Search results for "donor"
showing 10 items of 436 documents
Glycosyl azides as building blocks in convergent syntheses of oligomeric lactosamine and Lewisx saccharides
1997
Abstract Oligosaccharides containing type 2 lactosamine repeating units, e.g. neo-lacto-octaose and trimeric Lewis x derivatives, are constructed using neo-lactosamine azide building blocks. The azido group provides a favorable protection of the anomeric position which is stable to versatile protecting group manipulations and glycosylation reactions. On the other hand, glycosyl azides can be converted into glycosyl fluorides via a 1,3-dipolar cycloaddition with di- tert -butyl-acetylenedicar☐ylate and subsequent treatment of the resulting N -glycosyl triazoles with hydrogen fluoride-pyridine complex. Activation of the lactosamine fluorides with Lewis acids affords the possibility to extend …
A new method of anomeric protection and activation based on the conversion of glycosyl azides into glycosyl fluorides
1993
Glycosyl azides provide reliable anomeric protection stable to conditions for hydrolytic removal of ester groups, for reductive opening or release of acetalic diol protection, for the introduction of ether-type protection, and for glycosylation processes. The utility of this anomeric protection is further enhanced as glycosyl azides may be converted into glycosyl fluorides, which can be activated for glycosylation reactions. To this end, glycosyl azides have been subjected to 1,3-dipolar cycloaddition with di-tert-butyl acetylenedicarboxylate. On treatment with hydrogen fluoride-pyridine complex the N-glycosyl triazole derivatives directly give glycosyl fluorides.
Acene-type donors bearing one 1,3-dithiole ring
1999
Abstract A series of acene-type donors bearing only one 1,3-dithiole ring have been synthesized by following a Wittig-Horner reaction from 7 H -benz[ d,e ]anthracen-7-one and several phosphonate esters. The excellent donor properties have been studied using both experimental techniques and quantum-chemical calculations and reveal that the extraction of the first electron in the oxidation process occurs from the dithiole ring (0.42 e) and the acene unit (0.58 e).
Ethical aspects of Fecal Microbiota Transplantation (FMT).
2015
The importance of human microbiota in preserving human organism healthy is nowadays well acknowledged. The alteration of the microbiota can be the consequence of a persistent use of antibiotics or immunosuppressive medications or abdominal irradiation or surgery, wrong diet, or can be caused by surgery or anatomical condition. These alterations can cause many infections and diseases that today can be treated with Fecal Microbiota Transplantation (FMT), also called Bacteriotherapy, that is the administration of a fecal solution from a donor into the intestinal tract of a recipient. Although to date, FMT appears to be safe and without serious adverse effects, there are some ethical issues tha…
Are blood donors an adequate control group to ascertain HCV prevalence in non-Hodgkin’s lymphoma patients?
2002
Screening sierologico per Leishmania infantum su donatori di sangue e HIV+ asintomatici residenti in area endemica [Serological screening for Leishma…
2008
Visceral leishmaniasis (VL) is endemic in Sicily (48 new cases in 2004, of which nine were in Agrigento). In southern Europe between 25-70 per cent of adult VL cases are related to HIV infection. The HIV cases have a high risk (1.5-9%) of developing VL either as a new infection or as the revival of a latent infection. We therefore carried out serologic screening to detect antibodies against L. infantum by IFAT in 1449 blood donors in Agrigento and the surrounding area (May-December 2005) and in 120 HIV+ in western Sicily, all of whom were asymptomatic and had no history of VL. L. DNA was assessed by nested PCR in blood samples of some seropositive donors. Of the 1449 blood donors, 11 (0.75%…
Serological screening for Leishmania infantum in asymptomatic blood donors living in an endemic area (Sicily, Italy)
2005
The purpose of our study was to assess whether Leishmania infantum parasitemia occurs in asymptomatic Leishmania-seropositive subjects. Samples from 500 blood donors were tested using an enzyme-linked immunosorbent assay (ELISA). Anti-Leishmania antibodies were not found in any sample. Our findings suggest that the risk of L. infantum transmission by blood transfusion in Sicily is very low.
Routine HCV PCR screening of blood donations to identify early HCV infection in blood donors lacking antibodies to HCV
2001
BACKGROUND: Detection of early hepatitis C infection of blood donors is still a major problem for blood transfusion. Common anti-HCV screening assays show differences in sensitivity and specificity. The often mild symptoms of acute hepatitis C also cause difficulties in the identification of early HCV infection. The feasibility and efficacy of routine screening of blood donations for HCV RNA were investigated. STUDY DESIGN AND METHODS: Blood donations (n = 251,737) were screened for HCV RNA over 4 years. RNA extraction, amplification, and detection were done by two commercial HCV PCR kits (HCV Cobas Amplicor and HCV Cobas Amplicor 2.0, Roche Diagnostics). Screening was done by pool testing …
Photoluminescence quantum yield exceeding 80% in low dimensional perovskite thin-films via passivation control
2017
Quasi-2D perovskites with the BA : MA molar ratio equal to 3 : 3 show a remarkable PLQY exceeding 80%, thanks to the use of an electron donor as the passivating agent. These films have been applied in LEDs that exhibit high brightness exceeding 1000 cd m−2 and current efficiencies >3 cd A−1.