生地高产高效人工栽培技术

生地,是我国重要的中药材植物之一,全草均可入药.其地下茎具有重要食疗作用,是一种菜药兼用的野生保健蔬菜.着重介绍了生地的特征特性及高产高效人工栽培要点.     

泌阳县小麦高产栽培技术

小麦是我国主要粮食作物,其产量在粮食总产量中占有非常重要的比例,提升小麦总产量是保证民生问题的关键。如何能增加小麦高产、超高产的收获产量,这需要在小麦栽培技术上进行探索和创新。本文便针对于小麦高产超高产栽培技术进行探讨。     

无公害西红柿高产栽培技术

西红柿属喜温类蔬菜,无限生长型,生育期可长达6-10个月(设施良好的大型温室可达到12个月以上),植株高大(10米以上)。一般可以定植后70-80天左右采收,果皮较厚,有极其优良的储运性能。且叶甜醇美,色泽鲜亮(亮红色)。本文主要从播前准备、培育壮苗、定植与管理、肥水管理、病虫害防治、采收与销售等方面总结了无公害西红柿高产栽培技术,为农民朋友提供技术参考。     

浅谈大豆高产栽培技术

中国是大豆发源地,大豆一直是我国主要的粮食与油料作物之一。但是近年来,我国在大豆高产优质品种选育及配套高产高效栽培技术的研究、试验与推广上发展缓慢,单产水平不高,导致种植大豆比较效益低。尤其是我国耕地面积在不断的减少,人口在不断的膨胀,大豆的质量和产量直接的影响着我国经济的发展,如何改变这样的局面,将是我们面临的研究课题。本文针对大豆栽培技术进行了详细的阐述。     

双孢菇高产栽培技术要点

双孢菇栽培技术比较简单 ,易于掌握 ,栽培原料以小麦秸、牛马粪等可再生资源为主 ,生产成本低 ,生产周期短 ,效益高。 0 .0 0 67ｈａ温室即可产鲜菇50 0ｋｇ ,获产值 2 0 0 0～ 2 50 0元 ,农民纯收入 10 0 0～150 0元 ,相当于 0 .13～ 0 .2ｈａ小麦的收入。在几年的栽培实践中 ,我们总结以下技术要点。1　栽培时间本地区一般在中小温室栽培 ,小雪后温度过低 ,如果不采取人工加温措施双孢菇立即停止生长。在此之前如果不能生产出 3潮菇 ,获得较高的前期产量 ,等到第二年春季温度上升后再产菇 ,其总产量和销售价格降低 ,效益往往较差。 8月 2 …     

高油大豆高产栽培技术

随着科技的不断发展,目前大豆的生产技术正在逐渐的被更新,其生产的效益也在不断的增加,尤其是高油大豆的生产,本文主要是通过对高油大豆的实际考察总结出一套高油大豆较为完整的高产技术。     

双孢蘑菇优质高产栽培技术

我们于1994年引进台湾双抱蘑菇菌种及相关的栽培技术,结合本地区的具体情况,经过大面积栽培试验,生物转化率为35％左右,最高可达50％,现将此技术介绍如下：1栽培料的质量要求稻草：新鲜并且干燥,水分含量18％以下。硫酸按：白色结晶,含氮量21％。尿素：白色结晶,含氮量46％。过磷酸钙：黄褐色或灰色粉末,PZq含量15％。轻质碳酸钙：白色至灰色粉末,op含量95％以上,pH7．0～8．so熟石灰：白色粉末,pH11Lll。大米糠：黄白色粉末,无酸臭味,且不得结决。2菇房结构和栽培床的搭建①菇房结构：利用空闲民房作菇房,也可建成大棚式…     

冬小麦高产高效栽培投资风险预测模拟

在产量形成规律及投入产出效益规律基础上,建立了冬小麦高产高效栽培投资风险预测模拟模型.并以Window XP为平台,采用VB(Visual Basic)语言编程,建立了相应的可视化模拟系统。通过模拟,生产者可以预测在当时的市场价格下小麦生产的投资风险大小,并预测生产的最大利润及小麦产量.模拟系统还可以用于决策部门对市场价格的宏观调控,如果希望增加农民收入,鼓励农民生产粮食,决策部门可以先定单位面积小麦生产利润值,通过模拟得适宜的肥粮价比,用来调控市场价格,     

四川玉米高产高效栽培的数学模拟

采用正交旋传组合设计,建立了四川玉米川单9号产量与密度、施N、施P和施K量的二次回归模型。根据数学中函数极大值的概念和农业技术经济学边际效应理论,分别求出当其中三因素处于平均水平时,玉米最高产量和最大经济效益时的密度、施N、施P和施K量。     

冬小麦高产优质高效栽培决策模拟研究

在产量和品质形成规律及投入产出效益规律基础上,应用模糊集方法,构建了一个综合的冬小麦高产优质高效栽培优化决策模拟模型.并以Window XP为平台,采用VB(Visual Basic)语言编程,建立了相应的可视化决策支持系统.实现了在不同时空、自然、社会、经济、技术条件下,进行多目标、可综合、可选择、可调控的冬小麦田间水肥管理决策的目标.通过检验证明模拟模型是可行的.     

姬松茸栽培料配方筛选及栽培工艺的研究

对姬松茸栽培料配方进行了优化选择,并系统地研究了姬松茸的栽培工艺。结果表明:最佳栽培料配方为玉米芯4.5kg/m2、稻草5.25kg/m2、牛粪4.65kg/m2、麸皮1.8kg/m2、石灰0.075kg/m2、过磷酸钙0.375kg/m2、尿素0.15kg/m2、石膏0.15kg/m2,其产量达到6.29kg/m2,显著高于对照。栽培料最佳厚度为17.5cm,播种量为6%;播种方式采用2层播,垄式覆土。     

动物细胞培养用生物反应器及相关技术

动物细胞大量培养是生产生物制品的重要途径,它用到的关键设备是生物反应器。根据培养细胞、培养载体、培养液混合方式的不同,生物反应器主要有搅拌式、气升式、中空纤维式、回转式等,其中搅拌式规模最大。回转式是NASA于20世纪90年代中期开发的一种新型生物反应器,被誉为空间生物反应器,可用于组织工程研究。与生物反应器配套的技术主要有灌注、微载体、多孔微球、转入抗凋亡基因等,可以有效地提高细胞密度,增加生物制品产量,提高质量。今后生物反应器研制主要朝两个方向发展:一是,以高密度培养动物细胞生产蛋白质药物为目的,二是以三维培养动物细胞(主要是人类细胞)再生组织或器官为目的。     

High Resolution Techniques for Study of Human Centromeric Heterochromatin

A high resolution procedure for analyzing human centromeric heterochromatin is described. The combined use of decondensation agents of pericentromeric heterochromatin and electron microscopy of whole mounted chromosomes allows a more precise identification of centromere and pericentromeric regions.     

High yield production of extracellular recombinant levansucrase by Bacillus megaterium

In this study, a high yield production bioprocess with recombinant Bacillus megaterium for the production of the extracellular enzyme levansucrase (SacB) was developed. For basic optimization of culture parameters and nutrients, a recombinant B. megaterium reporter strain that produced green fluorescent protein under control of a vector-based xylose-inducible promoter was used. It enabled efficient microtiter plate-based screening via fluorescence analysis. A pH value of pH?6, 20 % of dissolved oxygen, 37 °C, and elevated levels of biotin (100 μg?L^?1) were found optimal with regard to high protein yield and reduced overflow metabolism. Among the different compounds tested, fructose and glycerol were identified as the preferred source of carbon. Subsequently, the settings were transferred to a B. megaterium strain recombinantly producing levansucrase SacB based on the plasmid-located xylose-inducible expression system. In shake flask culture under the optimized conditions, the novel strain already secreted the target enzyme in high amounts (14 U?mL^?1 on fructose and 17.2 U?mL^?1 on glycerol). This was further increased in high cell density fed-batch processes up to 55 U?mL^?1, reflecting a levansucrase concentration of 0.52 g?L^?1. This is 100-fold more than previous efforts for this enzyme in B. megaterium and more than 10-fold higher than reported values of other extracellular protein produced in this microorganism so far. The recombinant strain could also handle raw glycerol from biodiesel industry which provided the same amount and quality of the recombinant protein and suggests future implementation into existing biorefinery concepts.     

High yield chromatographic purification of enzymatically produced tyrosine fructosyl ester

The synthesis of L-tyrosine fructosyl ester, from fructose and L-tyrosine methyl ester, was carried out by a transesterification reaction catalyzed by α-chymotrypsin in water without any organic cosolvent. The yield was optimized by regulating the pH?of the reaction medium and a maximum yield of 63% was obtained. A two-step process of tyrosine fructosyl ester purification was proposed using adsorbent resin and activated carbon. Different elutions and supports easily applicable to industrial process have been studied. Solutions of tyrosine fructosyl ester with a 96% purity and 70% recovery yield were obtained by chromatography on a column of acrylic polyester resins with a solution of 0.5?M NaCl as eluant.     

High yield production process for Shigella outer membrane particles

Gram-negative bacteria naturally shed particles that consist of outer membrane lipids, outer membrane proteins, and soluble periplasmic components. These particles have been proposed for use as vaccines but the yield has been problematic. We developed a high yielding production process of genetically derived outer membrane particles from the human pathogen Shigella sonnei. Yields of approximately 100 milligrams of membrane-associated proteins per liter of fermentation were obtained from cultures of S. sonnei ΔtolR ΔgalU at optical densities of 30-45 in a 5 L fermenter. Proteomic analysis of the purified particles showed the preparation to primarily contain predicted outer membrane and periplasmic proteins. These were highly immunogenic in mice. The production of these outer membrane particles from high density cultivation of bacteria supports the feasibility of scaling up this approach as an affordable manufacturing process. Furthermore, we demonstrate the feasibility of using this process with other genetic manipulations e.g. abolition of O antigen synthesis and modification of the lipopolysaccharide structure in order to modify the immunogenicity or reactogenicity of the particles. This work provides the basis for a large scale manufacturing process of Generalized Modules of Membrane Antigens (GMMA) for production of vaccines from gram-negative bacteria.     

High yield regioselective monobenzyloxycarbonylation of secondary alcohols in glycopyranoside series

The regioselective monobenzyloxycarbonylation of secondary alcohols in methyl 6-O-(4-methoxytrityl)-alpha-D-manno-, gluco- and galactopyranoside has been achieved in high yields (74-85%) by using benzyl chloroformate in the presence of 4-dimethylaminopyridine and/or 1,4-diazabicyclo[2.2.2]octane.     

High yield synthesis of tentoxin, a cyclic tetrapeptide.

Tentoxin is a naturally occurring phytotoxic cyclic tetrapeptide excreted by fungi of the Alternaria alternata family. The four total syntheses of tentoxin published to date give poor total yields, mainly owing to two difficulties, the introduction of the dehydro amino acid and more especially the cyclization step. Here we describe a method that stereospecifically introduces Z-dehydrophenylalanine (deltaZPhe) by a modified Erlenmeyer aldolization reaction. The linear tetrapeptide, Boc-R1Ala-Leu-R2deltaZPhe-G1y-OMe (R1, R2: CH3, 14CH3), the precursor of tentoxin, was obtained in a 72% yield from Boc-Leu-Gly-OH. This linear tetrapeptide, labelled with carbon-14, was used for a comparative study of four cyclization reagents DPPA, DCC-PfpOH, HBTU and HATU. This last was the most effective and gave tentoxin in a 81% cyclization yield. The activated ester formed with this reagent displayed an enhanced capacity for cyclization, permitting cyclization in concentrated medium (10 mM). This new synthetic route gave tentoxin in a 60% yield from Boc-Leu-Gly-OH and offers a means of achieving the synthesis of hitherto elusive analogues.     

High yield purification of soluble guanylate cyclase from bovine lung

Soluble guanylate cyclase (sGC), the main target of nitric oxide (NO), is a cytosolic, heme-containing, heterodimeric enzyme that catalyzes the conversion of guanosine 5′-triphosphate (GTP) to 3,5′-cyclic guanosine monophosphate (cGMP) and pyrophosphate (PPi) in the presence of Mg²⁺. Cyclic GMP is then involved in transmitting the NO activating signals to a variety of downstream effectors such as cyclic-nucleotide-gated channels, protein kinases, and phosphodiesterases. In this work, sGC has been purified from bovine lung. The lungs were subjected to grinding and extraction with buffer at physiological pH followed by centrifugation. The resulting solution was subjected to successive column chromatography on DEAE- and Q-Sepharose, Ceramic Hydroxyapatite, Resource Q, and GTP–agarose. The purified enzyme migrated as a two-band protein on SDS–PAGE corresponding to sGC subunits α (M_r = 77,532) and β (M_r = 70,500) and had an A_280nm/A_430nm of 1 indicating one heme per heterodimer. The yield of enzyme was 8–10 mg from 4 to 5 kg bovine lungs. V_max and K_m of non-stimulated sGC were 22 nmol/mg/min and 180 μM, respectively. Upon stimulation with the NO donor 3-ethyl-3-(ethylaminoethyl)-1-hydroxy-2-oxo-1-triazene, the V_max increased to 1330 nmol/mg/min while the K_m dropped to 43 μM. The quality and quantity of enzyme make it suitable for studies to probe the structure and catalytic mechanism of this enzyme and for research related to drug discovery.     

High yield production of S-adenosyl-l-homocysteine with microbial cells as the catalyst

A simple and efficient enzymatic process for the production of S-adenosyl-l-homocysteine through catalysis by bacterial S-adenosylhomocysteine hydrolase (EC 3.3.1.1) is described. Washed cells of several actinomycetes, and Alcaligenes and Pseudomonas strains were found to be favorable sources of the enzyme. The reaction is carried out in potassium phosphate, pH 8.0, containing adenosine and l-homocysteine as the substrates, and washed cells of Alcaligenes faecalis AKU 101, which contain a high level of the enzyme, as the catalyst. With concentrations of adenosine and l-homocysteine of up to 200 mM, the molar conversion to S-adenosyl-l-homocysteine after 4–21 h at 37°C was nearly 100%. The maximum yield of 199 mM (76.5 mg ml⁻¹) was attained with a reaction mixture containing 300 mM substrates. S-Adenosyl-l-homocysteine of a high purity was easily isolated from the reaction mixture by simple gel-filtration on Sephadex G-10 with good recovery.