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Maxima in the thermodynamic response and correlation functions of deeply supercooled water
Kim, Kyung Hwan,Spah, Alexander,Pathak, Harshad,Perakis, Fivos,Mariedahl, Daniel,Amann-Winkel, Katrin,Sellberg, Jonas A.,Lee, Jae Hyuk,Kim, Sangsoo,Park, Jaehyun,Nam, Ki Hyun,Katayama, Tetsuo,Nilsson, American Association for the Advancement of Scienc 2017 Science Vol.358 No.6370
<P><B>Pointing to a second critical point</B></P><P>One explanation for the divergence of many of the thermodynamic properties of water is that there is a critical point in deeply supercooled water at some positive pressure. For bulk water samples, these conditions are described as “no man's land,” because ice nucleates before such temperatures can be reached. Kim <I>et al.</I> used femtosecond x-ray laser pulses to probe micrometer-sized water droplets cooled to 227 K (see the Perspective by Gallo and Stanley). The temperature dependence of the isothermal compressibility and correlation length extracted from x-ray scattering functions showed maxima at 229 K for H<SUB>2</SUB>O and 233 K for D<SUB>2</SUB>O, rather than diverging to infinity. These results point to the existence of the Widom line, a locus of maximum correlation lengths emanating from a critical point in the supercooled regime.</P><P><I>Science</I>, this issue p. 1589; see also p. 1543</P><P>Femtosecond x-ray laser pulses were used to probe micrometer-sized water droplets that were cooled down to 227 kelvin in vacuum. Isothermal compressibility and correlation length were extracted from x-ray scattering at the low–momentum transfer region. The temperature dependence of these thermodynamic response and correlation functions shows maxima at 229 kelvin for water and 233 kelvin for heavy water. In addition, we observed that the liquids undergo the fastest growth of tetrahedral structures at similar temperatures. These observations point to the existence of a Widom line, defined as the locus of maximum correlation length emanating from a critical point at positive pressures in the deeply supercooled regime. The difference in the maximum value of the isothermal compressibility between the two isotopes shows the importance of nuclear quantum effects.</P>
Measurements of Inelastic Neutron Scattering at 96 MeV from Carbon, Iron, Yttriumand Lead
A. Ohrn,C. Gustavsson,M. Blann,V. Blideanu,J. Blomgren,S. Chiba,H. Duarte,F. Haddad,C. Kalbach,J. Klug,A. Koning,C. Le brun,C. Lebrun,F. -R. Lecolley,X. Ledoux,N. Marie-noury,P. Mermod,L. Nilsson,M. O 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.23
Inelastic neutron scattering for ^(12)C, ^(56)Fe, ^(89)Y and ^(208)Pb have been measured at 96 MeV at the The Svedberg Laboratory in Uppsala and double-differential cross sections are reported. Data cover an excitation energy range of 0-45 MeV and the angular intervals are 28 - 58˚ for ^(12)C, 26 - 65˚ for ^(56)Fe and 26 - 52˚ for ^(89)Y and ^(208)Pb. In this experiment, neutron detection is based on conversion to protons in an active scintillator converter. An analysis technique in which the neutron spectra have been obtained through a folding procedure using the response of the detector system has been used. The results are compared to and are in reasonable agreement with several model predictions and with inelastic neutron scattering data at 65 MeV from University of California, Davis, USA.
PRIMARY BLACK HOLE SPIN IN OJ 287 AS DETERMINED BY THE GENERAL RELATIVITY CENTENARY FLARE
Valtonen, M. J.,Zola, S.,Ciprini, S.,Gopakumar, A.,Matsumoto, K.,Sadakane, K.,Kidger, M.,Gazeas, K.,Nilsson, K.,Berdyugin, A.,Piirola, V.,Jermak, H.,Baliyan, K. S.,Alicavus, F.,Boyd, D.,Torrent, M. Ca American Astronomical Society 2016 ASTROPHYSICAL JOURNAL LETTERS - Vol.819 No.2
<P>OJ 287 is a quasi-periodic quasar with roughly 12 year optical cycles. It displays prominent outbursts that are predictable in a binary black hole model. The model predicted a major optical outburst in 2015 December. We found that the outburst did occur within the expected time range, peaking on 2015 December 5 at magnitude 12.9 in the optical R-band. Based on Swift/XRT satellite measurements and optical polarization data, we find that it included a major thermal component. Its timing provides an accurate estimate for the spin of the primary black hole, chi = 0.313 +/- 0.01. The present outburst also confirms the established general relativistic properties of the system such as the loss of orbital energy to gravitational radiation at the 2% accuracy level, and it opens up the possibility of testing the black hole no-hair theorem with 10% accuracy during the present decade.</P>
Lunavat, Taral R.,Cheng, Lesley,Einarsdottir, Berglind O.,Olofsson Bagge, Roger,Veppil Muralidharan, Somsundar,Sharples, Robyn A.,Lasser, Cecilia,Gho, Yong Song,Hill, Andrew F.,Nilsson, Jonas A.,Lotva National Academy of Sciences 2017 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.114 No.29
<P>The BRAF inhibitors vemurafenib and dabrafenib can be used to treat patients with metastatic melanomas harboring BRAF(V600) mutations. Initial antitumoral responses are often seen, but drug-resistant clones with reactivation of the MEK-ERK pathway soon appear. Recently, the secretome of tumor-derived extracellular vesicles (EVs) has been ascribed important functions in cancers. To elucidate the possible functions of EVs in BRAF-mutant melanoma, we determined the RNA content of the EVs, including apoptotic bodies, microvesicles, and exosomes, released from such cancer cells after vemurafenib treatment. We found that vemurafenib significantly increased the total RNA and protein content of the released EVs and caused significant changes in the RNA profiles. RNA sequencing and quantitative PCR show that cells and EVs from vemurafenib-treated cell cultures and tumor tissues harvested from cell-derived and patient-derived xenografts harbor unique miRNAs, especially increased expression of miR-211-5p. Mechanistically, the expression of miR-211-5p as a result of BRAF inhibition was induced by increased expression of MITF that regulates the TRPM1 gene resulting in activation of the survival pathway. In addition, transfection of miR-211 in melanoma cells reduced the sensitivity to vemurafenib treatment, whereas miR-211-5p inhibition in a vemurafenib resistant cell line affected the proliferation negatively. Taken together, our results show that vemurafenib treatment induces miR-211-5p up-regulation in melanoma cells both in vitro and in vivo, as well as in subsets of EVs, suggesting that EVs may provide a tool to understand malignant melanoma progression.</P>
Light-Ion Production in 175 MeV Neutron-Induced Reactions on Oxygen
U. Tippawan,T. Vilaithong,S. Pomp,P. Andersson,R. Bevilacqua,J. Blomgren,C. Gustavsson,L. Nilsson,M. Osterlund,V. Simutkin,H. Sjostrand,M. Hayashi,S. Hirayama,Y. Naitou,Y. Watanabe,A. Hjalmarsson,A. P 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.23
Data on light-ion production in light nuclei such as carbon, nitrogen and oxygen are particularly important in calculations of dose distributions in human tissue for radiation therapy at neutron beams, and for dosimetry of high energy neutrons produced by high-energy cosmic radiation interacting with nuclei (nitrogen and oxygen) in the atmosphere. When studying neutron dose effects, special consideration on carbon and oxygen is needed since they are, by weight, the most abundant elements in human tissue. The MEDLEY setup at The Svedberg Laboratory (TSL), Uppsala, Sweden has been used to measure such data with double-differential cross sections (DDX) for the (n,xp), (n,xd), (n,xt), (n,^3He), and (n,α) reactions from C, O, Si, Ca, Fe, Pb, and U around 96 MeV. At the new Uppsala neutron beam facility the available energy range of quasi mono-energetic neutron beams is extended up to 175 MeV. The detector setup used in MEDLEY consists of eight so-called telescopes mounted at different angles inside an evacuated reaction chamber. Each of the telescopes consists of two fully depleted ΔE silicon surface barrier detectors (SSBD) and a CsI(Tl) crystal. In order to make measurements at this higher neutron energy possible some changes in the detector setup compared to the campaign at 96 MeV were applied Accordingly, the second ΔE detectors have been replaced by 1000 μm thick SSBDs as well as the size of the crystals used as E detectors was increased to a total length of 100 mm and a diameter of 50 mm. The ΔE - E technique is used to identify the light ions, and cutoff energies as low as 2.5 MeV for protons and 4.0 MeV for alpha particles are achieved. The data are normalised relative to elastic np scattering measured in one of the telescopes at 20 degrees. Preliminary DDXs for oxygen are presented and compared with theoretical calculations.