不同脂肪酸组成的油脂对LPS诱导的小鼠肠道炎症的影响

目的:比较不同脂肪酸组成的油脂对LPS诱导的小鼠肠道急性炎症的影响,为重症肠道感染提供肠内营养的数据参考。方法:取12w龄雄性C57BL/6J小鼠40只,腹腔注射LPS(3.5mg/kg)24h后,测量空腹体重,随机分为5组:玉米油组(ω-6脂肪酸)、橄榄油组(ω-9脂肪酸)、紫苏油组(ω-3脂肪酸)、中长链油组(中链脂肪酸)、LPS损伤组(灌胃葡萄糖)。根据组别灌胃小鼠,7d后取小鼠腹主动脉血及小肠组织,测定细胞因子水平和TLR4信号通路中相关分子的mRNA表达,并进行小肠组织病理切片观察。研究期间每日测量小鼠体重。结果:研究结束时,各组小鼠体重均升高,以橄榄油组和紫苏油组最高,且与LPS损伤组和玉米油组比较均有显著性差异(P0.05);血和小肠中TNF-α、IL-1β、IL-6水平及小肠TLR4、My D88和TNF-α的mRNA表达以中长链油组最低,与LPS损伤组和玉米油组比较均有显著性差异(P0.05),而与橄榄油组和紫苏油组无显著性差异(P0.05)。小肠组织病理切片结果显示:各组小鼠小肠粘膜均有不同程度的损伤,以LPS损伤组损伤最明显,玉米油组次之,橄榄油组处于中等水平,中长链油组与紫苏油组损伤较轻。结论:中链脂肪酸、ω-3脂肪酸和ω-9脂肪酸来源的油脂对LPS诱导的肠道炎症的修复作用均优于ω-6脂肪酸来源的油脂和葡萄糖,机制可能为抑制肠道TLR4信号传导途径相关因子表达,减少促炎细胞因子释放。     

熊果酸对酒精诱导的大鼠小肠黏膜屏障损伤的保护作用

目的:研究熊果酸(UA)对酒精诱导的大鼠小肠黏膜屏障损伤的保护作用。方法:将SD大鼠随机分为正常对照组,每日给予生理盐水灌胃;酒精模型组,每日给予体积分数50%酒精8 mL/(kg bw·d)灌胃2周,第3周开始以12 mL/(kg bw·d)灌胃;熊果酸组,每日给予150 mg/(kg bw·d)熊果酸,1 h后再灌酒精,剂量同酒精模型组;谷氨酰胺组,每日给予300 mg/(kg bw·d)谷氨酰胺,酒精灌胃同熊果酸组,试验持续8周。采用HE染色法观察大鼠小肠黏膜组织病理学变化;利用透射电镜观察小肠黏膜细胞超微结构的改变;检测了大鼠血浆D-乳酸(D-LA)、肠脂肪酸结合蛋白(FABP2)、肿瘤坏死因子-α(TNF-α)和白介素-1β(IL-1β)质量浓度的改变;测定了小肠组织中叉头框转录因子O4(FOXO4)、磷酸化叉头框转录因子O4(p-FOXO4)、和闭锁小带蛋白-1(ZO-1)的表达水平。结果:酒精模型组小肠绒毛萎缩、变短,排列不整,紧密连接肿胀,有炎性细胞浸润。与酒精模型组相比,熊果酸组和谷氨酰胺组大鼠小肠黏膜病理变化有所改善;血浆D-LA、FABP2、TNF-α和IL-1β质量浓度明显降低;p-FOXO4表达量减少、ZO-1表达量升高;各组FOXO4表达水平无显著差异。结论:熊果酸可以改善酒精诱导的大鼠小肠黏膜屏障损伤,其作用机制可能与改善肠黏膜通透性,抑制FOXO4蛋白发生磷酸化,进而减少促炎因子TNF-α和IL-1β的释放有关。     

南极磷虾油对小鼠肠黏膜屏障的保护作用及机制

为探究南极磷虾油对脂多糖所致肠黏膜屏障损伤的预防作用及其机制,选取32只雄性小鼠随机分为4组:正常对照组、模型组(脂多糖组)、南极磷虾油干预组和鱼油干预组.前两组灌胃橄榄油,后两组分别灌胃400 mg/kg(以体重计)以橄榄油为溶剂稀释的南极磷虾油或鱼油,每日1次.连续干预4周后,正常组小鼠经腹腔注射生理盐水,其余3组注射10 mg/kg(以体重计)脂多糖,6h后处死小鼠.苏木精-伊红染色后,观察小鼠小肠组织病理学变化;测定小鼠血清和小肠中二胺氧化酶活性,蛋白免疫印迹法分析紧密连接蛋白和诱导型一氧化氮合酶蛋白表达;检测髓过氧化物酶和一氧化氮含量,实时荧光定量PCR法检测促炎细胞因子mRNA表达;蛋白免疫印迹法分析TLR4/NF-κB信号通路相关蛋白表达水平.实验结果显示,南极磷虾油预防性干预能显著抑制脂多糖所致小鼠小肠绒毛长度与隐窝深度比值的降低;下调血清二胺氧化酶水平,提高小肠二胺氧化酶活性,增加肠道紧密连接蛋白Claudin-1、Occludin和ZO-1蛋白表达水平;抑制髓过氧化物酶活性、诱导性一氧化氮合酶蛋白表达和一氧化氮含量升高,降低TNF-α、IL-1β和IL-6的mRNA表达以及TLR4/NF-κB信号通路相关蛋白表达水平.研究结果表明,南极磷虾油可通过抑制TLR4/NF-κB信号通路预防脂多糖所致肠黏膜屏障损伤,且其效果优于传统鱼油.     

异食癖对哺乳期犊牛肠道黏膜通透性及免疫因子表达的影响

为研究异食癖对哺乳期犊牛肠道通透性及免疫因子表达的影响,选择出生3周左右,体重相近的犊牛(54.7±5.83 kg)作为研究对象,根据犊牛舔食牛毛、沙子等行为,随机选择12头表现为被毛粗乱、消瘦、腹泻和发育受阻等症状的犊牛为异食癖组,健康、无食牛毛、沙子等症状的12头犊牛作为对照组。至犊牛断奶(56 d),每组随机选择5头进行屠宰,取十二指肠组织,利用Real-time PCR技术分析犊牛肠道紧密连接蛋白-1(ZO-1)、咬合蛋白(Occludin)、闭合蛋白(Claudin)、Toll样受体4(TLR4)、肿瘤坏死因子-α(TNF-α)和白细胞介素1(IL-1β)的m RNA在肠道黏膜上的表达水平变化。结果表明,异食癖犊牛肠黏膜蛋白ZO-1相对表达量显著低于对照组犊牛(P0.05),Occludin和Claudin相对表达量低于对照组,但差异不显著(P0.05),异食癖犊牛肠道黏膜通透性增加,免疫因子TLR4相对表达量显著低于对照组(P0.05),TNF-α和IL-1β相对表达量极显著高于对照组(P0.01),异食癖犊牛肠道免疫因子表达下调,肠道黏膜炎症因子表达上调,肠道抗氧化能力减弱。     

壳寡糖对酒精诱导的大鼠肠道损伤的干预作用

目的：研究壳寡糖（chitooligosaccharide,COS）对慢性饮酒诱导的肠道损伤的干预作用。方法：将Wistar雄性大鼠随机分为空白对照组、模型组、COS低剂量组、COS中剂量组和COS高剂量组5 组,除空白对照组,其余各组通过连续42 d灌胃4.5 g/kg mb酒精构建肠道损伤模型,COS组酒精灌胃前灌胃COS。结果：与模型组相比,COS可以显著改善大鼠小肠平滑肌伸缩性（P＜0.05）,恢复小肠健康水平,降低血浆中D-乳酸水平、二胺氧化酶活力及白细胞介素（interleukin,IL）-1β、肿瘤坏死因子-α（tumor necrosis factor-α,TNF-α）、IL-6等促炎因子、丙二醛和蛋白质羰基水平（P＜0.05）以及抑制claudin-4蛋白的基因表达（P＜0.05）,高剂量COS可以显著提高紧密连接蛋白Occludin（P＜0.05）和ZO-1（P＜0.05）的基因表达,中、高剂量的COS可以显著降低小肠组织中炎症因子IL-6、IL-1β和TNF-α的基因表达量（P＜0.05）。结论：COS通过提高小肠健康水平、提高肠黏膜屏障、降低炎症反应及减缓氧化损伤,缓解慢性酒精导致的大鼠肠道损伤。     

玉米黄素对内质网应激引发的SH-SY5Y细胞凋亡的保护作用

目的:研究玉米黄素对内质网应激引起的细胞凋亡的保护作用。试验分为空白对照组、衣霉素(TM)损伤组(5 μg/mL)、玉米黄素保护组(5 μmol/L)和损伤加保护组。采用Caspase 3试剂盒检测Caspase 3活性的变化;采用Western Blot法测定凋亡相关蛋白PERK、CHOP,PERK下游信号分子elF2α和ATF4,以及自噬相关蛋白Beclin 1。结果显示:与TM模型组相比,玉米黄素处理后PERK及其下游调控蛋白elF2α和ATF4的表达能力显著下降(P<0.01),Beclin 1的水平显著升高(P<0.01)。与未加自噬抑制剂相比,玉米黄素组的GRP78水平显著升高(P<0.01)。与对照组相比,TM模型组的CHOP蛋白的表达水平极显著升高(P<0.01),而玉米黄素处理组CHOP蛋白的表达水平极显著低于TM模型组(P<0.01)。结论:玉米黄素能减轻由内质网应激引起的损伤作用,并且可逆转TM引起的损伤。其作用机制是:玉米黄素通过抑制PERK通路,进而抑制GRP78与ERS感受器的分离,降低促凋亡因子CHOP的水平,通过调控保护性自噬来缓解ERS。     

黑灵芝多糖对免疫抑制小鼠肠道黏膜形态及肠道黏膜免疫的影响

目的：探究黑灵芝多糖对免疫抑制小鼠肠道黏膜形态及肠道黏膜免疫的影响。方法：腹腔注射环磷酰胺构建免疫抑制小鼠模型,将小鼠分为6 组：正常对照组、模型组、阳性对照组以及黑灵芝多糖低、中、高剂量（25、50、100 mg/（kg·d））组,灌胃期间每天记录小鼠体质量并观察其生活状态,空肠组织进行切片病理学观察,酶联免疫吸附实验测定肠道白细胞介素（interlrukin,IL）-6、IL-10、肿瘤坏死因子-α（tumor necrosis factor-α,TNF-α）及干扰素-γ（interferon-γ,IFN-γ）的含量,反转录定量聚合酶链式反应分析T-bet、GATA-3 mRNA相对表达水平。结果：与模型组相比,低、中、高剂量黑灵芝多糖有助于体质量回升,改善肠道黏膜形态结构,提高IL-6、IL-10、TNF-α、IFN-γ细胞因子含量,增强T-bet、GATA-3 mRNA相对表达水平,使Th1/Th2平衡向Th1偏移。结论：黑灵芝多糖可改善免疫抑制小鼠的肠道黏膜形态,调节免疫抑制小鼠的肠道黏膜免疫。     

竹节参总皂苷减轻衰老大鼠的神经细胞凋亡

本研究探讨竹节参总皂苷(saponins from Panax japonicus,SPJ)对自然衰老大鼠内质网应激相关蛋白的调节作用以及对神经细胞凋亡的干预作用。雄性SD大鼠随机分为6月龄组、24月龄组、SPJ低剂量组(10mg/kg)和高剂量组(30mg/kg)。Westernblot法检测大鼠皮层和海马内质网应激相关蛋白(GRP78、p-PERK、p-EIF2α、ATF4、ATF6、p-IRE1、XBP1)以及凋亡相关蛋白(p-JNK、CHOP、Bcl-2、Bax)表达变化。结果显示,与6月龄组相比,24月龄组皮层/海马组织中GRP78、p-PERK、p-EIF2α、ATF4、ATF6、p-IRE1、XBP1和Bcl-2/Bax蛋白表达分别下降了80%/59%、82%/78%、79%/77%、94%/74%、72%/66%、78%/81%、82%/71%和90%/92%,p-JNK/JNK、CHOP蛋白表达分别上升了1/1.72、3.33/1.33倍。给予不同剂量竹节参总皂苷干预后,均能明显上调内质网应激相关蛋白和Bcl-2/Bax的表达水平,下调促凋亡蛋白表达水平。研究结果表明,竹节参总皂苷能通过上调内质网应激相关蛋白以及抗凋亡蛋白的表达水平,下调促凋亡蛋白的表达,从而维持衰老大鼠脑组织的内质网稳态,减少神经细胞凋亡。     

发芽绿豆多酚的降血糖作用及对糖尿病小鼠肠道菌群的影响

目的:探究发芽绿豆多酚提取物对2型糖尿病小鼠的降血糖效果以及对小鼠肠道菌群的影响。方法:根据C57BL/6小鼠体质量,随机分为正常组、T2DM模型组、阳性对照组、发芽绿豆多酚提取物低(50 mg/kg)、中(100 mg/kg)、高(150 mg/kg)剂量组,通过高脂饮食联合腹腔注射链脲佐菌素(STZ)的方法,建立2型糖尿病小鼠模型。灌胃5周后测定小鼠空腹血糖(FBG)、葡萄糖耐量、胰岛素(INS)以及炎症因子白细胞介素IL-6、IL-10、肿瘤坏死因子(TNF-α)、C反应蛋白(CRP)的浓度。收集小鼠粪便,应用16S rRNA平台进行高通量测序,检测多酚提取物干预下糖尿病小鼠肠道菌群的变化。结果:发芽绿豆多酚提取物能够显著降低T2DM小鼠的空腹血糖值,提高葡萄糖耐量水平,降低胰岛素抵抗;显著降低IL-6、TNF-α、CPR的水平,升高IL-10水平,进而缓解糖尿病引起的炎症反应;修复小鼠肝脏组织细胞形态;调节菌群丰度及物种多样性,改善失调的肠道菌群。结论:发芽绿豆多酚提取物通过减轻炎症反应和调节肠道菌群的丰度来改善小鼠的2型糖尿病。     

核桃油对脂多糖诱导小鼠小肠炎性因子TNF-α的影响

探讨核桃油（Walnut oil,WO）对脂多糖（Lipopolysaccharide,LPS）诱导的小鼠急性损伤小肠组织中炎性因子-肿瘤坏死因子α（Tumor necrosis factor alpha,TNF-α）水平的影响。将昆明种小鼠随机分为4组：正常对照组（Con）、LPS组、LPS+WO组和WO组,采用酶联免疫法、实时荧光定量PCR、免疫组化、蛋白印迹和苏木素-伊红染色方法检测小鼠血清与小肠组织炎性因子TNF-α表达水平及其组织病理学变化。结果表明：与Con组相比,LPS组小鼠血清和小肠组织中TNF-α表达水平显著增高,小肠组织病理加重;与LPS组相比,LPS+WO组小鼠血清和小肠组织中TNF-α表达水平显著降低,小肠组织病理减轻;WO组与Con组相比,TNF-α表达水平无显著变化。核桃油可能通过抑制小鼠小肠组织中炎性因子TNF-α的表达水平对LPS诱导的急性肠道损伤发挥保护作用。     

Arsenic(III) oxidation by iron(VI) (ferrate) and subsequent removal of arsenic(V) by iron(III) coagulation

We investigated the stoichiometry, kinetics, and mechanism of arsenite [As(III)] oxidation by ferrate [Fe(VI)] and performed arsenic removal tests using Fe(VI) as both an oxidant and a coagulant. As(III) was oxidized to As(V) (arsenate) by Fe(VI), with a stoichiometry of 3:2 [As(III):Fe(VI)]. Kinetic studies showed that the reaction of As(III) with Fe(VI) was first-order with respect to both reactants, and its observed second-order rate constant at 25 degrees C decreased nonlinearly from (3.54 +/- 0.24) x 10(5) to (1.23 +/- 0.01) x 10(3) M(-1) s(-1) with an increase of pH from 8.4 to 12.9. A reaction mechanism by oxygen transfer has been proposed for the oxidation of As(III) by Fe(VI). Arsenic removal tests with river water showed that, with minimum 2.0 mg L(-1) Fe(VI), the arsenic concentration can be lowered from an initial 517 to below 50 microg L(-1), which is the regulation level for As in Bangladesh. From this result, Fe(VI) was demonstrated to be very effective in the removal of arsenic species from water at a relatively low dose level (2.0 mg L(-1)). In addition, the combined use of a small amount of Fe(VI) (below 0.5 mg L(-1)) and Fe(III) as a major coagulant was found to be a practical and effective method for arsenic removal.     

Mind the (yield) gap(s)

This paper explores the origin of the notion of ??yield gap?? and its use as a framing device for agricultural policy in sub-Saharan Africa. The argument is that while the yield gap of policy discourse provides a simple and powerful framing device, it is most often used without the discipline or caveats associated with the best examples of its use in crop production ecology and microeconomics. This argument is developed by examining how yield gap is used in a selection of recent and influential agricultural policy documents. The message for policy makers and others is clear: ??mind the (yield) gap(s)??, for they are seldom what they appear.     

Iron(VI) and iron(V) oxidation of copper(I) cyanide

Copper(Il) cyanide (Cu(CN)4(3-)) in the gold mine industry presentsthe biggest concern in cyanide management because it is much more stable than free cyanide. Cu(CN)4(3-) is highlytoxic to aquatic life; therefore, environmentally friendly techniques are required for the removal of Cu(CN)4(3-) from gold mine effluent. The oxidation of Cu(CN)4(3-) by iron-(VI) (FeVIO4(2-), Fe(VI)) and iron(V) (FeVO4(3-), Fe(V)) was studied using stopped-flow and premix pulse radiolysis techniques. The stoichiometry with Fe(VI) was determined to be 5HFeO(4-) + Cu(CN)4(3-) + 8H2O - > 5Fe(OH)3 + Cu2+ + 4CNO- +3/202 + 6OH-. The rate law for the oxidation of Cu(CN)4(3-) by Fe(VI) was found to be first-order with each reactant. The rates decreased with increasing pH and were mostly related to a decrease in concentration of reactive protonated Fe(VI) species, HFeO4-. A mechanism is proposed that agrees with the observed reaction stoichiometry and rate law. The rate constant for the oxidation of Cu(CN)4(3-) by Fe(V) was determined at pH 12.0 as 1.35 +/- 0.02 x 10(7) M(-1) s(-1), which is approximately 3 orders of magnitude larger than Fe(VI). Results indicate that Fe(VI) is highly efficient for removal of cyanides in gold mill effluent.     

Reduction of Tc(VII) by Fe(II) sorbed on Al (hydr)oxides

Under oxic conditions, Tc exists as the soluble, weakly sorbing pertechnetate [TcO4-] anion. The reduced form of technetium, Tc(IV), is stable in anoxic environments and is sparingly soluble as TcO2 x nH2O(s). Here we investigate the heterogeneous reduction of Tc(VII) by Fe(II) adsorbed on Al (hydr)oxides [diaspore (alpha-AlOOH) and corundum (alpha-Al2O3)]. Experiments were performed to study the kinetics of Tc(VII) reduction, examine changes in Fe surface speciation during Tc(VII) reduction (M?ssbauer spectroscopy), and identify the nature of Tc(IV)-containing reaction products (X-ray absorption spectroscopy). We found that Tc(VII) was completely reduced by adsorbed Fe(II) within 11 (diaspore suspension) and 4 days (corundum suspension). M?ssbauer measurements revealed thatthe Fe(II) signal became less intense with Tc(VII) reduction and was accompanied by an increase in the intensity of the Fe(III) doublet and magnetically ordered Fe(III) sextet signals. Tc-EXAFS spectroscopy revealed that the final heterogeneous redox product on corundum was similar to Tc(IV) oxyhydroxide, TcO2 x nH2O.     

表没食子儿茶素没食子酸酯的甲基化分子修饰

研究表没食子儿茶素没食子酸酯(EGCG)的甲基化分子修饰。以碘甲烷作为甲基供体,采用化学合成方法研究EGCG 的甲基化分子修饰,并通过HPLC-MS 和NMR 等对反应产物进行结构鉴定。结果表明：采用化学合成方法能有效完成EGCG 的甲基化分子修饰,并分离鉴定出5 个EGCG 甲基化衍生物,分别为4″-Me-EGCG、4′,4″-di-Me-EGCG、5,3′,4′,5′,3″,4″,5″-hepta-Me-EGCG、5,7,3′,4′,3″,4″,5″-hepta-Me-EGCG、5,7,3′,4′,5′,3″,4″,5″-octa-Me-EGCG。     

Supercritical fluid extraction (SFE) of 4(5)-methylimidazole (4-MeI) and 2-acetyl-4(5)-(1,2,3,4)-tetrahydroxybutyl-imidazole (THI) from ground-coffee with high-performance liquid chromatographic-electrospray mass spectrometric quantification (HPLC/ESI-MS).

Two polar analytes, 4(5)-methylimidazole (4-MeI) and 2-acetyl-4(5)-(1,2,3,4)-tetrahydroxybutyl-imidazole (THI), were extracted with supercritical carbon dioxide (CO2) modified with aqueous methanol. The method was applied to a roasted coffee powder with good recovery rates. Method efficiency was compared with that of solid-phase extraction using SCX Disc cartridges and validated for spiked solid matrix. The analytes were determined using isocratic liquid chromatography-mass spectrometry (LC/MS) on an Atlantis HILIC Silica column (150 x 2.1 mm, 3 microm) with 80% methanol and 20% 0.01 mol l-1 ammonium formate as the mobile phase. The limit of quantification was around 1.5 pg for 4-MeI and 2.0 pg for THI. The linearity of the calibration curves was satisfactory as indicated by correlation coefficients of >0.999. The coefficient of variation for the intra-day and inter-day precisions was <4% (n = 6). Accuracy was in the range 98-101%; recovery rates were > or = 98 and > or = 99% for THI and 4-MeI, respectively. Several samples of Arabica coffee from various locations and commercially available 'off-the-shelf' coffee products (Arabica/Robusta mixtures) were analysed to test the method.     

Attractancy of diethyl ether extracts of Arachis hypogaea (Linnaeus) (Papilionaceae), Citrullus lanatus (Thunberg) (Cucurbitaceae) and Irvingia gabonensis var. excelsa (Baillon) (Irvingiaceae) to Oryzaephilus mercator (Fauvel) (Coleoptera: Silvanidae)

Volatiles of the diethyl ether extracts of I. gabonensis, C. lanatus and A. hypogaea attracted 1–7 and 28–42-day-old adult O. mercator when tested in a two-choice pitfall Petri dish bioassay. For both age groups, a significant difference was observed in response between fed and starved adults to the different extracts. Differences in starvation time did not affect responses of individuals in the 1–7-day-old group; a significant effect was observed in the 28–42-day-old group.

Adults, 28–42-day-old were significantly more responsive to virtually all extracts than 1–7-day-old adults. Responses of adults in each age group to the different extracts were not significantly different. The time of trial within the period 0900–1900 h did not significantly affect the response of adults in both age groups, starved for 2 days, to any extract.     

优质农业生产管理指导手册(二)

4病虫害综合防治 病虫害综合防治(IPM)是烟叶生产的一项系统体系,利用病虫害预测预报系统,提供最好的病虫害综合防治决策,重点是协调应用一切可行的办法.病虫害综合防治并不意味着完全排除使用农药,而是在使用其它办法不能使病虫害的种群数保持在可接受的范围时适当使用农药.施用农药的地方应确保安全,并遵守一切法律法规.     

优质农业生产管理指导手册(三)

7 烘烤（调制）和烤房管理 烟叶的正确烘烤和烤房管理对优化烟叶的产量、质量和产值来说是非常关键的因素。烟叶烘烤是保持烟叶产量、质量的最后一道环节。烟叶质量会因烘烤不当而降低，而正确进行烘烤能确保烟叶质量的稳定。然而，若将劣质的鲜烟叶或烟株放入烤房，则不可能提高最终的烟叶质量。