The transdifferentiation of Sca-1+ cells from murine fetal liver

AIM:To explore transdifferentiation potential of Sca-1⁺ cells from murine fetal liver. METHODS:2×10³ of Sca-1⁺ cells from male murine fetal liver were transfused into female mouse irradiated lethally with γ ray from ⁶⁰ Co source (10 Gy) via tail vein. Two months later, FISH and immunohistochemistry were used to detect the situation for transdifferentiating of the donor cells (male cells) in tissues of female recipient mouse. RESULTS:The renal tubular epitheliocyte-like and neurocyte-like cells with Y chromosome were found on the sections of renal and brain tissues from female recipient mice. These cells have phenotype characteristics of RCA⁺/CD₄₅^-F_4/80^- and NueN⁺/CD₄₅^-F_4/80^-, respectively. CONCLUSION:The evidence is provided for Sca-1⁺ cells from murine fetal liver to transdifferentiate into both renal and brain tissue cells.     

山西菜田捕食性食蚜蝇优势种及其对菜蚜的控制效果

对山西菜田捕食性食蚜蝇优势种及对菜蚜的控制效果进行了研究，菜田常见捕食性食蚜蝇有黑带食蚜蝇，大灰食蚜蝇，斜斑鼓额食蚜蝇，野食蚜蝇，四条小食蚜蝇，短翅细腹食蚜蝇6种，以黑带食蚜蝇种群数量最大，平均占全年发生总量的36.3%，通过对食蚜蝇产卵量，卵化率，幼虫期捕食量和羽化率测试，筛选出的黑带食蚜蝇，大灰食蚜蝇，斜斑鼓额食蚜蝇幼虫对菜蚜均有较强的捕食能力，其中黑带食蚜蝇为山西菜田菜蚜捕食性食蚜蝇优势种，用黑带食蚜蝇三龄幼虫对菜蚜进行防治试验，结果以1：180防效最佳，72h后控制效果达93.5%。     

‘新红星’苹果果实蔗糖合酶的活性及亚细胞定位

 在‘新红星’苹果果实发育过程中, 伴随果糖、葡萄糖和蔗糖的积累, 蔗糖合酶的分解活性逐渐下降, 而合成活性逐渐升高。苹果果实的蔗糖合酶由分子量为90 kD 的亚基组成, 其免疫信号强度随发育进程而增加。蔗糖合酶主要定位于果肉细胞的细胞质中, 发育中后期该酶的分布密度有一定增加。综合结果认为, 蔗糖合酶调控发育早期蔗糖的降解和发育后期蔗糖的积累。     

苹果低氧气调新组合贮后效应的利用研究

利用0.12mm聚乙烯薄膜大帐进行低氧气调新组合的较大规模应用试验,对2394kg玫瑰红苹果进行低氧处理,帐内O2浓度可下调至约2%,CO2浓度可自动维持在5%～8%的较理想状态,处理结束后很易转为MA自发气调。低氧处理后再MA贮藏的苹果,虎皮病果率低、症状轻,腐烂果少,果柄和果皮新鲜,叶绿素保持效果好,果肉硬度明显高于小包装气调和冷藏对照。说明利用塑膜大帐进行前期低氧新组合处理与后期自发气调、实现低氧气调新组合贮后效应的利用是可行的。     

Effects of external counterpulsation on renin-angiotensin system and hemodynamics in dogs with myocardial ischemia

AIM:To examine the effect of external counterpulsation(ECP) on renin-angiotensin system(RAS) and hemodynamics in dogs with myocardial ischemia and their relationship. METHODS:Acute myocardial ischemia was induced by occluding the left anterior descending of the dogs. The local renin activity, angiotensin Ⅱ(AngⅡ) level, angiotension-converting enzyme(ACE) activity were tested by biochemical methods and hemodynamics was recorded by a 8-channel physiological recorder.RESULTS:Ischemia could actiivate renin,ACE and AngⅡ in cardiovasculature and ECP reduced them except for renin in ischemic myocardium. Ischemia also could activate RAS in lung and kidney, which play an important role on circulating RAS, and ECP reduced them. Furthermore, ECP could improve hemodynamics and there existed a close relationship between local AngⅡlevel and hemodynamics. CONCLUSION:ECP can reduce local RAS and improve hemodynamics in dogs with myocardial ischemia, which might be one of mechanisms underlying the protective effect of ECP on ischemic myocardium.     

12-(取代苯氧异丁酰氧亚氨基)-1,15-十五内酯的合成及除草活性

通过取代苯氧异丁酸与12-(羟基亚氨基)十五内酯的反应,合成了取代苯氧异丁酰氧亚氨基十五内酯,并测定了其对苋菜的除草活性。所有化合物均经过1H NMR、13C NMR和元素分析确证。初步的生物活性测定结果表明,目标化合物 Ⅲa~Ⅲd 的EC50值分别为34.570、46.492、55.385、50.114 mg/L,其活性比对照药剂2,4-D(117.325 mg/L)高,而比苯磺隆(22.381 mg/L)低。     

黑杨萎蔫枝叶对棉铃虫生殖行为的影响

研究了黑杨(Populus nigra)萎蔫枝叶及其气味对棉铃虫成虫的隐藏部位、产卵部位、交配率及产卵量等的影响，并对黑杨萎蔫枝把在田间诱集到的棉铃虫雌蛾进行了解剖观察。结果表明，在田间，黑杨萎蔫枝把诱集到的棉铃虫93．3％已经交配。在气候箱中，放置黑杨萎蔫枝叶的环境中配对饲养的棉铃虫，经过1个暗期和2个暗期后，其交配率与对照环境中的均无显著差异。在光期开始时，有51．5％的成虫隐藏在饲养笼内所设置的黑杨叶子圆片下，对照纱布圆片下仅有16．7％。叶子圆片所在区域的日平均落卵量显著大于对照区。黑杨萎蔫枝叶及其气味对棉铃虫的产卵前期、产卵持续期、成虫寿命和产下50％的卵所用的时间无显著影响，但饲养笼内有黑杨枝把或黑杨叶片气味存在时，棉铃虫的产卵量比模拟枝把和对照显著提高。     

制约稻粒黑粉病菌冬孢子萌发的关键因素

在相同条件下，从稻田直接收集的病粒中的稻粒黑粉病菌厚垣孢子不能萌发，而取之于仓库中的孢子能萌发。为探明其制约因素，对该病菌进行了光照和浸水时间试验。研究结果表明：稻粒黑粉病菌冬孢子形成后，必须经光照射后，方可进入休眠期；度过5～6个月休眠期的冬孢子，必须浸水48h以上才开始复苏；复苏后的冬孢子必须在光照条件下才能萌发。未完成后熟作用的冬孢子和完成后熟但尚未复苏的冬孢子即使在光照条件下也不能萌发。即稻粒黑粉病菌冬孢子必须经历后熟、休眠、复苏三个阶段后，在适宜的光照与温湿条件下，方可萌发。光照对其冬孢子具有双重作用，促使后熟进入休眠和刺激萌发。     

粉红女士苹果品质特性分析评价

观察测定了粉红女士苹果成熟采收时和常温贮藏后果实的外观、抗性、果实硬度、总酸、可溶性固形物、维生素C、蒸腾失水率、出汁率、果汁密度以及果汁性状;全面分析评价了该品种的外在、内在、贮藏品质和果汁加工特性。结果表明,粉红女士苹果是一个综合性状优良、耐贮藏的鲜食、果汁加工兼用型苹果新品种。     

荔枝环剥时期对新梢生长及碳素储备的影响

 枝梢环剥显著抑制了‘怀枝’荔枝新梢的生长，并导致射线细胞和髓部大量积累淀粉。梢芽萌发或伸长前环剥可完全抑制新梢生长，而新梢快速伸长期环剥对其抑制效应最弱。秋季环剥对新梢的抑制和对淀粉积累的促进效应明显高于春季环剥。环剥口以上的老叶面积和环剥位置并不影响环剥对新梢生长的抑制效应和促进淀粉的积累效应，但环剥口以上单位枝梢长度的叶面积与淀粉含量呈显著正相关。