不同季节大曲生产过程中真菌群落结构的演变

采用高通量测序技术和多元统计方法,对比研究夏秋两季高温大曲生产过程中的真菌群落结构及其演变。结果表明,夏季大曲的主要真菌有14个属,秋季大曲有17个属,且夏季大曲的主要真菌在秋季大曲中均存在;Pichia、Saccharomycopsis和Wickerhamomyces是夏秋两季大曲生产起始的主要真菌,其中Pichia是秋季大曲生产全程的主要真菌类群,Thermoascus是夏季大曲发酵后期的优势真菌类群;秋季大曲生产过程中真菌类群数量更多,而夏季大曲真菌物种分布更均匀;夏秋两季大曲生产过程可分为2个阶段,分别以8d和12d为分界线,秋季大曲生产过程更易受外界条件影响,特别是生产前期。     

国产烤烟挥发碱含量对比分析

测定了全国6个省2002和2003年的170个烤烟烟叶样品的挥发碱含量。结果表明:①各产区各等级烟叶挥发碱含量集中在0.10%~0.45%范围内;②相同等级不同产区烟叶挥发碱含量以云南弥勒的最高,贵州毕节和四川会理的较高,福建和山东临沂的较低,河南宜阳的最低,各产区烟叶的挥发碱含量差异显著;③不同部位烟叶挥发碱含量是下部叶最低,中部叶次之,上部叶最高,而且上部叶比下部叶高2倍左右,挥发碱含量差异极显著;④各产区相同部位桔黄颜色烟叶的挥发碱含量均高于柠檬黄,烟叶挥发碱含量差异极显著;⑤烟叶挥发碱含量随其身份由薄到厚、油份由少到多和色度由淡到浓均逐渐增加,差异都极显著。     

Fatty acid composition of grain from winter and spring sown oats, barley and wheat.

The fatty acid composition of grain has been studied in six varieties of oats, two of wheat and two of barley, sown in pots in an unheated glasshouse in winter and in spring. Differences were found between the species in composition and in their response to sowing date. Oats showed the greatest varietal variation in both total fatty acid (TFA) content and in the proportion of its component fatty acids. The content and degree of unsaturation of the oat TFA was higher in the winter sown than in the spring sown crop. Increases in the TFA content of oats, whether arising from differences in variety or sowing date, were generally followed by an increase in the proportion of oleic acid and a decrease in the proportions of palmitic and linoleic acid in the TFA. Winter sowing, as compared with spring, led to a small, but significant, decrease in the TFA content of barley and an increase in its degree of unsaturation. There were no significant changes in the content or composition of wheat TFA as a result of differences in sowing date. Factors influencing the differences in TFA content and composition between species, varieties and sowing dates are discussed.     

棉纺细纱后区牵伸型式的演变与发展(三)

为说明后区牵伸运用原则,从后区牵伸中纱条紧密度测定、有捻粗纱的匀伸作用、牵伸力与输出纱条不匀关系测定、不同牵伸分配、不同粗纱捻系数下前区牵伸力测定等方面分析,指出后区牵伸为前区主牵伸创造良好的牵伸条件;其实质是使喂入前区的牵伸纱条具有较均匀结构和必要紧密度,它产生的内摩擦力场强度与前区外摩擦力场强度分布相配合,共同形成胶圈牵伸良好而稳定的总摩擦力场强度分布,有利于成纱质量的提高;表明在此前提下,后区适当承担总牵伸的一部分可以减轻前区牵伸过大的负担,这就是后区牵伸运用原则。对罗拉直线牵伸、罗拉曲线牵伸和胶圈牵伸等各种后区牵伸型式进行了摩擦力场强度分布分析比较,指出单控制辊式VC型曲线牵伸是后区牵伸型式的重大突破和发展,可发挥前、后区牵伸潜力,其总牵伸能力达50倍～150倍,成为第三代大牵伸新水平,是后区牵伸型式技术进步的标志。     

Evaluation of arterial digital blood flow in dairy cows with claw horn disruption lesions using Doppler ultrasonography

Vascular changes play an important role in the pathogenesis of claw horn disruption lesions in cattle. The aim of the study was to measure arterial blood flow in the hind limbs of German Holstein cows with claw horn disruption lesions. A 10-MHz linear transducer was used to assess blood flow in the interdigital artery in the dorsal pastern region in the hind limbs of 11 non-lame and 33 lame German Holstein cows in which lameness was scored clinically. Qualitative and quantitative blood flow parameters were compared in affected limbs and unaffected contralateral hind limbs in lame cows and in the hind limbs of lame cows and non-lame cows. A pulsed-wave Doppler signal suitable for analysis was obtained in 78 of 88 limbs (33 affected and contralateral limbs, 22 limbs of control cows). Blood flow curve types 1 and 2 were predominant in the hind limbs of lame cows. Vessel diameter, end-diastolic velocity, and blood flow rate were significantly greater in lame cows than in non-lame cows and were numerically greater in moderately lame cows than in mildly lame cows. The differences in the qualitative and quantitative parameters between lame and non-lame cows were most likely caused by inflammation of the pododerm. The role of weight distribution between the paired hind limbs and the existence of claw horn disruption appeared to have an effect on the differences in local circulation in the affected and unaffected contralateral hind limbs in lame cows.     

毛竹笋持久性有机污染物分布特征

以浙江省毛竹笋为对象,研究不同部位、不同季节和不同区域的毛竹笋中21 种有机氯、18 种多氯联苯和16 种多环芳烃三类持久性有机污染物的分布特征。结果表明：有机氯在笋肉中分布高于笋壳,笋肉上部高于下部,春笋污染为冬笋的4 倍,污染较重地区为上虞,含量最高的为毒杀芬（约105 μg/kg）。多氯联苯在笋肉中分布高于笋壳,笋肉下部高于上部,春笋污染高于冬笋,污染较重地区为武义,含量最高的为PCB52（1.14 μg/kg）;多环芳烃在笋肉和笋壳中分布接近,笋肉上部略高于下部,春笋污染为冬笋的1.5 倍,污染较重地区为永嘉,含量较高的为菲（5.85 μg/kg）。参照现有的限量标准,毛竹笋中55 种持久性有机污染物未超标,处于相对安全水平。研究结果不仅完善了竹笋的质量安全理论基础,也为环境污染的修复治理提供相应的参考。     

Effects of duration of moderate increases in grain feeding on endotoxins in the digestive tract and acute phase proteins in peripheral blood of yearling calves

Effects of duration of grain feeding on the concentration of endotoxic lipopolysaccharide (LPS) in digesta throughout the digestive tract and on acute phase proteins and LPS in peripheral blood were determined in Holstein yearling calves. Twenty-five Holstein yearling steer calves received either a forage-based diet containing 92% hay and 8% of a mineral and vitamin pellet on a dry matter basis (CON) or a moderate-grain diet, obtained by replacing 41.5% of the hay in the forage-based diet with barley grain, for 3 (MG3), 7 (MG7), 14 (MG14), or 21 d (MG21) before slaughter. Immediately before slaughter, blood samples were collected from the jugular vein. Immediately after slaughter, digesta samples were collected from the rumen, jejunum, ileum, cecum, colon, and rectum. Rumen liquid digesta, digesta from the intestines, and peripheral blood plasma were analyzed for LPS. Peripheral blood plasma and serum were analyzed for the acute phase proteins amyloid A, haptoglobin, and LPS-binding protein. Feeding the grain diet increased the LPS concentration in rumen fluid linearly from 15,488 endotoxin units (EU)/mL for CON to 70,146 EU/mL for MG7. Concentrations of LPS in rumen fluid in MG14 and MG21 were 61,944 and 56,234 EU/mL, respectively, and did not differ. The LPS concentrations in jejunal digesta were much lower than that in digesta elsewhere in the digestive tract, which suggests that ruminal LPS is broken down in the abomasum or proximal jejunum. The concentration of digesta LPS in the ileum was higher than that of digesta elsewhere in the intestines and similar to that in rumen fluid. The duration of grain feeding increased the LPS concentration in digesta in the ileum and cecum and tended to increase that in the colon cubically. Concentrations of LPS in this part of the digestive tract were highest in the MG3 and MG21 groups. The highest concentrations of LPS in digesta in the cecum, colon, and rectum were 3.7, 3.8, and 5.6 times higher than that in CON, respectively. Grain feeding and the increase in LPS in digesta were not accompanied by an acute phase response or a detectable concentration of LPS in peripheral blood. The absence of LPS in peripheral blood and the lack of increase in acute phase proteins indicated that the grain feeding protocol used in the current study and the accompanying changes in LPS concentrations of the digesta did not result in systemic inflammation.     

The effect of storage on the proteins of frozen liquid egg and spray-dried egg

Storage of spray-dried whole egg and egg-milk mixture for about a year at 3–5°C resulted, in both cases, in a marked reduction in the proportion of insoluble proteins and an equally marked increase in the inert lipoprotein fraction of the soluble proteins; this fraction was clearly derived from the low density fraction of the yolk. Storage of frozen liquid egg for about a year in the frozen state resulted in the insoluble protein fraction of the thawed egg having more water bound in it than did the corresponding fraction of the freshly-frozen egg, but in neither case did the insoluble proteins have as much water bound with them as those of the reconstituted spray-dried samples. Spray-drying results in only a partial reduction in the contents of ovalbumin, ovomucoid and conalbumin, and addition of milk to the whole egg before spray-drying improves the stability of these proteins. They appear to be little changed by freezing and storing in the frozen state. There is evidence that ovalbumin is present in a more stable form in processed egg products than in new-laid raw egg.     

Effect of iodine deficiency on the growth and formation of the bone tissue

The authors studied several groups of children in terms of the height in endemic goiter regions and in the regions with no goiter incidence. Subject to study were also processes of osteogenesis and phosphocalcium metabolism in animals with iodine deficiency in the diet. It was established that in goiter endemic regions, the number of children under medium and of low height was increased while that of medium and over medium height, and the number of tall children were reduced. It was also found that iodine deficiency in the diet of animals entailed abnormalities in the growth patterns, destructive alterations in the bones and bone marrow, a decrease in the content of hydroxyproline, hexosamines, and in the activity of phosphomonoesterase-I in animal bones, as well as disorders of phosphocalcium metabolism.     

Dioxins,furans, and non-ortho PCBs in Canadian Arctic seabirds

This is the first account of PCDDs, PCDFs, and non-ortho PCBs in Canadian Arctic seabirds. Livers and eggs of thick-billed murres, northern fulmars, and black-legged kittiwakes were collected in 1975 and 1993 from Prince Leopold Island in Lancaster Sound, Canada. Detectable concentrations of PCDDs, PCDFs, and non-ortho PCBs were found in all the Arctic seabird samples analyzed. Of the PCDD congeners assayed, only 2,3,7,8-substituted PCDDs were detected in the samples, whereas non-2,3,7,8-substituted PCDFs were found in addition to 2,3,7,8-substituted PCDFs in some of the samples. The predominant PCDD/F congener found in the livers of all three species was 2,3,4,7,8-PnCDF, both in 1975 and 1993. Concentrations of most dioxins and furans decreased in the fulmars and kittiwakes between 1975 and 1993 but increased in the murres. Of the non-ortho PCBs measured, PCB-126 occurred in the highest concentrations and contributed the majority of the non-ortho PCB-TEQ in all three species in both years. The highest concentrations of dioxins and furans as well as the highest TEQ values were found in the northern fulmar livers in both 1975 and 1993. Concentrations of some of the PCDDs and PCDFs are among the highest reported for Canadian Arctic biota.