241 research outputs found
Surfactant Aided Reductive Carbonylation of Nitrobenzene inWater Catalyzed by Pd Complexes
The catalytic carbonylation of nitroarenes is a field of high interest from a technological point of view, since provides an environmentally benign route to a number of important industrial
products, such as isocyanates, carbamates, ureas, azoarenes and azoxyarenes, amines, amides, oximes and several types of heterocyclic compounds. The reductive carbonylation of
nitrobenzene in water carried out by using Pd(II)-solvable catalyst precursors, leads to aniline, as major product. In the present paper we propose the micellar catalytic reductive
carbonylation of nitrobenzene in water. The Pd(II) catalyst precursors tested are synthesized by using cheaper commercial insolvable ligands, such as triphenylphosphine (PPh3), 1,3-
bis(diphenylphosphino)propane (dppp) and 1, 10-phenantroline (phen). The influence on the conversion and on the selectivity of such precursors has been evaluated in combination with
commercial anionic (SDS), cationic (TBAB) and non ionic (Triton X 100) surfactants.
We have found that all the Pd(II) complexes tested are efficiently dissolved in each O/W emulsions but the conversion is strongly influenced by the nature of ligand. By using Pd(OAc)2(PPh3)2, high selectivity towards azo- and azo-oxybenzene has been obtained. The influence of some reaction parameters has been further evaluated and optimized
“A Torino non si muore di fame”. Riflessioni antropologiche su cibo e povertà estrema
Grounded in a longstanding action-research about the homelessness and welfare system of Turin, the article analyses how public and private services tackle the issue of homelessâ food poverty. Drawing on the anthropological understanding of nutrition, it will be argued that traditional food supply chains for homeless people reduce food to the bare biological dimension, ignoring the social, cultural, and psychological features. Afterward, the article describes how the action-research project âCostruire Bellezzaâ (CB), a permanent laboratory for homeless people, deals with the food issue. CB represents an interesting case-study where different responses to the nutrition challenge have been developed to take into consideration the multidimensional nature of eating. In the project, food is a core field where is possible to create relationships, develop capacities, exercising oneâs own voice. The insights matured in CB contributes to promote a reflexive transformation on the a wider system of services, that produced the systemic program âAlimentaâ
Trypanosoma brucei bloodstream forms express highly specific and separate transporters for adenine and hypoxanthine; evidence for a new protozoan purine transporter family?
The transport of nucleobases and nucleosides in protozoan parasites is known to be performed by Equilibrative Nucleoside Transporter (ENT) family members, including the extensively studied P1 and P2 nucleoside transporters of T. brucei bloodstream forms. Studies with P2 knockout parasites suggested the existence of as yet uncharacterised purine transport mechanisms in these cells. Here, we deleted several ENT genes, in addition to P2, including an array comprising three genes encoding for high-affinity broad-selectivity nucleobase transporters - the longest multi-gene locus deletion in T. brucei to date. It was verified that none of them appreciably contributed to the transport of hypoxanthine in bloodstream forms grown axenically in HMI-9 medium, which was mainly performed by a previously not described hypoxanthine-specific transporter (HXT1) with a Km of 22âŻÂ±âŻ1.7âŻÎŒM and Vmax of 0.49âŻÂ±âŻ0.06âŻpmol(107 cells)-1s-1. The uptake of adenine was also assessed in the knockout cells and was performed by a highly specific adenine transporter (ADET1) with a Km of 573âŻÂ±âŻ62âŻnM and Vmax of 0.23âŻÂ±âŻ0.06âŻpmol(107 cells)-1âŻs-1. Neither HXT1 nor ADET1 displayed any affinity for other natural purines or pyrimidines and could not be completely inhibited by hypoxanthine or adenine analogues. These carriers may be the final pieces in the substantial transporter array trypanosomes can employ to fine-tune the uptake of purines from diverse environments during their life cycles, and may be encoded by genes other than those of the ENT family
âDesign is oneâ, un canone grafico del progetto di social design; 10 anni di ricerca-azione
Ragioneremo attorno alla nostra esperienza progettuale, consapevoli che esiste un aspetto comunicativo in ogni progetto e concordi che indagare e interrogare questa dimensione permetta di comprendere e definire âmeglio le funzioni e scoprire altri tipi di funzionalitĂ [âŠ] altrettanto essenziali che la pura considerazione funzionalistica impediva di scorgereâ. Nel nostro lavoro di ricerca-azione partecipativa, infatti, funzione e comunicazione, prestazione e messaggio interagiscono nel corso di tutto il ciclo di vita del progetto
Quando l’antropologia incontra il design. Riflessioni a margine di una ricerca-azione a contrasto dell’homelessness
Risk factors for development of symptoms after autologous transplantation for multiple myeloma
Inhibition of phosphodiesterase 5 restores endothelial function in renovascular hypertension
Background: the clipping of an artery supplying one of the two kidneys (2K1C) activates the renin-angiotensin (Ang) system (RAS), resulting in hypertension and endothelial dysfunction. Recently, we demonstrated the intrarenal beneficial effects of sildenafil on the high levels of Ang II and reactive oxygen species (ROS) and on high blood pressure (BP) in 2K1C mice. Thus, in the present study, we tested the hypothesis that sildenafil improves endothelial function in hypertensive 2K1C mice by improving the NO/ROS balance.Methods: 2K1C hypertension was induced in C57BL/6 mice. Two weeks later, they were treated with sildenafil (40 mg/kg/day, via oral) or vehicle for 2 weeks and compared with sham mice. At the end of the treatment, the levels of plasma and intrarenal Ang peptides were measured. Endothelial function and ROS production were assessed in mesenteric arterial bed (MAB).Results: the 2K1C mice exhibited normal plasma levels of Ang I, II and 1-7, whereas the intrarenal Ang I and II were increased (similar to 35% and similar to 140%) compared with the Sham mice. Sildenafil normalized the intrarenal Ang I and II and increased the plasma (similar to 45%) and intrarenal (+15%) Ang 1-7. the 2K1C mice exhibited endothelial dysfunction, primarily due to increased ROS and decreased NO productions by endothelial cells, which were ameliorated by treatment with sildenafil.Conclusion: These data suggest that the effects of sildenafil on endothelial dysfunction in 2K1C mice may be due to interaction with RAS and restoring NO/ROS balance in the endothelial cells from MAB. Thus, sildenafil is a promising candidate drug for the treatment of hypertension accompanied by endothelial dysfunction and kidney disease.Conselho Nacional de Desenvolvimento CientĂfico e TecnolĂłgico (CNPq)State Agency for the Development of Science and Technology (FAPES/Universal)Univ Fed Espirito Santo, Hlth Sci Ctr, Lab Translat Physiol, Vitoria, ES, BrazilEmescam Sch Hlth Sci, Vitoria, ES, BrazilUniversidade Federal de SĂŁo Paulo, Dept Med, Div Nephrol, SĂŁo Paulo, BrazilUniv Fed Espirito Santo, Hlth Sci Ctr, Pharmaceut Sci Grad Program, Vitoria, ES, BrazilUniv Fed Paraiba, Hlth Sci Ctr, Dept Physiol & Pathol, BR-58059900 Joao Pessoa, PB, BrazilUVV, Pharmaceut Sci Grad Program, Vila Velha, ES, BrazilFed Inst Educ Sci & Technol IFES, Vila Velha, ES, BrazilUniversidade Federal de SĂŁo Paulo, Dept Med, Div Nephrol, SĂŁo Paulo, BrazilCNPq: 302582/2011-8CNPq: 476525/2012-8CNPq: 305188/2012-7CNPq: 473177/2013-7State Agency for the Development of Science and Technology (FAPES/Universal): 012/2011State Agency for the Development of Science and Technology (FAPES/Universal): 54498465CNPq: 012/2009Web of Scienc
Sildenafil ameliorates oxidative stress and DNA damage in the stenotic kidneys in mice with renovascular hypertension
Background: Oxidative stress and DNA damage have been implicated in the pathogenesis of renovascular hypertension induced by renal artery stenosis in the two-kidney, one-clip (2K1C) Goldblatt model. Considering our previous report indicating that the chronic blockade of phosphodiesterase 5 with sildenafil (Viagra (R)) has marked beneficial effects on oxidative stress and DNA damage, we tested the hypothesis that sildenafil could also protect the stenotic kidneys of 2K1C hypertensive mice against oxidative stress and genotoxicity.Methods: the experiments were performed with C57BL6 mice subjected to renovascular hypertension by left renal artery clipping. Two weeks after clipping, the mice were treated with sildenafil (40 mg/kg/ day for 2 weeks, 2K1C-sildenafil group) or the vehicle (2K1C). These mice were compared with control mice not subjected to renal artery clipping (Sham). After hemodynamic measurements, the stenotic kidneys were assessed using flow cytometry to evaluate cell viability and the comet assay to evaluate DNA damage. Measurements of intracellular superoxide anions and hydrogen peroxide levels as well as nitric oxide bioavailability were also obtained.Results: Sildenafil treatment significantly reduced mean arterial pressure (15%), heart rate (8%), intrarenal angiotensin II (50%) and renal atrophy (36%). in addition, it caused a remarkable decrease of reactive oxygen species production. On the other hand, sildenafil increased nitric oxide levels relative to those in the nontreated 2K1C mice. Sildenafil treatment also significantly reduced the high level of kidney DNA damage that is a characteristic of renovascular hypertensive mice.Conclusions: Our data reveal that sildenafil has a protective effect on the stenotic kidneys of 2K1C mice, suggesting a new use of phosphodiesterase 5 inhibitors for protection against the DNA damage observed in the hypoperfused kidneys of individuals with renovascular hypertension. Further translational research is necessary to delineate the mechanisms involved in the prevention of renal stenosis in the clinical setting.Conselho Nacional de Desenvolvimento CientĂfico e TecnolĂłgico (CNPq)State Agency for the Development of Science and Technology (FAPES)Univ Fed Espirito Santo, Hlth Sci Ctr, Lab Translat Physiol, Vitoria, ES, BrazilUniv Fed Paraiba, Hlth Sci Ctr, Dept Physiol & Pathol, BR-58059900 Joao Pessoa, Paraiba, BrazilUniversidade Federal de SĂŁo Paulo, Dept Med, Div Nephrol, SĂŁo Paulo, BrazilUniv Vila Velha, Pharmaceut Sci Grad Program, Vila Velha, ES, BrazilFed Inst Educ Sci & Technol IFES, Vila Velha, ES, BrazilUniversidade Federal de SĂŁo Paulo, Dept Med, Div Nephrol, SĂŁo Paulo, BrazilCNPq: 302582/2011-8CNPq: 476525/2012-8CNPq: 305188/2012-7CNPq: 473177/2013-7State Agency for the Development of Science and Technology (FAPES): 54498465CNPq: 012/2009Web of Scienc
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