Development of X-ray computed tomography for live standing cattle

An X‐ray computed tomography (CT) system for live standing cattle was developed for studying the meat yield, carcass composition and so on. The gantry contained three X‐ray tubes and detectors that corresponded to each X‐ray tube. The system was able to operate while the animal remained standing. The scan area had a diameter of 900 mm. The Musculus longissimus and Musculus trapezius areas, and the back fat thickness in the CT image were evaluated and compared to the actual cross‐section of the carcass using eight cattle. The differences among the muscles, and the subcutaneous and intermuscular fat were easily recognized. The correlation coefficient between the CT image and the actual carcass photograph of the M. longissimus area and the back fat thickness was high (r = 0.84, r = 0.93, P < 0.01). The present study demonstrated that muscle, fat and bone can be clearly imaged from a live standing animal using X‐ray equipment.     

三唑酮种衣剂对小麦白粉菌侵染和非侵染位点硅等元素含量的影响

 借助扫描电子显微镜-X射线能谱分析方法从超微结构和元素水平观测了三唑酮种衣剂包衣处理和空白对照的小麦幼苗上白粉病菌侵染及非侵染位点硅等元素含量的变化。结果表明,接种后20~36 h内三唑酮种衣剂处理的麦苗侵染位点细胞内元素硅含量由5.204%上升为42.064%,非侵染位点由5.821%上升为12.342%;空白对照中侵染位点元素硅含量由低于检测水平上升为17.388%,非侵染位点接种后36 h时为19.460%。在处理和空白对照的麦苗上侵染和非侵染位点均检测到了含量不等的磷、硫、氯等元素存在。     

驱除瘤胃真菌对绵羊瘤胃内纤维物质降解的影响

选取3只体况良好,带有永久性瘤胃瘘管的蒙古羊与小尾寒羊的杂交一代公羊,运用尼龙袋法研究全部驱除瘤胃真菌对绵羊瘤胃内稻草纤维物质降解的影响.结果表明：全部驱除瘤胃厌氧真菌后,改变了瘤胃内纤维物质的降解动力学参数,显著降低了瘤胃内稻草DM、NDF、ADF的降解速率（P＜0.05）,显著提高了三者的消化延滞时间（P＜0.05）,显著降低了稻草NDF、ADF的降解率,而DM的降解率有所降低,但差异不显著（P＞0.05）.说明瘤胃真菌在纤维物质降解中发挥了重要的作用.     

Dietary fibre and indigestible protein increase ileal glycoprotein output without impacting colonic crypt goblet cells in weaned piglets

Mucus plays an important role in gut health by favouring colonisation resistance. The aim of this study was to quantify the impact of fibre and protein on mucin recovery in ileal digesta and on goblet cell histochemistry in the proximal colon. A control diet with highly digestible protein and low fibre and three complex diets containing indigestible protein associated with low, soluble or insoluble fibre sources were tested for 14 days in piglets weaned at 28 days of age. Mucin concentration was determined by ethanol precipitation. Goblet cell subtypes in colonic crypts were analysed by histochemistry. The ileal mucin output was higher with the complex diets than with the control diet (31.6 on average vs 21.7 g/kg DM intake). Increases observed with the low and soluble fibre diets were similar (34 g/kg DM intake). This suggests a limited effect of soluble fibre in presence of indigestible protein. Surprisingly, the observed increase was lower with insoluble fibre (27.2 g/kg DM intake). DM and N output and digestibility were not affected by the diets, but a linear relationship was found between DM and mucin output. In proximal colon, crypt depth, goblet cell numbers per crypt and glycosylation subtypes were not affected by the diet suggesting no change in the capacity of mucus to protect the gut. To conclude, introducing highly indigestible protein in the diet increased ileal mucin output, without effects of these factors on crypt goblet cell patterns in the proximal colon. Introducing fibre in a diet containing highly indigestible protein had a marginal effect.     

光照对棉花胚珠纤维离体发育的影响

分析了光照和黑暗条件下，对培养棉花胚珠纤维离体发育的影响。表明在其它条件相同时，纤维离体发育在基因型之间有很大的差异，光照对纤维的发育起了明显的抑制作用。无论受精胚珠还是未受精胚珠，在光照条件下其胚珠成活率、纤维诱导率、纤维生长量、胚珠鲜重均低于在黑暗条件。尤其是未受精胚珠，在光照条件下珂３１２ 与ＴＭ－ １虽能诱导产生纤维，但纤维诱导率很低，仅有８．１９％ 和４．９６％ ，纤维生长量为０．１６３７和０．１１３２，而浙５０６、罗甸铁子和徐州１４２无絮突变体均不能产生纤维。本试验表明：只有在黑暗条件下才适合纤维离体发育。     

预氧丝原位炭化无粘结剂C/C复合材料氧化动力学研究

采用恒温热重法测定了在空气中，０．１ＭＰａ，６７３Ｋ到９７３Ｋ下预氧丝（即预氧化聚丙烯腈纤维）原位炭化无粘结剂Ｃ／Ｃ复合的氧化失重率；并利用扫描电镜分析了这种复合材料氧化前后的结构，氧化动力学测定结果表明：该材料在氧化开始时，其氧化速率随时间的增长而增大，然后随时间的延长而减小，并趋向恒定，研究表明：该材料中预氧丝与基体炭界面结合处是空气中氧的扩散通道，杂质为空气中氧的吸附起到了有附活性中心的催化     

德系安格拉毛用兔日粮最适营养水平探讨

本试验选用德系安格拉成年毛用兔80只,研究了其日粮不同粗蛋白(CP)、含硫氨基酸(SAA)和粗纤维(CF)水平对产毛性能的影响。结果表明,日粮中CP水平以16%～18%为宜,过高的CP水平并不能提高产毛率和毛的质量;日粮中SAA水平以0.65%～0.85%为宜,日粮配方中添加一定量的蛋氨酸能显著提高产毛性能;日粮中CF水平以14%左右提高毛的产量和质量为最佳,过精的日粮不仅造成浪费,而且对产毛性能并没有好处。     

Research on Magnetic Activated Carbon by XPS

DIntroduction'Asonekindofimportantedbent,activatedcarbo11wasusedinlnoreandl11orefieIds.MagneticactivatedcarbonisbecoIninganinterestil1gsubjectfOrsoIvi11gseparationofactivatedcarbo11i11thisfieId.Mag11eticactivatedcarbol1wl1ichusemagneticreagentandacti-vatedcarbonasrawmateriaIl1asmal1yadva11tagesl'Isuchasgiantspecificsurface'weII-distributiOI1al1d firmly-combined1nagl1e1ism.ButtI1eadsorptivemechanismoftl1emagneticreage11tol1activatedcarbonisstiIIunknown.X-rayphotoelectronpectroscopy(X…     

X射线在防腐木材有效成分测定中的应用

采用X射线荧光光谱仪与原子吸收分光光度计,分别测定铬化砷酸铜(CCA)以及氨/胺溶铜季胺盐(ACQ)处理木材中活性成分的含量,并将两者的结果进行了比较和分析。结果表明,用这2种方法所测得的结果差异较小,但前者具备检测速度快、分析精度高、操作简便等优点,可在实际应用中推广。