西瓜可溶性固形物含量近红外透射检测技术

设计的近红外透射式西瓜可溶性固形物含量（SSC）检测系统主要包括光纤光谱仪、光纤透射附件、数据采集卡以及自制光源。对50个麒麟瓜SSC进行了预测试验,采用主成分回归和偏最小二乘回归法分别建立了样品的原始光谱、一阶微分光谱、二阶微分光谱和SSC的预测模型,结果表明偏最小二乘回归法建立的模型具有较高的相关性,相关系数为0．951,均方根校正误差0．347,均方根预测误差0．302,样本真实值与预测值的相关系数为0．910。     

不同杀菌工艺对延长货架期牛乳品质的影响

比较传统高温热杀菌、蒸汽浸入式杀菌、膜过滤结合巴氏杀菌对延长货架期牛乳品质的影响,测定不同热处理工艺对微生物指标、货架期、活性物质乳铁蛋白和免疫球蛋白G(immunoglobulin G,IgG)损失率及糠氨酸含量的影响,并优化蒸汽浸入式杀菌、膜过滤结合巴氏杀菌的工艺参数。结果表明：与传统高温杀菌工艺比较,蒸汽浸入式杀菌（147℃、0.09 s）产品货架期更长,品质更稳定,杀菌后糠氨酸含量较低且保留少量的活性物质;膜过滤结合72℃、15 s杀菌能更好地保留活性物质乳铁蛋白和IgG,但是该工艺对贮藏温度要求较高,全程贮藏温度需低于6℃,才能够确保产品在货架期内的品质稳定。     

Variation in the storage proteins of peas in relation to sulphur amino-acid content

Summary A cellulose acetate electrophoretic technique has been used to characterise the storage proteins present in pea seeds in order to try and determine the proportions of proteins present which are enriched in sulphur amino-acids. Some of the eight varieties examined were shown to differ in their proportions of the various storage proteins. When the proteins were separated and estimated quantitatively and also characterised by their sub-unit composition, it was shown that cellulose acetate electrophoresis of crude protein extracts or of whole globulins did not give the degree of resolution required. The procedures which have to be undertaken in order to obtain this information are considered, and the difficulties of incorporating them into a plant breeding programme discussed.     

Effects of ophthalmic disease on concentrations of plasma fibrinogen and serum amyloid A in the horse

Reasons for performing study: There is little scientific information available about the ability of ocular disease to cause a systemic inflammatory response. Horses are frequently affected with ocular disease and ensuring their systemic health prior to performing vision saving surgery under anaesthesia is essential for the successful treatment of ophthalmic disease. Hypothesis: Ocular disease will cause elevations in the concentration of the acute phase proteins fibrinogen and serum amyloid A in peripheral blood. Methods: Whole blood and serum samples were obtained from 38 mature horses with ulcerative keratitis or uveitis and no evidence of systemic disease, 9 mature horses with no evidence of ocular or systemic disease (negative controls) and 10 mature horses with systemic inflammatory disease and no evidence of ocular disease (positive controls). Blood samples were assayed for concentrations of the acute phase proteins fibrinogen and serum amyloid A. Results: Fibrinogen and serum amyloid A were significantly different in the positive control group compared to the negative control, corneal disease and uveitis groups (P<0.126). There was no significant difference between the negative control, corneal disease and uveitis groups (P<0.001). Conclusions: Ulcerative keratitis and anterior uveitis are not associated with elevated concentrations of the acute phase proteins fibrinogen and serum amyloid A in peripheral blood. Potential relevance: When the clinician is presented with a patient with ocular disease and elevated plasma fibrinogen or serum amyloid A concentrations, a nonocular inflammatory focus should be suspected.     

Low‐density lipoproteins and milk serum proteins improve the quality of stallion sperm after vitrification in straws

Lipids and proteins can be used for sperm vitrification to preserve the integrity of sperm membranes or to increase the viscosity of the medium. This study evaluated the effect of low‐density lipoproteins (LDL) and milk serum proteins (Pronexcell) for stallion sperm vitrification. Hippex extender (Barex Biochemical Products, The Netherlands), plus 1% of bovine serum albumin and 100 mM of trehalose, was used as control for sperm vitrification. In experiment 1, different concentrations of LDL (L1 = 0.25, L2 = 0.5, L3 = 1%) and in experiment 2 of Pronexcell (P1 = 1, P2 = 5, P3 = 10%) were added to control extender. Vitrification was performed in 0.25‐ml straws directly plunged into liquid nitrogen. Total motility (TM, %) and progressive motility (PM, %) were analysed by CASA, and plasma membrane (IMS, %) and acrosome membrane integrity (AIS, %) were assessed under epifluorescence microscopy. Post‐warmed sperm parameters were compared between treatments by ANOVA. Results were expressed as mean ± SEM. In both experiments, the minimum concentration of LDL and Pronexcell obtained significantly higher values (p < 0.01) than the control extender for TM (L1 = 52.95 ± 4.4; P1 = 58.99 ± 4.6; C = 30.88 ± 3.0), PM (L1 = 36.79 ± 5.5; P1 = 47.25 ± 4.3; C = 19.20 ± 2.4), IMS (L1 = 68.88 ± 3.6; P1 = 47.25 ± 4.3; C = 52.81 ± 2.6) and AIS (L1 = 45.88 ± 3.6; P1 = 47.25 ± 4.3; C = 26.00 ± 2.1). No differences in sperm parameters were found among different concentrations of LDL or Pronexcell. In conclusion, the addition of 0.25% LDL and 1% Pronexcell to the vitrification extender is recommended to improve the quality of stallion sperm after vitrification.     

桑树树液蛋白质的双向电泳分析

应用 Ｉ Ｅ Ｆ 和 Ｓ Ｄ Ｓ Ｐ Ａ Ｇ Ｅ 双向电泳技术,分析了桑树（ Ｍｏｒｕｓ） 树液蛋白质的电泳图谱。结果表明,供试栽培品种的蛋白质谱比较相似,相似系数在０７２ ～１００ 之间;品种间存在１４ 个共有组分,占检测组分总数的５１９ ％ ;桑树栽培种与野生种的差异比较显著。     

圆叶决明添加量对红壤可溶性氮及酶活性的影响

为了探明圆叶决明(Chamaecrista rotundifolia)降解后红壤可溶性氮及氮水解酶活性的变化规律,本研究采用室内好气恒湿培养法,研究占红壤质量0.5%(T1),1%(T2)和2%(T3)的圆叶决明添加至红壤中,培养7~88d内红壤硝态氮(NO^-₃-N)、铵态氮(NH⁺₄-N)和可溶性有机氮(Soluble organic nitrogen,SON)及脲酶、蛋白酶和天冬酰胺酶的变化。结果表明：添加圆叶决明后,红壤NO^-₃-N和NH⁺₄-N含量在培养前期降低,培养中期增加;而整个培养期SON含量及脲酶、蛋白酶和天冬酰胺酶活性均增加,且圆叶决明添加量越大,效果越显著。NO^-₃-N和SON含量及脲酶、蛋白酶和天冬酰胺酶活性可用2次或3次函数方程拟合;而NH⁺₄-N含量可用线性函数拟合。氮水解酶与NO^-₃-N负相关,与NH⁺₄-N和SON正相关,且相关性从大到小的顺序为蛋白酶>天冬酰胺酶>脲酶。综上,添加圆叶决明提高了红壤供氮水平和红壤氮转化能力。     

Exogenous testosterone modulates tumor necrosis factor-alpha and acute phase protein responses to repeated endotoxin challenge in steers

Clinical responses to some disease agents differ between sexes and this dimorphism has been attributed to the immunomodulating effects of steroid hormones. Our objective was to determine in steers the effect of testosterone on circulating concentrations of immune response mediators (tumor necrosis factor-alpha, TNF-alpha; serum amyloid-A, SAA; haptoglobin, HG; xanthine oxidase, XO; nitric oxide, NO) after two consecutive endotoxin challenges (LPS1 and LPS2, 5 days apart; 0.25 microg/kg BW). Sixteen crossbred steers (328+/-6 kg) were assigned to control (CON, n=8) or testosterone cypionate treatment (TES, n=8; 100 mg/m2 body surface; i.m. injection 12 and 2 days before LPS1). The response to LPS was calculated as area under the timexconcentration curve (AUC) for the parameter measured. After LPS1, TNF-alpha AUC was greater in TES than CON (P<0.05). Plasma HG and SAA concentrations increased (P<0.01) after LPS1 and LPS2. In all steers SAA AUC was greater after LPS1 than LPS2 (P<0.01) but the response was augmented over CON with testosterone treatment (P<0.05). HG response to LPS1 within 24 h was not affected by testosterone. However, 5 days after LPS1 mean plasma HG concentration remained higher in TES than CON (P<0.01). HG response to LPS2 was greater in TES than CON (P<0.01). Plasma nitrate+nitrite concentration (NO production marker) and XO activity increased after each LPS challenge but responses were not affected by testosterone treatment. Results indicate that the presence of circulating testosterone increases the magnitude of the TNF-alpha response to LPS challenge as well as the subsequent increases in acute phase proteins (APP). Effects of testosterone on increases in TNF-alpha and APP may underlie a differential presentation of disease symptoms between sexes or between steers and bulls. The data also suggest a role for testosterone in the development of tolerance to repeated immune challenge through its effect on the increased magnitude and duration of HG response.     

补料及开食料中不同种类蛋白质对仔猪过敏反应及腹泻程度的影响

用３周龄断奶仔猪研究了补料和开食料中不同蛋白料对断奶后的过敏反应和腹泻程度的影响、补饲和开食料中分别以玉米－豆饼、豆饼、醇处理豆饼或乳蛋白为唯一蛋白来源的补料。仔猪７日龄开始补饲，试验至３５日龄结束。结果表明，断奶后保持蛋白来源不变时仔猪的过敏和腹泻程度比改用复合开食料时低，木糖吸收和养分消化率高（Ｐ＜０．０１），但补豆饼组例外；乳蛋白引起的过敏反应最弱，腹泻程度最低，木糖吸收率和养分消化率最高，豆饼引起的腹泻最严重，腹泻开始最早，持续时间最长，木糖吸收率和养分消化率最低，玉米－豆饼和醇处理豆饼引起的腹泻程度居中（Ｐ＜０．０５）；断奶各组３５日龄木糖吸收率极显著高于２８ｍ日龄吸收率（Ｐ＜０．０１），但低于不断奶的对照组相应值（Ｐ＜０．０１）。粪中大肠杆菌计数表明，腹泻程度与微生物增殖无关。由此认为，肠道对日粮抗原过敏是仔猪断奶后腹泻的主要原因；过敏和耐受程度及补饲约影响取决于日粮蛋白质种类。