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991.
A series of novel isosteric analogs of the ceramidase inhibitors, (1S,2R)-N-myristoylamino-phenylpropanol-1 (d-e-MAPP) and (1R,2R)-N-myristoylamino-4'-nitro-phenylpropandiol-1,3 (B13), with modified targeting and physicochemical properties were designed, synthesized, and evaluated as potential anticancer agents. When MCF7 cells were treated with the analogs, results indicated that the new analogs were of equal or greater potency compared to the parent compounds. Their activity was predominantly defined by the nature of the modification of the N-acyl hydrophobic interfaces: N-acyl analogs (class A), urea analogs (class B), N-alkyl analogs (class C, lysosomotropic agents), and omega-cationic-N-acyl analogs (class D, mitochondriotropic agents). The most potent compounds belonged to either class D, the aromatic ceramidoids, or to class C, the aromatic N-alkylaminoalcohols. Representative analogs selected from this study were also evaluated by the National Cancer Institute In Vitro Anticancer Drug Discovery Screen. Again, results showed a similar class-dependent activity. In general, the active analogs were non-selectively broad spectrum and had promising activity against all cancer cell lines. However, some active analogs of the d-e-MAPP family were selective against different types of cancer. Compounds LCL85, LCL120, LCL385, LCL284, and LCL204 were identified to be promising lead compounds for therapeutic development.  相似文献   
992.
Forty-eight species of Astragalus L. sections Onobrychoidei DC., Uliginosi Gray and Ornithopodium Bunge (Fabaceae) in Turkey were studied in order to describe and investigate their seed morphologies and to evaluate the diagnostic value of this character using a stereoscopic microscope and a scanning electron microscope (SEM). SEM pictures of seeds were taken as a whole and in detail. The systematic implications of the findings are discussed. Six main seed types were observed. A key to identifying the different seed types is provided.  相似文献   
993.
In this study, 121 wild edible plants used as food in Anatolia were surveyed to determine the plant parts used and their detailed preparation methods. The results of this study show that the plants may be boiled, fried in fat, and eaten raw or as rolled vegetables. They may also be consumed as pickles, fruits, sweets and spices, and drunk as cold and hot drinks. Thirty species (8 genera) were identified as belonging to the Lamiaceae family, 15 species (15 genera) belong to the Asteraceae family, 13 species (5 genera) belong to the Rosaceae family, 8 species (7 genera) belong to the Brassicaceae family, 6 species (3 genera) belong to the Orchidaceae family and 5 species (5 genera) belong to the Apiaceae family. The genera represented by the highest number of species in the study are as follows:Sideritis L. is represented by 13 species, Origanum L. by 7 species,Rubus L. by 5 species,Thymus L. by 4 species andRumex L. by 4 species.  相似文献   
994.
SUMMARY: Sphingolipids are a structurally diverse group of molecules based on long-chain sphingoid bases that are found in animal, fungal and plant cells. In contrast to the situation in animals and yeast, much less is known about the spectrum of sphingolipid species in plants and the roles they play in mediating cellular processes. Here, we report the cloning and characterization of a plant ceramidase from rice (Oryza sativa spp. Japonica cv. Nipponbare). Sequence analysis suggests that the rice ceramidase (OsCDase) is similar to mammalian neutral ceramidases. We demonstrate that OsCDase is a bona fide ceramidase by heterologous expression in the yeast double knockout mutant Deltaypc1Deltaydc1 that lacks the yeast ceramidases YPC1p and YDC1p. Biochemical characterization of OsCDase showed that it exhibited classical Michaelis-Menten kinetics, with optimum activity between pH 5.7 and 6.0. OsCDase activity was enhanced in the presence of Ca(2+), Mg(2+), Mn(2+) and Zn(2+), but inhibited in the presence of Fe(2+). OsCDase appears to use ceramide instead of phytoceramide as a substrate. Subcellular localization showed that OsCDase is localized to the endoplasmic reticulum and Golgi, suggesting that these organelles are sites of ceramide metabolism in plants.  相似文献   
995.
The ammonia fiber expansion (AFEX) process has been shown to be an effective pretreatment for lignocellulosic biomass. Technological advances in AFEX have been made since previous cost estimates were developed for this process. Recent research has enabled lower overall ammonia requirements, reduced ammonia concentrations, and reduced enzyme loadings while still maintaining high conversions of glucan and xylan to monomeric sugars. A new ammonia recovery approach has also been developed. Capital and operating costs for the AFEX process, as part of an overall biorefining system producing fuel ethanol from biomass have been developed based on these new research results. These new cost estimates are presented and compared to previous estimates. Two biological processing options within the overall biorefinery are also compared, namely consolidated bioprocessing (CBP) and enzymatic hydrolysis followed by fermentation. Using updated parameters and ammonia recovery configurations, the cost of ethanol production utilizing AFEX is calculated. These calculations indicate that the minimum ethanol selling price (MESP) has been reduced from $1.41/gal to $0.81/gal.  相似文献   
996.
A cation exchanging material was developed from lemon by modifying the pectic-cellulosic substances in the lemon peel by lemon juice having citric acid. For this purpose, chopped lemon removed from seeds and yellow skin was heated in two stages, firstly at 50 degrees C for 24h and subsequently at 120 degrees C for 2h. The material obtained was ground, repeatedly washed with water and dried. Lemon peel and lemon resin obtained were characterized through physicochemical analyses and FTIR spectroscopy. Heavy metal binding performance of this material was determined by removal tests conducted by using 10mM solutions of divalent metals. Experimental results show that the resin prepared from lemon is effective especially for Pb and Cu removals. For a lemon resin dosage of 10 g l(-1), sorption affinity of divalent metal ions is found to be in an order of Pb>Cu>Ni>Fe>Cd>Zn>Co>Mn. Typically, sorption capacities are about 0.87 and 0.43 mmol g(-1) for Pb and Mn, respectively.  相似文献   
997.
Pea lectin was exposed to a pH range of 7-13. It was observed that alkaline-unfolding resulted in a molten globule-like intermediate at pH 11. The structural stability of this alkaline unfolded molten globule-like state of pea lectin was studied in the presence of HFIP. Thermal studies showed that this state was more susceptible to thermal denaturation as compared to the native state and it became even more so in presence of HFIP.  相似文献   
998.

Background

Tobacco smoke and genetic susceptibility are risk factors for asthma and wheezing. The aim of this study was to investigate whether there is a combined effect of interleukin-13 gene (IL13) polymorphisms and tobacco smoke on persistent childhood wheezing and asthma.

Methods

In the Isle of Wight birth cohort (UK, 1989–1999), five IL13 single nucleotide polymorphisms (SNPs): rs1800925 (-1112C/T), rs2066960, rs1295686, rs20541 (R130Q) and rs1295685 were genotyped. Parents were asked whether their children had wheezed in the last 12 months at ages 1, 2, 4 and 10 years. Children who reported wheeze in the first 4 years of life and also had wheezing at age 10 were classified as early-onset persistent wheeze phenotype; non-wheezers never wheezed up to age 10. Persistent asthma was defined as having a diagnosis of asthma both during the first four years of life and at age 10. Logistic regression methods were used to analyze data on 791 children with complete information. Potential confounders were gender, birth weight, duration of breast feeding, and household cat or dog present during pregnancy.

Results

Maternal smoking during pregnancy was associated with early-onset persistent wheeze (OR 2.93, p < 0.0001); polymorphisms in IL13 were not (OR 1.15, p = 0.60 for the common haplotype pair). However, the effect of maternal smoking during pregnancy was stronger in children with the common IL13 haplotype pair compared to those without it (OR 5.58 and OR 1.29, respectively; p for interaction = 0.014). Single SNP analysis revealed a similar statistical significance for rs20541 (p for interaction = 0.02). Comparable results were observed for persistent childhood asthma (p for interaction = 0.03).

Conclusion

This is the first report that shows a combined effect of in utero exposure to smoking and IL13 on asthma phenotypes in childhood. The results emphasize that genetic studies need to take environmental exposures into account, since they may explain contradictory findings.  相似文献   
999.

Background  

Eukaryotic promoter prediction using computational analysis techniques is one of the most difficult jobs in computational genomics that is essential for constructing and understanding genetic regulatory networks. The increased availability of sequence data for various eukaryotic organisms in recent years has necessitated for better tools and techniques for the prediction and analysis of promoters in eukaryotic sequences. Many promoter prediction methods and tools have been developed to date but they have yet to provide acceptable predictive performance. One obvious criteria to improve on current methods is to devise a better system for selecting appropriate features of promoters that distinguish them from non-promoters. Secondly improved performance can be achieved by enhancing the predictive ability of the machine learning algorithms used.  相似文献   
1000.
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