3,167 research outputs found
Fenton-like oxidation of dyes using CoxFe3-xO4 catalyst / Mohammad Khairul Azam Selamat
Get PDFThe cobalt ferrite catalyst were synthesised through the substitution of cobalt into iron oxide matrix via co-precipitation and inverse co-precipitation methods. XRD analysis shown that both catalysts exhibited with cubic spinel phase. No impurity was detected in co-precipitated cobalt ferrite phase. Meanwhile, there is a presence of halide impurity being observed in the inversed co-precipitated catalyst. The FTIR spectrum of co-precipitated cobalt ferrite depicted with higher tetrahedral and octahedral bond substitution compared to inverse co-precipitation catalyst. The particle size of both catalysts were found to be approximately 1.44 ± 0.19 and 1.71 ± 0.28 (xm for co¬precipitation and inverse route, respectively. Interestingly, both catalyst were stable in suspension at neutral pH based on the zeta potential value of -32 mV. The inherent catalytic activity of these catalyst were evaluated based on the degradation of three types of difference dyes. The oxidative degradation of Acid Orange 7 (AO7), Methylene Blue (MB), Rhodamine B (RhB) were performed in the heterogeneous Fenton-like reaction. It was found that different dye behaved differently during the catalysis. AO7 has shown significant removal in both adsorption and catalysis processes; whilst the removal of MB and RhB were negligible. The co-precipitated catalyst shown higher performance in AO7 degradation (66%) compared to inverse co-precipitated catalyst (11%). Such findings suggested that the catalyst synthesised through co-precipitation method was favourable in contrast with the inverse co¬precipitation method
Receiver Windowing Design for Narrowband Interference Mitigation in MB-OFDM UWB System
No full textIn 2005, the WiMedia Alliance working with the European Computer Manufacturers Association (ECMA) announced the establishment of the WiMedia MB-OFDM (Multiband Orthogonal Frequency Division Multiplexing) UWB radio platform as their global UWB standard. It was also chosen as the physical layer (PHY) of high data rate wireless specifications for high speed Wireless USB (W-USB), Bluetooth 3.0 and Wireless High-Definition Media Interface (HDMI). However, due to the low power and wide bandwidth nature of UWB systems, in-band narrowband interference (NBI) may hinder the receiver performance. This thesis presents an analysis of NBI impact on the MB-OFDM system for UWB communication. The intent of our analysis is to provide practical solutions for interference mitigation under different NBI models. In our work, a new receiver windowing for zero padding (ZP) OFDM system is proposed to reduce NBI spreading in the MB-OFDM UWB system. Simulations demonstrate the effectiveness of windowing under different NBI models.Microelectronics & Computer EngineeringElectrical Engineering, Mathematics and Computer Scienc
Altered immunolocalization of FGF23 in murine femora metastasized with human breast carcinoma MDA-MB-231 cells
Get PDFIntroduction After the onset of bone metastasis, tumor cells appear to modify surrounding microenvironments for their benefit, and particularly, the levels of circulating fibroblast growth factor (FGF) 23 in patients with tumors have been highlighted. Materials and methods We have attempted to verify if human breast carcinoma MDA-MB-231 cells metastasized in the long bone of nu/nu mice would synthesize FGF23. Serum concentrations of calcium, phosphate (Pi) and FGF23 were measured in control nu/nu mice, bone-metastasized mice, and mice with mammary gland injected with MDA-MB-231 cells mimicking primary mammary tumors. Results and conclusions MDA-MB-231 cells revealed intense FGF23 reactivity in metastasized lesions, whereas MDA-MB-231 cells cultured in vitro or when injected into the mammary glands (without bone metastasis) showed weak FGF23 immunoreactivity. Although the bone-metastasized MDA-MB-231 cells abundantly synthesized FGF23, osteocytes adjacent to the FGF23-immunopositive tumors, unlike intact osteocytes, showed no FGF23. Despite significantly elevated serum FGF23 levels in bone-metastasized mice, there was no significant decrease in the serum Pi concentration when compared with the intact mice and mice with a mass of MDA-MB-231 cells in mammary glands. The metastasized femora showed increased expression and FGFR1 immunoreactivity in fibroblastic stromal cells, whereas femora of control mice showed no obvious FGFR1 immunoreactivity. Taken together, it seems likely that MDA-MB-231 cells synthesize FGF23 when metastasized to a bone, and thus affect FGFR1-positive stromal cells in the metastasized tumor nest in a paracrine manner
ASIC FFT processor for MB-OFDM UWB system
No full textThe physical layer (PHY) standard of Multi-band Orthogonal Frequency Division Multiplexing (MB-OFDM) Ultra Wideband (UWB) system was defined by ECMA International. In this standard, the data sampling rate from the analog-to-digital converter to the physical layer is up to 528 Msample/s. Therefore, it is a challenge to realize the physical layer of the UWB system-especially the components with high computational complexity in Very Large Scale Integration (VLSI) implementation. Fast Fourier Transform (FFT) block is one of these components. FFT plays an important role in Multi-band OFDM UWB system, which is the demodulation block of OFDM signals. The purpose of this project is to design an Application Specific Integrated Circuit (ASIC) FFT solution for this system. The specification is defined from the system analysis and literature research. All the design choices and considerations are concluded and explained.Based on the algorithm and architecture analysis, a novel Radix22Parallel processor is proposed, which is a small-area and low-power-consumption solution for MB-OFDM UWB system. Both Field Programmable Gate Array (FPGA) and ASIC targeted synthesis results of this architecture are presented.Electrical Engineering, Mathematics and Computer Scienc
Characterization of the tertiary structure of the de novo designed protein MB-1
No full textMilk Bundle-1 (MB-1) is a de novo designed protein with 100 amino acids, having a molecular weight of 11.4 kilodaltons. MB-1 is enriched with 57% of selected essential amino acids (methionine, threonine, lysine and leucine), which are known to be limiting in dairy cattle. Recently, on the basis of a digestibility study, MB-1 was predicted to be unstable in rumen conditions.Characterization of the protein's structure was achieved using fluorescence spectroscopy (steady state measurements). MB-1 contains one tyrosine at position 62, expected to be in position "d" of helix III, in the hydrophobic core. Data obtained using fluorescence quenching indicates that the tyrosine is protected from the solvent in the putative hydrophobic core, as per design.Once it was established that MB-1 was not misfolded, further experiments were done to assess the fluidity of its hydrophobic core. For this, the amphiphillic dye ANSA was used. Results obtained for MB-1 compare favourably to those of many natural proteins, suggesting that MB-1 has achieved some degree of nativeness. Interestingly, MB-1 was found to exclude ANSA from its hydrophobic core more efficiently than all other de novo designed proteins reported to date.Finally, an analysis of folding thermodynamics of MB-1 was attempted. It was found that the fluorescence intensity of tyrosine was not sensitive to unfolding, making thermodynamic data impossible to obtain.Analysis of the data on MB-1 as compared to other natural proteins indicates that MB-1 is folded and compact. The lack of resistance to proteases must be caused by other factors other than the lack of compactness or misfolding. (Abstract shortened by UMI.).Source: Masters Abstracts International, Volume: 36-06, page: 1623.Adviser: Marc Beauregard
Stochastic Lie bracket (derivation, derivation) in MB-algebras
No full textBy a stochastic controller, we make stable the pseudo stochastic Lie bracket (derivation, derivation) in complex MB-algebras. Next, we get an approximation by a stochastic Lie bracket (derivation, derivation) and calculate the maximum error of the estimate. © 2020, The Author(s)
Correction: Screening of strawberry (Fragaria × ananassa Duch.) cultivars for drought tolerance based on physiological and biochemical responses under PEG-induced stress
Get PDFThe Author contributions statement was erroneously given as “ŞA: Data curation, Methodology, Investigation, Writing – original draft. DA: Investigation, Resources, Methodology, Writing – original draft. AA: Writing – original draft. DE: Data curation, Methodology, Writing – original draft, Investigation. ÖB: Writing – original draft, Investigation. BY: Writing – original draft, Investigation. MB: Writing – original draft, Resources. YD: Supervision, Writing – original draft, Investigation. Bİ: Investigation, Writing – original draft. SK: Resources, Writing – review & editing, Visualization. BM: Validation, Supervision, Conceptualization, Writing – original draft, Project administration. NK: Resources, Validation, Project administration, Writing – review & editing, Conceptualization, Supervision.” The correct Author contributions statement is ŞA: Data curation, Methodology, Investigation, Writing – review & editing. DA: Investigation, Resources, Methodology, Writing – review & editing. AA: Data curation, Statistical data analysis, Visualization, Validation, Writing – original draft, Writing – review & editing. DE: Data curation, Methodology, Investigation, Writing – review & editing. ÖB: Investigation, Writing – review & editing. BY: Investigation, Writing – review & editing. MB: Resources, Writing – review & editing. YD: Supervision, Investigation, Writing – review & editing. Bİ: Investigation, Writing – review & editing. SK: Resources, Visualization, Writing – review & editing. BM: Validation, Supervision, Conceptualization, Project administration, Writing – review & editing. NK: Resources, Validation, Project administration, Conceptualization, Supervision, Writing – review & editing. The original version of this article has been updated
Weerkat: An extensible semantic Wiki
No full textWikis are Web applications that blur the boundaries between readers and authors, allowing non-technical people to author hypertexts through a web interface. A Semantic Wiki is a Wiki that attempts the same thing with the Semantic Web, allowing non-technical users to create semantic resources and/or ontologies. In this paper we characterise the different ways in which a Wiki might support the Semantic Web and present Weerkat, a modular and extensible Wiki that has ontological hypertext support. Key to this has been the design and development of a highly flexible Wiki architecture which allows easy modification and augmentation of functionality
The Efficacy and Mechanism of Action of HDAC Inhibitors in Triple Negative Breast Cancer
Get PDFHistone deacetylase inhibitors (HDACis) are a class of chemically heterogeneous anticancer agents which consist of a hydrophobic capping group, linker region, and Zn 2+ chelating pharmacophore. Manipulation of these three regions, such as the incorporation of a pyridine capping group, and hydroxythiopyridone Zn 2+ binding group has yielded Jazz-90, and M1S and M2S, respectively. Alongside vorinostat, these HDACis were tested for their cytotoxicity and activity in triple negative MDA-MB-231 and MDA-MB-468 breast cancer cells. The novel compound Jazz-90 displayed the greatest cytotoxic potency in MDA-MB-231 cells (EC 50 1.14 μM) while M1S had an EC 50 of 1.66 μM in MDA-MB-468 cells. Time-course cytotoxicity studies showed the compounds to have a cytostatic effect at the EC 50 concentration (1X) and a cytotoxic effect at four-fold the EC 50 concentration (4X). Furthermore, the effect on protein expression was determined using Western blotting at 24 h post-treatment. Relative to their cytotoxicity, the EC 50 of vorinostat (2.10 μM) showed the greatest increase in acetylated histone-H3 protein expression followed by 1X Jazz-90, 1472% and 1041%, respectively, compared to control in MDA-MB-231 cells; a similar trend was seen in MDA- MB-468 cells. Compared to vehicle control, only 4X of M1S (6.66 μM) and M2S (17.17 μM) significantly increased acetylated histone-H3 expression in MDA-MB-468 cells, 11404% and 10795%, respectively. Cell cycle protein analysis revealed that compared to control 1X of vorinostat, M1S, and M2S significantly downregulated cyclin B1 expression in MDA-MB-231 cells by 56%, 65%, and 29%, respectively, suggesting the compounds to induce G 2 /M-phase arrest. Interestingly, 1X of M1S and M2S were found to significantly increase cyclin D1 expression in MDA-MB-231 cells by 122% and 97%, respectively, suggesting that the compounds promote progression through the G 1 -phase. No change in total cyclin E2, Hsp90, or NF-κB p65 protein expression was seen in either cell line, p53 in MDA-MB-231 cells, or nuclear Hsp90 and nuclear NF-κB p65 in MDA-MB-468 cells. Thus, our findings provide evidence of the cytotoxic potency of Jazz-90, M1S, and M2S, but limited HDAC inhibitory effects in TNBC cells in vitro, hence warranting further modulation of the capping and Zn 2+ binding moieties to enhance their HDAC inhibitory profile
Analysis of Safe and Effective Next-Generation Rail Signalling Systems using a FTA-SAN Approach
No full textMoving Block (MB) and Virtual Coupling (VC) rail signalling will change current train operation paradigm by migrating vital equipment from trackside to onboard to reduce train separation and maintenance costs. Their actual deployment is however constrained by the industry’s need to identify configurations of MB and VC signalling equipment which can effectively guarantee safe train movements even under degraded operational conditions involving component faults. In this paper, we analyse the effectivity of MB and VC in safely supervising train separation under nominal and degraded conditions by using an innovative approach which combines Fault Tree Analysis (FTA) and Stochastic Activity Network (SAN). A FTA model of unsafe train movement is defined for both MB and VC capturing functional interactions and cause effect relations among the different signalling components. The FTA is then used as a basis to apportion signalling component failure rates needed to feed the SAN model. Effective MB and VC train supervision is analysed by means of SAN-based simulations in the specific scenario of an error in the Train Position Reporting (TPR) for five rail market segments featuring different traffic characteristics, namely high-speed, mainline, regional, urban and freight. Results show that the overall approach can support infrastructure managers, railway undertakings, and rail system suppliers in investigating effectiveness of MB and VC in safely supervising train movements in scenarios involving different types of degraded conditions and failure events. The proposed method can hence support the railway industry in identifying effective and safe design configurations of next-generation rail signalling systems.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Transport and Plannin
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