饲料中维生素A对青鱼幼鱼生长、血清生化指标和肝脏糖脂代谢酶活性及基因表达的影响

为研究饲料中维生素A(VA)对青鱼幼鱼生长、血清生化指标和肝脏糖脂代谢相关酶活性及基因表达的影响,实验选取360尾初始体质量为(6.10±0.10) g的青鱼幼鱼,随机分配至3个实验组中,每个实验组设置3个平行。采用单因素实验设计,以无维酪蛋白和明胶为蛋白源、菜籽油为脂肪源、糊精为糖源,同时添加矿物质混合物和维生素混合物(无VA添加)配制成3组实验饲料,分别以饲料1 (Diet1)、饲料2 (Diet2)和饲料3 (Diet3)表示。在饲料1、饲料2和饲料3中分别添加0、2 200和20 000 IU/kg VA醋酸酯(500 000IU/g),经高效液相色谱法(Agilent-1100, Agilent,美国)检测后实验饲料中VA的实际含量分别为178.2、2 058.9和18 436.2 IU/kg,养殖周期为8周。结果显示:饲料中VA缺乏会显著降低青鱼幼鱼的增重率(WGR)和特定生长率(SGR);VA缺乏会显著降低血清血糖(GLU)、甘油三酯(TG)和低密度脂蛋白(LDL)浓度,增加总胆固醇(TCH)浓度。饲料中添加2 058.9IU/kg VA能显著提高肝脏己糖激酶(HK)、磷...     

“杜蒙萨”三元杂交羔羊产肉性能测定试验

为更好地指导乌兰察布市优质育肥羔羊生产体系建设,进一步了解在相同的饲养管理条件下,“杜蒙萨”三元杂交羔羊与当地蒙古羊羔羊在养殖效益方面的对比情况,进行了“杜蒙萨”三元杂交羔羊产肉性能试验。试验分为试验组（“杜蒙萨”三元杂交羔羊组）和对照组（蒙古羊羔羊组）2个组,每组采取随机取样方式选择试验用羊。经过体重测定与屠宰试验测定,统计试验数据,通过分析试验数据进行经济效益对比。试验结果显示,在自然环境和饲养管理条件完全相同的条件下,经过对生长及产肉性能测定数据的整理、统计和分析,“杜蒙萨”三元杂交组羔羊平均初生重、断乳重、5月龄出栏活重、5月龄平均日增重均高于对照组蒙古羊羔羊。试验充分证明了在牧区推广“杜蒙萨”三元杂交羊生产体系建设,是实现牧区草原生态高效养殖和促进农牧民养殖户提质增效的有效途径之一。     

禾本科作物节单位研究进展

节单位(phytomer)是禾本科作物形态结构基本组成单元,是模块化理论在禾本科作物形态结构认知上的延伸,也是禾本科作物结构与功能的研究尺度之一。基于节单位结构与功能的模块化属性,综述了禾本科作物节单位的概念及其在作物结构与功能研究中的应用。首先从节单位的概念出发,介绍了节单位概念发展过程;然后分别从结构和功能的角度对基于节单位的禾本科作物研究进展进行了总结,结构研究主要从拓扑结构、几何结构、形态建成三方面阐述,功能研究主要从光合产物分配、生育期预测和发育过程等方面进行分析;最后从节单位定义的规范性、几何结构重建、表型数据提取及显微结构等方面对基于节单位的禾本科作物结构功能研究进行了展望。     

Effect of 1α, 25-dihydroxyvitamin D3 on T helper cell 17 and expression of related cytokines in penetrating keratoplasty in mice

AIM: To evaluate the effects of 1α, 25-dihydroxyvitamin D3 on T helper cell 17 (Th17 cells) and its related cytokines in a mouse model of corneal allograft transplantation. METHODS: C57BL/6 mice were transplanted with corneal grafts from BALB/c mice and treated intraperitoneally with 1.0 μg 1α, 25-dihydroxyvitamin D3 or soybean oil every other day after operation. The transparency of the corneal grafts was evaluated for potential rejection signs by slit lamp biomicroscopy and histopathology. The expression levels of IL-17, RORγt and IFN-γ in the spleen were measured by real-time PCR. Moreover, the protein expression of RORγt and IL-17 in the peripheral blood was analyzed by Western blotting. IL-17 and IFN-γ in peripheral blood were measured by flow cytometry. RESULTS: 1α, 25-dihydroxyvitamin D3 significantly inhibited the rejection of the corneal allograft and reduced the numbers of inflammatory infiltrates in the corneal graft. In the spleen, 1α, 25-dihydroxyvitamin D3 treatment reduced the expression levels of IL-17, RORγt and IFN-γ. In the peripheral blood, 1α, 25-dihydroxyvitamin D3 treatment downregulated the expression levels of RORγt, IL-17 and IFN-γ. CONCLUSION: The effects of 1α, 25-dihydroxyvitamin D3 on suppressing corneal transplantation-induced allograft rejection in mice are closely associated with its modulation on IL-17 and related cytokine RORγt.     

基于三维激光扫描技术的塌陷土地复垦规划研究

通过对三维激光扫描获得的海量点云数据进行处理和分析,直观、真实地显示出塌陷区内和周边地形,得到精密地形图;根据因地制宜、可持续性、综合效益和统一性的土地复垦原则,设计出针对塌陷区的两种土地复垦方案,并择优选用。三维激光扫描技术用于土地复垦实现了高效率、高精度和低成本的目标。     

一例3D打印义齿修复猕猴牙齿的案例

对1只下颌中切牙缺失的猕猴进行CT检查后,通过入口式3D扫描、打印义齿、手术安装,并进行术后评估。结果发现CT检查确定固定桥修复方案,3D扫描打印义齿较为精准。固定桥未出现松动、变形等,与基牙颈部密合,边缘伸展合适,邻接关系良好,咬合协调,无翘动。固定桥与牙龈关系良好,未见牙周炎发生。采食食物品种明显增加,咀嚼行为正常。采食量明显上升,差异显著(P<0.05)。利用3D打印义齿技术对一例下颌中切牙缺失的猕猴进行牙科修复,为首次报道,效果良好,可以推广。     

柑桔“石头果”发病原因及防治措施分析

柑桔“石头果”是由于树体缺素引起的一种生理性病害。近年来,在永安市某些柑桔园发生频繁,为害轻的“石头果”减产1%~20%,为害重的减产50%以上,严重影响了柑桔的产量和品质。本文通过对柑桔“石头果”表现症状、发生原因的调查,分析了柑桔“石头果”产生的原因,提出了综合防治措施,以达到丰产、稳产、提质的目的。     

Evaluation of vitamin A status on myogenic gene expression and muscle fiber characteristics

A randomized complete block design experiment with 30 yearling crossbred steers (average BW = 436.3 ± 39.8 kg) fed a steam-flaked corn-based diet was used to evaluate the effects dietary vitamin A (Rovimix A 1000; DSM Nutritional Products Ltd., Sisseln, SUI) supplementation on myogenic gene expression and skeletal muscle fiber characteristics during the finishing phase. Steers were blocked by BW (n = 5 blocks; 6 steers/block), randomly assigned to pens (n = 2 steers/pen), and one of the following treatments: no added vitamin A (0 IU; 0.0 IU/kg of dietary dry matter intake of additional vitamin A), vitamin A supplemented at the estimated requirement (2,200 IU; 2,200 IU/kg of dietary dry matter (DM) of additional vitamin A), and vitamin A supplemented at 5× the estimated requirement (11,000 IU; 11,000 IU/kg of dietary DM of additional vitamin A). After all treatments underwent a 91-d vitamin A depletion period, additional vitamin A was top-dressed at feeding via a ground corn carrier. Blood, longissimus muscle, and liver biopsy samples were obtained on days 0, 28, 56, 84, and 112. Biopsy samples were used for immunohistochemical and mRNA analysis. Sera and liver samples were used to monitor circulating vitamin A and true vitamin A status of the cattle. Expression for myosin heavy chain (MHC)-I diminished and rebounded (P = 0.04) over time. The intermediate fiber type, MHC-IIA, had a similar pattern of expression (P = 0.01) to that of MHC-I. On day 84, C/EBPβ expression was also the greatest (P = 0.03). The pattern of PPARγ (P < 0.01) and PPARδ (P < 0.01) expression seemed to mimic that of MHC-I expression, increasing from days 84 to 112. Distribution of MHC-IIA demonstrated a change over time (P = 0.02). Muscle fiber cross-sectional area increased by day (P < 0.01) for each MHC with the notable increase between days 0 and 56. Total nuclei density decreased (P = 0.02) over time. Cells positive for only Myf5 increased (P < 0.01) in density early in the feeding period, then declined, indicating that satellite cells were fusing into fibers. The dual-positive (PAX7+Myf5) nuclei also peaked (P < 0.01) around day 56 then declined. These data indicated that gene expression associated with oxidative proteins may be independent of vitamin A status in yearling cattle.     

小麦田合理施氮的研究

小麦田对氮肥需求和施肥时间的要求非常严格。在种植中,常见叶片短、窄,茎部叶片先发黄;植株瘦小、直立,分蘖少,穗粒少而小。合理的施氮时间是影响小麦产量的最主要因素。氮肥是小麦生长所必需的大量元素。因此,合理施用氮肥对小麦生长至关重要。     

Numerical analysis of soil water dynamics in a soil column with an artificial capillary barrier growing leaf vegetables

An artificial capillary barrier (CB ), which consists of two layers of gravel and coarse sand, was used to improve the soil water retention capacity of the root zone of sandy soil for the cultivation of Japanese spinach (Brassica rapa var. perviridis ). The performance of a CB under specific conditions can be evaluated using numerical simulations. However, there have been relatively few numerical studies analyzing soil water dynamics in CB systems during crop growth. The objectives of this study were (i) to evaluate the performance of a CB during the cultivation of Japanese spinach irrigated at different rates and (ii) to investigate the effect of the irrigation schedule on root water uptake. Numerical analysis was performed using HYDRUS ‐1D after the soil hydraulic properties of the CB materials were determined. In most cases, the HYDRUS ‐1D results agreed well with the experimental soil water content data without any calibration when the dual‐porosity model describing soil hydraulic properties was used for gravel and coarse sand. We found that the dual‐porosity model was able to attenuate the unrealistically steep reduction in the unsaturated hydraulic conductivity predicted by the single‐porosity model. The numerical simulations also showed that the CB played an important role in maintaining plant‐available water in the root zone while maximizing the water use efficiency. The numerical simulations revealed that the irrigation frequency could be reduced by half during the early growth stage, and the water use efficiency could be greatly improved with the CB layer installed.