204 research outputs found

    Kernel-based Information Criterion

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    This paper introduces Kernel-based Information Criterion (KIC) for model selection in regression analysis. The novel kernel-based complexity measure in KIC efficiently computes the interdependency between parameters of the model using a variable-wise variance and yields selection of better, more robust regressors. Experimental results show superior performance on both simulated and real data sets compared to Leave-One-Out Cross-Validation (LOOCV), kernel-based Information Complexity (ICOMP), and maximum log of marginal likelihood in Gaussian Process Regression (GPR).Comment: We modified the reference 17, and the subcaptions of Figure

    Method validation of methotrexate in human plasma by LC-MS technique in patients with brain tumor.

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    Background and aims: A selective and sensitive high performance liquid chromatography-electrospray ionization mass spectrometry method has been established for determination of methotrexate in human plasma. Methods: Methotrexate was extracted from plasma with acetonitrile. The mobile phase consisted of acetonitrile-water-formic acid 74: 25: 1(v/v). Twenty µl of sample was chromatographically analyzed using a repacked ZORBAX-XDB-ODS C18 column (2.1mm×30mm, 3.5 micron). The mode of mass spectrometry was selected-ion monitoring (SIM). Results: Standard curve was linear (r= 0.998) over the concentration range of 0.1–100.0 ng/ml and showed a suitable accuracy and precision. The limit of detection (LOD) was 0.05ng/ml. Conclusion: The method is quick, easy, very steady and precise for the partition, assignment and evaluation of methotrexate in human plasma

    Controlled-release fertilizers: advances and challenges

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    Controlled- release fertilizers (CRFs) offer an excellent option to improve nutrients uptake by plants and reduce the environmental hazards due to excess release of chemicals. Polymer-coated fertilizers, compared to the other types of CRF, are by far the most intensively researched topic because of their great characteristics. Polymer-coated fertilizers, which are less sensitive to the soil and environmental factors, offer superior control over nutrients release for plants uptake. In recent years, the art has mainly focused on the design of biodegradable polymer-based coating for fertilizers considering the effective control on nutrient release. This review covers the basic information about CRFs with an emphasis on the development of polymer-coated fertilizers. Topics that are discussed herewith include materials and methods utilized for coated fertilizer, particularly polymer-coated fertilizers, manufacturing and related issues. The large market potential for fertilizer using necessitates more studies for development and commercial production of polymer-coated fertilizers

    Bayesian framework for mobility pattern discovery using mobile network events

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    Understanding human mobility patterns is of great importance for planning urban and extra-urban spaces and communication infrastructures. The omnipresence of mobile telephony in today’s society opens new avenues of discovering the patterns of human mobility by means of analyzing cellular network data. Of particular interest is analyzing passively collected Network Events (NEs) due to their scalability. However, mobility pattern analysis based on network events is challenging because of the coarse granularity of NEs. In this paper, we propose network event-based Bayesian approaches for mobility pattern recognition and reconstruction, mode of transport recognition and modeling the frequent trajectories

    Natural rubber- carbon nanotubes composites, recent advances and challenges for electrical applications

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    Over the last three decades, electrical and electronic industry is the leading industry in Malaysia in terms of export income and employment opportunities. However, to keep up with its international competition, Malaysia requires introducing novel improved products in this field. In this respects, using the natural resources available in the country is a fascinating option for developing electrical products. Natural rubber (NR), obtained from a tropical tree, has been widely considered as a base element in various electrical equipments. Despite of having excellent elasticity, original form of NR has low hardness, durability and tears resistance that limits its practical usage. Nanostructures, due their extraordinary characteristics, have indicated great improvements in NR-based composites. The results in terms of properties improvement are different depending on the types of nanofillers used. Among nanostructures, Carbon nanotubes (CNTs) have attracted a great attention in NR reinforcing. This paper presents the recent advances and state of the art for fabricating nanocomposites comprising NR and CNTs, as a sole filler or additive. The electrical properties of nanocomposite and its electrical applications are taken into account. The CNT/NR can be added to plastering materials for lightning protection of buildings, where high value of electrical conductivity is needed

    The association between TNP2 gene polymorphisms and Iranian infertile men with varicocele: A case-control study

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    Background: Numerous researches have provided great evidence that revealed the relationship between varicocele and sperm DNA damage. Objective: Because of the crucial role of nuclear transition proteins (TPs) in sperm DNA condensation and integrity, this case-control study was designed to study TNP2 gene nucleotide variations in Iranian patients with varicocele. Materials and Methods: PCR-SSCP and DNA sequencing were used to search for mutations in exons 1 & 2 of the TNP2 gene in 156 infertile patients with varicocele and 150 fertile men. Results: The results of sequencing showed three variants at positions c.301C > T (p.R101C), c.391C > T (p.R131 W), and g.IVS1-26G >C (rs8043625) of TNP2 gene. It was found that varicocele risk in men who have the CC genotype of g.IVS1-26G >C SNP is higher than those who don’t have these genotypes (according to Co-dominant model, Dominant model, Recessive model, and Over-dominant model). The haplotype-based analysis showed that (C/C/T) and (C/T/T) haplotypes were a risk factor of in patients with varicocele compared to controls (OR = 3.278, p = 0.000 and OR= 9.304, p = 0.038, respectively). Conclusion: Because of the significant difference in the genotype and allele frequencies of g.IVS1-26G >C SNP in the intronic region of TNP2 in patients with varicocele compared with controls and also because of the high conservation of this SNP position during evolution, this SNP may be involved in some important processes associated with the expression of this gene like mRNA splicing, but the exact mechanism is not clear

    Fluidized bed catalytic chemical vapor deposition synthesis of carbon nanotubes-a review

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    Carbon nanotubes (CNTs) are pure carbon in nanostructures with unique physico-chemical properties. They have brought significant breakthroughs in different fields such as materials, electronic devices, energy storage, separation, sensors, etc. If the CNTs are ever to fulfill their promise as an engineering material, commercial production will be required. Catalytic chemical vapor deposition (CCVD) technique coupled with a suitable reactor is considered as a scalable and relatively low-cost process enabling to produce high yield CNTs. Recent advances on CCVD of CNTs have shown that fluidized-bed reactors have a great potential for commercial production of this valuable material. However, the dominating process parameters which impact upon the CNT nucleation and growth need to be understood to control product morphology, optimize process productivity and scale up the process. This paper discusses a general overview of the key parameters in the CVD formation of CNT. The focus will be then shifted to the fluidized bed reactors as an alternative for commercial production of CNTs

    Effect of short carbon fiber surface treatment on composite properties

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    The effects of whiskerized carbon fibers (WCF) embedded as filler into polymer matrix were investigated. In this respect, composites consisting of pure polypropylene and also carbon fiber (CF)/polypropylene (PP) was fabricated and compared. Polypropylene matrix was reinforced with 2% concentration of WCF and prepared by a melt-mixing method. The tensile test indicated that the addition of 2% WCF enhanced the tensile strength and Young’s modulus by 38.1% and 28.2%, respectively. Besides that, the elongation was decreased for that sample. Dynamic mechanical analysis showed an increase of 39.2% in the stiffness of the WCF/PP composite and an improvement in the storage modulus. The tan δ for the sample was also smaller than unfilled PP and CF/PP composites. Furthermore, thermogravimetric analyses in an inert atmosphere showed a shift of temperature to the higher temperature with the addition of fillers

    Prodrug polymeric nanoconjugates encapsulating gold nanoparticles for enhanced X-Ray radiation therapy in breast cancer

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    This work was supported by the Deputy of Research of Zanjan University of Medical Sciences (A-12-848-30). J.C. acknowledges financial support from the European Research Council – ERC Starting Grant 848325.An optimal radiosensitizer with improved tumor retention have an important effect in tumor radiation therapy. Herein, gold nanoparticles (Au NPs) and drug containing, mPEG-conjugated CUR (mPEG-CUR), self-assembled NPs (mPEG-CUR@Au) were developed and evaluated as a drug carrier and radiosensitizer in a breast cancer mice model. As a result, cancer therapy efficacy was improved significantly by applying all-in-one NPs to achieve synchronous chemoradiotherapy, as evidenced by studies evaluating cell viability, proliferation, and ROS production. In vivo anticancer experiments showed that the mPEG-CUR@Au system improves the radiation sensitivity of 4T1 mammary carcinoma and completely abrogates breast cancer. This article is protected by copyright. All rights reserved.publishersversionpublishe

    Development of Ni- and Fe- based catalysts with different metal particle sizes for the production of carbon nanotubes and hydrogen from thermo-chemical conversion of waste plastics

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    Co-production of valuable hydrogen and carbon nanotubes (CNTs) has obtained growing interest for the management of waste plastics through thermo-chemical conversion technology. Catalyst development is one of the key factors for this process to improve hydrogen production and the quality of CNTs. In this work, Ni/SiO2 and Fe/SiO2 catalysts with different metal particle sizes were investigated in relation to their performance on the production of hydrogen and CNTs from catalytic gasification of waste polypropylene, using a two-stage fixed-bed reaction system. The influences of the type of metals and the crystal size of metal particles on product yields and the production of CNTs in terms of morphology have been studied using a range of techniques; gas chromatography (GC); X-ray diffraction (XRD); temperature programme oxidation (TPO); scanning electron microscopy (SEM); transmission electron microscopy (TEM) etc. The results show that the Fe-based catalysts, in particular with large particle size (∼80 nm), produced the highest yield of hydrogen (∼25.60 mmol H2 g−1 plastic) and the highest yield of carbons (29 wt.%), as well as the largest fraction of graphite carbons (as obtained from TPO analysis of the reacted catalyst). Both Fe- and Ni-based catalysts with larger metal particles produced higher yield of hydrogen compared with the catalysts with smaller metal particles, respectively. Furthermore, the CNTs formed using the Ni/SiO2-S catalyst (with the smallest metal particles around 8 nm) produced large amount of amorphous carbons, which are undesirable for the process of CNTs production
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