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71.
Untreated paired helical filaments (PHFs) and pronase-digested PHF-core filaments were stereoscopically imaged with a freeze-drying vertical platinum-carbon replication preparation method for TEM. The untreated PHF have an average wide region (W) = 22.8 +/- 2.4 nm, a narrow region (T) = 10.6 +/- 1.7 nm, and a helical turn period (L) = 78.6 +/- 13.4. The surfaces of the untreated PHF's fuzzy coat appears disorganized. The widths of the pronase-treated PHF-core filaments were significantly reduced (W(d) = 14.8 +/- 1.2 nm, T(d) = 5.7 +/- 1.0 nm, and L(d) = 75.4 +/- 17 nm). The surfaces of the untreated PHF contained approximately 1.1 nm strands, the same size as tau monomer ( approximately 1.0 nm). The pronase-digested PHF cores mostly contained approximately 1.6 +/- 0.3 nm strands although strand diameters ranged from 0.6-2.5 nm. The strands sometimes appear to be wrapped around the filament axis; less often, they appear to be roughly parallel to the PHF axis, and otherwise appear to be randomly oriented. Images of pronase-digested PHF core images are discussed in relation to the core's biochemical composition, its proposed beta structure, and structural subunit models. Images of the untreated and the pronase-digested PHF support a helical ribbon morphology. 相似文献
72.
Khalid Al-Anezi Chris Somerfield David Mee Nick Hankins Nidal Hilal 《Desalination》2008,227(1-3):46-56
The objective of this work is to present experimental data that would show the effect of temperature, salinity, pressure and the presence of anti-scale additives on CO2 solubility in seawater. The paper examines the solubility of CO2 in real seawater and real seawater dosed with two different anti-scale additives. The study has been performed at temperatures between 60ºC and 90ºC and at pressures of 1 and 2 bar. To assess the effect of each anti-scale additive on CO2 gas solubility varying doses, 2–10 ppm of anti-scale additive have been used. For the purpose of the experimentation an experimental rig has been designed to ensure adequate contact between the gas phase and the aqueous phase. The continuous quantitative analysis of CO2 concentration flowing from the experimental rig was measured using a CM-5011 Carbon Coulometer. A mass balance was carried out to calculate the amount of CO2 absorbed into solution; Henry’s law constant was then calculated. 相似文献
73.
The influences of the exchange complex and pH of the solution used for cation saturation on Atterberg limits, compaction, and swelling potential of a compacted clay were investigated. The study involved transforming the exchange complex from a heterogeneous to a homogeneous one so that a frame of reference can be set for the clay behavior under such an ideal condition. The employed method for altering the exchange complex successfully yielded homo-ionic clay. The introduction of different species of cations gave rise to different particles associations. When introduced to the tested clay, potassium cations bond its particles with a rather strong bond (K-linkage), causing a drastic decrease in the specific area of the clay (about one-fourth of its untreated specific area), a decrease in the CEC, as well as a drastic decrease in the swell potential. For example, the swell pressure decreased from 1.87 kg/cm2 for the untreated samples to 0.4 kg/cm2 for the K-treated samples (under the same conditions). Also, the swell potential vs. time relationships can be modeled accurately using a rectangular hyperbola. 相似文献
74.
The surface properties of Ti-6Al-4V alloy, such as wear resistance, are inadequate for many applications. To improve the surface properties of the alloy, many techniques have been considered. One of the promising techniques is to form a nitride layer on the surface of the workpiece by a laser beam. In the present study, laser assisted nitriding of the Ti-6Al-4V alloy surface is carried out under a nitrogen gas flow environment. A CO2 laser is used to irradiate the Ti-6Al-4V alloy surface while nitrogen is introduced co-axially with the laser beam onto the workpiece surface. The resulting surface cross section is examined metallurgically. SEM and XRD were carried out for material characterization. The study is extended to include the electrochemical response of the resulting surfaces. The surface morphology of the electrochemically treated workpieces are examined. It is found that in the laser treated region dendritic structures occur and TiN forms in the surface vicinity. The density of pit formation at the surface of the treated region reduces considerably. 相似文献
75.
Industry 4.0 is a buzzword in current research and in the manufacturing environment. However, despite this limited research has focused on how a company can determine the likely benefits of Industry 4.0 technologies and its influence on the supply chain. Additionally, the aspect of customer experience is gaining significant importance in the new Industry 4.0 supply chain. There is a research gap in implementation strategies of Industry 4.0 concepts for small and medium sized enterprises (SMEs). This paper addresses this gap through an in-depth case study of an SME and highlights how the company can develop competitive advantage. First, a framework was developed to determine the realization of Industry 4.0 predicted benefits for SMEs, which was tested in a case company. Based on input from the case the five-step framework for Industry 4.0 realization is adjusted. It enables practitioners to determine the actual status for their company towards Industry 4.0 realization and thereby functions as a guide for further implementation strategies. 相似文献
76.
Mohammad A. Khanfar Diaa T. A. Youssef Prof. Khalid A. El Sayed Prof. 《ChemMedChem》2010,5(2):274-285
The microfilament cytoskeleton protein actin plays an important role in cell biology and affects cytokinesis, morphogenesis, and cell migration. These functions usually fail and become abnormal in cancer cells. The marine‐derived macrolides latrunculins A and B, from the Red Sea sponge Negombata magnifica, are known to reversibly bind actin monomers, forming 1:1 stoichiometric complexes with G‐actin, disrupting its polymerization. To identify novel therapeutic agents for effective treatment of metastatic breast cancer, several semisynthetic derivatives of latrunculin A with diverse steric, electrostatic, and hydrogen bond donor and acceptor properties were rationally prepared. Analogues were designed to modulate the binding affinity toward G‐actin. Examples of these reactions are esterification, acetylation, and N‐alkylation. Semisynthetic latrunculins were then tested for their ability to inhibit pyrene‐conjugated actin polymerization, and subsequently assayed for their antiproliferative and anti‐invasive properties against MCF7 and MDA‐MB‐231 cells using MTT and invasion assays, respectively. 相似文献
77.
Parul Singh Arun Rawat Bara Al-Jarrah Saras Saraswathi Hoda Gad Mamoun Elawad Khalid Hussain Mohammed A. Hendaus Wesam Al-Masri Rayaz A. Malik Souhaila Al Khodor Anthony K. Akobeng 《International journal of molecular sciences》2021,22(4)
Coeliac disease (CD) and Type 1 diabetes mellitus (T1DM) are immune-mediated diseases. Emerging evidence suggests that dysbiosis in the gut microbiome plays a role in the pathogenesis of both diseases and may also be associated with the development of neuropathy. The primary goal in this cross-sectional pilot study was to identify whether there are distinct gut microbiota alterations in children with CD (n = 19), T1DM (n = 18) and both CD and T1DM (n = 9) compared to healthy controls (n = 12). Our second goal was to explore the relationship between neuropathy (corneal nerve fiber damage) and the gut microbiome composition. Microbiota composition was determined by 16S rRNA gene sequencing. Corneal confocal microscopy was used to determine nerve fiber damage. There was a significant difference in the overall microbial diversity between the four groups with healthy controls having a greater microbial diversity as compared to the patients. The abundance of pathogenic proteobacteria Shigella and E. coli were significantly higher in CD patients. Differential abundance analysis showed that several bacterial amplicon sequence variants (ASVs) distinguished CD from T1DM. The tissue transglutaminase antibody correlated significantly with a decrease in gut microbial diversity. Furthermore, the Bacteroidetes phylum, specifically the genus Parabacteroides was significantly correlated with corneal nerve fiber loss in the subjects with neuropathic damage belonging to the diseased groups. We conclude that disease-specific gut microbial features traceable down to the ASV level distinguish children with CD from T1DM and specific gut microbial signatures may be associated with small fiber neuropathy. Further research on the mechanisms linking altered microbial diversity with neuropathy are warranted. 相似文献
78.
Mahmoud M. A. Nassar Khalid I. Alzebdeh Tasneem Pervez Nasr Al-Hinai Abdul Munam 《应用聚合物科学杂志》2021,138(43):51284
Owing to economic and environmental benefits, new generations of materials/commodities follow “from waste to wealth” strategy. Recently, there has been a huge upsurge in research on the development of eco-composites using recycled plastic polymers and agro-residues because the eco-composites satisfy the stringent environment regulations and are cost-effective. Herein, we present a detailed review on the potential use of several types of natural fillers as an efficient reinforcement for recycled plastic polymers. In particular, the characterization of different categories of eco-composites according to their morphological, physical, thermal, and mechanical properties is extensively reviewed and their results are analyzed, compared, and highlighted. Furthermore, a framework to produce functional eco-composites, which includes functionalization of ingredients, critical issues on microstructural parameters, processing, and fabrication methods, is outlined and supported with sufficient data from the literature. Finally, the review outlines the emerging challenges and future prospects of eco-composites to be addressed by interested researchers to bridge the gap between research and commercialization of such a class of material. Overall, the acquired knowledge will guide researchers, scientists, and manufacturers to plan, select, and develop various forms of eco-composites with enhanced properties and optimized production processes. 相似文献
79.
Rajivgandhi Govindan Nadar Chenthis Kanisha Chelliah Vijayakumar Sekar Alharbi Naiyf S. Kadaikunnan Shine Khaled Jamal M. Alanzi Khalid F. Li Wen-Jun 《Journal of Inorganic and Organometallic Polymers and Materials》2021,31(10):3921-3933
Journal of Inorganic and Organometallic Polymers and Materials - The silver oxide nanoparticle was successfully synthesized using floral waste by simple one pot, cost effective method. The complete... 相似文献
80.
S.S. Choudhari S.R. Wadgane Bharatratna P. Gaikwad S.S. Satpute Khalid Mujasam Batoo Omar M. Aldossary Sagar E. Shirsath R.H. Kadam 《Ceramics International》2021,47(5):6496-6504
Materials with magneto-electric (ME) properties are of great importance because of their demand in electronic industries. Three dimensional nano-particles of the ME-composites having the general formula (1-x)CoCr0.3Fe1.7O4(CCFO)+(x)BaTiO3(BTO) (x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) were obtained by comprising the piezoelectric-BTO and piezomagnetic-CCFO phases. The individual phases of CCFO and BTO were synthesized separately by ultrasonic irradiation assisted sonochemical and sol-gel routs. X-ray diffraction patterns (XRD) confirmed the well-crystalline nature of both the phases. BTO and CCFO phases were under tensile strain as confirmed by the variation in lattice constants with varying proportion of BTO and CCFO. An energy-dispersive X-ray spectroscopy spectrum confirmed the phase purity of the samples and stoichiometric concentration of elements. Magnetic properties were investigated by M ? H loop measurements and dielectric properties by using RF impedance analyzer. Dielectric constant increased with the increasing percentage of BTO. The maximum value of ME coefficient (24.7 mV/cm?Oe) is observed for the 60%CCFO+40%BTO sample. The obtained results were discussed in the light of grain size, strain and the basic properties of the individual phases. The prepared materials can be applicable in electronic devices where high magneto-electric coefficient is desirable. 相似文献