845 research outputs found

    Sinteza i anthelmintičko djelovanje novih 2-supstituiranih-4,5-difenil imidazola

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    A series of 2-substituted-4,5-diphenyl imidazoles 1a-j were synthesized by refluxing benzil with different substituted aldehydes in the presence of ammonium acetate and glacial acetic acid. Structures of the synthesized compounds were confirmed on the basis of IR, 1H NMR and mass spectral data. Compounds 1a-j were screened for anthelmintic activity. Test results revealed that compounds showed paralysis time of 0.24 to 1.54 s and death time of 0.39 to 4.40 s while the standard drugs albendazole and piperazine citrate showed paralysis time of 0.54 and 0.58 s and death time of 2.16 and 2.47 s, respectively, at the same concentration of 1 % (m/V). Five compounds, 2-[2-hydroxyphenyl]-4,5-diphenyl imidazole (1b), 2-[3-methoxyphenyl]-4,5-diphenyl imidazole (1c), 2-[2-phenylethenyl]-4,5-diphenyl imidazole (1e), 2-[4-fluorophenyl]-4,5-diphenyl imidazole (1g) and 2-[3-nitrophenyl]-4,5-diphenyl imidazole (1h) showed significant anthelmintic activity compared to the standard drugs.Refluksiranjem benzila s različitim supstituiranim aldehidima u prisutnosti amonijeva acetata i ledene octene kiseline sintetizirana je serija 2-supstituiranih-4,5-difenil imidazola (1a-j). Strukture sintetiziranih spojeva potvrđene su IR, 1H NMR i masenom spektroskopijom. U testovima na anthelmintičko djelovanje određeno je vrijeme paralize 0,24 do 1,54 min i vrijeme smrti 0,39 do 4,40 min, dok standarni lijekovi albendazol i piperazin citrat imaju vrijeme paralize 0,54 i 0,58 min, a vrijeme smrti 2,16, odnosno 2,47 min pri istim koncentracijama (1 % m/V). Pet spojeva, 2-[2-hidroksifenil]-4,5-difenil imidazol (1b), 2-[3-metoksifenil]-4,5-difenil imidazol (1c), 2-[2-feniletenil]-4,5-difenil imidazol (1e), 2-[4-fluorofenil]-4,5-difenil imidazol (1g) i 2-[3-nitrofenil]-4,5-difenil imidazol (1h) pokazuju značajno anthelmintičko djelovanje u odnosnu na standardne lijekove

    Maternal hemodynamics in screen‐positive and screen‐negative women of the ASPRE trial

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    Objective To compare maternal hemodynamics and perinatal outcome, in pregnancies that do not develop pre‐eclampsia (PE) or deliver a small‐for‐gestational‐age (SGA) neonate, between those identified at 11–13 weeks' gestation as being screen positive or negative for preterm PE, by a combination of maternal factors, mean arterial pressure, uterine artery pulsatility index, serum placental growth factor and pregnancy associated plasma protein‐A. Methods This was a prospective longitudinal cohort study of maternal cardiovascular function, assessed using a bioreactance method, in women undergoing first‐trimester screening for PE. Maternal hemodynamics and perinatal outcome were compared between screen‐positive and screen‐negative women who did not have a medical comorbidity, did not develop PE or pregnancy‐induced hypertension and delivered at term a live neonate with birth weight between the 5th and 95th percentiles. A multilevel linear mixed‐effects model was used to compare the repeated measures of cardiac variables, controlling for maternal characteristics. Results The screen‐negative group (n = 926) had normal cardiac function changes across gestation, whereas the screen‐positive group (n = 170) demonstrated static or reduced cardiac output and stroke volume and higher mean arterial pressure and peripheral vascular resistance with advancing gestation. In the screen‐positive group, compared with screen‐negative women, birth‐weight Z‐score was shifted toward lower values, with prevalence of delivery of a neonate below the 35th, 30th or 25th percentile being about 70% higher, and the rate of operative delivery for fetal distress in labor also being higher. Conclusion Women who were screen positive for impaired placentation, even though they did not develop PE or deliver a SGA neonate, had pathological cardiac adaptation in pregnancy and increased risk of adverse perinatal outcome

    Set Theory and its Place in the Foundations of Mathematics:a new look at an old question

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    This paper reviews the claims of several main-stream candidates to be the foundations of mathematics, including set theory. The review concludes that at this level of mathematical knowledge it would be very unreasonable to settle with any one of these foundations and that the only reasonable choice is a pluralist one

    Mapping localized surface plasmons within silver nanocubes using cathodoluminescence hyperspectral imaging

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    Localized surface plasmons within silver nanocubes less than 50 nm in size are investigated using high resolution cathodoluminescence hyperspectral imaging. Multivariate statistical analysis of the multidimensional luminescence dataset allows both the identification of distinct spectral features in the emission and the mapping of their spatial distribution. These results show a 490 nm peak emitted from the cube faces, with shorter wavelength luminescence coming from the vertices and edges; this provides direct experimental confirmation of theoretical predictions

    Effect of high temperature and water stress on pollen germination and spikelet fertility in rice

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    In future climates, rice could more frequently be subjected to simultaneous high temperature and water stress during sensitive developmental stages such as flowering. In this study, five rice genotypes were exposed to high temperature, water stress and combined high temperature and water stress during flowering to quantify their response through spikelet fertility. Microscopic analyses revealed significant differences in anther dehiscence between treatments and genotypes, with a moderately high association with the number of germinated pollen grains on the stigma. There was a strong relationship between spikelet fertility and the number of germinated pollen on stigmas. Although, all three stress treatments resulted in spikelet sterility, high-temperature stress caused the highest sterility in all five genotypes. A cumulative linear decline in spikelet fertility with increasing duration of independent high-temperature stress and in combination with water stress was quantified. Better anther dehiscence, higher in vivo pollen germination, and higher spikelet fertility were observed in both the N22 accessions compared with IR64, Apo and Moroberekan under high temperature, water stress and combined stress, indicating its ability to tolerate multiple abiotic stresses

    Tetraspanin (TSP-17) Protects Dopaminergic Neurons against 6-OHDA-Induced Neurodegeneration in <i>C. elegans</i>

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    Parkinson's disease (PD), the second most prevalent neurodegenerative disease after Alzheimer's disease, is linked to the gradual loss of dopaminergic neurons in the substantia nigra. Disease loci causing hereditary forms of PD are known, but most cases are attributable to a combination of genetic and environmental risk factors. Increased incidence of PD is associated with rural living and pesticide exposure, and dopaminergic neurodegeneration can be triggered by neurotoxins such as 6-hydroxydopamine (6-OHDA). In C. elegans, this drug is taken up by the presynaptic dopamine reuptake transporter (DAT-1) and causes selective death of the eight dopaminergic neurons of the adult hermaphrodite. Using a forward genetic approach to find genes that protect against 6-OHDA-mediated neurodegeneration, we identified tsp-17, which encodes a member of the tetraspanin family of membrane proteins. We show that TSP-17 is expressed in dopaminergic neurons and provide genetic, pharmacological and biochemical evidence that it inhibits DAT-1, thus leading to increased 6-OHDA uptake in tsp-17 loss-of-function mutants. TSP-17 also protects against toxicity conferred by excessive intracellular dopamine. We provide genetic and biochemical evidence that TSP-17 acts partly via the DOP-2 dopamine receptor to negatively regulate DAT-1. tsp-17 mutants also have subtle behavioral phenotypes, some of which are conferred by aberrant dopamine signaling. Incubating mutant worms in liquid medium leads to swimming-induced paralysis. In the L1 larval stage, this phenotype is linked to lethality and cannot be rescued by a dop-3 null mutant. In contrast, mild paralysis occurring in the L4 larval stage is suppressed by dop-3, suggesting defects in dopaminergic signaling. In summary, we show that TSP-17 protects against neurodegeneration and has a role in modulating behaviors linked to dopamine signaling

    Spikelet Proteomic Response to Combined Water Deficit and Heat Stress in Rice (Oryza sativa cv. N22)

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    In future climates, rice crops will be frequently exposed to water deficit and heat stress at the most sensitive flowering stage, causing spikelet sterility and yield losses. Water deficit alone and in combination with heat stress significantly reduced peduncle elongation, trapping 32% and 55% of spikelets within the leaf sheath, respectively. Trapped spikelets had lower spikelet fertility (66% in control) than those exserted normally (>93%). Average weighted fertility of exserted spikelets was lowest with heat stress (35%) but higher with combined stress (44%), suggesting acquired thermo-tolerance when preceded by water-deficit stress. Proteins favoring pollen germination, i.e., pollen allergens and beta expansin, were highly upregulated with water deficit but were at normal levels under combined stress. The chaperonic heat shock transcripts and proteins were significantly up-regulated under combined stress compared with either heat or water deficit. The importance of spikelet proteins responsive to water deficit and heat stress to critical physiological processes during flowering is discussed

    Stimuli-Responsive Reversible Assembly of 2D and 3D Metallosupramolecular Architectures

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    The discovery of interconvertible platinum coordination modes, which reveals and masks cis coordinating groups upon addition of acid and base, respectively, has been exploited to facilitate stimuli-responsive assembly and disassembly of both two- and three-dimensional metallosupramolecular architectures. Treatment of a binclear platinum complex with acid along with ditopic and tritopic donor ligands generated a molecular square and a trigonal prism, respectively, in good to high yield. These complexes were unambiguously identified using electrospray mass spectrometry, H-1 NMR spectroscopy, and X-ray crystallography. Both assemblies can be disassembled into their constituent parts simply by treatment with base, and the prism can be cycled between the assembled and disassembled states by the alternate addition of acid and base.</p

    Characteristics of children with hip displacement in cerebral palsy

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    <p>Abstract</p> <p>Background</p> <p>Hip dislocation in children with cerebral palsy (CP) is a common and severe problem. The dislocation can be avoided, by screening and preventive treatment of children with hips at risk. The aim of this study was to analyse the characteristics of children with CP who develop hip displacement, in order to optimise a hip surveillance programme.</p> <p>Methods</p> <p>In a total population of children with CP a standardised clinical and radiological follow-up of the hips was carried out as a part of a hip prevention programme. The present study is based on 212 children followed until 9–16 years of age.</p> <p>Results</p> <p>Of the 212 children, 38 (18%) developed displacement with Migration Percentage (MP) >40% and further 19 (9%) MP between 33 and 39%. Mean age at first registration of hip displacement was 4 years, but some hips showed MP > 40% already at two years of age. The passive range of hip motion at the time of first registration of hip displacement did not differ significantly from the findings in hips without displacement.</p> <p>The risk of hip displacement varied according to CP-subtype, from 0% in children with pure ataxia to 79% in children with spastic tetraplegia. The risk of displacement (MP > 40%) was directly related to the level of gross motor function, classified according to the gross motor function classification system, GMFCS, from 0% in children in GMFCS level I to 64% in GMFCS level V.</p> <p>Conclusion</p> <p>Hip displacement in CP often occurs already at 2–3 years of age. Range of motion is a poor indicator of hips at risk. Thus early identification and early radiographic examination of children at risk is of great importance. The risk of hip displacement varies according to both CP-subtype and GMFCS. It is sometimes not possible to determine subtype before 4 years of age, and at present several definitions and classification systems are used. GMFCS is valid and reliable from 2 years of age, and it is internationally accepted.</p> <p>We recommend a hip surveillance programme for children with CP with radiographic examinations based on the child's age and GMFCS level.</p
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