2,405 research outputs found

    A smart material based approach to morphing

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    This presentation gives an overview of the Shape Memory Alloy (SMA) based approach to the research and13; development of adaptive/smart/morphing airframe structural technologies at the Advanced Composites13; Division, NAL. Central to this approach is the efficient integration of thermal NiTi SMA elements with13; polymeric carbon composites. The SMA elements could be either externally placed or embedded in the13; polymeric composite. The external connection could be in the form of mechanisms / devices

    Development and Wind Tunnel Evaluation of a SMA Based Trim Tab Actuator for a Civil Aircraft

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    This paper presents about the development and wind tunnel evaluation of an SMA based smart trim tab for a typical 2 seater civil aircraft. SMA actuator was housed in the port side of the elevator for actuating the trim tab. Wind tunnel tests were conducted on a full scale Horizontal Tail model with Elevator and Trim Tab at free stream speeds of 25, 35 & 45 m/sec and also for a number of deflections of the elevator (30° up, 0° neutral & 25° down) and trim-tab 11° & 21° up and 15° & 31° down). To measure the hinge moment experienced by the trim-tab at various test conditions, two miniaturized balances were designed and fabricated. Gain scheduled proportional integral controller was developed to control the SMA actuated smart trim tab. It was confirmed during the tests that the trim-tab could be controlled at the desired position against the aerodynamic loads acting on it for the various test conditions

    Occurrence of Gastrointestinal Helminths in rabbits with special Reference to Importance of Giardia spp. as Parasitic Zoonoses

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    The aim of this study was to detect Giardia spp. as zoonotic helminth as Giardiosis has been recognised as the one of the important parasitic  diarrhoea among children as cross transmission may occur between human  and rabbits. Other helminths in rabbits may causes ill health and sometimes proved fatal. Faecal samples of 42 rabbits of different age group (1-4 years)  from Nagpur and Akola regions, India were examined. The study was  conducted during June to August 2008. Faecal sample examination revealed  presence of mixed infection of eggs of parasites like Giardia spp. (19.04%), Trichostrongyle spp. (28.57%), Graphidium spp. (19.04%), Coccidia spp. (16.66%) and Passaluras spp. (14.28%)

    DESIGN NOVEL SYNTHETIC ROOT OF BENZOXAZOLE DERIVATIVES AS IN VITRO ACTIVITIES: A RESEARCH ARTICLE

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    Being a hetero- cyclic moiety, benzoxazole finds application in much medicinal research as an initial reactant. Benzoxazole derivatives have unique significance in the field of medical research due to their incredible biological potential. During recent year Benzoxazole derivative showed interesting development in medicinal research. Many Novel benzoxazole derivatives (G3-G6) were formed by using 4- methyl 2-amiono phenol reagent with methanol, potassium hydroxide, carbon di- sulfide. We observed the process employing thin-layer chromatography and interpreted spectral analysis via NMR, LC-MS, IR Spectrometry and antibacterial activity done by MIC method with Escherichia Coli a gram negative bacteria, Staphylococcus aureus a gram positive bacteria and anti-tubercular activities done through alamar blue dye technique(ABD) using Mycobacterium Tuberculosis(MT) bacteria . Some tested derivatives showed potent activit

    Attitude of Dental Students towards Their Oral Health Care

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    ABSTRACT Dental students have a major role in dental health promotion not only through their skills but also as a role model for the general population. Therefore, this study intended to evaluate the attitude of undergraduate dental students towards their self oral care. This study also intended to find out the difference in attitude between the genders and between the students in the preclinical and clinical year. This is a questionnaire based study conducted in four colleges in Bangalore. The study was conducted using a modified version of HU-DBI questionnaire. The participants gave their responses according to five point Likert scale. High scores denoted the strength of positivity of the attitude. The data was analyzed using SPSS. Student t-test was used to find the significance level. Questionnaire was distributed to 430 students, out of which 421 students answered, that included consisted of 191 females (45.4%) and 230 males (54.6%). Among 421 participants, 199 participants (47.2%) belong to preclinical year of study and 222 (52.7%) from clinical year of study. Mean per question was higher in clinical year students when compared to preclinical year students, indicating the improvement in the attitude with the progress in the academic years. There was no significant difference in attitude between the genders towards the oral care. The current study shows that dental students show better attitude towards their dental care and they may form a better role model for the general population and patients

    Anti-malarial activity of Holarrhena antidysenterica and Viola canescens, plants traditionally used against malaria in the Garhwal region of north-west Himalaya

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    <p>Abstract</p> <p>Background</p> <p>The increasing number of multidrug-resistant <it>Plasmodium </it>strains warrants exploration of new anti-malarials. Medicinal plant research has become more important, particularly after the development of Chinese anti-malarial drug artemisnin from <it>Artemisia annua</it>. The present study shows evaluation of anti-malarial effects of two plants commonly used against malaria in the Garhwal region of north-west Himalaya, in order to discover the herbal-based medicine.</p> <p>Methods</p> <p><it>In vitro </it>anti-plasmodial sensitivity of plant extracts was assessed using schizont maturation and parasite lactate dehydrogenase (pLDH) assay. Cytotoxic activities of the examined extracts were determined on L-6 cells of rat skeletal muscle myoblast. The 4-day test for anti-malarial activity against a chloroquine sensitive <it>Plasmodium berghei </it>NK65 strain in Swiss albino mice was used for monitoring <it>in vivo </it>activity of plant extracts.</p> <p>Results</p> <p>Chloroform extract of <it>H. antidysenterica </it>(HA-2) and petroleum ether extract of <it>V. canescens </it>(VC-1) plants significantly reduced parasitaemia in <it>P. berghei </it>infected mice. The extract HA-2 showed <it>in vitro </it>anti-plasmodial activity with its IC<sub>50 </sub>value 5.5 μg/ml using pLDH assay and ED<sub>50 </sub>value 18.29 mg/kg in <it>P. berghei </it>infected Swiss albino mice. Similarly petroleum ether extract of <it>V. canescens </it>(VC-1) showed <it>in vitro </it>anti-plasmodial activity with its IC<sub>50 </sub>value 2.76 μg/ml using pLDH assay and ED<sub>50 </sub>15.8 mg/kg in <it>P. berghei </it>infected mice. The extracts coded as HA-2 at 30 mg/kg and VC-1 at 20 mg/kg exhibited parasite inhibition in mice: 73.2% and 63.0% respectively. Of these two plant extracts, petroleum ether extract of <it>V. canescens </it>was found slightly cytotoxic.</p> <p>Conclusion</p> <p>The present investigation reflects the use of these traditional medicinal plants against malaria and these plants may work as potential source in the development of variety of herbal formulations for the treatment of malaria.</p

    Comparison of cardiovascular risk factors between sri lankans living in kandy and oslo

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    <p>Abstract</p> <p>Background</p> <p>South Asians living in western countries are known to have unfavourable cardiovascular risk profiles. Studies indicate migrants are worse off when compared to those living in country of origin. The purpose of this study was to compare selected cardiovascular risk factors between migrant Sri Lankans living in Oslo, Norway and Urban dwellers from Kandy, Sri Lanka.</p> <p>Methods</p> <p>Data on non fasting serum lipids, blood pressure, anthropometrics and socio demographics of Sri Lankan Tamils from two almost similar population based cross sectional studies in Oslo, Norway between 2000 and 2002 (1145 participants) and Kandy, Sri Lanka in 2005 (233 participants) were compared. Combined data were analyzed using linear regression analyses.</p> <p>Results</p> <p>Men and women in Oslo had higher HDL cholesterol. Men and women from Kandy had higher Total/HDL cholesterol ratios. Mean waist circumference and body mass index was higher in Oslo. Smoking among men was low (19.2% Oslo, 13.1% Kandy, P = 0.16). None of the women smoked. Mean systolic and diastolic blood pressure was significantly higher in Kandy than in Oslo.</p> <p>Conclusions</p> <p>Our comparison showed unexpected differences in risk factors between Sri Lankan migrants living in Oslo and those living in Kandy Sri Lanka. Sri Lankans in Oslo had favorable lipid profiles and blood pressure levels despite being more obese.</p

    Transgenic tobacco plants constitutively expressing Arabidopsis NPR1 show enhanced resistance to root-knot nematode, Meloidogyne incognita

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    In Arabidopsis, non-expressor of pathogenesis related genes-1, NPR1 has been shown to be a positive regulator of the salicylic acid controlled systemic acquired resistance pathway and modulates the cross talk between SA and JA signaling. Transgenic plants expressing AtNPR1 constitutively exhibited resistance against pathogens as well as herbivory. In the present study, tobacco transgenic plants expressing AtNPR1 were studied further for their response to infection by the sedentary endoparasitic root knot nematode, Meloidogyne incognita. Transgenic plants showed enhanced resistance against the root-knot nematode infection. Prominent differences in the shoot and root weights of wild type and transgenic plants were observed post-inoculation with M. incognita. This was associated with a decrease in the number of root galls and egg masses in transgenic plants compared to WT. The transgenic plants also showed constitutive and induced expression of some PR protein genes, when challenged with M. incognita

    Structural insights into the production of 3-hydroxypropionic acid by aldehyde dehydrogenase from Azospirillum brasilense

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    3-Hydroxypropionic acid (3-HP) is an important platform chemical to be converted to acrylic acid and acrylamide. Aldehyde dehydrogenase (ALDH), an enzyme that catalyzes the reaction of 3-hydroxypropionaldehyde (3-HPA) to 3-HP, determines 3-HP production rate during the conversion of glycerol to 3-HP. To elucidate molecular mechanism of 3-HP production, we determined the first crystal structure of a 3-HP producing ALDH, alpha-ketoglutarate-semialdehyde dehydrogenase from Azospirillum basilensis (AbKGSADH), in its apo-form and in complex with NAD(+). Although showing an overall structure similar to other ALDHs, the AbKGSADH enzyme had an optimal substrate binding site for accepting 3-HPA as a substrate. Molecular docking simulation of 3-HPA into the AbKGSADH structure revealed that the residues Asn159, Gln160 and Arg163 stabilize the aldehyde-and the hydroxyl-groups of 3-HPA through hydrogen bonds, and several hydrophobic residues, such as Phe156, Val286, Ile288, and Phe450, provide the optimal size and shape for 3-HPA binding. We also compared AbKGSADH with other reported 3-HP producing ALDHs for the crucial amino acid residues for enzyme catalysis and substrate binding, which provides structural implications on how these enzymes utilize 3-HPA as a substrate

    Piperidinols that show anti-tubercular activity as inhibitors of arylamine N-acetyltransferase: an essential enzyme for mycobacterial survival inside macrophages

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    Latent M. tuberculosis infection presents one of the major obstacles in the global eradication of tuberculosis (TB). Cholesterol plays a critical role in the persistence of M. tuberculosis within the macrophage during latent infection. Catabolism of cholesterol contributes to the pool of propionyl-CoA, a precursor that is incorporated into cell-wall lipids. Arylamine N-acetyltransferase (NAT) is encoded within a gene cluster that is involved in the cholesterol sterol-ring degradation and is essential for intracellular survival. The ability of the NAT from M. tuberculosis (TBNAT) to utilise propionyl-CoA links it to the cholesterol-catabolism pathway. Deleting the nat gene or inhibiting the NAT enzyme prevents intracellular survival and results in depletion of cell-wall lipids. TBNAT has been investigated as a potential target for TB therapies. From a previous high-throughput screen, 3-benzoyl-4-phenyl-1-methylpiperidinol was identified as a selective inhibitor of prokaryotic NAT that exhibited antimycobacterial activity. The compound resulted in time-dependent irreversible inhibition of the NAT activity when tested against NAT from M. marinum (MMNAT). To further evaluate the antimycobacterial activity and the NAT inhibition of this compound, four piperidinol analogues were tested. All five compounds exert potent antimycobacterial activity against M. tuberculosis with MIC values of 2.3-16.9 µM. Treatment of the MMNAT enzyme with this set of inhibitors resulted in an irreversible time-dependent inhibition of NAT activity. Here we investigate the mechanism of NAT inhibition by studying protein-ligand interactions using mass spectrometry in combination with enzyme analysis and structure determination. We propose a covalent mechanism of NAT inhibition that involves the formation of a reactive intermediate and selective cysteine residue modification. These piperidinols present a unique class of antimycobacterial compounds that have a novel mode of action different from known anti-tubercular drugs
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