366 research outputs found
C6: Knowledge, attitude, and practice of senior dental students toward management of complications in exodontia
Introduction: Dental graduates have a professional responsibility of being competent in managing the complications in exodontia, a very commonly performed procedure. Aim: The aim of this paper was to assess the knowledge, attitude, and practice of senior dental students toward the management of complications in exodontia. Materials and Methods: Four hundred dental students participated in the study voluntarily. Verbal consent was obtained after elaborating the purpose of the study. A short validated questionnaire consisting of 12 close-ended multiple choice questions was distributed to all the students. The questionnaires were collected back and results from fully filled questionnaires were tabulated in Microsoft Excel 2007. Results: Nearly 93.4% of the students perform extractions in their practice on a routine basis. Among those 32.5% of the students have encountered complications, out of which only 20% of the students are confident in managing them. The remaining 64.8% of students who have not encountered complications are not confident in managing the same. Conclusion: This study revealed the need for increase in cases which will in turn help the students to transfer their theoretical knowledge into professional skills
Thermodynamic properties and phase equilibria for Pt-Rh alloys
The activity of rhodium in solid Pt-Rh alloys is measured in the temperature range from 900 to 1300 K using the solid-state cell Pt-Rh, Rh + Rh2O3/(Y2O3)ZrO2/Pt1-xRhx + Rh2O3, Pt-Rh The activity of platinum and the free energy, enthalpy, and entropy of mixing are derived. Activities exhibit moderate negative deviation from Raoult's law. The mixing properties can be represented by a pseudosubregular solution model in which excess entropy has the same type of functional dependence on composition as the enthalpy of mixing, ΔH = XRh (1 - XRh)[-10,970 + 45XRh] J/mol ΔSE = XRh (1- XRh)[-3.80 + 1.55 × 10-2 XRh] J/mol·K The negative enthalpy of mixing obtained in this study is in qualitative agreement with predictions of semiempirical models of Miedema and co-workers and Colinet et al. The results of this study do not support the solid-state miscibility gap suggested in the literature, but are consistent with liquidus data within experimental uncertainty limits
Electronic structure of boron and aluminum -doped layers in silicon
Recent work on atomic-precision dopant incorporation technologies has led to
the creation of both boron and aluminum -doped layers in silicon with
densities above the solid solubility limit. We use density functional theory to
predict the band structure and effective mass values of such layers,
first modeling them as ordered supercells. Structural relaxation is found to
have a significant impact on the impurity band energies and effective masses of
the boron layers, but not the aluminum layers. However, disorder in the
layers is found to lead to significant flattening of the bands in both
cases. We calculate the local density of states and doping potential for these
-doped layers, demonstrating that their influence is highly localized
with spatial extents at most 4 nm. We conclude that acceptor -doped
layers exhibit different electronic structure features dependent on both the
dopant atom and spatial ordering. This suggests prospects for controlling the
electronic properties of these layers if the local details of the incorporation
chemistry can be fine tuned.Comment: Main text 8 pages, 6 figures + Appendices 3 pages, 2 figure
Parameterizing Majorana Neutrino Couplings in the Higgs Sector
Nonzero masses for the active neutrinos - regardless of their nature or
origin - arise only after electroweak symmetry breaking. We discuss the
parameterization of neutrino couplings to a Higgs sector consisting of one
SU(2)_L scalar doublet and one SU(2)_L scalar triplet, and allow for
right-handed neutrinos whose Majorana mass parameters arise from the vacuum
expectation value of a Standard Model scalar singlet. If the neutrinos are
Majorana fermions, all Yukawa couplings can be expressed as functions of the
neutrino mass eigenvalues and a subset of the elements of the neutrino mixing
matrix. In the mass basis, the Yukawa couplings are, in general, not diagonal.
This is to be contrasted to the case of charged-fermions or Dirac neutrinos,
where couplings to the Higgs-boson are diagonal in the mass basis and
proportional only to the fermion masses. Nonetheless, all physically
distinguishable parameters can be reached if all neutrino masses are
constrained to be positive, all mixing angles constrained to lie in the first
quadrant (theta in [0,pi/2]), and all Majorana phases to lie in the first two
quadrants (phi in [0,pi]), as long as all Dirac phases vary within the entire
unit circle (delta in [0,2pi}). We discuss several concrete examples and
comment on the Casas-Ibarra parameterization for the neutrino Yukawa couplings
in the case of the type-I Seesaw Lagrangian.Comment: 13 pages, 2 eps figure
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Altered chemomechanical coupling causes impaired motility of the kinesin-4 motors KIF27 and KIF7.
Kinesin-4 motors play important roles in cell division, microtubule organization, and signaling. Understanding how motors perform their functions requires an understanding of their mechanochemical and motility properties. We demonstrate that KIF27 can influence microtubule dynamics, suggesting a conserved function in microtubule organization across the kinesin-4 family. However, kinesin-4 motors display dramatically different motility characteristics: KIF4 and KIF21 motors are fast and processive, KIF7 and its Drosophila melanogaster homologue Costal2 (Cos2) are immotile, and KIF27 is slow and processive. Neither KIF7 nor KIF27 can cooperate for fast processive transport when working in teams. The mechanistic basis of immotile KIF7 behavior arises from an inability to release adenosine diphosphate in response to microtubule binding, whereas slow processive KIF27 behavior arises from a slow adenosine triphosphatase rate and a high affinity for both adenosine triphosphate and microtubules. We suggest that evolutionarily selected sequence differences enable immotile KIF7 and Cos2 motors to function not as transporters but as microtubule-based tethers of signaling complexes
The geometric measure of entanglement for a symmetric pure state with positive amplitudes
In this paper for a class of symmetric multiparty pure states we consider a
conjecture related to the geometric measure of entanglement: 'for a symmetric
pure state, the closest product state in terms of the fidelity can be chosen as
a symmetric product state'. We show that this conjecture is true for symmetric
pure states whose amplitudes are all non-negative in a computational basis. The
more general conjecture is still open.Comment: Similar results have been obtained independently and with different
methods by T-C. Wei and S. Severini, see arXiv:0905.0012v
Effect of Transition Magnetic Moments on Collective Supernova Neutrino Oscillations
We study the effect of Majorana transition magnetic moments on the flavor
evolution of neutrinos and antineutrinos inside the core of Type-II supernova
explosions. We find non-trivial collective oscillation effects relating
neutrinos and antineutrinos of different flavors, even if one restricts the
discussion to Majorana transition electromagnetic moment values that are not
much larger than those expected from standard model interactions and nonzero
neutrino Majorana masses. This appears to be, to the best of our knowledge, the
only potentially observable phenomenon sensitive to such small values of
Majorana transition magnetic moments. We briefly comment on the effect of Dirac
transition magnetic moments and on the consequences of our results for future
observations of the flux of neutrinos of different flavors from a nearby
supernova explosion.Comment: 11 pages,appendix added, version accepted in JCA
The NMDA receptor GluN2C subunit controls cortical excitatoryinhibitory balance, neuronal oscillations and cognitive function
Despite strong evidence for NMDA receptor (NMDAR) hypofunction as an underlying factor for cognitive disorders, the precise roles of various NMDAR subtypes remains unknown. The GluN2Ccontaining NMDARs exhibit unique biophysical properties and expression pattern, and lower expression of GluN2C subunit has been reported in postmortem brains from schizophrenia patients. We found that loss of GluN2C subunit leads to a shift in cortical excitatory-inhibitory balance towards greater inhibition. Specifically, pyramidal neurons in the medial prefrontal cortex (mPFC) of GluN2C knockout mice have reduced mEPSC frequency and dendritic spine density and a contrasting higher frequency of mIPSCs. In addition a greater number of perisomatic GAD67 puncta was observed suggesting a potential increase in parvalbumin interneuron inputs. At a network level the GluN2C knockout mice were found to have a more robust increase in power of oscillations in response to NMDAR blocker MK- 801. Furthermore, GluN2C heterozygous and knockout mice exhibited abnormalities in cognition and sensorimotor gating. Our results demonstrate that loss of GluN2C subunit leads to cortical excitatoryinhibitory imbalance and abnormal neuronal oscillations associated with neurodevelopmental disorders
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