237 research outputs found

    A novel diblock copolymer of (monomethoxy poly [ethylene glycol]-oleate) with a small hydrophobic fraction to make stable micelles/polymersomes for curcumin delivery to cancer cells

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    Curcumin is a potent natural anticancer agent, but its effectiveness is limited by properties such as very low solubility, high rate of degradation, and low rate of absorption of its hydrophobic molecules in vivo. To date, various nanocarriers have been used to improve the bioavailability of this hydrophobic biomaterial. This study investigates the encapsulation of curcumin in a novel nanostructure of monomethoxy poly(ethylene glycol)-oleate (mPEG-OA) and its anticancer effect. Tests were done to determine the critical micelle concentration (CMC), encapsulation efficiency, drug-loading efficiency, and cytotoxicity (against U87MG brain carcinoma cells and HFSF-PI3 cells as normal human fibroblasts) of some nanodevice preparations. The results of fluorescence microscopy and cell-cycle analyses indicated that the in vitro bioavailability of the encapsulated curcumin was significantly greater than that of free curcumin. Cytotoxicity evaluations showed that half maximal inhibitory concentrations of free curcumin and curcumin-loaded mPEG-OA for the U87MG cancer cell line were 48 μM and 24 μM, respectively. The Annexin-V-FLUOS assay was used to quantify the apoptotic effect of the prepared nanostructures. Apoptosis induction was observed in a dose-dependent manner after curcumin-loaded mPEG-OA treatments. Two common self-assembling structures, micelles and polymersomes, were observed by atomic force microscopy and dynamic light scat­tering, and the abundance of each structure was dependent on the concentration of the diblock copolymer. The mPEG-OA micelles had a very low CMC (13.24 μM or 0.03 g/L). Moreover, atomic force microscopy and dynamic light scattering showed that the curcumin-loaded mPEG-OA polymersomes had very stable structures, and at concentrations 1,000 times less than the CMC, at which the micelles disappear, polymersomes were the dominant structures in the dispersion with a reduced size distribution below 150 nm. Overall, the results from these tests revealed that this nanocarrier can be considered as an appropriate drug delivery system for delivering curcumin to cancer cells. © 2014 Erfani-Moghadam et al

    Use of single-chain antibody derivatives for targeted drug delivery

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    Single-chain antibodies (scFvs), which contain only the variable domains of full-length antibodies, are relatively small molecules that can be used for selective drug delivery. In this review, we discuss how scFvs help improve the specificity and efficiency of drugs. Small interfering RNA (siRNA) delivery using scFv-drug fusion peptides, siRNA delivery using scFv-conjugated nanoparticles, targeted delivery using scFv-viral peptide-fusion proteins, use of scFv in fusion with cell-penetrating peptides for effective targeted drug delivery, scFv-mediated targeted delivery of inorganic nanoparticles, scFv-mediated increase of tumor killing activity of granulocytes, use of scFv for tumor imaging, site-directed conjugation of scFv molecules to drug carrier systems, use of scFv to relieve pain and use of scFv for increasing drug loading efficiency are among the topics that are discussed here. © 2016, University of Michigan. All rights reserved

    Social media adoption framework for aged care service providers in Australia

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    © 2017 IEEE. The aged care sector has been a late adopter of social media platforms for communicating, collaborating, marketing and creating brand awareness. There is little research that examines the adoption of social media by aged care service providers for these purposes. This paper reviews the status of social media adoption in the Australian aged care industry, to understand in what ways social media can serve older people's needs, and to develop recommendations for aged-care service providers to adopt social media applications to empower older people. Through a review of the literature and interviews with Australian experts, this paper suggests aged care providers use a three-phase framework when adopting social media in the aged care sector. The first phase is to adopt a popular public social media platform such as Facebook followed by Instagram and Twitter. The second phase supports interaction by encouraging posts and feedback by locally hosted member forums. The third phase is the adoption of specialised social applications for closed groups and specific functions. The paper concludes with a discussion on the implications of the framework and proposes directions for future research

    High prevalence of extended-spectrum β-lactamase (blaCTX-M-15) and New Delhi metallo-β-lactamase-1 (NDM-1) genes among high-level carbapenem resistance Klebsiella pneumonia: an alarm for our health system

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    Background: The extended-spectrum β-lactamase (ESBL) carbapenems-resistant Klebsiella isolates are considered one of the most significant challenging in the treatment of patients in hospitals. The aim of this study was to determine the prevalence of important carbapenem resistance genes ESBL subtypes and between K. pneumoniae from patients at hospital in Tehran, Iran.Methods: Fifty-four isolates of K. pneumoniae were isolated from Shariatee Hospital in Tehran from February 2013 to July 2016. Antibiotic testing was done by using the standard disk diffusion method and E-test MIC. The confirmation of carbapenemase activity was performed using an MHT and a new method called the carbapenem inactivation method test (CIM). Finally, a polymerase chain reaction (PCR) and sequencing of related genes was performed.Results: Our PCR data demonstrate that blaCTX-M group’s 40 (81.4%) genes were the most prevalent in our hospital followed by group genes blaCTX-M-3 (18.51%) and blaCTX-M-2 (20.38%). The distribution of the CTX-M group revealed that blaCTX-M-15 23 (42.6%) was the dominant subtype. The coexistence of multiple genes included blaTEM, CTX-M and blaSHV, and CTX-M The presence of blaNDM1, blaOXA-48, and blaKPC were identified in the carbapenem-resistant isolates, 22 (40.7%), 10 (18.5%), and 7 (12.9%) respectively.Conclusion: Our research showed that a CIM test for the first time in Iran is possible and has a high facility for the fast identification of carbapenem-resistant Klebsiella (CRK). We are encountered with the emergence of CTX-M, OXA-48, KPC, and NDM1 harboring CRK strains in our hospitals. Therefore, the treatment of patients infected with these isolates will be an important future concern in our clinical settings.Running Head: Resistance genes among carbapenem-resistant Klebsiella pneumoniaKeywords: New Delhi metallo-beta-lactamase-1, Klebsiella pneumoniae, Carbapenem, Extended-spectrum ß-lactamas

    Prevalence of Gram-negative bacteria in ventilator-associated pneumonia in neonatal intensive care units: A systematic review and meta-analysis protocol

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    Introduction: Ventilator-associated pneumonia (VAP) is a common and potentially lethal problem among mechanically ventilated neonates in neonatal intensive care units (NICUs). The main pathogenic bacteria of VAP in NICUs are Gram-negative pathogens, which show a general decline in sensitivities to commonly used antibiotics, but their true prevalence is not known. Methods and analysis: We aim to provide a systematic review of studies measuring the prevalence of Gram-negative bacteria in VAP in NICUs. We will search PubMed, SCOPUS, EMBASE and the ISI Web of Science, as well as the Google Scholar search engine with no restriction on language. Full copies of articles will be identified by a defined search strategy and will be considered for inclusion against predefined criteria. Study selection and data extraction will be performed by 2 independent reviewers. Statistical analysis will include the identification of data sources and documentation of estimates, as well as the application of the randomeffects and fixed-effects meta-analysis models. This will allow us to aggregate prevalence estimates and account for between-study variability in calculating the overall pooled estimates and 95 CI for the prevalence of Gram-negative bacteria in VAP in NICUs. Heterogeneity will be evaluated using the I2 and ÷2 statistical tests to determine the extent of variation in effect estimates due to heterogeneity rather than chance. Publication bias and data synthesis will be assessed by funnel plots and Begg's and Egger's tests using STATA software V.13. This systematic review protocol was prepared according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses Protocols (PRISMA-P) 2015 Statement. Ethics and dissemination: No ethical issues are predicted. These findings will be published in a peerreviewed journal and presented at national and international conferences. Trial registration number: CRD42016036048. © 2016 Published by the BMJ Publishing Group Limited

    Clinico-epidemiological profile of VRE enterococcus faecium in Shariati hospital in Tehran

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    Background: Owing to restricted treatment options, Vancomycin-resistant Enterococci (VRE) was considered a prominent cause of nosocomial infections. This study was undertaken to evaluate the presence of Van-type and virulence determinants in the clinical isolates of E. faecium (Ent. faecium) in Shariati Hospital. Materials and Methods: A total of 150 Enterococcal isolates were surveyed. Antimicrobial susceptibility testing was performed by disc diffusion and E-test as well as the genotypic method. The presence of virulence factors, including hyaluronidase (hyl), gelatinase (gelE), aggregation substance (asa1), and Enterococci surface protein (ESP) were identified by Polymerase chain reaction (PCR). Results: Overall, 66.67 percent (80/120) of VRE Ent. faecium strains were confirmed by the PCR method. The maximum number of isolates was from urine specimens (p μg/ml) and carried a VanA phenotype (p < 0.05). In all the isolates, asa1, gelE, and ESP genes were identified in 14 (17/5), 26/3 (21/80), and 45 (36/80), respectively. E. Ent. faecium carried ESP at a significantly higher frequency presented in VRE strains (p < 0.001). The prevalence of hly determinants in the E. faecium was 20 (16) (P < 0.001). Conclusion: We, in our hospital, are faced with a high rate of VRE Ent. faecium isolates with a VanA-positive phenotype. With increasing resistance of the VRE strains to linezolid, we will encounter a serious challenge in treating VRE patients in future years. An interesting finding from the present study is that the spreading rates of ESP and hly among Ent. faecium isolates are higher. © 2019 Online Journal of Health and Allied Sciences

    Scalable and Interpretable One-class SVMs with Deep Learning and Random Fourier features

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    One-class support vector machine (OC-SVM) for a long time has been one of the most effective anomaly detection methods and extensively adopted in both research as well as industrial applications. The biggest issue for OC-SVM is yet the capability to operate with large and high-dimensional datasets due to optimization complexity. Those problems might be mitigated via dimensionality reduction techniques such as manifold learning or autoencoder. However, previous work often treats representation learning and anomaly prediction separately. In this paper, we propose autoencoder based one-class support vector machine (AE-1SVM) that brings OC-SVM, with the aid of random Fourier features to approximate the radial basis kernel, into deep learning context by combining it with a representation learning architecture and jointly exploit stochastic gradient descent to obtain end-to-end training. Interestingly, this also opens up the possible use of gradient-based attribution methods to explain the decision making for anomaly detection, which has ever been challenging as a result of the implicit mappings between the input space and the kernel space. To the best of our knowledge, this is the first work to study the interpretability of deep learning in anomaly detection. We evaluate our method on a wide range of unsupervised anomaly detection tasks in which our end-to-end training architecture achieves a performance significantly better than the previous work using separate training.Comment: Accepted at European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases (ECML-PKDD) 201

    The risk of nosocomial infection with multidrug-resistant corynebacterium urealyticum after prostate cancer surgery

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    Corynebacterium urealyticum is a Gram-positive, lipophilic, multidrug resistant, and urease positive microorganism with diph-theroid morphology. C. urealyticum causes several diseases such as urinary tract infection, chronic urological disease, urinary tract infections, and bacteremia in immunocompromised individuals. This study reports a rare case with nosocomial infection and hematuria caused by multidrug-resistant C. urealyticum after prostate cancer surgery. © 2019, Archives of Clinical Infectious Diseases

    High curie temperature for La5/8Sr3/8MnO3 thin films prepared by pulsed laser deposition on glass substrates

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    The manganite LSMO films were successfully grown on glass substrates without any additional buffer layer by pulsed laser deposition. The films have been investigated by X-ray diffraction (XRD), field emission-scanning electron microscope (FE-SEM), electrical and magnetic measurements. From the XRD pattern the film is found to be polycrystalline single-phase’s character. The LSMO thin films growth on glass substrate, follows the island growth model with average grain size of 44.46nm. The metal-insulator transition (TMI) temperature was above room temperature and electrical conduction mechanism of LSMO films below phase transition temperature (TP) is due to the electron-electron (major) and electron-magnon scattering processes. The Curie temperature of LSMO films is around 352 K, which is one of the high TC in all LSMO films and as our knowledge, is the highest value that is reported in literature for low cost amorphous substrates such as glass. The low resistivity, high TMI and high TC makes these LSMO films very useful for room temperature magnetic devices
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