Influencer-defaulter mutation-based optimization algorithms for predicting electricity prices

Efficient electricity price forecasting plays a significant role in our society. In this paper, a novel influencer-defaulter mutation (IDM) mutation operator has been proposed. The IDM operator has been combined with six well-known optimization algorithms to create mutated optimization algorithms whose performance has been tested on twenty-four standard benchmark functions. Further, the artificial neural network is integrated with mutated optimization algorithms to solve the electricity price prediction problem. The policymakers can identify appropriate variables based on the predicted prices to help future market planning. The statistical results prove the efficacy of the IDM operator on the recent optimization algorithms.     

盖子环替换及定点突变提高菜豆环氧化物水解酶对邻甲基苯基缩水甘油醚的催化性能

菜豆环氧化物水解酶1和2（PvEH1、PvEH2）能够动力学拆分外消旋邻甲基苯基缩水甘油醚（rac-oMGE），从而保留(R)-oMGE。基于对PvEH1和PvEH2结构的同源模拟和分析，发现二者分子中的盖子环差异较大，故本文选择盖子环作为研究目标。经融合聚合酶链式反应（FPCR），获得了PvEH2的盖子环区域被PvEH1对应区域替换的杂合酶Pv2Pv1。用全细胞酶E. coli/pv2pv1催化rac-oMGE，当(S)-oMGE刚好水解完全时，产物(S)-3-邻甲苯基-1,2-丙二醇（(S)-oTPD）的ee_p由PvEH2的58.3%提高至75.5%。为进一步提高酶的性质，在Pv2Pv1中选取11个氨基酸位点进行丙氨酸(A)突变，获得最优突变子E. coli/pv2pv1^K176A，活性为E. coli/pv2pv1（4.2U/g）的2.1倍，且当S构型的底物刚好完全水解时，(S)-oTPD的ee_p进一步提高为80.3%。分子对接分析发现，盖子环替换和K176位点突变为A，均使(R)-oMGE环氧环中的C_α更易受到酶中D101位点的攻击。利用E. coli/pv2pv1^K176A催化150mmol/L rac-oMGE水解制备(R)-oMGE（ee_s＞99%）和(S)-oTPD（ee_p=80.4%），二者的产率Y_S和Y_P分别为32.7%和60.1%，时空产率STY_S和STY_P为1.6g/(L·h)和3.3g/(L·h)。本实验为改善EH的催化性质提供了一种有效策略。     

基于变异算子和邻域值自适应的MOEA/D算法

基于分解的多目标进化算法（MOEA/D）在解决多目标问题时，具有简单有效的特点。但多数MOEA/D采用固定的控制参数，导致全局搜索能力差，难以平衡收敛性和多样性。针对以上问题提出一种基于变异算子和邻域值自适应的多目标优化算法。该算法根据种群中个体适应度值的分散或集中程度进行判断，并据此对变异算子进行自适应的调节，从而增强算法的全局搜索能力；根据进化所处的阶段以及个体适应度值的集中程度，自适应地调节邻域值大小，保证每个个体在不同的进化代数都有一个邻域值大小；在子问题邻域中，统计子问题对应个体的被支配数，通过判断被支配数是否超过设定的上限，来决定是否将Pareto支配关系也作为邻域内判断个体好坏的准则之一。将提出的算法与传统的MOEA/D在标准测试问题上进行对比。实验结果表明，提出的算法求得的解集具有更好的收敛性和多样性，在求解性能上具有一定的优势。     

Stationary and Progressive Phenotypes Caused by the p.G90D Mutation in Rhodopsin Gene

Mutations in rhodopsin gene (RHO) are a frequent cause of retinitis pigmentosa (RP) and less often, congenital stationary night blindness (CSNB). Mutation p.G90D has previously been associated with CSNB based on the examination of one family. This study screened 60 patients. Out of these 60 patients, 32 were affected and a full characterization was conducted in 15 patients. We described the clinical characteristics of these 15 patients (12 male, median age 42 years, range 8–71) from three families including visual field (Campus Goldmann), fundus autofluorescence (FAF), optical coherence tomography (OCT) and electrophysiology. Phenotypes were classified into four categories: CSNB (N = 3, 20%) sector RP (N = 3, 20%), pericentral RP (N = 1, 6.7%) and classic RP (N = 8, 53.3% (8/15)). The phenotypes were not associated with family, sex or age (Kruskal–Wallis, p > 0.05), however, cystoid macular edema (CME) was observed only in one family. Among the subjects reporting nyctalopia, 69% (22/32) were male. The clinical characteristics of the largest p.G90D cohort so far showed a large frequency of progressive retinal degeneration with 53.3% developing RP, contrary to the previous report.     

An improved cuckoo search algorithm and its application in vibration fault diagnosis for a hydroelectric generating unit

This article presents an improved cuckoo search (ICS) algorithm based on the parametric adaptation mechanism and non-uniform mutation. In the ICS algorithm, the biased random walk operator is modified to take advantage of the neighbourhood information of the current solution, and then the control parameters of step size, discovery probability and scaling factor are directly integrated into the optimized problems. Meanwhile, the non-uniform mutation operation is used to adaptively tune the search step of the current optimal solution. To evaluate the feasibility and efficiency of the presented algorithm, three groups of benchmark test functions are employed to perform the validation analysis. Subsequently, to diagnose the vibration fault of a hydroelectric generating unit, a combinational model is built, which combines ICS with a back-propagation neural network (ICSBP). The experimental results indicate that ICS is competitive on the optimization problems, and the ICSBP approach can effectively improve the accuracy of vibration fault diagnosis for a hydroelectric generating unit.     

碳源对manA基因突变大肠杆菌代谢的影响

ManA基因编码的甘露糖-6-磷酸异构酶在大肠杆菌中催化D-甘露糖和D-果糖的异构化,促进大肠杆菌对碳源的代谢吸收。本文通过研究manA基因突变大肠杆菌对碳源的利用和编码糖代谢基因情况,探讨甘露糖-6-磷酸异构酶对大肠杆菌糖代谢的影响。采用Ⅱ型内含子逆转录突变方法构建manA基因突变大肠杆菌,分析manA基因突变大肠杆菌对不同碳源的利用情况和manA基因突变对大肠杆菌糖代谢相关基因表达的影响,结果显示,大肠杆菌BL21(DE3)ΔmanA以甘露糖、果糖为碳源时,菌株生长受到显著抑制;以淀粉为碳源时,BL21(DE3)ΔmanA菌株的生长显著优于野生型大肠杆菌;以葡萄糖为碳源时,manA基因突变对大肠杆菌的生长无显著影响。通过基因表达分析,发现大肠杆菌BL21(DE3)ΔmanA中甘露糖代谢相关基因的表达显著性降低;果糖代谢途径中6-磷酸果糖激酶Ⅰ亚基的编码基因(pfkA)显著下调表达;水解淀粉的α-淀粉酶编码基因(malS)显著性上调表达。ManA基因突变影响大肠杆菌甘露糖、果糖和淀粉代谢途径中相关基因的表达,从而影响大肠杆菌对碳源的利用。     

New Insights into the Pathogenesis of Systemic Mastocytosis

Mastocytosis is a type of myeloid neoplasm characterized by the clonal, neoplastic proliferation of morphologically and immunophenotypically abnormal mast cells that infiltrate one or more organ systems. Systemic mastocytosis (SM) is a more aggressive variant of mastocytosis with extracutaneous involvement, which might be associated with multi-organ dysfunction or failure and shortened survival. Over 80% of patients with SM carry the KIT D816V mutation. However, the KIT D816V mutation serves as a weak oncogene and appears to be a late event in the pathogenesis of mastocytosis. The management of SM is highly individualized and was largely palliative for patients without a targeted form of therapy in past decades. Targeted therapy with midostaurin, a multiple kinase inhibitor that inhibits KIT, has demonstrated efficacy in patients with advanced SM. This led to the recent approval of midostaurin by the United States Food and Drug Administration and European Medicines Agency. However, the overall survival of patients treated with midostaurin remains unsatisfactory. The identification of genetic and epigenetic alterations and understanding their interactions and the molecular mechanisms involved in mastocytosis is necessary to develop rationally targeted therapeutic strategies. This review briefly summarizes recent developments in the understanding of SM pathogenesis and potential treatment strategies for patients with SM.     

Some Molecular and Cellular Stress Mechanisms Associated with Neurodegenerative Diseases and Atherosclerosis

Chronic stress is a combination of nonspecific adaptive reactions of the body to the influence of various adverse stress factors which disrupt its homeostasis, and it is also a corresponding state of the organism’s nervous system (or the body in general). We hypothesized that chronic stress may be one of the causes occurence of several molecular and cellular types of stress. We analyzed literary sources and considered most of these types of stress in our review article. We examined genes and mutations of nuclear and mitochondrial genomes and also molecular variants which lead to various types of stress. The end result of chronic stress can be metabolic disturbance in humans and animals, leading to accumulation of reactive oxygen species (ROS), oxidative stress, energy deficiency in cells (due to a decrease in ATP synthesis) and mitochondrial dysfunction. These changes can last for the lifetime and lead to severe pathologies, including neurodegenerative diseases and atherosclerosis. The analysis of literature allowed us to conclude that under the influence of chronic stress, metabolism in the human body can be disrupted, mutations of the mitochondrial and nuclear genome and dysfunction of cells and their compartments can occur. As a result of these processes, oxidative, genotoxic, and cellular stress can occur. Therefore, chronic stress can be one of the causes forthe occurrence and development of neurodegenerative diseases and atherosclerosis. In particular, chronic stress can play a large role in the occurrence and development of oxidative, genotoxic, and cellular types of stress.     

常压室温等离子体(ARTP)诱变选育高核酸酿酒酵母

核糖核酸(RNA)是一类非常重要的生物分子,降解后得到的核苷酸、核苷及碱基具有广泛用途。酿酒酵母是目前生产RNA的主要食品级微生物。本研究采用常压室温等离子体(ARTP)技术进行酿酒酵母诱变育种,利用氯化钾敏感性筛选,多次反复诱变最终得到在以糖蜜为碳源的摇瓶试验中RNA含量为112 mg-RNA/g-DCW,提高了39%的突变菌株Y17aM3。经过对Y17aM3培养条件优化后,确定生产RNA最适接种量为10%,最适p H为5.5,最适温度为26℃,且传代稳定性良好。研究发现在最佳培养条件下,添加磷酸可使Y17aM3的RNA含量提高至119 mg-RNA/g-DCW;添加蛋白胨可使Y17aM3的RNA含量提高至122 mg-RNA/g-DCW。上述结果不仅证明ARTP诱变育种方法突变效果显著,可应用于工业微生物的选育,而且有助于降低基于核苷酸的食品添加剂的生产成本。     

基于计算机模拟技术优化筛选核酸适配体的初探

目的:通过分子模拟技术优化筛选5’单磷酸腺苷(AMP)的高特异性适配体,利用胶体金可视化试验验证筛选结果。方法:研究文献中已知的AMP原始适配体(S0)的结合位点,对7个关键碱基进行多轮迭代单点突变,获得新的适配体,进一步比较结合自由能,优化获得特异性高的适配体序列。结果:历经5轮筛选,优化筛选出4个特异性高的新序列(S1-S4),使用胶体金的可视化检测对最佳新序列(S4)和原始序列(S0)作比较,结果发现试验结果与模拟结果一致性良好。结论:计算机模拟技术优化筛选适配体具有省时、易制备、分子质量小、储存运输简单等多种优势,为快速获得特异性适配体提供了一个新方法、新思路。