类器官的研究进展及应用前景

类器官（organoids）来源于自组织和自我更新的干细胞，是利用干细胞的自组织特性进行体外3D培养后形成的细胞团，与来源器官密切相关，再现了来源器官的三维细胞结构，并为探索来源器官的发病机制提供了新的模型。类器官系统是由自分泌、旁分泌或邻分泌信号调节下的细胞，或者外源性添加的细胞外基质（extracellular matrix，ECM）底物、小分子和生长因子等衍生而来，这些因素的相互作用创造了一个动态的环境，指导干细胞的自我更新和分化，以及细胞在类器官中的自我组装。诱导多能干细胞（induced pluripotent stem cells，iPSC）重编程方法结合3D类器官工具，使患者来源的类器官作为动物模型和人类临床试验之间的桥梁，是对细胞研究和在体试验的补充。在研究来源器官发育、生物学和病理生理学方面，类器官不仅是一种比传统细胞培养更具生理相关性的体外模型，而且还是再生医学和个性化医学领域中的新模型，有望成为研究营养素、药物、毒物及毒素等的作用机制及药物的筛选、再生医学等领域的重要模型。总之，类器官技术的发展增强了人们对器官和组织生理生化功能的认知。作者对肠、脑、肺脏、肝脏、子宫、卵巢等类器官培养和应用的研究进展进行综述，以期为类器官相关科研及应用提供参考。     

处理主干和主枝对光皮树幼树早花早实的促进效果

对3年生光皮树幼树,采用环割倒贴皮、铁丝绞缢、绳索绞缢、环刻4种人工造伤方法分别对其主干和主枝进行处理.结果表明:4种处理方法对树干直径和冠幅生长的影响差异不显著;铁丝绞缢主枝法处理,其树高及开花株数和开花数量都与其他处理存在显著差异;铁丝绞缢主枝与铁丝绞缢主干法促进开花的效果差异不显著.     

基于氮梯度加载下的温室核桃砧木苗生长生理特性变化

【目的】探究新疆核桃砧木苗生长特征及生理特性对氮梯度的响应,为核桃砧木苗施氮标准化的探究奠定基础。【方法】以阿克苏厚皮农家种质核桃砧木苗为研究对象,进行不同梯度的氮素诱导,测定核桃砧木苗生长及生理指标。【结果】基于氮梯度加载下的核桃砧木苗株高、地径、叶片数、叶长、光合色素含量、可溶性蛋白质含量、可溶性糖含量、硝酸还原酶活性、谷氨酰胺合成酶活性均呈上升趋势,并在15 g.a^-1.m^-2处理下达到最高值。【结论】适量地增施氮肥有利于核桃砧木苗的生长、提高砧木苗体内营养物质含量以及促进氮代谢能力。     

我国玉米茎腐病研究进展

玉米茎腐病是一种世界性土传真菌病害，该病害在我国玉米产区均有发生。近年来，受耕作制度（如保护性耕作、秸秆还田等）的改变和气候变化的影响，生产中使用的高抗茎腐病的玉米品种不多等因素，致使田间病原菌数量增加，我国玉米茎腐病有逐渐加重的趋势。针对玉米茎腐病危害逐年加重的现状，本文系统综述了玉米茎腐病致病菌、发病症状表现、病情分级标准、病害侵染规律、抗性鉴定评价方法等方面的研究进展情况，并提出了玉米茎腐病的防治策略。     

当前农民生态道德教育的问题与对策

分析了我国农民生态道德的现状和发展农民生态道德教育的意义,在此基础上提出了进一步加强农民生态道德教育的对策.     

西方国家碳税收入使用政策比较及其启示

碳税收入使用政策是西方国家碳税制度设计的一项重要内容，其主要基于税收中性原则，将税收收入或投资于环保节能项目，或以税式支出方式降低纳税人负担，确保碳税收入的循环，实现节能减排的目标。在我国碳税制度设计的构想中，应借鉴西方国家税制经验，结合本国现实情况，科学合理地设计碳税收入使用政策，确保碳税调节功能的充分发挥，将碳税发展成培育战略性新兴产业的重要政策工具之一。     

水肥一体化中水肥混合效果数值模拟研究

为研究水肥一体化技术中的水肥混合特性,以流体力学中的两相流理论为基础,针对水肥混合过程中混合时间、混合区间长度、流速及管径对其混合效果的影响进行相应的数值模拟研究。结果表明,混合时间及混合区间长度越长有利于提高水肥混合效果及最终水肥混合均匀性;水肥流速比较低时管内水肥混合的均匀性较好,且水肥流速越大则其混合效果及均匀性越好;水肥流速较低时输水管及输肥管的管径比对水肥混合均匀性的影响较大,两者管径比越小则混合效果越好,随着流速的提高两者管径比对其混合效果的影响逐渐减弱。     

Nutrient cycling and biomass flows in a low-quality forest stand improvement system in the Lesser Khingan Range of China

The material flow and bulk internal flow analyses were used to establish a material accumulation and cycling model for a low-quality forest stand improvement system and a series of processes were considered. The model was applied in a one-hectare low-quality forest plot in the Lesser Khingan Range of China. Results showed that during 1997–2007, the stands absorbed 270.19 kg of N, 74.28 kg of P, and 124.39 kg of K from soils, 51.82 kg of N and 2.38 kg of P were directly absorbed by foliage, and 16.25 kg of K was released to soils by eluviation. Until 2007, the accumulated nutrients in the stands included 236.91 kg of N, 65.28 kg of P, and 108.55 kg of K. When horizontal strip clearcutting was applied in 2007, 50% accumulated nutrients in the stands were shifted due to harvesting operations, and 212.74 kg of N, 26.97 kg of P, and 98.88 kg of K were accumulated in soils, declining by 9.47% for N, 3.68% for P, and 17.60% for K, respectively, compared with year 1997. 94.61 t per hectare of biomass was generated, of which the biomass in stands accounted for 87.36%. The felled tree biomass was 36.89 t per hectare, of which 84.90% and 10.03% of biomass were utilized in terms of logs and other means, and the rest was left on site.     

论韶关地区道路绿化植物的科学选择与配置

韶关地区道路绿化树种大多数是从南部珠三角地区和北部湖南地区引进，可能存在所引进树种是否适应韶关气候的问题。因此，如何运用科学的方法选择与配置道路绿化植物和确定合适的种植位置就成为道路绿化工程的关键。     

Neuroprotective effect of fasudil combined with bone marrow-derived neural stem cells on mice with experimental autoimmune encephalomyelitis

AIM: To explore the neuroprotective effect of fasudil combined with bone marrow-derived neural stem cells (BM-NSCs) on the mice with experimental autoimmune encephalomyelitis (EAE). METHODS: Female C57BL/6 mice (8~10 weeks old, n=32) were immunized with myelin oligodendrocyte glycoprotein 35-55 (MOG_35-55) to establish chronic EAE model. The mice were randomly divided into control (ddH₂O) group, fasudil group, BM-NSCs group, and fasudil+BM-NSCs group. The clinical score and body weight were recorded every other day. The expression of neurotrophic factors was determined by immunofluorescence staining. RESULTS: In comparison with ddH₂O group, fasudil combined with BM-NSCs delayed onset and ameliorated severity of EAE. The numbers of brain-derived neurotrophic factor, glial cell-derived neurotrophic factor, nerve growth factor, neurotrophin-3 and ciliary neurotrophic factor positive cells in fasudil group, BM-NSCs group and fasudil+BM-NSCs group were all increased in various extents. In particularly, the expression of these neurotrophic factors in fasudil+BM-NSCs group was significantly higher than that in the mice treated with fasudil or BM-NSCs alone (P<0.01). CONCLUSION: Fasudil combined with BM-NSCs promotes the expression of neurotrophic factors and improves microenvironment of central nervous system, thus playing a positive role in neural restoration and regeneration through a synergistic and superimposed effect.