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11.
Delayed sleep phase disorder (DSPD) is assumed to be common amongst adolescents, with potentially severe consequences in terms of school attendance and daytime functioning. The most common treatment approaches for DSPD are based on the administration of bright light and/or exogenous melatonin with or without adjunct behavioural instructions. Much is generally known about the chronobiological effects of light and melatonin. However, placebo-controlled treatment studies for DSPD are scarce, in particular in adolescents and young adults, and no standardized guidelines exist regarding treatment. The aim of the present study was, therefore, to investigate the short- and long-term effects on sleep of a DSPD treatment protocol involving administration of timed bright light and melatonin alongside gradual advancement of rise time in adolescents and young adults with DSPD in a randomized controlled trial and an open label follow-up study. A total of 40 adolescents and young adults (age range 16–25 years) diagnosed with DSPD were recruited to participate in the study. The participants were randomized to receive treatment for two weeks in one of four treatment conditions: dim light and placebo capsules, bright light and placebo capsules, dim light and melatonin capsules or bright light and melatonin capsules. In a follow-up study, participants were re-randomized to either receive treatment with the combination of bright light and melatonin or no treatment in an open label trial for approximately three months. Light and capsules were administered alongside gradual advancement of rise times. The main end points were sleep as assessed by sleep diaries and actigraphy recordings and circadian phase as assessed by salivary dim light melatonin onset (DLMO). During the two-week intervention, the timing of sleep and DLMO was advanced in all treatment conditions as seen by about 1?h advance of bed time, 2?h advance of rise time and 2?h advance of DLMO in all four groups. Sleep duration was reduced with approximately 1?h. At three-month follow-up, only the treatment group had maintained an advanced sleep phase. Sleep duration had returned to baseline levels in both groups. In conclusion, gradual advancement of rise time produced a phase advance during the two-week intervention, irrespective of treatment condition. Termination of treatment caused relapse into delayed sleep times, whereas long-term treatment with bright light and melatonin (three months) allowed maintenance of the advanced sleep phase.  相似文献   
12.
d-Galactose is widely used as an agent to cause aging effects in experimental animals. The present study aims to investigate the effects of hydrogen sulfide (H2S) in human neuroblastoma SH-SY5Y cells exposed to d-galactose. Cells were pretreated with NaHS, an H2S donor, and then exposed to d-galactose (25–400 mM for 48 h). We found that NaHS pretreatment significantly reversed the d-galactose-induced cell death and cellular senescence. MTT assay shows that NaHS significantly increased cell viability from 62.31 ± 1.29% to 72.34 ± 0.46% compared with d-galactose (200 mM) treatment group. The underlying mechanism appeared to involve a reduction by NaHS in the formation of advanced glycation end products (AGEs), which are known to contribute to the progression of age-related diseases. In addition, NaHS decreased the elevation of reactive oxygen species from 151.17 ± 2.07% to 124.8 ± 2.89% and malondialdehyde from 1.72 ± 0.07 to 1.10 ± 0.08 (nmol/mg protein) in SH-SY5Y cells after d-galactose exposure. NaHS also stimulated activities of superoxide dismutase from 0.42 ± 0.05 to 0.73 ± 0.04 (U/mg protein) and glutathione peroxidase from 3.98 ± 0.73 to 14.73 ± 0.77 (nmol/min/mg protein) and upregulated the gene expression levels of copper transport protein ATOX1, glutathione synthetase (GSS) and thioredoxin reductase 1 (TXNRD1) while down-regulated aldehyde oxidase 1 (AOX1). In summary, our data indicate that H2S may have potentially anti-aging effects through the inhibition of AGEs formation and reduction of oxidative stress.  相似文献   
13.
Pyruvate carboxylase (PC) is a biotin-dependent enzyme that catalyzes the MgATP- and bicarbonate-dependent carboxylation of pyruvate to oxaloacetate, an important anaplerotic reaction in central metabolism. The carboxyltransferase (CT) domain of PC catalyzes the transfer of a carboxyl group from carboxybiotin to the accepting substrate, pyruvate. It has been hypothesized that the reactive enolpyruvate intermediate is stabilized through a bidentate interaction with the metal ion in the CT domain active site. Whereas bidentate ligands are commonly observed in enzymes catalyzing reactions proceeding through an enolpyruvate intermediate, no bidentate interaction has yet been observed in the CT domain of PC. Here, we report three X-ray crystal structures of the Rhizobium etli PC CT domain with the bound inhibitors oxalate, 3-hydroxypyruvate, and 3-bromopyruvate. Oxalate, a stereoelectronic mimic of the enolpyruvate intermediate, does not interact directly with the metal ion. Instead, oxalate is buried in a pocket formed by several positively charged amino acid residues and the metal ion. Furthermore, both 3-hydroxypyruvate and 3-bromopyruvate, analogs of the reaction product oxaloacetate, bind in an identical manner to oxalate suggesting that the substrate maintains its orientation in the active site throughout catalysis. Together, these structures indicate that the substrates, products and intermediates in the PC-catalyzed reaction are not oriented in the active site as previously assumed. The absence of a bidentate interaction with the active site metal appears to be a unique mechanistic feature among the small group of biotin-dependent enzymes that act on α-keto acid substrates.  相似文献   
14.
3-Isobutyroxy-β-ionone (III) is the proposed structure of quiesone, the naturally occurring inhibitor of the germination of Peronospora tabacina conidia. This was synthesized as a racemate and shown to possess qualitatively identical biological activity as quiesone itself. Employing an intermediate of this synthesis, dl-dehydrovomifoliol (VII) was also synthesized.  相似文献   
15.
The effect of amino acid composition on the conversion ratio of tryptophan to nicotinamide was investigated. The ratio in the group fed with an amino acid diet simulating rice protein was around 2.5%. This ratio was statistically decreased by the addition of the limiting amino acids, except for tryptophan, and increased by the addition of all the limiting amino acids, including tryptophan. The composition of amino acids proved to greatly affect the conversion ratio.  相似文献   
16.
Glyceraldehyde (200 mM) and Nα-acetyllysine (100 mM) were incubated in 0.2 M sodium phosphate buffer (pH 7.4) at 37°C for a week. A major compound, glyceraldehyde-related Maillard reaction product, was purified from the reaction mixture using reverse phase (ODS)-HPLC. It was identified as 1-(5-acetylamino-5-carboxypentyl)-3-hydroxy-5-hydroxymethyl-pyridinium, named as GLAP (Glyceraldehyde derived Pyridinium compound), using NMR and MS analyses. It was suggested that GLAP as a novel advanced glycation end product (AGE) is one of the key compounds in the glyceraldehyde-related Maillard reaction.  相似文献   
17.
Accumulation evidence shows that β-amyloid (Aβ) is a neurotoxic and accumulation of Aβ is responsible for the pathology of Alzheimer''s disease (AD). However, it is currently not fully understood what makes Aβ toxic and accumulated. Previous studies demonstrate that Aβ is a suitable substrate for glycation, producing one form of the advanced glycation endproducts (AGEs). We speculated that Aβ-AGE formation may exacerbate the neurotoxicity. To explore whether the Aβ-AGE is more toxic than the authentic Aβ and to understand the molecular mechanisms, we synthesized glycated Aβ by incubating Aβ with methylglyoxal (MG) in vitro and identified the formation of glycated Aβ by fluorescence spectrophotometer. Then, we treated the primary hippocampal neurons cultured 8 days in vitro with Aβ-AGE or Aβ for 24 h. We observed that glycation exacerbated neurotoxicity of Aβ with upregulation of receptor for AGE (RAGE) and activation of glycogen synthase kinase-3 (GSK-3), whereas simultaneous application of RAGE antibody or GSK-3 inhibitor reversed the neuronal damages aggravated by glycated Aβ. Thereafter, we found that Aβ is also glycated with an age-dependent elevation of AGEs in Tg2576 mice, whereas inhibition of Aβ-AGE formation by subcutaneously infusion of aminoguanidine for 3 months significantly rescued the early cognitive deficit in mice. Our data reveal for the first time that the glycated Aβ is more toxic. We propose that the glycated Aβ with the altered secondary structure may be a more suitable ligand than Aβ for RAGE and subsequent activation of GSK-3 that can lead to cascade pathologies of AD, therefore glycated Aβ may be a new therapeutic target for AD.  相似文献   
18.
Pro‐aging effects of endogenous advanced glycation end‐products (AGEs) have been reported, and there is increasing interest in the pro‐inflammatory and ‐fibrotic effects of their binding to RAGE (the main AGE receptor). The role of dietary AGEs in aging remains ill‐defined, but the predominantly renal accumulation of dietary carboxymethyllysine (CML) suggests the kidneys may be particularly affected. We studied the impact of RAGE invalidation and a CML‐enriched diet on renal aging. Two‐month‐old male, wild‐type (WT) and RAGE?/? C57Bl/6 mice were fed a control or a CML‐enriched diet (200 μg CML/gfood) for 18 months. Compared to controls, we observed higher CML levels in the kidneys of both CML WT and CML RAGE?/? mice, with a predominantly tubular localization. The CML‐rich diet had no significant impact on the studied renal parameters, whereby only a trend to worsening glomerular sclerosis was detected. Irrespective of diet, RAGE?/? mice were significantly protected against nephrosclerosis lesions (hyalinosis, tubular atrophy, fibrosis and glomerular sclerosis) and renal senile apolipoprotein A‐II (ApoA‐II) amyloidosis (p < 0.001). A positive linear correlation between sclerosis score and ApoA‐II amyloidosis score (r = 0.92) was observed. Compared with old WT mice, old RAGE?/? mice exhibited lower expression of inflammation markers and activation of AKT, and greater expression of Sod2 and SIRT1. Overall, nephrosclerosis lesions and senile amyloidosis were significantly reduced in RAGE?/? mice, indicating a protective effect of RAGE deletion with respect to renal aging. This could be due to reduced inflammation and oxidative stress in RAGE?/? mice, suggesting RAGE is an important receptor in so‐called inflamm‐aging.  相似文献   
19.
This study assesses crop residues in the EU from major crops using empirical models to predict crop residues from yield statistics; furthermore it analyses the inter‐annual variability of those estimates over the period 1998‐2015, identifying its main drivers across Europe. The models were constructed based on an exhaustive collection of experimental data from scientific papers for the crops: wheat, barley, rye, oats, triticale, rice, maize, sorghum, rapeseed, sunflower, soybean, potato and sugarbeet. We discuss the assumptions on the relationship between yield and the harvest index, adopted by previous studies, to interpret the experimental data, quantify the uncertainties of these models, and establish the premises to implement them at regional scale –i.e., NUTS level 3– within the EU. To cope this, we created a consolidated sub‐national statistical data along with an algorithm able to aggregate (figures are provided at country level) and disaggregate (production at 25 km grid is provided assupplementary material) estimates. The total lignocellulosic biomass production in the EU28 over the review period, according to our models, is 419 Mt, from which wheat is the major contributor (155 Mt). Our results show that maize and rapeseed are the two crops with the highest residue yield, respectively 8.9 and 8.6 t ha‐1. The spatial analysis revealed that these three crops, which, according to our results, are feedstocks highly suitable a priori for second generation biofuels in the EU and are unevenly distributed across Europe. Weather fluctuation was identified as the major driver in residue production from cereals, while, in the case of starch crops and oilseeds – which are predominant in northern Europe – corresponded to the marked production trend likely influenced by the agricultural policies and agro‐management over the review period. Our results, among others, could help to understand and quantify the ecological boundaries of the bioeconomy from agriculture.  相似文献   
20.
With the recent development of genomic resources and high‐throughput phenotyping platforms, the 21st century is primed for major breakthroughs in the discovery, understanding and utilization of plant genetic variation. Significant advances in agriculture remain at the forefront to increase crop production and quality to satisfy the global food demand in a changing climate all while reducing the environmental impacts of the world's food production. Sorghum, a resilient C4 grain and grass important for food and energy production, is being extensively dissected genetically and phenomically to help connect the relationship between genetic and phenotypic variation. Unlike genetically modified crops such as corn or soybean, sorghum improvement has relied heavily on public research; thus, many of the genetic resources serve a dual purpose for both academic and commercial pursuits. Genetic and genomic resources not only provide the foundation to identify and understand the genes underlying variation, but also serve as novel sources of genetic and phenotypic diversity in plant breeding programs. To better disseminate the collective information of this community, we discuss: (i) the genomic resources of sorghum that are at the disposal of the research community; (ii) the suite of sorghum traits as potential targets for increasing productivity in contrasting environments; and (iii) the prospective approaches and technologies that will help to dissect the genotype–phenotype relationship as well as those that will apply foundational knowledge for sorghum improvement.  相似文献   
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