1,229 research outputs found
Comparison of relapse rates of depot and oral antipsychotics in patients with schizophrenia
Introduction: Antipsychotics are the mainstay of treatment in schizophrenia. First-generation and second-generation antipsychotics are available as oral and depot formulations. The aim of this study was to compare the relapse rate in patients with schizophrenia treated with depot and oral antipsychotics. Methods: All patients diagnosed with schizophrenia under the Top End Mental Health Service in Darwin, Australia during a period of five years were included. Their medications and history of relapses were retrieved from electronic records. Mean relapses-per-month was calculated and compared using the independent t-test and ANOVA. Results and discussion: The study sample contained 193 patients; 137 were males. The mean relapses-per-month for oral formulations was significantly higher than for depot formulations. Second-generation antipsychotic depot formulations had significantly reduced mean relapses-permonth compared to oral second-generation formulations. The mean relapses-per-month for firstgeneration antipsychotics depot was not significantly different from first-generation depot formulations. First-generation antipsychotics depot formulations were significantly more effective than oral second-generation. Zuclopenthixol appeared to be the best first-generation antipsychotics depot compared to flupenazine and flupenthixol. First-generation antipsychotics depot formulations were equally effective as Second-generation antipsychotics depot formulations. Conclusion: Depot formulations overcome some of the adherence problems with oral therapy, and the resultant continuous therapy is effective in reducing relapse rates
Synthesis and characterization of some novel coumarin based various 2-aryl-pyrido [3,2-c] coumarins
A survey of the literature reveals that the number of coumarin derivatives having heterocyclic moieties either as substituent groups or fused with parent coumarin nucleus possesses a variety of functions and are widely used in drugs and dyes. Because of this wide utility, the synthesis of coumarin has remained a subject of active interest. Looking at the importance of these heterocoumarins and with a view to exploring new methods of their synthesis, the present work was undertaken and this synthesis deals with various 2-aryl-pyrido [3,2-c] coumarins. The compounds have been synthesized by reacting Mannich bases of various 4-hydroxy coumarins with pyridinium salts of various aroyl methyl bromides in the presence of ammonium acetate and acetic acid. All the compounds synthesized have been characterized by analytical and spectral data.
Keywords: Pyrido, Coumarins, Krohanke’s reaction
Performance Evaluation of Vanilla, Residual, and Dense 2D U-Net Architectures for Skull Stripping of Augmented 3D T1-weighted MRI Head Scans
Skull Stripping is a requisite preliminary step in most diagnostic
neuroimaging applications. Manual Skull Stripping methods define the gold
standard for the domain but are time-consuming and challenging to integrate
into processing pipelines with a high number of data samples. Automated methods
are an active area of research for head MRI segmentation, especially deep
learning methods such as U-Net architecture implementations. This study
compares Vanilla, Residual, and Dense 2D U-Net architectures for Skull
Stripping. The Dense 2D U-Net architecture outperforms the Vanilla and Residual
counterparts by achieving an accuracy of 99.75% on a test dataset. It is
observed that dense interconnections in a U-Net encourage feature reuse across
layers of the architecture and allow for shallower models with the strengths of
a deeper network.Comment: Research Article submitted to the 2nd International Conference on
Biomedical Engineering Science and Technology: Roadway from Laboratory to
Market, at the National Institute of Technology Raipur, Chhattisgarh, Indi
Turbulence generation by a shock wave interacting with a random density inhomogeneity field
When a planar shock wave interacts with a random pattern of pre-shock density
non-uniformities, it generates an anisotropic turbulent velocity/vorticity
field. This turbulence plays an important role at the early stages of the
mixing process in the compressed fluid. This situation emerges naturally in
shock interaction with weakly inhomogeneous deuterium-wicked foam targets in
Inertial Confinement Fusion (ICF) and with density clumps/clouds in
astrophysics. We present an exact small-amplitude linear theory describing such
interaction. It is based on the exact theory of time and space evolution of the
perturbed quantities behind a corrugated shock front for a single-mode
pre-shock non-uniformity. Appropriate mode averaging in 2D results in closed
analytical expressions for the turbulent kinetic energy, degree of anisotropy
of velocity and vorticity fields in the shocked fluid, shock amplification of
the density non-uniformity, and sonic energy flux radiated downstream. These
explicit formulas are further simplified in the important asymptotic limits of
weak/strong shocks and highly compressible fluids. A comparison with the
related problem of a shock interacting with a pre-shock isotropic vorticity
field is also presented.Comment: This article corresponds to a presentation given at the Second
International Conference and Advanced School "Turbulent Mixing and Beyond,"
held on 27 July - 07 August 2009 at the Abdus Salam International Centre for
Theoretical Physics, Trieste, Italy. That Conference Proceeding will be
published as a Topical Issue of the Physica Scripta IOP scienc
Synthesis of furano[2,3-c] /pyrrolo[2,3-c]coumarins and synthesis of 1(H)-[1]benzopyrano[3,4-b][1]benzopyrano[3’,4’-d] furan-7(H)-ones /1(H)-[1]benzopyrano[3,4-b][1]benzopyrano [3’,4’-d]pyrrole-7(H)-ones
A series of synthesis of various 1-aryl-furano[2,3-c] and 1-phenyl-2-methyl-furano [2,3-c]coumarins;1-aryl-pyrrolo[2,3-c]and1-phenyl-2methylpyrrolo[2,3c]coumarins; 1aryl1H1] benzopyrano[3,4,-b][1]benzpyrano [3’,4’-d]furan-7H-ones and 1-aryl-1(H)-[1]benzopyrano[3,4,-b][1]benzpyrano[3’,4’-d]pyrrole-7(H)-ones. 1-Aryl-furano [2,3-c]coumarins and 1-phenyl-2-methyl-furano[2,3-c]coumarin have been synthesized by reacting 3-hydroxy coumarin with various 2-aryl-1-nitro-ethenes and 1-phenyl-2-nitro-propene respectively in the presence of piperidine and methanol as solvent. 1-Aryl-pyrrolo [2,3-c]coumarins and 1-phenyl-2-methyl-pyrrolo[2,3-c] coumarin also have been synthesised by reacting 3-amino coumarin with various 2-aryl-1-nitro-ethenes and 1-phenyl-2-nitro-propene respectively in the presence of piperidine and methanol. The formation of furan and pyrrole nucleus in all above compounds follows Nef reaction mechanism. Using the Nef reaction, synthesis of various 1-aryl-1(H)-[1]benzopyrano[3,4,-b][1]benzpyrano[3’,4’-d]furan-7(H)-ones have been carried out by reacting various 4-hydroxy coumarins with various 3-nitro-2-aryl-2H-[1]benzopyrans in the presence of piperidine and methanol. Similarly synthesis of various 1-aryl-1(H)-[1]benzopyrano[3,4,-b][1]benzpyrano [3’,4’-d]pyrrole-7(H)-ones also have been carried out by reacting various 4-hydroxy coumarins with various 3-nitro-2-aryl-2H-[1]benzopyrans in the presence of ammoniun acetate and acetic acid.
Keywords: Furan, Pyrrolo,Coumarin, Benzopyrano
Use of Quadrupolar Nuclei for Quantum Information processing by Nuclear Magnetic Resonance: Implementation of a Quantum Algorithm
Physical implementation of Quantum Information Processing (QIP) by
liquid-state Nuclear Magnetic Resonance (NMR), using weakly coupled spin-1/2
nuclei of a molecule, is well established. Nuclei with spin1/2 oriented in
liquid crystalline matrices is another possibility. Such systems have multiple
qubits per nuclei and large quadrupolar couplings resulting in well separated
lines in the spectrum. So far, creation of pseudopure states and logic gates
have been demonstrated in such systems using transition selective
radio-frequency pulses. In this paper we report two novel developments. First,
we implement a quantum algorithm which needs coherent superposition of states.
Second, we use evolution under quadrupolar coupling to implement multi qubit
gates. We implement Deutsch-Jozsa algorithm on a spin-3/2 (2 qubit) system. The
controlled-not operation needed to implement this algorithm has been
implemented here by evolution under the quadrupolar Hamiltonian. This method
has been implemented for the first time in quadrupolar systems. Since the
quadrupolar coupling is several orders of magnitude greater than the coupling
in weakly coupled spin-1/2 nuclei, the gate time decreases, increasing the
clock speed of the quantum computer.Comment: 16 pages, 3 figure
Work function changes in the double layered manganite La1.2Sr1.8Mn2O7
We have investigated the behaviour of the work function of La1.2Sr1.8Mn2O7 as
a function of temperature by means of photoemission. We found a decrease of 55
+/- 10 meV in going from 60 K to just above the Curie temperature (125 K) of
the sample. Above T_C the work function appears to be roughly constant. Our
results are exactly opposite to the work function changes calculated from the
double-exchange model by Furukawa, but are consistent with other measurements.
The disagreement with double-exchange can be explained using a general
thermodynamic relation valid for second order transitions and including the
extra processes involved in the manganites besides double-exchange interaction.Comment: 6 pages, 4 figures included in tex
A Bayesian approach to modelling spectrometer data chromaticity corrected using beam factors -- I. Mathematical formalism
Accurately accounting for spectral structure in spectrometer data induced by
instrumental chromaticity on scales relevant for detection of the 21-cm signal
is among the most significant challenges in global 21-cm signal analysis. In
the publicly available EDGES low-band data set, this complicating structure is
suppressed using beam-factor based chromaticity correction (BFCC), which works
by dividing the data by a sky-map-weighted model of the spectral structure of
the instrument beam. Several analyses of this data have employed models that
start with the assumption that this correction is complete. However, while BFCC
mitigates the impact of instrumental chromaticity on the data, given realistic
assumptions regarding the spectral structure of the foregrounds, the correction
is only partial. This complicates the interpretation of fits to the data with
intrinsic sky models (models that assume no instrumental contribution to the
spectral structure of the data). In this paper, we derive a BFCC data model
from an analytic treatment of BFCC and demonstrate using simulated observations
that, in contrast to using an intrinsic sky model for the data, the BFCC data
model enables unbiased recovery of a simulated global 21-cm signal from
beam-factor chromaticity corrected data in the limit that the data is corrected
with an error-free beam-factor model.Comment: 26 pages, 8 figures; accepted for publication in MNRA
Magnetic anomalies in the spin chain system, SrCuZnIrO
We report the results of ac and dc magnetization (M) and heat-capacity (C)
measurements on the solid solution, SrCuZnIrO. While the Zn
end member is known to form in a rhombohedral pseudo one-dimensional
KCdCl structure with an antiferromagnetic ordering temperature of
(T =) 19 K, the Cu end member has been reported to form in a monoclinically
distorted form with a Curie temperature of (T =) 19 K. The magnetism of the
Zn compound is found to be robust to synthetic conditions and is broadly
consistent with the behavior known in the literature. However, we find a lower
magnetic ordering temperature (T) for our Cu compound (~ 13 K), thereby
suggesting that T is sensitive to synthetic conditions. The Cu sample
appears to be in a spin-glass-like state at low temperatures, judged by a
frequency dependence of ac magnetic susceptibility and a broadening of the C
anomaly at the onset of magnetic ordering, in sharp contrast to earlier
proposals. Small applications of magnetic field, however, drive this system to
ferromagnetism as inferred from the M data. Small substitutions for Cu/Zn (x =
0.75 or 0.25) significantly depress magnetic ordering; in other words, T
varies non-monotonically with x (T ~ 6, 3 and 4 K for x = 0.25, 0.5, and
0.67 respectively). The plot of inverse susceptibility versus temperature is
non-linear in the paramagnetic state as if correlations within (or among) the
magnetic chains continuously vary with temperature. The results establishComment: 7 pages, 7 figures, Revte
Spectroscopic and Mechanistic Studies of Heterodimetallic Forms of Metallo-β-lactamase NDM-1
In an effort to characterize the roles of each metal ion in metallo-β-lactamase NDM-1, heterodimetallic analogues (CoCo-, ZnCo-, and CoCd-) of the enzyme were generated and characterized. UV–vis, 1H NMR, EPR, and EXAFS spectroscopies were used to confirm the fidelity of the metal substitutions, including the presence of a homogeneous, heterodimetallic cluster, with a single-atom bridge. This marks the first preparation of a metallo-β-lactamase selectively substituted with a paramagnetic metal ion, Co(II), either in the Zn1 (CoCd-NDM-1) or in the Zn2 site (ZnCo-NDM-1), as well as both (CoCo-NDM-1). We then used these metal-substituted forms of the enzyme to probe the reaction mechanism, using steady-state and stopped-flow kinetics, stopped-flow fluorescence, and rapid-freeze-quench EPR. Both metal sites show significant effects on the kinetic constants, and both paramagnetic variants (CoCd- and ZnCo-NDM-1) showed significant structural changes on reaction with substrate. These changes are discussed in terms of a minimal kinetic mechanism that incorporates all of the data
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