Search results for "reduction"

Increased susceptibility of ribulose-1,5-bisphosphate carboxylase/oxygenase to proteolytic degradation caused by oxidative treatments

1990

The susceptibility of the chloroplastic enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase to proteolysis by trypsin, chymotrypsin, proteinase K, and papain is enhanced by oxidative treatments including spontaneous oxidation of cysteines. Proteinases exhibit a high specificity for the oxidized inactive form of the carboxylase, cleaving its large subunit. Treatment of the inactive enzyme with dithiothreitol results in partial recovery of both carboxylase activity and resistance to proteolysis. This behavior may explain the specific degradation of ribulose-1,5-bisphosphate carboxylase/oxygenase that occurs in vivo during leaf senescence.

Assessing Non-Photosynthetic Cropland Biomass from Spaceborne Hyperspectral Imagery

2021

Non-photosynthetic vegetation (NPV) biomass has been identified as a priority variable for upcoming spaceborne imaging spectroscopy missions, calling for a quantitative estimation of lignocellulosic plant material as opposed to the sole indication of surface coverage. Therefore, we propose a hybrid model for the retrieval of non-photosynthetic cropland biomass. The workflow included coupling the leaf optical model PROSPECT-PRO with the canopy reflectance model 4SAIL, which allowed us to simulate NPV biomass from carbon-based constituents (CBC) and leaf area index (LAI). PROSAIL-PRO provided a training database for a Gaussian process regression (GPR) algorithm, simulating a wide range of non…

Data-driven analysis for fMRI during naturalistic music listening

2017

Interest towards higher ecological validity in functional magnetic resonance imaging (fMRI) experiments has been steadily growing since the turn of millennium. The trend is reflected in increasing amount of naturalistic experiments, where participants are exposed to the real-world complex stimulus and/or cognitive tasks such as watching movie, playing video games, or listening to music. Multifaceted stimuli forming parallel streams of input information, combined with reduced control over experimental variables introduces number of methodological challenges associated with isolating brain responses to individual events. This exploratory work demonstrated some of those methodological challeng…

Low-Dimensional Representations of Earth System Processes

2020

In times of global change, we must closely monitor the state of our planet in order to understand gradual or abrupt changes early on. In fact, each of the Earth's subsystems-i.e. the biosphere, atmosphere, hydrosphere, cryosphere, and anthroposphere-can be analyzed from a multitude of data streams. However, since it is very hard to jointly interpret multiple monitoring data streams in parallel, one often aims for some summarizing indicator. Climate indices, for example, summarize the state of atmospheric circulation in a region, e.g. the Multivariate ENSO (El Ñino-Southern Oscillation) Index. Indicator approaches have been used extensively to describe socioeconomic data too, and a range of …

Influence of the functionalisation of mesoporous silica material UVM-7 on polyphenol oxidase enzyme capture and enzymatic browning

2020

Polyphenol oxidase (PPO), also known as tyrosinase and catechol oxidase, is the enzyme responsible for enzymatic browning in foods. It causes undesirable organoleptic, nutritional and colour changes. Here, we report the preparation of five nanomaterials and a study of their ability to modulate PPO enzyme activity. The materials consist of UVM-7 supports (a mesoporous silica material) modified with diverse functional groups (i.e. amine, carboxylic acid, isocyanate, alkane and pyridine). We also studied the PPO immobilisation capability of the materials. All the materials, except the carboxylic acid functionalised one, offer high PPO loading capabilities and the immobilisation speed increases…

Applicazione di trasformate wavelet per la riduzione del rumore nelle immagini NMR di rocce sedimentarie

2007

Il sempre crescente interesse verso i Beni Culturali suscita molteplici problematiche inerenti la salvaguardia e la diagnosi del loro stato di conservazione. In questo ambito, lo studio delle caratteristiche, quali ad esempio le proprietà capillari delle rocce sedimentarie, ricopre un’importanza cruciale non solo per studiare lo stato di conservazione ma anche per fornire utili indicazioni sulle possibili tecniche e sui materiali da utilizzare negli eventuali trattamenti di protezione e restauro. Al fine di ottenere approfondite informazioni sulle proprietà capillari, il presente lavoro propone un metodo matematico utile nello studio della cinetica di assorbimento capillare. Lo studio è sta…

Multi-Functional Nanogels for Tumor Targeting and Redox-Sensitive Drug and siRNA Delivery

2016

(1) Background: A new family of nanosystems able to discern between normal and tumor cells and to release a therapeutic agent in controlled way were synthetized by e-beam irradiation. This technique permits to obtain biocompatible, sterile, carboxyl-functionalized polyvinylpyrrolidone (PVP-co-acrylic acid) nanogels (NGs); (2) Methods: Here, we performed a targeting strategy based on the recognition of over-expressed proteins on tumor cells, like the folate receptor. The selective targeting was demonstrated by co-culture studies and flow cytometry analysis, using folate conjugated NGs. Moreover, nanoparticles were conjugated to a chemotherapeutic drug or to a pro-apoptotic siRNA through a gl…

Computational Investigation of Alkynols and Alkyndiols Hydrogenation on a Palladium Cluster

2013

The reaction path leading to the partial and total reduction of alkynols and alkyndiols with general formula R–CH2–C≡C–CH(OH)–R′ and R–CH(OH)–C≡C–CH(OH)–R′ (R, R′ = H, CH3) on a D3h symmetry Pd9 cl...

Development of conservation methods for the restoration of paper materials

Paper, one of the most common materials of Cultural Heritage, undergoes serious deterioration caused by physical, chemical and biological factors. One of the main causes of deterioration is the acidic and/or oxidative environment. The studies of deterioration and conservation of paper have been increasing and require further development of methods and treatments that can stabilize and strengthen the paper. Various conservation treatments are being applied to model and to historical paper by using different chemicals methods. Their effectiveness for conservation and restoration are under study. Internal and external factors degrade the paper by promoting various reaction pathways. The two mo…

Drawing and extruding: Theoretical and approximate formulas

1969

The problem of drawing of wires and of strips has been treated in several studies; among these the studies of Sachs seem essential. However, the results deduced according to similar theories are not always in accordance with the experimental results: reduction of area or of thickness are in fact usually smaller than those resulting from the theory. This is in dependance of the fact that Sachs has adopted the Limiting Condition of Yielding by v. Mises, according to which the limit values of stress in traction and compression are equal. More recently other AA. (Alberti, Noto La Diega, Bugini), admitting the Limiting Condition of Yielding by A. (or of the Paraboloid of Revolution) of which we …