912 resultados para Somatostatin analogues
Resumo:
In this paper, reanalysis fields from the ECMWF have been statistically downscaled to predict from large-scale atmospheric fields, surface moisture flux and daily precipitation at two observatories (Zaragoza and Tortosa, Ebro Valley, Spain) during the 1961-2001 period. Three types of downscaling models have been built: (i) analogues, (ii) analogues followed by random forests and (iii) analogues followed by multiple linear regression. The inputs consist of data (predictor fields) taken from the ERA-40 reanalysis. The predicted fields are precipitation and surface moisture flux as measured at the two observatories. With the aim to reduce the dimensionality of the problem, the ERA-40 fields have been decomposed using empirical orthogonal functions. Available daily data has been divided into two parts: a training period used to find a group of about 300 analogues to build the downscaling model (1961-1996) and a test period (19972001), where models' performance has been assessed using independent data. In the case of surface moisture flux, the models based on analogues followed by random forests do not clearly outperform those built on analogues plus multiple linear regression, while simple averages calculated from the nearest analogues found in the training period, yielded only slightly worse results. In the case of precipitation, the three types of model performed equally. These results suggest that most of the models' downscaling capabilities can be attributed to the analogues-calculation stage.
Resumo:
This dissertation will cover several disparate topics, with the overarching theme centering on the investigation of organometallic C-H activation and hydrocarbon transformation and upgrading. Chapters 2 and 3 discuss iridium and rhodium analogues of the Shilov cycle catalyst for methane to methanol oxidation, and Chapter 4 on the recently discovered ROA mechanistic motif in catalysts for various alkane partial oxidation reactions. In addition, Chapter 5 discusses the mechanism of nickel pyridine bisoxazoline Negishi catalysts for asymmetric and stereoconvergent C-C coupling, and the appendices discuss smaller projects on rhodium H/D exchange catalysts and DFT method benchmarking.
Resumo:
In a 1955 paper, Ky Fan, Olga Taussky, and John Todd presented discrete analogues of inequalities of Wirtinger type, and by taking limits they were able to recover the continuous inequalities. We generalize their techniques to mixed and higher derivatives and inequalities with weight functions in the integrals. We have also considered analogues of inequalities of Müller and Redheffer and have used these inequalities to derive a necessary and sufficient condition on ordered pairs of numbers so that the first number is the square norm of the kth derivative of some periodic function and the second number is the square norm of the mth derivative of the same periodic function.
Resumo:
Lobster analogues were prepared with lobster base flavour (paste),h lobster cook water (whole lobster omogenate:water, 1:1 and 1:0.5) and lobster meat mince. In another experiment, different combinations of ginger-garlic paste and lobster base flavour, i.e., 1:3, 1:4, 1:6, 3:3, 3:4, 3:6, 5:3, 5:4 and 5:6 were added to the lobster analogue paste. It was observed that lobster analogues prepared with lobster base flavour (paste) are suitable organoleptically. The combination of ginger garlic paste and lobster base flavour in the ratio of 3:4 was found to be suitable organoleptically. Lobster analogues coloured with annatto seed colour at 1:2 (annatto seed:water) concentration had high values for the colour attribute as compared to orange-red synthetic colour, beetroot colour, caramel colour and paprika colour. It was observed that come-up-time to achieve a temperature of850°C was 28 minutes with a processing period of 11 minutes.
Resumo:
Flazin isolated from the fruiting bodies of Suillus granulatus was found to possess weak anti-HIV activity (EC50=2.36 mu m, TI= 12.1). To establish a SAR study, 46 flazin analogues were synthesized, and their anti-HIV activities were evaluated in vitro. A
Resumo:
Chinese sturgeon (Acipenser sinensis) is a rare and endangered species and also an important resource for the sturgeon aquaculture industry. SMART cDNA was synthesized from the hypothalamus of Chinese sturgeon, and the full-length cDNAs of two somatostatin (SS) genes were cloned and sequenced. The first cDNA (AsSS1) encodes a 116-amino acid protein that contains the SS14 sequence at its C-terminal extremity. AsSS1 shows high identity to that of human and other vertebrates. The second cDNA (AsSS2) encodes a 111-amino acid protein that contains the somatostatin variant [Pro(2)]-SS14 at its C-terminal extremity. Both the two SS mRNAs were expressed in brain and pituitary with different mRNA levels. But in peripheral tissues, AsSS2 was more widely distributed than AsSS1. High mRNA levels of AsSS2 were found in liver, kidney and heart, while low mRNA levels of AsSS2 were also detected in ovary. Throughout embryogenesis and early larval development only AsSS2 mRNAs were detected. Furthermore, in the hypothalamus of one to five year-old Chinese sturgeon, AsSS2 but not AsSS1 maintained stable expression. The mRNA distribution suggests that the Chinese sturgeon AsSS2 products play important physiological functions in adult fish as well as in cell growth and organ differentiation in embryo and larva development. (C) 2009 Elsevier Inc. All rights reserved.
Resumo:
A facile and efficient one-pot synthesis of substituted cyclophosphamidic chlorides and their analogues has been developed from readily available enaminones, 2-arylamino-3-acetyl-5,6-dihydro4H-pyrans.
Resumo:
The solvent extraction of rare earths from chloride solution has been investigated using mixtures of 2-ethylhexylphosphonic acid mono-(2-ethylhexyl) ester (HEHEHP, P507) and organophosphorus acids [di-(2-ethylhexyl)phosphoric acid (HDEHP, P204), isopropylphosphonic acid 1-hexyl-4-ethylocryl ester (HHEOIPP), bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex 272), bis(2,4,4-trimethylpentyl)monothiophosphinic acid (Cyanex 302), and bis(2,4,4-trimethypentyl)dithiophosphinic acid (Cyanex 301)]. Results show that the extractability of the selected extractants for rare earths decreases in the order: HEHEHP/HDEHP > HEHEHP/Cyanex 301 > HEHEHP/HHEOIPP > HEHEHP/Cyanex 302 > HEHEHP/Cyanex 272. A possible explanation of the different extractabilities is given based on the structure of the extractants. Furthermore, the possibilities of the separation of adjacent rare earths with these mixtures were investigated according to the extractabilities; the results show the possibility of separating the rare earths.
Resumo:
Two new polyacid derivative ligands of thienyl-substituted terpyridine analogues, N,N,N-1,N-1-[4'-(2"'-thienyl)-2,2':6',2"-terpyridine-6,6"-diyl]bis(methylenenitrilo) tetrakis(acetic acid) (TTTA) and N,N,N-1,N-1-[2,6-bis(3'-amino-methyl-1'-pyrazolyl)-4-(2"-thienyl)pyridine] tetrakis(acetic acid) (BTTA), were synthesized, and the luminescence properties of their Eu3+ and Tb3+ chelates were investigated. The Eu3+ chelates of the two ligands are strongly luminescent having luminescence quantum yields of 0.150 (TTTA-Eu3+) and 0.114 (BTTA-Eu3+), and lifetimes of 1.284 ms (TTTA-Eu3+) and 1.352 ms (BTTA-Eu3+), whereas their Tb3+ chelates are weakly luminescent. The TTTA-Eu3+ chelate was used for streptavidin (SA) labeling, and the labeled SA was used for time-resolved fluoroirnmunoassay of insulin in human sera. The method gives the detection limits of 33 pg ml(-1). (C) 2003 Elsevier B.V. All rights reserved.