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刺五加化学成分及药理学研究进展 总被引:13,自引:0,他引:13
对国内外刺五加的相关文献资料进行了系统的整理,综述了刺五加的化学成分、药理作用等方面的研究进展,为刺五加进一步的研究和开发提供了较为详尽的资料参考。 相似文献
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土壤生物多样性对植物利用营养物质和水分的影响 总被引:2,自引:0,他引:2
土壤生物多样性影响土壤营养物质和水等自然资源的有效利用是农业生态系统的重要功能.有证据表明土壤微生物多样性可提高土壤营养物质和水的利用率.土壤动物对土壤营养物质和水的有效利用也产生了明显的影响,它主要是通过促进营养物质的转化和改善土壤水渗透率而间接实现的.从已有文献的报道来看,单从某一个方面来研究土壤生物多样性对土壤营养物质和水的有效利用的影响并不能全面地反应它们之间相互作用的规律.因此未来的研究应当把土壤生物多样性、土壤营养物质和水的供给与植物生物多样性、植物营养物质和水的利用率结合起来,这样才有可能从理论上对土壤生物多样性与营养物质和水的利用之间的关系有更加深刻的认识并运用到实践中. 相似文献
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六七月间,从太平洋而来的湿润季风并没有深入到位于银川东部19公里的水洞沟.骄阳烈烈,黄沙阵阵,沟壑纵横,支离破碎是对这片地处半干旱半沙漠地带的旧石器时代遗址并不夸张的写照.
然而,看似贫瘠的地方却往往驻扎最旺盛的生命力.就在那广袤灰黄荒原的一角,手铲簌簌落地的声音已经持续了一个月.那是一支融合着新面孔的考古队伍,怀揣着疑问从千里之外赶来.沙质的黄土随着铲尖的一起一落被层层剥开,沉睡在地层中的史前文明也逐渐显露出来. 相似文献
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生物技术产业是一个高投资、高风险的产业,在各种筹集资金、规避风险的方案中,申请专利成为各国科研工作者和企业家的首选.要成功的获得专利权,首先要了解哪些主题是能够得到专利保护的.各个国家和地区对专利授权的标准不尽相同,通过分析原因和举例说明的方式详细阐述了我国对生物技术领域不予授权的主题.只有不属于这些不可授权主题的发明创造,才有可能成功地获得专利授权. 相似文献
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SCID是一种罕见的先天性免疫缺陷疾病,以严重的T细胞和B细胞功能缺陷为特征.患者自身不具备免疫系统,只能在完全无菌的条件下生存,因此又称.气泡儿童".基因疗法研究的兴起和深入,给SCID的治疗提供了一条新的途径.该文综述了SCID及其基因疗法的研究进展,并对基因疗法的应用前景进行展望. 相似文献
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Survivin的研究现状与RNA干扰在基因治疗中的进展 总被引:1,自引:0,他引:1
Survivin是新近发现的凋亡抑制蛋白,在正常组织中不表达而在恶性肿瘤中高表达,与肿瘤的预后、复发、转移关系密切,具有调控细胞周期,凋亡和增殖的作用;还与对化疗的耐药性和放疗的敏感性有关;此外,与肿瘤新生血管的形成关系也十分密切.针对Survivin这些特性,应用新的基因治疗技术-RNA干扰技术降低Survivin的表达可对肿瘤组织的凋亡和增殖产生影响,由于RNA干扰技术具有的高效性,特异性,长效性,使它成为肿瘤基因治疗的重要方法,应用RNA干扰技术针对Survivin靶位降低Survivin的表达有望成为今后肿瘤基因治疗的方向. 相似文献
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Our aim was to investigate parameters of iron and copper status and oxidative stress and antioxidant function in women with healthy pregnancy, mild and severe preeclampsia with a view to exploring the possible contribution of these parameters to the aetiology. Thirty healthy, 30 mild preeclamptic and 30 severe preeclamptic pregnant women were included. Serum and placental lipid peroxides, and serum vitamin E and total carotene levels were measured by colorimetric assay. Cholesterol, copper, iron, total iron binding capacity (TIBC), ceruloplasmin and transferrin concentrations were measured by commercially available procedures. Data were analysed statistically using one-way analysis of variance and Pearson correlation test. Logistic regression procedures were used to calculate odds ratios. Lipid peroxides in serum and placental tissue, and iron, copper and ceruloplasmin levels in serum were significantly increased, and transferrin, TIBC, vitamin E/total cholesterol and total carotene/total cholesterol ratios in serum were significantly decreased especially in women with severe preeclampsia. Significant correlations were detected between serum iron and lipid peroxides in serum and placental tissue and between serum iron and vitamin E/total cholesterol in severe preeclamptic pregnancy. Furthermore, there were significant correlations between serum malondialdehyde and ceruloplasmin and vitamin E/total cholesterol in women with severe preeclampsia, and changes in serum and placental lipid peroxides and serum iron concentrations were significantly associated with preeclampsia. In conclusion, ischaemic placental tissue may be a primary source of potentially toxic iron in preeclampsia and the released iron species may contribute to the aetiology and would exacerbate lipid peroxidation and endothelial cell injury, which may be abated by antioxidant supplementation. 相似文献
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Phytophagous British insects and mites and their food-plant families: total numbers and polyphagy 总被引:2,自引:0,他引:2
LENA K. WARD DAVID F. SPALDING 《Biological journal of the Linnean Society. Linnean Society of London》1993,49(3):257-276
The Phytophagous Insects Data Base (PIDB) was used to summarize information about 6933 species of British insects/mites and their food-plant families. Total species in 183 insect families on 127 vascular plant families were correlated with numbers of plant species in each family in Britain and Europe, accounting for 41.8% of the variation. Families with trees had more insects, while ferns and aquatic, uncommon and ephemeral plants, particularly orchids, had fewer. Seven individual insect families were analysed separately: Aphididae were more closely correlated with plant species numbers than were the more polyphagous Geometridae. Agromyzidae were uncommon on families with trees. Of insect species 75.8% fed on only one plant family and 10.1% were recorded on two families. Species feeding on three families or more were considered to be polyphagous. In the 30 largest insect families, eight had species feeding on only one plant family, while 12 had more than 20% of their species polyphagous. Proportions of family-restricted insects were high on Pinaceae, Gramineae and Compositae, but low on Corylaceae, Primulaceae and Tiliaceae. More pest species were polyphagous. Polyphagy was related to large larvae, larvae overwintering, wood-feeding, ephemeral food sources, poor dispersal abilities and omnivory. Some polyphagous species might be actively evolving in exploitation of vacant niches, leading to later progressive specialization to food-plants. 相似文献
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Sarah I. Phillips Peter W. Wareing Ambika Dutta Shantanu Panigrahi Victor Medlock 《Mycopathologia》1996,133(1):15-21
The mycoflora of a range of mixed ruminant feed and forage samples collected in Eastern India and Bangladesh were determined. Most fungi isolated from the samples were those associated with low moisture contents. Several potentially mycotoxigenic fungi and thermotolerant species were present particularly in the rice straw. The most frequently isolated fungi were: Aspergillus versicolor (Vuill.) Tiraboschi, Penicillium citrinum Thorn, Eurotium species, Wallemia sebi (Fr.) v. Arx, Aspergillus penicilloides Speg. and yeasts. Fusarium moniliforme Sheldon and Cladosporium species were prevalent in straw but not other feeds. Levels of certain individual fungi, particularly thermotolerant types, were higher in Bangladesh rice straw although overall counts were similar to those of the Indian samples. Mycotoxin analyses for aflatoxins, zearalenone and sterigmatocystin were carried out. Aflatoxins were detected in significant amounts in some feed samples from Eastern India but not in rice straw from India and Bangladesh. Zearalenone occurred in a Paspalum straw sample and three other feed samples from India and sterigmatocystin was detected in three rice straw samples from Bangladesh. 相似文献
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Occurrence and levels of indicators and selected pathogens in different sludges and biosolids 总被引:2,自引:0,他引:2
AIMS: Determine the occurrence and levels of pathogens and indicators in raw and treated sludges and compare their persistence after two different treatments. METHODS AND RESULTS: Helminth ova, Cryptosporidium spp., Salmonella spp., enteroviruses, and bacterial and viral indicators were determined in raw sludges and biosolids produced after mesophilic and thermophilic treatments. Except Salmonella, all of the parameters were quantified. Helminth ova were found at very low concentrations even in raw sludges. Viable Cryptosporidium oocysts were still present in most samples of treated sludges. Faecal coliforms, spores of sulphite-reducing clostridia (SSRC), and somatic coliphages were the only indicators with values above their detection limits in most of the samples. CONCLUSIONS: Pathogens were still detected in some treated sludge samples. SSRC were the most resistant micro-organisms to treatments and hence may be an indicator for the reduction of protozoan oocysts. Somatic coliphages constitute an alternative as viral indicators due to their detection in sludges before and after treatment. SIGNIFICANCE AND IMPACT OF THE STUDY: Because of the persistence of some pathogens after sludge treatments, additional indicators are needed. SSRC and somatic coliphages are good candidates. Easy and inexpensive methods for the determination of these indicators are feasible both in industrialized and developing countries. 相似文献
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Postpartum lactating cows (N=118) and virgin heifers (N=60) were treated with subcutaneous Norgestomet implants for nine days and received either an intramuscular injection (im) of 5 mg estradiol valerate and 3 mg Norgestomet at the time of implant insertion or an im injection of 5 mg Alfaprostol 24 hr before implant removal. Animals were artificially inseminated 12 hr after detection of estrus. Of the cows and heifers, 78% and 88%, respectively, were in estrus within five days after implant removal (P<0.09). There was no difference between treatments in the proportion of animals in estrus or in the timing of estrus (P<0.85). Estrus was detected in a greater (P<0.05) proportion of animals that were cyclic prior to treatment (88%) than among those that were anestrous prior to treatment (77%). Pregnancy rates after five days were similar between heifers that were cyclic (42%) or anestrous (47%) prior to treatment; however, the five-day pregnancy rate in cows that were anestrous prior to treatment was 38% lower than that in cows that were cyclic prior to treatment (17 vs 55%, P<0.01). Although the treatments synchronized or induced estrus in both cyclic and anestrous animals, marked variability in estrous response and fertility among previously cyclic or anestrous postpartum cows limited the effectiveness of the treatments. 相似文献
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激动素、脱落酸和丙二醛对SOD活性影响及其与SOD构象和疏水性变化间的关系研究 总被引:1,自引:0,他引:1
激动素、脱落酸和丙二醛对SOD活性影响及其与SOD构象和疏水性变化间的关系研究伍泽堂候万儒(四川师范学院生物系,南充637000)我们在实验中曾发现激动素(KT)激活小麦SOD活性,脱落酸(ABA)、丙二醛(MDA)抑制小麦超氧化物歧化酶(SOD)活... 相似文献
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《Bioorganic & medicinal chemistry》2014,22(9):2655-2661
Coumarins are extensively studied anticoagulants that exert additional effects such as anticancerogenic and even anti-inflammatory. In order to find new drugs with anticancer activities, we report here the synthesis and the structural analysis of new coumarin derivatives which combine the coumarin core and five member heterocycles in hydrazinylidene-chroman-2,4-diones. The derivatives were prepared by derivatization of the appropriate heterocyclic amines which were used as electrophiles to attack the coumarin ring. The structures were characterized by spectroscopic techniques including IR, NMR, 2D-NMR and MS. These derivatives were further characterized especially in terms of a potential cytotoxic and apoptogenic effect in several cancer cell lines including the breast and prostate cancer cell lines MCF-7, MDA-MB-231, PC-3, LNCaP, and the monocytic leukemia cell line U937. Cell viability was determined after 48 h and 72 h of treatment with the novel compounds by MTT assay and the 50% inhibitory concentrations (EC50 values) were determined. Out of the 8 novel compounds screened for reduced cell viability, 4c, 4d and 4e were found to be the most promising and effective ones having EC50 values that were several fold reduced when compared to the reference substance 4-hydroxycoumarin. However, the effects were cancer cell line dependent. The breast cancer MDA-MB-231 cells, the prostate cancer LNCaP cells, and U937 cells were most sensitive, MCF-7 cells were less sensitive, and PC-3 cells were more resistant. Reduced cell viability was accompanied by increased apoptosis as shown by PARP-1 cleavage and reduced activity of the survival protein kinase Akt.In summary, this study has identified three novel coumarin derivatives that in comparison to 4-hydroxycoumarin have a higher efficiency to reduce cancer cell viability and trigger apoptosis and therefore may represent interesting novel drug candidates. 相似文献
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Maternal and fetal cadmium and selenium status in normotensive and hypertensive pregnancy 总被引:3,自引:0,他引:3
Kosanovic M Jokanovic M Jevremovic M Dobric S Bokonjic D 《Biological trace element research》2002,89(2):97-103
Cadmium and selenium concentrations in maternal and umbilical cord blood and amniotic fluid were determined in 37 normotensive
and 23 hypertensive women during the last trimester of pregnancy in relation to their smoking status. Thiocyanate concentration
in plasma was used as the index of smoking status. Cadmium and selenium were determined with atomic absorption spectrometry
(graphite furnace and mercury hydride system). In the group of normotensive and hypertensive women, significantly higher cadmium
and lower selenium concentrations in blood in smokers were observed than in nonsmokers. Umbilical cord blood selenium concentrations
in both normotensive and hypertensive smokers were significantly lower than in nonsmokers as well. In the group of normotensive
women, significant differences in selenium concentrations in amniotic fluid were observed between smokers and nonsmokers.
In conclusion, the results of this study show that hypertension in pregnant women smokers is related to significantly higher
blood cadmium concentrations, which indicates that cadmium may be considered as an independent factor involved in hypertension. 相似文献
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Objective To amplify the cDNA genes of GPIIb, GPIIIa, then construct the eukaryotic expression carriers of GPIIb and GPIIIa respectively, finally establish CHO cell lines stably expressing GPIIb and GPIIIa.
Methods Human erythroleukemia (HEL) cells were cultured for total RNA extraction. RT-PCR was accomplished using the specific GPIIb,
GPIIIa primers designed according to Genbank by Primer 5, then each of cDNAs were obtained. The expressive vector pcDNA3.1(+)
and PCR products were cut by NheI and HindIII, and then the fragements were directly cloned to pcDNA3.1(+) because of having the same adhesive ends. Then pcDNA3.1(+)IIb
and pcDNA3.1(+)IIIa were transfected into CHO cells respectively by Lipofectamine 2000. The cell lines expressing GPIIb, GPIIIa
were screened by G418. Then the Chinese hamster ovary (CHO) cell lines were examed through flow cytometry (FCM) and RT-PCR
to detect the expression of GPIIb, GPIIIa in CHO cells.
Results The cDNAs of GPIIb and GPIIIa were amplidied by RT-PCR, and the pcDNA3.1(+)IIb and pcDNA3.1(+)IIIa were constructed respectively. By sequencing and double digestion, pcDNA3.1(+)IIb and pcDNA3.1(+)IIIa were all correct. Expression of GPIIb and GPIIIa were detected on transfected CHO cells
by FCM and RT-PCR.
Conclusions (1) Succeeded in constructing pcDNA3.1(+)IIb, pcDNA3.1(+)IIIa. (2) Succeeded in getting the cell lines expressing GPIIb, GPIIIa. 相似文献
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神农架大九湖湿地公园独具特色的高山湿地生态系统孕育了独具特色的动植物资源,但其两栖动物和爬行动物物种多样性尚未报道。为此,2016至2018年对该区域的两栖动物和爬行动物进行了调查。共记录两栖动物21种,隶属于2目8科。其中,东洋种17种,古北种1种,广布种3种;湖北省级保护动物12种;IUCN收录21种,其中棘腹蛙(Quasipaa boulengeri)为濒危级(EN),秦巴巴鲵(Liua tsinpaensis)、棘胸蛙(Q.spinosa)为易危级(VU);《中国脊椎动物红色名录》收录21种;中国特有种10种,主要分布于中国的有5种。共记录爬行动物31种,隶属于2目13科。其中,东洋种23种,古北种1种,广布种7种;湖北省级保护动物8种;IUCN收录24种,其中,乌龟(Mauremys reevesii)为濒危级(EN),舟山眼镜蛇(Naja atra)为易危级(VU);CITES附录Ⅱ收录舟山眼镜蛇、附录Ⅲ收录乌龟;《中国脊椎动物红色名录》收录11种;中国特有种12种,主要分布于中国的有13种。结果表明,该区域的两栖动物和爬行动物具有种类较多、东洋界物种占优势、中国特有种及受保护物种较多的特点。调查结果有助于全面了解神农架大九湖湿地公园生物资源概况,为科学保护和管理提供基础资料。 相似文献