407 research outputs found
The fabrication of potentiometric membrane sensors and their applications
Ionophore-incorporated PVC-membrane sensors are well-established analytical tools routinely used for the selective and direct measurement of a wide variety of different ions in complex biological and environmental samples. The key ingredient of such plasticized PVC-members is the involved ionophore, defining the selectivity of the electrodes complex formation with the cation of interest. In the past few years, the development of new ion-selective electrodes for various ions has been reported inthe literature
Safety, effectiveness and economic evaluation of intra-operative radiation therapy: A systematic review
Background: Intra-operative radiation therapy (IORT) is the transfer of a single large radiation dose to the tumor bed during surgery with the final goal of improving regional tumor control. This study aimed to investigate the safety, effectiveness and economic evaluation of intra-operative radiation therapy. Methods: The scientific literature was searched in the main biomedical databases (Centre for Reviews and Dissemination, Cochrane Library and PubMed) up to March 2014. Two independent reviewers selected the papers based on pre-established inclusion criteria, with any disagreements being resolved by consensus. Data were then extracted and summarized in a structured form. Results from studies were analyzed and discussed within a descriptive synthesis. Results: Sixteen studies met the inclusion criteria. It seems that outcomes from using intraoperative radiation therapy can be considered in various kinds of cancers like breast, pancreatic and colorectal cancers. The application of this method may provide significant survival increase only for colorectal cancer, but this increase was not significant for other types of cancer. This technology had low complications; and it is relatively safe. Using intra-operative radiation therapy could potentially be accounted as a cost-effective strategy for controlling and managing breast cancer. Conclusion: According to the existing evidences, that are the highest medical evidences for using intra-operative radiation therapy, one can generally conclude that intra-operative radiation therapy is considered as a relatively safe and cost-effective method for managing early-stage breast cancer and it can significantly increase the survival of patients with colorectal cancer. Also, the results of this study have policy implications with respect to the reimbursement of this technology
Effect of Bending Anisotropy on the 3D Conformation of Short DNA Loops
The equilibrium three dimensional shape of relatively short loops of DNA is
studied using an elastic model that takes into account anisotropy in bending
rigidities. Using a reasonable estimate for the anisotropy, it is found that
cyclized DNA with lengths that are not integer multiples of the pitch take on
nontrivial shapes that involve bending out of planes and formation of kinks.
The effect of sequence inhomogeneity on the shape of DNA is addressed, and
shown to enhance the geometrical features. These findings could shed some light
on the role of DNA conformation in protein--DNA interactions
Deletion Robust Submodular Maximization over Matroids
Maximizing a monotone submodular function is a fundamental task in machine learning. In this paper we study the deletion robust version of the problem under the classic matroids constraint. Here the goal is to extract a small size summary of the dataset that contains a high value independent set even after an adversary deleted some elements. We present constant-factor approximation algorithms, whose space complexity depends on the rank k of the matroid and the number d of deleted elements. In the centralized setting we present a (3.582 + O(ε))-approximation algorithm with summary size O(k + εd2 log kε ). In the streaming setting we provide a (5.582 + O(ε))approximation algorithm with summary size and memory O(k + εd2 log kε ). We complement our theoretical results with an in-depth experimental analysis showing the effectiveness of our algorithms on real-world datasets
Circular economy in the building and construction sector: A scientific evolution analysis
The building industry is responsible for considerable environmental impacts due to its consumption of resources and energy, and the production of wastes. Circular Economy (CE), a new paradigm can significantly improve the sustainability of this sector. This paper performs a quantitative scientific evolution analysis of the application of CE in the building sector to detect new trends and highlight the evolvement of this research topic. Around 7000 documents published 2005 to 2020 at Web of Science and Scopus were collected and analyzed. The bibliometric indicators, network citation, and multivariate statistical analysis were obtained using Bibliometrix R-package and VOSviewer. The co-occurrence analysis showed five keyword-clusters, in which the three main ones are: (i) energy and energy efficiency in buildings; (ii) recycling, waste management and alternative construction materials; (iii) sustainable development. The analysis showed that researchers pay close attention to 'sustainability', 'energy efficiency', 'life cycle assessment', 'renewable energy', and 'recycling' in the past five years. This paper highlights that (i) the development and use of alternative construction materials; (ii) the development of circular business models; (iii) smart cities, Industry 4.0 and their relations with CE, are the current research hotspots that may be considered as potential future research topics.The authors would like to acknowledge financial support from the Spanish Ministry of Economy and Competitiveness RTI2018-093849-B-C33 (MCIU/AEI/FEDER, UE), RTI2018-093849-B-C31 (MCIU/AEI/FEDER, UE) and CTQ2016-77968-C3-1-P (MINECO/FEDER) and thank the Catalan Government (2017-SGR-1409, 2017-SGR-1537, and 2019 FI-B-00762). This work was partially funded by the Ministerio de Ciencia, Innovación y Universidades - Agencia Estatal de Investigación (AEI) (RED2018-102431-T). GREiA is a certified agent TECNIO in the category of technology developers from the Government of Catalonia. This work is partially supported by ICREA under the ICREA Academia programme
Genetic variability and differentiation of common Kilka fish (Clupeonella cultriventris Nordmann, 1840) in the southern coasts of Caspian Sea
A total of 120 samples of adult common Kilka fish (Clupeonella cultriventris) were collected during spring and summer from the southern coasts of Caspian Sea (Bandar Anzali and Babolsar). Fifteen sets of microsatellite primers were developed from Clupeidae being tested on genomic DNA of common Kilka. Allele frequency, observed and expected heterozygosity, FST, RST, FIS index were determined. Five primer sets as polymorphic loci were used to analyze the genetic variation in adults of the common Kilka population. Results revealed that average alleles per locus was 13.1 (range 5 to 22 alleles per locus in regions, Ne=9.5). All sampled regions contained private alleles. Average observed and expected heterozygosity was 0.348 and 0.877, respectively. Deviations from Hardy Weinberg equilibrium were observed in most cases. FST, RST and gene flow estimates in AMOVA and the genetic distance between populations indicated that the genetic difference among the studied populations was pronounced. The data generated in this study provide primary information on the genetic variation and differentiation in populations of Caspian common Kilka
Comparing Probabilistic Models for Melodic Sequences
Modelling the real world complexity of music is a challenge for machine
learning. We address the task of modeling melodic sequences from the same music
genre. We perform a comparative analysis of two probabilistic models; a
Dirichlet Variable Length Markov Model (Dirichlet-VMM) and a Time Convolutional
Restricted Boltzmann Machine (TC-RBM). We show that the TC-RBM learns
descriptive music features, such as underlying chords and typical melody
transitions and dynamics. We assess the models for future prediction and
compare their performance to a VMM, which is the current state of the art in
melody generation. We show that both models perform significantly better than
the VMM, with the Dirichlet-VMM marginally outperforming the TC-RBM. Finally,
we evaluate the short order statistics of the models, using the
Kullback-Leibler divergence between test sequences and model samples, and show
that our proposed methods match the statistics of the music genre significantly
better than the VMM.Comment: in Proceedings of the ECML-PKDD 2011. Lecture Notes in Computer
Science, vol. 6913, pp. 289-304. Springer (2011
PVA-Based Nanofibers Containing Chitosan Modified with Graphene Oxide and Carbon Quantum Dot-Doped TiO2 Enhance Wound Healing in a Rat Model
Electrospun nanofibrous constructs based on nanoparticles and biopolymers have recently been used in tissue engineering because of their similarity to the extracellular matrix in nature. In this study, electrospun chitosan-carbon quantum dot-titanium dioxide-graphene oxide (CS-CQD-TiO2-GO) nanofibrous mats were synthesized for use as wound dressings by the electrospinning method. To increase the biodegradation rate and water resistance, the fabricated nanofibrous mats were cross-linked. SEM images showed a uniform and coherent structure of CS-CQD-TiO2-GO nanocomposites and CS-CQD-TiO2-GO electrospun nanofibers mats. FTIR analysis, XRD pattern, SEM mapping, and EDS spectrum demonstrate the accuracy of the synthesis as well as the elemental and chemical structure of the nanofibrous mat. The water contact angle indicated that the nanofibrous mat had a hydrophilic property, which is essential for controlling wound exudates. The tensile strength and elongation tests showed that the nanofibrous mat has suitable mechanical properties for wound dressing, including significant flexibility and strength. Interestingly, antimicrobial testing illustrated that the fabricated nanofibrous mat had antibacterial activity against Gram-negative and Gram-positive bacteria. Appropriate cell viability and cytocompatibility of treated mouse fibroblast NIH3T3 cells with the nanofibrous mat were determined using an MTT assay. The animal study results confirmed the proper potential of the nanofibrous mat in wound dressing applications
Emerging Carbapenem-Resistant Pseudomonas aeruginosa Isolates Carrying bla<sub>IMP</sub> Among Burn Patients in Isfahan, Iran
Background: Metallo-β-lactamase (MBL)-producing Pseudomonas aeruginosa is a significant pathogen in burn patients.
Objectives: The aim of this study was to determine the prevalence of carbapenem-resistant P. aeruginosa isolates, including those resistant to imipenemase (IMP), in a burn unit in Isfahan, Iran.
Patients and Methods: One hundred and fifty P. aeruginosa isolates from burn patients were tested for antibiotic susceptibility by the disc diffusion method in accordance with CLSI guidelines. Production of MBL was identified with the EDTA disk method. DNA was purified from the MBL-positive isolates, and detection of the blaIMP gene was performed with PCR.
Results: Fifty-seven out of 150 (38%) isolates were multi-drug resistant (MDR), and 93 (62%) were extensively-drug resistant (XDR). Among all isolates, the resistance rate to ciprofloxacin, tobramycin, imipenem, meropenem, amikacin, ceftazidime, and cefepime was higher than 90%, while the resistance rates to piperacillin/tazobactam and aztreonam were 70.7% and 86%, respectively. Colistin and polymyxin B remained the most effective studied antibiotics. All of the imipenem-resistant P. aeruginosa isolates were MBL-positive, and 107 out of 144 (74.3%) of the MBL isolates were positive for the blaIMP gene.
Conclusions: The results of this study show that the rate of P. aeruginosa-caused burn wound infections was very high, and many of the isolates were resistant to three or more classes of antimicrobials. Such extensive resistance to antimicrobial classes is important because few treatment options remain for patients with burn wound infections. blaIMP-producing P. aeruginosa isolates are a rising threat in burn-care units, and should be controlled by conducting infection-control assessments
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