Subjects: Biology >> Botany >> Applied botany submitted time 2022-03-18 Cooperative journals: 《广西植物》
Abstract： In order to provide new data for clarification of the generic relationship in Hypoxidacae, morphology, ultrastructure, and anatomy of leaf from five species in Hypoxidaceae were investigated using microscope, scanning electronic microscope (SEM), and paraffin section. It turned out that there were five points of views as below ： (1) Three types of leaf shapes were characterized, including small-even, middle-wave, and large-plicate. (2) Trichomes were single-celled and uniseriate, and grouped into pilose, strigose, and stellate. (3) Shapes of leaf epidermal cells were hexagon and pentagon, while stomata was paracytic and elliptic with a correlation between size and density. (4) Sculptures of wax in epidermis was classified into smooth, granular, scales, and crust. (5) Leaf anatomy revealed two types of vascular bundles and relevence between thickness of epidermis and size of epidermal cells. Based on comparative morphology and anatomy of leaf, it is suggested that complex of some characters would be helpful for understanding of generic relationships in Hypoxis L., Curculigo Gaertn. and Molineria Colla., while other characteristics for species identifications.
Subjects: Biology >> Botany >> Applied botany submitted time 2021-06-02 Cooperative journals: 《广西植物》
Abstract： Secondary coniferous and broad-leaved mixed forests is very common in subtropical regions. Studying the community succession characteristics and regeneration rules of the secondary coniferous and broad-leaved mixed forests will provide a scientific basis for vegetation restoration and forest management in this area. Using two datasets (2013 and 2018) from a permanent 1 hm2 secondary coniferous and broad-leaved mixed forest plot in DBS, we analyzed the dynamics changes of tree species composition, community species diversity, species important values, and size class structure and so on. The results were as follows: (1) Species richness and individual numbers were significantly reduced in the community during 2013-2018 (P<0.05); (2) In the plot, 1 505 individuals DBH≥1 cm died, with an average annual mortality rate of 6.40%, and 71 new individuals recruited, with an average annual recruitment rate of 0.35%; (3) The community species diversity indexes declined significantly (P<0.05), of which Margalef richness index changed greatly, decreased by 25.03%, and Shannon-Wiener index decreased by 11.88%; (4) The dominant position of evergreen broad-leaved tree species were strengthening, while coniferous tree species were gradually reduced; (5) During the five years, the proportion of large and medium size class plants gradually increased, while the proportion of small size class plants gradually decreased. In general, the species composition and structure dynamics of the secondary coniferous and broad-leaved mixed forest community in DBS changed significantly during 2013-2018. The community is in a rapid succession stage from secondary coniferous and broad-leaved mixed forest to evergreen broad-leaved forest.
Subjects: Biology >> Botany >> Applied botany submitted time 2020-01-12 Cooperative journals: 《广西植物》
Abstract：利用石蜡切片技术观察了兰科单型属竹叶兰属的花粉团发育过程，包括花形态解剖特征、8个花粉团的形成机制、花药壁发育模式、小孢子发生及雄配子体发育等特征，为该属复杂的系统亲缘关系提供胚胎学证据，结果如下。成熟花药有两个药室，每个药室有4个一簇金色的花粉团，被白色花药帽。早期花药原基分化出的一对并列侧生药室，每个药室中央小孢子囊分化出一对纵横交错的不育隔膜组织将其分割为4个次生小孢子囊，最后发育为4个花粉团。花药成熟时，由于每个药室内的花粉团间的隔膜组织发生不彻底降解，导致4个花粉团在花药开裂处粘合成一簇。发育完好的花药壁共有6 ~ 7层，由外到内为表皮、3 ~ 4层药室内壁、中层和双核绒毡层，符合多层型花药壁的发育模式。花药成熟时，表皮退化，纤维性加厚发生在3 ~ 4层药室内壁，中层和绒毡层彻底降解。小孢子母细胞通过同时型胞质分裂产生了正四面体型、左右对称、十字交叉型排列的小孢子四分体。小孢子四分体继续保持在同一胼胝质内完成了雄配子体发育，形成了2 - 细胞型的四合花粉。四合花粉两两或松散或紧密排列，构成了粉质花粉团。在前人的研究基础上，本文证实、补充并分析了竹叶兰属的花粉团发育特征，为该属的亲缘关系提供了胚胎学证据。
Subjects: Biology >> Bioengineering submitted time 2019-03-05 Cooperative journals: 《中国生物工程杂志》
Abstract： Objective: A new material with ultra-large surface area named nano-forest is prepared by Micro-Electro-Mechanical System(MEMS) processing technology. Based on this material, a new microfluidic chip for point-of-care test with simple operation, rapid detection and high sensitivity is created. Methods: The fabrication of nano-forests in micro-channel on quartz substrate mainly includes: cleaning and drying of quartz substrate; spinning polyimide(PI) coating; re-spinning phenolic resin photoresist on PI coating; photolithography to expose the channel; treating the PI layer with oxygen plasma and argon plasma to synthesize nano-fiber forests structure; nano-fiber-quartz nanoforests are realized by using nano-fiber forests as nanomasks in anisotropic etching of quartz by using reactive ion etching (RIE); the micro-channel with nano-forests structure inside is achieved after removing upper nanofiber forests structure and phenolic resin photoresist coating.The height, width, density and specific surface area of nano-forest are studied and analyzed by scanning electron microscope(SEM). Optical properties are tested by ultraviolet-visible spectrophotometer. The driving force is characterized by the flow rate of PBS solution.The sensitization effect is evaluated by saturated fluorescence test through antibody and AbFluor 680 dye-labeled secondary antibody. The sample pad, bond pad, micro-channel with nano-forests structure, nitrocellulose membrane and absorbent material are assembled on PMMA substrate in sequence, which is the microfluidic chip. The chip based on the sandwich format with a polyclonal antibody and a AbFluor 680 dye-labeled secondary antibody is used to detect ricin toxin(RT). Results: The scanning electron microscope shows that the nanofiber forests structure is formed on quartz substrate after oxygen plasma and argon plasma bombardment. The single nanofiber is upright on the substrate with a diameter of about 50-100 nm, a height of 1.8 um and a density of about 20/μm2. The quartz nano-forests structure can be obtained after RIE with nano-fibre forests structure as mask and resist removal. The single structure is shaped like a cone. The diameter of the cone bottom is about 100-200 nm, the height is about 1.0 um, the density is about 10/μm2, and the surface area to bottom area is more than 5:1. Self-driven test provides information of the flow rate of PBS is to be about 5 mm/s in the micro-channel on the basis of nano-forests structure. The transmittance of the channel is 89.5%at 680 nm wavelength. It shows that the channel has good transmittance, which makes the loss of excitation light or emission light much less, and is conducive to the sensor capturing more signals. With same surface modification, the planar quartz structure has shortcomings of short lasting effect time and low saturation fluorescence intensity. To the contrary, nano-forests structure with ultra-large surface area has a good sensitization effect in the test. RT can be detected sensitively based on the significantly fluorescent intensity.The linear range of detection is from 10 pg/mL to 6250 pg/mL and the limit of detection (LOD) is lower than 10 pg/mL. Conclusion: The nano-forests structure with good optical properties reduces the requirements of sensor and also makes the choice of fluorescent dyes wider.The three-dimensional structure of the nano-forest has an ultra-large surface area, which increases the amount of antibody compared to the planar structure, and thus improves the sensitivity of detection greatly. Compared with the immunochromatographic test strip, the microfluidic chip has an advantage of high sensitivity, thus the quantitative analysis can be realized within a certain range. Most microfluidic chips require complex equipments to provide driving force, which will make them costly and bulky. Driven by the capillary force, the chip with nano-forests structure inside makes the detection simple and fast. Combined with the miniaturized detection terminal, the platform can be miniaturized, portable, and automated, achieving the goal of simple, fast and efficient analysis. These characteristics make the chip an ideal candidate for the development of rapid detection methods.
Subjects: Biology >> Zoology submitted time 2018-12-24 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究全混合日粮粗饲料水平对奶牛挑食行为、瘤胃内环境及血清指标的影响。选用12头泌乳中期[泌乳时间（119±26） d]经产荷斯坦奶牛[体重（629±46） kg]，随机分为4组，每组中1头安装瘤胃瘘管，按4×4拉丁方设计，饲喂粗饲料水平分别为40%、50%、60%和70%（干物质基础）的4种全混合日粮。共进行4期动物试验，每期试验21 d。结果表明：饲粮粗饲料水平对奶牛挑食行为有显著（P40%时，奶牛喜食粒度0.05）。随饲粮粗饲料水平的增加，瘤胃液外流速度和瘤胃固相外流速度显著线性增加（P0.05）；血清胰岛素样生长因子-1（IGF-1）含量显著线性增加（P<0.01），瘦素（LEP）和非酯化脂肪酸（NEFA）含量有线性增加趋势（0.05≤P<0.10），血清生长激素（GH）和胰岛素（INS）含量有线性降低的趋势（0.05≤P<0.10）。综上所述，饲粮粗饲料水平是影响奶牛挑食行为、瘤胃内容物及血清指标的重要因素。
Subjects: Biology >> Bioengineering submitted time 2017-11-21 Cooperative journals: 《中国生物工程杂志》
Abstract：为了解除微生物发酵生产丙酸过程中代谢产物（丙酸）对菌体生长的抑制作用，以实验室保藏的产酸丙酸杆菌（耐30g/L丙酸）为出发菌株P-0，通过丙酸压力筛选获得了一株耐10g/L丙酸的产酸性能良好的菌株P-10，降低了发酵过程中丙酸对菌体生长的抑制作用。菌株P-10做摇瓶发酵，发酵周期168h，丙酸浓度为49.66 g/L，产酸速率为0.30g/L·h，较出发菌株P-0提高了53.04%；7L发酵罐实验表明，菌株P-10发酵周期168h，丙酸浓度为55.63g/L，产酸速率0.33g/L·h。同时对菌株P-10做二次接种实验，结果表明，84h为二次接种最适时间段，且84h进行二次接种时，丙酸浓度提高了17.77%，二次接种实验不但有利于有机酸的积累，而且可以提高菌株的产酸能力和耐酸能力；经过选育的菌株P-10具有优良的产酸稳定性，有利于菌种的工业化生产和应用，同时对后续的发酵分离耦合具有重要意义。
Subjects: Biology >> Bioengineering submitted time 2017-11-21 Cooperative journals: 《中国生物工程杂志》
Abstract：为了解除微生物发酵生产丙酸过程中代谢产物（丙酸）对菌体生长的抑制作用，以实验室保藏的产酸丙酸杆菌（耐30g/L丙酸）为出发菌株P-0，通过丙酸压力筛选获得了一株耐10g/L丙酸的产酸性能良好的菌株P-10，降低了发酵过程中丙酸对菌体生长的抑制作用。菌株P-10做摇瓶发酵，发酵周期168h，丙酸浓度为49.66 g/L，产酸速率为0.30g/L·h，较出发菌株P-0提高了53.04%；7L发酵罐实验表明，菌株P-10发酵周期168h，丙酸浓度为55.63g/L，产酸速率0.33g/L·h。同时对菌株P-10做二次接种实验，结果表明，84h为二次接种最适时间段，且84h进行二次接种时，丙酸浓度提高了17.77%，二次接种实验不但有利于有机酸的积累，而且可以提高菌株的产酸能力和耐酸能力；经过选育的菌株P-10具有优良的产酸稳定性，有利于菌种的工业化生产和应用，同时对后续的发酵分离耦合具有重要意义。
Subjects: Biology >> Zoology submitted time 2017-10-10 Cooperative journals: 《动物营养学报》
Abstract：限制性氨基酸研究是泌乳奶牛研究的一个热点之一，关于其影响乳蛋白合成途径而进行的一系列体内外研究表明：底物效应可能不是主要原因，更重要的是氨基酸及其构成作为信号因子对神经内分泌和细胞内信号通路的影响。本文从乳蛋白合成的影响因素入手，概括了氨基酸供给、激素分泌及二者相互作用对乳蛋白合成的调节，以期为阐明氨基酸供给影响乳蛋白合成的途径提供一定理论参考。
Subjects: Biology >> Zoology submitted time 2017-10-10 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究全混合日粮（TMR）饲喂泌乳奶牛群摄入养分偏离的原因分析及对生产性能的影响。选取30个高产牛群，每个牛群采样5 d。采取牛群TMR及剩料样品，进行养分分析和颗粒分级评定，计算各指标的变异系数。记录产奶量，取奶样测乳成分。多元线性回归分析养分、颗粒的变异系数与牛群生产性能的关系。结果表明：30个牛群饲喂的TMR产奶净能（NEL）和粗蛋白质（CP）、中性洗涤纤维（NDF）、酸性洗涤纤维（ADF）、微生物蛋白质（MCP）、瘤胃非降解蛋白质（RUP）、瘤胃能氮平衡（RENB）、小肠可消化粗蛋白质（DCPSI）、钙（Ca）含量分别为6.56 MJ/kg和16.22%、35.71%、21.38%、77.84 g/kg、92.15 g/kg、14.77 g/kg、104.04 g/kg、1.43%，其中高于配方目标的指标有NDF(1.94%)、Ca(0.57%)、RUP（5.03 g/kg）、RENB（6.95 g/kg），低于配方目标的指标有CP(-0.36%)、ADF(-1.54%)、NEL(-0.12 MJ/kg)、MCP(-7.71 g/kg)、DCPSI(-2.12 g/kg)（正值表示提高，负值表示降低）。观测期内，RUP[（16.26±7.10）%]、MCP[(22.78±13.38)%]、RENB[(64.29±34.29)%]3种养分的变异系数大于10%，其他养分的变异系数均小于10%。长、中、短、细4类颗粒含量的变异系数分别为(15.78±9.25)%、(9.12±7.86)%、(6.00±4.00)%、(11.15±9.62)%。回归分析表明，TMR养分和颗粒度变异影响产奶量和乳成分，NEL变异系数每升高1个百分点，产奶量下降3.662 kg/d；长颗粒变异系数每升高1个百分点，产奶量下降0.124 kg/d，乳脂率升高0.012%。结果提示，TMR饲喂泌乳奶牛摄入养分因投料不准确、加工质量不稳定、搅拌不均匀、挑食等与配方养分产生差异。TMR加工质量稳定性影响到产奶量和乳成分，其中NEL、DCPSI、RENB的变异影响产奶量，长颗粒变异影响产奶量和乳脂率。
Subjects: Biology >> Bioengineering submitted time 2017-07-24 Cooperative journals: 《中国生物工程杂志》
Abstract： Screening and Application of Acid-resistant Strains of Propionibacterium acidipropionici
Subjects: Biology >> Bioengineering submitted time 2017-07-24 Cooperative journals: 《中国生物工程杂志》
Abstract：为获得具有免疫原性的TK1重组蛋白。通过构建能够表达TK1蛋白的重组菌BL21-pET32a-TK1,采用大肠杆菌pET32a表达系统，优化IPTG浓度、诱导温度、诱导时间使BL21-pET32a-TK1重组菌表达目的蛋白的作用条件最佳。表达产物用镍离子亲和层析纯化获得TK1蛋白，并用SDS-PAGE和western blot进行检测。用TK1重组蛋白免疫BALB/c小鼠制备单克隆抗体，检测蛋白免疫原性。实验结果表明：成功构建能够表达TK1蛋白的重组菌BL21-pET32a-TK1，在37℃条件下，IPTG浓度为0.2mM/L、诱导6h时重组蛋白TK1表达量最高。镍离子亲和层析梯度洗脱在80mM咪唑条件下TK1蛋白纯度最大，灰度分析为87.3%，浓缩后蛋白浓度为5.96mg/ml。用该蛋白制备杂交瘤共获得10株稳定分泌TK1抗体的阳性单克隆细胞株，表明TK1重组蛋白具有较好的免疫原性。本实验成功获得可溶性、抗原活性高、免疫原性强的TK1重组蛋白，为肿瘤科学及临床应用研究提供物质支撑。
Hits
Hits
Downloads
Comment