130,481 research outputs found
Difference in the development of tolerance to morphine and D.-ala2 -Methionine-Enkephalin in C57 BL/6J mice
No full textThe analgesic effect elicited by intracerebroventricular (icv) administration of either morphine or d-ala2-methionine-enkephalin (d-ala2-met-enk) was studied during the onset and offset of morphine tolerance in DBA/2J (DBA) and C57 BL/6J (C57) strains of mice. DBA mice become tolerant to the analgesic effect of morphine icv injected after receiving 8 subcutaneous (sc) injections (2 injections daily × 4 days) of the ED50 of morphine for analgesia. In c57 mice tolerance to morphine icv-administered is evident after only a single sc injection of morphine ED50. On the contrary the development of cross-tolerance to the analgesic effect of d-ala2-met-enk is similar in both strains of mice. With respect to the offset period, the recovery of the analgesic effect of morphine and d-ala2-met-enk is slower in C57 than in DBA mice; in C57 mice tolerance to both morphine and d-ala2-met-enk is still present 10 days after morphine withdrawal. These results suggest the existence of a strain dependent rate in the onset of tolerance to the analgesic effect of morphine. C57 mice represent an interesting tool to investigate tolerance to opiates and opioid peptides
Synthesis of 1,2,3,4-tetrahydroisoquinolines and 2,3,4,5-tetrahydro-1H-2 benzazepines combining sequential palladium-catalysed ortho alkylation/vinylation with aza-Michael addition reactions
No full textNew Taxane Derivatives: Synthesis of Baccatin[14,1-d]furan-2-one Nucleus and Its Condensation with the Norstatine Side Chain
No full textNew taxanes 15 and 18, containing the unsaturated and saturated baccatin[14,1-d]furan-2-one nucleus, respectively, were prepared starting from the readily available 13-oxo-7-Tes-baccatin III
(3). Sequential formation of the enolate of 3 and reaction with ethyl glyoxylate gave the 13-oxo-
7-Tes-baccatin[14,1-d]-3,4-dehydrofuran-2-one 4. The reduction of 4 can result in the formation of
a mixture of compounds corresponding to 13-hydroxy alcohol 5 and 13-enol derivative 6. Both 5
and 6 were transformed into 13-oxo-7-Tes-baccatin[14,1-d]furan-2-one 8 by treatment with a base.
Further reduction of 8 gave 13-hydroxy compound 9. Esterification of 6 and 9 with N,O-protected norstatine 12, followed by deprotection, gave the new promising anticancer taxanes 15 and 18, respectively
Palladium-catalyzed cyclization of N-n-butyl, N-(o-iodobenzyl)-3-butenamides: six- versus seven- and eight-membered ring formation
No full textSurvey on housing, management and welfare of dairy cattle in tie-stalls in western Italian Alps
No full textIn the Alps, the traditional breeding system for dairy cattle is based on the alternation between a free ranging period on mountain ranges during the summer, and an indoor period in tie-stalls in the cold season. Several welfare issues may arise in tie-stall housing systems. We described the situation in 47 farms in three villages in Western Italy, trying to identify possible relationships among structural and management characteristics, animal health and behaviour traits. A long duration of the grazing periods, associated with frequent manure removal during the housing period, are probably key factors for limiting the occurrence of lameness. Teat trauma are more common in narrower stalls. Getting up behaviour is unnatural in most of the visited farms. Some lacks in the farmers' knowledge of animal behaviour was pointed out. Some structural and management characteristics are strictly related to geographic constraints. However, situation permitting, some expedients may be achieved for improving welfare levels
A simple catalytic synthesis of condensed pyridones from o-bromoarylcarboxamides involving ipso substitution via palladacycles
No full textSynthesis of 6-phenanthridinones and their heterocyclic analogues through palladium-catalyzed sequential aryl-aryl and N-aryl coupling
No full text6-Phenanthridinones and their heterocyclic analogues were synthesized through a onepot
procedure based on consecutive Pd-catalyzed aryl−aryl and N-aryl coupling from
iodoarenes ortho-substituted by electron-releasing substituents and amides of obromoarene-
and heteroarenecarboxylic acids
Action of opiates, antipsychotics, amphetamine and apomorphine on dopamine receptors in rat striatum: in vivo changes of 3′,5′-cyclic amp content and acetylcholine turnover rate
No full textDirect chromatographic methods for enantioresolution of amino acids: recent developments
No full textα-Amino acids are present in two opposite configurations due to the presence of a central carbon atom which is a chiral center. While l-amino acids are present in large amount in nature, only tiny quantities of their d-enantiomers exist. For a long time, d-amino acids have been considered of bacterial origin only, but recently we realized that they are present in all living organisms: notably, d-amino acids play specific and relevant functions in the different organisms. Detection and quantification of d-amino acids are mandatory to shed light on their physiological roles, especially related to foods and human health. Chromatographic techniques are among the most commonly used analytical methods for the enantioseparation of amino acids. Here, we revised the latest improvements in chromatographic direct methodologies based on chiral selectors and aimed to improve analytical speed, sensitivity, robustness, and reproducibility. While current methods are well suited for d-amino acid analysis in foodstuffs and pharmaceuticals, further improvements seem required for their simultaneous, fast and sensitive detection in biological fluids, an emerging field since d-amino acids have been proposed as biomarkers of different and relevant human pathologic states
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
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