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991.
秋茄红树植物落叶分解的碎屑能量研究   总被引:6,自引:0,他引:6  
测定了红树植物秋茄(Kandelia candel (L.) Druce)落叶在不同季节分解过程中碎屑的热值和富能有机化合物的变化。结果表明,季节间落叶的热值差别不大,平均为19.63 kJ/g干重或21.55 kJ/g 去灰分干重。各季节的落叶在其分解后的碎屑的热值均明显提高,且夏秋季快于冬春季,但它们与分解程度有相应的相关关系:分解初期上升,后期稍降,最大值出现在半分解期(失重50% )附近。碎屑的最大热值平均比落叶的热值提高17.67% (干重热值)或14.35% (失灰分干重热值)。分解中总能量的耗散稍慢于干物质的损失。随分解的进行,碎屑中粗蛋白、粗脂肪、粗纤维的能量增大,而无氮浸出物的能量减少。  相似文献   
992.
根据现有的光合作用和蒸腾作用的模型,利用Ball-Berry 的气孔导度模型,将叶片的光合作用模型和蒸腾作用模型结合起来,建立了光强(I)、叶片-大气水汽饱和差(VPD)和大气CO2 浓度(Ca)等环境因子对小麦叶片水分利用效率(WUE)影响的模型。由于这3 种环境因子对光合、蒸腾的影响方式上的差异,作为两者之比的叶片WUE随各环境因子的变化出现复杂的图景,同时,在人工气候箱内分别于这3 个因子变化时对光合、蒸腾的变化作了测定,计算了叶片的W UE。测定结果与模拟结果的对比表明,在多数情况下两者符合程度良好,但在高Ca下有较大的偏离  相似文献   
993.
We used quantitative histochemistry to investigate the tissue-specific compartmentation of potassium in the laminar pulvinus of Phaseolus coccineus L. at day and night positions of diurnal leaf movement. The assay was based on the potassium-dependent activation of pyruvate kinase. Total potassium levels of pulvini were higher in the light than in the dark [0.88 and 0.57mol (kg dry weight)?1, respectively]. Transverse compartmentation of potassium was studied on three tissue slices, representing the middle part, petiolar and laminar sides of individual pulvini. These were dissected further into 10 distinct subsamples (bundle; motor tissues: extensor, flexor; flanks). In the day position the amount of potassium in the extensor was higher than in the night position [1.92 and 1.50 mol (kg dry weight)?1, respectively]. Flexor changes were opposite [1.13 and 1.65 mol (kg dry weight)?1, respectively]. In the day position there was a steep and consistent increase in potassium content from the innermost to the outermost zones of the extensor. In the night position this was much more variable. Comparable gradients were not detected in flexor samples. Here highest amounts of potassium were recovered from the middle of the motor tissue. The data specify distinct tissue regions involved in osmotic adjustment during leaf movement in Phaseolus coccineus.  相似文献   
994.
摘要 目的:观察右美托咪定对腰麻下老年髋关节置换术(THA)患者应激反应、肾脏功能及睡眠质量的影响。方法:选择2019年10月到2022年10月期间徐州医科大学附属连云港医院收治的84例拟择期在腰麻下行THA的老年患者,按照随机数字表法将其分为对照组(常规腰麻,n=42)和观察组(常规腰麻联合右美托咪定,n=42)。观察两组镇静、镇痛评分、应激反应、肾脏功能、睡眠质量、谵妄发生率和不良反应发生率。结果:观察组术后12 h、术后1 d Ramsay镇静评分高于对照组,视觉模拟疼痛量表(VAS)评分低于对照组(P<0.05)。观察组术后1 d、术后7 d匹兹堡睡眠质量指数(PSQI)评分低于对照组(P<0.05)。观察组术后1 d皮质醇(Cor)、肾上腺素(E)、去甲肾上腺素(NE)低于对照组(P<0.05)。观察组术后1 d肌酐(Cr)、血尿素氮(BUN)、中性粒细胞明胶酶相关脂质运载蛋白(NGAL)低于对照组(P<0.05)。两组的围术期不良反应发生率对比无差异(P>0.05)。观察组的术后谵妄发生率低于对照组(P<0.05)。结论:右美托咪定用于腰麻下老年THA患者,可减轻应激反应,减轻肾脏功能损伤,降低对人体睡眠质量的影响,减少谵妄的发生率,有较好的麻醉效果。  相似文献   
995.
摘要 目的:对比内侧开放楔形胫骨高位截骨术(OWHTO)、人工全膝关节置换术(TKA)治疗膝关节内翻畸形的疗效及对术后下肢力线和创伤应激的影响。方法:回顾性分析贵州医科大学附属医院2020年3月~2022年1月期间接收的膝关节内翻畸形患者临床资料,共计75例。根据手术方案的不同分为OWHTO组(n=40)和TKA组(n=35)。对比两组围术期指标、视觉疼痛模拟评分(VAS)评分、美国特种外科医院(HSS)膝关节评分、膝关节活动度(ROM)、应激指标和术后下肢力线改变情况。结果:OWHTO组手术时间、切口长度短于TKA组,术中出血量、住院费用少于TKA组(P<0.05)。OWHTO组术后1个月VAS评分低于TKA组,ROM、HSS膝关节评分高于对照组(P<0.05)。OWHTO组术后3 d、术后7 d血清皮质醇(COR)、促肾上腺皮质激素(ACTH)水平低于TKA组(P<0.05)。两组术后6个月股胫角(FTA)下降,髋-膝-踝角(HKA)升高(P<0.05)。两组术后6个月FTA、HKA组间对比差异不显著(P>0.05)。两组并发症发生率组间对比未见差异(P>0.05)。结论:OWHTO、TKA这两种治疗方案治疗膝关节内翻畸形,具有相当的疗效,均可有效改善下肢力线,但OWHTO的创伤小、应激程度轻。  相似文献   
996.
Summary Peanut (Arachis hypogaea L., Var. TMV-2) plants were raised in sand cultures under natural photoperiod. Salt treatment (0.4% NaCl on dry weight basis) was given 10 days after sowing. Nutrient solution was supplied 15 days after sowing to control and salinized plants. Phosphate (0.1% NaH2PO4 with 0.01% Tween-80) was sprayed to the plants to the drip point once daily from 20th to 25th day and from 30th to 35th day. The plants were harvested at 30th and 40th day for analysis. The plants grown under saline conditions showed a market reduction in growth. When phosphorus was supplied to saline plants by foliar application, there was an increase in dry weight, leaf area, stomatal frequency, and yield and the increase was more marked when the plants received phosphate for two periods. Phosphorus content decreased due to salinity which was restored by foliar spray of phosphate. With salinity, sodium accumulated while potassium and calcium were lowered. Phosphate spray decreased sodium and increased potassium and calcium in general.  相似文献   
997.
The activities of several enzymes, including ribulose-1,5-diphosphate (RuDP) carboxylase (EC 4.1.1.39) and phosphoenolpyruvate (PEP) carboxylase (EC 4.1.1.31) were measured as a function of leaf age in Z. mays. Mature leaf tissue had a RuDP-carboxylase activity of 296.7 mol CO2 g-1 fresh weight h-1 and a PEP-carboxylase activity of 660.6 mol CO2 g-1 fresh weight h-1. In young corn leaves the activity of the two enzymes was 11 and 29%, respectively, of the mature leaves. In senescent leaf tissue, RuDP carboxylase activity declined more rapidly than that of any of the other enzymes assayed. On a relative basis the activities of NADP malic enzyme (EC 1.1.1.40), aspartate (EC 2.6.1.1) and alanine aminotransferase (EC 2.6.1.2), and NAD malate dehydrogenase (EC 1.1.1.37) exceeded those of both PEP and RuDP carboxylase in young and senescent leaf tissue. Pulse-chase labeling experiments with mature and senescent leaf tissue show that the predominant C4 acid differs between the two leaf ages. Labeling of alanine in senescent tissue never exceeded 4% of the total 14C remaining during the chase period, while in mature leaf tissue alanine accounted for 20% of the total after 60 s in 12CO2. The activity of RuDP carboxylase during leaf ontogeny in Z. mays parallels the development of the activity of this enzyme in C3 plants.Abbreviations RuDP ribulose-1,5-diphosphate - PEP phosphoenol pyruvate - PGA 3-phosphoglycerate  相似文献   
998.
M. Bodson 《Planta》1977,135(1):19-23
Vegetative plants of Sinapis alba L. were induced to flower by a single long day of 20 h or by a single short day of 8 h starting at an unusual time of the 24-h cycle (displaced short day). The soluble sugar and starch contents of the just-expanded leaf and the apical bud were measured at various times after the start of each of these two photoinductive treatments. Associated with the induction of flowering there were temporary increases in the soluble sugar and starch contents of the leaf and of the bud. These increases were apparent 14 h after the start of the long day and 12 h after the start of the displaced short day. The starch content of the bud increased later. These results indicate that an increase of the soluble sugar content of the bud is required for its transition from the vegetative to the reproductive condition.  相似文献   
999.
D. Gradmann  W.-E. Mayer 《Planta》1977,137(1):19-24
The internal potential of flexor cells in slices of the laminar pulvini of Phaseolus coccineus has been recorded by standard microelectrode techniques in 100 eq m-3 external salt solutions of various ionic compositions. The measured values are between-15 and-60 mV depending on the external medium. Treating the results with the Goldman equation yields the following relative permeabilities: K+, 1.00; Na+, 0.24; Cl-, 0.19; NO 3 - , 1.6. The membrane potential was only slightly sensitive to external pH and Ca2+. Metabolic inhibitors (azide, cyanide and salicylhydroxamic acid, carbonyl cyanid m-chlorphenyl hydrazone) caused only slight depolarizations (ca. 4 mV), which differed from the ion-induced changes by their slow time courses. The results are consistent with the hypothesis that the relatively impermeable Cl- is actively transported and osmotically efficient, whereas the well-permeable K+ passively follows Cl- to maintain electroneutrality and is osmotically of only minor significance.Abbreviations SHAM salicylhydroxamic acid - CCCP carbonyl cyanid m-chlorphenyl hydrazone  相似文献   
1000.
Leaf water potentials of Phaseolus vulgaris L. plants exposed to a -3.0 bar root medium were reduced to between -7 and -9 bars within 25 min and remained constant for the next several hours. This treatment led to considerable variation between leaves in both abscisic-acid (ABA) content and Rs, although the two were well correlated after a 5-h treatment. There was an apparent 7-fold increase in leaf ABA levels necessary to initiate stomatal closure when plants were exposed to a -3.0 bar treatment, but when plants were exposed to a -5.0 bar stress Rs values increased prior to any detectable rise in ABA levels. To explain these seemingly contradictory results, we suggest that the rate of ABA synthesis in the leaf, rather than the total ABA content, determines the status of the stomatal aperture.Abbreviations ABA abscisic acid - PEG polyethylene glycol - Rs stomatal diffusion resistance of lower leaf surface - leaf water potential  相似文献   
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