闽西北稻区"晚改中"避蚊减害技术研究与应用

针对闽西北海拔300-500m的单、双季水稻混栽区稻瘿蚊危害重、单季稻三代稻瘿蚊危害突出的情况,通过研究提出“晚改中”的依据和技术,在正常年份下,把以往5月份播种的单季稻的播种期提早到4月5日前,就可以有效地避开三代稻瘿蚊的危害,而不必提早到3月20日前,与农民农时操作习惯更吻合,农民更易接受采用。     

光催化与纯紫外工艺对船舶压载水微藻的处理效果比较

分析光催化和纯紫外工艺对控制处理压载水中10～50μm藻类的影响,比较了压载水中10～50μm藻类的去除率、种类变化、绿藻和硅藻去除率以及硅藻种类数的变化,结果显示光催化工艺对10～50μm藻类的去除效果要好于纯紫外工艺。两种工艺对10～50μm藻类的即时去除率均可以达到96.0%以上,压载数日后排放则效果更佳。研究发现两种工艺对硅藻的处理效果不如绿藻。并且压载水盐度会影响压载水处理工艺的效果。     

不同林龄杉木氮素的获取策略

为了探讨不同林龄杉木人工林氮素获取策略,选择了江西千烟洲森林生态研究站红壤区的3种林龄杉木人工林(5年生幼龄林、13年生中龄林和30年生成熟林)作为研究对象,利用稳定性同位素~(15)N示踪技术研究了它们的氮素吸收策略。结果表明,杉木对硝态氮的吸收受林龄影响,成熟林的吸收速率最高,为(5.72±0.24)μg N g~(-1)干重h~(-1),而中龄林和幼龄林的吸收速率相当,分别为(1.57±0.13)μg N g~(-1)干重h~(-1)和(2.36±0.22)μg N g~(-1)干重h~(-1)。幼龄林((34.33±1.20)μg N g~(-1)干重h~(-1))和成熟林((34.18±2.32)μg N g~(-1)干重h~(-1))对铵态氮的吸收速率相似,均显著高于中龄林((23.33±1.39)μg N g~(-1)干重h~(-1))。杉木对甘氨酸的吸收不受林龄的影响。3种年龄的杉木均对铵态氮表现出强的获取能力,其中成熟林杉木对硝态氮的获取能力明显弱于对铵态氮的获取,但却强于对甘氨酸的获取。这样的结果反映了林龄能影响杉木人工林对无机氮的吸收,但未影响对有机氮的吸收;杉木偏好吸收铵态氮,对硝态氮和甘氨酸的吸收很少。如果能把氮素形态考虑进对杉木人工林的施肥管理当中,那么可能会极大地改善杉木的生产力。     

关于周口店第15地点石器类型和加工技术的研究

在周口店第 15地点经过加工的石器中 ,刮削器占近 93%。其它石器类型包括砍砸器、尖刃器、石锥、凹缺器、雕刻器和薄刃斧。石器由锤击加工。绝大多数标本向一面加工。石片石器多为正向加工。大多数石器个体很小 ,形态不规则 ,修疤呈鳞状 ,深浅、大小不一。少数标本的修疤浅平、规则而平行。统计分析显示在各类器型之间存在着明显的大小与加工上的区别。单边刃刮削器的各亚型之间在大小、加工长度和深度以及刃角和刃形诸方面不存在明显的差异 ,说明这些刮削器在刃口形态 (直、凸与凹 )方面的的变异主要取决于毛坯的原始形态 ,而非代表类型与功能的不同。变量相关分析揭示石器的大小与加工程度和原坯的大小与形态紧密相关。     

基因工程技术在食品品质改良中的应用

概述了用基因工程技术改良食品的食用品质,提高食品加工性能的研究和应用现状。     

两个水稻品种(系)酵母双杂交cDNA文库的构建和比较分析

"武育粳3号"和"KT95-418"为两个遗传背景基本一致而对水稻条纹叶枯病表现为明显抗性差异的粳稻(Oryza sativa L.ssp. japonica)品种(系).利用SMART技术合成双链cDNA后,通过SfiⅠ酶切位点将cDNA片段定向插入到改造的载体NpGADT7中,构建了两品种(系)水稻的酵母双杂交cDNA文库.检测结果表明:所构建的两个文库库容量均大于1.0×106 cfu;初始文库滴度分别为1.0×1010 cfu/mL和5.0×1010 cfu/mL,扩增文库滴度均为1.0×1011 cfu/mL;两文库重组率均大于95 %;"武育粳3号"文库cDNA插入片段长度集中分布在700 bp～800 bp之间,"KT95-418"集中分布在750 bp～1 000 bp之间;小规模测序结果表明两文库中全长基因的比例均超过60 %.两品种(系)水稻酵母双杂交cDNA文库的构建为筛选分离抗病相关的变异基因及开展寄主与水稻条纹病毒(Rice stripe virus, RSV)互作的研究奠定了基础.     

A practical approach in bioreactor scale‐up and process transfer using a combination of constant P/V and vvm as the criterion

Bioreactor scale‐up is a critical step in the production of therapeutic proteins such as monoclonal antibodies (MAbs). With the scale‐up criterion such as similar power input per volume or O₂ volumetric mass transfer coefficient ( ), adequate oxygen supply and cell growth can be largely achieved. However, CO₂ stripping in the growth phase is often inadequate. This could cascade down to increased base addition and osmolality, as well as residual lactate increase and compromised production and product quality. Here we describe a practical approach in bioreactor scale‐up and process transfer, where bioreactor information may be limited. We evaluated the sparger and (CO₂ volumetric mass transfer coefficient) from a range of bioreactor scales (3–2,000 L) with different spargers. Results demonstrated that for oxygen is not an issue when scaling from small‐scale to large‐scale bioreactors at the same gas flow rate per reactor volume (vvm). Results also showed that sparging CO₂ stripping, , is dominated by the gas throughput. As a result, a combination of a minimum constant vvm air or N₂ flow with a similar specific power was used as the general scale‐up criterion. An equation was developed to determine the minimum vvm required for removing CO₂ produced from cell respiration. We demonstrated the effectiveness of using such scale‐up criterion with five MAb projects exhibiting different cell growth and metabolic characteristics, scaled from 3 to 2,000 L bioreactors across four sites. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1146–1159, 2017     

菊花不同花期及花序不同部位香气成分和挥发研究

以切花菊品种‘神马’为试材,采用顶空-固相微萃取和气相色谱-质谱联用(GC/MS)技术,分别测定菊花不同花期及花序不同部位的香气成分种类和含量,并利用生物显微镜观察花瓣的表皮细胞和横切面组织细胞的结构特征。结果表明:(1)菊花花蕾期共检测到香气成分24种,始花期31种,盛花期43种,终花期22种;随着花朵的开放和凋谢,酮类、萜烯类和醇类化合物的含量呈先上升后下降的趋势,在盛花期含量达到最高,而酯类、醛类和杂环类化合物则呈持续下降的趋势。(2)盛花期,在舌状花中共检测到香气成分种类31种,在管状花中共检测到50种;舌状花对菊花香气的贡献比管状花大;菊花舌状花由内轮向外轮香气成分种类变化不大,但是同类香气成分含量的变化出现由内轮向外轮逐渐减少的趋势。(3)异环柠檬醛、桉叶醇、α-蒎烯、β-金合欢烯和石竹烯等化合物可能为菊花的主要特征香气成分。(4)显微观察结果表明:舌状花的香气可能是通过表皮细胞间隙释放的,上表皮是菊花释放香气的主要部位。     

Process analytical technology case study,part III: Calibration monitoring and transfer

This is the third of a series of articles detailing the development of near-infrared spectroscopy methods for solid dosage form analysis. Experiments were conducted at the Duquesne University Center for Pharmaceutical Technology to develop a system for continuous calibration monitoring and formulate an appropriate strategy for calibration transfer. Indcators of high-flux noise (noise factor level) and wave-length uncertainty were developed. These measurements, in combination with Hotelling’s T² and Q residual, are used to continuously monitor instrument performance and model relevance. Four calibration transfer techniques were compared. Three established techniques, finite impulse response filtering, generalized least squares weighting, and piecewise direct standardization were evaluated. A fourth technique, baseline subtraction, was the most effective for calibration transfer. Using as few as 15 transfer samples, predictive capability of the analytical method was maintained across multiple instruments and major instrument maintenance.     

Dodonaea viscosa var. angustifolia leaf: New source of polysaccharide and its anti-oxidant activity

Ultrasonic technology was applied for polysaccharide extraction from the leaves of Dodonaea viscosa and response surface methodology (RSM) was used to optimize the effects of processing parameters on polysaccharide extraction yield. Three independent variables were extraction time (X₁), extraction temperature (X₂) and ultrasonic power (X₃), respectively. The statistical analysis indicated the independent variables (X₁, X₂, X₃), the quadratic terms (X₁₁ and X₃₃) and the interaction terms (X₁X₂, X₁X₃, X₂X₃) had significant effects on the yield of polysaccharides (P < 0.05). The optimal extraction conditions of D. viscosa leaf were determined as follows: extraction time 50.54 min, extraction temperature 85 °C and ultrasonic power 400 W. Under these conditions, the experimental yield of polysaccharides was 9.455 ± 0.24%, which was agreed closely with the predicted value (9.398%). The evaluation of anti-oxidant activity suggested that the polysaccharide exhibited significant protection against DPPH and hydroxyl radicals and could be explored as a nutraceutical agent.