272 research outputs found
CORRELATION OF TWO PYRAZOLINE MOIETY IN A SINGLE MOLECULE VIA N-LINKAGE CONTAINING FLUORINE ATOM AS A SUBSTITUENT AND THEIR BIOLOGICAL SIGNIFICANCE
Objective: The aim of the present invention is to synthesize and find out the biological importance of the series of the designed pyrazoline compounds.
Methods: A series of 3-[3'-(2â€,4â€-dichloro-5â€-fluorophenyl)-5'-(2â€-furyl)-4', 5'-dihydro-1H-pyrazol-1'-yl]-5-substituted phenyl-2-pyrazolines (2a-j) and 1-Nitroso-3-[3'-(2â€,4â€-dichloro-5â€-fluorophenyl)-5'-(2â€-furyl)-4', 5'-dihydro-1H-pyrazol-1'-yl]-5-substituted phenyl-2-pyrazolines (3a-j) were prepared in moderate yields. The structures of both pyrazoline and N-nitroso pyrazoline derivatives have been characterized on the basis of physical properties of the molecule and satisfactory spectral (IR, 1H NMR) data. The antimicrobial activity of the compounds against some Gram (+) and Gram (–) bacteria is reported.
Results: The Moderate yield of the proposed compounds was obtained. Spectral analysis showed the structural confirmation of the synthesized compounds. Some of the compounds showed lower to moderate level of drug-like properties.
Conclusion: From the results of spectral data and microbial activity it has been concluded that the compounds were found to exhibit some functional lead properties; hence these compounds are worth to be considered as potential lead molecules for further study
Euler characteristic and quadrilaterals of normal surfaces
Let be a compact 3-manifold with a triangulation . We give an
inequality relating the Euler characteristic of a surface normally embedded
in with the number of normal quadrilaterals in . This gives a relation
between a topological invariant of the surface and a quantity derived from its
combinatorial description. Secondly, we obtain an inequality relating the
number of normal triangles and normal quadrilaterals of , that depends on
the maximum number of tetrahedrons that share a vertex in .Comment: 7 pages, 1 figur
Takayasu arteritis in pregnancy: a case report, and clinical lessons learnt
A case report of known case of Takayasu arteritis (known to the woman in case report) in a primigravida, but unrevealed to the obstetrician till advanced stage of pregnancy is reported. The authors share the lessons learnt by them from this case which would improve diagnosis, evaluation and management of pregnancy hypertension. A brief account on clinical manifestations and diagnosis of Takayasu arteritis is also included
The Early Evolution of Magnetar Rotation I: Slowly Rotating "Normal" Magnetars
In the seconds following their formation in core-collapse supernovae,
"proto"-magnetars drive neutrino-heated magneto-centrifugal winds. Using a
suite of two-dimensional axisymmetric MHD simulations, we show that relatively
slowly rotating magnetars with initial spin periods of ms
spin down rapidly during the neutrino Kelvin-Helmholtz cooling epoch. These
initial spin periods are representative of those inferred for normal Galactic
pulsars, and much slower than those invoked for gamma-ray bursts and
super-luminous supernovae. Since the flow is non-relativistic at early times,
and because the Alfv\'en radius is much larger than the proto-magnetar radius,
spindown is millions of times more efficient than the typically-used dipole
formula. Quasi-periodic plasmoid ejections from the closed zone enhance
spindown. For polar magnetic field strengths G, the
spindown timescale can be shorter than than the Kelvin-Helmholtz timescale. For
G, it is of order seconds in early phases. We compute the
spin evolution for cooling proto-magnetars as a function of ,
, and mass (). Proto-magnetars born with greater than
spin down to periods s in just the first few seconds of
evolution, well before the end of the cooling epoch and the onset of classic
dipole spindown. Spindown is more efficient for lower and for larger
. We discuss the implications for observed magnetars, including the
discrepancy between their characteristic ages and supernova remnant ages.
Finally, we speculate on the origin of 1E 161348-5055 in the remnant RCW 103,
and the potential for other ultra-slowly rotating magnetars.Comment: 16 pages, 10 figure
Improving Diversity with Adversarially Learned Transformations for Domain Generalization
To be successful in single source domain generalization, maximizing diversity
of synthesized domains has emerged as one of the most effective strategies.
Many of the recent successes have come from methods that pre-specify the types
of diversity that a model is exposed to during training, so that it can
ultimately generalize well to new domains. However, na\"ive diversity based
augmentations do not work effectively for domain generalization either because
they cannot model large domain shift, or because the span of transforms that
are pre-specified do not cover the types of shift commonly occurring in domain
generalization. To address this issue, we present a novel framework that uses
adversarially learned transformations (ALT) using a neural network to model
plausible, yet hard image transformations that fool the classifier. This
network is randomly initialized for each batch and trained for a fixed number
of steps to maximize classification error. Further, we enforce consistency
between the classifier's predictions on the clean and transformed images. With
extensive empirical analysis, we find that this new form of adversarial
transformations achieve both objectives of diversity and hardness
simultaneously, outperforming all existing techniques on competitive benchmarks
for single source domain generalization. We also show that ALT can naturally
work with existing diversity modules to produce highly distinct, and large
transformations of the source domain leading to state-of-the-art performance.Comment: WACV 2023. Code: https://github.com/tejas-gokhale/AL
Attribute-Guided Adversarial Training for Robustness to Natural Perturbations
While existing work in robust deep learning has focused on small pixel-level
norm-based perturbations, this may not account for perturbations encountered in
several real-world settings. In many such cases although test data might not be
available, broad specifications about the types of perturbations (such as an
unknown degree of rotation) may be known. We consider a setup where robustness
is expected over an unseen test domain that is not i.i.d. but deviates from the
training domain. While this deviation may not be exactly known, its broad
characterization is specified a priori, in terms of attributes. We propose an
adversarial training approach which learns to generate new samples so as to
maximize exposure of the classifier to the attributes-space, without having
access to the data from the test domain. Our adversarial training solves a
min-max optimization problem, with the inner maximization generating
adversarial perturbations, and the outer minimization finding model parameters
by optimizing the loss on adversarial perturbations generated from the inner
maximization. We demonstrate the applicability of our approach on three types
of naturally occurring perturbations -- object-related shifts, geometric
transformations, and common image corruptions. Our approach enables deep neural
networks to be robust against a wide range of naturally occurring
perturbations. We demonstrate the usefulness of the proposed approach by
showing the robustness gains of deep neural networks trained using our
adversarial training on MNIST, CIFAR-10, and a new variant of the CLEVR
dataset.Comment: AAAI 2021. Camera Ready version + Appendi
The early evolution of magnetar rotation -- II. Rapidly rotating magnetars: Implications for Gamma-Ray Bursts and Super Luminous Supernovae
Rapidly rotating magnetars have been associated with gamma-ray bursts (GRBs)
and super-luminous supernovae (SLSNe). Using a suite of 2D magnetohydrodynamic
simulations at fixed neutrino luminosity and a couple of evolutionary models
with evolving neutrino luminosity and magnetar spin period, we show that
magnetars are viable central engines for powering GRBs and SLSNe. We also
present analytic estimates of the energy outflow rate from the proto-neutron
star (PNS) as a function of polar magnetic field strength , PNS angular
velocity , PNS radius and mass outflow rate
. We show that rapidly rotating magnetars with spin periods
ms and polar magnetic field strength
G can release ergs of energy during the first
s of the cooling phase. Based on this result, it is plausible that sustained
energy injection by magnetars through the relativistic wind phase can power
GRBs. We also show that magnetars with moderate field strengths of G do not release a large fraction of their rotational kinetic
energy during the cooling phase and hence, are not likely to power GRBs.
Although we cannot simulate to times greater than s after a
supernova, we can hypothesize that moderate field strength magnetars can
brighten the supernova light curves by releasing their rotational kinetic
energy via magnetic dipole radiation on timescales of days to weeks, since
these do not expend most of their rotational kinetic energy during the early
cooling phase.Comment: 15 pages, 13 Figure
A case of pulmonary hemorrhage and renal failure
Background:
Alveolar hemorrhage can be seen in many vasculitic disorders. However, granulomatosis polyangiitis (formerly Wegener’s granulomatosis) uncommonly presents with life threatening alveolar hemorrhage and has only been discussed in a few case reports [1].
Case Presentation:
A 53 year old Caucasian male presented with hemoptysis and profound anemia. Two weeks prior, he had presented with abdominal pain with normal renal function and numerous pulmonary nodules. During the current admission, the patient was hypoxic with acute renal failure requiring hemodialysis. Urine sediment demonstrated dysmorphic red blood cells. A bronchoscopy revealed diffuse alveolar hemorrhage. The diagnosis of pulmonary-renal syndrome was made and therapeutic plasma exchange was initiated. Laboratory studies were significant for a c-ANCA titer positive at 1:640 FIU and anti-proteinase (PR)-3 antibody titer positive with 78.3 U/ml. Renal biopsy demonstrated necrotizing crescentic glomerulonephritis. A diagnosis of granulomatosis vasculitis was determined.
Conclusion:
Alveolar hemorrhage is rare to be the presenting symptom of granulomatosis vasculitis where the common presenting features are recurrent sinusitis, epistaxis, chronic otitis media or rhinitis. Physicians should consider granulomatosis vasculitis in the differential diagnosis of pulmonary-renal syndrome presenting with hemoptysis
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