953 resultados para Alchornea glandulosa extract


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Metsäteollisuudesta kertyy vuosittain suuria määriä ylijäämämateriaalia, kuten puun kuorta ja oksia.Ylimääräinen aines käytetään pääasiassa energiantuotantoon, mutta uusia soveltamismahdollisuuksia kaivataan. Kuoren on havaittu olevan potentiaalinen lähde monille bioaktiivisille yhdisteille, joille olisi käyttöä esimerkiksi lääke- ja kemianteollisuudessa sekä maa-, metsä- ja puutarhatuotannon tuholaistorjunnassa. Tutkimus on osa Euroopan Unionin rahoittamaa ForestSpeCs-projektia, jonka tarkoituksena on selvittää metsäteollisuuden ylijäämämateriaalien vaihtoehtoisia käyttötapoja. Valittujen kymmenen teollisesti merkittävän pohjoisen puulajin (Abies nephrolepis, Betula pendula, Larix decidua, L. gmelinii, L. sibirica, Picea abies, P. ajanensis, P. pumila, Pinus sylvestris, Populus tremula) kuoresta uutettujen aineiden soveltuvuutta syönninestoaineeksi testattiin kaaliperhosen (Pieris brassicae L.) ja krysanteemiyökkösen (Spodoptera littoralis Boisduval) toukilla sekä osittain sinappikuoriaisella (Phaedon cochloreae Fabricius) ja idänlehtikuoriaisella (Agelastica alni L.). Uutteet valmistettiin yhteistyössä projektin ryhmien avulla tai itsenäisesti erilaisin menetelmin. Testaukset tehtiin laboratorio-oloissa käyttäen lehtikiekkojen valintabiotestiä sekä karkeilla uutteilla että niistä erotelluilla yksittäisillä yhdisteillä. Tehdyistä mittauksista laskettiin syönninestoindeksit (FDI). Tulosten perusteella lähes kaikki testatut uutteet vaikuttivat ainakin jossain määrin kohdehyönteisen syöntikäyttäytymiseen. Hieman yli puolet kaaliperhosella testatuista 46 uutteesta aiheuttivat yli 50 % syönnineston eli kaaliperhonen suosi kontrollilehtiä uutteella käsiteltyjä todennäköisemmin. Krysanteemiyökkösellä yli 50 %:n syönnineston aiheuttivat vain seitsemän testatuista 56 uutteesta. Lisäksi kolme uutetta lisäsi käsiteltyjen kiekkojen syöntiä merkittävästi. Idänlehtikuoriaistoukat ja -aikuiset karttoivat erityisesti abietiinihapolla käsiteltyjä lehtiä. Sinappikuoriaisella testatut uutteet toimivat myös lupaavasti. Testattujen puulajien kuoresta on mahdollista uuttaa biologisesti aktiivisia yhdisteitä, mutta tuholaistorjunnan kannalta oikeiden pitoisuuksien ja tehokkaiden uuttomenetelmien löytäminen vaatii jatkotutkimuksia. Kuoren sisältämien yhdisteiden laatu ja määrä vaihtelevat monien tekijöiden, kuten ympäristön ja genetiikan vaikutuksesta. Hyönteisten sietokyky vaihtelee myös paljon lajeittain ja yksilöidenkin välillä on eroja. Uutteista valmistettavia torjunta-aineita olisi kuitenkin mahdollista sisällyttää esimerkiksi integroituun torjuntaan muiden menetelmien rinnalle tulevaisuudessa.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The development of a radioreceptor assay (RRA) that can measure serum LH in a variety of species and CG in sera and urine of pregnant women and monkeys is reported. Using sheep luteal membrane as the receptor source and I-125-labelled hLH/hCG as the tracer, dose-response (displacement) curves were obtained using hLH or hCG as standard. The addition of LH-free serum (200 mul per tube) had no affect on the standard displacement curve. The assay is simple, requires less than 90 min to complete and provides reproducible results. The sensitivity of the assay was 0.6 ng hLH per tube and the intra- and interassay variations were 9.6 and 9.8, respectively. Sera obtained from male and female bonnet monkeys (Macaca radiata) and monkey pituitary extract showed parallelism to the standard curve. The concentrations of LH measured correlated with the physiological status of the animals. Sera of rats, rabbits, hamsters, guinea-pigs, sheep and humans showed parallelism to the hLH standard curve indicating the viability of the RRA to measure serum LH of different species. Since the receptors recognize LH and CG, detection of pregnancy in monkeys and women was possible using this assay. The sensitivity of the assay for hCG was 8.7 miu per tube. This RRA could be a convenient alternative to the Leydig cell bioassay for obtaining the LH bioactivity profile of sera and biological fluids.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

After ensilation, the toxic Compositae weed Parthenium hysterophorus was devoid of the toxic principle parthenin. Laboratory-scale ensilation indicated that no parthenin was detectable after 5 wk of anaerobic fermentation. For animal feeding studies, silage was made on a large scale from Parthenium mixed with maize or from Parthenium alone. Crossbred bull and buffalo bull calves were fed diets containing the silages, or control diet without silage, for 12 wk. The animals consumed both silages with relish, and body weight gains of silage-fed calves did not differ from those of the controls. The digestibilities of dry matter, fibre and nitrogen-free extract were greater with the control diet, but the biological value of proteins tended to be greater with the silage-containing diets. Haematological studies indicated no significant differences between experimental and control groups in selected parameters, except for a reduction in blood urea nitrogen in the animals fed silage. The possible causes for these biochemical alterations are discussed. Since the nutritive value of Parthenium silage compares favourably with the standard diet, and Parthenium seeds collected from the silage did not germinate, we suggest that ensilation can be used as an additional method in the containment and eradication of these plants, which grow wild in India.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A novel approach to estimate fringe order in Moire topography is proposed. Along with the light source used to create shadow of the grating on the object (as in conventional moire), proposed method uses a second light source which illuminates the object with color bands from the side. Width of each colored band is set to match that height which leads to a 2 pi phase shift in moire fringes. This facilitates one to rule the object with colored bands, which can be used to estimate fringe order using a color camera with relatively low spatial resolution with out any compromise in height sensitivity. Current proposal facilitates one to extract 3D profile of objects with surface discontinuities. It also deals with the possible usage of moire topography (when combined with the proposed method) in extracting 3D surface profile of many objects with height discontinuities using a single 2D image. Present article deals with theory and simulations of this novel side illumination based approach.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Cell-free extracts with high 14?-hydroxylase activity were prepared from induced vegetative cell cultures of Mucor piriformis by grinding in potassium phosphate buffer (0.05 M, pH 8.0) containing glucose (0.25 M), KCl (1 mM), glutathione (1.0 mM) and glycerol (10%). Although the ideal pH for preparing the cell-free extract from vegetative cells was 8.0, the pH optimum of the hydroxylase was found to be 7.6. Microsomes (2.0 mg) prepared from the crude cell-free extract hydroxylated progesterone to 14?-hydroxyprogesterone in not, vert, similar60% yields in 30 min in the presence of NADPH and O2. Microsomes prepared from the uninduced cells did not contain any 14?-hydroxylase activity. The hydroxylase activity was inhibited to a significant extent by CO and p-chloromercuribenzoate whereas moderate inhibition was noticed in the presence of SKF-525A, metyrapone and N-methylmaleimideindicating the possible involvement of the cytochromeP-450 system in the reaction. The membrane bound hydroxylase was solubilized using Triton X-100 and the solubilized fraction contained nearly 35% of the original hydroxylase activity.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Objective: The present study is to evaluate the antiulcer effect of hydroalcoholic (70%) extract of Terminalia chebula fruit. Materials and methods: Aspirin, ethanol and cold restraint stress-induced ulcer methods in rats were used for the study. The effects of the extract on gastric secretions, pH, total and free acidity using pylorus ligated methods were also evaluated. Results: Animals pretreated with doses of 200 and 500 mg/kg hydroalcoholic extract showed significant reduction in lesion index, total affected area and percentage of lesion in comparison with control group (P < 0.05 and P < 0.01) in the aspirin, ethanol and cold restraint stress-induced ulcer models. Similarly extracts increased mucus production in aspirin and ethanol-induced ulcer models. At doses of 200 and 500 mg/kg of T. chebula extract showed antisecretory activity in pylorus ligated model, which lead to a reduction in the gastric juice volume, free acidity, total acidity, and significantly increased gastric pH. Discussion and conclusion: These findings indicate that hydroalcoholic extract of the fruit T. chebula displays potential antiulcerogenic activity. This activity thus lends pharmacological credence to the suggested use of the plant as a natural remedy in the treatment or management of ulcer.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

We have developed a theory for an electrochemical way of measuring the statistical properties of a nonfractally rough electrode. We obtained the expression for the current transient on a rough electrode which shows three times regions: short and long time limits and the transition region between them. The expressions for these time ranges are exploited to extract morphological information about the surface roughness. In the short and long time regimes, we extract information regarding various morphological features like the roughness factor, average roughness, curvature, correlation length, dimensionality of roughness, and polynomial approximation for the correlation function. The formulas for the surface structure factors (the measure of surface roughness) of rough surfaces in terms of measured reversible and diffusion-limited current transients are also obtained. Finally, we explore the feasibility of making such measurements.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A geometrically polar granular rod confined in 2D geometry, subjected to a sinusoidal vertical oscillation, undergoes noisy self-propulsion in a direction determined by its polarity. When surrounded by a medium of crystalline spherical beads, it displays substantial negative fluctuations in its velocity. We find that the large-deviation function (LDF) for the normalized velocity is strongly non-Gaussian with a kink at zero velocity, and that the antisymmetric part of the LDF is linear, resembling the fluctuation relation known for entropy production, even when the velocity distribution is clearly non-Gaussian. We extract an analogue of the phase-space contraction rate and find that it compares well with an independent estimate based on the persistence of forward and reverse velocities.