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排序方式: 共有183条查询结果,搜索用时 187 毫秒
61.
Mustafa Germec Fadime Demirel Nurullah Tas Ali Ozcan Cansu Yilmazer Zeynep Onuk Irfan Turhan 《Cellulose (London, England)》2017,24(10):4337-4353
Microwave-assisted pretreatment can be used for fermentable sugar production from lignocellulosic biomass. In this study, the optimum hydrolysis conditions of barley husk, oat husk, wheat bran, and rye bran were determined in power level, treatment time, solid-to-liquid ratio and dilute acid ratio as follows: 700 W, 6.92 min, 1:18.26 w/v, and 3.67% for barley husk, 600 W, 6.96 min, 1:17.22 w/v, and 3.47% for oat husk, 600 W, 6.92 min, 1:16.69 w/v, and 1.85% for wheat bran, and 460 W, 6.15 min, 1:17.14 w/v, and 2.72% for rye bran. The fermentable sugar concentrations were 37.21 (0.68 g/g), 38.84 (0.67 g/g), 49.65 (0.83 g/g), and 36.27 g/L (0.62 g/g) under optimum conditions, respectively. The results showed that microwave-assisted pretreatment is a promising technology which can be successfully implemented for the hydrolysis of lignocellulosic biomass for high sugar yield. On the other hand, hydrolysates included some inhibitors such as organic acids, furans, and phenolic compounds. Lignocellulosic biomass used in this study can be employed as good feedstocks for value-added product production in the fermentation process, after the inhibitors have been detoxified/removed with different detoxification methods. 相似文献
62.
The sensitive capillary electrophoretic‐LIF method for simultaneous determination of curcuminoids in turmeric by enhancing fluorescence intensities of molecules upon inclusion into (2‐hydroxypropyl)‐β‐cyclodextrin
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Zeynep Kalaycıoğlu Parya Hashemi Keriman Günaydın F. Bedia Erim 《Electrophoresis》2015,36(20):2516-2521
Curcuminoids have received great attention in the past decades due to their health benefit properties. The aim of this study is to develop a very simple, rapid, and sensitive capillary zone electrophoresis technique coupled with a laser induced fluorescence detector (LIF) for the simultaneous determination of three major curcuminoids of turmeric, namely, curcumin, demethoxy curcumin (DMC), and bisdemethoxy curcumin (BDMC). Background electrolyte was selected as borate at pH 9.6 and (2‐hydroxypropyl)‐β‐cyclodextrin (2‐HP‐β‐CD) was added to prevent rapid alkali degradation of curcuminoids in buffer and to increase fluorescence intensities of molecules. With the addition of 2‐HP‐β‐CD to the separation electrolyte, the fluorescence signal intensities of curcuminoids were enhanced considerably by 30, 40, and 54 fold for curcumin, DMC, and BDMC, respectively. The three curcuminoids of turmeric were fully separated and quantified in less than 4.5 min. The repeatability of the peak areas of curcuminoids for intra‐day and inter‐day experiments was in the satisfactory range of 2.26 and 2.55%, respectively. The LOD and LOQ values for the developed method were equal to or less than 0.081 and 0.270 μg/mL, respectively, for all curcuminoids. The developed method was successfully applied to find curcuminoids amount in turmeric samples and herbal supplements. 相似文献
63.
Kyle A. Brown Trisha Tucholski Christian Eken Samantha Knott Yanlong Zhu Prof. Song Jin Prof. Ying Ge 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(22):8484-8488
Mass spectrometry (MS)-based proteomics provides unprecedented opportunities for understanding the structure and function of proteins in complex biological systems; however, protein solubility and sample preparation before MS remain a bottleneck preventing high-throughput proteomics. Herein, we report a high-throughput bottom-up proteomic method enabled by a newly developed MS-compatible photocleavable surfactant, 4-hexylphenylazosulfonate (Azo) that facilitates robust protein extraction, rapid enzymatic digestion (30 min compared to overnight), and subsequent MS-analysis following UV degradation. Moreover, we developed an Azo-aided bottom-up method for analysis of integral membrane proteins, which are key drug targets and are generally underrepresented in global proteomic studies. Furthermore, we demonstrated the ability of Azo to serve as an “all-in-one” MS-compatible surfactant for both top-down and bottom-up proteomics, with streamlined workflows for high-throughput proteomics amenable to clinical applications. 相似文献
64.
We report the MR appearance of undifferentiated (embryonal) sarcoma of the liver (USL) in a 13-year-old female who presented with a 1-year history of intermittent abdominal pain, weight loss, and fatigue. The tumor was a large, solitary, well-defined focal mass lesion with multiple cystic spaces, septations, and substantial central necrosis. 相似文献
65.
The stochastic transportation problem with single sourcing 总被引:1,自引:0,他引:1
We propose a branch-and-price algorithm for solving a class of stochastic transportation problems with single-sourcing constraints. Our approach allows for general demand distributions, nonlinear cost structures, and capacity expansion opportunities. The pricing problem is a knapsack problem with variable item sizes and concave costs that is interesting in its own right. We perform an extensive set of computational experiments illustrating the efficacy of our approach. In addition, we study the cost of the single-sourcing constraints. 相似文献
66.
Senem Şanli İsmail M. Palabiyik Nurullah Şanli Zeynep B. Guzel-Seydim Güleren Alsancak 《Journal of Analytical Chemistry》2011,66(9):838-847
The simple, rapid and sensitive liquid chromatographic separation of five macrolides (tilmicosin, erythromycin, tylosin, roxithromycin
and josamycin) widely used in food producing animals was developed. Response surface methodology was used as an optimization
method of mobile phase, column temperature and pH to provide the best resolution of these analytes. The separation was performed
by using an end-capped X-Terra RP-18 column (250 × 4.6 mm I.D × 5 m) with an isocratic system of 15 mM hydrochloric acid (pH
2.5)-acetonitrile as the mobile phase at a temperature of 30°C and flow-rate of 1.0 mL/min. The suitability of the method
for multi-residue determination of the macrolides is demonstrated by the analysis of milk samples spiked with tylosin. Roxithromycin
was used as internal standard. The recovery of tylosin was quite good as 90.8%. The limit of quantification and detection
limit were 0.024 and 0.007 μg/mL, respectively. The method was successfully applied to determination of macrolides at levels
below the maximum concentration legally allowed in milk samples. 相似文献
67.
Development of surface chemistry for surface plasmon resonance based sensors for the detection of proteins and DNA molecules 总被引:1,自引:0,他引:1
The immobilisation of biological recognition elements onto a sensor chip surface is a crucial step for the construction of biosensors. While some of the optical biosensors utilise silicon dioxide as the sensor surface, most of the biosensor surfaces are coated with metals for transduction of the signal. Biological recognition elements such as proteins can be adsorbed spontaneously on metal or silicon dioxide substrates but this may denature the molecule and can result in either activity reduction or loss. Self assembled monolayers (SAMs) provide an effective method to protect the biological recognition elements from the sensor surface, thereby providing ligand immobilisation that enables the repeated binding and regeneration cycles to be performed without losing the immobilised ligand, as well as additionally helping to minimise non-specific adsorption. Therefore, in this study different surface chemistries were constructed on SPR sensor chips to investigate protein and DNA immobilisation on Au surfaces. A cysteamine surface and 1%, 10% and 100% mercaptoundecanoic acid (MUDA) coatings with or without dendrimer modification were utilised to construct the various sensor surfaces used in this investigation. A higher response was obtained for NeutrAvidin immobilisation on dendrimer modified surfaces compared to MUDA and cysteamine layers, however, protein or DNA capture responses on the immobilised NeutrAvidin did not show a similar higher response when dendrimer modified surfaces were used. 相似文献
68.
69.
Journal of Thermal Analysis and Calorimetry - Tobacco waste is one of the main industrial agricultural wastes. In this study, potential of pyrolysis process for valorization of this type of biomass... 相似文献
70.
Zeynep Aydo?mu? 《Journal of fluorescence》2009,19(4):673-679
A new, simple and sensitive spectrofluorimetric method has been developed for the determination of oseltamivir phosphate (OSP)
in capsules. The method is based on the reaction between oseltamivir and fluorescamine in borate buffer solution of pH 8.50
to give highly fluorescent derivatives that are measured at 483 nm using an excitation wavelength of 381. The different experimental
parameters effecting the development and stability of the reaction product were carefully studied and optimized. The fluorescence
intensity concentration plot is rectilinear over the range 50–450 ng mL−1 with a lower detection limit (LOD) of 1.219 ng mL−1 and limit of quantitation (LOQ) of 4.064 ng mL−1. Selectivity was validated by subjecting stock solution of OSP to acidic, basic, oxidative, and thermal degradation. No interference
was observed from excipients present in formulations. The developed method was successfully applied to determination of the
drug in capsules. The mean % recovery (n = 6) was 100.08. The results obtained were in good agreement with those obtained using a reported spectrophotometric method. 相似文献