Detecting and quantifying sunflower oil adulteration in extra virgin olive oils from the eastern mediterranean by visible and near-infrared spectroscopy   总被引：1，自引：0，他引：1  

Downey G  McIntyre P  Davies AN 《Journal of agricultural and food chemistry》2002,50(20):5520-5525

One hundred and thirty-eight oil samples have been analyzed by visible and near-infrared transflectance spectroscopy. These comprised 46 pure extra virgin olive oils and the same oils adulterated with 1% (w/w) and 5% (w/w) sunflower oil. A number of multivariate mathematical approaches were investigated to detect and quantify the sunflower oil adulterant. These included hierarchical cluster analysis, soft independent modeling of class analogy (SIMCA method), and partial least squares regression (PLS). A number of wavelength ranges and data pretreatments were explored. The accuracy of these mathematical models was compared, and the most successful models were identified. Complete classification accuracy was achieved using 1st derivative spectral data in the 400-2498 nm range. Prediction of adulterant content was possible with a standard error equal to 0.8% using 1st derivative data between 1100 and 2498 nm. Spectral features and chemical literature were studied to isolate the structural basis for these models.  相似文献   

Pharmacokinetics,efficacy and convulsive dose of articaine hydrochloride in goat kids     

Dinakaran Venkatachalam  John Paul Chambers  Kavitha Kongara  Neil Ward  Antony Jacob  Preet Mohinder Singh 《Veterinary anaesthesia and analgesia》2021,48(2):264-271

ObjectiveTo investigate the pharmacokinetics, efficacy and convulsive dose of articaine hydrochloride in goat kids.Study designExperimental prospective study.AnimalsA total of 18 (n = 6 animals per experiment) male Saanen goat kids (2–4 weeks old).MethodsThe study consisted of three experiments. The first determined the pharmacokinetics of articaine following intravenous administration of articaine hydrochloride (8 mg kg^–1). The second experiment investigated the anaesthetic efficacy and pharmacokinetics following cornual nerve block using 1.5% articaine hydrochloride. Anaesthesia of horn buds was evaluated using the response to pinprick test. Non-compartmental analysis was used. The final experiment determined the convulsive dose of articaine and its corresponding plasma concentration following intravenous infusion of articaine hydrochloride (4 mg kg^–1 minute^–1). Data are shown as mean ± standard deviation.ResultsThe mean terminal half-life (t_1/2λz), mean volume of distribution at steady state (Vd_ss) and mean plasma clearance (CL) of articaine following intravenous administration were 0.66 hour, 3.81 L kg^–1 and 5.33 L hour^–1 kg^–1, respectively. After cornual nerve block, the mean maximum plasma concentration of articaine was 587 ng mL^–1 at 0.22 hour and its mean t_1/2λz was 1.26 hours. Anaesthesia of horn buds was observed within 4 minutes following cornual nerve block. The mean dose required to produce convulsions was 16.24 mg kg^–1 and mean convulsive plasma concentrations of articaine and articainic acid were 9905 and 1517 ng mL^–1, respectively.ConclusionsIntravenous administration of 8 mg kg^–1 of articaine hydrochloride did not cause any adverse effects. Pharmacokinetic data suggest that articaine was rapidly eliminated and cleared. Cornual nerve block using 1.5% articaine hydrochloride alleviated the response to the acute nociceptive stimulus during disbudding.Clinical relevanceArticaine hydrochloride appears to be a safe and effective local anaesthetic for disbudding in goat kids.  相似文献   

Protein-lipid interactions in zein films investigated by surface plasmon resonance   总被引：2，自引：0，他引：2  

Wang Q  Crofts AR  Padua GW 《Journal of agricultural and food chemistry》2003,51(25):7439-7444

Experiments on the adsorption of alpha-zein (characterized by SDS-PAGE) from aqueous ethanol and 2-propanol solutions onto hydrophilic and hydrophobic surfaces are reported. Zein adsorption onto self-assembled monolayers (SAMs) was detected by surface plasmon resonance (SPR). Gold substrates were prepared by thermal evaporation on glass slides. Gold-coated surfaces were modified by depositing SAMs of either a long-chain carboxylic acid terminated thiol [COOH(CH2)(10)SH] or a methyl-terminated alkanethiol [CH3(CH2)(7)SH]. Experimental measurements indicated that zein interacted with both hydrophilic and hydrophobic surfaces. Zein concentration affected the thickness of bound zein layers. The estimated thickness of the zein monolayer deposited on hydrophilic surfaces was 4.7 nm. Zein monolayer thickness on hydrophobic surfaces was estimated at 4.6 nm. The topography of zein layers was examined by atomic force microscopy (AFM) after solvent was evaporated. Surface features of zein deposits depended on the adsorbing surface. On hydrophilic surfaces, roughness values were high and distinct ring-shaped structures were observed. On hydrophobic surfaces, zein formed a uniform and featureless coverage.  相似文献   

Effect of early age woody and herbaceous competition control on wood properties of loblolly pine     

Finto Antony  Laurence R. SchimleckLewis Jordan  Alexander ClarkRichard F. Daniels 《Forest Ecology and Management》2011,262(8):1639-1647

Early age competition control has been reported to significantly improve the growth and yield of plantation grown loblolly pine. The objective of this paper is to understand the changes in wood properties: basal area weighted whole disk SG, earlywood SG (EWSG), latewood SG (LWSG) and latewood percent (LWP) of 14 year-old trees which received early age herbaceous and hardwood competition control, using data collected from 13-sites across 4-physiographic regions in the southeastern USA. The study was laid out in a randomized complete block design and had four levels of weed control (no weed control; woody vegetation control; herbaceous vegetation control; and woody and herbaceous vegetation control), with four blocks at each site. Increment cores 12 mm in diameter were collected at breast height (1.37 m) from 9-trees in each plot and ring-by-ring SG, EWSG, LWSG and LWP measured using a X-ray densitometer. Whole disk basal area weighted SG and LWP were determined for each tree and used for analysis. A reduction in whole disk SG of 0.039 and 0.0014 and LWP of 7.38% and 3.62% was observed for trees which received total weed control compared to no weed control, for lower and upper Coastal Plain sites, respectively. For trees receiving total weed control compared to no weed control, it was observed that the diameter of the juvenile core increased by 20% on average across all physiographic regions. However, no change in the length of the juvenile period was observed among treatments other than the regional differences.  相似文献   

The kinesin Klp2 mediates polarization of interphase microtubules in fission yeast     

Carazo-Salas RE  Antony C  Nurse P 《Science (New York, N.Y.)》2005,309(5732):297-300

Fission yeast (Schizosaccharomyces pombe) cells grow longitudinally in a manner dependent on a polarized distribution of their interphase microtubules. We found that this distribution required sliding of microtubules toward the cell center along preexisting microtubules. This sliding was mediated by the minus end-directed kinesin motor Klp2, which helped microtubules to become properly organized with plus ends predominantly oriented toward the cell ends and minus ends toward the cell center. Thus, interphase microtubules in the fission yeast require motor activities for their proper organization.  相似文献   

Controlled elimination of clathrin heavy-chain expression in DT40 lymphocytes     

Wettey FR  Hawkins SF  Stewart A  Luzio JP  Howard JC  Jackson AP 《Science (New York, N.Y.)》2002,297(5586):1521-1525

We exploited the high rate of homologous recombination shown by the chicken B cell line DT40 to inactivate the endogenous alleles for clathrin heavy chain and replace them with human clathrin complementary DNA under the control of a tetracycline-regulatable promoter. Clathrin repression perturbed the activities of Akt-mediated and mitogen-activated protein kinase-mediated signaling pathways and induced apoptosis; this finding suggests that in DT40 cells clathrin helps to maintain the integrity of antiapoptotic survival pathways. We also describe a variant cell line in which these signaling pathways were unaffected by clathrin down-regulation. This variant cell line did not undergo apoptosis in the absence of clathrin and was used to examine the effects of clathrin depletion on membrane-trafficking pathways. Receptor-mediated and fluid-phase endocytosis were both substantially inhibited, and transferrin-receptor recycling was modestly inhibited. Surprisingly, clathrin removal did not affect the morphology or biochemical composition of lysosomes.  相似文献   

Direct measurements of the convective recycling of the upper troposphere     

Bertram TH  Perring AE  Wooldridge PJ  Crounse JD  Kwan AJ  Wennberg PO  Scheuer E  Dibb J  Avery M  Sachse G  Vay SA  Crawford JH  McNaughton CS  Clarke A  Pickering KE  Fuelberg H  Huey G  Blake DR  Singh HB  Hall SR  Shetter RE  Fried A  Heikes BG  Cohen RC 《Science (New York, N.Y.)》2007,315(5813):816-820

We present a statistical representation of the aggregate effects of deep convection on the chemistry and dynamics of the upper troposphere (UT) based on direct aircraft observations of the chemical composition of the UT over the eastern United States and Canada during summer. These measurements provide unique observational constraints on the chemistry occurring downwind of convection and the rate at which air in the UT is recycled. These results provide quantitative measures that can be used to evaluate global climate and chemistry models.  相似文献   

Effect of choline chloride premedication on xylazine-induced hypoxaemia in sheep     

Preet M. Singh  Katherine Reid  Ravindra Gaddam  Madhav Bhatia  Stefan Smith  Antony Jacob  Paul Chambers 《Veterinary anaesthesia and analgesia》2017,44(5):1149-1155

Objective

To determine the anti-inflammatory efficacy of choline in vivo and in vitro and to investigate the anti-inflammatory mechanisms of choline.

Study design

Randomized, controlled studies.

Animals

In vivo trials used 16 Romney sheep. In vitro experiments utilized RAW 264.7 mouse macrophage cells.

Methods

Hypoxaemia induced in 16 sheep by intravenous (IV) injection of 50 μg kg^–1 xylazine, an α-2 agonist, was measured in sheep at 0, 1 and 4 minutes using arterial blood gas analysis with and without 50 mg kg^–1 IV choline chloride premedication. Cell culture studies used enzyme-linked immunosorbent assay to measure the release of tumour necrosis factor (TNF-α) from lipopolysaccharide (LPS) stimulated macrophages with and without choline chloride premedication. TNF-α release was compared to thalidomide suppressed and untreated cells.

Results

Choline premedication in sheep mitigated a reduction in arterial partial pressure of oxygen (PaO₂) but did not prevent development of clinically significant hypoxaemia. Decrease in mean PaO₂ of choline treated sheep was 6.36 kPa (47.7 mmHg) compared to 9.81 kPa (73.6 mmHg) in control sheep. In vitro studies demonstrate that choline administered concurrent with LPS activation did not significantly suppress TNF-α expression but that treatment of cells with choline 10 minutes prior to LPS activation did significantly suppress TNF-α expression. Choline pretreated cells expressed 23.99 ± 4.52 ng mg^–1 TNF-α while LPS only control cells expressed 33.83 ± 3.20 ng mg^–1.

Conclusions

Choline is able to prevent macrophage activation in vitro when administered prior to LPS activation and may reduce hypoxaemia in sheep developing pulmonary oedema after xylazine administration. This effect requires premedication with choline.

Clinical relevance

Pharmacological manipulation of autonomic inflammatory responses holds promise for the treatment of inflammation. However, the complex cellular mechanisms involved in this reflex means that an adequate therapy should approach multiple pathways and mechanisms of the inflammatory response.  相似文献   

Preliminary investigations into the interactions of herbicides with aqueous humic substances     

Rüdiger Kuckuk  Wieland Hill  Jürgen Nolte  Antony N. Davies 《Pest management science》1997,51(4):450-454

The binding of the herbicides to aqueous humic substances was investigated using the herbicide mecoprop and a reference humic substance ‘Hohlohsee’. Initial results from 2D fluorescence spectrometry, infra-red spectroscopy and Curie-point pyrolysis gas chromatography/infra-red spectroscopy tentatively characterise the nature of the interaction. ©1997 SCI  相似文献