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Phenotypes of inter-alpha-trypsin-inhibitor (ITI) have been determined by isoelectric focusing on polyacrylamide gels followed by immunofixation. The phenotype frequencies of ITI in the Han population in Chengdu, P. R. China have been investigated using this method. In addition, family studies have been conducted in 21 families. The results show that ITI is polymorphic in the Han population in Chengdu, China. The allele frequencies are as follows: ITI*1 = 0.5763. ITI*2 = 0.4107, ITI*3 = 0.0130. ITI is thus a new and promising genetic marker that can be used in the field of forensic haematogenetics. 相似文献
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QUANTITATIVE VARIATION OF ECDYSTEROIDS OF IXODID TICKS 总被引:1,自引:0,他引:1
Abstract In order to explore the role of ecdysteroids in development and reproduction of ixodid ticks, we studied the quantitative variation of ecdysteroids in the hemolymph, synganglion, ovary and whole body of the female ixodid ticks, Dermacentor niveus and Haemaphysalis longicornis , before and after engorgement and oviposition by HPLC and RIA. The ecdysteroid content in eggs of these ticks was determined by HPLC. The results indicated that before engorgement the quantitative variation of ecdysteroids in the whole female body was not significant, but their levels increased rapidly after engorgement. The ecdysteroid titer in hemolymph was peaked on the 5th day after engorgement, which was one day prior to oviposition. It may be regarded as a singnal of oviposition. In the synganglion the peak of ecdysteroid level occurred also on the 5th day after engorgement. This is coincident with the secretory activity of neurosecretory cells of synganglion. From the 3rd day after engorgement until oviposition the ecdysteroid level in the ovary increased rapidly. Ecdysteroids were detected in eggs of H. longicornis too. They stem from ovary and accumulated with the process of embryonic development. 相似文献
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山岳型乡村旅游地“三生”空间演变及优化——德庆金林水乡的案例实证 总被引:1,自引:0,他引:1
以德庆县金林水乡为例,采用参与式观察和空间统计法,选取2000、2008年和2018年3个时段分析旅游发展对山岳型乡村旅游地"三生"空间的影响,并探讨了金林水乡"三生"空间的发展瓶颈及优化路径。研究发现:(1)旅游开发前,金林水乡土地结构与用地功能单一且呈片状分布;村落呈现传统乡村风貌,基础设施不健全;空间形态变化稳定,扩张缓慢。(2)旅游开发后,土地利用类型多样化,出现新型复合用地;土地功能利用复杂化,以服务旅游业为主;村庄景观风貌现代化,生活空间更加宜居。(3)旅游开发前后对比可得,土地平面占地规模化,空间用地以居民点为核心,呈圈层状向外围扩张;生产-生活-生态空间相互转化,乡村聚落重构特征较为显著;村落景观风貌的变化较大,呈现城镇化趋势。(4)金林水乡"三生"空间演化与旅游发展存在的问题表现在生产用地效率不高,生活用地质量较低,生态空间不断萎缩,在旅游产业发展上表现为旅游产品单一且缺乏创新,旅游服务功能不完善等。为此从生活空间的提质、生产空间增效、生态空间保护、旅游产业创新以及土地利用五方面提出优化建议。 相似文献
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Nutrients are assimilated efficiently by Lymantria dispar caterpillars from the mature leaves of trees in the Salicaceae 下载免费PDF全文
Raymond V. Barbehenn Jennifer Knister Frank Marsik Chelsea Jahant‐Miller William Nham 《Physiological Entomology》2015,40(1):72-81
The efficient aquisition of nutrients from leaves by insect herbivores increases their nutrient assimilation rates and overall fitness. Caterpillars of the gypsy moth (Lymantria dispar L.) have high protein assimilation efficiencies (PAE) from the immature leaves of trees such as red oak (Quercus rubra) and sugar maple (Acer saccharum) (71–81%) but significantly lower PAE from their mature leaves (45–52%). By contrast to this pattern, both PAE and carbohydrate assimilation efficiencies (CAE) remain high for L. dispar larvae on the mature leaves of poplar (Populus alba × Populus tremula) grown in greenhouse conditions. The present study tests two alternative hypotheses: (i) outdoor environmental stresses cause decreased nutrient assimilation efficiencies from mature poplar leaves and (ii) nutrients in the mature leaves of trees in the poplar family (Salicaceae) remain readily available for L. dispar larvae. When poplar trees are grown in ambient outdoor conditions, PAE and CAE remain high (approximately 75% and 78%, respectively) in L. dispar larvae, in contrast to the first hypothesis. When larvae feed on the mature leaves of species in the Salicaceae [aspen (Populus tremuloides), cottonwood (Populus deltoides), willow (Salix nigra) and poplar], PAE and CAE also remain high (68–76% and 72–92%, respectively), consistent with the second hypothesis. Larval growth rates are strongly associated with protein assimilation rates, and more strongly associated with protein assimilation rates than with carbohydrate assimilation rates. It is concluded that tree species in the Salicaceae are relatively high‐quality host plants for L. dispar larvae, in part, because nutrients in their mature leaves remain readily available. 相似文献
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Hypertension is an independent risk factor for the progression of chronic renal failure, and oxidative stress plays a critical role in hypertensive renal damage. Forkbox O1(FoxO1) signaling protects cells against oxidative stress and may be a useful target for treating oxidative stress-induced hypertension. Tongxinluo is a traditional Chinese medicine with cardioprotective and renoprotective functions. Therefore, this study aimed to determine the effects of Tongxinluo in hypertensive renal damage in spontaneously hypertensive rats(SHRs)and elucidate the possible involvement of oxidative stress and FoxO1 signaling in its molecular mechanisms. SHRs treated with Tongxinluo for 12 weeks showed a reduction in systolic blood pressure. In addition to increasing creatinine clearance, Tongxinluo decreased urinary albumin excretion, oxidative stress injury markers including malondialdehyde and protein carbonyls, and expression of nicotinamide adenine dinucleotide phosphate oxidase subunits and its activity in SHR kidneys. While decreasing phosphorylation of FoxO1, Tongxinluo also inhibited the phosphorylation of extracellular signal-regulated kinase1/2 and p38 and enhanced manganese superoxide dismutase and catalase activities in SHR kidneys. Furthermore, histology revealed attenuation of glomerulosclerosis and renal podocyte injury, while Tongxinluo decreased the expression of α-smooth muscle actin, extracellular matrixprotein, transforming growth factor β1 and small mothers against decapentaplegic homolog 3,and improved tubulointerstitial fibrosis in SHR kidneys. Finally, Tongxinluo inhibited inflammatory cell infiltration as well as expression of tumor necrosis factor-α and interleukin-6. In conclusion, Tongxinluo protected SHRs against hypertension-induced renal injury by exerting antioxidant, antifibrotic, and anti-inflammatory activities. Moreover, the underlying mechanisms of these effects may involve inhibition of oxidative stress and functional activation of FoxO1 signaling. 相似文献
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An experiment was conducted to investigate the effect of phytase transgenic corn (PTC) on intestinal microflora, and the fate of transgenic DNA and protein in the digesta and tissues of broilers. A total of 160 1-day-old Arbor Acres commercial male broilers were randomly assigned to 20 cages (8 chicks per cage) with 10 cages (replicates) for each treatment. Birds were fed with a diet containing either PTC (54.0% during 1–21 days and 61.0% during 22–42 days) or non-transgenic isogenic control corn (CC) for a duration of 42 days. There were no significant differences (P>0.05) between birds fed with the PTC diets and those fed with the CC diets in the quantities of aerobic bacteria, anaerobic bacteria, colibacillus and lactobacilli, or microbial diversities in the contents of ileum and cecum. Transgenic phyA2 DNA was not detected, but phyA2 protein was detected in the digesta of duodenum and jejunum of broilers fed with the PTC diets. Both transgenic phyA2 DNA and protein fragments were not found in the digesta of the ileum and rectum, heart, liver, kidney, and breast or thigh muscles of broilers fed with the PTC diets. It was concluded that PTC had no adverse effect on the quantity and diversity of gut microorganisms; Transgenic phyA2 DNA or protein was rapidly degraded in the intestinal tract and was not transferred to the tissues of broilers. 相似文献