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排序方式: 共有213条查询结果,搜索用时 31 毫秒
71.
A conducting molecularly imprinted polymer (CMIP) film, based on polypyrrole, was electrosynthesized for selective uptake/release and determination of naproxen. The film was prepared by incorporation of a template anion (naproxen) during the electropolymerization of pyrrole into a platinum electrode using the cyclic voltammetry method. Overoxidized polypyrrole films with cavities complementary to the template were used as a potential-induced selective recognition element in the solid-phase sorbent. Various important fabricating factors, which control the performance of the CMIP film, were investigated using fluorescence spectroscopy. The measured fluorescence intensities of released solutions were related to the concentrations of naproxen taken up into the films. Several key parameters such as applied potential and time for uptake and release were varied to achieve the optimal sorption procedure. The film template with naproxen exhibited excellent selectivity over some interference. The calibration graphs were linear in the ranges of 5×10(-8) to 3×10(-7)molml(-1) and 7×10(-6) to 8×10(-4)molml(-1), and the limit of detection was 1×10(-8)molml(-1). The CMIP films, as the electrochemically controlled solid-phase sorbent, were applied for the selective cleanup and quantification of trace amounts of naproxen from physiological samples. Scanning electron microscopy confirmed the nanostructure morphology of the films. 相似文献
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73.
Recent process improvements for the ammonia fiber expansion (AFEX) process and resulting reductions in minimum ethanol selling price 总被引:2,自引:0,他引:2
Sendich EN Laser M Kim S Alizadeh H Laureano-Perez L Dale B Lynd L 《Bioresource technology》2008,99(17):8429-8435
The ammonia fiber expansion (AFEX) process has been shown to be an effective pretreatment for lignocellulosic biomass. Technological advances in AFEX have been made since previous cost estimates were developed for this process. Recent research has enabled lower overall ammonia requirements, reduced ammonia concentrations, and reduced enzyme loadings while still maintaining high conversions of glucan and xylan to monomeric sugars. A new ammonia recovery approach has also been developed. Capital and operating costs for the AFEX process, as part of an overall biorefining system producing fuel ethanol from biomass have been developed based on these new research results. These new cost estimates are presented and compared to previous estimates. Two biological processing options within the overall biorefinery are also compared, namely consolidated bioprocessing (CBP) and enzymatic hydrolysis followed by fermentation. Using updated parameters and ammonia recovery configurations, the cost of ethanol production utilizing AFEX is calculated. These calculations indicate that the minimum ethanol selling price (MESP) has been reduced from $1.41/gal to $0.81/gal. 相似文献
74.
Fusarium graminearum trichothecene producing isolates can be broadly divided into two chemotypes based on the production of the 8- ketotrichothecenes deoxynivalenol (DON) and nivalenol (NIV). Functional Tri13 gene required for the production of NIV and 4- acetyl NIV, whereas in the isolates producing DON and its acetylated derivates, this gene is nonfunctional. In this study, a total of 57 isolates from different fields of Mazandaran province, Iran were identified as F. graminearum using classical methods and species specific primers. In order to assess the potential of isolates to produce NIV or DON, we used PCR to determine whether isolates carried a functional or nonfunctional Tri13 gene. Out of the 57 tested F. graminearum isolates with Tri13 PCR assays, 46 yielded an amplicon similar to the size predicted for nivalenol production, while 11 yielded an amplicon similar to the size predicted for deoxynivalenol production. From regions where more than one F. graminearum isolate was obtained, isolates were not exclusively of a single chemotype. It seems that genetic diversity among the isolates has relation with geographical region and wheat cultivar. The assay can provide information about the distribution of Tri13 haplotype that can be used in tracing of trichothecene contaminated samples. 相似文献
75.
Hassan Sadri AliReza Alizadeh Hani Vakili Ali Ghorbani Rupert M. Bruckmaier Anna Artati Jerzy Adamski Helga Sauerwein 《Metabolomics : Official journal of the Metabolomic Society》2017,13(3):28
Introduction
Cinnamon exerts insulin-enhancing activity in vitro and was demonstrated to improve blood glucose and lipid profiles in several human studies. Such effects may have an impact on metabolically stressed cows.Objective
To study the effects of cinnamon supplementation during the transition from late pregnancy to early lactation on the metabolism in dairy cows.Methods
Twenty-four Holstein cows (n?=?8/group) were assigned to either the control group (CTR; without supplementation) or the supplementation groups [supplemental cinnamon at 20 (LCIN) or 40 (HCIN) g/cow per day (d)] from 28 d before calving until 21 d thereafter. Blood samples were assayed for glucose, nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHBA), and insulin; an index estimating insulin sensitivity (RQUICKI) was calculated. The serum metabolome was characterized in the samples collected from d 14 using a non-targeted approach.Results
The serum concentrations of glucose and insulin did not differ among groups and followed a similar pattern over time. The serum NEFA concentrations were greater in LCIN (d 2, 7, and 14) and HCIN (d 14) than in CTR. On d 14 and 21, LCIN and HCIN had greater serum BHBA concentrations than CTR cows. The top 10 metabolites identified with significantly higher levels in the supplemented than the CTR cows were related to fatty acid metabolism.Conclusion
The data suggest lipolytic and ketogenic effects of cinnamon supplementation in dairy cows during the transition from late gestation to early lactation. The fatty acid metabolites found elevated in the supplemented cows point towards impaired mitochondrial fatty acid β-oxidation.76.
Vahid Zijah Roya Salehi Marziyeh Aghazadeh Mohammad Samiei Effat Alizadeh Soodabeh Davaran 《In vitro cellular & developmental biology. Animal》2017,53(6):502-512
Tissue engineering has emerged as a potential therapeutic option for dental problems in recent years. One of the policies in tissue engineering is to use both scaffolds and additive factors for enhancing cell responses. This study aims to evaluate and compare the effect of three types of biofactors on poly-caprolactone-poly-ethylene glycol-poly caprolactone (PCL-PEG-PCL) nanofibrous scaffold on human dental pulp stem cell (hDPSCs) engineering. The PCL-PEG-PCL copolymer was synthesized with ring opening polymerization method, and its nanofiber scaffold was prepared by electrospinning method. Nanofibrous scaffold-seeded hDPSCs were treated with sodium fluoride (NaF), melanocyte-stimulating hormone (MSH), or simvastatin (SIM). Non-treated nanofiber seeded cells were utilized as control. The viability, biocompatibility, adhesion, proliferation rate, morphology, osteo/odontogenic potential, and the expression of tissue-specific genes were studied. The results showed that significant higher results demonstrated significant higher adhesive behavior, viability, alizarin red activity, and dentin specific gene expression in MSH- and SIM-treated cells (p < 0.05). This study is unique; in that, it compares the effects of different treatments for optimization of dental tissue engineering. 相似文献
77.
Occurrence of arbuscular mycorrhizal fungi in saline soils of the Tabriz Plain of Iran in relation to some physical and chemical properties of soil 总被引:10,自引:0,他引:10
The abundance and distribution of arbuscular mycorrhizal fungi (AMF) were evaluated in the Tabriz Plain, where soil salinity levels range from 7.3 to 92.0 dS/m. Soil and root samples were collected from the rhizosphere of several glycophytes (Allium cepa L., Medicago sativa L., Triticum aestivum L. and Hordeum vulgare L.) and halophytes (Salicornia sp. and Salsola sp.) and were analysed for spore number in soil, root colonization with AMF and some physical and chemical soil properties. The number of AMF spores was not correlated significantly with soil salinity but suffered adverse effects from the accumulation of some anions and cations. Cluster analysis of correlation matrices showed that root colonization, soil pH, sand and clay percent, and soil-available P, rather than soil salinity and ion concentrations, were closely related with spore number. The percentage of root length colonized in glycophytes significantly decreased with increasing soil salinity. Barley roots showed 5% mycorrhizal colonization in high soil salinity (~20 dS/m). Halophyte roots were not mycorrhizal but more spores were found in rhizosphere than in non-rhizosphere soil. 相似文献
78.
79.
80.
Electrochemical studies of DNA immobilization onto the azide-terminated monolayers and its interaction with taxol 总被引:2,自引:0,他引:2
Mehdinia A Habib Kazemi S Zahra Bathaie S Alizadeh A Shamsipur M Mousavi MF 《Analytical biochemistry》2008,375(2):331-338
A surface modification procedure for the creation of self-assembled monolayers (SAMs) that can be used as a scaffold for double-stranded DNA (dsDNA) incorporation onto the gold surfaces is described. The SAMs of an azidohexane thiol derivative were prepared on the Au electrode and then used for the immobilization of dsDNA. The electrochemical characteristics of dsDNA onto the SAM-modified gold electrode were investigated by cyclic voltammetry and electrochemical impedance spectroscopy, and the surface concentration of dsDNA onto the SAMs surface was estimated. The interaction of dsDNA with the anticancer drug, taxol (paclitaxel), was also studied on the surface of DNA/SAM/Au electrode. The observed decrease in the guanine oxidation peak current was used to monitor the interaction of taxol with DNA. The resulting Langmuir isotherm for taxol binding to DNA at the modified electrode was used to evaluate the binding constant of taxol-DNA. The results obtained supported the groove binding interaction of taxol with DNA. The modified electrode was used as a sensitive sensor for quantification of taxol in human serum sample. 相似文献