课程文献中心 更多>>

关键词： Seaweed   Microalgae   Taxonomical identification   Estimated daily intake   Multiple regression analysis   MEDITERRANEAN SEA COAST   SEAWEED   BROWN   LIPIDS   QUANTITATION   RESPONSES   MINERALS   ELEMENTS   BROMINE  

摘要： Marine algae have made a strong contribution to global food security in the future. This study is the first report describing the concentration, pathways, and interactions of halogens in 15 species of marine algae collected from the Eastern Harbor in Alexandria, Egypt, relative to 22 key variables. The relationship between halogen content and chemical and biochemical parameters was studied through multivariate analysis. Among all the tested algae, the iodine content was the lowest (2.53-3.00 mu g/g). The range of fluoride and chloride in macroalgae (1.12-1.70 and 0.10-0.46 mg/g) was smaller than that of microalgae (0.10-0.46 and 1.48-3.17 mg/g). The bromide content in macroalgae (0.36-5.45 mg/g) was higher than that in microalgae (0.40-0.76 mg/g). The halogen content in macroalgae was arranged in the order of Br > F > Cl > I. In addition, the biochemical parameters such as carbohydrates, proteins, lipids, and certain heavy metals (Fe, Zn, Cu, Mn, Pb, Ni, Co, Cd, and Cr) were determined. Calories, energy, total antioxidant activity (TAC), K/Na, and ion quotient amounts were estimated. The results showed that the green seaweed species had the highest TAC content. In most of the studied algal species, the calculated ion quotient referred to their likelihood of overcoming high blood pressure. The estimated daily intake (EDI) of algae showed no adverse effects on human health. Most of the research variables are below the acceptable WHO/FAO level. Generally, the calorie content of the selected algae is less than 2 kcal, which makes the algae considered an alternative source of healthy food to reduce obesity.

关键词： Atherosclerosis   Coronary artery disease   Intravascular ultrasound   Endothelial shear stress   Near infrared spectroscopy   Vulnerable plaque   ENDOTHELIAL SHEAR-STRESS   NEAR-INFRARED SPECTROSCOPY   INTRAVASCULAR ULTRASOUND   NATURAL-HISTORY   ATHEROSCLEROSIS   INSIGHTS   HUMANS   SITES  

摘要： Background and aims: We aimed to characterize the spatial proximity of plaque destabilizing features local endothelial shear stress (ESS), minimal luminal area (MLA), plaque burden (PB), and near-infrared spectroscopy (NIRS) lipid signal in high-vs. low-risk plaques. Methods: Coronary arteries imaged with angiography and NIRS-intravascular ultrasound (IVUS) underwent 3D reconstruction and computational fluid dynamics calculations of local ESS. ESS, PB, MLA, and lipid core burden index (LCBI), for each 3-mm arterial segment were obtained in arteries with large lipid-rich plaque (LRP) vs. arteries with smaller LRP. The locations of the MLA, minimum ESS (minESS), maximum ESS (maxESS), maximum PB (maxPB), and maximum LCBI in a 4-mm segment (maxLCBI(4mm)) were determined along the length of each plaque. Results: The spatial distributions of minESS, maxESS, maxPB, and maxLCBI(4mm), in reference to the MLA, were significantly heterogeneous within and between each variable. The location of maxLCBI(4mm) was spatially discordant from sites of the MLA (p<0.0001), minESS (p = 0.003), and maxESS (p = 0.003) in arteries with large LRP (maxLCBI(4mm) >= 400) and non-large LRP. Large LRP arteries had higher maxESS (9.31 +/- 4.78 vs. 6.32 +/- 5.54 Pa; p = 0.023), lower minESS (0.41 +/- 0.16 vs. 0.61 +/- 0.26 Pa; p = 0.007), smaller MLA (3.54 +/- 1.22 vs. 5.14 +/- 2.65 mm(2); p = 0.002), and larger maxPB (70.64 +/- 9.95% vs. 56.70 +/- 13.34%, p<0.001) compared with non-large LRP arteries. Conclusions: There is significant spatial heterogeneity of destabilizing plaque features along the course of both large and non-large LRPs. Large LRPs exhibit significantly more abnormal destabilizing plaque features than non large LRPs. Prospective, longitudinal studies are required to determine which patterns of heterogeneous destabilizing features act synergistically to cause plaque destabilization.

关键词： Antioxidant   Osmolytes   Oxidative damage   Proline   Net CO2 assimilation   Stomatal conductance   WATERLOGGING STRESS TOLERANCE   PHYTOPHTHORA ROOT-ROT   NET GAS-EXCHANGE   GLUTATHIONE-REDUCTASE   PROLINE   MECHANISMS   SURVIVAL   EFFICACY   HYPOXIA   SPINACH  

摘要： In subtropical regions, low-chill stone fruit (Prunus spp.) crops have experienced the negative impacts of flooding caused by hurricanes and tropical storms. These crops are considered very susceptible to oxygen-deficient soil conditions resulting from flooding. We investigated physiological and biochemical responses to flooding of six Prunus spp. rootstocks including Flordaguard, are commonly used as a rootstock for peaches in the subtropics. Flooding caused a reduction in net CO2 assimilation (A), stomatal conductance (gs), and leaf nutrient contents in all rootstocks tested. Antioxidant activity, osmolyte concentrations, lipid peroxidation, and reactive oxygen species (ROS) activity increased in response to flooding in all rootstocks. After exposure to flooding, rootstocks MP-29 and R5064-5 had higher A, gs, antioxidant activities, and osmolyte concentration, and lower lipid peroxidation and ROS activity than the other rootstocks. These two rootstocks also had higher leaf nitrogen (N), phosphorous (P), and potassium (K) contents than the other rootstocks. Although leaf iron (Fe) and manganese (Mn) contents increased in all rootstocks exposed to flooding, MP-29 and R5064-5 exhibited the lowest increases in leaf Mn and Fe concentrations. Thus, rootstocks MP-29 and 5064-5 are better suited to subtropical areas prone to flooding than the other rootstocks, including Flordaguard. In the two rootstocks that were the most tolerant of flooding, greater antioxidant activities and osmolyte concentrations appeared to efficiently mitigate oxidative damage caused by oxygen deficiency. Also, osmolyte concentration and lipid peroxidation appear to be potential indicators of sensitivity to flooding stress in Prunus rootstocks.

关键词： Ecdysone receptor   Halloween genes   locust   Pergularia tomentosa   reproduction   retinoid‐X‐receptor   ENZYME-IMMUNOASSAY   ECDYSONE RECEPTOR   ESSENTIAL OILS   BIOSYNTHESIS   REPRODUCTION   CARDENOLIDES   EXTRACT   GENES   ECR  

摘要： Fractionation of the methanolic extract of Pergularia tomentosa, using column chromatography, resulted in the separation of 10 fractions and only the active one (that gave mortality >70%) was kept and denoted the active fraction (AFPt). Adult female Schistocerca gregaria were treated with two concentrations of AFPt, 0.24% and 0.96%, to investigate the effect on the female reproductive potential. Both concentrations of AFPt significantly increased the duration between adult emergence and first oviposition, as well as affected fecundity and fertility. Furthermore, the effects of AFPt on vitellogenesis and ecdysteroid titres were examined. Biochemical analyses revealed a significant decrease in protein, lipid and carbohydrate contents in ovaries. This study also showed that AFPt induced a significant decrease in the ovarian ecdysteroids levels, as well as the haemolymph ecdysteroid titres. The transcript levels of the ecdysteroid synthesis enzymes Spook and Shadow were significantly decreased when treated with the highest concentration of AFPt, while transcript levels of the ecdysteroid synthesis enzymes Phantom and Disembodied increased significantly in animals treated with AFPt. Treatment with AFPt also resulted in a significantly higher transcript level of both the ecdysone receptor (EcR) and its partner ultraspiracle/retinoid-X-receptor (USP/RXR).

关键词： Stevia rebaudiana   salicylic acid   yeast extract   steviol glycosides   gene expression   SALICYLIC-ACID   REBAUDIANA   CULTURES   BIOSYNTHESIS   ACCUMULATION   GLYCOSIDES   GROWTH   GENES  

摘要： Stevia rebaudiana Bert. is a medicinal plant used as a calorie-free sweetener due to the presence of steviol glycosides in its leaves. The present study evaluated morphological, biochemical, and molecular changes of stevia under salicylic acid (SA) elicitors (0, 25, 50, 75 and 100 mu M) and yeast extract (YE) (0, 1, 2, 3 and 5 g/L) under in vitro conditions. The results showed significant effects of elicitors on morphological traits and photosynthetic pigments of stevia. The highest morphological traits were observed at 25 mu M and control treatments of SA and YE respectively. On the other hand, increasing the concentrations of both elicitors resulted in lowered morphological traits. In general, plants treated with YE showed lowered growth, with the concentration rise lowering the growth further. HPLC results showed an increase in steviol glycosides content in 50 mu M SA and 2 g/L YE treatments and then the highest amount of stevioside and rebaudioside A was at concentrations of 25 mu M and 3 g/L. Investigation of expression levels of four genes (KA13H, UGT74G1, UGT76G1, and UGT85C2) indicated that the highest rate of expression occurred at the concentrations of 50 mu M SA and 2 g/L of YE. While, control treatment had the lowest levels expression of the studied genes in both elicitors, which indicates the significant effect of elicitors compared to the control. These results demonstrate the significant effect of SA and YE at medium concentrations on levels of expression of key genes of biosynthetic pathway as well as the production of stevioside and rebaudioside A. Thus, this approach could be employed to elevate the steviol glycosides' levels under in vitro conditions.

关键词： Heavy metal   Photosynthesis   Gene expression   Antagonism   Mineral nutrients   Physiological parameters   ASCORBATE PEROXIDASE   LEAD TOXICITY   ANTIOXIDANT MACHINERY   PLANT-RESPONSES   PHOTOSYSTEM-I   GAS-EXCHANGE   HEAVY-METALS   CADMIUM   STRESS   TOLERANCE  

摘要： Lead (Pb) is a highly toxic metal for humans, animals and plants even at low concentrations in the soil. The ingestion of chocolate produced from contaminated beans can contribute to consumer exposure to Pb. While, Mn is an element essential for plants and participates as enzymatic cofactors in several metabolic pathways. The objective of this study was to evaluate the influence of Mn on mitigation of Pb toxicity in seedling of the cacao clonal CCN 51 genotype grown in soils with different doses of Pb, Mn and Mn+Pb, through physiological, biochemical, molecular and nutritional responses. It was found that the seedling of the cacao clonal CCN 51 genotype grown in soils with high Pb, Mn and Mn+Pb contents accumulated these heavy metals in the roots and leaves. Mn doses reduced the Pb uptake by root system and prevented that the Pb accumulated at toxic levels in the roots and leaves of the plants. High doses of Pb applied in soil were highly toxic to the plants, leading, in some cases, them to death. However, no Mn toxicity was observed in cocoa plants, even at high doses in the soil. Uptake of Pb and Mn by the roots and its transport into the aerial part of the plant promoted changes in photosynthesis, leaf gas exchange, respiration, carboxylation and in the instantaneous efficiency of carboxylation, reducing in the treatments with the highest concentrations of Pb, and the emission of chlorophyll fluorescence, affecting the efficiency of photosystem 2 and the production of photoassimilates. Besides that, Pb, Mn and Mn+Pb toxicities activated defense mechanisms in plants that alter the gene expression of met, psbA and psbO, increasing in plants subjected to high concentrations of Pb and the activity of the enzymes involved in the cellular detoxification of excess ROS at the leaf level. In addition, high uptake of Mn by root system was found to reduced Pb uptake in plants grown with Mn+Pb in the soil. Therefore, application of Mn in the soil can be used to mitigate the

关键词： Superficial scald   Pear   Cold storage   Chilling injury   Ripening   Antioxidant content   ALPHA-FARNESENE   CONJUGATED TRIENOLS   GENE-EXPRESSION   FREEZING TOLERANCE   COLD-ACCLIMATION   APPLE   INHIBITION   STRESS   PEARS   1-METHYLCYCLOPROPENE  

摘要： The molecular and biochemical events underlying the onset of superficial scald in two pear cultivars with different susceptibility ('Blanquilla' and 'Conference') was investigated in fruit untreated and treated with lovastatin, 1-MCP or ethylene. 'Conference' pears were characterized by higher content of flavonols and linolenic acid (18:3), two metabolites related to chilling injury resistance. In this cultivar, the expression level of three genes belonging to the ascorbate glutathione pathway (APX, DHAR and MDHAR) were constitutively over expressed, highlighting the role that endogenous antioxidant potential played in scald control. In the scald-susceptible cultivar ('Blanquilla') the lovastatin treatment, in contrast to 1-MCP, effectively prevented superficial scald development and alpha-farnesene production without affecting fruit ripening. Moreover, lovastatin stimulated an increased production of ethanol and oleic + cis vaccenic acid (18:1), both compounds being also involved in cold stress tolerance. In both cultivars, and in contrast to 1-MCP, lovastatin did not impair the expression level of the genes devoted to ethylene production (ACO, ACS) and perception (ERS1, ERS2). As a consequence, the expression levels of the genes involved in texture modifications (PG1) and volatile emission (LOX, HPL, ADH and AAT) were maintained in lovastatin-treated samples allowing the fruit to reach an adequate final quality. The results from this study are discussed to highlight the complex regulatory network underlying superficial scald development in different pear cultivars.

关键词： Hexagonal boron nitride   Rat   Serum   Cytotoxicity   Oxidative stress   POTENTIAL APPLICATIONS   GLYCOL-CHITOSAN   NANOTUBES   TOXICITY   CYTOCOMPATIBILITY   BIOCOMPATIBILITY  

摘要： The aim of our study is to investigate the dose-dependent biological system effect of hexagonal boron nitride (hBN) nanoparticles, which is directly produced nanoscale, in vivo. Wistar albino rats (n = 80) weighing 200-250 g were divided into eight groups (n = 10). The acute effects of hBN NPs (i.v) on the rats were investigated by measuring the biochemical, hematological parameters and oxidant-antioxidant status. The results show that no significant change was observed in the hematological and biochemical parameters when the control group and other low dose groups were compared, except for the 1600 and 3200 mu g/kg b.w. dose groups. Histological detection indicated that 1600 and 3200 mu g/kg hBN NPs treatment could induce significant damage in the liver, kidney, heart, spleen and pancreas. With the findings obtained, it can be seen that hBN NPs cannot be evaluated independently of particle morphology, and that the hBN NPs used in this study may be suitable for biomedical applications where low doses between 50 and 800 mu g/kg are not toxic.

关键词： VDR polymorphisms   cardiometabolic disorders   vitamin D   Tetra ARMS PCR  

关键词： Raman spectroscopy   Bacteria chemistry   Discriminant analysis   Analysis of variance (ANOVA)   Partial least squares   RAPID IDENTIFICATION   ESCHERICHIA-COLI   VIBRATIONAL SPECTROSCOPY   RELEVANT MICROORGANISMS   SURFACE   TOOL   COMPONENTS   CELLS   MEDIA   SERS  

摘要： This study aimed to evaluate the differences in the Raman spectra of nine clinical species of bacteria isolated from infections (three Gram-positive and six Gram-negative species), correlating the spectra with the chemical composition of each species and to develop a classification model through discriminant analysis to categorize each bacterial strain using the peaks with the most significant differences. Bacteria were cultured in Mueller Hinton agar and a sample of biomass was harvested and placed in an aluminum sample holder. A total of 475 spectra from 115 different strains were obtained through a dispersive Raman spectrometer (830 nm) with exposure time of 50 s. The intensities of the peaks were evaluated by one-way analysis of variance (ANOVA) and the peaks with significant differences were related to the differences in the biochemical composition of the strains. Discriminant analysis based on quadratic distance applied to the peaks with the most significant differences and partial least squares applied to the whole spectrum showed 89.5% and 90.1% of global accuracy, respectively, for classification of the spectra in all the groups. Raman spectroscopy could be a promising technique to identify spectral differences related to the biochemical content of pathogenic microorganisms and to provide a faster diagnosis of infectious diseases.