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21.
《Biotechnic & histochemistry》2013,88(2):53-56
Anthers are collected and placed in a solution of 1 part acetic acid to 3 parts of absolute alcohol. The contents of the anther are squeezed out on a slide in a drop of Belling's iron-aceto-carmin solution and a cover glass placed over the drop. Care should be taken to remove all anther walls and flower parts. Heat the slide over an alcohol flame for a second, repeating 4 or 5 times. Place the slide in a petri dish filled with a 10% solution of acetic acid. When the cover glass has risen away from the slide gently remove the cover glass and place in a Coplin jar containing equal parts of alcohol and acetic acid. Likewise, place the slide in this solution. Run both cover and slide thru the following solutions: 1 part acetic acid to 3 parts absolute alcohol, 1 part acetic acid to 9 parts absolute alcohol, absolute alcohol and finally equal parts of absolute alcohol and xylol. Recombine the cover and slide in xylol-balsam directly from this solution. 相似文献
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Carlo Dani Lucia Giannini Giovanna Bertini Simone Pratesi Iuri Corsini Mariangela Longini 《Free radical research》2013,47(12):1358-1363
The higher risk of respiratory problem in infants delivered by elective caesarean section in comparison with vaginally born infants may be favoured by lower level of nitric oxide (NO) and carbon monoxide (CO) and higher oxidative stress in infants born by caesarean section. We studied healthy term infants born by vaginal delivery or by elective caesarean section. Nitric oxide, CO, guanosine 3–5 cyclic monophosphate, total hydroperoxide and advanced oxidation protein products (AOPP) were measured at birth and 48–72 h of life. Nitric oxide, CO and cGMP were lower at birth and at 48–72 h of life in infants born by elective caesarean delivery. Total hydroperoxide and AOPP levels were similar in the two groups and increased from birth to 48–72 h of life. In conclusion, nitric oxide and CO concentrations were higher in term infants vaginally born than in infants born by elective caesarean section and decreased from birth to 48–72 h of life. The mode of delivery did not affect the oxidative stress which increases from birth to 48–72 h of life. 相似文献
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Clare Bugg Colin Smith Nigel Blackstock David Simpson Paul A. Ashton 《Botanical journal of the Linnean Society. Linnean Society of London》2013,172(3):371-384
The anatomy and morphology of leaves in Carex have the potential to be taxonomically useful. However, studies on the variability of leaf characteristics in the genus are sparse. Researchers therefore risk using leaf anatomical characters without the knowledge of whether they are consistent in a species. We examined 22 qualitative and seven quantitative leaf anatomy characters from transverse leaf sections to test their consistency across 11 Carex spp. The characters were clearly described and primarily microscopic. Some characters were found to exhibit high levels of intraspecific variation, whereas other characters exhibited high levels of consistency in a species, including the shape of the leaf section, the density of papillae and the size of epidermal cells. Caution must be applied when choosing leaf anatomy to delimit taxa because of the intraspecific variability found in some characters, but sufficient numbers of invariant characters exist to provide useful taxonomic separation. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 172 , 371–384. 相似文献
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Contamination of Groundnut in South‐Western Nigeria by Aflatoxigenic Fungi and Aflatoxins in Relation to Processing 下载免费PDF全文
Clement G. Afolabi Chibundu N. Ezekiel Iyabode A. Kehinde Ayodeji W. Olaolu Olaide M. Ogunsanya 《Journal of Phytopathology》2015,163(4):279-286
Groundnut is commonly consumed in its roasted form by many Nigerians. This study was therefore conducted to determine the levels of aflatoxin in roasted groundnut retailed in south‐western Nigeria with a view to assessing the fitness of the processed nut for human consumption. The effects of roasting and de‐coating as alternative methods for reducing the ‘aflatoxin scare’ in the nut were further assessed on aflatoxigenic fungal load and aflatoxin content of the nuts. Forty‐eight samples of retailed raw and roasted groundnut were collected and assessed by mycological and thin‐layer chromatographic analysis for changes in aflatoxigenic fungal population and aflatoxin concentration, respectively. Consequently, 480 isolates of the Aspergillus section Flavi group, A. flavus L strain (n = 410), A. tamarii (n = 56), A. parasiticus (n = 7) and A. parvisclerotigenus (n = 7), were recovered from all samples. Aflatoxigenic isolates of A. flavus L strain (58.8%) had a significantly (P < 0.05) higher incidence than the non‐aflatoxigenic isolates (41.2%). Aflatoxins were detected in 43 (89.6%) of the samples. Approximately 25% of all samples exceeded the 20 ng/g limit for aflatoxin B1 (AFB1) adopted by the National Agency for Food and Drug Administration and Control while 83 and 79% of all samples contained AFB1 and total aflatoxins above the European Union limits of 2 and 4 ng/g, respectively. Aflatoxin concentrations in the raw and coated samples were as much as five times higher than those in the roasted and de‐coated nuts, respectively. However, no significant difference was recorded between aflatoxin levels in the coated and de‐coated samples. This study has shown that roasting of groundnut and testa removal (de‐coating) are effective processing interventions that can significantly lower aflatoxin quantities in the kernels, thus making it fit for human consumption. 相似文献
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Accumulation of the carcinogenic mycotoxin aflatoxin B, has been reported from members of three different groups of Aspergilli (4) Aspergillus flavus, A. flavus var. parvisclerotigenus, A. parasiticus, A. toxicarius, A. nomius, A. pseudotamarii, A. zhaoqingensis, A. bombycis and from the ascomycete genus Petromyces (Aspergillus section Flavi), (2) Emericella astellata and E. venezuelensis from the ascomycete genus Emericella (Aspergillus section Nidulantes) and (3) Aspergillus ochraceoroseus from a new section proposed here: Aspergillus section Ochraceorosei. We here describe a new species, A. rambellii referable to Ochraceorosei, that accumulates very large amounts of sterigmatocystin, 3-O-methylsterigmatocystin and aflatoxin B1, but not any of the other known extrolites produced by members of Aspergillus section Flavi or Nidulantes. G type aflatoxins were only found in some of the species in Aspergillus section Flavi, while the B type aflatoxins are common in all three groups. Based on the cladistic analysis of nucleotide sequences of ITS1 and 2 and 5.8S, it appears that type G aflatoxin producers are paraphyletic and that section Ochraceorosei is a sister group to the sections Flavi, Circumdati and Cervini, with Emericella species being an outgroup to these sister groups. All aflatoxin producing members of section Flavi produce kojic acid and most species, except A. bombycis and A. pseudotamarii, produce aspergillic acid. Species in Flavi, that produce B type aflatoxins, but not G type aflatoxins, often produced cyclopiazonic acid. No strain was found which produce both G type aflatoxins and cyclopiazonic acid. It was confirmed that some strains of A. flavus var. columnaris produce aflatoxin B2, but this extrolite was not detected in the ex type strain of that variety. A. flavus var. parvisclerotigenus is raised to species level based on the specific combination of small sclerotia, profile of extrolites and rDNA sequence differences. A. zhaoqingensis is regarded as a synonym of A. nomius, while A. toxicarius resembles A. parasiticus but differs with at least three base pair differences. At least 10 Aspergillus species can be recognized which are able to biosynthesize aflatoxins, and they are placed in three very different clades. 相似文献
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目的:探讨罗哌卡因腰麻-硬膜外联合麻醉对剖宫产初产妇血清泌乳素水平的影响并评估其安全性。方法:收集我院就诊的90例剖宫产足月单胎初产妇,随机分为实验组和对照组,每组45例。实验组组均采用1%罗哌卡因1.5 mL+生理盐水1.5 mL,对照组产妇给予硬膜外麻醉。术后,比较两组产妇的泌乳素、感觉以及运动阻滞情况、麻醉效果以及不良反应发生率。结果:与手术前相比,两组产妇术后的泌乳素水平升高,且实验组产妇的泌乳素水平显著高于对照组(P0.05)。与对照组相比,实验组产妇感觉阻滞起效时间、运动阻滞起效时间较短,感觉恢复时间以及运动恢复时间较长,麻醉效果较好,不良反应的发生率较低(P0.05)。结论:罗哌卡因腰麻-硬膜外联合麻醉对剖宫产患者血清泌乳素水平的变化影响较硬膜外麻醉小,且麻醉效果及安全性更高。 相似文献
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针对常规石蜡切片方法步骤繁多,耗时长,所用的二甲苯试剂对人体健康有较大毒害性的缺陷,探讨提高制作兔卵巢组织石蜡切片质量的方法。试验从脱水和透明环节进行技术改良,用正丁醇与无水乙醇混合剂取代常规的脱水剂和透明剂。该混合剂具有良好的脱水和透明作用。实验结果表明:通过该技术改良,镜下观察组织结构清晰可辨、颜色鲜艳、对比度好、层次分明,组织切片效果良好。试验改良技术的工艺简单,具有质优、省时、快捷和实用性较好等优点,有推广应用价值。 相似文献