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排序方式: 共有118条查询结果,搜索用时 15 毫秒
61.
Lobo MK Covington HE Chaudhury D Friedman AK Sun H Damez-Werno D Dietz DM Zaman S Koo JW Kennedy PJ Mouzon E Mogri M Neve RL Deisseroth K Han MH Nestler EJ 《Science (New York, N.Y.)》2010,330(6002):385-390
The nucleus accumbens is a key mediator of cocaine reward, but the distinct roles of the two subpopulations of nucleus accumbens projection neurons, those expressing dopamine D1 versus D2 receptors, are poorly understood. We show that deletion of TrkB, the brain-derived neurotrophic factor (BDNF) receptor, selectively from D1+ or D2+ neurons oppositely affects cocaine reward. Because loss of TrkB in D2+ neurons increases their neuronal excitability, we next used optogenetic tools to control selectively the firing rate of D1+ and D2+ nucleus accumbens neurons and studied consequent effects on cocaine reward. Activation of D2+ neurons, mimicking the loss of TrkB, suppresses cocaine reward, with opposite effects induced by activation of D1+ neurons. These results provide insight into the molecular control of D1+ and D2+ neuronal activity as well as the circuit-level contribution of these cell types to cocaine reward. 相似文献
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63.
Suvra Mandal Anupam Nayak Manoj Kar Samir K. Banerjee Ashes Das S.N. Upadhyay R.K. Singh Avijit Banerji Julie Banerji 《Fitoterapia》2010
The bioassay guided fractionation of the n-hexane extract of the seeds of Murraya koenigii Spreng (Rutaceae) resulted in the isolation of three bioactive carbazole alkaloids, kurryam (I), koenimbine (II) and koenine (III). The structures of the compounds were confirmed from their 1H-, 13C-, and 2D-NMR spectral data. Of the three compounds (I) and (II) exhibited significant inhibitory activity against castor oil-induced diarrhoea and PGE2-induced enteropooling in rats. The compounds also produced a significant reduction in gastrointestinal motility in the charcoal meal test in Wister rats. 相似文献
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A radical scavenging guided phytochemical study on the stem bark of Tecoma mollis afforded seven active phenylpropanoid glycosides (1–7), including a new one (4), and one iridoid (8). The structures of the isolated compounds were elucidated on the basis of spectroscopic evidences and correlated with known compounds. Compounds (1–7) displayed promising antioxidant activity (DPPH assay) in relation to ascorbic acid (positive control). The antimicrobial activity for compounds (1–8) was evaluated against five bacterial and five fungal strains. The isolated compounds exhibited nonselective weak to moderate antimicrobial activity. The highest antileishmanial activity against Leishmania donovani was observed for compound (7) with an IC50 value of 6.71 μg/ml, using pentamidine and amphotericin B as drug controls. Compound (5) exhibited moderate antimalarial activity (45% inhibition) against chloroquine sensitive (D6) clones of Plasmodium falciparum. 相似文献
66.
Environmental arsenic (As) contamination, considered as the largest mass poisoning of the human population, has become a serious health concern for the people of South East Asia, including those living in the Bengal delta. An As-resistant strain, KUMAs15, was isolated from the As-contaminated fields in Nadia Ddistrict in West Bengal, India and was evaluated for its possible use in environmental As bioremediation. Molecular identification based on 16S rDNA gene sequencing revealed that the strain belonged to the genus Micrococcus. The strain tolerated high levels of As and oxidized arsenite under the culture condition. The strain also accumulated large quantities of As when exposed to a wide range of environmentally relevant concentrations of inorganic As. Analysis of the aoxB, arsB, and arsC gene expression explained the underlying cause of arsenite oxidation and As accumulation by KUMAs15. The As-resistant strain KUMAs15 of Micrococcus sp. was suggested to be a potential environmental As decontaminant. 相似文献
67.
Quantification of nasal airflow resistance in English bulldogs using computed tomography and computational fluid dynamics
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Eric T. Hostnik Brian A. Scansen Rachel Zielinski Samir N. Ghadiali 《Veterinary radiology & ultrasound》2017,58(5):542-551
Stenotic nares, edematous intranasal turbinates, mucosal swelling, and an elongated, thickened soft palate are common sources of airflow resistance for dogs with brachycephalic airway syndrome. Surgery has focused on enlarging the nasal apertures and reducing tissue of the soft palate. However, objective measures of surgical efficacy are lacking. Twenty‐one English bulldogs without previous surgery were recruited for this prospective, pilot study. Computed tomography was performed using conscious sedation and without endotracheal intubation using a 128 multidetector computed tomography scanner. Raw multidetector computed tomography data were rendered to create a three‐dimensional surface mesh model by automatic segmentation of the air‐filled nasal passage from the nares to the caudal soft palate. Three‐dimensional surface models were used to construct computational fluid dynamics models of nasal airflow resistance from the nares to the caudal aspect of the soft palate. The computational fluid dynamics models were used to simulate airflow in each dog and airway resistance varied widely with a median 36.46 (Pa/mm)/(l/s) and an interquartile range of 19.84 to 90.74 (Pa/mm)/(/s). In 19/21 dogs, the rostral third of the nasal passage exhibited a larger airflow resistance than the caudal and middle regions of the nasal passage. In addition, computational fluid dynamics data indicated that overall measures of airflow resistance may significantly underestimate the maximum local resistance. We conclude that computational fluid dynamics models derived from nasal multidetector computed tomography can quantify airway resistance in brachycephalic dogs. This methodology represents a novel approach to noninvasively quantify airflow resistance and may have utility for objectively studying effects of surgical interventions in canine brachycephalic airway syndrome. 相似文献
68.
Afandi Imane Talba Sophia Benhra Ali Benbrahim Samir Chfiri Rachid Labonne Maylis Masski Hicham Laë Raymond Tito De Morais Luis Bekkali Mohammed Bouthir Fatima Zohra 《International Aquatic Research》2018,10(2):191-205
International Aquatic Research - In the current study, ten elements contents (Fe, Zn, Mn, Cu, Cr, Co, Ni, Cd, Pb and Hg) have been measured in muscle and liver of four pelagic fish species... 相似文献
69.
Solid-substrate fermentation of corn fiber by Phanerochaete chrysosporium and subsequent fermentation of hydrolysate into ethanol 总被引:2,自引:0,他引:2
Shrestha P Rasmussen M Khanal SK Pometto AL van Leeuwen JH 《Journal of agricultural and food chemistry》2008,56(11):3918-3924
The goal of this study was to develop a fungal process for ethanol production from corn fiber. Laboratory-scale solid-substrate fermentation was performed using the white-rot fungus Phanerochaete chrysosporium in 1 L polypropylene bottles as reactors via incubation at 37 degrees C for up to 3 days. Extracellular enzymes produced in situ by P. chrysosporium degraded lignin and enhanced saccharification of polysaccharides in corn fiber. The percentage biomass weight loss and Klason lignin reduction were 34 and 41%, respectively. Anaerobic incubation at 37 degrees C following 2 day incubation reduced the fungal sugar consumption and enhanced the in situ cellulolytic enzyme activities. Two days of aerobic solid-substrate fermentation of corn fiber with P. chrysosporium, followed by anaerobic static submerged-culture fermentation resulted in 1.7 g of ethanol/100 g of corn fiber in 6 days, whereas yeast ( Saccharomyces cerevisiae) cocultured with P. chrysosporium demonstrated enhanced ethanol production of 3 g of ethanol/100 g of corn fiber. Specific enzyme activity assays suggested starch and hemi/cellulose contribution of fermentable sugar. 相似文献
70.
King ES Swiegers JH Travis B Francis IL Bastian SE Pretorius IS 《Journal of agricultural and food chemistry》2008,56(22):10829-10837
Alcoholic fermentation using Saccharomyces wine yeast is an effective means of modulating wine aroma. This study investigated the impact of coinoculating commercial yeast strains (Vin7, QA23, Vin13) on the volatile composition and sensory profile of Sauvignon Blanc wines. Small-scale replicated fermentations were conducted using single-strain and coinoculations of Vin7 with QA23 and with Vin13. The results showed that the chemical and sensory profiles of the coinoculated wines were different from both the single-strain wines and equal blends of the single-strain wines. Volatile thiol analysis indicated that the Vin7/QA23 coinoculated wines were highest in 3-mercaptohexan-1-ol (3MH) and 3-mercaptohexyl acetate (3MHA), although this pattern was not observed for the Vin7/Vin13 yeast combination. The negative white vinegar aroma and high volatile acidity measured in the Vin7 single-strain wines were not present in the coinoculated wines. This study demonstrates that coinoculations can modify the aroma profile of wines, when complementary yeasts are used. 相似文献