетиков без потери обезболивающего эффекта. Проведено динамическое активное проспективное двухцентровое исследование двух статистически однородных групп пациентов: в первой группе проводилась общая анестезия с анальгезией фентанилом, во второй – сочетание фентанила и лидокаина гидрохлорида. Исследование проводилось при анестезиологическом обеспечении больным, которым выполняли металлоостесинтез по поводу многоосколочного перелома со смещением костных отломков верхней конечности и пациентам, которым выполнялась лапароскопическая холецистэктомия по поводу желчнокаменной болезни, хронического калькулезного холецистита в стадии обострения. Было установлено, что использование 1 % лидокаина гидрохлорида в сочетании с фентанилом позволяет существенно сократить общую дозу последнего, а именно суммарная доза фентанила в первой группе составляла, в среднем (8,63 ± 0,72) мкг/кг/ч, тогда как во второй группе удалось снизить дозу до (6,27 ± 0,44) мкг/кг/ч для достижения адекватной аналгезии.Мета роботи: обґрунтувати твердження, що внутрішньовенне введення лідокаїну гідрохлориду під час проведення загальної анестезії дозволяє зменшити сумарну дозу наркотичних аналгетиків без втрати знеболювального ефекту. Проведено динамічне активне проспективне двоцентрове дослідження двох статистично однорідних груп пацієнтів: в першій групі проводилась загальна анестезія з аналгезією фентанілом, в другій – поєднання фентанілу та лідокаїну гідрохлориду. Дослідження проводилось під час анестезіологічного забезпечення хворим, яким виконували металоостеосинтез з приводу багатоуламкового перелому зі зміщенням кісткових уламків верхньої кінцівки та пацієнтам, яким виконувалась лапароскопічна холецистектомія з приводу жовчнокам’яної хвороби, хронічного калькульозного холециститу в стадії загострення. Було встановлено, що використання 1 % лідокаїну гідрохлориду в поєднанні з фентанілом дозволяє суттєво скоротити загальну дозу останнього, а саме сумарна доза фентанілу в першій групі складала, в середньому (8,63±0,72) мкг/кг/год, тоді як у другій групі вдалося зменшити дозу до 6,27±0,44 мкг/кг/год для досягнення адекватної аналгезії

Prototype ATLAS IBL Modules using the FE-I4A Front-End Readout Chip

The ATLAS Collaboration will upgrade its semiconductor pixel tracking detector with a new Insertable B-layer (IBL) between the existing pixel detector and the vacuum pipe of the Large Hadron Collider. The extreme operating conditions at this location have necessitated the development of new radiation hard pixel sensor technologies and a new front-end readout chip, called the FE-I4. Planar pixel sensors and 3D pixel sensors have been investigated to equip this new pixel layer, and prototype modules using the FE-I4A have been fabricated and characterized using 120 GeV pions at the CERN SPS and 4 GeV positrons at DESY, before and after module irradiation. Beam test results are presented, including charge collection efficiency, tracking efficiency and charge sharing.Comment: 45 pages, 30 figures, submitted to JINS