857 research outputs found
Improvement in Wear Resistance of Grade 37 Titanium by Microwave Plasma Oxy-Carburizing
Grade 37 titanium is widely used in racing applications thanks to its oxidation resistance up to 650 °C, but it suffers from poor wear and fretting resistance, especially at high temperature. In this paper, different surface modification techniques, namely, carburizing, coating by PVD-ZrO2 and a novel microwave plasma oxy-carburizing treatment, are investigated in terms of hardness, wear resistance and scratch hardness, compared to the untreated substrate. Numerical simulation allowed optimization of the design of the microwave plasma source, which operated at 2.45 GHz at atmospheric pressure. The proposed microwave plasma oxy-carburizing treatment is localized and can serve to improve the tribological properties of selected regions of the sample; compared to untreated Grade 37 titanium, the oxy-carburized layer presents a decrease in the wear rate at 450 °C against alumina of 54% and an increase in scratch hardness of more than three times
Sorghum used to fodder production in dry farming
In Italy water deficient increase forward to cultivate resistant crops for forage production. In the present research it has been studied the opportunity of using 2 varieties of sorghum: the "Sweet Creek", used as green forage and for silage and the "True", with thinner stalks, used as hay. The fodder production and the dhurrin content during the vegetative phase of the 2 varieties were recorded. Production and chemical characteristics of green and preserved fodders (hay and silage) were determined; moreover the nutritive value and the in vitro digestibility of DM were measured. Results confirm the good adaptation of the sorghum to the water limited conditions as those ones in which the test has been carried out; green and preserved fodders yield were high, however during the hay harvest problems due to the different drying dynamics of leaves and stalks were found. The dhurrin content of these two varieties, even in the young phase, allows the use for grazing of the regrown, which have good bunching
Efficacy and safety of felbamate in children under 4 years of age: a retrospective chart review.
Background and purpose: To review our experience of the efficacy and tolerability of
felbamate in children younger than 4 years. Methods: We used a retrospective chart
review to identify 53 children with seizures who were younger than 4 years. Efficacy
was evaluated based on the occurrence of responsiveness, defined as seizure frequency
reduction of more than 50% for a minimum period of 4 months. Tolerability was
based on parent-reported side effects. Results: Twenty-two (41%) patients resulted to
be responders and 31 (59%) did not. By univariate analysis, those achieving seizure
remission were probably much older, to have a shorter history of epilepsy and a lower
frequency of seizures before felbamate therapy. The number of antiepileptic drugs
(AEDs) used before felbamate therapy was the only significant predictor of the
duration of response to felbamate, with a longer responsiveness to the drug seen in
those who were placed under fewer than three AEDs before felbamate compared with
those who had taken more than three (median, 16 months vs. 7 months; P < 0.0084).
Side effects occurred in 30% of the subjects, but these did not require discontinuation
of the drug. Discussion: Felbamate is an effective medication for a wide range of
epilepsy syndromes in children younger than 4 years. Although caution is necessary
when the drug is used in children, felbamate might represent a possible option for the
treatment of epilepsy in this age group.
Introduction
The incidence of epilepsy is high during the first year of
life and it declines steadily during childhood and
adolescence. Few of the new antiepileptic drugs (AEDs)
are indicated officially for children younger than 4 years
[1–3]. None of them is approved for children younger
than 2 years [1,3,4]. There is a striking discrepancy
between the high incidence of epilepsy in infancy and
the relatively few approved AEDs available for this age
group [5].
Felbamate (2-phenyl-1,3-propanediol dicarbamate) is
a derivative of the anti-anxiety drug meprobamate,
exerting additional anticonvulsant and neuroprotective
properties [6–8]. The drug has been approved since 1993
for the treatment of several types of epilepsy. Experimental
studies suggested that felbamate might inhibit
voltage-dependen
A Multi-Physic Modelling Insight into the Differences between Microwave and Conventional Heating for the Synthesis of TiO2 Nanoparticles
Microwave-assisted synthesis of nanoparticles usually leads to a smaller and more uni-formly distributed particle size compared to conventional heating (e.g., oil bath). Numerical simulation can help to obtain a better insight into the process in terms of temperature distribution or to evidence existing different temperature profiles and heating rates between the two techniques. In this paper multi-physics numerical simulation is used to investigate the continuous flow synthesis of titanium oxide nanoparticles starting from alkoxide precursors. Temperature-dependent permit-tivity of reactants has been measured, including the effects of permanence at the maximum synthesis temperature. A temperature homogeneity index has been defined to compare microwave and conventional heating. Results show that when using microwave heating at 2450 MHz, in the inves-tigated conditions, a much higher temperature homogeneity of the reactants is reached. Moreover, reactants experience different heating rates, depending on their position inside the microwave ap-plicator, while this is almost negligible in the case of conventional heating
L-Idose: an attractive substrate alternative to d-glucose for measuring aldose reductase activity
Although glucose is one of the most important physio-pathological substrates of aldose reductase, it is not an easy molecule for in vitro investigation into the enzyme. In many cases alternative aldoses have been used for kinetic characterization and inhibition studies. However these molecules do not completely match the structural features of glucose, thus possibly leading to results that are not fully applicable to glucose. We show how aldose reductase is able to act efficiently on L-idose, the C-5 epimer of D-glucose. This is verified using both the bovine lens and the human recombinant enzymes. While the kcat values obtained are essentially identical to those measured for D-glucose, a significant decrease in KM was observed. This can be due to the significantly higher level of the free aldehyde form present in L-idose compared to D-glucose. We believe that L-idose is the best alternative to D-glucose in studies on aldose reductase
Efficacy and safety of levetiracetam in infants and young children with refractory epilepsy
SummaryThe aim of this multicentric, retrospective, and uncontrolled study was to evaluate the efficacy and safety of levetiracetam (LEV) in 81 children younger than 4 years with refractory epilepsy. At an average follow-up period of 9 months, LEV administration was found to be effective in 30% of patients (responders showing more than a 50% decrease in seizure frequency) of whom 10 (12%) became seizure free. This efficacy was observed for focal (46%) as well as for generalized seizures (42%). In addition, in a group of 48 patients, we compared the initial efficacy (evaluated at an average of 3 months of follow-up) and the retention at a mean of 12 months of LEV, with regard to loss of efficacy (defined as the return to the baseline seizure frequency). Twenty-two patients (46%) were initial responders. After a minimum of 12 months of follow-up, 9 of 48 patients (19%) maintained the improvement, 4 (8%) of whom remained seizure free. A loss of efficacy was observed in 13 of the initial responders (59%). Maintained LEV efficacy was noted in patients with focal epilepsy and West syndrome. LEV was well tolerated. Adverse events were seen in 18 (34%) patients. The main side effects were drowsiness and nervousness. Adverse events were either tolerable or resolved in time with dosage reduction or discontinuation of the drug.We conclude that LEV is safe and effective for a wide range of epileptic seizures and epilepsy syndromes and, therefore, represents a valid therapeutic option in infants and young children affected by epilepsy
Avaliação de genótipos de soja de diferentes grupos de maturação e resistência aos percevejos.
bitstream/item/71814/1/ID-30968.pd
Dual targeting of ptp1b and aldose reductase with marine drug phosphoeleganin: A promising strategy for treatment of type 2 diabetes
An in-depth study on the inhibitory mechanism on protein tyrosine phosphatase 1B (PTP1B) and aldose reductase (AR) enzymes, including analysis of the insulin signalling pathway, of phosphoeleganin, a marine-derived phosphorylated polyketide, was achieved. Phosphoeleganin was demonstrated to inhibit both enzymes, acting respectively as a pure non-competitive inhibitor of PTP1B and a mixed-type inhibitor of AR. In addition, in silico docking analyses to evaluate the interaction mode of phosphoeleganin with both enzymes were performed. Interestingly, this study showed that phosphoeleganin is the first example of a dual inhibitor polyketide extracted from a marine invertebrate, and it could be used as a versatile scaffold structure for the synthesis of new designed multiple ligands
Rufinamide in refractory childhood epileptic encephalopathies other than Lennox-Gastaut syndrome.
Background: To report on the first multicenter Italian experience with rufinamide as
adjunctive drug in children, adolescents and young adults with refractory childhoodonset
epileptic encephalopathies other than Lennox–Gastaut syndrome.
Methods: Thirty-eight patients (19 males, 19 females), aged between 4 and 34 (mean
13.7 ± 8.3, median 12.5), all affected by different types of childhood-onset refractory
epileptic encephalopathies other than Lennox–Gastaut syndrome, were treated with
rufinamide as adjunctive drug for a mean period of 11.4 months (range 3–26 months).
Results: Fifteen of 38 patients (39.5%) had a ‡50% seizure reduction in countable
seizures. Complete seizure freedom was achieved in one of these patients (2.6%).
Three patients (7.9%) had a 25–49% seizure reduction, whilst seizure frequency
remained unchanged in 15 (39.5%) and increased in five patients (13.1%). Eleven
patients (28.9%) reported adverse side effects. Vomiting was reported in five patients
(13.1%); drowsiness, decreased appetite and irritability with migraine manifested in
other four patients. They were transient and mild in all cases.
Conclusion: Rufinamide may be an effective and well-tolerated adjunctive drug for
the treatment of refractory childhood-onset epileptic encephalopathies other than
Lennox–Gastaut syndrome. Rufinamide was most effective in patients with dropattacks
and (bi)frontal spike–wave discharges.
Introduction
Rufinamide is a structurally triazole-derivative (1-[2,6-
difluorophenyl)methyl]-1hydro-1,2,3-triazole-carboxamide)
novel antiepileptic drug, structurally unrelated to
the existing antiepileptic drugs, and approved by the
Food and Drug Administration for the treatment of
Lennox–Gastaut syndrome in patients aged 4 and over,
and for the treatment of partial seizures in adults and
adolescents.
The proposed mechanism of action is the limitation
of excessiv
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