6 resultados para evidence-in-chief

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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Behavioral stress facilitates long-term depression but impairs long-term potentiation in the hippocampus. Recent evidence in vitro demonstrates that the NIR2B-containing N-methyl-D-aspartate subtype glutamate receptor antagonist Ro25-6981 prevents the beh

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The equatorial Pacific upwelling zone has been suspected of playing an important role in the global atmospheric CO2 changes associated with glacial-interglacial cycles. In order to assess the influencing scope of the surface water deglacial delta(13)C minimum in the tropical low-latitude Pacific, the core DGKS9603, collected from the middle Okinawa Trough, was examined for 4513 C records of planktonic foraminifera N. dutertrei and G. ruber. The planktonic foraminiferal delta(13)C records show a clear decreasing event from 20 to 6 cal. kaBP., which is characterized by long duration of about 14 ka and amplitude shift of 0.4 x 10(-3). Its minimum value occurred at 15.7 cal kaBP. The event shows fairly synchrony with the surface water deglacial delta(13)C minimum identified in the tropical Pacific and its marginal seas. Because there is no evidence in planktonic foraminiferal fauna and 45180 records for upwelling and river runoff enhancement, the broad deglacial delta(13)C minimum event in planktonic foraminiferal records revealed in core DGKS9603 might have been the direct influencing result of the deglacial surface water of the tropical Pacific. The identification for the event in the Okinawa Trough provides new evidence that the water evolution in the tropical low-latitude Pacific plays a key role in large regional, even global carbon cycle.

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Most evidence in terms of endocrine dsiruptors (EDs) mainly originates from studies on reproductive organs. However, in veterbrates, the ability to attain reproductive and development success relays on the intact organization of a complex endocrine system. Disturbances in the regulation of the key hormones and receptors functioning along this system may cause detrimental effects on reproduction and development. Here we reviewed recent studies of EDs on endocrine system. EDs may act on key hormones and receptors along with the hypothalarnic-pituitary-gonald (HPG) axis and lead to reproductive failure. Thyroid disruption may be caused at different levels, for example, the synthesis, transport, binding and cellular uptake along with the hypothalamic-pituitary-thyroid (HPT) axis. Knowledge of model of action EDs is largely via receptors-mediated pathway and alternatively may affect on steroid hormone synthesis. Aquatic hypoxia can influence fish reproduction and thus it is also an endocrine disruptor. Molecular techniques, such as toxicomics, transgenic fish will be employed as powerful tools for environmental EDs risk assessment, as well as in elucidating mechanisms of model action.

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本学位论文共有5章。第一章报道白芍的化学成分及芍药苷的微生物转化研究成果;第二章报道天山雪莲的化学成分研究;第三章报道两面针的化学成分研究;第四章报道通关藤的化学成分研究成果;第五章概述了花椒属植物中最近十年报道的新化合物及药理研究情况。 在第1章的第一部分报道了白芍(Paeonia lactiflora Pall.)的化学成分。我们采用正、反相硅胶柱层析等各种分离方法,从白芍的干燥根中共分离出14个化合物,其中1个为新化合物,其结构通过波谱分析证实为没食子酰白芍苷,另外还有2个为首次从该植物中分离得到。第二部分报道了芍药苷的微生物转化生产芍药苷代谢素-I的研究,从15株厌氧菌中筛选出10株有转化活性的菌株,其中短乳杆菌Lactobacillus brevis AS1.12的转化活性最好,对其转化条件进行了初步的筛选,确定了相对合理的转化工艺。 在第2章报道了天山雪莲(Saussurea involucrate Kar.et Kir.)全草乙醇提取物化学成分的分离纯化和结构鉴定。通过正、反相硅胶柱层析等分离纯化和MS、NMR等波谱解析,共分离鉴定了28个化合物,结构类型分属于黄酮、倍半萜和木脂素等,其中2个新倍半萜化合物的结构分别表征为6α-羟基云木香酸6-β-D-吡喃葡萄糖苷和11βH-11,13-二氢去氢云木香内酯8α-O-(6′-乙酰)-β-D-吡喃葡萄糖苷。 第3章报道了两面针(Zanthoxylum nitidum (Roxb.)DC.)干燥根的乙醇提取物化学成分的分离纯化和结构鉴定。通过正、反相硅胶柱层析等分离纯化和MS、NMR等波谱解析以及X-射线单晶衍射,共分离鉴定了16个生物碱,结构类型分属于苯并啡啶类、喹啉类和阿朴啡类等,其中2个新苯并啡啶类生物碱的结构分别表征为二聚双氢两面针碱和丙酮基双氢崖定椒碱。 第4章报道了通关藤(Marsdenia tenacissima (Roxb.) Wight et Arn.)水提取物化学成分的分离纯化和结构鉴定。通过正、反相硅胶柱层析等分离纯化和MS、NMR等波谱解析以及X-射线单晶衍射,共分离鉴定了14个化合物,结构类型均属于C21多羟基甾醇,其中4个新化合物tenacigenoside A, tenacigenoside B, tenacigenoside C和tenacigenoside D的结构分别表征为3-O-6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→4)-β-D-oleandropyranosyl-17β-tenacigenin B (62), 3-O-2,6- dideoxy-4-O-methyl-D-lyxo-hexopyranosly-11α-O- methylbutyryl-12β-O-acetyl-tenacigenin B (63), 3-O-6-deoxy-3-O-methyl-β-D- allopyranosyl-(1→4)-β-D-oleandropyranosyl-11α-O-tigloyl-tenacigenin C (64)和3-O-6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→4)-β-D-oleandropyranosyl-11α-O-2- methylbutyryl-tenacigenin C (65)。 第5章概述了花椒属植物的化学成分及药理活性研究进展。 This dissertation consists of 5 chapters. The first chapter elaborate the phytochemical investigation of Paeonia lactiflora Pall., and microbial transformation of paeoniforin. The second, third and four chapters elaborate the phytochemical investigation of Saussurea involucrate Kar.et Kir., Zanthoxylum nitidum (Roxb.) DC. and Marsdenia tenacissima (Roxb.) Wight et Arn., respectively. Chapter 5 is a review on chemical constituents and bioactivities of Zanthoxylum species. The part one of chapter 1 focus on the isolation and identification of chemical constituents from P. lactiflora. Fourteen compounds were isolated from the roots of P. lactiflora by repeat column chromatography over normal and reversed phase silica gel. Among them, one is a new compound and the structure was suggested as galloyl-albiflorin by spectral evidence. In addition, two compounds were firstly reported in this plant. The part 2 is about microbial transformation of paeoniforin. Chapters 2, 3 and 4 were isolations and identifications of chemical constituents from S. involucrate, Z. nitidum and M. tenacissima, respectively. From the aerial parts of S. involucrate, 28 compounds including 7 flavonoids and 13 sesquiterpenoids were isolated and identified. Among them, 2 new compounds were characterized as 6α-hydroxycostic acid 6-β-D-glucoside and 11βH-11,13-dihydrodehydro- costuslactone 8α-O-(6'-acetyl)-β-D-glucoside, respectively, by means of spectroscopic analysis. Otherwise, 11 ones were firstly reported from this plant. The third chapter is about the phytochemical investigation of Z. nitidum. Sixteen compounds were isolated and identified. Among them, 2 new benzophenanthridine alkaloids were characterized as 8-acetonyldihydrofagaridine and 1,3-bis(8-dihydronitidinyl)-acetone by spectroscopic analysis. The fourth chapter is about the phytochemical investigation of M. tenacissima. Fourteen compounds were isolated and identified. Among them, 4 new compounds, tenacigenosides A~D, were characterized as 3-O-6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→4)-β-D-oleandropyranosyl-17β- tenacigenin B, 3-O-2,6-dideoxy-4-O-methyl-D-lyxo-hexopyranosly-11α-O-methyl butyryl-12β-O-acetyl-tenacigenin B, 3-O-6-deoxy-3-O-methyl-β-D-allopyranosyl- (1→4)-β-D-oleandropyranosyl-11α-O-tigloyl-tenacigenin C, and 3-O-6-deoxy-3-O- methyl-β-D-allopyranosyl-(1→4)-β-D-oleandropyranosyl-11α-O-2-methylbutyryl- tenacigenin C. Chapter 5 is a review on recent progress in bioactive constituents from plants of Zanthoxylum species.

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genetics, such as: population size, reproduction, mating system, growth, development,genetic structure and systematics status; The main results are presented below: The seasonal variation of the operational sexual ratio of this animal was found in the field and the ration always bias the female in the breeding season. Aiming at this character and considering the distance of time and space of both sexual habitat in breeding season, we census female population first by toe-clipping mark-recapture method, then estimated the population size with the definitive sexual ratio. Up to now, this species was found only at the Beilun district of the Ningbo City. The population size of the Ruiyan Temple Forest Park approximates to 369. The status of this population is extremely endangered, so besides protecting this population at the original locality, we also suggested to breed the salamander in fenced locality and to hatch embryos artificially, and send metamorphosed juveniles back to nature. We can transfer some individuals to other similar habitats or breed them under artificial conditions for saving this species from extinction. The early developmental stage of the Chinhai salamander is the same as its relative species, E. andersoni. Their balanceres are poorly developed and disappear very early. Temperature and moisture significantly influence the embryonic development of the Chinhai salamander. The embryonic stage is approx. 29 days under room temperature. The hatchling grows in a logarithmic curve. The larvae stage in water is approx. 58- 88 days. Many factors influence the nomal development, including two aspects of internal and external. Due to these factors, the effective protected measures were presented in detail. The breeding migration of E. chinhaiensis takes place at late March~late April every year. This salamander's hatching rate is high, but the rate of hatchling migrating into water is low. The average effectiveness of all the nest sites is 36.7%. The maternal self-conservation was contrary to the reproductive success of the egg-laying strategy. In the strategy of egg-laying behavior, the first factor selected by the female was its self-conservation, the second is embryonic survival rate, and the last is rate of hatchling survival rate. The oviposition selection is significant for the survival of the larvae. Based on the analysis of the evolutionary process of reproductive behaviors nad egg-laying site selections of all genera of the family Salamandridae, we deduced that perhaps Echinotriton is a transitional type in the evolutionary process from water to land. Due to its location in the adaptive stage in the terrestrial evolution, Echinotriton chinhaiensis's terrestrial nest may be one of important reason that causes this species to be endangered. The genetic deversity analysis shows that although the population size of the Chinhai salamander is quite small compared to other Chinese salamandrid species, the genetic diversity of this population is not reduce remarkably. We explain this phenomena with the polygamy mating system of this species. The result of 4 families' parenthood determinations shows that the parenhood determination can be taken without any paternal information. The "children" of every female include rich genetic information from at least two "fathers". It implies that female Chinhai salamander mates more than once with different males in a breeding season. The molecular evidence, the behavioral observation evidences and the sperm evidence in the female cloaca proved that this species has a polygamy mating system. The kin recognition in the mating of adult salamander was first discussed. The taxonomic status and phylogenetic relationships of 12 species representing 6 genera in the family Salamandridae were studied using DNA fingerprinting. The results showed that the DNA fingerprinting. The results showed that the DNA fingerprinting patterns demonstrated rich genetic diversity and species diversity, and also revealed the taxonomic status and phylogenetic relationshipes of higher taxa to a certain extent. The results are highly consistent with those obtained from the studies based on the morphology, ecology, cytology and molecular biology. The compreshensive analysis indicate that Tylototrition hainanensis and T. wenxianensis should be valid species; Echinotriton should be a valid genus;Tylotortriton is a natural cluster; Tylotortriton asperrimus should be put in Tylototrition rather than in Echinotriton, Hypselotriton and Allomestriton are synonyms of Cynops and Paramesotriton, respectively. There are three main groups in Chinese salamandride: Cynops, Paramesotriton and Pachytrition from the first group, the species of the Tylototriton from the second, and E. chinhaiensis composes the third.