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排序方式: 共有333条查询结果,搜索用时 62 毫秒
321.
Sumera Khizar Hamdi Ben Halima Nasir M. Ahmad Nadia Zine Abdelhamid Errachid Abdelhamid Elaissari 《Electrophoresis》2020,41(13-14):1206-1224
Superparamagnetic nanoparticles are attracting significant attention. Therefore, being explored in microsystems for a wide range of applications. Typical examples include lab-on-a-chip and microfluidics for synthesis, detection, separation, and transportation of different bioanalytes, such as biomolecules, cells, and viruses to develop portable, sensitive, and cost-effective biosensing systems. Particularly, microfluidic systems incorporated with magnetic nanoparticles and, in combination with magnetoresistive sensors, shift diagnostic and analytical methods to a microscale level. In this context, nanotechnology enables the miniaturization and integration of a variety of analytical functions in a single chip for manipulation, detection, and recognition of bioanalytes reliably and flexibly. In consideration of the above, recent development and benefits are elaborated herein to discuss the role of magnetic nanoparticles inside the microchannels to design highly efficient disposable point-of-care applications from transportation to the detection of bioanalytes. 相似文献
322.
Amna M. Abdella Amr M. Abdelmoniem Ismail A. Abdelhamid Ahmed H. M. Elwahy 《Journal of heterocyclic chemistry》2020,57(4):1476-1523
Heterocycles represent the largest diversity of organic compounds with signifcant chemical, biomedical, and industrial applications. They exist in numerous natural products, dyes, and as scaffolds in diverse drugs and related pharmaceutically active substances. Substantial attention has been paid to develop various elegant methods to synthesize heterocycles. Among different strategies, Michael and Hantzsch reactions are considered as effective approaches for construction of heterocycles and their corresponding fused derivatives. This review covers this area especially in the last 10 years. The heterocyclic systems reported in this review are classified according to the kind of the heterocyclic systems. 相似文献
323.
Said A. S. Ghozlan Ismail A. Abdelhamid Hamdi M. Hassaneen Mohamed H. Elnagdi 《Journal of heterocyclic chemistry》2007,44(1):105-108
1‐Arylhydrazonopyruvaldehydes 1 react with α,β‐unsaturated nitriles 2 to yield 6‐amino‐1,4‐dihydropyridazines 4 that are converted into pyridazinones 5 via refluxing in an acetic acid/hydrochloric acid mixture and into the ethylidenemalononitrile derivatives 6 on reflux with malononitrile in ethanolic/piperidine solution. 相似文献
324.
Pyrimido[2“,1”:5′,6′]pyrazolo[3′,4′:4,5]‐pyrimido[1,6‐a]benzoimidazoloe‐2,8(1H,7H)‐diones, and [1,2,4]‐triazino‐[3“,4”:5′,6′]pyrazolo[3′,4′:4,5]pyrimido[1,6‐a]benzimidazol‐8(7H)‐ones were synthesized in a good yields via 1‐amino‐4‐methyl‐3,4‐dihydro‐5H‐pyrazolo[3′,4′:4,5]pyrimido[1,6‐a]benzoimidazolo‐5‐one and the appropriate active methylene compounds. Structures of the newly synthesized compounds were elucidated on the basis of elemental analyses, spectral data, and alternative synthesis methods whenever possible. 相似文献
325.
This paper continues the study of a kernel family which uses the Cauchy–Stieltjes kernel 1/(1−θ
x) in place of the celebrated exponential kernel exp (θ
x) of the exponential families theory. We extend the theory to cover generating measures with support that is unbounded on
one side. We illustrate the need for such an extension by showing that cubic pseudo-variance functions correspond to free-infinitely
divisible laws without the first moment. We also determine the domain of means, advancing the understanding of Cauchy–Stieltjes
kernel families also for compactly supported generating measures. 相似文献
326.
Nasri N Tlili N Elfalleh W Cherif E Ferchichi A Khaldi A Triki S 《Natural product research》2011,25(18):1733-1742
Natural chemical compounds are a widely researched topic worldwide because of their potential activity against cerebrovascular diseases. Chemicals from Juniperus phoenicea berries are reported in this study. Lipids (11%) from seeds are mainly unsaturated (86%). Minerals are also quantified like Na (63.8?mg per 100?g?DW) or K (373.9?mg per 100?g?DW). Total reduced sugars are ca 192.6?mg?g(-1)?DW. Polyphenols and flavonoids from berries are highly present with an average of 1764?±?174.3?mg gallic acid per 100?g?DW and 890?±?47.6?mg rutin per 100?g?DW, respectively. Mean free radical scavenging activities, determined by DPPH and ABTS, are 1337?±?126.2?mM TEAC per 100?g?DW and 1105.7?±?95.9?mM TEAC per 100?g?DW, respectively. All findings improve the possible presence of biologically active fractions in phytocomplex that could be used as such and/or extracted for the formulation of supplements and/or ingredients for the pharmaceutical industry. 相似文献
327.
Abdou O. Abdelhamid Ahmed H. Elghandour Nora A. Rateb Ahmed M. Awad 《Phosphorus, sulfur, and silicon and the related elements》2013,188(7):1637-1646
1-amino-4-methyl-4H-3-thia-4,5a,10-triazacyclopenta-[a]fluoren-5-one and 6-methyl-6H-,9H-thia-4b,6,9,11,12-pentaazaindeno[1,2-a]-fluorene-5,8-dione derivatives were prepared from 2-methyl-1-oxo-3-thioxo-2,4,9b-trihydropyrimidino[1,6-a] benzimidazole-4-carbonitrile. Also, 2,3-dihydro-1,3,4-thidazoles were synthesized via a reaction of hydrazonoyl chlorides with 3-(methylamino)-2-substituted 3-thioxopropanenitrile. Structures of newly synthesized compounds were elucidated on the basis of elemental analyses, spectral data, and alternative methods synthesis whenever possible. 相似文献
328.
Abdou O. Abdelhamid Ali A. Al-Atoom 《Phosphorus, sulfur, and silicon and the related elements》2013,188(7):1629-1646
Abstract Thiazolylacetonitrile was used in the synthesis of coumarin, pyrazolo[4,3]pyrimidines, 1,3,4-thiadiazolines, aminothiophenes, and thiazoles in a good yields. Also, pyrazolo[4,5-d]triazolino[4,5-a]pyrimidines, pyrazolo[4,5-d]thiazolino[3,2-a]pyrimidines, and pyrazolo[4,5-d]tetrazolino[1,5-a]pyrimidines were synthesized from pyrazolo[4,5-d]pyrimidine. Structures of the newly synthesized were elucidated by elemental analysis, spectral data, and alternative synthesis routes whenever possible. Some synthesized compounds were tested for their antimicrobial activity. 相似文献
329.
Abdou O. Abdelhamid Ahmed H. Elghandour Ahmed M. Hussein Yasser H. Zaki 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):2097-2109
Triazoles, thiadiazoles, and triazolo[4, 3-a]pyrimidines were synthesized via reaction of hydrazonoyl halides with each of 3-methyl-4-(methylthiothioxomethyl)-2-pyrazolin-5-one, 3-methyl-4-[methylthio(phenylamino)methyl]-2-pyrazolin-5-one, and pyrimidine-2-thiones. Structures of the newly synthesized compounds were elucidated on the basis of elemental analysis, spectral data, and alternative-methods synthesis whenever possible. 相似文献
330.
Samia Yahyaoui Rached Ben Hassen Vaclav Petí
ek Michal Duek Abdelhamid Ben Salah 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(3):i24-i26
The ternary system SrBr2–CdBr2–H2O was investigated at room temperature. The title phase, SrCd2Br6·8H2O, has been isolated from this system and its structure determined by single‐crystal X‐ray diffraction. The structure consists of infinite double chains of CdBr6 octahedra and chains of Sr(H2O)9 polyhedra packed along the b axis. The interaction between these two isolated chains occurs through O—H⃛O and O—H⃛Br hydrogen bonds. The structure is compared with that of SrCd2Cl6·8H2O. 相似文献