青稞酒酿造中稻壳精选清蒸工艺的研究

在青稞酒生产中,辅料稻壳质量的好坏及清蒸效果直接影响青稞酒的质量。稻壳在参与发酵的过程中会产生糠醛,糠醛是白酒中的呈香物质,能赋予白酒以特殊的香味,但含量过高会使白酒产生糠霉味、燥辣味,从而影响青稞酒的质量。通过精选清蒸的方法水解稻壳中一部分的多缩戊糖,经过处理的稻壳参与青稞酒发酵,最终利用气相色谱-质谱联用仪进行分析原酒中的糠醛含量的变化。     

Screening a peptidyl database for potential ligands to proteins with side-chain flexibility

OBJECTIVE: Microdialysis and 31P-NMR spectroscopy were used to test opposing hypotheses that ischemic preconditioning inhibits adenine nucleotide degradation and purine efflux, or that preconditioning activates cardiovascular adenosine formation to provide enhanced cardioprotection. METHODS: 31P-NMR spectra and matching interstitial fluid (ISF) or venous effluent samples were obtained from Langendorff perfused rat hearts. Control hearts (n = 9) underwent 30 min of global normothermic ischemia and 30 min reperfusion. Preconditioned hearts (n = 6) were subjected to a 5 min ischemic episode and 10 min reflow prior to 30 min ischemia and 30 min reperfusion. Effects of repetitive ischemia-reperfusion (3 x 5 min ischemic episodes) on adenosine levels and energy metabolism were also assessed (n = 8). RESULTS: Preconditioning improved post-ischemic recovery of heart rate x left ventricular developed pressure (71 +/- 5 vs 43 +/- 8%, P < 0.05) and end-diastolic pressure (14 +/- 3 vs 29 +/- 4 mmHg, P < 0.05) compared with control hearts, respectively. Preconditioning did not alter intracellular ATP, phosphocreatine (PCr), inorganic phosphate (Pi), H+ or free Mg2+ during global ischemia, but improved recoveries of PCr, Pi, and delta GATP on reperfusion. ISF adenosine increased more than 20-fold during 30 min ischemia. The 5 min preconditioning episode increased ISF adenosine 3-fold, and reduced ISF adenosine and inosine during subsequent prolonged ischemia by up to 75%. Venous purine levels during reperfusion were also reduced by preconditioning. Accumulation of adenosine in ISF and venous effluent during repetitive ischemia was progressively reduced despite comparable changes in substrate for adenosine formation via 5'-nucleotidase, (5'-AMP), and in allosteric modulators of this enzyme (Mg2+, H+, Pi, ADP, ATP). CONCLUSIONS: (i) Ischemic preconditioning reduces interstitial and vascular adenosine levels during ischemia-reperfusion, (ii) reduced ISF adenosine during ischemia is not due to reduced ischemic depletion of adenine nucleotides in preconditioned rat hearts, (iii) preconditioning may inhibit adenosine formation via 5'-nucleotidase in ischemic rat hearts, and (iv) improved functional recovery with preconditioning is unrelated to metabolic/bioenergetic changes during the ischemic insult, but may be related to improved post-ischemic recovery of [Pi] and delta GATP in this model.     

trans-3-Benzyl-4-hydroxy-7-chromanylbenzoic acid derivatives as antagonists of the leukotriene B4 (LTB4) receptor

The SAR of a series of 2-(7-chromanyl)benzoic acids has been investigated with the aim of identifying potent and selective LTB4 receptor antagonists that maintain potency in complex biological fluids. We found optimal activity in derivatives with electron-withdrawing groups in the benzoic acid ring and with an unsubstituted C-3 benzyl group on the chromanol nucleus. While compounds containing a 3-(4-phenyl)benzyl chromanol substituent were potent LTB4 receptor antagonists, the increased lipophilicity imparted by the additional phenyl substituent led to decreased potency in the presence of plasma proteins. From among the potent compounds identified, CP-195543, the 5'-trifluoromethyl 3-benzyl chromanol, was selected for development.     

Sertindole, a new atypical antipsychotic for the treatment of schizophrenia

Recent studies have shown that at least some of the functional effects of serotonin (5-HT) on motoneuron excitability are direct and are mediated via postsynaptic 5-HT receptors on motoneurons. To determine the spatial distribution of direct inputs from the serotonin system on the proximal and distal dendrites of individual motoneurons, we examined identified motoneurons in vivo with a combination of immunohistochemical localization of 5-HT-immunoreactive boutons and intracellular staining with horseradish peroxidase. Seventeen intracellularly stained motoneurons from 12 adult cats were analyzed with light microscopy. Quantitative analysis of 5-HT boutons apposed to dendrites of five representative motoneurons that were entirely reconstructed in three dimensions (each from the lumbosacral spinal cord of a different animal) revealed a total of 7,848 contacts (1,570+/-487 contacts/postsynaptic neuron; mean +/- SD) over the dendrites of these cells. Analysis of contacts on the soma of two of these cells, and on the somas of an additional 12 intracellularly stained motoneurons, revealed a wide range of somatic contacts (11-211 contacts/cell) on motoneuron cell bodies, with an average of 52 contacts/cell. These results indicate that the vast majority of 5-HT-immunoreactive boutons are apposed to dendritic branches rather than to the somatic surface of motoneurons. The spatial distribution of contacts essentially matched the distribution of surface membrane area of the postsynaptic neuron, resulting in a relatively uniform density of contacts (<1/100 microm2) on proximal and distal dendrites. Consequently, the frequency of contacts was higher on the proximal dendritic compartments where available membrane area is greater. There was no preferential distribution of contacts to particular dendrites. Light/electron microscopic correlations were performed on 21 boutons that contacted dendrites (n = 7) of three motoneurons from different animals. At the electron microscope level, most appositions (18/21; 85.7%) selected by our light microscopic criteria were confirmed as direct contacts when the 5-HT boutons were examined through serial sections. Synaptic junctions, generally small and symmetric, were positively identified in only a subset of these cases (n = 6; 28.6%), in part due to the obscuring effects of the peroxidase histochemical precipitate present in both pre- and postsynaptic profiles. A few 5-HT boutons (3/21; 14.3%) selected as contacts by our light microscopic criteria were in fact separated from the adjacent labeled dendrites; in two of these three cases, the separation was due to intrusion of very thin glial lamellae (<0.3 microm in cross section). These results indicate that the bulbospinal serotonergic system(s) provide a significant, direct synaptic input to spinal motoneurons that innervate hindlimb muscles. The nature of the modulatory actions exerted by such widespread synaptic inputs will affect all regions of the somatodendritic membrane and will ultimately depend on the nature of the 5-HT receptors present over different parts of the postsynaptic neuron's dendritic tree.     

Magnesium supplementation alleviates premenstrual symptoms of fluid retention

We investigated the effect of a daily supplement of 200 mg of magnesium (as MgO) for two menstrual cycles on the severity of premenstrual symptoms in a randomized, double-blind, placebo-controlled, crossover study. A daily supplement of 200 mg of Mg (as MgO) or placebo was administered for two menstrual cycles to each volunteer, who kept a daily record of her symptoms, using a 4-point scale in a menstrual diary of 22 items. Symptoms were grouped into six categories: PMS-A (anxiety), PMS-C (craving), PMS-D (depression), PMS-H (hydration), PMS-O (other), and PMS-T (total overall symptoms). Urinary Mg output/24 hours was estimated from spot samples using the Mg/creatinine ratio. Analysis of variance for 38 women showed no effect of Mg supplementation compared with placebo in any category in the first month of supplementation. In the second month there was a greater reduction (p = 0.009) of symptoms of PMS-H (weight gain, swelling of extremities, breast tenderness, abdominal bloating) with Mg supplementation compared with placebo. Compliance to supplementation was confirmed by the greater mean estimated 24-hour urinary output of Mg (p = 0.013) during Mg supplementation (100.8 mg) compared with placebo (74.1 mg). A daily supplement of 200 mg of Mg (as MgO) reduced mild premenstrual symptoms of fluid retention in the second cycle of administration.     

An Ultraflexible and Stretchable Aptameric Graphene Nanosensor for Biomarker Detection and Monitoring

An ultraflexible and stretchable field‐effect transistor nanosensor is presented that uses aptamer‐functionalized monolayer graphene as the conducting channel. Specific binding of the aptamer with the target biomarker induces a change in the carrier concentration of the graphene, which is measured to determine the biomarker concentration. Based on a Mylar substrate that is only 2.5‐µm thick, the nanosensor is capable of conforming to underlying surfaces (e.g., those of human tissue or skin) that undergo large bending, twisting, and stretching deformations. In experimental testing, the device is rolled on cylindrical surfaces with radii down to 40 µm, twisted by angles ranging from ?180° to 180°, or stretched by extensions up to 125%. With these large deformations applied either cyclically or non‐recurrently, the device is shown to incur no visible mechanical damage, maintain consistent electrical properties, and allow detection of TNF‐α, an inflammatory cytokine biomarker, with consistently high selectivity and low limit of detection (down to 5 × 10^?12 m ). The nanosensor can thus potentially enable consistent and reliable detection of liquid‐borne biomarkers on human skin or tissue surfaces that undergo large mechanical deformations.     

Nutritional composition,fatty acid profile,phytochemistry and evaluation of the effects of Carya illinoinensis on diabetes

The increase in chronic diseases has arisen interest to search for alternative treatments so that people can improve their quality of life. Thus, Carya illinoinensis is the subject of the present work which aims at determining whether it has antidiabetic activity. The plant was collected and its nuts were separated from their peels, dried and grinded and incorporated into the feed, in concentration of 6% and 10%, for the treatment of animals. The centesimal composition of this diet was also determined. From the nut was also obtained the fixed oil, for the profile of fatty acids, and the 70% hydroethanolic extract for the phytochemical analysis. The results have shown that species presents hypoglycaemic effect, high fat composition of unsaturated fatty acids and the presence of some phenolic compounds, directly related to the antidiabetic activity. Therefore, the specie presente benefits that can contribute to the binomial diet/health.     

The use of 2D NMR to study β-cyclodextrin complexation and debittering of amino acids and peptides

This work fully demonstrated the formation of amino acids complexes with β-cyclodextrin (β-CD) by the method of nuclear magnetic resonance with the rotating frame Overhauser effect spectroscopy (ROESY) and diffusion ordered spectroscopy (DOSY) techniques. The tested amino acids display the following decreasing order of affinity for β-CD: tryptophane > tyrosine > phenylalanine > proline > histidine > isoleucine. The influence of complexation on taste perception was determined with a trained panel to qualify taste alterations of single amino acids and quantify the debittering of soy protein hydrolysate by β-CD complexation. The results showed that β-CD complexation is effective for modifying single amino acids taste perception and debittering soy protein hydrolysate. Bitterness sensation of the latter is reduced by 90% when 5% β-CD was added, thus β-CD is recommended as a prospective additive for masking bitter taste of new functional food products.     

Sex ratio and parental age gap

We compare the physicochemical and functional characteristics of nucleoplasmin obtained from Xenopus laevis oocytes and by bacterial overexpression of a plasmid containing the nucleoplasmin gene. The comparison shows that, while the secondary structure of the protein is not affected by the method used to obtain this protein, the bacterial expressed form exhibits a marked tendency to form large aggregates and an impaired ability to displace protamines from sperm nuclei. These results add a word of caution to the indiscriminate use, in functional or structural (crystallographic) studies, of bacterially overproduced proteins that have been end-terminally tagged with polyhistidine.