纳米Fe3O4负载酸改性炭对水体中Pb2+、Cd2+的吸附

为探讨纳米Fe₃O₄负载联合硝酸改性椰壳炭对Pb²⁺、Cd²⁺单一及复合溶液的吸附特性，通过静态吸附实验，针对吸附剂的表面特性、投加量、溶液初始pH、吸附时间、重金属初始浓度等影响因素进行了探讨，应用等温吸附模型及吸附动力学模型对吸附特性进行了研究。结果表明，纳米Fe₃O₄负载酸改性炭比表面积较未改性椰壳炭增加了221.03 m²·g^-1，表面含氧官能团如O-H、C=O、C-O-C增加，芳香性增强，等电点提高至5.68。从经济效率角度考虑5 g·L^-1为合理吸附剂用量，pH为5.0时，吸附效果最好，吸附在4 h达到平衡。准二级动力学模型对吸附的拟合度更高，吸附主要是化学吸附，吸附由快速外扩散和颗粒内扩散共同作用，Pb²⁺、Cd²⁺的吸附分别更符合Langmuir和Freundlich等温吸附模型。纳米Fe₃O₄负载酸改性椰壳炭对Pb²⁺、Cd²⁺的最大吸附量（Q_m）分别达42.54 mg·g^-1和25.79 mg·g^-1，为未改性椰壳炭的1.87倍和2.23倍，复合溶液中Pb²⁺、Cd²⁺的Q_m分别为单一溶液的65.16%和54.21%，这揭示了离子共存条件下的吸附竞争现象。研究表明，纳米Fe₃O₄负载联合硝酸改性提高了椰壳炭对Pb²⁺、Cd²⁺的吸附能力，且Pb²⁺的吸附性能及吸附竞争性优于Cd²⁺。     

增氧方式对水芹菜-微生物联合作用处理冬季养殖废水的影响

为探究不同增氧方式对水芹菜-微生物联合作用处理养殖废水消化液及微生物群落结构变化的影响，设置循环和曝气两组试验，以静置处理作为对照，共运行35 d，间隔7 d取样，测定常规水质指标，在试验开始和结束时分别测定水芹菜生长情况，并采用高通量测序技术对微生物群落结构进行分析。结果显示，经过35 d的处理，静置组、曝气组和循环组的DO（溶解氧）分别达到0.60、10.38 mg·L^-1和10.85 mg·L^-1；静置培养的水芹菜长势最好，相对生长速率为0.03 g·g^-1·d^-1；三种处理方式对水质的净化效果差异显著，循环组的水质净化效果最好，COD（化学需氧量）、NH₃-N（氨氮）和TN（总氮）的去除率分别达89.89%、69.40%和77.65%；黄杆菌属（Flavobacterium）的相对丰度从43.21%下降到0.16%，克里斯滕森菌属（Christensenellaceae）和瘤胃球菌属（Ruminococcaceae）的相对丰度则大幅增加。水芹菜在冬季于养殖废水消化液中可以正常生长，曝气和循环处理可以明显提高净化效率；黄杆菌属和假单胞菌属（Pseudononas）是脱氮的功能菌属，梭菌纲（Clostridia）的大量繁殖有利于COD的去除。     

Regulatory role of l-proline in fetal pig growth and intestinal epithelial cell proliferation

l-proline (Pro) is a precursor of ornithine, which is converted into polyamines via ornithine decarboxylase (ODC). Polyamines plays a key role in the proliferation of intestinal epithelial cells. The study investigated the effect of Pro on polyamine metabolism and cell proliferation on porcine enterocytes in vivo and in vitro. Twenty-four Huanjiang mini-pigs were randomly assigned into 1 of 3 groups and fed a basal diet that contained 0.77% alanine (Ala, iso-nitrogenous control), 1% Pro or 1% Pro + 0.0167% α-difluoromethylornithine (DFMO) from d 15 to 70 of gestation. The fetal body weight and number of fetuses per litter were determined, and the small and large intestines were obtained on d 70 ± 1.78 of gestation. The in vitro study was performed in intestinal porcine epithelial (IPEC-J2) cells cultured in Dulbecco''s modified Eagle medium-high glucose (DMEM-H) containing 0 μmol/L Pro, 400 μmol/L Pro, or 400 μmol/L Pro + 10 mmol/L DFMO for 4 d. The results showed that maternal dietary supplementation with 1% Pro increased fetal weight; the protein and DNA concentrations of the fetal small intestine; and mRNA levels for potassium voltage-gated channel, shaker-related subfamily, member 1 (Kv1.1) in the fetal small and large intestines (P < 0.05). Supplementing Pro to either gilts or IPEC-J2 cells increased ODC protein abundances and polyamine concentrations in the fetal intestines and IPEC-J2 cells (P < 0.05). In comparison with the Pro group, the combined administration of Pro and DFMO reduced the expression of ODC protein and spermine concentration in the fetal intestine, as well as the concentrations of putrescine, spermidine and spermine in IPEC-J2 cells (P < 0.05). Meanwhile, the percentage of cells in the S-phase and the mRNA levels of proto-oncogenes c-fos and c-myc were increased in response to Pro supplementation, whereas depletion of cellular polyamines with DFMO increased tumor protein p53 (p53) mRNA levels (P < 0.05). Taken together, dietary supplementation with Pro improved fetal pig growth and intestinal epithelial cell proliferation via enhancing polyamine synthesis.     

达州市花椒产业发展现状与对策

文章通过对达州市花椒产业发展现状和存在问题进行了分析,提出了促进达州花椒产业健康发展的对策。     

高压雾化设备在现代农业中的应用

高压雾化设备指利用高压雾化主机将经过精密过滤处理的水,输送到造雾专用高压管网,最后到达造雾专用喷头喷出成雾的系统。高压雾化设备在现代农业中主要应用在设施农业降温、加湿、植保以及景观等方面。其中,设施温室降温时依据地域的气候条件、系统投资、后期维护费用、运行费用、降温效果以及对温室湿度的影响等各种因素,来综合考虑高压雾化与其他降温方式联合使用降温,以期达到最佳效果。根据工程项目使用高压雾化设备的经验总结了相关建议,以期为实际生产提供参考。     

宽口裂腹鱼消化系统解剖和组织学观察

该研究采用解剖、石蜡切片和HE染色法对宽口裂腹鱼(Schizothorax eurystomus)消化系统解剖特征和组织切片进行观察。结果显示,其消化管管壁由内向外分别为黏膜层、黏膜下层、肌层和浆膜,主要差别在于黏膜层和肌层。食道黏膜上皮为复层扁平上皮,上皮间分布有大量杯状细胞;前肠和中肠黏膜上皮为单层柱状上皮,明显可见刷状缘、杯状细胞和淋巴细胞分布其间;后肠黏膜上皮为假复层柱状上皮,其间也有杯状细胞和淋巴细胞分布,肠道中杯状细胞由前至后逐渐增多。食道肌层为内环外纵的骨骼肌;前肠肌层为内环外纵的平滑肌;中肠和后肠为内螺旋外环行的平滑肌。消化腺由肝脏和胰腺组成,胰腺弥散状分布在肝脏中,肝小叶不明显。研究表明,宽口裂腹鱼消化系统组织学特征与其食性具有适应性。     

河西走廊荒漠绿洲过渡带沙丘不同生境沙拐枣种群扩张特征研究

本研究以河西走廊荒漠绿洲边缘关键天然固沙植物沙拐枣为研究对象,对流动沙丘、固定沙丘不同生境的沙拐枣种群扩张特征进行调查,旨在更全面地认识其种群扩张特征和对干旱高温环境的适应对策。结果表明：（1）沙丘不同生境,沙拐枣种群扩张方式存在显著差异：在流动沙丘,丘间低地和过渡带以有性繁殖为主,无性繁殖为辅;迎风坡和背风坡以无性繁殖为主;而随着流动沙丘固定,种群以有性繁殖为主,无性繁殖数量和所占比重显著下降,并导致种群数量下降。（2）不同生境中沙拐枣种群密度与年龄均呈显著负相关,种群以幼龄苗为主,种群最大年龄出现在丘间低地,为36龄。（3）流动沙丘不同生境根状茎主要为2年生,多年生根状茎长度较短;而固定沙丘不同生境根状茎年龄结构较为均衡。     

川渝地区地方和育成大豆品种SSR标记多样性分析?

利用基本均匀分布于大豆20条染色体的135对SSR标记，对232份包括6个地方品种地域亚群和1个育成品种亚群进行全基因组扫描。结果表明：所有的标记都有多态性，所有检测到的位点都是纯合基因型，说明所选用品种高度纯合，每个标记存在2～4个等位变异，平均2.66个。亚群多态信息含量变异范围0.2751-0.3165，整个群体为0.3208；亚群内Nei遗传距离变异范围0.325 8～0.359 4，整个群体为0.3711，说明川渝地区大豆遗传变异较小。亚群间的遗传一致度（GI ≥ 0.8862）较高，亚群间遗传距离（GD ≤ 0.1208）较小，地方品种亚群间遗传差异更小，育成品种亚群与自然地域亚群的遗传差异相对较大。亚群间基因分化系数（Fst）平均为 0.0722，基因流（Nm）平均为 3.214，说明不同亚群之间存在一定的基因交流。主坐标分析表明第一、二和三主成分分别解释总变异的4.97%、3.54%和3.33%。来自同一区域的品种资源基本聚集在同一亚群，聚类分析同样表明同一自然地域亚群品种资源虽不能完全聚集到同一个遗传类群中，但具有一定的聚集效应，说明川渝大豆品种资源遗传变异与地理位置有一定的关系。分子方差分析表明亚群内变异占总变异的97%，亚群间变异仅占总变异的3%。Mantel收敛分析表明地方品种自然地域亚群的遗传距离与所处的地理位置距离（纬度和海拔）呈显著的正相关关系（R2=0.723）。川渝地区大豆种质资源群体遗传丰富度不高，当前的育成品种未蕴含本地区所有遗传变异。     

Reduction in cadmium accumulation in japonica rice grains by CRISPR/Cas9-mediated editing of OsNRAMP5

Cadmium (Cd) intake is harmful to human health and Cd contamination in rice grains represents a severe threat to those consuming rice as a staple food. Knockout of Cd transporters is a promising strategy to reduce Cd accumulation in rice grains. OsNRAMP5 is the major transporter for Cd and manganese (Mn) uptake in rice. Nevertheless, it is uncertain whether knockout of OsNRAMP5 is applicable to produce low Cd rice without affecting plant growth and grain yield. In this study, we adopted CRISPR/Cas9-based gene editing technology to knock out OsNRAMP5 in two japonica varieties. We generated three independent transgene-free osnramp5 mutants and investigated the effect of osnramp5 mutations on Cd accumulation and plant growth. Hydroponic experiments showed that plant growth and chlorophyll content were significantly reduced in osnramp5 mutants at low Mn conditions, and this defective growth in the mutants could be fully rescued by supply of high levels of Mn. Cd and Mn accumulation in both roots and shoots was markedly reduced in the mutants compared to that in wild-type plants. In paddy field experiments, although Cd in flag leaves and grains was greatly reduced in osnramp5 mutants, some agronomic traits including plant height, seed setting rate, and grain number per panicle were affected in the mutants, which ultimately caused a mild reduction in grain yield. The reduced plant growth in the mutants can be attributed to a marked decrease in Mn accumulation. Our results reveal that the manipulation of OsNRAMP5 should be treated with caution: When assessing the applicability of osnramp5 mutants, soil pH and soil water content in paddy fields need to be taken into consideration, since they might affect the levels of available Mn in the soil and consequently determine the effect of the mutation on grain yield.     

兴宁市优质稻高产品种种植示范及其配套技术

近几年来兴宁市积极推广优质稻的生产,种植面积逐年增加。结合兴宁市优质稻栽培实践,总结了目前的示范推广情况,最后提出了配套的技术要点。