961 resultados para 6-55


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目的:建立反相高效液相色谱法同时测定四川及青海地区部分獐牙菜中獐牙菜苦苷、龙胆苦苷、芒果苷、当药醇苷、异荭草苷、1,8-二羟基-3-甲氧基(口山)酮的含量.方法:采用RP-HPLC,使用Kromasil C_(18)(4.6 mm×250mm,5 μm)柱;流动相甲醇-水(含0.02%磷酸);梯度洗脱程序为0~50 min,甲醇的体积分数(下同)由20%上升至80%;50~55 min由80%增至100%,55~60 min为100%,流速1 mL•min~(-1),检测波长254 nm;柱温35 ℃.结果:6种成分均达到基线分离,线性良好.结论:该方法快速、准确、重复性好,为该类药材的入药提供了理论依据.

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报道了点地梅属6种12个居群的染色体数目和核型。它们的染色体数目(2n)、核型公式(KF)、染色体相对长度组成(CRL)、核型不对称性系数(A. sK%)和核型类型(KT)分别为:点地梅在南京的2个居群都是2n=2x=20,KF=18m+2sm, CRL=2L+6M_2+10M_1+2S,核型KT属于1A型,但核型不对称性系数As. K%分别是55.04%和56.71%;北点地梅在内蒙古锡林郭勒和白音锡勒居群的2n=2x=20,KF分别为16m+2sm+2st+1b和16m+2sm+2st+4b,染色体相对长度组成分别是14M_2+4M_1+2S+1b和12M_2+6M_1+2S+4b,核型不对称性系数As. K%分别是57.65%和58.86%,属2A型和2B型;高原点地梅在青海玛沁县昌马河居群和兴海县温泉居群都是2n=2x=20,KF=10m+8sm+2st。但相对长度组成分别为12M_2+8M_1和4L+6M_2+6M_1+4S, As. K%分别是60.35%和62.57%,属2A型和2B型;雅江点地梅在青海玛多县巴颜喀拉山居群和大通县达坡山居群分别为2n=4x=40和20n=6x=60,KF=36m+2sm+2st和KF=46m+10sm+4st+2b, CRL=2l+20M_2+14M_1+4S和GRL=6L+30M_2+16M_1+8S+2b, As.K%分别为55.62%和58.31%,核型均属于2B;巴颜喀拉山北坡的鳞叶点地梅2n=40、60、80。西藏点地梅青湖居群中有2种细胞型:①2n=2x=24, KF=12m+6sm+6st+4b, CRL=6L+2M_2+8M_1+4S+4b, As. K%=65.74%,核型属2B;②2n=2x=22,KF=14m+4sm(2SAT)+4st, CRL=4L+6M_2+8M_1(2SAT)+4S,As. K%=63.40%,核型也属于2B。西宁西山湾居群也有2种细胞型;①2n=3x=36, KF=36m,CRL=4L+12M_2+20M_1, As. K%=54.82%,核型属1A;②2n=3x=33,KF=33m, CRL=3L+12M_2+18M_1,As. K%=52.11%,核型属1A。点地梅属的染色体原始基数可能是x=10,在种间或种内观察到有3种核型变化:染色体非整倍性变化、多倍化和核型不对称性变化。将2倍体居群的核型和不对称性进行比较,可以看出点地梅是较对称的核型。因此,在研究的种中应是比较原始的类群。北点地梅的核型不对称性和进化程度高于点地梅而低于高原点地梅和西藏点地梅。染色体多倍化的雅江点地梅、鳞叶点地梅和西藏点地梅等在核型上也许是最进化的类群。

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Ultraviolet(UV) radiation at four wavelengths (305, 320, 340 and 380 nm) and photosynthetically active radiation (PAR) were measured from May 1994 to October 1999 using Biospherical UV radiometers. A surface reference sensor located on the roof of the Marine Station at Helgoland recorded values every 5 min, and an equivalent profiling underwater sensor was used for measurements in the sea at approximately monthly intervals. The ratio of 305-nm radiation to PAR varied seasonally, with a 14-fold increase from winter to summer. A much weaker seasonal trend (ca. 1.5-fold) was apparent in the ratio of 320-nm radiation to PAR, but there was no seasonal trend in the ratios of 340- or 380-nm radiation to PAR. The year-to-year variations in 305-nm radiation were also much greater relative to PAR than for the other UV wavelengths, but there was no evidence of a change in the 305 nm:PAR ratio over the study period. The ratios of both 305- and 320-nm radiation to PAR increased from dawn to midday, but those of 340- and 380-nm radiation were almost constant through the day, except shortly before sunrise and after sunset when the proportions of 340- and 380-nm radiation increased. Underwater measurements of PAR and UV suggest that the 1% depth for 305-nm radiation was little more than 1 m, but this estimate is valid only for summer and autumn because, in other seasons, few reliable readings for 305-nm radiation could be obtained underwater, and no attenuation coefficient could be calculated. The 1% depths recorded for the other UV wavelengths in the middle 6 months of the year were 2.0 m for 320 nm, 2.6 m for 340 nm and 4.6 m for 380 nm, compared with 12 m for PAR, but the attenuation of all wavebands increased sharply in October and remained higher until March. An analysis of the influence of sun angle, total column ozone concentration, the proportion of skylight, and cloud cover on the ratio of UV wavelengths to PAR in surface irradiance demonstrated that solar angle has a greater influence than ozone concentration on the irradiance at 305 nm, and that the typical occurrence of ozone

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Several studies have assessed changes in frequency of -174 interleukin (IL)-6 single nucleotide polymorphism (SNP) with age. If IL-6 tracks with disability and age-related diseases, then there should be reduction, in the oldest old, of the frequency of homozgyous GG subjects, who produce higher IL-6 levels. However, discordant results have been obtained. To explore the relationship between this polymorphism and longevity, we analyzed individual data on long-living subjects and controls from eight case-control studies conducted in Europeans, using meta-analysis. There was no significant difference in the IL-6 genotype between the oldest old and controls (Odds Ratio [OR]=0.96; 95% C.I.: 0.77-1.20; p=0.71), but there was significant between-study heterogeneity (I(2)=55.5%). In a subgroup analyses when male centenarians from the three Italian studies were included, the frequency of the IL-6 -174 GG genotype was significantly lower than the other genotypes (OR=0.49; 95% C.I.: 0.31-0.80; p=0.004), with no evidence of heterogeneity (I(2)=0%). Our data supports a negative association between the GG genotype of IL-6 SNP and longevity in Italian centenarians, with males who carry the genotype being two times less likely to reach extreme old age compared with subjects carrying CC or CG genotypes. These findings were not replicated in other European groups suggesting a possible interaction between genetics, sex and environment in reaching longevity.

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The delivery of spatially modulated radiation fields has been shown to impact on in vitro cell survival responses. To study the effect of modulated fields on cell survival, dose response curves were determined for human DU-145 prostate, T98G glioma tumour cells and normal primary AGO-1552 fibroblast cells exposed to modulated and non-modulated field configurations delivered using a 6 MV Linac with multi-leaf collimator. When exposed to uniform fields delivered as a non-modulated or modulated configuration, no significant differences in survival were observed with the exception of DU-145 cells at a dose of 8 Gy (p = 0.024). Survival responses were determined for exposure to non-uniform-modulated beams in DU-145 and T98G and showed no deviation from the survival response observed following uniform non-modulated exposures. The results of these experiments indicate no major deviation in response to modulated fields compared to uniform exposures.

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Inorganic polyphosphate (polyP) is increasingly being recognized as an important phosphorus sink within the environment, playing a central role in phosphorus exchange and phosphogenesis. Yet despite the significant advances made in polyP research there is a lack of rapid and efficient analytical approaches for the quantification of polyP accumulation in microbial cultures and environmental samples. A major drawback is the need to extract polyP from cells prior to analysis. Due to extraction inefficiencies this can lead to an underestimation of both intracellular polyP levels and its environmental pool size: we observed 23-58% loss of polyP using standard solutions and current protocols. Here we report a direct fluorescence based DAPI assay system which removes the requirement for prior polyP extraction before quantification. This increased the efficiency of polyP detection by 28-55% in microbial cultures suggesting quantitative measurement of the intracellular polyP pool. It provides a direct polyP assay which combines quantification capability with technical simplicity. This is an important step forward in our ability to explore the role of polyP in cellular biology and biogeochemical nutrient cycling.

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Several studies have assessed changes in frequency of -174 interleukin (IL)-6 single nucleotide polymorphism (SNP) with age. If IL-6 tracks with disability and age-related diseases, then there should be reduction, in the oldest old, of the frequency of homozygous GG subjects, who produce higher IL-6 levels. However, discordant results have been obtained. To explore the relationship between this polymorphism and longevity, we analyzed individual data on long-living subjects and controls from eight case-control studies conducted in Europeans, using meta-analysis. There was no significant difference in the IL-6 genotype between the oldest old and controls (Odds Ratio [OR]=0.96; 95% C.I.: 0.77-1.20; p=0.71), but there was significant between-study heterogeneity (I2=55.5%). In a subgroup analyses when male centenarians from the three Italian studies were included, the frequency of the IL-6 -174 GG genotype was significantly lower than the other genotypes (OR=0.49; 95% C.I.: 0.31-0.80; p=0.004), with no evidence of heterogeneity (I2=0%). Our data supports a negative association between the GG genotype of IL-6 SNP and longevity in Italian centenarians, with males who carry the genotype being two times less likely to reach extreme old age compared with subjects carrying CC or CG genotypes. These findings were not replicated in other European groups suggesting a possible interaction between genetics, sex and environment in reaching longevity.

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In North America, terrestrial records of biodiversity and climate change that span Marine Oxygen Isotope Stage (MIS) 5 are rare. Where found, they provide insight into how the coupling of the ocean-atmosphere system is manifested in biotic and environmental records and how the biosphere responds to climate change. In 2010-2011, construction at Ziegler Reservoir near Snowmass Village, Colorado (USA) revealed a nearly continuous, lacustrine/wetland sedimentary sequence that preserved evidence of past plant communities between similar to 140 and 55 lea, including all of MIS 5. At an elevation of 2705 m, the Ziegler Reservoir fossil site also contained thousands of well-preserved bones of late Pleistocene megafauna, including mastodons, mammoths, ground sloths, horses, camels, deer, bison, black bear, coyotes, and bighorn sheep. In addition, the site contained more than 26,000 bones from at least 30 species of small animals including salamanders, otters, muskrats, minks, rabbits, beavers, frogs, lizards, snakes, fish, and birds. The combination of macro- and micro-vertebrates, invertebrates, terrestrial and aquatic plant macrofossils, a detailed pollen record, and a robust, directly dated stratigraphic framework shows that high-elevation ecosystems in the Rocky Mountains of Colorado are climatically sensitive and varied dramatically throughout MIS 5 

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Cartel, en italien, de Cagnino di Gonzaga à Cesare Fregoso. Bozolo,31 juillet 1539 (fol. 112), orig. imprimé, avec le sceau de Gonzaga. — Extraits des Mémoires de Sully (fol. 14). — Duels de Jean de Harcourt et Guillaume III de Tancarville, 1286 (fol. 20), — Raymond du Marcadil de Penne en Agenois et Étienne Donnadieu, 1330 (fol. 24), — M. de Sauvebeuf et Peyrot de Rastinhac, 1587 (fol. 26), — baron de Conros et Carbonat (fol. 29), — Louis de Loudierche, de Grizol et de Cheyladet, 1612 (fol 31, 59), — MM. de Candale et de Schomberg (fol. 36), — combat de la Barrière, 1605 (fol. 37). — Édit de Henri IV défendant les duels (fol. 39). — Accords faits par le connétable, les maréchaux de France et les lieutenants généraux des provinces entre MM. de Clermont et de S. Gery d'Avignon (fol. 50), — de Reilhac et de Drageac (fol. 53), — le duc de Nevers et M. de Montpensier, 1580 (fol. 55), — de Brezolles et de Carluz de Calvimond, 1610 (fol. 57), — de Naves et de Montaignac, 1613 (fol. 61), — le comte de Sault et M. de Brissac, 1638 (fol. 62). — Extraits du « stylus antiquus Parlamenti Parisiensis Caroli Molinoei », éd. 1558 (fol. 66, 72, 74, 156), — du « Coustumier de Normendie », éd. 1539 (fol. 76). — Duels de Jacques Le Gris et Jean de Carouges, 1387 (fol. 84) et autres duels extraits de Froissart (fol. 99 et suiv.). — Lettre orig. de Gaucher de Dinteville à Mgr le Dauphin [Henri II], Venise, 20 décembre 1538 (fol. 142). — « Les Cartelz, reponces et procès-verbaux du different d'entre le sieur de Vassé et le comte Guillaume de Furstenberg, 1540 (fol. 144).

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The thermal properties of short Nylon-6 fiber-reinforced Styrene butadiene rubber (SBR) composites were studied by Thermogravimetric Analysis (TGA). The effect of epoxy-based bonding agent on thermal degradation of the gum and the composites was also studied. The thermal stability of the SBR was enhanced in the presence of Nylon-6 fibers and the stability of the composites increased in the presence of bonding agent. The epoxy resin did not significantly change the thermal stability of SBR gum vulcanizate. Results of kinetic studies showed that the degradation of SBR and the short nylon fiber-reinforced composites with and without bonding agents followed first-order kinetics.

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Estudio realizado por el grupo de investigación 'Educació i ciutadania' del Departament de Pedagogia Aplicada i Psicologia de l'Educació de la UIB, en el marco del proyecto XarxaSeguraIB. Resumen tomado de la publicación. Incluye tablas y gráficos de datos con los resultados obtenidos. Incluye un ejemplar en blanco del cuestionario realizado

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Resumen tomado de la publicación. Resumen en castellano e inglés