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排序方式: 共有982条查询结果,搜索用时 15 毫秒
31.
Mohamed N. Aboul-Enein Aida A. El-Azzouny Mohamed I. Attia Yousreya A. Maklad Mona E. Aboutabl Fatma Ragab Walaa H. A. Abd El-Hamid 《International journal of molecular sciences》2014,15(9):16911-16935
Synthesis and anticonvulsant potential of certain new 6-aryl-9-substituted-6,9-diazaspiro[4.5]decane-8,10-diones (6a–l) and 1-aryl-4-substituted-1,4-diazaspiro[5.5]undecane-3,5-diones (6m–x) are reported. The intermediates 1-[(aryl)(cyanomethyl)amino]cycloalkanecarboxamides (3a–f) were prepared via adopting Strecker synthesis on the proper cycloalkanone followed by partial hydrolysis of the obtained nitrile functionality and subsequent N-cyanomethylation. Compounds 3a–f were subjected to complete nitrile hydrolysis to give the respective carboxylic acid derivatives 4a–f which were cyclized under mild conditions to give the spiro compounds 5a–f. Ultimately, compounds 5a–f were alkylated or aralkylated to give the target compounds 6a–i and 6m–u. On the other hand, compounds 6j–l and 6v–x were synthesized from the intermediates 5a–f through alkylation, dehydration and finally tetrazole ring formation. Anticonvulsant screening of the target compounds 6a–x revealed that compound 6g showed an ED50 of 0.0043 mmol/kg in the scPTZ screen, being about 14 and 214 fold more potent than the reference drugs, Phenobarbital (ED50 = 0.06 mmol/kg) and Ethosuximide (ED50 = 0.92 mmol/kg), respectively. Compound 6e exhibited an ED50 of 0.019 mmol/kg, being about 1.8 fold more potent than that of the reference drug, Diphenylhydantoin (ED50 = 0.034 mmol/kg) in the MES screen. Interestingly, all the test compounds 6a–x did not show any minimal motor impairment at the maximum administered dose in the neurotoxicity screen. 相似文献
32.
Synthetic Modular Antibody Construction by Using the SpyTag/SpyCatcher Protein-Ligase System
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Dr. Md Kausar Alam Carolina Gonzalez Wayne Hill Dr. Ayman El-Sayed Dr. Humphrey Fonge Dr. Kris Barreto Prof. Dr. C. Ronald Geyer 《Chembiochem : a European journal of chemical biology》2017,18(22):2217-2221
Efforts to engineer recombinant antibodies for specific diagnostic and therapy applications are time consuming and expensive, as each new recombinant antibody needs to be optimized for expression, stability, bio-distribution, and pharmacokinetics. We have developed a new way to construct recombinant antibody-like “devices” by using a bottom-up approach to build them from well-behaved discrete recombinant antibody domains or “parts”. Studies on antibody structure and function have identified antibody constant and variable domains with specific functions that can be expressed in isolation. We used the SpyTag/SpyCatcher protein ligase to join these parts together, thereby creating devices with desired properties based on summed properties of parts and in configurations that cannot be obtained by using genetic engineering. This strategy will create optimized recombinant antibody devices at reduced costs and with shortened development times. 相似文献
33.
A. Harmouch H. Haddad A. El-Sayed Ahmad 《Journal of Communications Technology and Electronics》2016,61(8):957-962
Conventional slotted waveguide antennas are well known and prominently used for many military and even marketable applications. This is due to their different advantageous electrical and mechanical characteristics. It is also well known that this type of antennas is a typical array of slots with which the width of the main beam can be controlled in only one plane by using a different number of elements in such antennas. Numerous research, discuss the capability of using an array of such antennas in order to narrow down the main beam in both planes and even achieve a scanning phased array. In this paper, a new and broader approach is presented concerning beam width control of the typical configuration of such antennas. This work presents the ability to control the main lobe in both planes using only one slotted waveguide to a certain extent. Different simulation results are considered at the 2.4 GHz frequency demonstrating improved effectiveness in terms of directivity and high gain as well as minimizing the side-lobe level and mechanically controlling the main lobe of the antenna. 相似文献
34.
Sibel Duman Bülent Kaya Fatma Caf Barış Enez Sema Aguloğlu Fincan 《International Journal of Hydrogen Energy》2021,46(29):15410-15430
For the first time in this innovative study, microorganisms such as Bacillus simplex bacteria, mostly used in biological activity studies, are used as a bio-supporter agent of iron to release hydrogen from sodium borohydride hydrolysis at 25.0 ± 0.1 °C. The goal is to investigate thoroughly sodium borohydride hydrolysis catalyzed by Fe2O3 nanoparticles impregnated on microorganism such as Bacillus simplex (BS) bacteria (Fe2O3@BS NPs) known with strong antibacterial properties, which makes innovative them a candidate for hydrolysis reaction. This study was focused on the preparation, identification, and catalytic use of biocatalyst-like Fe2O3@BS NPs for hydrogen release from the sodium borohydride hydrolysis at 25.0 ± 0.1 °C. The characterization results made after and before hydrolysis reaction using by SEM/SEM-EDX, FT-IR, XRD, UV–vis, XPS, DLS, ELS Zeta potential, ESR, and TEM techniques reveal the formation of highly active, stable, durable, and long-lived biocatalysts-like Fe2O3@BS NPs. 相似文献
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36.
Investigating the effect of production process of ball mill refiner on some physical quality parameters of compound chocolate: response surface methodology approach
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Omer Said Toker Fatma Tugce Zorlucan Nevzat Konar Orhan Dağlıoğlu Osman Sagdic Dilek Şener 《International Journal of Food Science & Technology》2017,52(3):788-799
Chocolate compound was produced using ball mill refiner, and the effect of agitator shaft speed and refining time on the physical quality parameters (particle size, colour and steady‐state rheology) of compound chocolate was determined using response surface methodology. The shaft speed and refining time range were selected between 40–60 r.p.m. and 10–30 min, respectively. Determination coefficient of the models established for particle size, Newtonian viscosity and colour parameters (brightness, chroma and hue angle) were found to be very close to unity. Increasing shaft speed and time induced a reduction in particle size and an increase in viscosity of the samples. Temperature sweep test was also performed, and the obtained data were successfully fitted to Arrhenius equation to calculate the corresponding parameters representing temperature dependency of the compounds. The results highlighted that the establishment of such models can provide essential information in terms of optimisation of production processes regarding usage purpose of the compound chocolate. 相似文献
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A method was developed for separation, preconcentration, and determination of La by its radioactive isotope 138La using an HPGe detector. The method was checked by comparison with ICP-MS. The detection limit (minimum detection activity) is 1.46 and 1.52 Bq kg?1 at 788.4 and 1435.8 keV lines, respectively. The Th(IV) and U(VI) are separated by precipitation. To separate Ac(III), it is extracted jointly with REEs from 0.1 M HNO3 with HDEHP and then stripped with 0.2 M HNO3, with REEs remaining in the organic phase. Lanthanum in a mixture with REEs is determined by ??-ray spectrometry. 相似文献
40.
Decade inductance boxes are widely used in electrical laboratories for calibration of instruments that measure inductance. The main aim of this paper is to construct a new inductance box providing a huge number of automated inductance steps, which are used in the laboratories to perform full automatic calibration of inductance meters. Therefore, a new inductance box has been introduced that mainly consists of three decades. The three inductance decades have the same design, but each has its four different internal inductive elements. Each decade can generate 15 different inductance values, so it is more economical and practical compared to the other ordinary decades, which produce only 10 values by using 10 internal inductive elements. 1666 different inductance values can be obtained from this inductance box, while 4096 inductance values can be obtained by the possible combinations of its three decades steps. Practical design, fabrication and specifications of this new inductance box are demonstrated in detail. It is designed to achieve relative accuracy in the range from 5 × 10?4 to 5 × 10?3. It could be used to perform full automatic inductance measurements at the National Institute of Standards, Egypt, for the first time. Comparison between an ordinary inductance box and the new introduced one has been made to validate its performance. 相似文献