156,433 research outputs found

    Phytotherapy of chlorophyllin exposed Lymnaea acuminata: A new biotechnological tool for fasciolosis control

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    AbstractPhytotherapy of chlorophyllin formulations against Fasciola gigantica infected Lymnaea acuminata under sunlight exposure was highly toxic against redia and cercaria larvae. Binary combinations (1:1 ratio) of chlorophyllin (CHL)+freeze dried cow urine (FCU) were more toxic against cercariae (8h LC50: 9.6mgL−1) than single treatment with chlorophyllin (8h LC50: 12.6mgL−1) in sunlight. The larvicidal activity of sunlight exposed CHL against rediae (8h LC50: 13.5mgL−1) and cercariae (8h LC50: 12.6mgL−1) was more pronounced than laboratory conditions CHL treatment (rediae- 8h LC50: 305.9mgL−1; cercariae- 8h LC50: 765.4mgL−1). Larvicidal activity of FCU was less than CHL and CHL+FCU against both redia and cercaria. Chlorophyllin and its formulations were more toxic against redia and cercaria larvae in sunlight than laboratory conditions. CHL and its different formulations may be used as potent larvicides against Fasciola gigantica larvae. Chlorophyllin formulations will be economical, ecologically sounder and their use in aquatic environment will be safe

    Dependence of spontaneous polarization on stacking sequence in SiC revealed by local Schottky barrier height variations over a partially formed 8H-SiC layer on a 4H-SiC substrate

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    Ballistic electron emission microscopy was used to measure the increase of local Schottky barrier (compared to the surrounding 4H-SiC area) over a partial 8H-SiC layer that is the surface-exposed tail of an 8H stacking fault inclusion extending from 4H substrate. This local increase is believed to be due to polarization charge induced at the interface of partial 8H layer and underlying 4H host, resulting from the spontaneous polarization (SP) difference between SiC regions with different bilayer stacking. This is a direct experimental probe of the dependence of SP in SiC on local stacking sequence by measuring carrier transport.open1

    Secondary sulfonamides as effective lactoperoxidase inhibitors

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    Secondary sulfonamides (4a–8h) incorporating acetoxybenzamide, triacetoxybenzamide, hydroxybenzamide, and trihydroxybenzamide and possessing thiazole, pyrimidine, pyridine, isoxazole and thiadiazole groups were synthesized. Lactoperoxidase (LPO, E.C.1.11.1.7), as a natural antibacterial agent, is a peroxidase enzyme secreted from salivary, mammary, and other mucosal glands. In the present study, the in vitro inhibitory effects of some secondary sulfonamide derivatives (4a–8h) were examined against LPO. The obtained results reveal that secondary sulfonamide derivatives (4a–8h) are effective LPO inhibitors. The Ki values of secondary sulfonamide derivatives (4a–8h) were found in the range of 1.096 × 10−3 to 1203.83 µM against LPO. However, the most effective inhibition was found for N-(sulfathiazole)-3,4,5-triacetoxybenzamide (6a), with Ki values of 1.096 × 10−3 ± 0.471 × 10−3 µM as non-competitive inhibition

    Relative expression of CRy10 in GM cotton lines resistant to boll weevil.

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    Boll weevil (Anthonomus grandis) is a serious pest of cotton crop in several parts of world. The control is done by synthetic pesticides that increase the management costs. Embrapa coordinates an important research involving development of GM cotton resistant to boll weevil, by genetic transformation. Seven line (T0-8H) containing a Btcry 10 have been identified by feeding bioassays and ELISA, which showed reasonable toxicity against adult boll weevils. In this work, these lines were used in order to estimate the presence and relative expression of cry 10 by PCR and RT-qPCR, respectively, from young buds of 50d-plants. RT-qPCR assays were performed, by using Syber Green Rox Plus Master Mix 2X (LGC). Three endogenous cotton gene (GhACT, GhUBQ14 and GhPP2A) were used as a standard control. At first, 95°C/15 min and 40 cycles of 95°C/ 20 sec, 60°C/ 20 sec and 72°C/ 20 sec. Then, a curve of denaturation (melting curve) was performed after conclusion of amplification, at 95°C/15 sec, 60°C/15 sec, rising 2°/min until reaching 95°C. All reactions were carried out with experimental and biological replications. The threshold cycle (Ct) and PCR efficiency was estimated by Real-time PCR Miner program. The analyses were performed by using qBASEPlus program. Graphics, Cqs and Melt curve were automatically generated, based on the normalization method with a reference gene, ??Cq. Varied levels of expression were found in GM lines, too low in 8H-269 and 8H-357, mid in 8H-282 and 8H-346 and high in 8H- 336 (14x). These data agreed with previous results obtained by ELISA assays. Eleven lines derivate from 8H-336 (T1) were analyzed by PCR assays with genomic DNA, using 2 primer combinations. More than 50% showed amplicons confirming the presence of gene in selected lines. Taking in account that a reasonable level of resistance should overcoming 2 ug of protein/g tissue, we suggested that 8H-366 is the best genotype for control the cotton boll weevil. This material will be further advanced for entomological assays with larvae and adults of boll weevil

    The redeeming features of reaction of the 8-formyl-7-hydroxychromones with malononitrile

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    A range of 4H,8H-pyrano[2,3-f]chromen-4,8-diones have been prepared using Knoevenagel reaction of the 8-formyl-7-hydroxychromones with malononitrile. The 4H,8H-pyrano[2,3-f]chromen-4,8-dione derivative was also obtained through the acid hydrolysis of the 8-imino-4H,8H-pyrano[2,3-f]chromen-4-one. 8-Formyl-7-hydroxychromone 1 was found to add two molecules of malononitrile through Michael addition resulting in formation of the 2-[8-amino-3-(4-chlorophenyl)-9-cyano-2-methyl-4-oxo-4H,10H-pyrano[2,3-f]chromen-10-yl]malononitrile. Supplementary information (CIF file

    Ecofisiologia da germinação de Lavandula luisieri (Roseira) Rivaz-Martínez

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    A capacidade germinativa de Lavandula luisieri (Rozeira) Rivas-Martínez, espécie endémica da Península Ibérica, pertencente à família Lamiaceae, cujos diásporos foram colhidas em quatro locais da Beira Interior-Portugal (Casal da Fraga, Mata, Penamacor e Vila Velha de Ródão), foi avaliada durante dois anos. Sementes conservadas durante diferentes tempos após colheita, foram ensaiadas em condições controladas de temperatura e luz. As modalidades seleccionadas foram: para um tempo de conservação de 40 dias a temperatura contínua de 25ºC e fotoperíodo de 16h e para a alternância de 8º/18ºC o fotoperíodo de 8h que coincidiu com a temperatura mais elevada; para um tempo de conservação de 75 dias, a temperatura contínua de 25ºC e os fotoperíodos de 8h e 16h; para um tempo de conservação de 110 dias a alternância de 8º/18ºC e fotoperíodo de 8h; para um tempo de conservação de 288 dias, a alternância de 8º/18ºC e fotoperíodo de 8h e a temperatura contínua de 25ºC e um fotoperíodo de 16h. Os resultados confirmam que as condições de Outono (temperaturas alternas de 8º/18ªC ) foram as mais adequadas para a germinação desta espécie durante os diferentes tempos de conservação

    Diol-Mediated versus Water-Mediated Proton Transfer Reactions

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    The triple-proton-transfer reactions of 8H-1,8-naphthyridin-2-one (8H-naph) have been investigated by employing different ab initio quantum mechanical methods. The proton transfer reactions studied were facilitated through an adjacent 1,3-propanediol molecule or two adjacent water molecules. Identical proton transfer reactions were studied using a model system of 8H-naph to investigate the validity of computational approaches that use model systems to study more complex systems. The solvent effects on the structures were investigated for comparison to the initial gas phase calculations. The potential energy, reaction force, and work profiles were studied along the intrinsic reaction coordinate to monitor the developing proton transfer reactions

    Prolongation of the Intestinal Viability Using Oxygenated Perfluorocarbon in an Experimental Model of Acute Intestinal Ischemia

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    AbstractObjectivesLiquid perfluorocarbons (PFCs) are well known for their capability to carry respiratory gases. The aim of this study was to evaluate the effectiveness of oxygenated F-Decalin on the intestinal viability, in an experimental model of acute intestinal ischemia.Material and MethodsThirty-six rabbits were subjected to 8h intestinal ischemia by ligation of the superior mesenteric artery (subgroups 1), the mesenteric vein (subgroups 2) or both vessels (subgroups 3). The animals were divided into three groups: (a) Control (ischemia alone), (b) PFC-O2 (ischemia plus infusion of oxygenated F-Decalin) and (c) PFC (ischemia plus infusion of not-oxygenated F-Decalin). Intestinal biopsies from four different sites and blood samples for serum enzymes measurements were taken at 2, 4, 6 and 8h. All tissue sections were examined blindly under light microscope. Sections from the specimens were taken at 4 and 8h, and examined blindly under the electron microscope. Statistical analysis was performed by non-parametric Kruskal Wallis test.ResultsUsing light microscope, the observed intestinal damages to the sections from Control and PFC groups were severe at 4h and destructive after 8h. On the contrary, minimal injuries were observed in the biopsies from PFC-O2 group at 4 and even after 8h of ischemia. These findings were confirmed by the electron microscope study and correlated to the serum enzymes measurements.ConclusionsThese results suggest that intestinal viability could be prolonged after acute ischemia using oxygenated perfluorocarbons and this could be a promising pretreatment modality for a variety of mesenteric ischemic forms
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