110 research outputs found

    Liquid core fibre Bragg grating based refractive index sensor formed by femtosecond assisted chemical etching technique

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    We report the fabrication of a refractive index (RI) sensor based on a liquid core fibre Bragg grating (FBG). A micro-slot FBG was created in standard telecom optical fibre employing the tightly focused femtosecond laser inscription aided chemical etching. A micro-slot with dimensions of 5.74(h) × 125(w) × 1388.72(l) μm was engraved across the whole fibre and along 1mm long FBG which gives advantage of a relatively robust liquid core waveguide. The device performed the refractive index sensitivity up to about 742.72 nm/RIU

    Pegylation of Nanoliposomal Paclitaxel Enhances its Efficacy in Breast Cancer

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    Purpose: To encapsulate paclitaxel into nanoliposomes, followed by  pegylatation, in order to improve its therapeutic index and reduce side effects in breast cancer.Methods: In order to prepare nanoliposomal paclitaxel, varying ratios of phosphatidylcholine, cholesterol and paclitaxel were mixed and the formulations pegylated with poly-ethylene glycol 2000 (PEG 2000) to  enhance stability, efficiency, as well as solubility. The mean diameter of nanoliposomal paclitaxel and pegylated nanoliposomal paclitaxel were measured by Zeta sizer device and release of paclitaxel from both  formulations was determined within 28 h by dialysis method. The  cytotoxicity of nanoliposomal and pegylated nanoliposomal paclitaxel was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.Results: The mean diameter of nanoliposomal paclitaxel and pegylated nanoliposomal paclitaxel was 421.4 and 369.1 nm, respectively, while encapsulation efficiency was 91.3 ± 5.7 and 95.2 ± 6.3 %, respectively. Paclitaxel released from both formulations in 28 h was 5.53 and 5.02 %, respectively. The cytotoxicity of pegylated nanoliposomal paclitaxel was significantly (p . 0.05) greater than that of nanoliposomal paclitaxel (their IC50 = 79.8±2.9 and 86.25±3.4 µg/ml, respectively).Conclusion: The release pattern and cytotoxicity of pegylated  nanoliposomal paclitaxel show that the formulation is superior to  nanoliposomal paclitaxel. Furthermore, the mean particle size of pegylatednanoliposome is smaller than that of the non-pegylated preparation.Keywords: Paclitaxel, Nanoliposome, Breast cancer, Pegylation, Drug delivery, Cytotoxicit

    Progression of sleep disturbances in Parkinson’s Disease. A 5-year longitudinal study.

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    BACKGROUND: Sleep disorders can occur in early Parkinson’s disease (PD). However, the relationship between different sleep disturbances and their longitudinal evolution has not been fully explored. OBJECTIVE: To describe the frequency, coexistence and longitudinal change in excessive daytime sleepiness (EDS), insomnia and probable REM sleep behaviour disorder (pRBD) in early PD. METHODS: Data were obtained from the Parkinson’s Progression Markers Initiative (PPMI). EDS, insomnia, and pRBD were defined using the Epworth Sleepiness Scale, MDS-UPDRS Part I sub-item 1.7, and RBD screening questionnaire. RESULTS: 218 PD subjects and 102 controls completed five years of follow up. At baseline, 69 (31.7%) PD subjects reported one type of sleep disturbance, 25 (11.5%) reported two types of sleep disturbances, and three (1.4%) reported all three types of sleep disturbances. At five years, the number of PD subjects reporting one, two and three types of sleep disturbances was 85 (39.0%), 51 (23.4%), and 16 (7.3%), respectively. Only 41(18.8%) patients were taking sleep medications. The largest increase in frequency was seen in insomnia (44.5%), followed by EDS (32.1%) and pRBD (31.2%). Insomnia was the most common sleep problem at any time over the 5-year follow-up. The frequency of sleep disturbances in HCs remained stable. CONCLUSIONS: There is a progressive increase in the frequency of sleep disturbances in PD, with the number of subjects reporting multiple sleep disturbances increasing over time. Relatively few patients reported multiple sleep disturbances, suggesting that they can have different pathogenesis. A large number of patients were not treated for their sleep disturbances

    Improvement in the Production of L-Lysine by Overexpression of Aspartokinase (ASK) in C. glutamicum ATCC 21799

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    Purpose: To clone Corynebacterium glutamicum ATCC21799 aspartokinase gene (EC 2.7.2.4) using shuttle expression vector pEKEx2 in order to increase lysine production.Methods: C. glutamicum DNA was extracted and used for amplification of aspartokinase gene (ask) by cloning into an E. coli/C. glutamicum shuttle expression vector, pEKEx2. Initially, the recombinant vector transformed into E. coli DH5á and then into C. glutamicum.Results: Electrophoresis of recombinant protein by SDS-PAGE showed that the molecular weight of the recombinant protein was 42 KD. The induction of recombinant vector by IPTG had an inhibitory effect on cell growth due to over-expression of the cloned gene. The results of lysine assay by Chinard method showed that lysine production increased about two-fold, compared with the parent strain, as a result of increased copy numbers of lysC gene in recombinant strain.Conclusion: A two-fold increase in lysine production was observed by cloning of the ASK gene in C. glutamicum rather than in E. coli, due to the presence of lysine exporter channel which facilitates lysine extraction.Keywords: LysC gene, Corynebacterium glutamicum, L- lysine, Cloning, Aspartokinase, E. col

    Cognitive load during planned and unplanned virtual shopping: Evidence from a neurophysiological perspective

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    Rapid adoption of virtual-reality-assisted retail applications is inadvertently reshaping consumer buying patterns, making it crucial for businesses to enhance their shopping experience. This new scenario challenges marketers with unique hurdles in both the commercialization of products and in managing information cues derived via VR retailing. Therefore, this study examined consumers’ impulsive behavior and unplanned purchases in a virtual retail store, using self-reports and electroencephalography. Borrowing assorted perspectives from retailing, virtual reality, and neuromarketing literature, we extended the stimulus-organism-response framework to evaluate how unplanned behavior evolves through conscious and unconscious measures. We found that consumers’ impulsiveness was significantly associated with their unplanned expenditure and the number of unplanned purchases. Using mediation analysis, we observed that flow experience during shopping partially mediated the relationship between the sense of presence and the desire to stay longer in a virtual shopping store. Desire to stay in the virtual store positively influenced store satisfaction, basket-size deviation, and budget deviation. Additionally, cognitive workload obtained via electroencephalogram revealed significant differences during both planned and unplanned purchases. These findings provide fresh opportunities for retailers to leverage the disruptive potential of immersive and interactive virtual technology to transform consumer shopping experiences

    f(R) theories

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    Over the past decade, f(R) theories have been extensively studied as one of the simplest modifications to General Relativity. In this article we review various applications of f(R) theories to cosmology and gravity - such as inflation, dark energy, local gravity constraints, cosmological perturbations, and spherically symmetric solutions in weak and strong gravitational backgrounds. We present a number of ways to distinguish those theories from General Relativity observationally and experimentally. We also discuss the extension to other modified gravity theories such as Brans-Dicke theory and Gauss-Bonnet gravity, and address models that can satisfy both cosmological and local gravity constraints.Comment: 156 pages, 14 figures, Invited review article in Living Reviews in Relativity, Published version, Comments are welcom

    Prediction of Protein Domain with mRMR Feature Selection and Analysis

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    The domains are the structural and functional units of proteins. With the avalanche of protein sequences generated in the postgenomic age, it is highly desired to develop effective methods for predicting the protein domains according to the sequences information alone, so as to facilitate the structure prediction of proteins and speed up their functional annotation. However, although many efforts have been made in this regard, prediction of protein domains from the sequence information still remains a challenging and elusive problem. Here, a new method was developed by combing the techniques of RF (random forest), mRMR (maximum relevance minimum redundancy), and IFS (incremental feature selection), as well as by incorporating the features of physicochemical and biochemical properties, sequence conservation, residual disorder, secondary structure, and solvent accessibility. The overall success rate achieved by the new method on an independent dataset was around 73%, which was about 28–40% higher than those by the existing method on the same benchmark dataset. Furthermore, it was revealed by an in-depth analysis that the features of evolution, codon diversity, electrostatic charge, and disorder played more important roles than the others in predicting protein domains, quite consistent with experimental observations. It is anticipated that the new method may become a high-throughput tool in annotating protein domains, or may, at the very least, play a complementary role to the existing domain prediction methods, and that the findings about the key features with high impacts to the domain prediction might provide useful insights or clues for further experimental investigations in this area. Finally, it has not escaped our notice that the current approach can also be utilized to study protein signal peptides, B-cell epitopes, HIV protease cleavage sites, among many other important topics in protein science and biomedicine

    Editors’ Introduction: An Overview of the Educational Administration and Leadership Curriculum: Traditions of Islamic Educational Administration and Leadership in Higher Education

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    This chapter provides an overview of several topics relevant to constructing an approach to teaching educational administration and leadership in Muslim countries. First, it places the topic in the context of the changing nature and critiques of the field that argue for a greater internationalisation to both resist some of the negative aspects of globalisation and to represent countries’ traditions in the professional curriculum. Then, it identifies literature that presents the underlying principles and values of Islamic education that guide curriculum and pedagogy and shape its administration and leadership including the Qur’an and Sunnah and the classical educational literature which focuses on aims, values and goals of education as well as character development upon which a ‘good’ society is built. This is followed by a section on the Islamic administration and leadership traditions that are relevant to education, including the values of educational organisations and how they should be administered, identifying literature on the distinctive Islamic traditions of leadership and administrator education and training as it applies to education from the establishment of Islam and early classical scholars and senior administrators in the medieval period who laid a strong foundation for a highly sophisticated preparation and practice of administration in philosophical writings and the Mirrors of Princes writings, and subsequent authors who have built upon it up to the contemporary period. The final section provides an overview of the chapters in this collection
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