圈养大熊猫乳中氨基酸组成的研究

为了认识大熊猫乳中氨基酸的组成特点,将大熊猫乳经6 mol/L盐酸水解后,用高效液相色谱测定了不同泌乳阶段的20个乳样的氨基酸组成.结果显示,大熊猫初乳中含量最高的氨基酸是谷氨酸,约为5.2 g/L;常乳和干乳期乳腺分泌物中含量最高的是脯氨酸;总氨基酸含量在泌乳2～10 d内变化不明显,平均值约为34 g/L;干乳期乳中氨基酸含量变化显著.     

大熊猫乳汁蛋白组成

测定了2只大熊猫（ailuropoda melanoleuca)乳汁中蛋白含量,乳糖含量,乳蛋白组成,并与成都麻羊（Capra hircus)初乳和中国荷斯坦牛（Bos taurus)乳进行了比较,大熊猫乳蛋白含量平均为41．52g/L,与中国荷斯坦牛乳接近;乳糖平均含量为15．41g/L,极显著低于牛乳和成都麻羊初乳,乳蛋白SDS－PAGE分析表明,大熊猫乳中酪蛋白（CN）含量明显低于羊乳和牛乳;乳中存在3条蛋白含量的区带,而在成都麻羊和中国荷斯坦牛乳电泳图谱的相应位置未见明显的区带,乳中上皮粘蛋白MUC1仅存在1条分子量约为196kDa的区带,未发现多态现象。     

不同产地藏红花游离氨基酸比较分析

目的：研究不同产地藏红花中游离氨基酸含量，为藏红花的研究、产品设计和开发提供理论支持。方法：以云南维西、上海、西藏、伊朗等地藏红花为实验材料，采用氨基酸自动分析仪对藏红花中游离氨基酸进行了测定。结果：（1）供试样品中除上海样品中检出17种游离氨基酸，其余样品均检出18种氨基酸，各样品中氨基酸总量分别为维西3号样品（编号为W3）981.464(mg/100 g)、维西2号样品（编号为W2）882.646 (mg/100 g)、维西1号样品（编号为W1）785.140 (mg/100 g)、西藏样品（编号为XZ）325.106 (mg/100 g)，上海样品（编号为SH）312.369 (mg/100 g)、伊朗样品（编号为YL）310.427 (mg/100 g);(2)在游离氨基酸中，有赖氨酸、苯丙氨酸、苏氨酸、异亮氨酸、亮氨酸、缬氨酸等6种人体必需氨基酸；有谷氨酸、谷氨酰胺、天冬酰胺和天门冬氨酸等4种鲜味氨基酸；有丝氨酸、甘氨酸和丙氨酸等3种甜味氨基酸；有冬酰胺、天冬氨酸、谷氨酸、甘氨酸、亮氨酸、酪氨酸、赖氨酸、苯丙氨酸、精氨酸等9种药效氨基酸；（3）藏红花游离氨基酸中，丙氨酸含量最...     

不同品种药用菊花中游离糖类及游离氨基酸含量的HPLC分析

为比较不同品种菊花的品质特征,本文采用HPLC法测定其游离糖类及游离氨基酸的含量.结果表明,不同品种菊花中游离糖类主要成分是果糖和葡萄糖,蔗糖和麦芽糖未检出,总游离糖类含量约为9.07～18.76g/1O0g,其中黄山贡菊中含量最高,为18.76g/100g,黄菊中最低,为9.07g/100g;其总游离氨基酸含量约为0.563～2.806g/100g,七月菊中含量最高,为2.806g/100g,杭白菊中最低,为0.563g/100g.     

闽产李果实氨基酸组成及其营养分析

为了弄清不同闽产李（Prunus salicina）果实氨基酸含量、组成及营养价值,采用氨基酸自动分析仪 对不同李果实样品中各种氨基酸的含量进行检测,并对其组成进行比较分析。结果表明,李果实含有18种蛋白质氨基酸和3种非蛋白质氨基酸。田黄李的牛磺酸含量与蛋白质氨基酸含量均最高分别为26.54 mg/100 g和496.14 mg/100 g;皇后李的鸟氨酸、药用氨基酸、酸味氨基酸含量以及特殊功效蛋白质氨基酸的比重均最高分别为0.36 mg/100 g、364.67 mg/100 g、298.28 mg/100 g和73.45%;早熟胭脂李的γ-氨基丁酸含量最高为7.98 mg/100 g;大胭脂李的支链氨基酸含量最高为46.77 mg/100 g。李果实中氨基酸种类齐全、含量存在一定的差异,可根据不同的开发利用目标选择合适的品种。     

富γ-氨基丁酸（GABA）金川发芽红糙米制备工艺研究

γ-氨基丁酸（GABA）是一种天然存在非蛋白质的氨基酸,具有多种特殊的生理功能,在发芽糙米中含量较高。本实验以金川红糙米为原料,以GABA含量为研究对象,通过正交实验得到富集GABA的最佳红糙米发芽工艺条件为：浸泡温度为25 ℃,浸泡时间2 h,发芽时间为48 h,发芽温度40 ℃,CaCl2溶液浓度为1 mg/ml,纤维素酶溶液浓度为0.64 mg/ml,谷氨酸溶液浓度为1.5 mmol/L。此时GABA含量可达到46.3436 mg/100 g,其结果约为发芽前的2倍。     

不同产地和品种桑叶游离氨基酸主成分分析及综合评价CSCD

研究重庆市3个品种共17种不同产地桑叶水提液中游离氨基酸组成及含量,为本地区桑叶的开发利用提供理论基础。以桑、华桑、鸡桑3个品种不同采样地区的样品为原材料,模拟桑叶茶冲泡方式获得水提液,用HPLC荧光法测定其游离氨基酸含量并计算18种游离氨基酸的味道强度值(taste activity value,TAV),通过相关性分析、主成分分析、聚类分析等方法综合评价不同品种和产地桑叶营养成分和风味特征。研究结果显示,不同品种、不同产地桑叶氨基酸种类无明显差别,但氨基酸含量存在差异,可测得最高总氨基酸、必需氨基酸、半必需氨基酸、非必需氨基酸含量分别为1927.33 mg/100g、322.6 mg/100g、46.17 mg/100g和1558.56 mg/100g;桑叶氨基酸风味特征表现为甜味氨基酸>鲜味氨基酸>苦味氨基酸;聚类分析将17个样品分为2类,重庆市巴南区安澜镇鸡桑(S15)、华桑(S7)两个品种的氨基酸品质高。综上所述,桑叶中氨基酸含量丰富,具有较高的营养价值,可开发氨基酸类功能性食品。     

蚯蚓活动对土壤氨基酸组分及含量的影响

通过室内培养试验,研究了赤子爱胜蚓(Eisenia foetida)和威廉环毛蚓(Metaphire guillelmi)对土壤氨基酸组分及含量的影响,并探讨了两种不同生活型蚯蚓作用效果的异同。结果表明:蚯蚓活动可显著改变土壤氨基酸含量,爱胜蚓作用下土壤酸解氨基酸和游离氨基酸分别增加5.08 g/kg和7.72 mg/kg,环毛蚓作用下土壤酸解氨基酸和游离氨基酸分别增加3.86 g/kg和4.44mg/kg。各处理酸解氨基酸均以中性氨基酸所占比例为最大(平均51.9%),酸性氨基酸次之(平均23.3%),而含硫氨基酸(平均14.4%)及碱性氨基酸最少(平均10.4%)。各处理游离氨基酸同样以中性氨基酸为主,平均54.4%,而以碱性氨基酸含量最少,平均仅为7.2%。蚯蚓活动并未改变土壤氨基酸可检出种类,各处理分别检测出16种酸解氨基酸和14种游离氨基酸。土壤酸解氨基酸和游离氨基酸组分含量在蚯蚓作用下均有明显改变:加入爱胜蚓后土壤酸解氨基酸组分中天冬氨酸、精氨酸、甲硫氨酸、丙氨酸、赖氨酸和甘氨酸增幅较高,均在85.7%以上,缬氨酸、苏氨酸、丝氨酸、谷氨酸、亮氨酸、酪氨酸和组氨酸增幅较小在40.7%—62.7%间波动;加入环毛蚓后土壤酸解氨基酸组分中甲硫氨酸、赖氨酸、天冬氨酸、酪氨酸和丙氨酸增幅较大,均在71.9%以上,甘氨酸、精氨酸、异亮氨酸增幅适中,分别为56.8%、55.6%和54.9%;丝氨酸、亮氨酸、苏氨酸、谷氨酸、组氨酸和苯丙氨酸增幅最小,均在40%以下;游离氨基酸组分中组氨酸、精氨酸、甘氨酸、亮氨酸、异亮氨酸和丙氨酸在加入爱胜蚓后增加的幅度较大,增幅在150.0%以上,增幅较为缓和的氨基酸组分有天冬氨酸、苏氨酸、丝氨酸、缬氨酸、谷氨酸和苯丙氨酸,介于58.8%—92.1%之间;环毛蚓作用下,天冬氨酸、精氨酸、丝氨酸和异亮氨酸增幅最大,分别为184.2%、173.3%、163.0%和116.6%;苏氨酸、亮氨酸、缬氨酸和甘氨酸增幅较缓,介于52.3%—92.7%之间;谷氨酸、组氨酸、苯丙氨酸、丙氨酸和甲硫氨酸增幅较低,均在33.1%之下;而半胱氨酸在蚯蚓作用下显著降低,降幅为11.8%。对比两种生活型蚯蚓作用效果可知,土壤氨基酸总含量及各组分含量在爱胜蚓和环毛蚓作用下的增加或减少趋势相同(土壤酸解氨基酸组分缬氨酸除外),但改变幅度却存在明显差异,总体而言,爱胜蚓作用效果优于环毛蚓。     

施用磷对王桉 (Eucalyptus regnans F. Muell.)幼苗生长及其氨基酸组

王桉 (Eucalyptus regnans F. Muell.) 是澳大利亚桉树中最重要的商业用材和人工造林树种之一.研究王桉的施肥与其体内氨基酸的积累和转化及与食叶虫害之间的相关性具有重要的经济和生态意义.在温室内利用2种不同来源的土壤对王桉幼苗进行了不同磷施用量(100 kg hm~(-2)和 200 kg hm~(-2))处理.结果显示,不同土壤和不同磷施用量对苗木生长影响显著,但均未显著影响苗木各部分的氮和磷含量水平.苗木木质部渗出液中的氨基酸含量以谷氨酰胺为主,并与苗木生长和磷施用量呈反相关.不同土壤和磷施用量对苗木组织中游离氨基酸组分和含量的影响不显著,但游离氨基酸的组分和相对水平随叶龄变化明显,尤其是精氨酸在嫩叶氨基酸总量中只占2%～3%,但在老叶中占到20%多;精氨酸在老叶中的积累极有可能是某些蛋白质降解而精氨酸即时合成所致,因为精氨酸一般不在韧皮部转运.谷氨酰胺在树液中含量最高并与苗木生长呈反相关或许可以作为预测桉树发生食叶昆虫危害的一个有用指标.     

Accq.Tag法测定氨基酸口服液的氨基酸含量

采用AccQ .Tag法对氨基酸口服液中游离氨基酸和牛磺酸含量进行了分离测定。产品中氨基酸总量达 85mg/ml以上 ,共 1 3种氨基酸。必需氨基酸与非必需氨基酸比例为 2 .2 0～ 2 .50∶1 ,支 /芳比为 2 .30～ 2 .55∶1 .配方接近于FAO氨基酸比例模式 ,以FAO氨基酸模式及化学评分评价了该制剂的营养价值 ,基本上不存在限制氨基酸 ,化学评分均在 90分以上。     

Concentration of lactoferrin and transferrin throughout lactation in cow's colostrum and milk

The evolution of the concentration of lactoferrin and transferrin was studied in cow's colostrum and milk throughout lactation. The highest concentrations of both proteins were found in the first milking (0.83 mg/ml for lactoferrin and 1.07 mg/ml for transferrin), decreasing sharply during the first days of lactation (colostral period). Thereafter, the concentrations of these proteins decreased slowly, reaching their definitive values during the third week post-partum (0.09 mg/ml for lactoferrin and 0.02 mg/ml for transferrin). The ratio transferrin/albumin in colostrum (first milking), mature milk, milk from mastitic cows and serum was determined, and found to be four times greater in colostrum than in mature or mastitic milk, suggesting a specific transport of transferrin from blood to milk.     

大熊猫生长激素受体(GHR) cDNA 的克隆与序列分析

根据已报道的若干物种GHR 基因cDNA 序列设计引物, 利用RT- PCR 技术首次从大熊猫肝脏组织总RNA中扩增出GHR 基因编码区全长cDNA 序列, 克隆于pGEM®-T 载体后进行测序和序列分析。结果表明,大熊猫GHR 的ORF为1 917 bp , 编码638 个氨基酸的前体蛋白, 由18 个氨基酸的信号肽和620 个氨基酸的成熟肽组成,与人、狗、猪GHR 结构相似, 大熊猫GHR 成熟肽由246 个氨基酸的胞外区、24 个氨基酸的跨膜区和350 个氨基酸的胞内区组成, 并具GHR 的特征性结构。序列相似性比较显示, 大熊猫GHR 与哺乳类GHR 具有69 %～93 %的高序列相似性, 与爬行类和鸟类的序列相似性也达到60 % , 而与鱼类的序列相似性较低, 仅为30 %左右。与其它哺乳动物GHR 相比, 大熊猫GHR 在氨基酸序列上也存在明显的特异性。     

基于高分辨率网络的大熊猫姿态估计方法

对圈养大熊猫 (Ailuropoda melanoleuca) 开展长期行为监测能及时了解其所处生理周期和健康状况,有助于繁殖饲养机构迅速采取相应繁育保护措施提高饲养管理水平,但目前无法对大熊猫进行24 h监控并及时地获得相应的行为信息。准确的动物姿态估计是动物行为研究的关键,也是诸多下游应用的基础。了解大熊猫的姿态可以促进大熊猫行为研究并提升保护管理水平。为了提高复杂环境下大熊猫姿态估计的准确率,本文以高分辨率网络 (High resolution net, HRNet) 为基础网络架构提出了一种大熊猫姿态估计方法：针对大熊猫不同部位尺度差异较大的问题,在HRNet-32中引入了空洞空间金字塔池化 (Atrous spatial pyramid pooling, ASPP) 模块,在提升特征感受野的同时捕获多尺度信息;同时对大熊猫身体关键点进行分组,引入基于部位的多分支结构来学习特定于每个部位组的表征。多次对比实验结果表明本文所用模型具有较高的检测精度：在PCK@0.05中所用模型精度达到了81.51%。本文提出的方法可为大熊猫的行为分析和健康评估提供技术支撑。     

The giant panda is closer to a bear,judged by α- and β-hemoglobin sequences

Summary Using - and -hemoglobin sequences, we made a maximum likelihood inference as to the phylogenetic relationship among carnivores, including the two pandas, giant and lesser. Molecular phylogenetic studies up to 1985 had consistently indicated that the giant panda is more closely related to the bear than to the lesser panda. In 1986, however, a contradictory tree was constructed, using hemoglobins and so on, in which the two pandas link together (Tagle et al. 1986). In contrast to that tree, our conclusion supports the close relationship between bear and giant panda. The surface impression of a close relationship between the two pandas drawn from pairwise amino acid differences is explained by a rapid rate of hemoglobin evolution in the bear compared to that in the two pandas.Offprint requests to: T. Hashimoto     

Ghrelin is present in human colostrum, transitional and mature milk

Ghrelin and its mRNA have recently been found in numerous human tissues including breast. The aim of this study was to compare the ghrelin levels in colostrum, mature and transitional milk and plasma in lactating women with plasma samples from non-lactating women. Venous blood samples were obtained from 17 healthy lactating women aged 22-35 years and from 16 age-matched controls. Colostrum, transitional and mature milk samples were collected just before suckling. The level of bioactive ghrelin was determined by RIA. Comparison of ghrelin values for lactating women showed significantly lower concentrations in colostrum (70.3 +/- 18 pg/ml), transitional milk (83.8 +/- 18pg/ml) and mature milk (97.3 +/- 13 pg/ml) than in the corresponding plasma samples (first day 95 +/- 16 pg/ml, 10th day 111 +/- 13 pg/ml and 15th day 135 +/- 16 pg/ml). The plasma concentrations were lower in the lactating than in the non-lactating women. Thus, the ghrelin levels in colostrum, transitional and mature milk were elavated concomitantly with increasing plasma ghrelin after delivery. The origin of milk ghrelin is not known, but it probably comes from the plasma.     

Lipid composition and vitamin E content in human colostrum and mature milk

Lipidic components, as well as fatty acid composition and vitamin E content were determined in colostrum (days 3-5 of postpartum) and mature milk (day 21) in 8 women from Murcia (Spain). Triglycerides concentration was higher and cholesterol and esterified cholesterol were lower in mature milk than in colostrum, whereas phospholipid content was similar. These differences indicate that the diameter of milk fat globules increases in mature milk. The percentage of medium-chain fatty acids (12:0 and 14:0) increased in mature milk as compared to colostrum, reflecting de novo synthesis of fatty acids. With the only exception of stearic acid which was lower in mature milk than in colostrum, the remaining long-chain fatty acids was similar. The proportion of both linoleic (18:2) and eicosapentaenoic (20:5) acids found in mature milk and colostrum is higher than in studies from other countries and may reflect the intake of high proportions of polyunsaturated fat from vegetable oils and fish in the studied women. Both vitamin E content and vitamin E/linoleic acid ratio in mature milk are lower than in colostrum, evidencing the efficient mechanism of mammary gland vitamin E uptake around parturition.     

圈养大熊猫催产素水平与母性行为之间关系

Maintaining a good cub-rearing relationship is of great significance for the healthy development of newborn giant panda cubs. Oxytocin plays a key role in this cub-rearing relationship development during the breeding period. To investigate the relationship between oxytocin levels and maternal behavior, we sampled the maternal behavior of 6 adult female giant pandas (3 in lactation group, 3 in non-lactation group) at Chengdu Research Base of Giant Panda Breeding from June to September 2019 by using the focal sampling method, and tested the urine oxytocin level of each individuals by using enzyme-linked immunosorbent assay. The results showed that the oxytocin levels were significantly higher in the lactation group (278. 86 pg/mg ±44. 42 pg/mg) than in the non-lactation group. For the two types of breastfeeding groups, the level of oxytocin in the multiparous female pandas (185. 64 pg/mg ±44. 61 pg/mg) was significantly lower than that in the primiparous female pandas (465. 30 pg/mg ±82. 39 pg/mg). Compared with the primiparous female pandas, the multiparous female pandas had more embracing cub behavior (77. 45% ±1. 24%) and feeding behavior (15. 22% ±1. 62%), but less licking cub (14. 26% ±0. 91%) and position adjustment behavior (1. 69% ±0. 29%). Finally, we found the licking cub behavior was significantly positively correlated with the oxytocin level in the lactation group, and the embracing cub behavior was significantly negatively correlated with the oxytocin level in the lactation group. The results indicate that primiparous female pandas show more maternal behavior, less individual behavior and higher oxytocin levels. The results of this study suggest that the different reactions of oxytocin in the two types of giant panda females may help to improve the refined and differentiated breeding techniques for captive giant pandas in the future.     

Free amino acids and protein concentrations in reproductive tract fluids of the mare

Uterine tubal fluids (UTF) were collected daily over a 214-day period (March through August) from three mares. Individual UTF samples identified by day of estrous cycle for five complete cycles within this six-month span were analyzed for free amino acids and total protein. Biochemical comparisons were made to blood plasma by drawing samples daily from each mare. Free amino acids and total protein were determined also on follicular fluids collected from three different mares on days 5 and 6 of standing estrus.The free amino acid level of UTF was significantly greater than was the amino acid concentration in blood plasma or follicular fluid. The highest concentration of amino acids in UTF was on day 13. Cyclic trends were observed for the amino acids, histidine, methionine, half-cystine, serine, proline, glycine, alanine, isolecine, and leucine. Glycine and alanine were found in the highest concentrations in UTF, peaking on day 17 of the estrous cycle. Protein concentration in UTF was highest on day 13 and lowest on days 7 and 19. Protein values for diestrus (33.1 mg/ml) were significantly greater (p<0.05) than for estrus (28.0 mg/ml).