601 research outputs found
Synthesis and Liquid Crystalline Studies of 2,4-bis(4'-n-nonyloxybenzoyloxy)benzylidene-4''-n-alkoxyaniline
In this paper, a series of new Schiff-bases: 2,4-bis(4âânânonyloxy -benzoyloxy)benzylidene-4ââ-n-alkyloxyaniline (DC9An) were synthesized. The characterization of compounds was achieved through using (ultra violet, infrared, 1H-nuclear magnetic resonance) measurements. This series comprises 10 members differ by the length of n-alkoxy chain (i.e., OCnH2n+1, n=1-10). Their liquid crystalline properties were studied using differential scanning calorimetry and polarizing optical microscopy. The lower series such as n=1-3 are purely nematogenic liquid crystals, but the other means (n=4-7) have nematic and smectic phases (SmC and SmA). The higher members (n=8-10) are purely smectogenic liquid crystals
Selective preservation of protein kinase C-ζ in the chemoprevention of azoxymethane-induced colonic tumors by piroxicam
AbstractWhile nonsteroidal anti-inflammatory drugs have been shown to exert preventive effects against the development of colonic tumors in humans and in chemically-induced tumors in animal models, the mechanism(s) involved in this phenomenon is unclear. We have recently demonstrated that one such agent, piroxicam, when supplemented (75 ppm) in the diets of rats administered azoxymethane, reduced the incidence of rats bearing tumors. To date, the effects of piroxicam on protein kinase C, a family of serine/threonine kinases which may be intimately involved in the colonic malignant transformation process, have not been examined. It was, therefore, of interest to determine whether piroxicam altered the expression of one or more isoforms of this kinase in these tumors. The present studies demonstrate that dietary piroxicam selectively preserved the expression of protein kinase C-ζ in azoxymethane-induced tumors; suggesting that this is at least one mechanism involved in this agent's chemopreventive actions in this organ
Heating up the cold bounce
Self-dual string cosmological models provide an effective example of bouncing
solutions where a phase of accelerated contraction smoothly evolves into an
epoch of decelerated Friedmann--Robertson--Walker expansion dominated by the
dilaton. While the transition to the expanding regime occurs at sub-Planckian
curvature scales, the Universe emerging after the bounce is cold, with sharply
growing gauge coupling. However, since massless gauge bosons (as well as other
massless fields) are super-adiabatically amplified, the energy density of the
maximally amplified modes re-entering the horizon after the bounce can
efficiently heat the Universe. As a consequence the gauge coupling reaches a
constant value, which can still be perturbative.Comment: 28 pages, 13 figure
Conversion to sirolimus for chronic renal allograft dysfunction: risk factors for graft loss and severe side effects
We retrospectively reviewed our experience with 45 kidney transplant recipients (KTR) that were switched from CNI to SRL, mainly for chronic allograft dysfunction (CAD) (41/45). The mean serum creatinine at switch was 2.5 ± 0.8 mg/dl. At 1 year, patient survival was 93%. Death-censored graft survival was 67% at 1 year and 54% at 2 years. SRL was stopped because of severe side effects in 15 patients. Among these, eight patients developed âde novoâ high-grade proteinuria. Univariate analysis revealed that (1) a higher SRL level at 1 month was a predictor of SRL withdrawal due to severe side effects (P = 0.006), and (2) predictors of graft failure after SRL conversion were low SRL loading dose (P = 0.03) and a higher creatinine level at conversion (P = 0.003)
Non-Abelian Monopole and Dyon Solutions in a Modified Einstein-Yang-Mills-Higgs System
We have studied a modified Yang-Mills-Higgs system coupled to Einstein
gravity. The modification of the Einstein-Hilbert action involves a direct
coupling of the Higgs field to the scalar curvature. In this modified system we
are able to write a Bogomol'nyi type condition in curved space and demonstrate
that the positive static energy functional is bounded from below. We then
investigate non-Abelian sperically symmetric static solutions in a similar
fashion to the `t Hooft-Polyakov monopole. After reviewing previously studied
monopole solutions of this type, we extend the formalism to included electric
charge and we present dyon solutions.Comment: 18 pages LaTeX, 7 eps-figure
Evidence for facultative migratory flight behavior in Helicoverpa armigera (Noctuidae: Lepidoptera) in India
Despite its deleterious impact on farming and agriculture, the physiology and energetics of insect migration is poorly understood due to our inability to track their individual movements in the field. Many insects, e.g. monarch butterflies, Danaus plexippus (L.), are facultative migrants. Hence, it is important to establish whether specific insect populations in particular areas migrate. The polyphagous insect, Helicoverpa armigera (Hubner), is especially interesting in this regard due to its impact on a variety of crops. Here, we used a laboratory based flight mill assay to show that Helicoverpa armigera populations clearly demonstrate facultative migration in South India. Based on various flight parameters, we categorized male and female moths as long, medium or short distance fliers. A significant proportion of moths exhibited long-distance flight behaviour covering more than 10 km in a single night, averaging about 8 flight hours constituting 61% flight time in the test period. The maximum and average flight speeds of these long fliers were greater than in the other categories. Flight activity across sexes also varied; male moths exhibited better performance than female moths. Wing morphometric parameters including forewing length, wing loading, and wing aspect ratio were key in influencing long-distance flight. Whereas forewing length positively correlated with flight distance and duration, wing loading was negatively correlated
Correction of abnormal small intestinal cytosolic protein kinase C activity in streptozotocin-induced diabetes by insulin therapy
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The relationship between stimulus intensity and response amplitude for the photopic negative response of the flash electroretinogram
The aim of this study was to investigate the relationship between stimulus intensity and response amplitude for the photopic negative response (PhNR) of the flash ERG. Specific aims were (i) to determine whether a generalized Naka-Rushton function provided a good fit to the intensity-response data and (ii) to determine the variability of the parameters of the best-fitting Naka-Rushton models. Electroretinograms were recorded in 18 participants, on two occasions, using both DTL fibre and skin active electrodes, in response to Ganzfeld red stimuli (Lee filter "terry red") ranging in stimulus strength from -1.30 to 0.53 log cd.s.m(-2) (0.28-2.11 log phot td.s) presented over a steady blue background (Schott glass filter BG28; 3.9 log scot td). PhNR amplitude was measured from b-wave peak and from pre-stimulus baseline. The Naka-Rushton function was fitted to all intensity-response data, and parameters, 'n', 'Vmax' and 'K' were obtained. Coefficients of variation (CoV), and inter-ocular and inter-session limits of agreement (LoA) were calculated for both Naka-Rushton parameters. A generalized Naka-Rushton function was found to provide a good fit to the intensity-response data, except at the highest stimulus intensity, where a reduction in amplitude occurred in many individuals. The 'Vmax' parameter was less variable than 'K' for all intensity-response data. Variability was lower for DTL than skin electrodes, and for peak-to-trough PhNR measurements, compared to baseline-to-trough. This study has demonstrated for the first time that the Naka-Rushton model provides a useful means of quantifying the intensity-response relationship of the PhNR
Epithelial immunomodulation by aerosolized Toll-like receptor agonists prevents allergic inflammation in airway mucosa in mice
Allergic asthma is a chronic inflammatory respiratory disease associated with eosinophilic infiltration, increased mucus production, airway hyperresponsiveness, and airway remodeling. Epidemiologic data reveal that the prevalence of allergic sensitization and associated diseases has increased in the twentieth century. This has been hypothesized to be partly due to reduced contact with microbial organisms (the hygiene hypothesis) in industrialized society. Airway epithelial cells, once considered a static physical barrier between the body and the external world, are now widely recognized as immunologically active cells that can initiate, maintain, and restrain inflammatory responses, such as those that mediate allergic disease. Airway epithelial cells can sense allergens via expression of myriad Toll-like receptors (TLRs) and other pattern-recognition receptors. We sought to determine whether the innate immune response stimulated by a combination of Pam2CSK4 (âPam2â, TLR2/6 ligand) and a class C oligodeoxynucleotide ODN362 (âODNâ, TLR9 ligand), when delivered together by aerosol (âPam2ODNâ), can modulate the allergic immune response to allergens. Treatment with Pam2ODN 7 days before sensitization to House Dust Mite (HDM) extract resulted in a strong reduction in eosinophilic and lymphocytic inflammation. This Pam2ODN immunomodulatory effect was also seen using Ovalbumin (OVA) and A. oryzae (Ao) mouse models. The immunomodulatory effect was observed as much as 30 days before sensitization to HDM, but ineffective just 2 days after sensitization, suggesting that Pam2ODN immunomodulation lowers the allergic responsiveness of the lung, and reduces the likelihood of inappropriate sensitization to aeroallergens. Furthermore, Pam2 and ODN cooperated synergistically suggesting that this treatment is superior to any single agonist in the setting of allergen immunotherapy
Genetic analysis of recombinant inbred lines for iron deficiency chlorosis and productivity traits in groundnut
Iron deficiency is an important abiotic constraint reducing
the growth and yield of groundnut especially under
calcareous soils. Foliar application of Fe-chelates can
overcome iron deficiency but it is not economical.
Evaluation of 318 recombinant inbred lines (RILs) along
with parents for iron deficiency chlorosis (IDC) and
productivity traits under iron deficient soils over three years
indicated significant genotypic and genotypic x
environment interaction (GE) component for both IDC and
productivity traits. Among the RILs, range of variation was
higher than that of the parents for visual chlorotic rating
(VCR), SPAD chlorophyll meter reading (SCMR) and
productivity parameters across three years indicated the
presence of transgressive segregants. VCR had higher
phenotypic and genotypic, variances, heritability and
genetic advance as per cent of mean (GAM) in all the three
years as compared to SCMR. Among productivity traits,
pod yield (g plantâ1) had higher PCV and GCV compared to
shelling per cent and 100 seed weight. Significant negative
correlation between VCR and pod yield per plant indicated
effect of IDC on productivity in RILs. Nine lines were
superior for both IDC tolerance and productivity traits. This
extensive phenotyping of RIL population for IDC tolerance
under iron deficient conditions can be used for
identification of genomic regions associated with IDC
tolerance by genotyping of this RIL population
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