circRNAs在植物中的研究进展

circular RNA(circRNA)是一类具有闭合环状结构的内源性非编码RNA,广泛存在于多种真核生物中,具有结构稳定、序列保守、表达特异性等特征。研究表明circRNAs可作为海绵(sponge)吸附microRNA(miRNA)并参与其表达调控过程,也可通过与蛋白互作调控基因表达等生物过程;发现circRNAs不仅参与植物激素信号转导等生理过程,而且还能在植物响应逆境胁迫中起到重要作用。该文主要对近年来国内外有关circRNAs的类型、形成机制、功能及其在植物生长发育过程中的研究进展进行了综述,并讨论了circRNAs的研究意义及存在的问题,为进一步研究circRNAs在植物中的作用机制及其基因调控网络提供参考。     

Review on antibacterial biocomposites of structural laminated veneer lumber

In this review, the characteristics and applications of structural laminated veneer lumber made from planted forest wood is introduced, and its preparation is explained, including various tree species and slab qualities, treatments for multiple effects and reinforced composites. The relevant factors in the bonding technology and pressing processes as well as the mechanical properties, research direction and application prospects of structural laminated veneer lumber made from planted forest wood are discussed.     

Calculation of immobilized enzyme reaction progress curves from nested ordered-sequential rate expressions

A method for estimating immobilized enzyme reaction progress curves, using simultaneous non-linear regression analysis of 2–3 substrate concentrations with time, is presented. These facile procedures involve using nested Gauss–Newton curve fitting algorithms on a Microsoft EXCEL spreadsheet. We refer to our technique as "nested" because the analysis consists of two or three mutually parameter-dependent sets of computations associated with bi- or termolecular enzyme-catalyzed reactions, respectively. We have applied the method to immobilized glucose oxidase-catalyzed reactions ([ -glucose] and [O₂] with time) and found that the kinetic parameters from initial velocity data were similar to those determined by the nested curve fitting method discussed herein.     

The effect of weekend curfews on epidemics: a Monte Carlo simulation

The ongoing COVID-19 pandemic is being responded with various methods, applying vaccines, experimental treatment options, total lockdowns or partial curfews. Weekend curfews are among the methods for reducing the number of infected persons, and this method is practically applied in some countries such as Turkey. In this study, the effect of weekend curfews on reducing the spread of a contagious disease, such as COVID-19, is modeled using a Monte Carlo algorithm with a hybrid lattice model. In the simulation setup, a fictional country with three towns and 26,610 citizens were used as a model. Results indicate that applying a weekend curfew reduces the ratio of ill cases from 0.23 to 0.15. The results also show that applying personal precautions such as social distancing is important for reducing the number of cases and deaths. If the probability of disease spread can be reduced to 0.1, in that case, the death ratio can be minimized down to 0.     

Yield,Yield‐related Traits and Response of Potato Clones to Late Blight Disease,in North‐Western Highlands of Ethiopia

Late blight disease of potato caused by Phytophthora infestans poses a significant threat to potato production in Ethiopia. The development of new high yielding genotypes with adequate late blight disease resistance will provide a strong component of an integrated management strategy for farmers. The objective of this study was to determine late blight resistance and yield of potato clones under field condition in north‐western Ethiopia. Twenty‐four clones (17 from the International Potato Centre B3C2 population and seven widely grown cultivars) were evaluated at three locations. The experiment was laid in a randomized complete block design with two replications. Late blight resistance and yield‐related traits were determined. Results showed that clones differ significantly for all traits across locations. The following five clones combine high to moderate resistance to late blight with high yields: 396029.250, 395017.229, 396004.263, 396034.103 and 395077.12. These clones are useful genetic resources for resistance breeding against late blight disease and for enhanced yields.     

植物CRISPR基因组编辑技术的新进展

在过去的4年中,CRISPR/Cas9基因组编辑技术成为生命科学领域的革命性工具,为植物学基础研究和农作物遗传改良提供了高效、快速而又廉价的遗传操作工具。利用CRISPR/Cas9系统可以实现精准的knock-out和knock-in等遗传操作,也可用于靶向激活或抑制基因的表达。在CRISPR/Cas9被广泛地用于基因组编辑的同时,它的编辑能力、效率和精确度也在不断地改进和完善,特别是CRISPR/Cpf1系统的发掘和单碱基编辑技术的创建,使CRISPR系统正逐步成为一个理想的遗传工程技术平台。此外,利用CRISPR/Cas9技术改良的农作物品种也已经涌现,这必将推动精准基因组编辑技术在农作物遗传改良中的应用和发展。     

钾离子通道与神经胶质瘤关系的研究进展

钾离子通道为组织细胞内分布最广、种类最多的离子通道,在细胞增殖、分化及肿瘤细胞的侵袭转移中起着关键作用。神经胶质瘤是颅内最多发的恶性肿瘤,目前其主要治疗方式为手术加术后放化疗,术后五年生存率较低,寻找其相关发病机制及化疗靶点具有重要意义。目前已有多项研究表明,多种钾离子通道在胶质瘤中呈特异性高表达,且与胶质瘤的增殖、分化有密切关系,一些钾离子通道可作为胶质瘤的诊断和预防因子,有望成为未来胶质瘤化疗的新靶点,研究钾离子通道与神经胶质瘤的关系对胶质瘤的诊断、预防和治疗有重要意义。本文主要对近年来钾离子通道与神经胶质瘤关系研究的新进展进行综述。     

口服降糖药和胰岛素对不同临床分期糖尿病视网膜病变病情进程的影响

目的:探讨降糖药物和胰岛素控制血糖对不同临床分期糖尿病视网膜病变进程的影响。方法:收集糖尿病伴有视网膜病变的患者78例。采用随机表法,将糖尿病视网膜病变患者分为药物控制血糖组和胰岛素控制组,药物治疗组38例,胰岛素治疗组40例,使血糖达到控制标准。评价干预前后患者血清C肽、糖化血红蛋白、胰岛素抵抗指数,以及糖尿病视网膜病变分级。结果:药物控制组治疗前后2 h CP、以及糖化血红蛋白测定差异无统计学意义(p0.05)。胰岛素组治疗前后,血清空腹C肽、2 h CP差异有统计学意义(p0.05);而糖化血红蛋白、胰岛素抵抗指数差异无统计学意义(p0.05)。药物组治疗前Ⅰ期、Ⅱ期、Ⅲ期、Ⅳ期、Ⅴ期、Ⅵ期病例数和治疗后相比,差异有统计学意义(p0.05),视网膜病变分级程度明显增高。胰岛素组治疗前Ⅰ期、Ⅱ期、Ⅲ期、Ⅳ期、Ⅴ期、Ⅵ期病例数和治疗后相比,差异有统计学意义(p0.05)。药物组和胰岛素组间视网膜病变分级差异无统计学意义(p0.05);治疗后差异有统计学意义(p0.05)。结论:胰岛素能够提高糖尿病患者血清C肽,降低胰岛素抵抗,和药物控制血糖相比,能够延缓糖尿病视网膜病变的进展。     

阿尔茨海默病的发病机制及药物治疗的研究进展

阿尔茨海默病(Alzheimer's disease,AD)是一种慢性进行性神经变性疾病,早期临床表现为近期记忆力下降,后来逐渐发展为生活不能自理最终死亡。目前,有许多种假说阐述其发病机制,如β-淀粉样蛋白、载脂蛋白E、一些金属元素、炎症因子等,但都不全面,也有人认为其可能与朊蛋白有关。部分药物被用于治疗AD,如美金刚、胆碱酯酶抑制剂等,但疗效均不显著。一些新的治疗理念和方法也逐渐被发现,如脑源性神经生长因子(brain-derived neurotrophic factor,BDNF)以及免疫疗法等,但其远期疗效还需进一步证实,且一些副作用还并未被人们所知晓。本文主要对阿尔茨海默病的发病机制及药物治疗的研究进展进行了综述。     

韭菜迟眼蕈蚊发生规律及防治方法研究进展

韭菜迟眼蕈蚊是我国韭菜生产中的重要害虫,各韭菜种植区均有发生。随着北方设施农业的迅速发展,良好的温室环境使韭菜迟眼蕈蚊的为害愈加严重,已成为制约韭菜种植业发展的重要因素。上世纪80年代,分类学家正式确定韭菜迟眼蕈蚊Bradysia odoriphaga是我国韭菜根蛆类害虫的优势物种,此后,在生物学、生理学、生态学等基础研究领域和防治方法等应用研究领域,有关韭菜迟眼蕈蚊的研究都取得了很大进展。本文全面总结了韭菜迟眼蕈蚊在我国各韭菜种植区及不同种植模式下的发生规律,详细叙述了农业、物理、生物、化学等相关防治措施,综合介绍了韭菜迟眼蕈蚊防治方法近二十年内的研究成果,对未来韭菜迟眼蕈蚊的综合治理方向进行了展望。