Development of a chemically defined medium for Planctopirus limnophila to increase biomass production     

《Electronic Journal of Biotechnology》2021

BackgroundPlanctomycetes is a phylum of biofilm-forming bacteria with numerous biosynthetic gene clusters, offering a promising source of new bioactive secondary metabolites. However, the current generation of chemically defined media achieves only low biomass yields, hindering research on these species. We therefore developed a chemically defined medium for the model organism Planctopirus limnophila to increase biomass production.ResultsWe found that P. limnophila grows best with a 10 mM sodium phosphate buffer. The replacement of complex nitrogen sources with defined amino acid solutions did not inhibit growth. Screening for vitamin requirements revealed that only cyanocobalamin (B12) is needed for growth. We used response surface methodology to optimize the medium, resulting in concentrations of 10 g/L glucose, 34 mL/L Hutner’s basal salts, 23.18 mM KNO₃, 2.318 mM NH₄Cl and 0.02 mg/L cyanocobalamin. The analysis of amino acid consumption allowed us to develop a customized amino acid solution lacking six of the amino acids present in Aminoplasmal 10%. Fed-batch cultivation in a bioreactor using the optimized medium achieved a final ΔOD₆₀₀ of 46.8 ± 0.5 after 108 h, corresponding to a cell dry weight of 13.6 ± 0.7 g/L.ConclusionsThe optimized chemically defined medium allowed us to produce larger amounts of biomass more quickly than reported in earlier studies. Further research should focus on triggering P. limnophila biofilm formation to activate the gene clusters responsible for secondary metabolism.How to cite: Kruppa OC, Gerlach D, Fan R, et al. Development of a chemically defined medium for Planctopirus limnophila to increase biomass production. Electron J Biotechnol 2021;54. https://doi.org/10.1016/j.ejbt.2021.09.002.  相似文献   

优秀沙排运动员薛晨肩关节脱臼的运动功能康复训练效果分析     

罗晨  张梦雪  薛晨  林万珩 《北京体育大学学报》2017,40(6):60-65

摘要：目的：通过对我国优秀沙滩排球运动员薛晨肩关节脱臼术案例进行分析，探索优秀运动员备战奥运会期间从手术后到重返训练场间的身体运动功能康复训练安排。方法：借鉴重返赛场训练的方法手段，从康复医学、体能训练和运动表现等多学科角度设计有针对性的康复训练方法。通过对比训练前后关节活动度、肌肉力量、功能动作筛查结果以及下肢力量爆发力测试结果检验以优秀沙滩排球运动员肩关节脱臼为个案分析重返赛场的可行性训练策略。结果：通过10周身体运动功能训练，运动员下肢爆发力、损伤侧肩关节内外旋活动度、均有所增加。功能动作筛查分数降低。但损伤侧肩关节内旋肌力、腹侧核心耐力有所下降。结论：以优秀沙滩排球运动员肩关节脱臼重返赛场的训练策略为个案分析，探索从运动损伤术后至重返赛场训练过程的周期安排、训练方法的有效性；通过科学整合康复训练、体能训练和专项技术训练不同训练内容，循序渐进的帮助运动员恢复专项技术和运动能力。  相似文献   

Validation of the Microsoft Kinect® camera system for measurement of lower extremity jump landing and squatting kinematics     

Moataz Eltoukhy  Adam Kelly  Chang-Young Kim  Hyung-Pil Jun  Richard Campbell 《Sports biomechanics / International Society of Biomechanics in Sports》2016,15(1):89-102

Cost effective, quantifiable assessment of lower extremity movement represents potential improvement over standard tools for evaluation of injury risk. Ten healthy participants completed three trials of a drop jump, overhead squat, and single leg squat task. Peak hip and knee kinematics were assessed using an 8 camera BTS Smart 7000DX motion analysis system and the Microsoft Kinect® camera system. The agreement and consistency between both uncorrected and correct Kinect kinematic variables and the BTS camera system were assessed using interclass correlations coefficients. Peak sagittal plane kinematics measured using the Microsoft Kinect® camera system explained a significant amount of variance [Range_hip = 43.5–62.8%; Range_knee = 67.5–89.6%] in peak kinematics measured using the BTS camera system. Across tasks, peak knee flexion angle and peak hip flexion were found to be consistent and in agreement when the Microsoft Kinect® camera system was directly compared to the BTS camera system but these values were improved following application of a corrective factor. The Microsoft Kinect® may not be an appropriate surrogate for traditional motion analysis technology, but it may have potential applications as a real-time feedback tool in pathological or high injury risk populations.  相似文献   

Developing local oral reading fluency cut scores for predicting high‐stakes test performance          下载免费PDF全文

Sally L. Grapin  John H. Kranzler  Nancy Waldron  Diana Joyce‐Beaulieu  James Algina 《Psychology in the schools》2017,54(9):932-946

This study evaluated the classification accuracy of a second grade oral reading fluency curriculum‐based measure (R‐CBM) in predicting third grade state test performance. It also compared the long‐term classification accuracy of local and publisher‐recommended R‐CBM cut scores. Participants were 266 students who were divided into a calibration sample (n = 170) and two cross‐validation samples (n = 46; n = 50), respectively. Using calibration sample data, local fall, winter, and spring R‐CBM cut scores for predicting students’ state test performance were developed using three methods: discriminant analysis (DA), logistic regression (LR), and receiver operating characteristic curve analysis (ROC). The classification accuracy of local and publisher‐recommended cut scores was evaluated across subsamples. Only DA and ROC produced cut scores that maintained adequate sensitivity (≥.70) across cohorts; however, LR and publisher‐recommended scores had higher levels of specificity and overall correct classification. Implications for developing local cut scores are discussed.  相似文献   

高通量药物筛选中靶分子固定化数学物理模型的建立     

李松军  刘白玲 《中国科学院研究生院学报》2005,22(2):179-186

通过对高能量药物筛选基本过程的分析 ,探索了靶分子固定化可能对筛选质量构成的影响 .从分子相互作用看 ,实际的过程远较理想的情况复杂 .分子间存在的静电力、疏水作用力及氢键力能对固定化的机理构成较大影响 ,甚至可能诱发多层吸附的固定化模式 .基于固定化过程中可能存在的靶分子与靶分子、靶分子与微球、体相与表面相之间的相互作用 ,构筑了相应的数学物理模型 ,为实际的筛选工作提供了可参考的理论依据 .  相似文献   

3226例TCT结果分析及其质量控制     

王涛  刘洁  肖波 《荆门职业技术学院学报》2011,(5):36-38

目的：探讨TCT（液基薄层细胞学）与阴道镜下活检的吻合程度,分析不同医生的诊断吻合度,最大限度提高TCT作为宫颈癌筛查手段的的准确性。方法：选取2007年2月至2010年9月期间来我院进行妇科体检TCT异常病例3 226人次的TCT诊断报告与阴道镜活检诊断结果进行比较,以病理活检作为最后诊断。结果：三位主治医生中甲的阅片吻合率为73.98%,乙的吻合率为77.04%,丙的吻合率为82.30%,总的吻合率为78.18%,三者间比较差异极显著（χ2=22.42,P〈0.000 1）。结论：1）TCT细胞学检查与传统的细胞学方法相比取材方便,无创,确诊率高,是宫颈癌筛查的重要方法。2）医生经验在诊断过程中起重要作用,加强对医务人员的培养,适时培训是提高TCT确诊率的重要环节。  相似文献   

MTT法测定八种中草药体外抗肺癌细胞SPC-A1活性     

林董  何爱明  吴祖建 《福建师大福清分校学报》2011,(5):30-33

[目的]建立一套高效、快速的体外中草药抗肺癌活性物质筛选模型。[方法]采用MTT法,对芸香草、地榆、甘草、柴胡、莪术、蜜蒙花、半边莲和旱芹等8种中草药体外抗肺癌细胞SPC-A1的活性进行检测。分析肿瘤细胞生长曲线,观察倒置显微镜下肺癌细胞在不同阶段的生长状况。[结果]在中草药活性物质作用下细胞尽管仍然贴壁,但出现萎缩及边缘清晰化,与生长状况良好的细胞形态区别明显。浓度为1.5mg/ml的莪术乙醇浸提液（ESCC）和甘草乙醇浸提液（ESCG）对体外培养的肺癌细胞SPC-A1有较强的抑制增殖作用,抑制率分别为：52.9%和51.6%,且抑制作用随着浓度的加大而加强。[结论]MTT法筛选可作为8种中草药抗肺癌细胞的一个基本筛选模型。  相似文献   

基于信息贡献率的评价指标筛选与赋权方法     

陈洪海  王慧  隋新 《科研管理》2020,41(8):240-247

针对现有因子分析及相关分析两种方法在指标筛选与赋权方面有待完善之处,提出一种基于信息贡献率的评价指标筛选与赋权方法。该方法首先利用因子方差贡献率和因子载荷构建评价指标的信息贡献率,以此反映该指标解释原始指标集全部信息的比例,然后在现有相关分析法中引入病态指数测度指标集的信息重叠水平,进而实现评价指标的系统筛选与赋权。本研究认为评价指标的信息贡献率越大,其解释原始指标集信息的比例越大,因此该指标越应予以保留,其权重亦应越大。此外,研究亦发现因子分析法易误删信息解释能力强的指标,相关分析法筛选指标易不充分,而本文方法解决了这些问题。  相似文献   

发现新型环境有机污染物的基本理论与方法          下载免费PDF全文

阮挺  江桂斌 《中国科学院院刊》2020,35(11):1328-1336

20世纪以来化学污染物导致的人类健康危害日益突出,数以万计的高生产量化学品伴随着生产和使用进入环境介质,给环境科学相关领域研究提出了若干新的科学问题。文章介绍了发现新型有机污染物研究方向设立的背景和科学意义,讨论了判别新型有机污染物分子结构、环境行为特征的基本原则,阐述了定量结构—性质关系模型预测、疑似目标/非目标分析、效应导向分析方法框架的技术思路和优势。对于新型有机污染物识别、行为和效应的深入探索,将为引领学科方向发展、完善化学品风险评估标准、揭示环境污染物的毒性和健康危害机制发挥重要的支撑作用。  相似文献   

由功能性动作筛查结果看武术套路运动员的体能训练     

陈杰林 《搏击·武术科学》2014,11(10):64-65

对广东省武术套路项目一线运动员进行功能性动作筛查（FMS）,经过对筛查结果进行分析发现,广东省武术套路项目运动员整体FMS筛查结果比较理想（平均得分16.07）,但在躯干稳定俯卧撑以及旋转稳定性测试中得分较低,另外在跨栏架和直线弓步测试中分别有43%和36%的队员出线双侧不均衡的情况,表明核心稳定性不足以及非对称性动作时双侧肢体功能表现不均衡的问题较为突出,需要在专项体能训练中进一步改善和加强。  相似文献