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排序方式: 共有1074条查询结果,搜索用时 734 毫秒
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Sugerman BE Ercolano B Barlow MJ Tielens AG Clayton GC Zijlstra AA Meixner M Speck A Gledhill TM Panagia N Cohen M Gordon KD Meyer M Fabbri J Bowey JE Welch DL Regan MW Kennicutt RC 《Science (New York, N.Y.)》2006,313(5784):196-200
We present late-time optical and mid-infrared observations of the Type II supernova 2003gd in the galaxy NGC 628. Mid-infrared excesses consistent with cooling dust in the ejecta are observed 499 to 678 days after outburst and are accompanied by increasing optical extinction and growing asymmetries in the emission-line profiles. Radiative-transfer models show that up to 0.02 solar masses of dust has formed within the ejecta, beginning as early as 250 days after outburst. These observations show that dust formation in supernova ejecta can be efficient and that massive-star supernovae could have been major dust producers throughout the history of the universe. 相似文献
94.
The principal molecular determinant of virulence of Newcastle disease virus (NDV) is the amino acid sequence at the fusion cleavage activation site. To extend the understanding of the role of the fusion cleavage activation site in NDV virulence, the pathogenesis in chickens of a lentogenic LaSota isolate and two infectious clones, NDFL and NDFLtag, were compared. NDFL is an infectious clone of a lentogenic NDV strain (LaSota E13-1), and NDFLtag is the infectious clone with the fusion cleavage site sequence mutated to the virulent motif. NDFL and NDFLtag were described by Peeters et al. The viruses were inoculated intraconjunctivally into groups of 4-wk-old white leghorn chickens and compared in a pathogenesis study for determination of disease causation (clinical signs of disease, gross lesions, histology, virus isolation, and serology) and viral distribution (presence of viral nucleoprotein and mRNA was detected by immunohistochemistry and in situ hybridization, respectively). The modification of the fusion cleavage activation site to the virulent motif in the infectious clone only slightly increased disease severity and viral distribution in the pathogenesis assessment, even though dramatically increased pathogenicity of NDFLtag was confirmed by standard pathogenicity index tests. The result, that the mutated fusion cleavage site of NDV-NDFLtag had only a small influence on pathogenesis in chickens compared to either E13-1 or NDFL, suggests that the pathogenic effects of NDV are not dependent on the fusion cleavage site alone. 相似文献
95.
Effect of industrial dehydration on the soluble carbohydrates and dietary fiber fractions in legumes
Martín-Cabrejas MA Aguilera Y Benítez V Molla E López-Andréu FJ Esteban RM 《Journal of agricultural and food chemistry》2006,54(20):7652-7657
The effects of soaking, cooking, and industrial dehydration treatments on soluble carbohydrates, including raffinose family oligosaccharides (RFOs), and also on total dietary fiber (TDF), insoluble dietary fiber (IDF), and soluble (SDF) dietary fiber fractions were studied in legumes (lentil and chickpea). Ciceritol and stachyose were the main alpha-galactosides for chickpea and lentil, respectively. The processing involved a drastic reduction of soluble carbohydrates of these legumes, 85% in the case of lentil and 57% in the case of chickpea. The processed legume flours presented low residual levels of alpha-galactosides, which are advisable for people with digestive problems. Processing of legumes involved changes in dietary fiber fractions. A general increase of IDF (27-36%) due to the increase of glucose and Klason lignin was observed. However, a different behavior of SDF was exhibited during thermal dehydration, this fraction increasing in the case of chickpea (32%) and decreasing in the case of lentil (27%). This is probably caused by the different structures and compositions of the cell wall networks of the legumes. 相似文献
96.
Gómez-Villamandos RJ Palacios C Benítez A Granados MM Domínguez JM López I Ruiz I Aguilera E Santisteban JM 《Journal of veterinary pharmacology and therapeutics》2006,29(3):157-163
The objective of this study was to evaluate dexmedetomidine as a premedicant in dogs prior to propofol-desflurane anaesthesia, and to compare it with medetomidine. Six healthy dogs were anaesthetized. Each dog received intravenously (i.v.) five preanaesthetic protocols: D1 (dexmedetomidine, 1 microg/kg, i.v.), D2 (dexmedetomidine, 2 microg/kg, i.v.), M1 (medetomidine, 1 microg/kg, i.v.), M2 (medetomidine, 2 microg/kg, i.v.), or M4 (medetomidine, 4 microg/kg, i.v.). Anaesthesia was induced with propofol (2.3-3.3 mg/kg) and maintained with desflurane. The following variables were studied: heart rate (HR), mean arterial pressure, systolic arterial pressure, diastolic arterial pressure, respiratory rate (RR), arterial oxygen saturation, end-tidal CO2, end-tidal concentration of desflurane (EtDES) required for maintenance of anaesthesia and tidal volume. Arterial blood pH (pHa) and arterial blood gas tensions (PaO2, PaCO2) were measured during anaesthesia. Time to extubation, time to sternal recumbency and time to standing were also recorded. HR and RR decreased significantly during sedation in all protocols. Cardiorespiratory variables during anaesthesia were statistically similar for all protocols. EtDES was significantly different between D1 (8.1%) and D2 (7.5%), and between all doses of medetomidine. Desflurane requirements were similar for D1 and M2, and for D2 and M4 protocols. No statistical differences were observed in recovery times. The combination of dexmedetomidine, propofol and desflurane appears to be effective for induction and maintenance of general anaesthesia in healthy dogs. 相似文献
97.
Zuckerman B 《Science (New York, N.Y.)》2006,313(5795):1885-1886
98.
Sjöblom T Jones S Wood LD Parsons DW Lin J Barber TD Mandelker D Leary RJ Ptak J Silliman N Szabo S Buckhaults P Farrell C Meeh P Markowitz SD Willis J Dawson D Willson JK Gazdar AF Hartigan J Wu L Liu C Parmigiani G Park BH Bachman KE Papadopoulos N Vogelstein B Kinzler KW Velculescu VE 《Science (New York, N.Y.)》2006,314(5797):268-274
99.
L. Tsror O. Erlich M. Hazanovsky B. Ben Daniel U. Zig S. Lebiush 《Plant pathology》2012,61(1):161-168
Over a 5‐year period (2006–2010), 277 certified, visually healthy potato seed lots, imported from Europe to Israel for commercial use, were tested for Dickeya spp. latent infection by PCR analysis (277 seed lots) and ELISA (154 seed lots). Seeds from these lots were grown in commercial potato fields which were inspected twice a season by Plant Protection and Inspection Services (PPIS). Stem samples were tested for the presence of Dickeya spp. by PCR analysis. PCR and ELISA results from seed lot testing correlated with disease expression in 74 and 83·8% of the cases, respectively. Positive laboratory results with no disease symptoms in the field (‘+lab/?field’ results) comprised 24·7 and 9·7% of the PCR and ELISA analyses, respectively, whereas negative laboratory results with disease symptoms in the field results (‘?lab/+field’) were obtained in 1·3 and 6·5%, of cases respectively. Maximum disease incidence, as well as the number of cultivars expressing disease symptoms, increased over the years of this study, indicating an increase in the prevalence of the disease. Severe disease incidence was observed on cvs Dita, Rodeo, Desiree, Mondial, Tomensa and Jelly. Of the 55 imported seed lots from which disease was recorded in the field, 49 originated from the Netherlands, four from Germany and two from France. None originated from Scotland. 相似文献
100.
Z. Mendel A. Protasov M. Sharon A. Zveibil S. Ben Yehuda K. O’Donnell R. Rabaglia M. Wysoki S. Freeman 《Phytoparasitica》2012,40(3):235-238
The ambrosia beetle, Euwallacea fornicatus Eichhoff, was first recorded in Israel in 2009. The symbiotic fungus Fusarium sp., carried in mycacangia located in the anterior region of the female head, is responsible for the typical wilt symptoms inflicted on avocado (Persea americana Miller) trees. The beetle?Cfungus complex has become a serious threat to the future of the avocado industry in Israel. 相似文献