A Search for EUV Emission from Comets with the Cosmic Hot Interstellar Plasma Spectrometer (CHIPS)

We have obtained EUV spectra between 90 and 255 \AA of the cometsC/2002 T7 (LINEAR), C/2001 Q4 (NEAT), and C/2004 Q2 (Machholz) near their perihelion passages in 2004 with the Cosmic Hot Interstellar Plasma Spectrometer (CHIPS). We obtained contemporaneous data on Comet NEAT Q4 with the $Chandra$ X-ray Observatory ACIS instrument, marking the first simultaneous EUV and X-ray spectral observations of a comet. The total CHIPS/EUV observing times were 337 ks for Q4, 234 ks for T7, and 483 ks for Machholz and for both CHIPS and $Chandra$ we calculate we have captured all the comet flux in the instrument field of view. We set upper limits on solar wind charge exchange emission lines of O, C, N, Ne and Fe occurring in the spectral bandpass of CHIPS. The spectrum of Q4 obtained with $Chandra$ can be reproduced by modeling emission lines of C, N O, Mg, Fe, Si, S, and Ne solar wind ions. The measured X-ray emission line intensities are consistent with our predictions from a solar wind charge exchange model. The model predictions for the EUV emission line intensities are determined from the intensity ratios of the cascading X-ray and EUV photons arising in the charge exchange processes. They are compatible with the measured limits on the intensities of the EUV lines. For comet Q4, we measured a total X-ray flux of 3.7$\times 10^{-12}$ ergs cm$^{-2}$ s$^{-1}$, and derive from model predictions a total EUV flux of 1.5$\times 10^{-12}$ erg cm$^{-2}$ s$^{-1}$. The CHIPS observations occurred predominantly while the satellite was on the dayside of Earth. For much of the observing time, CHIPS performed observations at smaller solar angles than it was designed for and EUV emission from the Sun scattered into the instrument limited the sensitivity of the EUV measurements.Comment: 28 pages total, 4 tables, 7 figures. Accepted by The Astrophysical Journa

Дослідження параметрів ліофілізації при одержанні ліпосомальної форми іринотекану

The creation of the liposomal irinotecan is one of the main ways to reduce toxicity and increase the effectiveness of chemotherapy. Lyophilization makes it possible to obtain a product with a guaranteed stability of the size and encapsulation efficiency.Aim. To optimize the content of the cryoprotector in the liposomal irinotecan, and develop lyophilization parameters to produce liposomes with the maximum encapsulation of irinotecan in them, alongside while maintaining the nanosize.Materials and methods. Egg phosphatidylcholine from Lipoid (Germany) was used for preparation of liposomes. Lyophilization was carried out in a Quarco device (PR China). The encapsulation degree was determined on a Shimadzu LC-20 instrument (Japan) by HPLC method developed earlier.Results and discussion. The optimal content of the cryoprotector – trehalose dihydrate has been studied. It has been found that the optimal content of trehalose dihydrate is 8 % (w/w). The modes of the product lyophilization have been studied. The secondary drying temperature in the range of 10-20 °C has been determined. At the secondary drying temperature of 10 °C the residual moisture content was 5-8 %, which was beyond the target range. At 20 °C the water content in the lyophilizate was 0.5-0.8 %, the loss of encapsulation was up to 20 %. The mode of drying at 15 °C was optimal, while the residual water content in the lyophilizate was 1.5-2.8 %, the loss of encapsulation was 13 %, the size of the liposomes after lyophilization and rehydration did not change significantly compared to the initial one.Conclusions. As a result of the studies, liposomes with irinotecan have been obtained. The content of trehalose dihydrate as a cryoprotector in the range of 4-10 % has been studied. It has been shown that the optimum content of trehalose dihydrate is 8 % (w/w); moreover, the encapsulation decrease in lyophilization is 13 %. The modes of the liposomal irinotecan lyophilization have been studied at the final drying temperature of 10, 15 and 20 °C. It has been found that the optimum final drying temperature is 15 °C.Создание липосомальной формы иринотекана – один из основных путей уменьшения токсичности и повышения эффективности при проведении химиотерапии. Лиофилизация позволяет получать продукт с гарантированным сохранением размеров и параметров инкапсуляции, поэтому исследование параметров данного процесса является актуальным.Целью исследования являются оптимизация содержания криопротектора в липосомальной форме иринотекана, разработка процесса лиофилизации для получения ЛС с максимальной инкапсуляцией в них иринотекана при сохранении наноразмеров.Материалы и методы. Для изготовления ЛС использовали яичный фосфатидилхолин фирмы Lipoid, лиофилизацию проводили в аппарате Quarco производства КНР. Определение степени инкапсуляции проводили методом ВЭЖХ на приборе Shimadzu LC-20.Результаты и их обсуждение. Проведено исследование содержания криопротектора – трегалозы дигидрата. Установлено, что оптимальным является содержание трегалозы дигидрата 8 % (масс). Проведено изучение режимов лиофилизации продукта. Изучена температура вторичного высушивания от 10 до 20 °С. При температуре вторичной сушки 10 °С содержание остаточной влаги составляло 5-8 %, что выходило за целевые рамки. При 20 °С содержание воды в лиофилизате составляло 0,5-0,8 %, потеря инкапсуляции – до 20 %. Оптимальным являлся режим при досушивании при 15 °С, при этом содержание остаточной воды в лиофилизате составило 1,5-2,8 %, потеря инкапсуляции составила 13 %, размер липосом после лиофилизации и регидратации существенно не изменялся в сравнении с исходным.Выводы. В результате проведенных исследований получены лекарственные средства с иринотеканом. Исследовано содержание трегалозы дигидрата в качестве криопротектора в диапазоне от 4 до 10 %. Показано, что оптимальным является содержание трегалозы дигидрата 8 % (мас), при этом снижение инкапсуляции при лиофилизации составляет 13 %. Исследованы режимы лиофилизации ЛС с иринотеканом при температуре досушивания 10, 15, 20 °С. Установлено, что оптимальной является температура досушивания 15 °С.Створення ліпосомальной форми іринотекану – один з основних шляхів зменшення токсичності і підвищення ефективності при проведенні хіміотерапії. Ліофілізація дозволяє отримувати продукт з гарантованим збереженням розмірів і параметрів інкапсуляції, тому дослідження параметрів даного процесу є актуальним. Метою дослідження є оптимізація вмісту кріопротектора в ліпосомальній формі іринотекану, розробка процесу ліофілізаціі для отримання ЛЗ з максимальною інкапсуляцією в них іринотекану при збереженні нанорозмірів. Матеріали та методи. Для виготовлення лікарського засобу використовували яєчний фосфатидилхолін фірми Lipoid, ліофілізацію проводили в апараті Quarco виробництва КНР. Визначення ступеня інкапсуляції проводили методом ВЕРХ на приладі Shimadzu LC-20.Результати та їх обговорення. Проведено дослідження вмісту кріопротектора – трегалози дигідрату. Встановлено, що оптимальним є вміст трегалози дигідрату 8 % (мас). Проведено вивчення режимів ліофілізації продукту. Вивчено температуру вторинного висушування від 10 до 20 °С. При температурі вторинного висушування 10 °С вміст залишкової вологи становив 5-8 %, що виходило за цільові рамки. При 20 °С вміст води в ліофілізаті становив 0,5- 0,8 %, втрата інкапсуляції – до 20 %. Оптимальним був режим при досушуванні при 15 °С, при цьому вміст залишкової води в ліофілізаті склав 1,5-2,8 %, втрата інкапсуляції склала 13 %, розмір ліпосом після ліофілізації та регідратації істотно не змінювався в порівнянні з вихідним значенням.Висновки. В результаті проведених досліджень отримані лікарські засоби з іринотеканом. Досліджено вміст трегалози дигідрату як кріопротектора в діапазоні від 4 до 10 %. Показано, що оптимальним є вміст трегалози дигідрату 8 % (мас), при цьому зниження інкапсуляції при ліофілізації становить 13 %. Досліджені режими ліофілізації лікарських засобів з іринотеканом при температурі досушування 10, 15, 20 °С. Встановлено, що оптимальною є температура досушування 15 °С

ТЕХНОЛОГІЧНІ ПАРАМЕТРИ ВИРОБНИЦТВА ЛІПОСОМ З ОКСАЛІПЛАТИНОМ

The development of medicines of a nanoscale diapason opens a new trend in the modern pharmaceutical industry. Reducing the toxicity of known cytotoxic agents is one of the advantages of the liposomal biotechnology platform. The aim of the work is to offer scientifically grounded technology of production of liposomal form of oxaliplatin based on the experiment. To analyze intermediate products, define control points.Materials and Methods. Egg phosphatidylcholine produced byLipoid,Germany was used to make liposomes. Dipalmitoylphosphatidylglycerin, cholesterol, solvents used by the companySigma-Aldrich,USA. The lipid film was obtained on a rotary evaporator Buchi 210. For homogenization, an extrusion method at high pressure was used. The lyophilization process was carried out on Quarco equipment (PRC).Results and Discussion. The experimental industrial technology of obtaining the liposomal form of oxaliplatin was developed. The development of a full-fledged technology requires the study of colloidal properties of a heterogeneous nano-system, especially at the rehydration stage, lyophilization parameters, validation of control methods for the encapsulation of oxaliplatin into liposomes, validation of quantitative determination and determination of impurities.Conclusions. A new, original technology and control points for obtaining liposomal form of oxaliplatin are proposed. The technology has been tested on batches of preparations, used for preclinical studies.Мета роботи: на основі експерименту запропонувати науково-обґрунтовану технологію виробництва ліпосомальної форми оксаліплатину. Провести аналіз проміжних продуктів, визначити контрольні точки.Матеріали і методи. Для виготовлення ліпосом використовували яєчний фосфатидилхолін виробництва Lipoid (Німеччина). Дипальмітоілфосфатидилгліцерин, холестерин і розчинники використовували виробництва фірми Sigma-Aldrich (США). Ліпідну плівку отримували на роторному випарювачі Buchi 210. Для гомогенізації використовували метод екструзії при високому тиску. Процес ліофілізації здійснювали на обладнанні Quarco (КНР).Результати й обговорення.  Розроблено дослідно-промислову технологію отримання ліпосомальної форми оксаліплатину. Створення повноцінної технології вимагало вивчення колоїдних властивостей гетерогенної лікарської наносистеми, особливо на етапі регідратації, параметрів ліофілізації, валідації методик контролю ступеня інкапсуляції оксаліплатину в ліпосоми, валідації кількісного визначення і визначення сторонніх домішок.Висновки. Запропоновано нову, оригінальну технологію отримання ліпосомальної форми оксаліплатину. Технологію апробовано на серіях препарату для проведення доклінічних досліджень

On the structure and stability of magnetic tower jets

Modern theoretical models of astrophysical jets combine accretion, rotation, and magnetic fields to launch and collimate supersonic flows from a central source. Near the source, magnetic field strengths must be large enough to collimate the jet requiring that the Poynting flux exceeds the kinetic-energy flux. The extent to which the Poynting flux dominates kinetic energy flux at large distances from the engine distinguishes two classes of models. In magneto-centrifugal launch (MCL) models, magnetic fields dominate only at scales $\lesssim 100$ engine radii, after which the jets become hydrodynamically dominated (HD). By contrast, in Poynting flux dominated (PFD) magnetic tower models, the field dominates even out to much larger scales. To compare the large distance propagation differences of these two paradigms, we perform 3-D ideal MHD AMR simulations of both HD and PFD stellar jets formed via the same energy flux. We also compare how thermal energy losses and rotation of the jet base affects the stability in these jets. For the conditions described, we show that PFD and HD exhibit observationally distinguishable features: PFD jets are lighter, slower, and less stable than HD jets. Unlike HD jets, PFD jets develop current-driven instabilities that are exacerbated as cooling and rotation increase, resulting in jets that are clumpier than those in the HD limit. Our PFD jet simulations also resemble the magnetic towers that have been recently created in laboratory astrophysical jet experiments.Comment: 16 pages, 11 figures, published in ApJ: ApJ, 757, 6

Non-thermal escape of molecular hydrogen from Mars

We present a detailed theoretical analysis of a non-thermal escape of molecular hydrogen from Mars induced by collisions with hot atomic oxygen from martian corona. To accurately describe the energy transfer in O + H$_2(v,j)$ collisions, we performed extensive quantum-mechanical calculations of state-to-state elastic, inelastic, and reactive cross sections. The escape flux of H$_2$ molecules was evaluated using a simplified 1D column model of the martian atmosphere with realistic densities of atmospheric gases and hot oxygen production rates for the low solar activity conditions. An average density of the non-thermal escape flux of H$_2$ of $1.9\times10^5$ cm$^{-2}$s$^{-1}$ was obtained considering energetic O atoms produced in dissociative recombinations of O$_{2}^{+}$ ions. Predicted rovibrational distribution of the escaping H$_2$ was found to contain a significant fraction of higher rotational states. While the non-thermal escape rate was found to be lower than Jeans flux for H$_2$ molecules, the non-thermal escape rates of HD and D$_2$ are significantly higher than their respective Jeans rates. The accurate values of non-thermal escape fluxes of different molecular isotopes of H$_2$ may be important in analyses of evolution of the martian atmosphere. The described molecular ejection mechanism is general and expected to contribute to atmospheric escape of H$_2$ and other light molecules from planets, satellites, and exoplanetary bodies.Comment: submitted to Geophys. Res. Let

Structural trace of adaptation in motive nuclei of spinal cord of rats in hypokinesia and after physical loading in the recovery period

The purpose of this paper is to study the morphological changes of neurocytes in spinal cord of rats in hypokinesia and subsequent physical loading. Studies were performed on 55 laboratory rats of Wistar line. Materials of the research were the anterior horns of the gray matter of L5-S2 spinal segments. Preparations stained by Nissl and Viktorov were examined histologically. Hypokinesia was modeled following on the author’s technique. It was established that during prolonged hypokinesia in neurocytes of spinal cord of rats morphological changes in cell size and shape of the motor nuclei of all segments under study have been recorded. The number of hypochromic, hyperchromic destructively unchanged and hyperchromic destructively altered neurocytes increase; shadow cells appears, as well as cases of satellitosis and neuronophagia. Decrease in of albumen synthetical neurocyte function has been recorded. Physical loading of the average aerobic capacity leads to normalization of structural and functional state of neurocytes and enhances the reparative processes, as evidenced by a number of positive changes in morphometric parameters: increase in the number of normochromic neurocytes and decreasing the number of hyper- and hypochromic neurocytes with destructive signs, absence of pyknotic forms. Morphological parameters of neurocytes and their nuclei after physical loading of average aerobic capacity do not differ from those in the control group of intact animals. In neurocytes of this group of rats RNA concentration increases by 12.6% compared to animals after prolonged hypokinesia. Neurocytes of spinal cord of rats after prolonged hypokinesia develop significant morphological changes which are characterized by emergence of a significant number of hyperchromic neurocytes with signs of destructive changes and shadow cells, as well as and hypochromic neurocytes with signs of destructive changes, reduction in size and change of shape of perikaryons of neurocytes and their nuclei. Morphological changes of neurocytes after prolonged hypokinesia are accompanied by violations of biosynthetic processes, as evidenced by RNA decrease in the cytoplasm of efferent neurocytes of spinal cord of rats. Physical loading of average aerobic capacity leads to normalization of structural and functional state of neurocytes and promotes the reparative processes suported by positive changes in morphometric parameters

The Nucleon-Nucleon Interaction in a Chiral Constituent Quark Model

We study the short-range nucleon-nucleon interaction in a chiral constituent quark model by diagonalizing a Hamiltonian comprising a linear confinement and a Goldstone boson exchange interaction between quarks. The six-quark harmonic oscillator basis contains up to two excitation quanta. We show that the highly dominant configuration is $\mid s^4p^2[42]_O [51]_{FS}>$ due to its specific flavour-spin symmetry. Using the Born-Oppenheimer approximation we find a strong effective repulsion at zero separation between nucleons in both $^3S_1$ and $^1S_0$ channels. The symmetry structure of the highly dominant configuration implies the existence of a node in the S-wave relative motion wave function at short distances. The amplitude of the oscillation of the wave function at short range will be however strongly suppressed. We discuss the mechanism leading to the effective short-range repulsion within the chiral constituent quark model as compared to that related with the one-gluon exchange interaction.Comment: 31 pages, LaTe

Moscow-type NN-potentials and three-nucleon bound states

A detailed description of Moscow-type (M-type) potential models for the NN interaction is given. The microscopic foundation of these models, which appear as a consequence of the composite quark structure of nucleons, is discussed. M-type models are shown to arise naturally in a coupled channel approach when compound or bag-like six-quark states, strongly coupled to the NN channel, are eliminated from the complete multiquark wave function. The role of the deep-lying bound states that appear in these models is elucidated. By introducing additional conditions of orthogonality to these compound six-quark states, a continuous series of almost on-shell equivalent nonlocal interaction models, characterized by a strong reduction or full absence of a local repulsive core (M-type models), is generated. The predictions of these interaction models for 3N systems are analyzed in detail. It is shown that M-type models give, under certain conditions, a stronger binding of the 3N system than the original phase-equivalent model with nodeless wave functions. An analysis of the 3N system with the new versions of the Moscow NN potential describing also the higher even partial waves is presented. Large deviations from conventional NN force models are found for the momentum distribution in the high momentum region. In particular, the Coulomb displacement energy for nuclei ^3He - ^3H displays a promising agreement with experiment when the ^3H binding energy is extrapolated to the experimental value.Comment: 23 pages Latex, 9 figures, to appear in Phys.Rev.

The Atmospheric Chemistry Suite (ACS) of Three Spectrometers for the ExoMars 2016 Trace Gas Orbiter

The Atmospheric Chemistry Suite (ACS) package is an element of the Russian contribution to the ESA-Roscosmos ExoMars 2016 Trace Gas Orbiter (TGO) mission. ACS consists of three separate infrared spectrometers, sharing common mechanical, electrical, and thermal interfaces. This ensemble of spectrometers has been designed and developed in response to the Trace Gas Orbiter mission objectives that specifically address the requirement of high sensitivity instruments to enable the unambiguous detection of trace gases of potential geophysical or biological interest. For this reason, ACS embarks a set of instruments achieving simultaneously very high accuracy (ppt level), very high resolving power (>10,000) and large spectral coverage (0.7 to 17 μm—the visible to thermal infrared range). The near-infrared (NIR) channel is a versatile spectrometer covering the 0.7–1.6 μm spectral range with a resolving power of ∼20,000. NIR employs the combination of an echelle grating with an AOTF (Acousto-Optical Tunable Filter) as diffraction order selector. This channel will be mainly operated in solar occultation and nadir, and can also perform limb observations. The scientific goals of NIR are the measurements of water vapor, aerosols, and dayside or night side airglows. The mid-infrared (MIR) channel is a cross-dispersion echelle instrument dedicated to solar occultation measurements in the 2.2–4.4 μm range. MIR achieves a resolving power of >50,000. It has been designed to accomplish the most sensitive measurements ever of the trace gases present in the Martian atmosphere. The thermal-infrared channel (TIRVIM) is a 2-inch double pendulum Fourier-transform spectrometer encompassing the spectral range of 1.7–17 μm with apodized resolution varying from 0.2 to 1.3 cm−1. TIRVIM is primarily dedicated to profiling temperature from the surface up to ∼60 km and to monitor aerosol abundance in nadir. TIRVIM also has a limb and solar occultation capability. The technical concept of the instrument, its accommodation on the spacecraft, the optical designs as well as some of the calibrations, and the expected performances for its three channels are described

Substellar companions and isolated planetary mass objects from protostellar disc fragmentation

Self-gravitating protostellar discs are unstable to fragmentation if the gas can cool on a time scale that is short compared to the orbital period. We use a combination of hydrodynamic simulations and N-body orbit integrations to study the long term evolution of a fragmenting disc with an initial mass ratio to the star of M_disc/M_star = 0.1. For a disc which is initially unstable across a range of radii, a combination of collapse and subsequent accretion yields substellar objects with a spectrum of masses extending (for a Solar mass star) up to ~0.01 M_sun. Subsequent gravitational evolution ejects most of the lower mass objects within a few million years, leaving a small number of very massive planets or brown dwarfs in eccentric orbits at moderately small radii. Based on these results, systems such as HD 168443 -- in which the companions are close to or beyond the deuterium burning limit -- appear to be the best candidates to have formed via gravitational instability. If massive substellar companions originate from disc fragmentation, while lower-mass planetary companions originate from core accretion, the metallicity distribution of stars which host massive substellar companions at radii of ~1 au should differ from that of stars with lower mass planetary companions.Comment: 5 pages, accepted for publication in MNRA