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【目的】淀粉降解与水稻浆片膨大和颖花开放过程密切相关,探究α-淀粉酶基因在颖花开放过程中的作用,为杂交水稻制种效率及产量的提高提供理论依据。【方法】在水稻扬花时,利用稀释碱性品红溶液进行离体穗子吸水试验,观察碱性品红在颖花中残留的组织,通过碘-碘化钾染色法确定11—14期(依据雄蕊发育分期)淀粉粒的分布变化,并通过RT-PCR、RT-qPCR和GUS报告基因检测多个α-淀粉酶基因在此期间的时空表达模式。【结果】水稻颖花开放前,内外稃片通过相互嵌合的钩合槽(marginal tissues of palea,mtp)将浆片和雌雄蕊封闭在内。当颖花开放时,浆片快速膨大,使得内外稃片的钩合点松开。扬花期间,离体穗子在稀释碱性品红溶液中吸水后,碱性品红染料主要残留在内外稃片钩合槽和浆片相连处组织以及花丝中。碘染试验显示,在12期(颖花开放前),淀粉粒主要分布在雄蕊和内外稃片钩合槽,浆片中也有少量淀粉粒,在13—14期(颖花开放中),内外稃片钩合槽和浆片中的淀粉粒均降解。RT-PCR分析发现OsRAmy2A和OsRAmy3D的表达量从12期开始上升,至13—14期表达量显著增强,到受精后1 d(... 相似文献
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Oil palm trunk is an excellent raw material for thermally compressed wood board.However,improvements to dimensional stability during water absorption and reduced thickness swelling has been tied to losses in other mechanical properties,especially as the compression temperature is increased.Toward solving this trade-off,we analyzed the effects of a 48 h pre-soak in citric acid solutions(0,5,15,25,or 35%w/v in distilled water)on the physical and mechanical properties of oil palm board compressed at 140℃.The reference benchmark case was compressed at 200℃without pretreatment.The oil palm board raw materials were obtained from outer,middle and inner parts of trunk.The results showed that the oven-dry density of compressed oil palm board made from different parts of trunk increased with thermal compression(maximum pressure 12.26 MPa for 8 min).The citric acid pretreatment improved water absorption and thickness swelling properties of oil palm board thermally compressed at 140℃,consistent with the citric acid concentration.The carboxyl groups in citric acid cross-link with the hydroxyl groups in the wood.However,no significant difference was found between the benchmark(200℃)and pretreatments with 5 or 15%citric acid.The citric acid altered the wood chemistry during hot compressing at 140℃.Static bending strength,modulus of rupture(MOR),and modulus of elasticity(MOE)slightly decreased with the citric acid pretreatment,matching the effects of high temperature compression at 200℃. 相似文献
24.
Hideaki Korai Kimihiro Uemura Takuji Esashi Masaharu Suzuki 《Journal of Wood Science》1999,45(5):402-410
The purpose of this study was to reveal the effects of various levels of mat-moisture content (m.m.c.) and the closed-press system for making single- or three-layer particleboard on the density profile, thickness swelling, specific moduli of elasticity (MOE) and rupture (MOR) and internal bond strength. Internal gas pressure was measured in an enclosed frame; and the larger the m.m.c., the higher the internal gas pressure became. When rising water vapor (steam) struck particles, it plasticized them and cured the adhesive, resulting in improved interparticle contact. The vertical density gradient in the three-layer board was larger than that in the single-layer board. As for thickness swelling by cold-water soaking, the single-layer boards were less affected than the three-layer boards and showed good dimensional stability with increased m.m.c. The open-system boards swelled more than the closed-system boards. The closed-system single-layer board made at high m.m.c. returned nearly to the prime thickness by air-drying after cold-water soaking. Specific MOE and MOR were larger at 15% or 10% m.m.c. than those at other m.m.c. Considerable reductions of specific MOR and MOE of the closed-system three-layer board were observed at 20% or 25% m.m.c.Part of this report was presented at the 45th annual meeting of the Japan Wood Research Society, Tokyo, April 1995 and at the 48th annual meeting of the Japan Wood Research Society, Shizuoka, April 1998 相似文献
25.
用剪刀剪、锉子锉、与瓜子石混搓等机械处理法以及用5%氢氧化钾、98%浓硫酸等化学处理法对神黄豆种子进行预处理,3倍种子体积沸水浸泡并自然冷却浸种48 h,观察并统计种子吸胀粒数、种皮破裂数后置床进行发芽测定。结果表明,除与瓜子石混搓处理外,其余处理均能促进种子吸水膨胀,显著提高神黄豆种子发芽率。其中以98%浓硫酸浸泡2 h处理效果最好,其吸胀率达98.0%、发芽率最高,达88.3%,吸胀破皮率、不正常发芽率均为0%;其次是锉子锉处理效果好,其吸胀率达99.0%,发芽率可达84.7%,吸胀破皮率、不正常发芽率均为0%;用5%氢氧化钾进行浸泡处理,对种子发芽有一定的促进作用,但发芽不整齐,发芽速度慢,处理14 d吸胀率为59.7%、发芽率最高为48.0%;与瓜子石混搓处理效果相对较差,对神黄豆种子发芽的促进作用不明显,吸胀率为5.0%、发芽率为5.0%。 相似文献
26.
The mobility of chlorfenvinphos in isolated pear (Pyrus communis cv. Bartlett) leaf cuticular membranes (CM) was studied as a function of concentration of chlorfenvinphos sorbed in the cuticle. Mobilities of chlorfenvinphos increased approximately 9-fold when the amount sorbed increased from 1 to 100 μg cm−2 pear leaf cuticle. From the amounts per area, average volume fractions of chlorfenvinphos in the cuticle were calculated ranging from 2×10−3 to 5·1×10−2. The increase in mobilities was steepest at the lower and levelled off at higher volume fractions. This correlation could be described for the whole range of volume fractions investigated by an equation which assumes homogeneously dispersed chlorfenvinphos. Temperature dependence of mobilities was studied at 17, 25 and 35°C and chlorfenvinphos volume fractions of 5·5×10−3 and 0·12, respectively. Arrhenius graphs were linear for both volume fractions, showing that cuticles did not undergo a phase transition due to the high amount of sorbed chlorfenvinphos. However, at a volume fraction of 0·12, the activation energy of diffusion, ED, was significantly lower (83·6 kJ mol−1) than at 5·5×10−3 (135 kJ mol−1). We interpret these findings as evidence for a plasticising effect on cuticular waxes by chlorfenvinphos. So far, such an effect had been demonstrated only for certain adjuvants (ethoxylated alcohols) but not for active ingredients. Chlorfenvinphos not only increased its own mobility in pear leaf cuticles, but also that of 2,4-D in Citrus leaf cuticles. This would be expected if plasticising of waxes was the sole mechanism responsible for increased mobilities. From these data we predict that permeabilities of cuticles to chlorfenvinphos are not constant. Depending on temperature as well as types and amounts of adjuvants, rates of foliar penetration of chlorfenvinphos can be higher if its concentration in the spray liquid is increased. 相似文献
27.
目的 观察消肿方结合四子散外敷治疗甲状腺术后肿胀的疗效。方法 将甲状腺术后一周肿胀患者随机分成两组。治疗组(52例)给予内服消肿方,同时使用四子散外敷颈部;对照组(48例)常规使用TDP治疗仪理疗,一个疗程后比较两组肿胀消退情况、颈部不适感发生率、炎症指标等。结果 治疗组经治疗后肿胀消退有效率(96.15%)高于对照组(81.25%),两组差异有统计学意义(P<0.05);治疗组经治疗后颈部不适感发生率低于对照组,差异有统计学意义(P<0.05);治疗组经治疗后肿瘤坏死因子(TNF-α)和白介素-6(IL-6)水平低于对照组,差异有统计学意义(P<0.05)。两组治疗后均无不良反应发生。结论 消肿方结合四子散外敷是治疗甲状腺术后肿胀的有效方法,效果显著,用药安全,值得推广。 相似文献
28.
葵花子皮中水溶性膳食纤维初步研究 总被引:2,自引:1,他引:1
为了提高葵花子皮中水溶性膳食纤维得率,在单因素实验基础上,通过响应面法对水溶性膳食纤维提取工艺进行优化研究。结果表明:提取瓜子皮中水溶性膳食纤维的最佳工艺参数为NaOH的质量分数为7.83%、提取时间为69.46 min、提取温度为42.10℃、液料比为40 mL/g;在最优工艺条件下水溶性膳食纤维的得率可达31.1112%,同时经测定得知葵花子皮膳食纤维具有良好的持水性和溶胀性:持水性为7.293 g/g,溶胀性为3.997 mL/g。因此瓜子皮可以作为提取水溶性膳食纤维的良好来源。 相似文献
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为了解促炎、抗炎细胞因子在小鼠LPS致炎模型中的动态变化,探讨中药方剂清温消热饮的抗炎治疗作用,采用酶联免疫法测定112例用LPS致小鼠急性炎症模型治疗过程中血清中促炎因子(TNF-α、IL-1β、PGE2)、抗炎因子(IL-10)含量。与LPS致小鼠急性炎症模型组比较:清温消热饮组在18、24 h血清中IL-1β含量明显降低,差异显著(P0.05);清温消热饮组在6、12、18 h血清中TNF-α含量明显降低,6、18 h差异显著(P0.05),12 h差异极显著(P0.01);清温消热饮组血清中的PGE2含量均低于模型组,在6、18、24、36 h时血清中的PGE2含量明显降低,差异极显著(P0.01);清温消热饮组在18、48 h血清中IL-10含量明显升高,差异极显著(P0.01)。同时,清温消热饮组与地塞米松组在各时间段血清中TNF-α、IL-1β、IL-10、PGE2含量无显著差异(P0.05)。结果表明,清温消热饮在急性炎症模型中能有效降低血清促炎因子TNF-α、IL-1β、PGE2含量水平,提升抗炎因子(IL-10)含量水平以表现出明显的抗炎作用。 相似文献