一株产纤维素放线菌SP-2的诱变与筛选

放线菌SP-2是一株具有纤维素降解功能的菌株,通过紫外诱变以及刚果红透明圈法进行筛选,共得到两个酶活较高的突变株SP-2-1、SP-2-2,测定发现其纤维素酶活分别为131.6 U/g和145.2 U/g,比对照分别提高了104.03%和125.12%,并且研究发现两个突变株的纤维素酶活具有良好的遗传稳定性,可作为生产用菌株。     

三种拮抗细菌的发酵培养生长规律研究

通过在不同时间内,对3种拮抗细菌XJ5,XJ7,XJ8进行发酵培养,测定不同发酵培养时间下发酵液吸光值(OD<,600>).结果表明,3株拮抗细菌的生长曲线均呈现"S"曲线.XJ5和XJ8菌株在培养18 h,XJ7在培养12 h时,为3个菌株的快速生长起始时间,吸光值分别为0.413,0.337,0.135.XJ5和XJ8菌株在培养48 h,XJ7则在培养54 h时,为3个菌株的快速生长结束时间,吸光值分别为1.795、2,086和1,807.生长曲线表明了3菌株的最佳培养时间较为一致,在18～48 h之间均可快速生长.     

山西省晋北地区蔬菜灰霉病菌对腐霉利的抗药性检测

从山西省晋北地区朔州和大同两市的蔬菜主要种植区采集分离得到34个灰霉病菌菌株,并就其对腐霉利的抗药性进行了检测.结果表明:34个灰霉病菌菌株对腐霉利的抗性频率为73.53%,其中敏感菌株9株,低抗菌株23株,中抗菌株2株,无高抗菌株和特高抗菌株.     

基于FPLC-LC-MS/MS分析嗜盐古菌Haloarcula hispanica胞内类泛素化底物

本研究结合SLIC克隆技术和快速蛋白质液相色谱-高效液相色谱-串联质谱(FPLC-LC-MS/MS)法,对嗜盐古菌Haloarcula hispanica类泛素蛋白ThiS的泛素化底物和缀合位点进行鉴定分析。采用SLIC克隆法构建类泛素蛋白ThiS表达质粒/整合质粒,经转染后的菌株在DMSO呼吸作用诱导下表达并纯化His6-ThiS蛋白缀合体。通过SDS-聚丙烯酰胺凝胶电泳(SDS-PAGE)分析,质粒型类泛素ThiS的表达远远高于基因型菌株的表达量,而通过定点突变,将ThiS的第89号位点突变成赖氨酸K和精氨酸R,进而使用胰蛋白酶对ThiS肽段上的赖氨酸残基-双甘氨肽标签进行酶切处理,采用LC-MS/MS法鉴定其底物和底物修饰位点。鉴定得到钼喋呤合成酶MoaE,蛋氨酸亚砜还原酶MsrA和其同系物MsrB,以及Fe-S簇组装蛋白SufB等4种底物蛋白。该方法通过结合蛋白位点突变和质谱检测,能够准确、有效地检测泛素/类泛素蛋白的修饰底物及其修饰位点,为深入泛素的生物性功能研究提供了切入点。     

山西省晋北地区蔬菜灰霉病菌对乙霉威的抗药性检测

通过对山西省晋北地区蔬菜主要种植区灰霉病菌对乙霉威的抗药性检测,结果表明:32个灰霉病菌菌株时乙霉威的总体抗性频率为68.75%,其中有10株敏感菌株、4株低抗菌株、1株中抗菌株、10株高抗菌株、7株特高抗菌株.     

一株番茄灰霉病菌拮抗菌的系统鉴定

Y-21是从山东省淄博市蔬菜温室中分离到的一株细菌,通过室内平板对峙试验,对番茄灰霉病菌具有较强的拮抗性。本研究通过形态观察、生理生化反应和分子生物学方法对这株细菌进行系统鉴定。显微镜观察菌株形态为杆状;有芽孢;革兰氏染色呈阳性。采用经典的基因组提取方法提取基因组DNA,以其为模板,利用引物63F、1494R扩增16SrRNA基因,回收16SrRNA基因的PCR产物并与T载体连接,通过热激法将重组质粒转人大肠杆菌感受态细胞,利用蓝白斑筛选,挑出白斑,提取质粒,通过蓝白斑质粒的电泳图比对和质粒的PCR检测确定阳性克隆,将阳性克隆菌株送样测序。将测序结果输入BLAST进行比对,发现Y-21属于假单胞菌属,然后对其构建系统发育树。     

一株番茄灰霉病菌拮抗菌的系统鉴定

Y-21是从山东省淄博市蔬菜温室中分离到的一株细菌,通过室内平板对峙试验,对番茄灰霉病菌具有较强的拮抗性。本研究通过形态观察、生理生化反应和分子生物学方法对这株细菌进行系统鉴定。显微镜观察菌株形态为杆状;有芽孢;革兰氏染色呈阳性。采用经典的基因组提取方法提取基因组DNA,以其为模板,利用引物63F、1494R扩增16S rRNA基因,回收16SrRNA基因的PCR产物并与T载体连接,通过热激法将重组质粒转入大肠杆菌感受态细胞,利用蓝白斑筛选,挑出白斑,提取质粒,通过蓝白斑质粒的电泳图比对和质粒的PCR检测确定阳性克隆,将阳性克隆菌株送样测序。将测序结果输入BLAST进行比对,发现Y-21属于假单胞菌属,然后对其构建系统发育树。     

北戴河水产养殖海域可培养微生物多样性及耐药性分析

为了解北戴河水产养殖海域微生物多样性及可培养微生物的耐药性，应用高通量测序对海水和底泥进行多样性分析，并对可培养微生物进行鉴定及耐药性筛选。结果表明，此海域菌种资源丰富，包括变形菌门（Proteobacteria）、厚壁菌门（Firmicutes）和拟杆菌门（Bacteroidota）等。共分离72株菌株，其中海水44株，底泥28株，优势菌属分别为变形菌门和厚壁菌门。其中有4株对四环素类和磺胺类中的4种抗生素耐药，对喹诺酮类中的两种抗生素敏感，表现出多重耐药性。     

诺卡氏菌型放线菌中甲基萘醌的高效液相色谱研究

本文以已知的星状诺卡氏菌(Nocardia asteroides)、紫红红球菌(Rhodococcusrhodochrous)和灰色链霉菌(Streptomyces griseus)标准菌株中提取的醌作为对照样品,用高效液相色谱法,分析测定9株诺卡氏菌型放线菌的甲基萘醌。结果表明,该法是一种较理想的甲基蔡醌测定方法,可应用于诺卡氏菌型放线菌的分类和鉴定。     

修文县猕猴桃根际微生物区系及病原拮抗菌筛选

为研究猕猴桃根际土壤中细菌、真菌和放线菌区系及其与土壤养分的关系,分离筛选对灰霉菌有较好防效的生防菌。采用稀释平板法及皿内琼脂块法对采自修文县猕猴桃根际土壤微生物进行分离测数及拮抗菌筛选。结果表明修文县猕猴桃根际土壤中细菌的平均数量为11.13×107 cfu/g干土,真菌为97.63×102 cfu/g干土,放线菌为12.06×104 cfu/g干土。相关性分析结果表明土壤养分对根际土壤微生物区系形成有较大影响;在分离到的菌株中,有1株真菌和1株放线菌对灰葡萄孢有拮抗性。初步鉴定为黑曲霉属和链霉菌属。     

Effects of aging and HIF-1alpha deficiency on permeability of hippocampal vessels

We examined age-related changes in the blood-brain barrier (BBB) of neural cell-specific hypoxia inducible factor-1alpha (HIF-1alpha) deficient mice, which showed hydrocephalus with neuronal cell loss, to investigate an effect of neural cell-specific HIF-1alpha deficiency or hydrocephalus on vascular function. Vascular permeability of horseradish peroxidase (HRP) and binding of cationized ferritin (CF) particles to the endothelial cell luminal surface, as a marker of glycocalyx, were investigated. The thickness of CF-labeled glycocalyx was significantly decreased in the cortex in mutant mice compared with that of control mice, although it was not paralleled by increased vascular permeability. In addition, strong staining for HRP was seen around vessels located along the hippocampal fissure in 24-month-old mutant mice. The reaction product of HRP appeared in an increasing number of the endothelial cell abluminal vesicles and within the thickened basal lamina of arterioles in the hippocampus, showing increased vascular permeability. There were no leaky vessels in 10-week-old mutant mice or 10-week-old and 24-month-old control mice. These findings suggest the necessity of two factors, aging and hydrocephalus, for BBB dysfunction in HIF-1alpha deficient mice.     

Mapping protein expression in mouse pancreatic islets by immunolabeling and electron energy loss spectrum-imaging

A combination of immuno-electron microscopy and electron energy-loss spectrum-imaging was used to map the distributions of endocrine polypeptide hormones and proteins in mouse pancreatic islet of Langerhans. Tissue was analyzed from control animals and from mice that were heterozygous for the Anx7 gene, which defines a Ca2+/GTP-dependent membrane fusion and ion channel protein. The heterozygous Anx7 (+/-) mouse displays defects in IP3 receptor mediated Ca2+ signaling and insulin secretion. Therefore, information was obtained about the distributions of the hormones insulin and glucagon, as well as the proteins ANX7 and the IP3 receptor. Insulin secretion appears to be defective in the mutants. It was found from immunolabeling experiments that expression of the IP3 receptor is reduced in mutant islets compared to control islets. Subcellular distributions of sulfur and nitrogen obtained by electron energy-loss spectrum-imaging showed that the insulin concentrations of beta granules were essentially the same in control and mutant islets. By contrast, immunogold labeling of mutant islets shows more insulin immunoreactivity in the beta granules. It follows that insulin may be packaged differently in mutant islets, making antigenic determinants more available to the labeling antibody. The increased rate of insulin secretion in the hyperplastic mutant islets can be explained by compensatory increases in islet size, rather than by an increased insulin concentration in the beta cells. The results indicate that reduced ANX7 expression leads to defects in the IP3 receptor expression in the endocrine cells of the mutant mouse. Increased size of the islet or of adrenal medulla may be a compensatory mechanism for secretion defect by individual endocrine cells. Defects in IP3 receptor expression, and documented consequences of a Ca2+ signaling defect, lead to other changes in organelles such as the mitochondrial number in islet beta-cells. The effects and consequences of reduced ANX7 expression on mitochondria are evident in ultrastructural observations.     

Advanced technique for achieving 10-μm-width fine lines in roll-to-roll continuous gravure printing

In roll-to-roll continuous printing, given the limitations in the pattern engraving technique and the need for accurate contact angle control between the ink and substrate, printing fine lines in the 10-μm scale is a major hurdle that needs to be addressed to achieve mass production of printed electronic devices. To address this issue, we propose a novel printing method based on gradation engraving; this method allows for both greater control over the width decrement of printed patterns as well as narrower fine lines than those achieved using an engraved pattern in the printing roll. Our experimental results show that, using the proposed method, printed line widths could be decreased according to the curvature of the sidewall of the engraved cell, even in the same aspect ratio. Furthermore, the width of the printed pattern was decreased by up to 62%, as compared to that achieved via the engraved cell, and a fine printed line narrower than 10-μm could be achieved. The proposed method represents a suitable alternative for the fabrication of 10-μm, or even thinner, fine conductive lines via the roll-to-roll continuous printing process.     

基于普通换向阀的高精度油缸位置控制

针对基于普通换向阀的位置控制系统,由于控制时滞,普遍存在控制精度不高,系统抖振的问题,提出了一种开关线迭代学习的改进型Bang-Bang控制方案。开关特性和相平面理论分析表明,换向阀的控制输出时滞是影响控制精度和引起系统抖振的主要原因。推导了液压系统的油缸速度、阀芯位移、负载压力的数学方程式。新开发了一种基于开关线迭代学习的改进型Bang-Bang控制算法,并通过仿真和生产验证了控制算法的正确性和可靠性。实际生产过程中,辊缝控制精度小于等于0.1 mm的命中率为89.3%,全部控制精度小于0.2 mm。整个系统控制稳定,控制精度较高,满足生产工艺要求。     

一种多周期随机需求生产/库存模型

为使存贮、生产和缺货等费用的总和最小，建立了一种多周期随机需求生产／库存模型，该模型采用（S，Q）策略对生产和库存进行控制，即当成品库存降至8时准备生产，生产量为Q。通过对该模型费用函数特性的分析，设计了一种迭代学习算法，根据该算法可以得出系统的最优生产准备点及最优生产量。将所提出的迭代学习算法与遗传算法进行了比较，结果显示，两者所得到的控制量是吻合的，且迭代学习算法的求解速度更快，从而证实所建立的模型和提出的迭代学习算法是正确有效的。     

计算机辅助工艺过程设计系统THCAPP-1的建造

本文提出了一个利用人工智能专家系统技术来建造CAPP系统的创新方案,并开发了一个以加工中心为背景的计算机辅助工艺规程设计系统,名为清华CAPP系统(THCAPP-1)。系统采用类似英语谓词来描述零件,以生成式规则来表达工艺领域知识,并且提出了层次规化的概念和过程网结构,利用由过程网和谓词构成中间数据库来贮存中间层次规划。系统采用由后向前,逐层深入的推理方法作为控制结构。并在北京第一机床厂进行验证,获得成功。     

基于陀螺仪与伺服舵机的自动安平系统设计

针对目前传统的安平系统在实用性和适用性未能满足多方面要求,无法解决同时兼顾安平范围、调节精度和响应速度的问题,根据三轴陀螺仪传感器与伺服舵机控制原理,设计了一种新型的自动安平系统,通过三轴陀螺仪传感器检测重力加速度方向以获取倾角信息,由STM32F103系列微控制器对采集获取的数据进行了数字滤波和分析计算等处理,并结合PWM脉宽调制技术和PID算法控制伺服舵机机组,实现了双自由度的水平调节,并且对系统的机械结构进行了优化设计,有效增大了安平范围.研究结果表明,该自动安平系统在-90°～＋90°范围内的调节精度达到10′33″,水平度误差控制在0.1％～0.5％范围之内,调整时间小于2s,相对于其他安平系统,具有更低的生产成本和更高的自动化程度.     

Light and low-frequency pulsatile hydrostatic pressure enhances extracellular matrix formation by bone marrow mesenchymal cells: an in-vitro study with special reference to cartilage repair

Ovine bone marrow mesenchymal cells (BMMCs) were seeded on to non-woven filamentous plasma-treated polyester scaffolds and cultured in a chondrogenic medium for 4 weeks. Thereafter a pulsatile hydrostatic pressure (PHP) was applied to these cell-scaffolds constructs at an amplitude of 0.1 MPa and frequency of 0.25 Hz, for 30 min a day, over a period of 10 days. Samples (n = 6) were removed 24 h after PHP stimulation at days 1, 4, 7, and 10 for biochemical analysis. Similar analyses were conducted, at the same time points, on control samples that were not subjected to a PHP. The results showed that the glycosaminoglycan (GAG) content did not significantly increase until after the application of a PHP for 7 days. The GAG content was 1.5 and 2.7 times higher in the PHP group than in the control group at days 7 and 10 respectively (p<0.01). The deoxyribonucleic acid (DNA) content was 1.5 times greater in the PHP group than in the control group at day 10 (p<0.01). GAG synthesis amounts, expressed as the total GAG contents per microgram of DNA, were 1.6 and 1.8 times higher in the PHP group than in the control group at days 7 and 10 respectively (p<0.01). The total collagen content in the medium did not change until after PHP application for 10 days, when it was 1.9 times higher than the control (p < 0.05). The results suggest that a light PHP applied at a low frequency has a cumulative stimulatory effect on the BMMCs' metabolic activities including cell proliferation and synthesis of the extracellular matrix.     

云制造环境下基于离散Markov跳变系统的机床装备资源动态优选方法

针对云制造环境下加工任务执行过程中机床装备资源易受紧急插单、加工质量异常、设备运行故障等高频随机扰动影响,致使产品加工服务质量(QoS)不能满足客户个性化需求的问题,提出一种基于离散Markov跳变系统的机床装备资源动态优化选择方法.首先,结合云制造服务运行特点,构建了云制造环境下面向加工任务执行过程的服务质量动态演化...     

基于LabVIEW的模糊控制系统设计

图形编程语言LabVIEW和模糊控制系统凭借其各自的特点在工业生产中得到广泛的应用,但是将两者结合的应用比较少。结合LabVIEW和模糊控制系统的优点,分析了LabVIEW中实现模糊控制系统的方法,利用PID and FuzzyLogic Toolkit设计了一个基于LabVIEW的模糊控制器,并对频率为10.1 Hz,幅值为1的正弦波和三角波信号进行跟踪。结果表明:基于LabVIEW的模糊控制器结合了两者的优点,易于实现并具有良好的动态特性。