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排序方式: 共有343条查询结果,搜索用时 15 毫秒
331.
为探讨提高土壤中秸秆发酵效率的新途径,本试验采用盆栽方法研究了秸秆配施外源蛋白酶对土壤速效养分、有机质、pH值以及后季作物生长的影响。结果表明,整个种植期内,秸秆施酶处理土壤速效氮、磷、钾及有机质含量都高于不施酶处理,小麦收获时,施酶处理速效氮、磷、钾及有机质含量分别高出不施酶处理0.74-1.74mg/kg,0.53—1.33mg/kg,3.90—6.57mg/kg,0.07—0.13g/kg;盆栽小麦叶绿素含量、根系活力、株高和于物质含量都比不施酶处理有所提高,子粒产量比对照提高19.84%~34.11%。可见,秸秆配施外源蛋白酶可以提高土壤肥力并且促进后季作物毕长。 相似文献
332.
Zhou L Zhao M Ennahar S Bindler F Marchioni E 《Journal of agricultural and food chemistry》2012,60(1):293-298
In this study, molecular species of sphingomyelin (SM) in egg yolk, calf brain, ox liver, and krill oil were investigated. Classes of phospholipids (PLs) were purified, identified, and quantified by normal phase semipreparative high-performance liquid chromatography (HPLC) combined with evaporative light scattering detectors (ELSD). For SM molecular species identification, pure SM collected through a flow splitter was loaded to HPLC-electrospray ionization-tandem mass spectrometry (LC-ESI-MS(2)), with 100% methanol containing 5 mM ammonium formate as mobile phase. In addition to classes of PLs, the used approach allowed the determination of profiles of SM species in egg yolk, ox liver, and calf brain, whereas krill oil turned out not to contain any SM. It also allowed the separation and identification of SM subclasses, as well as tentative identification of species with the same molecular mass, including isomers. The results showed that egg yolk contained the highest proportion of (d18:1-16:0)SM (94.1%). The major SM molecular species in ox liver were (d18:1-16:0)SM (25.5%), (d18:1-23:0)SM (19.7%), (d18:1-24:0)SM (13.2%), and (d18:1-22:0)SM (12.5%). Calf brain SM was rich in species such as (d18:1-18:0)SM (40.7%), (d18:1-24:1)SM (17.1%), and (d18:1-20:0)SM (10.8%). 相似文献
333.
大数据环境下农业知识服务协作体系探索与实践 总被引:1,自引:0,他引:1
随着大数据环境下农业管理及科研创新的需求变化,快速、精准、深度、专业的信息知识服务的重要性日益凸显。为解决农业知识服务供需信息不对称问题、提升农业图书情报行业的整体竞争力和知识服务的精准供应,提出通过联合科研高校等农业机构,共同推动农业知识协作服务的开展。通过分析新环境下农业知识用户特征以及个性化需求,设计了农业体系知识服务协作体系的共建机制,详细介绍了协作体供给侧和服务侧的内容、服务模式及服务产品。最后基于协作体系目前的建设进展,提出了现存问题和改进建议,以期为我国农业领域知识协作服务以及跨领域知识协助服务提供参考和借鉴。 相似文献
334.
A cellular microRNA mediates antiviral defense in human cells 总被引:4,自引:0,他引:4
Lecellier CH Dunoyer P Arar K Lehmann-Che J Eyquem S Himber C Saïb A Voinnet O 《Science (New York, N.Y.)》2005,308(5721):557-560
In eukaryotes, 21- to 24-nucleotide-long RNAs engage in sequence-specific interactions that inhibit gene expression by RNA silencing. This process has regulatory roles involving microRNAs and, in plants and insects, it also forms the basis of a defense mechanism directed by small interfering RNAs that derive from replicative or integrated viral genomes. We show that a cellular microRNA effectively restricts the accumulation of the retrovirus primate foamy virus type 1 (PFV-1) in human cells. PFV-1 also encodes a protein, Tas, that suppresses microRNA-directed functions in mammalian cells and displays cross-kingdom antisilencing activities. Therefore, through fortuitous recognition of foreign nucleic acids, cellular microRNAs have direct antiviral effects in addition to their regulatory functions. 相似文献
335.
Individual components of Pinus pinea L. oil unsaponifiable matter isolated from seven Mediterranean populations were identified and quantified. P. pinea oil unsaponifiable matter contained very high levels of phytosterols (>or=4298 mg kg-1 of total extracted lipids), of which beta-sitosterol was the most abundant (74%). Aliphatic alcohol contents were 1365 mg kg-1 of total extracted lipids, of which octacosanol was the most abundant (41%). Two alcohols (hexacosanol and octacosanol), which are usually absent in common vegetable oils, were described for P. pinea oils. There were almost no differences in the total unsaponifiable matter of the seven Mediterranean populations studied. However, sterol and aliphatic alcohol contents showed some variability, with Tunisian and Moroccan populations showing very different and higher contents. 相似文献
336.
CHEN Yan-hui GAO Hui-fang WANG Sa LIU Xian-yan HU Qing-xia JIAN Zai-hai WAN Ran SONG Jin-hui SHI Jiang-li 《农业科学学报》2022,21(2):434-445
Recent investigations on pomegranate products have significantly increased and successfully drawn consumers’ attention to nutritional and medicinal values, promoting the pomegranate industry’s development worldwide. However, little information on pomegranates grown in China is available. Morphological and chemical characterizations of fruits and arils from 20 pomegranate cultivars in six regions of China were investigated. Combined with overall scores by principal component analysis, ’Yushiliu N... 相似文献
337.
AIM: To determine the effects of catestatin (CST) on calcium handling abnormalities and ventri-cular arrhythmia (VA) after myocardial infarction (MI) in rats. METHODS: The adult male SD rats (n=85) were randomly divided into sham group (n=20) and operation group (n=65). MI was induced by ligation of the left anterior descending coronary artery in operation group. The rats in sham group underwent pericardiotomy but without ligating the artery. The rats survived for 1 week after operation were randomly assigned to MI group and CST group. The rats in CST group was treated with CST (30 mg·kg-1·d-1, intraperitoneal administration) for 4 weeks, while saline was applied to the rats in sham group and MI group. The calcium imaging study was performed by loading isolated ventricular cardiomyocytes with Fura-2 AM. In the whole Langendorff-perfused hearts, the programmed electrical stimulation was used to induce action potential duration (APD) alternans and VA. The protein levels of ryanodine receptor 2 (RyR2), phosphorylated RyR2 (p-RyR2), calcium/calmodulin-dependent protein kinase II (CaMKII) and phosphorylated CaMKII (p-CAMKII) were determined by Western blot. RESULTS: Compared with sham group, the protein levels of p-RyR2 and p-CaMKII, the diastolic intracellular Ca2+ concentrations and the inducibility of VA were significantly increased, whereas the thresholds of Ca2+ transient (CaT) and APD alternans and the CaT amplitude were markedly decreased in MI group (P<0.01). Compared with MI group, the protein levels of p-RyR2 and p-CaMKII, the diastolic intracellular Ca2+ concentration and the inducibility of VA were significantly decreased, while the thresholds of CaT and APD alternans and the CaT amplitude were markedly increased in CST group (P<0.01). No significant difference of the protein expression of RyR2 and CaMKII among the 3 groups was observed (P>0.05). CONCLUSION: CST reduces the susceptibility to VA after MI via preventing calcium handling abnormalities. 相似文献
338.
This study was performed to evaluate the antioxidant and α-glucosidase inhibitory effects from the extract, fractions, and isolated compounds of sea buckthorn leaves. Six compounds, kaempferol-3-O-β-D-(6'-O-coumaryl) glycoside, 1-feruloyl-β-D-glucopyranoside, isorhamnetin-3-O-glucoside, quercetin 3-O-β-D-glucopyranoside, quercetin 3-O-β-D-glucopyranosyl-7-O-α-L-rhamnopyranoside, and isorhamnetin-3-O-rutinoside, were isolated from sea buckthorn leaf extracts. The butanol fraction (EC(50) = 1.81 μg/mL) along with quercetin 3-O-β-D-glucopyranoside (EC(50) = 1.86 μg/mL) had a higher DPPH radical-scavenging activity and showed stronger reducing power (OD(700) = 1.83 and 1.78, respectively). The butanol fraction (477 mg GAE/g) contained the highest amount of phenolic compounds and also the most powerful α-glucosidase inhibitory effect (86%) at 5 μg/mL. The results indicate that sea buckthorn leaf extracts could potentially be used for food additives and the development of useful natural compounds. 相似文献
339.
通过建立雪灾定量化评估模型,提供反映雪灾地理分布特征的风险区划,以实现快速、准确地对区域雪灾进行大范围监测和情景分析。根据青海基础地理信息数据,以县级行政为评价单元,提取了91.7 m×91.7 m栅格的坡度、坡向、草地类型等孕灾环境参数值,对雪灾形成的潜在地理条件进行分析;以雪灾规模、频率和密度等为致灾体危险性指标;选取人口密度、经济密度、交通密度以及土地资源丰富度等社会经济背景数据为承灾体易损性评价指标。基于ArcGIS平台,应用数学综合评价法建立了基于空间统计分析的青海牧区雪灾定量化综合风险评估模型,在使用相关基础图件和资料基础上,对属性和图形数据库进行操作,分别得到雪灾的孕灾环境敏感性、灾害危险性、承灾体易损性评价图层,再经过图层叠加、斑块合并以及等级划分等操作,最终得到青海省雪灾风险区划图。研究结果可对牧区越冬前采取有效风险管理以减轻损失,保障草地畜牧业的可持续发展具有重要意义;并且为当地政府及防灾救灾部门制定灾前减灾规划和灾后救助决策提供科学依据,研究方法对于全国其他省区的雪灾风险评估也具有重要参考价值。 相似文献
340.
番茄新品种江蔬1号的选育 总被引:1,自引:0,他引:1
江蔬 1号番茄是以自交系 4170p和C94 32 2 4杂交选育而成的一代杂种。属中早熟 ,有限生长类型 ,抗ToMV、枯萎病、叶霉病。果实圆形、红色 ,果面光滑 ,果皮厚 ,耐贮运 ,商品率高。单果质量 2 10 g ,一般春季大棚每 6 6 7m2 产量 45 0 0kg左右 ,高产可达 5 5 0 0kg ,适于早春大棚栽培及露地地膜覆盖栽培。 相似文献