1,721,005 research outputs found
Humic substances and uses thereof in agro-environment
No full textThe present invention relates to the two main categories of humic substances, humic acids and fulvic acids and their use for hindering the propagation and/or contamination with prion infectivity both in agricultural and environmental systems
Humic substances and therapeutic uses thereof
No full textThe present invention relates to the medical field, in particular to the use of natural organic polyanions, i.e. humic substances, HSs, in the treatment of neurodegenerative diseases, such as Prion disease, Alzheimer's and Parkinson's disease
ALTERNATIVE METHOD FOR CARBOXYL GROUP DETERMINATION IN HUMIC SUBSTANCES
No full textA new precipitation titration method, employing cetyltrimethylammonium (CTA+), is proposed for analysis of carboxyl groups of humic substances in solution. The method was tested with polyphenol-polycarboxylic acids standard solutions: recovery factors ranged from 0.94 to 1.09. Results obtained by performing precipitation of humic acids samples at pH = 9.8 and at 7.0 are compared with those obtained by the Ca-acetate method. The difference between the number of COOH per unit weight of humic preparation calculated by precipitation with CTA+ at pH = 7.0 and by the Ca-acetate exchange reaction ranged between 1 and 45%. In most samples overestimation of COOH groups by the Ca-acetate method appears to be higher than the mean relative error of the CTA+ precipitation method (5%). Key words: Carboxylic group determination, humic substances, cetyltrimethylammoniu
Investigation of the intereactions between humic substances and a cationic detergent
No full textVisible spectrophotometric measurements were used to study binding of cetltrimethylammonium to humic molecules. Detergent molecules appeared to bind to ionized carboxyl and phenolic groups. Complete neutralization of negative charges caused quantitative precipitation of humic substances at low ionic strength. Detergent amounts higher than the stoichiometric ratio caused salting in of precipitate. The influence of organic carbon concentration, ionic strength and pH of the solution on the complex composition at minimum solubility was investigated
Distribution of cadmium and induced Cd-binding proteins in roots, stems and leaves of Phaseolus vulgaris
No full textRoots, stems and leaves of Phaseolus vulgaris L. (cv. Rubino PF1H) grown in Hoagland's solution supplemented with 1, 2 and 2.5 mM Cd(NO3)2 were analyzed. In comparison with control plants grown in a nutrient solution containing equivalent amounts of NO3- added as KNO3, plants grown in the presence of 1 mM Cd(NO3)2 showed a significant decrease in fresh weight and per cent dry matter in roots, whereas stems were slightly affected and leaves not at all. At 2 and 2.5 mM Cd concentrations the fresh weight of roots was unaffected, but their dry matter content was strongly reduced; stems showed significant, even limited decrease of both fresh weight and % dry matter. In comparison, the fresh weight and foliar area of leaves were strongly reduced, the dry matter content being unaffected. The distribution of Cd in plant tissues showed that total Cd in roots exceeded by about one and two orders of magnitude total Cd of stems and leaves, respectively. Intercellular spaces of plant tissues were washed successively with water, 5 mM CaCl2 and 5 mM EDTA. Results showed that most of Cd in the apoplast of root, stem and leaf tissues was extractable by complexing it with EDTA. Water extractable Cd in intercellular spaces was present in ionic form, as Cd2+. Gel filtration of tissue extracts showed that 83.4% of total Cd was present as free metal ion in extract of leaves, whereas 56.6% and 48.7% was found in stem and roots extracts, respectively. The remaining part of the total Cd was associated with protein fractions. One type of Cd-protein fraction of about 10 kDa molecular weight (Kav 0.54) was present in roots, stems and leaves, binding 24.1%, 43.4% and 16.6% of total Cd, respectively. A second protein fraction with apparent mol. wt. > 30 kDa was present only in roots, binding 27.2% of total root Cd. This result was confirmed by SDS-PAGE electrophoresis, showing a Cd-induced protein band common to leaves, stems and roots with an apparent mol. wt. 9.2 kDa, which can be interpreted as phytochelatins, and an intensively stained Cd-induced band, present only in root extracts, of about 42 kDa apparent mol. wt. © 1991
Fanghi" in agricoltura, risorsa troppo spesso dimenticata
No full textSolamente pochi agricoltori potrebbero essere a conoscenza del significato del termine perugino,
de\la sua origine e del rispetto con cui, ancor oggi, ìe
persone anziane di Lucca e provincia ne fanno memoria.
ll termine perugino designa il contenuto del pozzo nero ed è
stato coniato secoli fa per indicare l'attività di una cooperativa di imprenditori originari di Perugia periodicamente impegnata a svuotare i pozzineri di tutta la città. Tale attività prevedeva il solo e rìconosciuto
compenso da parte degli agricoltori che ne richiedevano
f impiego come concime, usato del resto per
ferúbzzare i campi fin dall'origine della storia dell'uomo.
In Italia forse l'esempio di utilizz azione megl io or ganizzata
dei pozzineri si è avuta nelle marcite, vere e proprie
opere di ingegneria idraulica della bassa milanese. Molti ricorderanno che ancora nella seconda metà del secolo scorso le fogne venivano scaricate nelle campagne e andavano a lambire Ie superfici del terreno, sistemate in modo da agevolare un loro lento scorrimento e l'assorbimento di ciò che convogliavano. Da Melegnano
in giù la gente si lamentava bofonchiando che
"A MiIàn gh'en i cèss, a Melegnàn i udùr" (a Milano ci sono
i cessi, a Melegnano gli odori), ma gli effetti mirabili di tale
pratica erano più che evidenti: il fieno che si raccoglieva
nella pianura padana era costituito da d ue o tre tagli (maggengo,agostano e quando andava bene anche un rachitico terzuolo), mentre in tutta la bassa milanese e nell'attuale provincia di Lodi se ne contavano
sette o otto o anche di più, fino a undici o dodici, e di ottima qualita'. L'articolo esamina questi aspetti
Soil humic substances hinder the propagation of prions
Full text linkPrions are infectious pathogens causing fatal neurodegenerative disorders, known as transmissible spongiform encephalopathies (TSEs), or prion diseases, which affect different mammalian species. TSEs include scrapie in sheep, bovine spongiform encephalopathy (BSE) in cattle, chronic wasting disease (CWD) in mule deer, elk, and moose (cervids), and Creutzfeldt-Jakob disease (CJD) in humans. The prominent, if not only, component of prions is a misfolded conformer (PrPSc) of a constitutive sialoglycoprotein, the cellular prion protein (PrPC). A notable feature of prion diseases is horizontal transmission between grazing animals, implying that contaminated soil may serve to propagate the disease. In this respect, it has been reported that grazing animals ingest from tens to hundreds grams of soil per day, either incidentally through the diet, or deliberately in answering salt needs, and that mule deer can develop CWD after grazing in locations that previously housed infected ..
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