151 research outputs found
Resource-efficient low-loss four-channel active demultiplexer for single photons
We report a design and implementation of a resource-efficient spatial
demultiplexer which produces 4 indistinguishable photons with efficiency of
39.7% per channel. Our scheme is based on a free-space storage/delay line which
accumulates 4 photons and releases them by a controlled polarization rotation
using a single Pockels cell.Comment: 8 pages, 7 figure
Investigation of thin films MgAl2O4, deposited on the Si substrates by vacuum thermal evaporation
The article presents data on the study of X-ray structural and microstructural characteristics of thin films of aluminum-magnesium spinel MgAl2O4 deposited on Si substrates by vacuum thermal evaporation. MgAl2O4 films have a polycrystalline rhombic structure. The values of the unit cell parameters of MgAl2O4 are calculated. Scanning electron and atomic force microscopy showed that MgAl2O4 films have a densely packed structure without cracks. Physical characteristics and good adhesion of MgAl2O4 thin films to silicon substrates indicate their possibility of using in devices of opto- and microelectronics
ПОЗДНЕГОЛОЦЕНОВОЕ ОСАДКОНАКОПЛЕНИЕ В АКТИВНЫХ ГЕОЛОГИЧЕСКИХ СТРУКТУРАХ ЧУКОТСКОГО МОРЯ
The article presents the detailed analysis results considering bottom sediments from the Chukchi Sea. Two core samples, b16 and НС–8 were taken from the northern Herald Canyon 150 km northeast from NE Wrangel Island. Core b16 has been studied in more detail. According to the 210Pb measurements, the recent sedimentation rate amounts to 0.9 mm/y–1 at the sampling point. In the bottom layer of the core sample, the minimum concentrations of biogenic components (SiO2bio, Corg, Ntot, and Br) and the increased concentrations of cold-water diatom species Thalassiosira antarctica may result from low biological productivity during the Maunder Minimum. A correlation with recent global warming (11–22 years) is shown by the increased concentrations of SiO2bio, Corg, Ntot, and Br and the decreased values of magnetic susceptibility and X-ray density in the top layer (1–2 cm) of the same core sample. The results of our geochemical and diatom analysis support the available literature data and confirm that the Late Holocene sedimentation in the Chukchi Sea takes place in the zone wherein the water transits from the Pacific to the Arctic Ocean.Представлены результаты комплексного исследования вещественного состава донных осадков, вскрытых двумя кернами в северной части каньона Геральд Чукотского моря. Одна из полученных колонок была выбрана для более детального исследования. Скорость современного осадконакопления в точке отбора этого керна, измеренная по 210Pb, составляет 0.9 мм/год. Минимальные концентрации биогенных компонентов (SiO2биог., Сорг., Nобщ., Br) и увеличение содержаний холодноводного вида диатомей Thalassiosira antarctica в нижнем слое колонки, вероятно, объясняются низкой биологической продуктивностью во время минимума Маундера. Повышенные концентрации SiO2биог, Сорг, Nобщ, Br, пониженные значения магнитной восприимчивости и рентгеновской плотности в самом верхнем интервале разреза (до 1–2 см) соответствуют последним 11–22 годам глобального потепления климата. Результаты геохимического и диатомового анализов подтверждают имеющиеся в литературе данные о том, что позднеголоценовая седиментация в Чукотском море происходит в зоне транзита тихоокеанских вод в Северный Ледовитый океан
Новый анальгетик на основе гексаазаизовюрцитана: возможность использования в онкологической практике
Purpose: to study gastrotoxic and ulcerogenic effects of a long-term administration of a newly synthesized compound from the hexaazaisowurzitan (thiowurtzine) series in rats, as well as to assess its effect on the transplantable tumor in mice.Material and Methods. Lewis lung carcinoma was transplanted into mice, and thiowurtzine was prescribed for a long course together with cyclophosphamide. In the terminal stage of tumor development the mass of the primary node, the number and area of metastases in the lungs of mice were measured. Histological sections of the stomach were studied in rats after a 90-day administration of thiowurtzine.Results. Thiowurtzine at therapeutic dosages of 50 and 100 mg/kg for a course of 19 days potentiated the effect of cyclophosphamide to inhibit tumor dissemination and exerted a direct antitumor effect in mice with lewis lung carcinoma. A dose of 1000 mg/kg for 90 days did not cause ulcerogenic action of thiowurtzine.Conclusion. The absence of a stimulating effect on tumor growth in animal experiments and intactness in relation to the gastric mucosa during chronic administration of thiowurtzine allow us to recommend this innovative analgesic for clinical study as a concomitant analgesia in cancer patients.Цель исследования - изучение гастротоксического и ульцерогенного эффектов длительного курсового введения недавно синтезированного соединение из ряда гексаазаизовюрцитана (тиовюрцин) крысам, а также оценка его влияния на перевиваемую опухоль у мышей.Материал и методы. Мышам перевивали карциному легких Льюиса, назначали тиовюрцин длительным курсом совместно с цикло-фосфаном. В терминальной стадии развития опухоли измеряли массу первичного узла, количество и площадь метастазов в легких мышей. После 90-дневного введения тиовюрцина изучали гистологические срезы желудка.Результаты. Тиовюрцин в терапевтических дозировках 50 и 100 мг/кг курсом 19 дней потенцировал действие циклофосфана в отношении торможения диссеминации опухоли и оказывал прямое противоопухолевое действие у мышей с карциномой легких Льюиса. Тиовюрцин в дозе 1000 мг/кг курсом 90 дней у крыс не вызывал ульцерогенного действия.Заключение. Отсутствие стимулирующего влияния на опухолевый рост в экспериментах на животных и интактность в отношении слизистой оболочки желудка при хроническом назначении тиовюрцина позволяют рекомендовать данный инновационный анальгетик для клинического изучения в качестве средства сопутствующей анальгезии у онкобольных на разных этапах
Intestinal Microbiota Composition of Interleukin-10 Deficient C57BL/6J Mice and Susceptibility to Helicobacter hepaticus-Induced Colitis
The mouse pathobiont Helicobacter hepaticus can induce typhlocolitis in interleukin-10-deficient mice, and H. hepaticus infection of immunodeficient mice is widely used as a model to study the role of pathogens and commensal bacteria in the pathogenesis of inflammatory bowel disease. C57BL/6J Il10[superscript −/−] mice kept under specific pathogen-free conditions in two different facilities (MHH and MIT), displayed strong differences with respect to their susceptibilities to H. hepaticus-induced intestinal pathology. Mice at MIT developed robust typhlocolitis after infection with H. hepaticus, while mice at MHH developed no significant pathology after infection with the same H. hepaticus strain. We hypothesized that the intestinal microbiota might be responsible for these differences and therefore performed high resolution analysis of the intestinal microbiota composition in uninfected mice from the two facilities by deep sequencing of partial 16S rRNA amplicons. The microbiota composition differed markedly between mice from both facilities. Significant differences were also detected between two groups of MHH mice born in different years. Of the 119 operational taxonomic units (OTUs) that occurred in at least half the cecum or colon samples of at least one mouse group, 24 were only found in MIT mice, and another 13 OTUs could only be found in MHH samples. While most of the MHH-specific OTUs could only be identified to class or family level, the MIT-specific set contained OTUs identified to genus or species level, including the opportunistic pathogen, Bilophila wadsworthia. The susceptibility to H. hepaticus-induced colitis differed considerably between Il10[superscript −/−] mice originating from the two institutions. This was associated with significant differences in microbiota composition, highlighting the importance of characterizing the intestinal microbiome when studying murine models of IBD.National Institutes of Health (U.S.) (Grant NIH P01-CA26731)National Institutes of Health (U.S.) (Grant NIH P30ES0026731)National Institutes of Health (U.S.) (Grant NIH R01-OD011141
Superconducting spintronics
The interaction between superconducting and spin-polarized orders has recently emerged as a major research field following a series
of fundamental breakthroughs in charge transport in superconductor-ferromagnet heterodevices which promise new device
functionality. Traditional studies which combine spintronics and superconductivity have mainly focused on the injection of
spin-polarized quasiparticles into superconducting materials. However, a complete synergy between superconducting and magnetic
orders turns out to be possible through the creation of spin-triplet Cooper pairs which are generated at carefully engineered
superconductor interfaces with ferromagnetic materials. Currently, there is intense activity focused on identifying materials
combinations which merge superconductivity and spintronics in order to enhance device functionality and performance. The results
look promising: it has been shown, for example, that superconducting order can greatly enhance central effects in spintronics such as
spin injection and magnetoresistance. Here, we review the experimental and theoretical advances in this field and provide an outlook
for upcoming challenges related to the new concept of superconducting spintronics.J.L. was supported by the Research Council of Norway, Grants No. 205591 and 216700.
J.W.A.R. was supported by the UK Royal Society and the Leverhulme Trust through an
International Network Grant (IN-2013-033).This is the accepted manuscript. The final version is available at http://www.nature.com/nphys/journal/v11/n4/full/nphys3242.html
ДИНАМИКА IN VITRO ДЕГРАДАЦИИ НЕТКАНЫХ МАТРИКСОВ ИЗ ПОЛИМОЛОЧНОЙ КИСЛОТЫ В МОДЕЛЬНОЙ БИОЛОГИЧЕСКОЙ ЖИДКОСТИ
The weekly in vitro degradation of fibrous-porous non-woven polylactide scaffolds made by aerodynamic formation in a turbulent gas flow has been studied with 37 °С in model RPMI-1640 medium imitated body fluid of organism. Lactate monomers released into solution exponentially and reached slowly a maximum value the end of the observation (5th week of dissolution). At the same time, reducing the concentrations of calcium and inorganic phosphorus ions in solutions contacted with tested samples (10×10×1 mm2) testified about chemical elements adsorption on artificial material. Ions exchange with biological fluids may be a basis of regulated bioactivity of fibrous-porous non-woven biodegradable material in application to intercellular matrix bioengineering for regenerative medicineИзучена понедельная деградация in vitro при температуре 37 °С волокнисто-пористых нетканых скеффолдов из полимолочной кислоты, полученных аэродинамическим формированием в турбулентном газовом потоке, в модельной среде RPMI-1640, имитирующей телесную жидкость организма. Мономеры молочной кислоты выделялись в раствор по экспоненциальному закону и медленно достигали максимальных концентраций к концу наблюдений (5-я нед растворения). В то же время снижение концентраций ионов кальция и неорганического фосфора в растворах, контактирующих с тестируемыми образцами (10 ´ 10 ´ 1 мм2 ), свидетельствовало об адсорбции химических элементов на искусственном материале. Обмен ионами с биологическими жидкостями могут быть основой регулируемой биоактивности волокнисто-пористого биодеградируемого материала в приложении к биоинженерии межклеточного матрикса для регенеративной медицины
Higher levels of glutamate in the associative-striatum of subjects with prodromal symptoms of schizophrenia and patients with first-episode psychosis
The glutamatergic and dopaminergic systems are thought to be involved in the pathophysiology of schizophrenia. Their interaction has been widely documented and may have a role in the neurobiological basis of the disease. The aim of this study was to compare, using proton magnetic resonance spectroscopy (1H-MRS), glutamate levels in the precommissural dorsal-caudate (a dopamine-rich region) and the cerebellar cortex (negligible for dopamine) in the following: (1) 18 antipsychotic-naïve subjects with prodromal symptoms and considered to be at ultra high-risk for schizophrenia (UHR), (2) 18 antipsychotic-naïve first- episode psychosis patients (FEP), and (3) 40 age- and sex- matched healthy controls. All subjects underwent a 1H-MRS study using a 3Tesla scanner. Glutamate levels were quantified and corrected for the proportion of cerebrospinal fluid and percentage of gray matter in the voxel. The UHR and FEP groups showed higher levels of glutamate than controls, without differences between UHR and FEP. In the cerebellum, no differences were seen between the three groups. The higher glutamate level in the precommissural dorsal-caudate and not in the cerebellum of UHR and FEP suggests that a high glutamate level (a) precedes the onset of schizophrenia, and (b) is present in a dopamine-rich region previously implicated in the pathophysiology of schizophrenia.peer-reviewe
Effect of the Polarization of Isolated Three-Spin Groups on the Free Induction Decay and Solid Echo of Nuclear Magnetic Resonance
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