外源稀土对水稻伤流组分的影响

应用微区试验和伤流测定法研究了外源稀土对水稻根系合成氨基酸和激素的效应,以及对伤流中无机营养离子的影响。结果表明,在本试验条件下,土施低浓度稀土能促进根系合成,显著增加氨基酸总量和激素在伤流中的含量,提高营养离子的吸收;但高浓度稀土却有着明显的抑制效应。应用数学模拟的方法计算出稀土抑制氨基酸合成的半效应值(或50值)约为350～500mg/kg。稀土提高了伤流液中钙的含量,而对磷、钾的含量起抑制效应。     

Mares admitted to a referral hospital for postpartum emergencies: 163 cases (1992–2002)

Objective: To identify and describe the physical, historical, and clinicopathologic characteristics of diseases requiring emergency treatment in postpartum mares, and to evaluate the utility of these characteristics in making an accurate diagnosis in these mares. Design: Retrospective study. Setting: University large animal hospital. Animals: One hundred and sixty‐three mares admitted for emergency treatment within 30 days following parturition between the years 1992 and 2002. Interventions: None. Measurements and main results: Information obtained from the medical records included age, breed, date of admission, sex of the foal from this parturition, time from parturition to admission, duration of clinical signs prior to admission, and any report of dystocia or normal attended delivery, physical examination and clinicopathologic findings and diagnosis. Urogenital hemorrhage and large colon volvulus were the most common diagnoses, comprising 16.6% and 15.9% of total cases, respectively. Older mares were more likely to have a diagnosis of urogenital hemorrhage than younger mares. Mares with urogenital hemorrhage had a median age of 13 years and were admitted to the hospital significantly closer to parturition than mares with other diagnoses. Anemia, hypoproteinemia, and hypofibrinogenemia were significantly associated with a diagnosis of urogenital hemorrhage and occurred in 32%, 36%, and 26% of the mares with urogenital hemorrhage, respectively. Dystocia was more commonly reported (70%) in mares with metritis. Leukopenia was more common (88%) in mares with uterine tears. Conclusions: Careful evaluation of clinicopathologic data can aid the emergency clinician in making a correct diagnosis in postpartum mares with emergent problems.     

毛竹周年采伐的伤流规律研究

毛竹周年采伐是适应竹材加工业发展和市场经济的要求而提出的迫切要求解决的课题。伤流规律的研究是为周年采伐技术提供重要理论依据之一。通过测定分析表明:毛竹在1个生理周期内的伤流量呈两峰两谷分布,一般昼少夜多,降水会增加伤流量。伐桩上的伤流液主要来自鞭系,呈双向运输,以正向运输为主。伤流液营养成分含量因竹龄不同而差异显著,4度竹含量较低。挖笋也会产生伤流,从而引起养分损失。若仅从伤流养分损耗的角度考虑,以正常疏笋为养分损耗参照值,则1个毛竹生理周期中有16个月可以实施采伐。     

鹅枕静脉窦长期大量采血

将１２０只青年鹅分为４组，每组３０只。Ⅰ组为对照组，不进行免疫和采血，Ⅱ、Ⅲ、Ⅳ组进行３个采血期的免疫和鹅枕静脉窦采血，每个采血期采血３次，每２ｄ１次，５０ｍＬ／只。结果表明，在不同饲养条件下，Ⅱ、Ⅲ、Ⅳ组９０只鹅３个采血期的平均采血量在４１０ｍＬ／只以上，且血清抗体效价稳定；在３个采血间期内，Ⅱ、Ⅲ、Ⅳ组鹅的体重恢复率分别为９８．４％、９９．８５％和１００．７５％。由此认为，在同一群鹅内，可进行数个采血期的免疫和枕静脉窦大量采血，且不会影响血清的抗体效价。     

黄牛实验性急性食盐中毒的研究

为查清黄牛急性食盐中毒的中毒剂量及其浓度、临床和血清特征、病理和组织学变化,选健康黄牛6头进行了试验。试验组分A、B两组。给盐量均以2.2克/公斤体重计。A组给6％盐水,B组给10％的盐水,盐后禁饮。结果A组观察38小时未见发病;B组观察14小时、16小时出现典型中毒症状:烦渴频尿、以肌肉痉挛及体位平衡失调为主的神经症状、血清钠剧增;胃溃疡、小肠炎、脑组织出血与水肿。未见嗜酸性白细胞浸润。     

不同杂交水稻品种根系生理特性差异

在田间条件下,对不同杂交水稻品种生育期根系生理特性进行研究。结果表明,各水稻品种生育期内根系生理指标的变化趋势基本一致,但其含量具有明显差异,除根系活力外,其他生理指标的差异在抽穗期达到显著或极显著水平。各品种间,冈优725的根系活力、伤流强度、氨基酸含量及可溶性糖含量在生育期的大部分时间内高于其他水稻品种;Ⅱ优725根系中蛋白质含量和可溶性糖含量在抽穗期较高,而对照品种的各生理指标最低。相关分析表明,所有根系生理指标在大部分生育时期与产量呈正相关,表明通过改良根系生理特性来提高水稻产量是可行的。     

水稻根系活力测定方法及超级稻两优培九生育后期根系活力研究

以孕穗期的两优培九为材料,用伤流法测定根系活力,调查了影响根系伤流收集量的因素。结论如下：在两优培九孕穗期用脱脂棉收集伤流液,以2.0 g的脱脂棉填充量为宜;两优培九主茎和分蘖的伤流量差异显著（P＜0.05）;白天和夜晚的伤流量差异极显著（P＜0.01）;稻桩高低对伤流量影响不显著（P＞0.05）;连续两次测定的差异不显著（P＞0.05）。用上述最佳方法,对两优培九及其对照品种汕优63抽穗后的根系活力（根系伤流强度）进行了调查,结果如下：两优培九抽穗前的根系活力比汕优63相对较高,二者均在抽穗后1周左右出现峰值,随后呈下降趋势,但与汕优63相比,两优培九伤流强度下降幅度相对较大,且一直维持在较低水平。同时,对两个品种抽穗后剑叶叶绿素含量的测定结果表明,两优培九和汕优63的剑叶叶绿素含量抽穗后都迅速下降,但是相对于汕优63,两优培九剑叶叶绿素含量下降速度要慢,能维持相对较高的水平。因此,根系活力的下降可能是两优培九生育后期易早衰的原因。     

Oral Mucosa Bleeding Times of Normal Cats and Cats with Chediak-Higashi Syndrome or Hageman Trait (Factor XII Deficiency)

A commercially available, disposable blade in a spring-loaded cassette was used to measure oral mucosa bleeding times (OMBT) of ketamine/acepromazine-anesthetized cats. The OMBT were determined in cats homozygous for Chediak-Higashi syndrome (CHS, n = 7), cats heterozygous for CHS (n = 6), and cats homozygous for Hageman factor (factor XII) deficiency (n = 5). In addition, OMBT were determined in three groups of normal cats: random-source cats (n = 14), inbred normal relatives of the cats with CHS (n = 7), and inbred normal relatives of Hageman factor deficient cats (n = 9). No significant differences were found in the OMBT of the three groups of normal cats. The mean OMBT for all 30 normal cats was 1.9 minutes +/- 0.5 minutes s.d. Compared to the normal cats, those homozygous for CHS had significantly prolonged OMBT (14.1 +/- 3.3 minutes; p < 0.05). The mean OMBT of cats heterozygous for CHS (2.6 +/- 0.8 minutes) was also significantly longer than the OMBT of the combined normal group. The mean OMBT of the CHS heterozygotes, however, was not significantly longer than that of their normal relatives (OMBT = 1.8 +/- 0.5 minutes), probably because of the low number of cats in this subgroup of normals. As expected, the OMBT of cats homozygous for Hageman factor deficiency (2.3 +/- 0.3 minutes) were not significantly prolonged.