632 research outputs found
Anomalous double peak structure in Nb/Ni superconductor/ferromagnet tunneling DOS
We have experimentally investigated the density of states (DOS) in Nb/Ni
(S/F) bilayers as a function of Ni thickness, . Our thinnest samples show
the usual DOS peak at , whereas intermediate-thickness samples
have an anomalous ``double-peak'' structure. For thicker samples ( nm), we see an ``inverted'' DOS which has previously only been reported in
superconductor/weak-ferromagnet structures. We analyze the data using the
self-consistent non-linear Usadel equation and find that we are able to
quantitatively fit the features at if we include a large amount
of spin-orbit scattering in the model. Interestingly, we are unable to
reproduce the sub-gap structure through the addition of any parameter(s).
Therefore, the observed anomalous sub-gap structure represents new physics
beyond that contained in the present Usadel theory.Comment: 4 pages, 3 figure
Isolation, production, purification, assay and characterization of fibrinolytic enzymes (Nattokinase, Streptokinase and Urokinase) from bacterial sources
Nattokinase, Streptokinase and Urokinase are novel fibrinolytic enzymes which are isolated from Bacillus subtilis, ÎČ-haemolytic Streptococci and urine sample. The fibrinolytic enzyme Nattokinase, Streptokinase and Urokinase was purified from supernatant of Bacillus subtilis, ÎČ-haemolytic Streptococci and recombinant E.coli containing short fragment genomic DNA of Pseudomonas sp. Culture broth and showed thermophilic, hydrophilic, and strong fibrinolytic activity. The optimum temperature and pH of Nattokinase, Streptokinase and Urokinase were 37-55°C and 9, 27-37°C and 7 and 55°C and 9, respectively. The molecular weight of Nattokinase, Streptokinase and Urokinase was approximately 28 kDa, 47 kDa and 34 kDa, respectively, as determined by sodium dodecyl sulfatepolyacrylamide gel electrophoresis. The caseinolytic activity of Nattokinase, Streptokinase and Urokinase were 576.73 U, 467.73 U and 785.73 U, respectively, while fibrinolytic activity achieved by fibrin plate method were 10 U, 5 U and 15 U, respectively.Key words: Anticoagulant activity, submerge fermentation, fibrinolytic enzyme activity, protein fraction precipitation, casein, serum and plasminogen plate technique, enzyme thermodynamics, haemolytic activity, enzyme screening, expression system, zymography, Edman degradation
Optimizing global health experiences in emergency medicine residency programs: A consensus statement from the Council of Emergency Medicine Residency Directors 2011 Academic Assembly global health specialty track
BACKGROUND: An increasing number of emergency medicine (EM) residency training programs have residents interested in participating in clinical rotations in other countries. However, the policies that each individual training program applies to this process are different. To our knowledge, little has been done in the standardization of these experiences to help EM residency programs with the evaluation, administration and implementation of a successful global health clinical elective experience. The objective of this project was to assess the current status of EM global health electives at residency training programs and to establish recommendations from educators in EM on the best methodology to implement successful global health electives. METHODS: During the 2011 Council of Emergency Medicine Residency Directors (CORD) Academic Assembly, participants met to address this issue in a mediated discussion session and working group. Session participants examined data previously obtained via the CORD online listserve, discussed best practices in global health applications, evaluations and partnerships, and explored possible solutions to some of the challenges. In addition a survey was sent to CORD members prior to the 2011 Academic Assembly to evaluate the resources and processes for EM residentsâ global experiences. RESULTS: Recommendations included creating a global health working group within the organization, optimizing a clearinghouse of elective opportunities for residents and standardizing elective application materials, site evaluations and resident assessment/feedback methods. The survey showed that 71.4% of respondents have global health partnerships and electives. However, only 36.7% of programs require pre-departure training, and only 20% have formal competency requirements for these global health electives. CONCLUSIONS: A large number of EM training programs have global health experiences available, but these electives and the trainees may benefit from additional institutional support and formalized structure
High carrier mobility in transparent Ba1-xLaxSnO3 crystals with a wide band gap
We discovered that perovskite (Ba,La)SnO3 can have excellent carrier mobility
even though its band gap is large. The Hall mobility of Ba0.98La0.02SnO3
crystals with the n-type carrier concentration of \sim 8-10\times10 19 cm-3 is
found to be \sim 103 cm2 V-1s-1 at room temperature, and the precise
measurement of the band gap \Delta of a BaSnO3 crystal shows \Delta=4.05 eV,
which is significantly larger than those of other transparent conductive
oxides. The high mobility with a wide band gap indicates that (Ba,La)SnO3 is a
promising candidate for transparent conductor applications and also epitaxial
all-perovskite multilayer devices
X-ray diffraction measurements of the c-axis Debye-Waller factors of YBa2Cu3O7 and HgBa2CaCu2O6
We report the first application of x-rays to the measurement of the
temperature dependent Bragg peak intensities to obtain Debye-Waller factors on
high-temperature superconductors. Intensities of (0,0,l) peaks of YBa2Cu3O7 and
HgBa2CaCu2O6 thin films are measured to obtain the c-axis Debye-Waller factors.
While lattice constant and some Debye-Waller factor measurements on high Tc
superconductors show anomalies at the transition temperature, our measurements
by x-ray diffraction show a smooth transition of the c-axis Debye-Waller
factors through T. This suggests that the dynamic displacements of the
heavy elements along the c-axis direction in these compounds do not have
anomalies at Tc. This method in combination with measurements by other
techniques will give more details concerning dynamics of the lattice.Comment: 4 pages, 2 figures. To be published in Physical Review B (Brief
Report
Origin of the Thermoreversible fcc-bcc Transition in Block Copolymer Solutions
The thermoreversible fcc-bcc transition in concentrated block copolymer micellar solutions is shown to be driven by decreases in the aggregation number as the solvent penetrates the core, leading to a softer intermicelle potential. Small-angle neutron scattering measurements in a dilute solution are used to quantify the temperature-dependent micellar characteristics. The observed phase boundary is in excellent agreement with recent simulations of highly branched star polymers.This work was supported primarily by the MRSEC
Program of the National Science Foundation under Grant
No. DMR-0212302, and also in part by the Brain Korea
21 Program endorsed by the Korean Ministry of
Education. We acknowledge helpful discussions with
C. N. Likos
Stellar Lyman-alpha Emission Lines in the Hubble Space Telescope Archive: Intrinsic Line Fluxes and Absorption from the Heliosphere and Astrospheres
We search the Hubble Space Telescope (HST) archive for previously unanalyzed
observations of stellar H I Lyman-alpha emission lines, our primary purpose
being to look for new detections of Lyman-alpha absorption from the outer
heliosphere, and to also search for analogous absorption from the astrospheres
surrounding the observed stars. The astrospheric absorption is of particular
interest because it can be used to study solar-like stellar winds that are
otherwise undetectable. We find and analyze 33 HST Lyman-alpha spectra in the
archive. All the spectra were taken with the E140M grating of the Space
Telescope Imaging Spectrograph (STIS) instrument on board HST. The HST/STIS
spectra yield 4 new detections of heliospheric absorption (70 Oph, Xi Boo, 61
Vir, and HD 165185) and 7 new detections of astrospheric absorption (EV Lac, 70
Oph, Xi Boo, 61 Vir, Delta Eri, HD 128987, and DK UMa), doubling the previous
number of heliospheric and astrospheric detections. When combined with previous
results, 10 of 17 lines of sight within 10 pc yield detections of astrospheric
absorption. This high detection fraction implies that most of the ISM within 10
pc must be at least partially neutral, since the presence of H I within the ISM
surrounding the observed star is necessary for an astrospheric detection. In
contrast, the detection percentage is only 9.7% (3 out of 31) for stars beyond
10 pc. Our Lyman-alpha analyses provide measurements of ISM H I and D I column
densities for all 33 lines of sight, and we discuss some implications of these
results. Finally, we measure chromospheric Lyman-alpha fluxes from the observed
stars. We use these fluxes to determine how Lyman-alpha flux correlates with
coronal X-ray and chromospheric Mg II emission, and we also study how
Lyman-alpha emission depends on stellar rotation.Comment: 56 pages, 15 figures; AASTEX v5.0 plus EPSF extensions in mkfig.sty;
accepted by ApJ
Preservation of Ovarian Function after Hematopoietic Cell Transplantation (HCT): More Possible Than We Thought?
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