KIC7668647: a 14 day beaming sdB+WD binary with a pulsating subdwarf

The recently discovered subdwarf B (sdB) pulsator KIC7668647 is one of the 18 pulsating sdB stars detected in the Kepler field. It features a rich g-mode frequency spectrum, with a few low-amplitude p-modes at short periods. We use new ground-based low-resolution spectroscopy, and the near-continuous 2.88 year Kepler lightcurve, to reveal that KIC7668647 consists of a subdwarf B star with an unseen white-dwarf companion with an orbital period of 14.2d. An orbit with a radial-velocity amplitude of 39km/s is consistently determined from the spectra, from the orbital Doppler beaming seen by Kepler at 163ppm, and from measuring the orbital light-travel delay of 27 by timing of the many pulsations seen in the Kepler lightcurve. The white dwarf has a minimum mass of 0.40 M_sun. We use our high signal-to-noise average spectra to study the atmospheric parameters of the sdB star, and find that nitrogen and iron have abundances close to solar values, while helium, carbon, oxygen and silicon are underabundant relative to the solar mixture. We use the full Kepler Q06--Q17 lightcurve to extract 132 significant pulsation frequencies. Period-spacing relations and multiplet splittings allow us to identify the modal degree L for the majority of the modes. Using the g-mode multiplet splittings we constrain the internal rotation period at the base of the envelope to 46-48d as a first seismic result for this star. The few p-mode splittings may point at a slightly longer rotation period further out in the envelope of the star. From mode-visibility considerations we derive that the inclination of the rotation axis of the sdB in KIC7668647 must be around ~60 degrees. Furthermore, we find strong evidence for a few multiplets indicative of degree 3 <= L <= 8, which is another novelty in sdB-star observations made possible by Kepler.Comment: arXiv admin note: text overlap with arXiv:1206.387

Bulk Viscosity driven clusterization of quark-gluon plasma and early freeze-out in relativistic heavy-ion collisions

We introduce a new scenario for heavy ion collisions that could solve the lingering problems associated with the so-called HBT puzzle. We postulate that the system starts expansion as the perfect quark-gluon fluid but close to freeze-out it splits into clusters, due to a sharp rise of bulk viscosity in the vicinity of the hadronization transition. We then argue that the characteristic cluster size is determined by the viscosity coefficient and the expansion rate. Typically it is much smaller and independent of the total system volume. These clusters maintain the pre-existing outward-going flow, as a spray of droplets, but develop no flow of their own, and hadronize by evaporation. We provide an ansatz for converting the hydrodynamic output into clusters.Comment: Accepted for publication, Phys. Rev. C. Arguments considerably expanded, refined and reworde

Evaluating oxygen tensions related to bone marrow and matrix for msc differentiation in 2d and 3d biomimetic lamellar scaffolds

The physiological O microenvironment of mesenchymal stem cells (MSCs) and osteoblasts and the dimensionality of a substrate are known to be important in regulating cell phenotype and function. By providing the physiologically normoxic environments of bone marrow (5%) and matrix (12%), we assessed their potential to maintain stemness, induce osteogenic differentiation, and enhance the material properties in the micropatterned collagen/silk fibroin scaffolds that were produced in 2D or 3D. Expression of osterix (OSX) and vascular endothelial growth factor A (VEGFA) was significantly enhanced in the 3D scaffold in all oxygen environments. At 21% O , OSX and VEGFA expressions in the 3D scaffold were respectively 13,200 and 270 times higher than those of the 2D scaffold. Markers for assessing stemness were significantly more pronounced on tissue culture polystyrene and 2D scaffold incubated at 5% O . At 21% O , we measured significant increases in ultimate tensile strength (p < 0.0001) and Young’s modulus (p = 0.003) of the 3D scaffold compared to the 2D scaffold, whilst 5% O hindered the positive effect of cell seeding on tensile strength. In conclusion, we demonstrated that the 3D culture of MSCs in collagen/silk fibroin scaffolds provided biomimetic cues for bone progenitor cells toward differentiation and enhanced the tensile mechanical properties. 2 2 2 2

Unilateral Spinal Anaesthesia in Calves

ΔΕΝ ΔΙΑΤΙΘΕΤΑΙ ΕΡΙΛΗΨΗIn this study, we aimed to evaluate the effects of unilateral anaesthesia by the administration of hyperbaric bupivacaine through the lumbosacral space into the subarachnoid space in calves. A total of 10 calves with unilateral femoral fractures were included in the study. After each calf was placed in a lateral position on the side intended for surgery, 15 mg of hyperbaric bupivacaine was slowly injected into the subarachnoid space. The onset, duration and depth of anaesthesia were determined by the pinprick test (scale 1–4). In addition, heart rate, diastolic arterial blood pressure, systolic arterial blood pressure, mean arterial blood pressure, respiratory rate and body temperature of the calves were monitored and recorded from the onset to 120 min after anaesthesia. The onset of unilateral spinal anaesthesia was within 20 s and the mean duration of anaesthesia was 155.40 min. Although there were statistical differences between hemodynamic values in the study, they were within the reference values. As a result, we believe that unilateral spinal anaesthesia in calves provides adequate anaesthesia for use in orthopaedic procedures; thus, it can be used in practice

Cross-resistance to cytosine arabinoside in human acute myeloid leukemia cells selected for resistance to vincristine

Aim: The goals of the study were to reveal the involvement of P-glycoprotein (P-gp), the product of multidrug resistance 1 gene (MDR1) in cellular resistance to vincristine (VCR) and investigate cross-resistance against cytosine arabinoside (Ara-C) in HL60 and HL60/VCR cell lines. Methods: HL60 cells (human acute myeloid leukemia cell line) were cultured on medium with 1–50 nM of VCR for 4–6 weeks, and VCR resistant cells (HL60/VCR) were selected. The viability of cells was assessed by MTT assay and the expression of MDR1 gene was detected by RT-PCR. Results: No expression of MDR1 gene was revealed in HL60 cells, but MDR1 started to be expressed after incubation of cells with 2 nM of VCR and its expression level elevates with increase of agent concentration. MTT test has shown that HL-60/VCR cells were 75-fold more resistant to VCR and 42-fold higher resistant to cytosine arabinoside (Ara-C) compared to sensitive HL60 cells. Conclusion: Aquired resistance to VCR and cross-resistance to Ara-C correlates with MDR1 gene expression in vitro.Целью работы было исследование участия Р-гликопротеина (Р-gp), продукта гена-1 множе­ственной лекарственной устойчивости (MDR1) в устойчивости клеток лейкемии человека к винкристину (ВКР) и перекрестной резистентности к цитозинарабинозиду (Аrа-C). Методы: клетки острой миелоидной лейкемии линии HL60 культивировали в среде с 1–50 и ВКР в течение 4–6 нед, после чего были отселектированы ВКР-резистентные клетки (HL60/ВКР). Влияние препаратов на жизнеспособность клеток изучали при помощи МТТ-метода, экспресию гена MDR — методом полимеразной цепной реакции обратной транскрипции. Результаты: в клетках линии HL60 экспрессия гена MDR не была выявлена, но была зарегистрирована после инкубации клеток с 2 нM ВКР, причем ее уровень возрастал по мере повышения концентрации ВКР в среде инкубации. Показано, что устойчивость клеток линии HL-60/ВКР к ВКР и Аrа-C в 75 и в 42 раза выше, соотвественно, чем таковая клеток линии HL60. Выводы: приобретенная устойчивость к ВКР и перекрестная устойчивость к Аrа-C коррелирует с уровнем экспрессии гена MDR

NMR relaxation rate in the field-induced octupolar liquid phase of spin-1/2 J1-J2 frustrated chains

In the spin-1/2 frustrated chain with nearest-neighbor ferromagnetic exchange J1 and next-nearest-neighbor antiferromagnetic exchange J2 under magnetic field, magnetic multipolar-liquid (quadrupolar, octupolar, and hexadecapolar) phases are widely expanded from the saturation down to a low-field regime. Recently, we have clarified characteristic temperature and field dependence of the NMR relaxation rate 1/T_1 in the quadrupolar phase. In this paper, we examine those of 1/T_1 in the octupolar phase combining field theoretical method with numerical data. The relevance of the results to quasi one-dimensional J1-J2 magnets such as PbCuSO4(OH)2, Rb2Cu2Mo3O12 and Li2ZrCuO4 is shortly discussed.Comment: 6 pages (1 column), 3 figure