Treatment of a femoral fracture with a titanium locking compression plate distal femur (LCP‐DF) in a young donkey

A closed complete mid‐diaphyseal spiral fracture of the left femur in a one‐year‐old donkey was treated with a 4.5 mm titanium locking compression plate distal femur (LCP‐DF)¹. This plate was originally manufactured for human orthopaedics, primarily for femoral osteosynthesis. The LCP‐DF¹ has a distal head plate that was advantageous in this case because the distal fragment was smaller. Post operative radiographs showed optimal femoral reconstruction and a callus was present 3 weeks after surgery. The donkey was sound at the walk and trot 2 months after surgery. Radiographs taken 5 months after surgery showed stable implants and complete healing without complications.     

乳制品中金黄色葡萄球菌PCR快速检测方法的建立

为快速检测乳制品中的金黄色葡萄球菌,本研究将纳米氢氧化钛和纳米氢氧化锆固定在滤纸片上以去除PCR反应抑制因子,并以Nuc为靶基因,建立一种无需样品前增菌的PCR快速检测方法,同时确定该方法的特异性、灵敏度和实用性,并评估该方法所用试剂在冷冻保存条件下的稳定性与实用性。结果表明,该PCR快速检测方法在检测97株目标菌及83株非目标菌后未出现假阳性或假阴性结果;该方法无需增菌处理,可在4 h内完成检测,检测限为10¹ CFU·25 g^-1或10¹ CFU·25 mL^-1;该方法与传统检测方法在实际乳制品样品中金黄色葡萄球菌的检出率及活菌检测率均一致(符合率100%);此外,该检测方法所用试剂在-20℃冷冻条件下可稳定保存至少12个月。综上所述,本研究建立的PCR快速检测方法特异性强、灵敏度高,且实用性良好,能有效去除样品基质中的PCR反应抑制因子,为乳制品中金黄色葡萄球菌的快速检测提供了参考依据。     

Relative bioavailability of organic bis-glycinate bound copper relative to inorganic copper sulfate in beef steers fed a high antagonist growing diet

To assess the relative bioavailability of bis-glycinate bound Cu, 90 Angus-cross steers (265 ± 21 kg) were blocked by body weight (BW) to pens with GrowSafe bunks and randomly assigned to dietary treatments (14 to 18 steers/treatment): 0 mg supplemental Cu/kg dry matter (DM; CON), 5 or 10 mg supplemental Cu/kg DM as Cu sulfate (CS5; CS10) or bis-glycinate bound Cu (GLY5; GLY10). Steers received a high antagonist growing diet (analyzed 4.9 mg Cu/kg DM, 0.48% S, and 5.3 mg Mo/kg DM). Steers were weighed at the beginning (days 1 and 0) and end (days 125 and 126) of the trial to determine average daily gain (ADG) and gain:feed (G:F). Blood was collected from all steers on days 0, 28, 56, 84, and 126. Liver samples were collected on days −3 or −2 and day 123 or 124. Data were analyzed using ProcMixed of SAS (experimental unit = steer; fixed effect = treatment and block). Plasma Cu was analyzed as repeated measures (repeated effect = day). Plasma and liver Cu concentrations were regressed against total Cu intake using ProcGLM to calculate relative bioavailability of GLY. Final BW and overall ADG were greatest for CS5 and CS10 and least for CON and GLY5 (P = 0.01). Overall, DMI was not affected by treatment (P = 0.14), but overall G:F tended to be greatest for CS5, CS10, and GLY5 and least for CON (P = 0.08). Total and supplemental Cu intake was greatest for steers supplemented either source at 10 mg Cu/kg DM and least for CON (P < 0.01). However, total and supplemental Cu intake was greater for CS5 than GLY5 (P < 0.01). Final liver Cu concentrations were greatest for CS10, least for CON, CS5, and CS10, and intermediate for GLY10 (P < 0.01). Final plasma Cu was greatest for steers supplemented either source at 10 mg Cu/kg DM (P < 0.01). Relative bioavailability of GLY was 82% compared to CS based on liver Cu (P < 0.01) but did not differ based on plasma Cu (P = 0.60). The lesser bioavailability of GLY relative to CS could be due to a high concentration of dietary antagonists and lower solubility of GLY (68.9% relative to CS) in pH conditions (5.2) similar to the ruminal pH of a beef animal consuming a high concentrate diet. Future studies should examine the effects of bis-glycinate bound Cu fed in blended combination with inorganic Cu sulfate to determine the most effective blend of sources for feedlot cattle experiencing varying amounts of dietary Cu antagonists.     

日粮添加钛对山羊瘤胃消化代谢的影响

试验分２个系列研究了日粮中添加铁对山羊瘤胃消化代谢及日增重的影响。系列Ⅰ体内试验结果表明，日粮添加钛不影响瘤胃液ｐＨ值；试验期与对照期相比，瘤胃液氨氮浓度明显升高（Ｐ＜０．０５）；瘤胃液三氯醋酸沉淀蛋白、细菌蛋白及原虫蛋白的含量均显著提高（Ｐ＜０；０５）；添加钦后瘤胃液总挥发性脂肪酸增加，乙酸、丁酸降低，但差异均不显著（Ｐ＞０．０５），而丙酸显著增加（Ｐ＜０．０５），乙酸／丙酸值从对照期的３．１５降至试验期的２．３３（Ｐ＜０．０５），说明添加钛使瘤胃发酵类型趋于丙酸型。添加钛使血清尿素氮明显降低（Ｐ＜０．０５），但对血清总蛋白含量、血糖水平无明显影响（Ｐ＞０．０５）。添加钛能显著提高山羊日增重（Ｐ＜０．０５）。系列Ⅱ体外培养试验结果表明添加钛后人工瘤胃中细菌蛋白、原虫蛋白、氨氮浓度以及挥发性脂肪酸含量等项指标与系列Ⅰ体内试验结果基本一致。     

Physiological responses of tomato roots grown in organ culture to iron-deficiency stress

Roots of the Fe-efficient tomato (Lycopersicon esculentum Mill., cultivar Floradel) were cultured in an inorganic medium supplemented with glycine, thiamine, pyridoxine, and nicotinic acid, with sucrose as an energy and carbon source. Iron was supplied as ferric hydroxyethylethylenediaminetriacetic acid (FeHEDTA) and the initial PH was 5.5. Root growth was limited when less than 40 μm FeHEDTA was supplied. Roots grown at lower Fe concentrations decreased the pH of the FCR assay medium to a greater extent than did roots grown at higher Fe concentrations. Cultured roots grown with 10 μm FeHEDTA had increased levels of ferric chelate reductase (FCR) activity compared to roots grown with either lower or higher concentrations of FeHEDTA. Low FCR activity of roots grown at 2.5 or 5 μm FeHEDTA was attributed either to impaired metabolism due to Fe-deficiency or the lack of sufficient Fe for enhanced FCR formation. Roots of hydroponically grown tomato plants exhibited typical increases in FCR activity with Fe-deficiency. Based on these preliminary results, cultured roots were found to exhibit similar Physiological responses to Fe-deficiency stress as intact root systems. Cultured roots should provide a useful system for the investigation of the role of the root in plant Fe-deficiency stress responses as previously suggested by Bienfait et al.(Plant Physiol., 83, 244–247, 1987).     

蛋氨酸螯合锌对绿头野鸭生产性能的影响

本试验研究蛋氨酸螯合锌对绿头野鸭生长性能及能量和蛋白质代谢的影响,探讨蛋氨酸螯合锌的最佳添加量。试验采用单因子完全随机试验设计,供试绿头野鸭54只,分为3个处理组,每组18只,设3个重复。第Ⅰ组为对照组,添加150 mg/kg硫酸锌;第Ⅱ、Ⅲ组为试验组,分别添加75 mg/kg硫酸锌 150 mg/kg蛋氨酸螯合锌3、00 mg/kg蛋氨酸螯合锌。试验期为8周,采用3层立体笼养,每周进行称重、称料,通过饲养试验、代谢试验,测定绿头野鸭生长率、耗料量及营养物质的代谢率。研究结果表明,各试验组的平均日增重显著高于对照组(P<0.05),分别提高了12.13%、11.96%,以4~7周效果最明显;能量和蛋白质代谢率均显著高于对照组(P<0.05);料肉比显著低于对照组;从试验的总体效果看,添加75 mg/kg硫酸锌 150 mg/kg蛋氨酸螯合锌效果较好。因此,提倡蛋氨酸螯合锌与硫酸锌混合饲喂绿头野鸭效果好,成本低,建议推广使用。     

不同肠段中氨基酸螯合锌吸收特点的研究

用 50日龄Wistar纯系雄性大鼠 ,以体内原位结扎肠段灌注技术结合放射性同位素示踪技术 ,通过与氯化锌比较 ,研究了十二指肠和空肠对氨基酸螯合锌 (以赖氨酸螯合锌和蛋氨酸螯合锌为代表 )的吸收特点。试验中观察了向结扎肠段灌注含不同形态锌的灌注液后 ,不同时间 (5 ,1 5 ,30 ,60 ,90 ,1 2 0min)血液中6 5Zn比放射性的动态变化 ,1 2 0min (试验结束 )时结扎肠段6 5Zn的消失率 ,不同组织器官中6 5Zn的比放射性的变化。试验结果表明 ,和空肠相比 ,十二指肠对 3种锌源的吸收率高 ;和氯化锌相比 ,十二指肠和空肠对 2种氨基酸螯合锌的吸收率高     

Titanium dioxide photoinduced degradation of some pesticide/fungicide precursors

Five-membered nitrogen heterocycles (pyrrole, imidazole and 1,2,4-triazole) have been degraded using titanium dioxide and simulated solar radiation at pH = 8. The degradations followed a simple Langmuir-Hinshelwood mechanism. Accordingly, the adsorption equilibrium constants K of the heterocycles on the titanium dioxide surface and the rate constants k of degradation of the heterocycle-catalyst adduct have been obtained experimentally. While the K values decrease with heterocycle pKa, the k values increase with increasing pKa. Therefore, apparently, the rate constant depends on the availability of the electron pair on nitrogen, but at the same time the electron pair repulsion induced by the negatively charged titanium dioxide surface at pH = 8 causes a reverse effect in the adsorption equilibrium constant. Only in the case of imidazole, where the adsorption equilibrium constant is low enough (K = 0.013 M(-1)), can the rate constant be approximated to a pseudo-first-order rate expression: k(obs) = Kk. In all other cases, k(obs) = Kk/(1 + K(heterocycle)).     

纳米二氧化钛对纤维素酶活力的影响

作者主要研究不同浓度纳米二氧化钛在不同作用时间、不同温度及不同光照处理条件下对纤维素酶酶活力的影响，以探讨纳米二氧化钛在生物大分子水平上的作用及其作用机理。结果表明：纳米二氧化钛在可见光与紫外光照射条件下均可使纤维素酶失活。而且随着与纤维素酶作用时间的延长、纳米二氧化钛浓度增加和作用温度的升高，其对纤维素酶活力的影响也随之增大。     

氨基酸螯合微量元素在肉鸡生产中的应用研究

选健康的体重近似一致的1日龄艾维茵肉用仔鸡300只。随机分为5个处理，每个处理3个重复：采用单因子设计比较研究复合氨基酸螯合微量元素(Fe、Cu、Mn、Zn)在高铜水平(Cu 250mg／kg)、NRC水平、0．5倍NRC水平、0水平(不添加组)和硫酸盐水平(NRC水平)下对内用仔鸡生产性能、腿病发生率和死亡率的影响。试验结果说明：使用复合氨基酸螯合微量元素时，猪的高铜促生长模式不适用于肉鸡；低水平(0．5倍NRC)使用，有利于发挥复合氨基酸螯合微量元素的营养效应作用。