Rajasree, K; Ravikumar, A V; Radhakrishnan, P; Nampoori, V P N; Vallabhan, C P G(Springer, April , 1992)
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Abstract:
Photothermal deflection technique was used for determining the laser damage threshold of polymer samples of teflon (PTFE) and nylon. The experiment was conducted using a Q-switched Nd-YAG laser operating at its fundamental wavelength (1-06μm, pulse width 10 nS FWHM) as irradiation source and a He-Ne laser as the probe beam, along with a position sensitive detector. The damage threshold values determined by photothermal deflection method were in good agreement with those determined by other methods.
Syamaprasad, U; Vallabhan, C P G(Institute of Physics, 1981)
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Abstract:
Four distinct peaks are observed at 140, -26, -132 and -140°C in the sigma x* against T-1 plot between 200 and - 196°C for (NH4)3H(SO4)2, corresponding to four different phase
transitions of which the one at -26°C is reported here for the first time. Data on doped
samples reveal the charge transport mechanism in the crystal.
Eswar Shankar,P N; Anu,Joseph; Paulose,C S(Department of Biotechnology, May 17, 2006)
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Abstract:
In the present study dopamine was measured in the hypothalamus, brainstem, pancreatic islets and plasma, using HPLC. Dopamine D2 receptor
changes in the hypothalamus, brainstem and pancreatic islets were studied using [3H] YM-09151-2 in streptozotocin-induced diabetic and insulintreated
diabetic rats. There was a significant decrease in dopatnine content in the hypothalamus (P<0.001), brainstem (P<0.001), pancreatic islets
(P<0.001) and plasma (P<0.00I) in diabetic rats when compared to control. Scatchard analysis of [3H] YM-09151-2 in the hypothalamus of
diabetic rats showed a significant decrease in Bax (P<0.001) and Kd, showing an increased affinity of D2 receptors when compared to control.
Insulin treatment did not completely reverse the changes that occurred during diabetes. There was a significant decrease in B,nax (P<0.01) with
decreased affinity in the brainstem of diabetic rats. The islet membrane preparation of diabetic rats showed a significant decrease (P<0.001) in the
binding of [3H] YM-09 151-2 with decreased Kd (P<0.001) compared to control. The increase in affinity of D2 receptors in hypothalamus and
pancreatic islets and the decreased affinity in brainstem were confirmed by competition analysis. Thus our results suggest that the decreased
dopamine D, receptor function in the hypothalamus, brainstem and pancreas affects insulin secretion in diabetic rats, which has immense clinical
relevance to the management of diabetes.
Mohanan,Valiyaveettil; Balarama Kaimal,S; Paulose,Cheramadathikudyil S(Department of Bio Technology, August 30, 2004)
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Abstract:
The present study was to investigate the rote of central 5-11T and 5-HT,:v receptor Lindin4o
and acne expression in it 'at mo(lel of pancreatic regeneration using 60" -, pancreatcutumy.
The pancreatic regeneration was evaluated by 5-HT content and 5-HT,,receptor gene
expression in the cerebral cortex (CC) and brain stem MS) of Alain opcrate,t, 7 It utd
7 (.lays panereatectomised rats. 5-11T content significantly increased in the CC' (I' 1.1)11
and 13S (P 0.05) of 72 Ii p.ntcreateetomiscd rats. Sympathetic activity was decreased as
indicated by the significantly decreased norcpiuephrine (NIi) and epinephrine (FTI) Icvcl
(1' < 0.001 and P < 0.05) in the plasma of 72 h panereateetomised rats. 5-111 ,^, receptor
density and affinity was decreased in the CC (P < 0.01) and BS (P < 0.01). These rh:)nge;
correlated with a diminished 5-IITIA receptor mRNA expression in the brain region. studied.
Our resuils suggest that the brain 5-11T through 5-HTin receptor has it funcuon:0 rule
iii 11w pi+ncreatic regcner:ttion through the sympathetic regulation.
Mohanan, Valiya Veettil; Finla, Chathu; Paulose, Cheramadathikudyil S(Department of Bio Technology, December 1, 2004)
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Abstract:
The purpose of this study was to investigate the role of central 5-HT2C receptor binding in rat model of pancreatic regeneration
using 60-70% pancreatectomy. The 5-HT and 5-HT2c receptor kinetics were studied in cerebral cortex and brain stem of sham
operated, 72 h pancreatectomised and 7 days pancreatectomised rats. Scatchard analysis with [3H] mesulergine in cerebral
cortex showed a significant decrease (p < 0.05) in maximal binding (B^,ax) without any change in Kd in 72 h pancreatectomised
rats compared with sham. The decreased Bmax reversed to sham level by 7 days after pancreatectomy. In brain stem , Scatchard
analysis showed a significant decrease (p < 0.01) in Bax with a significant increase (p < 0.01) in Kd. Competition analysis
in brain stem showed a shift in affinity towards a low affinity. These parameters were reversed to sham level by 7 days after
pancreatectomy. Thus the results suggest that 5-HT through the 5-HT2C receptor in the brain has a functional regulatory role in
the pancreatic regeneration. (Mol Cell Biochem 272: 165-170, 2005)
Ani Das, V; Finla, Chathu; Paulose, C S(Department of Bio Technology, April 20, 2006)
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Abstract:
Sympathetic stimulation inhibits insulin secretion. a2-Adrenergic receptor is known to have a regulatory role in the sympathetic function. We
investigated the changes in the a2-adrenergic receptors in the brain stein and pancreatic islets using [3H]Yohimbine during pancreatic regeneration
in weanling rats. Brain stem and pancreatic islets of experimental rats showed a significant decrease (p<0.001) in norepinephrine (NE) content at
72 h after partial pancreatectomy. The epinephrine (EPI) content showed a significant decrease (p<0.001) in pancreatic islets while it was not
detected in brain stem at 72 h after partial pancreatectomy. Scatchard analysis of [3H]Yohimbine showed a significant decrease
(p<0.05) and Kd at 72 h after partial pancreatectomy in the brain stem. In the pancreatic islets, Scatchard analysis of [3H]Yohimbine showed a signiinfiBca'nnatx
decrease (p<0.001) in B,nax and Kd (p<0.05) at 72 h after partial pancreatectomy. The binding parameters reversed to near sham by 7 days after
pancreatectomy both in brain stein and pancreatic islets. This shows that pancreatic insulin secretion is influenced by central nervous system inputs
from the brain stem. In vitro studies with yohimbine showed that the a2-adrenergic receptors are inhibitory to islet DNA synthesis and insulin
secretion. Thus our results suggest that decreased a2-adrenergic receptors during pancreatic regeneration functionally regulate insulin secretion
and pancreatic 13-cell proliferation in weanling rats.
Paulose, C S; Peeyush, K T; Anju, T R(Springer Science+Business Media, LLC 2009, 2009)
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Abstract:
Hypoxia in neonates can lead to biochemical
and molecular alterations mediated through changes in
neurotransmitters resulting in permanent damage to brain.
In this study, we evaluated the changes in the receptor
status of GABAA in the cerebral cortex and brainstem of
hypoxic neonatal rats and hypoxic rats supplemented with
glucose and oxygen using binding assays and gene
expression of GABAAa1 and GABAAc5. In the cerebral
cortex and brainstem of hypoxic neonatal rats, a significant
decrease in GABAA receptors was observed, which
accounts for the respiratory inhibition. Hypoxic rats sup-
plemented with glucose alone and with glucose and oxygen
showed, respectively, a reversal of the GABAA receptors,
andGABAAa1 and GABAAc5 gene expression to control.
Glucose acts as an immediate energy source thereby
reducing the ATP-depletion-induced increase in GABA
and oxygenation, which helps in encountering anoxia.
Resuscitation with oxygen alone was less effective in
reversing the receptor alterations. Thus, the results of this
study suggest that reduction in the GABAA receptors
functional regulation during hypoxia plays an important
role in mediating the brain damage. Glucose alone and
glucose and oxygen supplementation to hypoxic neonatal
rats helps in protecting the brain from severe hypoxic
damage.
Balarama Kaimal,S; Gireesh,G; Paulose,C S(Department of Biotechnology, January 4, 2007)
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Abstract:
Gamma amino outyric acid is a major
inhibitory neurotrarsr titter in the central nervous
system. In the preset study sv, Have investigate(' the
alteration of GABA receptor, In t he hrain stem of rats
during pancreatic regeneration. Three groups of rats
were used for the study: sham operated, 72 It and
7 days partially pancreatectonnsea. GABA was (juan-
(ified by [H]GABA receptor iispiacement method.
GABA receptor kin: 10, pat at i et•ers were studied by
using the binding of F'.](iAhA as ligand to the Triton
X-100 treated me,i1,;-:mes a1,J displacement with
unlabelled GABA. GhRA,v receptor activity was
studied by using the [` -1 h3cuculline and displacement
with unlabellecV euculline. ;.\13A content significantly
decreased (1' < (1.(101 ) it, 0-e brain stern during
the regeneration of pancreas. 'I hl, high affinity (IAI3A
receptor binding sho?:ed it sigii'f cant decrease in 131„.,\
(P < 11.01) and K,I 1).05) n 72 h and 7 days after
partial pancreatee 'timv. ";:flhicuculline hin(Iing
showed it signih eat, 'le ( r(, :,e in /Jn1,s and K,I
(P < 0.001) in 72 h pa^.rcreaw,, mised rats when compared
with sham wt--tt' as P,n and K,I reversed to
near sham after 7 da,s of pancreatectomv. The results
sugge,) that GAB A throur,r; ('GABA receptors in
brain Atcem has a regulatory uie during active regeneration
of pancreas which will have inunense clinical
significance in the treatment of cliahetcs.
Ani Das, V; Savitha, B; Paulose, C S(Department of Biotechnology, April 4, 2006)
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Abstract:
purpose of this study was to investigate the
role of brain al-adrenergic receptor binding in the rat model
of pancreatic regeneration using 60-70% pancre:dectorny.
The a, -adrenergic receptors kinetics was studied in the
cerebral cor:cx and brain stem of sham operated . 72 It pan-
crea(ectoinised and 7 days pancreatectomised rats. Scar
chard analysis with I `I I lprazocin in cerebral cartes and brain
stein showed a significant decrease (/' < 0.01). (P < 0.05)
in maximal binding ( 1),,,,,) with it significant decrease
(P < 0.001 ), ( P < 0.01) in the K,,in 72 It pancreatecto-
raised rats compared with sham , respectively . Competition
analysis in cerebral cortex and brain stem showed it shift in
affinity during pancreatic regeneration . The sympathetic
activity was decreased as indicated by the significantly de-
increased norepinephrine level in the plasma (P < 0.001),
cerebral cortex (P < 0.01) and brain stem (P < 0.001) of
72 h pancreatectomised rats compared to sham . Thus, from
our results it is suggested that the central a, -adrenergic
receptors have a functional role in the pancreatic regenera-
Lion mediated through the sympathetic pathway.
Unnikrishnan, K P; Jayan, Thomas; V P N Nampoori; Vallabhan, C P G(Elsevier, June , 2002)
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Abstract:
Here we report measurements of third-order susceptibility χ(3), figure of merit F defined as χ(3)/α (where α is the absorption coefficient) and second hyperpolarizability 〈γ〉 of some metal substituted phthalocyanines and a naphthalocyanine in solutions of dimethyl formamide using degenerate four wave mixing at 532 nm under nanosecond excitation. It was found that among samples investigated, bis-naphthalocyanine possessed the highest value of 〈γ〉 followed by the bis-phthalocyanine. This observation is explained on the basis that bis-naphthalocyanine followed by bis-phthalocyanine has higher degree of π electron conjugation.
Rare earth exchanged Na–Y zeolites,
H-mordenite, K-10 montmorillonite clay and amorphous
silica-alumina were effectively employed for the
continuous synthesis of nitriles. Dehydration of benzaldoxime
and 4-methoxybenzaldoxime were carried
out on these catalysts at 473 K. Benzonitrile (dehydration
product) was obtained in near quantitative yield
with benzaldoxime whereas; 4-methoxybenzaldoxime
produces both Beckmann rearrangement (4-methoxyphenylformamide)
as well as dehydration products
(4-methoxy benzonitrile) in quantitative yields. The
production of benzonitrile was near quantitative under
heterogeneous reaction conditions. The optimal protocol
allows nitriles to be synthesized in good yields
through the dehydration of aldoximes. Time on stream
(TOS) studies show decline in the activity of the catalysts
due to neutralization of acid sites by the basic reactant
and product molecules and water formed during the
dehydration of aldoximes.
Suresh V, Vettoor; Nandakumaran, V M(Physica C,Elsevier Science, 1992)
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Abstract:
The density of states and the low temperature specific heat of higb-Tc superconductors are calculated in a functional integral formalism using the slave boson technique. The manybody calculation in a saddle point approximation shows that the Iow energy
sector is dominated by 3 single band. The calculated values of density of states are in good agreement with experimental results.
Sreedevi,Menon K; Vasudevan,K; Aanandan,C K; Mohanan,P(Microwave and Optical Technology Letters, September 20, 2005)
[+]
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Abstract:
Propagation of electromagnetic waves through a microstrip
line with 2D electromagnetic baud gap (EBG) structures of different
geometrical shapes in the ground plane is investigated in this paper.
Using transmission-line theory, the design equations for EBG structures are calculated. The measured, numerical. and simulated results are in
gone) agreement
Suresh Kumar, P; Thomas Lee, S; Vallabhan, C P G; Nampoori, V P N; Radhakrishnan, P(Elsevier, 2002)
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Abstract:
The design and development of a cost-effective, simple, sensitive and portable LED based fiber optic evanescent wave sensor for simultaneously detecting trace amounts of chromium and nitrite in water are presented. In order to obtain the desired performance, the middle portions of two multimode plastic clad silica fibers are unclad and are used as the sensing elements in the two arms of the sensor. Each of the sensor arms is sourced by separate super bright green LEDs, which are modulated in a time-sharing manner and a single photo detector is employed for detecting these light signals. The performance and characteristics of this system clearly establish the usefulness of the technique for detecting very low concentrations of the dissolved contaminants.
Zachariah,E J; Vasudevan,K; Pravinkumar,P A; Mohanan,P; K G Nair(Indian Journal of Radio & Space Physics, February , 1984)
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Abstract:
The design, erection and evalution procedures for it microwave anechuic chamber competed at Cochin University for
antenna studies are presented the chamber has an average reflectivity level of - 32 dB on at X-band frequencies, and it i,
comparable to international standards.
Gopikrishna, M; Deepti Das, Krishna; Aanandan, C K; Mohanan, P; Vasudevan, K(Wiley InterScience, April , 2009)
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Abstract:
The design and performance of a stepped slot printed monopole antenna in the ultrawideband is presented in this article. Multiple resonances generated by the stepped slot geometry are matched in the ultrawideband using a modified microstrip feed. The impedance bandwidth (SWR < 2) of the antenna is from 3 to 11 GHz. Radiation patterns are stable and omnidirectional with appreciable gain throughout the band. Performance of the antenna is also analyzed in the time domain, which reveals good pulse handling capabilities. Compact geometry of the antenna allows easy commercial deployment.
Shynu, S V; Gijo, Augustin; Anandan, C K; Mohanan, P; Vasudevan, K(Progress In Electromagnetics Research, 2006)
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Abstract:
The design of a compact, single feed, dual frequency
dual polarized and electronically reconfigurable microstrip antenna is
presented in this paper. A square patch loaded with a hexagonal slot
having extended slot arms constitutes the fundamental structure of
the antenna. The tuning of the two resonant frequencies is realized by
varying the effective electrical length of the slot arms by embedding
varactor diodes across the slots. A high tuning range of 34.43%
(1.037–1.394 GHz) and 9.27% (1.359–1.485 GHz) is achieved for the
two operating frequencies respectively, when the bias voltage is varied
from 0 to −30 V. The salient feature of this design is that it uses no
matching networks even though the resonant frequencies are tuned in
a wide range with good matching below −10 dB. The antenna has an
added advantage of size reduction up to 80.11% and 65.69% for the two
operating frequencies compared to conventional rectangular patches.
Mathew, K T; Anil, Lonappan; Paul, Benzy; Thimothy, V O; Rajasekaran, C; Vinu, Thomas; Joe, Jacob(Wiley InterScience, January , 2009)
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Abstract:
This article reports a new in vitro bile analysis based on
the measurement of the dielectric properties at microwave frequencies.
The measurements were made using rectangular cavity perturbation
technique at the S-band of microwave frequency with the different samples
of bile obtained from healthy persons as well as from patients. It is
observed that an appreciable change in the dielectric properties of patient’s
samples with the normal healthy samples and these measurements
were in good agreement with clinical analysis. These results prove an
alternative in-vitro method of detecting bile abnormalities based on the
measurement of the dielectric properties of bile samples using microwaves
without surgical procedure.
Bagei, A M; Cetin, A E(IEE Electronics letters,UK, October 24, 2002)
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Abstract:
A method for computer- aided diagnosis of micro calcification clusters
in mammograms images presented . Micro calcification clus.eni which
are an early sign of bread cancer appear as isolated bright spots in
mammograms. Therefore they correspond to local maxima of
the image. The local maxima of the image is lint detected and they
are ranked according to it higher-order statistical test performed over
the sub band domain data