排序方式： 共有33条查询结果，搜索用时 15 毫秒
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Bakhshali Massoumi Raana Sarvari Amir Zareh Younes Beygi-Khosrowshahi Samira Agbolaghi 《Fibers and Polymers》2018,19(10):2157-2168
The main objective of this work was chemically bioactivation of the conducting polyanizidine (PANIZ) by incorporating a polyester such as polycaprolactone (PCL). Modified PANIZ nanocomposites were synthesized through ring opening and chemical oxidation polymerizations. A four-point probe was applied to measure the conductivity of newly synthesized star-like block copolymer (S-PCL-PANIZ) nanocomposite, which was about 0.44 S cm-1. Conductive biodegradable nanofibers were prepared by electrospinning with 25 and 75 % (wt/wt) S-PCL-PANIZ to PCL. The contact angle of each prepared nanofiber was 87±3°, supporting their usefulness for cell culture. The cultured mouse osteoblast MG63 cells demonstrated normal morphology and significantly higher adhesion and spreading on the nanofiber. The bioactivated PANIZ based nanocomposite may be fruitful in tissue engineering to fabricate conducting biodegradable scaffolds with improved cell adhesion properties for various cell cultures. 相似文献
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The cytotoxicity of extracts obtained from plants occurring in the Amazon and Atlantic rain forests against NCI-H460, KM-12, SF-268 and RPMI-8226 cancer cell lines was investigated. Expressive activity was observed in the extracts of Toulicia cf. pulvinata, Ampirrhox sp., Macoubea sprucei, Calophyllum brasiliense, Vismia guianensis, Caryocar microcarpum, Xylopia aromatica and Distictella magnoliifolia. 相似文献
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Adel Jalili Younes Asri Shahbaz Yazdani Fatemeh Zarrinkamar Reza Safavi John G Hodgson Ken Thompson Mojtaba Pakparvar 《Biological conservation》2003,109(3):425-431
The Arasbaran Protected Area is an important but little studied nature reserve in NW Iran. In the past habitat heterogeneity and biodiversity have been threatened by over-exploitation; in the future depopulation may lead to partial abandonment. The soil seed bank was examined to see whether there are sufficient species represented as persistent seeds to reconstitute the vegetation in the event of habitat deterioration. There were differences between seed banks from different soils and vegetation types but essentially all soil seed banks contained few species and low densities of seed. Moreover, the species in the seed bank were unrepresentative of the vegetation. During future periods of changing land use it will be important to maintain the existing vegetation. There are however indications of successful recent conservation management. Annuals are abundant in the woodland seed bank but absent from the vegetation. The forest is recovering from the disturbance of collecting fire-wood. 相似文献
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Modeling reactive transport with chemical equilibrium reactions requires solution of coupled partial differential and algebraic equations. In this work, two formulations are developed to combine the method of lines (MOL) with the global implicit approach. The first formulation has a non-conservative form and leads to a nonlinear system of ordinary differential equations with a reduced number of unknowns. The second formulation presents better conservation properties but leads to a nonlinear system of differential algebraic equations with a large number of unknowns. In both formulations, the resulting systems are integrated in time using the DLSODIS time solver which adapts both the order of the time integration and the time step size to provide the necessary accuracy. Numerical experiments show that higher-order time integration is effective for solving the non-conservative formulation and point out the high benefit of the MOL for solving reactive transport problems. 相似文献
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Mohammadi Azadeh Niazi Ali Aram Farzaneh Hassani Farshid Ghasemi Younes 《Journal of Crop Science and Biotechnology》2020,23(1):81-88
Journal of Crop Science and Biotechnology - Nowadays, transgenic plants are considered as an expression system for therapeutic recombinant proteins. One of the approaches to recombinant protein... 相似文献
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以野生型岷江百合（Lilium regale Wilson）为材料,克隆岷江百合蛋白激酶基因lilyABC1,分析其在非生物胁迫下的表达特性,为百合抗逆育种提供候选基因。结果表明：lilyABC1基因全长cDNA序列为2 333 bp,其开放阅读框（ORF）为2 007 bp。该基因编码668个氨基酸,预测lilyABC1蛋白分子量为74.84 kD,等电点为5.46,含有一个高度保守的结构域--STYKc。lilyABC1基因在岷江百合的叶片、鳞片、花蕾组织中均有表达,表达量依次为叶 > 花蕾 > 鳞片,其中不同时期的花蕾中的表达量基本一致。lilyABC1的表达受到NaCl、低温、高温以及黑暗胁迫的诱导,对PEG-6000的模拟干旱处理不敏感,表明lilyABC1基因可能对岷江百合适应高盐、低温和黑暗等非生物胁迫具有一定作用。 相似文献
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比较了耐盐碱的岷江百合（Lilium regale Wilson）和对盐碱敏感的东方百合‘索邦’（‘Sorbonne’）在不同浓度的碱性盐NaHCO3胁迫下叶片的渗透调节物质、活性氧清除物质、离子调节物质（Na+、K+）及有机酸含量的变化,探讨百合耐盐碱的生理机制。研究发现,两种百合叶片中各种物质的变化趋势基本相似,但整体上岷江百合的各种物质含量或者活性均高于‘索邦’。随着NaHCO3胁迫浓度的增加,两种百合叶片中的可溶性蛋白、脯氨酸含量增加,可溶性糖含量先升后降;SOD、GR的活性和AsA的含量先上升后下降,APX的活性和GSH的含量在低浓度胁迫时无明显变化,高浓度胁迫时显著下降;‘索邦’Na+主要积累在成熟叶和新生叶中,岷江百合则主要积累在茎和成熟叶中,且能维持根、成熟叶和新生叶中较高水平的K+/Na+值;岷江百合中的草酸、乳酸和乙酸含量都一直增加或高于对照,‘索邦’中的苹果酸和乙酸含量一直增加。与‘索邦’相比,岷江百合在低浓度NaHCO3胁迫下提高SOD活性和AsA含量,高浓度NaHCO3胁迫下增加可溶性蛋白的含量并保持可溶性糖的稳定性,是其耐盐碱性较强的原因之一。 相似文献
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Fatemeh Nejatzadeh-Barandozi Mohammad Reza NaghaviSattar Tahmasebi Enferadi Amir MousaviYounes Mostofi Mohammad Esmaiel Hassani 《Industrial Crops and Products》2012,37(1):347-351
In this study, genetic diversity of 10 accessions of Aloe vera, collected from different parts of Iran, were evaluated using horticultural and random amplified polymorphic DNA (RAPD) data. Statistical analysis showed significant differences for all horticultural characteristics among the accessions, suggesting that selection for relevant characteristics could be possible. The analysis of molecular diversity was used the RAPD technique, with 10 random primers of 10-mer oligonucleotides. Out of the 10 primers, five were polymorphic, producing 269 DNA bands, 189 of which were polymorphic among accessions. A dendrogram was prepared on the basis of a similarity matrix using the Unweighted Pair Group Method Arithmetic Mean (UPGMA) algorithm, separating the 10 accessions into two groups. Results show that both environmental and genetic factors are effective in observing variations. Our results also indicate that the RAPD approach, along with horticultural analysis, seemed to be best-suited for assessing with high accuracy the genetic relationships among distinct A. vera accessions. 相似文献
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Montiel L Tremblay A Girard V Chorfi Y 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2007,36(3):278-280
BACKGROUND: Hypophosphatemia is a condition that affects feed intake and milk production in dairy cows, and, to assess it, a precise biological parameter is needed. Plasma inorganic phosphate (Pi) can be used as a potential indicator of bioavailability of feed phosphorus in dairy cows. OBJECTIVE: The purpose of this study was to evaluate the effects of sample type (serum vs. plasma), blood sampling site (jugular vs. coccygeal), and morning feeding on blood Pi concentration in dairy cows. METHODS: Blood samples from 28 clinically healthy multiparous Holstein cows were analyzed for Pi concentration. The animals were sampled twice by coccygeal vessel into Vacutainer tubes both with and without sodium heparin, 3 hours after the morning feeding. In 4 additional cows, the concentration of Pi was measured in blood samples obtained simultaneously by jugular and coccygeal venipuncture into heparinized tubes before the morning feeding and 2, 4, and 6 hours after the feeding. The results were analyzed using parametric statistical tests. RESULTS: Serum and plasma concentrations of Pi were correlated (r(2) = 0.999, P < .0001), but serum Pi concentration was higher than plasma Pi (P < .02). Plasma Pi concentration 2 hours after feeding tended to be higher than that before feeding in jugular samples, but the difference was not significant. There was no significant variation in plasma Pi during the morning postfeeding times, although jugular concentrations were 19% lower than coccygeal (P = .04). CONCLUSION: To increase the precision of plasma Pi measurements as an indicator of bioavailability of feed phosphorus, sample type, sampling time, and site must be taken into account, to correctly interpret plasma Pi concentrations. 相似文献