排序方式： 共有43条查询结果，搜索用时 15 毫秒
31.
利用美国近年研究并应用于实践的博达R牛奶测试技术对太原某牛场奶牛隐性乳房炎进行监测,试验显示,博达R牛奶测试技术方法简便快捷、测定数据准确,具有较大推广应用价值;牛场奶牛隐性乳房炎头阳性率为55.5%(111/200),乳区阳性率为26.34%(196/744);3胎及以上奶牛阳性率达到70.18%(40/57)并显著高于1-2胎35.42%(17/48)(P<0.01);奶牛个体混合乳样体细胞与个体乳区乳样体细胞平均数呈直线相关,差异极显著(r=0.7418,t>t0.01,P<0.01)。 相似文献
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Parboiling involves soaking, steaming, and drying, and soaking is important in achieving desired parboiled rice properties. This study investigated the effects of soaking temperature and commingling on rice properties prior to steaming. Rough rice of four cultivars (Taggart, CL151, XL753, and CL XL745) and their combinations at 1:1 wt ratio were soaked at 65, 70 or 75 °C for 3 h, and dried. Both soaking temperature and difference in onset gelatinization temperature (To) of individual cultivars in commingled rice affected milling and physicochemical properties. The head brown rice yield was greater when the soaking temperature was below but close to the To for individual rice cultivars, but became difficult to predict for commingled rice. Commingled rice consisting of high To rice cultivars required higher soaking temperatures to reduce chalkiness during soaking. The color attributes of commingled rice was predominately affected by the cultivar that exhibited the most change. The gelatinization properties were governed by the low-To cultivar, whereas the pasting properties were more influenced by the high-To cultivar for the commingled rice. Therefore, using commingled rice with a wide range of gelatinization temperature as a feedstock may lead to inconsistent quality of parboiled rice. 相似文献
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十大功劳白粉病发生规律与防治方法研究 总被引：1，自引：0，他引：1
十大功劳白粉病是近年来合肥地区危害较为严重的一种真菌性病害。通过对十大功劳抽梢时间、白粉病发生时间以及与温湿度之间的关系进行研究,并利用5种农药在不同时间进行防治试验,结果表明：十大功劳抽梢时间在3月下旬（5月30日）,白粉病发生于4月中旬（4月18日）;抽梢时日平均气温为15．5℃,病害发生时日平均温度在18℃左右。通过0．05与0．01水平上的方差分析,可以看出：发病前防治效果明显优于发病后防治;3种药剂防治效果以15％粉锈宁1500倍防治效果最好,1％等量式波尔多液次之,50％多菌灵1500倍防效最差。 相似文献
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Native and moistened wheat flours (moisture contents were 13.5 and 27.0%, respectively) were treated with superheated steam (SS) at different temperatures (140 and 170 °C) and times (1, 2 and 4 min). Their physicochemical and digestive properties were analyzed. For native flour, SS treatment altered the starch molecular structure and behavior slightly. While for moistened flour, crystalline degree, gelatinization enthalpy, amylose leaching (AML) and falling number significantly decreased, but thermal transition temperatures increased with the rise of treating severity. Clumping of starch granules, aggregation of proteins and formation of amylose-lipid complexes occurred in both native and moistened flours. Broader pasting temperature ranges and higher viscosities were found on SS-modified flours. Additionally, SS treatment on moistened flours increased resistant and slowly digestible starch contents. In general, SS treatment induced changes in starch molecular structure and reactions among flour components leading to more stable structures, thus affecting their pasting behavior, thermal properties and in vitro digestion. 相似文献
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The objective of this work was to evaluate the changes in the thermal and structural properties of maize starch during nixtamalization and the tortilla-making process and their relationship with grain hardness. Three maize types with varying hardness (hard, intermediate, soft) were processed by three nixtamalization processes (classic, traditional and ecological). Starch from the three maize types showed an A-type pattern and two endotherms corresponding to gelatinization and melting of the Type I amylose-lipid complexes. After cooking and steeping, in intermediate and soft grains the partial gelatinization and the annealing affected the starch properties and promoted the formation of amylose-lipid complexes. These effects were not observe in hard grains. The increase in melting enthalpy and the intensity of the peak 2θ∼20° from nixtamal to tortillas demonstrated the formation of amylose-lipid complexes. A third endotherm above 114 °C in some treatments of nixtamal and tortilla starch demonstrated the transformation of some amylose-lipid complexes in a most ordered structures (Type II complexes). The V-type polymorph structure found in native starch, nixtamal, and tortilla corresponds to a coexistence of Type I and Type II complexes. Formation of amylose-lipid complexes in tortillas had a partial effect on decreasing starch retrogradation (r = −0.47, P < 0.05). 相似文献
36.
G蛋白偶联受体GPR54是新发现的视黄酸家族成员之一,Kisspeptins是其内源性配体,两者均是动物体内的肽类物质,其在不同动物体内的分布区域有差异,但均与青春期启动密切相关。试验证明猪GPR54基因与下丘脑、垂体、卵巢发育性表达有关,GPR54系统在斜带石斑鱼性逆转过程中发挥作用,大鼠GPR54突变者性发育低下等。GPR54/Kisspeptins在调节动物体内促性腺激素LH和FSH的释放、促进生殖器官的发育及青春期启动中均具有重要的作用。 相似文献
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目的 建立“肾虚肝郁证”迟发性性腺功能减退症（Late onset hypogonadism,LOH）动物模型,并对其进行评价。方法 以中医理论“房劳过度伤肾”、“郁久伤肝”为指导,采用“退役种鼠（40周龄）+复合情志刺激+孤养”方法,建立“肾虚肝郁证”LOH动物模型,与正常组（8周龄）比较,以血清总睾酮、悬尾实验、睾丸间质细胞超微结构、睾酮合成相关酶以及Caspase-3 mRNA和蛋白表达为指标。结果 模型组大鼠出现一系列典型的LOH精神、心理、体能改变,与正常组比较,模型组大鼠血清总睾酮水平明显降低,悬尾不动时间显著延长,睾丸组织Caspase-3 mRNA和蛋白表达增强,睾酮合成相关酶类固醇激素合成急性调节蛋白（Steroidogenic Acute Regulatory Protein,StAR）[13]、细胞色素胆固醇侧链裂解酶（Cytochrome P450 side-chain cleavage,P450scc）[14]、3β-羟甾脱氢酶（3beta-hydroxysteroid dehydrogenase,3β-HSD）mRNA和蛋白表达下降,差异均有统计学意义（P<0.01）;模型组睾丸间质变少,睾丸间质细胞线粒体数量减少,出现水肿,线粒体嵴消失。结论 “退役种鼠+复合情志刺激+孤养”方法复制“肾虚肝郁证”LOH模型切实可行,有较高的实用价值。 相似文献
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天然高分子多肽衍生物Jag C162是一种新型高聚物,研究其对黄土坡面径流过程的影响可为土壤侵蚀的化学调控技术提供新的理论依据。通过室内人工模拟降雨试验,在不同坡度(10°,15°,20°)、降雨强度(1,1.5,2 mm/min)、Jag C162不同撒施剂量(0,1,3,5 g/m2)的组合条件下,研究了Jag C162对坡面径流过程的调控效应。结果表明:(1)撒施中(3 g/m2)、小剂量(1 g/m2)Jag C162的初始产流时间相对裸坡显著滞后(p<0.05),大剂量(5 g/m2)的初始产流时间则显著提前(p<0.05)。(2)不同剂量Jag C162的坡面径流率随径流过程的变化大致趋势为由快速增长逐渐趋于缓慢递增状态。不同剂量Jag C162径流率的大小顺序为:裸土>1 g/m2>5 g/m2>3 g/m2。(3)Jag C162会显著改善>0.25 mm土壤水稳性团聚体含量,显著提高各粒级土壤水稳性团聚体的含量(p<0.05),尤以1～2,2～5,>5 mm粒径的团聚体含量的提高幅度大。因此,Jag C162可显著改善土壤团聚体结构,提高土壤入渗性能,减少地表径流量,从而减弱侵蚀发生的径流动力,达到调控土壤侵蚀的目的。 相似文献
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观察绿脓杆菌的G＋B＋C三个血清型制备的灭活疫苗大规模接种后的速发接种反应及保护性效果观察.用绿脓杆菌G＋B＋C三个血清型制备的疫苗以小鼠和水貂为实验室观察组,同时设定阴性对照,观察疫苗免疫后的速发接种反应;在养殖场,选择常年因绿脓杆菌引起的水貂出血性肺炎的养殖户,采用预防免疫和发病期紧急预防接种两种方式,并回访保护效果.在实验室对水貂和小鼠皮下接种疫苗,接种后7～21 d观察接种部位和解剖小鼠检查病理学变化,没有出现任何异常反应.从2012年和2013年共制备的5个批次14万头份的疫苗,在对临床推广应用的回访中,只有一个养殖户少量水貂出现接种部位化脓,经查是由于注射部位的肌肉吸收性降低而引起,对预防接种的10万头份中,接种后没有发生绿脓杆菌引起的出血性肺炎,在对4万头份的由于绿脓杆菌引起出血性肺炎的紧急接种中,在5～10 d达到控制本病的目的.结论：G＋B＋C三个血清型绿脓杆菌疫苗速发接种反应发生率低,预后良好,无论是预防接种还是发病后紧急接种,均具有较好的保护性. 相似文献