251 research outputs found
ß-N-acetylglucosaminidase and ß-galactosidase from aleurone layers of resting wheat grains
No full textβ-N-acetylglucosamidase and β-galattosidase from aleurone layers of resting Wheat grains
No full textß-N-Acetylglucosaminidase and ß-Galactosidase from aleurone layer of resting wheat grains.
No full textWGA-binding hydrolases from the aleurone layers of resting wheat grains: Purification and characterization of the WGA-binding ß-N-acetylglucosaminidase.
No full textThe Mechanochemical Beckmann Rearrangement: An Eco-efficient "cut-and-Paste" Strategy to Design the "good Old Amide Bond"
No full textDiscovered over a century ago, Beckmann rearrangement is still today fully compliant with all the green chemistry principles and consistent with the key aspects of sustainable development. Herein, we report on a sustainable mechanochemical procedure allowing the design of new amide frameworks via an eco-efficient "cut-and-paste"process of C-C and C-N bonds on the oxime backbone. We combined inexpensive and readily available reagents, such as p-tosyl imidazole (p-Ts-Im) and oxalic acid, to prepare smoothly and in good to high yields a library of structurally different amides, including value-added marketed compounds such as ε-caprolactam and the active pharmaceutical ingredient (API) paracetamol. This solvent-free mechanochemical procedure has also been optimized and successfully extended to several ketones serving as oxime precursors
Misfolding of the amyloid beta-protein: A molecular dynamics study
No full textAmyloid beta-proteins spontaneously aggregate and build plaques in the
brains of Alzheimer's disease patients. The polypeptide has been the
subject of extensive in vitro and computational research. Still, the
pathway to aggregational forms and their exact conformations remain
largely unclear. Here we present an extensive molecular dynamics
approach simulating the protein in various temperatures, pH conditions,
and with different charge states of the N- and C-termini, thus exploring
the conformational space of the protein at large. Our results show that
the protein is able to sample different conformations, many of which are
rich in beta structure content, and all characterized by a rapid loss of
helix 1 that converts into a pi-helix, while helix 2 samples random and
beta-rich structures. Moreover, a hydrophobic cluster is observed
involving Val18, Phe19, Ala21, and Gly25. The results are carefully
compared with recent NMR and spectroscopic data, and are in global
agreement with the experimental findings
Applications of bio-feedback to muscle models
No full textAn EMG-driven musculoskeletal model is implemented to estimate subject-specific musculoskeletal parameters such as the optimal physiological muscle length, the tendon slack length and the maximum isometric muscle force of flexor and extensor muscle groups crossing the wrist, as well as biomechanical indexes to quantify the muscle operating range, the stiffness of the musculotendon actuators, and the contribution of the muscle fibers to the joint moment. Twelve healthy subjects (11 males and 1 female, mean age 31.1 ± 8.7 years) were instructed to perform isometric maximum voluntary contractions of wrist flexors and extensors. Recorded EMGs were used as input to the model and the root mean square error (RMSE) between measured and predicted torque was minimised to estimate the subject-specific musculotendon parameters. The model was validated and the RMSE and the normalised RMSE calculated during estimation and validation phases are compared. Estimated subject-specific musculoskeletal parameters vary in a physiologically realistic range, while the biomechanical indexes are consistent with previously published data. The proposed methodology proved to be effective for the in-vivo estimation of physiological parameters of the musculotendon complex and has potential as an investigative tool to distinguish aetiological differences among subjects affected by musculoskeletal disorder
Solvent-free synthesis of nitrones in a ball-mill
No full textVarious C-aryl and C-alkyl-nitrones were synthesized within 0.5–2 h via condensation of an equimolar amount of aldehydes and N-substituted-hydroxylamines under solvent-free conditions in a ball-mill apparatus. Reactions can be performed without the need of excluding air and moisture and yields the expected products with no need for further purification. The study has been complemented by Differential Scanning Calorimetry (DSC) and solid-state 13C MAS nuclear magnetic resonance experiments. We have also studied the temperature profile during the reaction. A comparative study with the corresponding solvent-free microwave activated reaction showed the superiority of the ball-milling method; 31 examples are described, including the synthesis of the anti-aging agent C-phenyl-N-tert-butyl nitrone (PBN) and one of its analogues C-2-pyridyl-N-tert-butylnitrone (2-PyB
The archaeology of ancient pastoral sites in the territory of Montescaglioso (4th - 1st century BC). An interdisciplinary approach from the Bradano valley (Basilicata - southern Italy)
No full textThis paper discusses a complete set of hoplite armour (panoply), found in tomb 672 at Chiaromonte (Basilicata),
consisting of a “Corinthian” helmet, front and back greaves, bronze protection for the left forearm, and an iron sword. The tomb group can be compared to other tombs with panpolies at Chiaromonte, datable to the 6th century BC on the basis of other contexts in the region containing “Corinthian” helmets. Furthermore, the archaeological evidence from Chiaromonte is used to contextualize this important indigenous settlement centre against the backdrop of the “North- Lucanian” and the “Oinotrian” cultures. Finally, 6th-century Chiaromonte is related to the political and military system of Sybaris, mentioned by ancient sources, but so far scarcely attested “on the ground.” The author argues that the elite of Chiaromonte served in the cavalry of Sybaris
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