Inhibitory Action of an Imidazole Compound on Ecdysone Synthesis in Prothoracic Glands of the Silkworm, Bombyx mori

The precocious pupation was induced either by allatectomy at the time of third ecdysis or by topical application of an imidazole compound (KK-42; 1-benzyl-5-[( E )-2, 6-dimethyl-1, 5-heptadienyl] imidazole) to the fourth (penultimate) instar larvae of the silkworm, Bombyx mori. However, the critical period for KK-42 treatment in induction of precocious pupation was longer than that for allatectomy. The effects of KK-42 depended on the doses applied and a half-maximum dose was estimated to be approx. 10 μg/larva. KK-42 suppressed the increase in hemolymph ecdysteroid titres leading to larval ecdysis in controls. Ecdysteroid levels remained at low levels for about 6 days after the treatment, followed by an increase toward precocious pupation. When the prothoracic glands from the mature fifth instar larvac were incubated in vitro in Grace's medium containing various concentrations of KK-42, secretion of ecdysone into the medium was suppressed depending upon the doses of KK-42 added and a half-inhibition concentration was estimated to be approx. 1 nM. Thus, KK-42 was shown to be an inhibitory agent to ecdysteroid secretion in silkworm larvae.     

Reactivation of the Hill reaction of Tris-washed chloroplasts

The Hill reaction of chloroplasts was inhibited by washing themwith 0.8 M Tris buffer. This inhibition was further promotedby adding ferricyanide in the washing medium. When a reducingreagent, such as the 2,6-dichlorophenol indophenol (DCPIP)-ascorbatesystem or the hydroquinone (HQJ-ascorbate system, had been addedto the Tris buffer, Hill reaction activity was unaffected. Hill reaction activity of Tris-washed chloroplasts recoveredup to 70% of the initial level by re-washing the chloroplastswith a preparation medium containing theabove reducing reagents. Photobleaching of carotenoid and chlorophyll is characteristicof Tris-washed chloroplasts. However, reactivated chloroplastsshowed no photobleaching as in the case with intact chloroplasts. (Received April 20, 1970; )     

Non-cyclic photophosphorylation by spinach grana treated with 0.8 M Tris buffer

1. Photophosphorylation was measured with spinach grana sampleswashed by 0.8 M Tris buffer at pH 8.0, which no longer catalyzedthe ferricyanide and NADP HILL reactions with water as the electrondonor. The photophosphorylation with the reaction mixture containing2 10^–4 M 2,6-dichlorophenol indophenol (DCPI) plus above2 10^–3 M ascorbate as the electron donor system insteadof water under anaerobic conditions was, in the most part, dependenton the addition of both PPNR (a nonheme iron protein requisitefor photosynthetic pyridine nucleotide reduction ; spinach ferredoxin)and NADP as the electron acceptor system. However, when ascorbateconcentration only was lowered to 2 10^–4 M, the entirephotophosphorylation proceeded, even in the absence of the electronacceptor system. 2. When the NADP added in the reaction mixture had been reducedby glucose-6-phosphate and glucose-6-phosphate dehydrogenasebefore illumination, the photophosphorylation with 2 10^–4M DCPI plus 6.7 10^–3 M ascorbate decreased to aboutthe same rate as that obtained without NADP. 3. The time course for photophosphorylation in the presenceof NADP was consistent with the time course for the photoreductionof NADP: On the complete reduction of NADP, the photophosphorylationstopped. 4. In the presence of 6.7 10^–3 M dichloropheny 1.1,1-dimethylureaor 3 10^–4 M o-phenanthroline, non-cyclic photophosphorylationwith 2 10^–4 M DCPI plus 6.7 10^–3 M ascorbateas the electron donor system decreased to about half that ofthe control, and the remaining activities were hardly affectedeven at higher concentrations of both inhibitors. The P/2e^–ratios of non-cyclic photophosphorylation in the absence andpresence of ophenanthroline were 0.74 and 0.48, respectively. ¹Present address: Department of Biology, University of California,San Diego, La Jolla, California 92037, U. S. A.     

阿加曲班抗凝对连续血液净化患儿凝血功能及单核细胞TLR2rMnX、TLR4rMnX表达水平的影响

目的:探讨阿加曲班抗凝治疗连续血液净化患儿的疗效及对凝血功能及单核细胞TLR2rMnX、TLR4rMnX表达水平的影响。方法:选取从2017年3月至2018年10月于我院儿童重症医学科接受连续血液净化治疗的患儿86例进行研究,将其按照随机抽签法分成研究组与对照组。对照组予以普通肝素抗凝治疗,研究组予以阿加曲班抗凝治疗。分别比较两组的28 d死亡率、治疗前后凝血功能血小板计数(PLT)、活化部分凝血活酶时间(APTT)、纤维蛋白原(FIB)和单核细胞TLR2rMnX、TLR4rMnX表达水平、治疗过程中滤器与管路凝血程度、使用寿命以及穿刺部位出血情况的差异。结果:研究组28d死亡率(2.33%)比对照组(9.30%)低,但差异无统计学意义(x2=0.849,P=0.357)。治疗后研究组APTT(31.61±1.26)s、FIB水平(6.61±1.80)g/L较对照组的(27.92±1.44)s、(5.58±1.72)g/L明显更高(t=12.646、2.713,P=0.000、0.008)。研究组治疗过程中滤器与管路凝血程度0级人数占比(93.02%)相比对照组(76.74%)较高,而Ⅱ级人数占比(0.00%)相比对照组(9.30%)较低(x2=4.440、4.195,P=0.035,0.041)。研究组穿刺部位出血等级为0级人数占比(93.02%)高于对照组(74.42%),而Ⅱ级人数占比(0.00%)低于对照组(9.30%)(x2=5.460,4.195;P=0.019,0.041)。研究组管路、滤器使用寿命(18.73±7.74)h、(20.84±8.01)h相比对照组的(14.57±6.88)h、(16.20±7.15)h均较长(t=2.634、2.834,P=0.010,0.006)。治疗后研究组单核细胞TLR2rMnX、TLR4rMnX表达水平为(4.72±1.39)、(3.22±0.82),均低于对照组的(8.30±1.44)、(5.11±0.94)(t=11.729、9.936,P=0.000、0.000)。结论:阿加曲班抗凝应用于连续血液净化患儿中的疗效相比普通肝素抗凝更佳,且有利于改善凝血功能和单核细胞TLR2rMnX、TLR4rMnX表达水平,能够降低滤器或管路凝血发生风险,同时有效降低穿刺部位出血风险,增加管路、滤器使用寿命。     

不同时期深施重肥对沙田柚生长结果的影响

比较了夏季深施重肥与冬季深施重肥对沙田柚春梢、根系生长及产量、果实品质、叶片与土壤营养含量的影响。结果表明,夏季深施重肥可在一定程度上提高沙田柚叶片钙、铁、硼、全氮、全磷、全钾、0~40cm土壤速效磷与有机质含量,以及20~40cm土壤的全氮、速效钾和pH值,为根系的生长创造良好的土壤环境条件,进而提高叶片三要素的含量,显著促进新根和春梢的生长;夏季深施重肥的单株产量、单果重量与果实品质与冬季深施重肥间无显著差异。     

Temporal and spatial variation of forest biomass in relation to stand dynamics in a mature,lowland tropical rainforest,Malaysia

To clarify consistency in the size of carbon pool of a lowland tropical rainforest, we calculated changes in above-ground biomass in the Pasoh Forest Reserve, Peninsular Malaysia. We estimated the total above-ground biomass of a mature stand using tree census data obtained in a 6-ha plot every 2years from 1994 to 1998. The total above-ground biomass decreased consistently from 1994 (431Mgha^–1) to 1998 (403Mgha^–1) (1Mg=10³ kg). These are much lower than that in 1973 for a 0.2ha portion of the same area, suggesting that the the total above-ground biomass reduction might have been consistent in recent decades. This trend contrasted with a major trend for neotropical forests. During 1994–1998, the forest gained 23.0 and 0.88Mgha^–1 of the total above-ground biomass by tree growth and recruitment, respectively, and lost 51.9Mgha^–1 by mortality. Overall, the biomass decreased by 28.4Mgha^–1 (i.e. 7.10Mgha^–1·year^–1), which is almost equivalent to losing a 76-cm-diameter living tree per hectare per year. Analysis of positive and negative components of biomass change revealed that deaths of large trees dominated the total above-ground biomass decrease. The forest biomass also varied spatially, with the total above-ground biomass density ranging 212–655Mgha^–1 on a 0.2-ha basis (n= 30 subplots, 1998) and 365–440Mgha^–1 on a 1ha basis. A large decrease of the total above-ground biomass density (>50Mg per ha per 2years) in several 0.2-ha subplots contributed to the overall decrease in the 6-ha total above-ground biomass. In the present study, we discuss the association between forest dynamics and biomass fluctuation, and the implication for carbon cycling in mature forests with emphasis on forest monitoring and assessments of soil and decomposition systems.     

八氢番茄红素合成酶(PSY)的生物信息学分析

目的:通过生物信息学方法对八氢番茄红素合成酶基因(PSY)及氨基酸序列分析,并构建三维结构。方法:运用生物信息学方法对八氢番茄红素合成酶基因及其蛋白质序列的理化性质、亲/疏水性、信号肽、跨膜结构域、糖基化位点,磷酸化位点,二级结构,功能结构域和三级结构进行预测分析。结果:PSY基因含1239bp的开放阅读框,编码氨基酸数为412,为碱性不稳定蛋白;八氢番茄红素合成酶富含Arg、Leu、Ala、Ser、Val等氨基酸,为亲水性蛋白质;PSY为非跨膜蛋白,不含信号肽,具有多个磷酸化位点,α螺旋和无规卷曲是其主要结构元件。结论:用同源建模的方法构建其三维结构,得到合理模型,为采用生物工程提高番茄红素产量提供理论依据。     

大黄鱼对几种饲料蛋白原料消化率的研究

以白鱼粉为主要蛋白源制成参考饲料,以0.1%的Cr2O3为外源性指示剂,按参考饲料和实验原料70%∶30%的比例配制成实验饲料,测定了大黄鱼（Pseudosciaena crocea）对白鱼粉、红鱼粉、肉骨粉、豆粕、花生粕、菜籽粕和棉籽粕的表观消化率。实验大黄鱼（平均初始体重15.0±1.6g）养殖于海水浮式网箱（1.5m×1.5m×2.0m）中,分别以各实验饲料投喂实验鱼5周,然后采用挤压法收集粪便。实验结果表明各原料表观干物质消化率在43.6%至70.0%之间,能量消化率在42.9%到82.6%的范围内。实验原料的蛋白质表观消化率在70.7%到92.4%之间,其中白鱼粉和红鱼粉的蛋白消化率最高（分别为92.4%和89.3%）,而棉籽粕则最低（70.7%）。脂肪的表观消化率在61.3%到90.5%之间,其中棉籽粕最低（61.3%）。磷的表观消化率相对较低,仅白鱼粉和红鱼粉在53.2%以上,其余皆低于37.5%。总之,大黄鱼对这几种原料的表观消化率存在较大差异,但蛋白消化率均较高,因此,可作为大黄鱼的饲料蛋白源在实际饲料配制中使用。