Ketamine-induced loss of phenotype of fast-spiking interneurons is mediated by NADPH-oxidase   总被引：1，自引：0，他引：1  

Behrens MM  Ali SS  Dao DN  Lucero J  Shekhtman G  Quick KL  Dugan LL 《Science (New York, N.Y.)》2007,318(5856):1645-1647

Abuse of the dissociative anesthetic ketamine can lead to a syndrome indistinguishable from schizophrenia. In animals, repetitive exposure to this N-methyl-d-aspartate-receptor antagonist induces the dysfunction of a subset of cortical fast-spiking inhibitory interneurons, with loss of expression of parvalbumin and the gamma-aminobutyric acid-producing enzyme GAD67. We show here that exposure of mice to ketamine induced a persistent increase in brain superoxide due to activation in neurons of reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. Decreasing superoxide production prevented the effects of ketamine on inhibitory interneurons in the prefrontal cortex. These results suggest that NADPH oxidase may represent a novel target for the treatment of ketamine-induced psychosis.  相似文献   

Effect of a novel edible composite coating based on gum arabic and chitosan on biochemical and physiological responses of banana fruits during cold storage     

Maqbool M  Ali A  Alderson PG  Zahid N  Siddiqui Y 《Journal of agricultural and food chemistry》2011,59(10):5474-5482

The composite effects of gum arabic (GA) (5, 10, 15, and 20%) and chitosan (CH) (1.0%) on the biochemical and physiological characteristics of banana fruits stored at 13 ± 1 °C and 80 ± 3% relative humidity (RH) for 28 days and afterward for 5 days at simulated marketing conditions (25 °C, 60% RH) were investigated. Significant (P ≤ 0.05) differences were observed for the entire GA plus CH treatments as compared to the control. However, the results showed that after 33 days of storage, the weight loss and soluble solids concentration of fruits treated with 10% GA plus 1.0% CH composite coating were 24 and 54% lower, whereas fruit firmness, total carbohydrates, and reducing sugars were 31, 59, and 40% higher than the control, respectively. Furthermore, the composite edible coating of 10% GA plus 1.0% CH delayed color development and reduced the rate of respiration and ethylene evolution during storage as compared to the control. Similarly, sensory evaluation results also proved the effectiveness of 10% GA plus 1.0% CH composite coating by maintaining the overall quality of banana fruits. Consequently, the results of scanning electron microscopy also confirmed that the fruits coated with 10% GA plus 1.0% CH composite edible coating had very fewer cracks and showed a smooth surface. These findings suggest that 10% GA plus 1.0% CH as an edible composite coating can be used commercially for extending the storage life of banana fruits for up to 33 days.  相似文献   

Dicyandiamide increases the fertilizer N loss from an alkaline calcareous soil treated with <Superscript>15</Superscript>N-labelled urea under warm climate and under different crops     

Tariq Mahmood  Rehmat Ali  Zahid Latif  Wajid Ishaque 《Biology and Fertility of Soils》2011,47(6):619-631

Using an alkaline calcareous soil, experiments were conducted to elucidate the effects of nitrification inhibitor dicyandiamide (DCD) on the fate of ¹⁵N-labelled urea applied to cotton, maize, and wheat under greenhouse conditions. Combined effects of DCD and two levels of wheat straw (applied to cotton) and of fertilizer application method (conventional broadcast vs. point injection in maize and wheat) on the recovery of the fertilizer N were also studied. High soil temperatures prevailed under cotton and maize, whereas the soil temperature was relatively moderate during the wheat growing season. The fertilizer N loss under cotton was lowest (44% of the applied) when urea was applied alone; the loss increased due to DCD (54%) or wheat straw (50–54%) and was highest (63–64%) when DCD and wheat straw were applied together. Under maize also, DCD increased the loss of the fertilizer N applied by the conventional method (51% without DCD vs. 66% with DCD) or by point injection (26% without DCD vs. 42% with DCD). With the conventional method under wheat, DCD had no effect on the fertilizer N loss (34–37% of the applied). The fertilizer N loss under wheat was least (16%) when urea solution was point-injected but increased (24–26%) due to DCD or/and when pH of the urea solution was reduced to 2. Besides, DCD significantly reduced the fertilizer N uptake and increased the fertilizer N immobilization in soil under cotton and maize. However, DCD applied in combination with a higher level of wheat straw significantly increased the cotton dry matter and N yields due to increased N availability from sources other than the fertilizer. The results suggested that the use of DCD may not be beneficial in alkaline calcareous soils and that point injection of urea solution without any amendment is more effective in conserving the fertilizer N as compared to the conventional broadcast method.  相似文献   

Structure and physical properties of starch/poly vinyl alcohol/sodium montmorillonite nanocomposite films     

Ali SS  Tang X  Alavi S  Faubion J 《Journal of agricultural and food chemistry》2011,59(23):12384-12395

Nanocomposites of starch, poly vinyl alcohol (PVOH), and sodium montmorillonite (Na(+)MMT) were produced by solution mixing and cast into films. Tensile strength (TS) and elongation at the break (E%) of the films ranged from 11.60 to 22.35 MPa and 28.93-211.40%, respectively, while water vapor permeability (WVP) ranged from 0.718 to 1.430 g·mm/kPa·h·m(2). In general, an increase in Na(+)MMT content (0-20%) enhanced TS and decreased E% and WVP. Use of higher molecular weight PVOH increased both TS and E% and also decreased WVP. Mechanical properties were negatively affected, but water vapor barrier properties improved with increasing starch content (0-80%). X-ray diffraction and transmission electron microscopy were used to analyze the nanostructure, and molecular conformations and interactions in the multicomponent nanocomposites were inferred from glass transition behavior. Interactions between starch and PVOH were strongest, followed by polymer/clay interactions. On the basis of this insight, a conceptual model was presented to explain the phenomena of intercalation and exfoliation in the starch/PVOH/Na(+)MMT nanocomposites.  相似文献   

Supporting undergraduate research     

Ali F  Jadavji NM  Ong WC  Pandey KR  Patananan AN  Prabhala HK  Yang CH 《Science (New York, N.Y.)》2007,317(5834):42

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Reversal of bone loss in mice by nongenotropic signaling of sex steroids     

Kousteni S  Chen JR  Bellido T  Han L  Ali AA  O'Brien CA  Plotkin L  Fu Q  Mancino AT  Wen Y  Vertino AM  Powers CC  Stewart SA  Ebert R  Parfitt AM  Weinstein RS  Jilka RL  Manolagas SC 《Science (New York, N.Y.)》2002,298(5594):843-846

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Signal transduction and the control of gene expression   总被引：1，自引：0，他引：1  

Brivanlou AH  Darnell JE 《Science (New York, N.Y.)》2002,295(5556):813-818

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Subsurface radar sounding of the south polar layered deposits of Mars     

Plaut JJ  Picardi G  Safaeinili A  Ivanov AB  Milkovich SM  Cicchetti A  Kofman W  Mouginot J  Farrell WM  Phillips RJ  Clifford SM  Frigeri A  Orosei R  Federico C  Williams IP  Gurnett DA  Nielsen E  Hagfors T  Heggy E  Stofan ER  Plettemeier D  Watters TR  Leuschen CJ  Edenhofer P 《Science (New York, N.Y.)》2007,316(5821):92-95

The ice-rich south polar layered deposits of Mars were probed with the Mars Advanced Radar for Subsurface and Ionospheric Sounding on the Mars Express orbiter. The radar signals penetrate deep into the deposits (more than 3.7 kilometers). For most of the area, a reflection is detected at a time delay that is consistent with an interface between the deposits and the substrate. The reflected power from this interface indicates minimal attenuation of the signal, suggesting a composition of nearly pure water ice. Maps were generated of the topography of the basal interface and the thickness of the layered deposits. A set of buried depressions is seen within 300 kilometers of the pole. The thickness map shows an asymmetric distribution of the deposits and regions of anomalous thickness. The total volume is estimated to be 1.6 x 10(6) cubic kilometers, which is equivalent to a global water layer approximately 11 meters thick.  相似文献   

Antibody class switching mediated by yeast endonuclease-generated DNA breaks     

Zarrin AA  Del Vecchio C  Tseng E  Gleason M  Zarin P  Tian M  Alt FW 《Science (New York, N.Y.)》2007,315(5810):377-381

Antibody class switching in activated B cells uses class switch recombination (CSR), which joins activation-induced cytidine deaminase (AID)-dependent double-strand breaks (DSBs) within two large immunoglobulin heavy chain (IgH) locus switch (S) regions that lie up to 200 kilobases apart. To test postulated roles of S regions and AID in CSR, we generated mutant B cells in which donor Smu and accepter Sgamma1 regions were replaced with yeast I-SceI endonuclease sites. We found that site-specific I-SceI DSBs mediate recombinational IgH locus class switching from IgM to IgG1 without S regions or AID. We propose that CSR evolved to exploit a general DNA repair process that promotes joining of widely separated DSBs within a chromosome.  相似文献   

Strong, transparent, multifunctional, carbon nanotube sheets     

Zhang M  Fang S  Zakhidov AA  Lee SB  Aliev AE  Williams CD  Atkinson KR  Baughman RH 《Science (New York, N.Y.)》2005,309(5738):1215-1219

Individual carbon nanotubes are like minute bits of string, and many trillions of these invisible strings must be assembled to make useful macroscopic articles. We demonstrated such assembly at rates above 7 meters per minute by cooperatively rotating carbon nanotubes in vertically oriented nanotube arrays (forests) and made 5-centimeter-wide, meter-long transparent sheets. These self-supporting nanotube sheets are initially formed as a highly anisotropic electronically conducting aerogel that can be densified into strong sheets that are as thin as 50 nanometers. The measured gravimetric strength of orthogonally oriented sheet arrays exceeds that of sheets of high-strength steel. These nanotube sheets have been used in laboratory demonstrations for the microwave bonding of plastics and for making transparent, highly elastomeric electrodes; planar sources of polarized broad-band radiation; conducting appliqués; and flexible organic light-emitting diodes.  相似文献