Therapeutic Erythrocytapheresis Is Effective in Treating High Altitude Polycythemia on the Qinghai-Tibet Plateau     

《The Forestry Chronicle》2020,31(4):426-430

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基于多时相双极化SAR数据的作物种植面积提取   总被引：2，自引：0，他引：2  

Gulnur ISAK  Mamat SAWUT  MA Chun-Yue 《作物学报》2020,46(7):1099-1111

及时准确地获取农作物的空间分布信息和种植面积,在农业生产管理与农业政策的制定等斱面具有非常重要的作用。本文以多时相Sentinel-1A影像(4月17日、5月5日、6月16日、7月22日、8月27日、9月2日)为主要数据源,根据研究区作物的物候特征,提取棉花、玉米和果树在不同生长期的后向散射系数(Sigma)和归一化后向散射系数(Gamma)。通过对作物不同极化、不同时相后向散射系数的统计,建立散射特征时序变化曲线,幵分析其特征。利用人工神经网络(Artificial neural network)、支持向量机(Support vector machine)和随机森林(Random forest) 3种分类斱法对研究区的主要农作物迚行分类识别以及种植面积提取,幵对分类结果对比分析和验证。结果表明, 1)棉花的后向散射系数在6月现蕾期和7月开花期明显上升,8月仹达最高值,变化特征最明显,易与其他作物区分;玉米和果树的后向散射系数在9月仹与其他地物之间表现出显著差异。2)相较于神经网络和支持向量机,随机森林的分类效果最好,总体精度达88.97%。其中,对棉花和果园的分类精度为90.88%和93.17%,对玉米的分类效果最差,仅有71.6%。综上所述,多时相双极化SAR数据在不同类型作物的识别及面积提取斱面具有一定的应用潜力。  相似文献   

基于茶籽壳代替木屑栽培茶树菇配方筛选试验     

魏云辉  李菁  胡中娥  王洪秀  熊小文 《中国食用菌》2014,(5):30-32

不同比例的茶籽壳和木屑组合成5个试验配方,比较不同配方对菌丝生长、子实体经济性状和生物转化率的影响。试验结果表明,在供试的5个配方中,配方4（棉籽壳50%、茶籽壳15%、木屑5%、麦麸20%、玉米粉7%、石膏1%、磷肥1%、石灰1%）为优选配方。  相似文献   

基于UPLC-QTOF/MS的小麦发芽代谢组学分析方法   总被引：1，自引：0，他引：1  

Li-Na WANG  Bu-Jun WANG 《作物学报》2019,45(12):1899-1904

为探究不同提取方法对发芽小麦代谢物提取效果的影响,本研究建立了基于超高效液相色谱-四级杆飞行时间质谱(UPLC-QTOF/MS)的发芽小麦非靶向代谢组学样品前处理方法和分析方法,以发芽2 d周麦26籽粒为材料,设计提取溶剂、提取方式、提取时间3个因素在3个水平上L9(34)正交试验,并通过主成分分析和聚类分析确定提取效果最佳的组合。以80%乙腈(0.1%甲酸)震摇提取30 min可检测出1609个代谢峰,说明提取溶剂对代谢物提取效果起主要作用。共鉴定出92种小麦代谢物。  相似文献   

我国蔬菜肥料利用率现状与提高对策   总被引：4，自引：0，他引：4  

黄梓翀  刘善江  孙昊  侯立柱  吴荣  薛文涛 《蔬菜》2021,(7):43-50

我国露地蔬菜种植和设施蔬菜种植养分用量均超过蔬菜生长所需,导致土壤次生盐渍化、肥料利用率低,增加了面源污染风险,在分析这些现状的基础上,对造成蔬菜种植中氮、磷、钾肥料利用率低下的原因进行了分析,如有机肥与化肥施用配比随意性强,搭配不合理;氮、磷、钾肥配施比例不合理;大量元素与中微量元素配合施用不合理;肥料总施用量过大;土壤自身的原因等。并提出了提高肥料利用率的测土与科学配方施肥、有机肥与无机肥合理配合施用、采用水肥一体化技术和土壤调理剂等措施,有望提高我国蔬菜肥料利用率,节约资源,防止面源污染,实现蔬菜生产的可持续绿色发展。  相似文献   

适用于转录组测序的大白菜小孢子总RNA提取方法筛选     

林燕  李菲  张淑江  张慧  章时藩  孙日飞  张振贤 《中国蔬菜》2014,1(11):15

为了找到适用于转录组测序要求的大白菜小孢子总RNA 提取方法，以出胚率较高的吉红82 为试材，以热激诱导处理后的小孢子为研究对象，比较分析了TRIzol 法、改良CTAB 法及超纯试剂盒法3 种方法的RNA 提取效果。结果表明：TRIzol法（磨样）和改良CTAB 法提取的RNA 浓度较高，但完整性较差；超纯RNA 提取试剂盒法提取的RNA 质量最高，且完整性好，能够满足转录组测序的要求。  相似文献   

Detection of cigarettes and other tobacco products by giant African pouched rats (Cricetomys gambianus)     

《Journal of Veterinary Behavior: Clinical Applications and Research》2014,9(5):262-268

If the illicit tobacco trade were eliminated, governments could gain at least $31.3 billion a year, and more than 164,000 premature deaths a year could be avoided after 2030 (Joossens, Merriman, Ross, and Raw, 2009). Dogs have been used successfully in tobacco control programs, and there is a good chance that rats could also play an important role. In the present experiment, giant African pouched rats were trained to respond to filters that had been stored together with cigarettes (i.e., soaked) and to not respond to filters that had been soaked with noncigarette items. Generalization to untrained types of tobacco was then tested. The sensitivity of 4 rats trained on filters soaked with 1 of 7 types of cigarettes ranged from 86% to 100% (mean, 95%). There was very little evidence of generalization when the rats were tested on tobacco leaves and snuff but good evidence of generalization when the rats were tested on cigarettes that had been soaked with strong-smelling additives. These findings suggest that rats may be a valuable asset in the global effort to control illicit cigarette trade.  相似文献   

Relevance of Osmotic and Frost Protecting Compounds for the Winter Hardiness of Autumn Sown Sugar Beet          下载免费PDF全文

J. Loel  C. M. Hoffmann 《Journal of Agronomy and Crop Science》2015,201(4):301-311

The cultivation of autumn sown sugar beet (winter beet) is supposed to result in a marked yield increase compared with spring sown sugar beet. Although the importance of the growth stage reached before winter for the survival of autumn sown sugar beet has already been shown, it is not clear to which extent osmotic and potentially frost protecting compounds may contribute to winter hardiness. The study thus aimed to analyse the acclimatization process of sugar beet to low temperatures and to identify compounds which are important for survival of frost. Field trials with autumn sown sugar beet were conducted at eleven environments in Germany from 2009/10 to 2012/13, which were accompanied by greenhouse experiments with controlled temperature regimes. In the field trials, the survival rates after winter varied from 0 % to 99 %, but only in four environments differences between the five genotypes occurred. During acclimatization, betaine, glutamine, proline and raffinose were markedly accumulated and osmolality was enhanced. In particular betaine, amino acids and osmolality showed a positive correlation to the survival rate and were thus identified as potentially frost protecting substances for sugar beet. In contrast, raffinose and proline seem to act rather as stress indicators as they were negatively related to survival. Possible frost protecting substances were identified which can be used in breeding to improve the winter hardiness of sugar beet.  相似文献   

高含固率木质纤维素厌氧发酵物总DNA的4种提取方法比较     

马旭光  刘素君  江滔  常佳丽  唐琼 《中国沼气》2020,(2):28-35

不同的样本特性和提取方法对获得微生物总DNA的质量有重要影响。文章基于高含固率木质纤维素厌氧发酵物腐殖酸、酚类物质含量高、质地均一性差、微生物浓度低的特点,研究了4种方法提取不同高含固率粪秸厌氧发酵物中微生物总DNA的效果。结果表明,常规的十二烷基磺酸钠法(sodium dodecyl sulfate,SDS)、十二烷基磺酸钠和溴化十六烷基三甲铵结合法(sodium dodecyl sulfate and cetyltrimethyl ammonium bromide,SDS-CTAB)和商业的粪便试剂盒法提取的DNA质量均较差,SDS法和试剂盒法未能获得聚合酶链式反应(polymerase chain reaction,PCR)扩增目的条带,SDS-CTAB法得到的条带较模糊;改进SDS-CTAB法获得的DNA杂质少、纯度高,具有较好的稳定性,A260/A280和A260/A230值分别为1.74~1.86和1.65~1.86,每克样品的DNA浓度在50 ng·μL^-1以上,电泳条带单一齐整、清晰明亮,PCR扩增的目的条带清晰度高,适宜后续分子生物学技术的分析。林格氏液洗脱、聚乙烯吡咯烷酮-40(Polyvinyl Pyrrolidone-40,PVP-40)洗涤液除杂以及裂解液和多种酶联合破壁是改进SDS-CTAB法获得该类专一性样本高质量微生物总DNA的关键步骤。  相似文献   

Pharmacokinetics of xylazine after 2-, 4-, and 6-hr durations of continuous rate infusions in horses     

Klaus Hopster  Lawrence R. Soma  Xiaoqing Li  Charlotte Hopster-Iversen  Raymond C. Boston  Bernd Driessen 《Journal of veterinary pharmacology and therapeutics》2020,43(6):557-564

Intravenous (i.v.) bolus administration of xylazine (XYL) (0.5 mg/kg) immediately followed by a continuous rate infusion (CRI) of 1 mg kg⁻¹ hr⁻¹ for 2, 4, and 6 hr produced immediate sedation, which lasted throughout the duration of the CRI. Heart rate decreased and blood pressure increased significantly (p > .05) in all horses during the first 15 min of infusion, both returned to and then remained at baseline during the duration of the infusion. Compartmental models were used to investigate the pharmacokinetics of XYL administration. Plasma concentration–time curves following bolus and CRI were best described by a one-compartment model. No differences were found between pharmacokinetic estimates of the CRIs for the fractional elimination rate constant (K_e), half-life (t_1/2e), volume of distribution (V_d), and clearance (Cl). Median and range were 0.42 (0.15–0.97)/hr, 1.68 (0.87–4.52) hr, 5.85 (2.10–19.34) L/kg, and 28.7 (19.6–39.5) ml min⁻¹ kg⁻¹, respectively. Significant differences were seen for area under the curve ( ) (p < .0002) and maximum concentration (C_max) (p < .04). This indicates that with increasing duration of infusion, XYL may not accumulate in a clinically relevant way and hence no adjustments are required in a longer XYL CRI to maintain a constant level of sedation and a rapid recovery.  相似文献