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  1 / 10939 MEDLINE  
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PMID:29273907
Autor:Ghiasvand AR; Nouriasl K; Yazdankhah F
Endereço:Department of Chemistry, Lorestan University, Khoramabad, Lorestan Province, 6713817133, Iran. a_ghiasvand@yahoo.com.
Título:Comparison of the atmospheric- and reduced-pressure HS-SPME strategies for analysis of residual solvents in commercial antibiotics using a steel fiber coated with a multiwalled carbon nanotube/polyaniline nanocomposite.
Fonte:Anal Bioanal Chem; 410(2):361-371, 2018 Jan.
ISSN:1618-2650
País de publicação:Germany
Idioma:eng
Resumo:A low-cost, sensitive and reliable reduced-pressure headspace solid-phase microextraction (HS-SPME) setup was developed and evaluated for direct extraction of residual solvents in commercial antibiotics, followed by determination by gas chromatography with flame ionization detection (GC-FID). A stainless steel narrow wire was made porous and adhesive by platinization by a modified electrophoretic deposition method and coated with a polyaniline/multiwalled carbon nanotube nanocomposite. All experimental variables affecting the extraction efficiency were investigated for both atmospheric-pressure and reduced-pressure conditions. Comparison of the optimal experimental conditions and the results demonstrated that the reduced-pressure strategy leads to a remarkable increase in the extraction efficiency and reduction of the extraction time and temperature (10 min, 25 °Ï¹ vs 20 min, 40 °Ï¹). Additionally, the reduced-pressure strategy showed better analytical performances compared with those obtained by the conventional HS-SPME-GC-FID method. Limit of detections, linear dynamic ranges, and relative standard deviations of the reduced-pressure HS-SPME procedure for benzene, toluene, ethylbenzene, and xylene (BTEX) in injectable solid drugs were obtained over the ranges of 20-100 pg g , 0.02-40 µg g , and 2.8-10.2%, respectively. The procedure developed was successful for the analysis of BTEX in commercial containers of penicillin, ampicillin, ceftriaxone, and cefazolin. Graphical abstract Schematic representation of the developed RP-HS-SPME setup.
Tipo de publicação: COMPARATIVE STUDY; JOURNAL ARTICLE
Nome de substância:0 (Aniline Compounds); 0 (Anti-Bacterial Agents); 0 (Nanotubes, Carbon); 0 (Solvents); 0 (Xylenes); 0 (polyaniline); 12597-69-2 (Steel)


  2 / 10939 MEDLINE  
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PMID:29238188
Autor:Zhang J; Tang H; Liu Z; Chen B
Endereço:Department of Hematology and Oncology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing.
Título:Effects of major parameters of nanoparticles on their physical and chemical properties and recent application of nanodrug delivery system in targeted chemotherapy.
Fonte:Int J Nanomedicine; 12:8483-8493, 2017.
ISSN:1178-2013
País de publicação:New Zealand
Idioma:eng
Resumo:Chemotherapy is still one of the main cancer therapy treatments, but the curative effect of chemotherapy is relatively low, as such the development of a new cancer treatment is highly desirable. The gradual maturation of nanotechnology provides an innovative perspective not only for cancer therapy but also for many other applications. There are a diverse variety of nanoparticles available, and choosing the appropriate carriers according to the demand is the key issue. The performance of nanoparticles is affected by many parameters, mainly size, shape, surface charge, and toxicity. Using nanoparticles as the carriers to realize passive targeting and active targeting can improve the efficacy of chemotherapy drugs significantly, reduce the mortality rate of cancer patients, and improve the quality of life of patients. In recent years, there has been extensive research on nanocarriers. In this review, the effects of several major parameters of nanoparticles on their physical and chemical properties are reviewed, and then the recent progress in the application of several commonly used nanoparticles is presented.
Tipo de publicação: JOURNAL ARTICLE; REVIEW
Nome de substância:0 (Antineoplastic Agents); 0 (Dendrimers); 0 (Drug Carriers); 0 (Liposomes); 0 (Micelles); 0 (Nanotubes, Carbon)


  3 / 10939 MEDLINE  
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PMID:28987402
Autor:Wang J; Chen S; Quan X; Yu H
Endereço:Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China.
Título:Fluorine-doped carbon nanotubes as an efficient metal-free catalyst for destruction of organic pollutants in catalytic ozonation.
Fonte:Chemosphere; 190:135-143, 2018 Jan.
ISSN:1879-1298
País de publicação:England
Idioma:eng
Resumo:Metal-free carbon materials have been presented to be potential alternatives to metal-based catalysts for heterogeneous catalytic ozonation, yet the catalytic performance still needs to be enhanced. Doping carbon with non-metallic heteroatoms (e.g., N, B, and F) could alter the electronic structure and electrochemical properties of original carbon materials, has been considered to be an effective method for improving the catalytic activity of carbon materials. Herein, fluorine-doped carbon nanotubes (F-CNTs) were synthesized via a facile method and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The as-synthesized F-CNTs exhibited notably enhanced catalytic activity towards catalytic ozonation for the degradation of organic pollutants. The oxalic acid removal efficiency of optimized F-CNTs was approximately two times as much as that of pristine CNTs, and even exceeded those of four conventional metal-based catalysts (ZnO, Al O , Fe O , and MnO ). The XPS and Raman studies confirmed that the covalent CF bonds were formed at the sp C sites instead of sp C sites on CNTs, not only resulting in high positive charge density of C atoms adjacent to F atoms, but remaining the delocalized π-system with intact carbon structure of F-CNTs, which then favored the conversion of ozone molecules (O ) into reactive oxygen species (ROS) and contributed to the high oxalic acid removal efficiency. Furthermore, electron spin resonance (ESR) studies revealed that superoxide radicals (O ) and singlet oxygen ( O ) might be the dominant ROS that responsible for the degradation of oxalic acid in these catalytic systems.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Environmental Pollutants); 0 (Nanotubes, Carbon); 0 (Organic Chemicals); 284SYP0193 (Fluorine); 66H7ZZK23N (Ozone); 9E7R5L6H31 (Oxalic Acid); Q80VPU408O (Fluorides)


  4 / 10939 MEDLINE  
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PMID:28464292
Autor:Charbgoo F; Behmanesh M; Nikkhah M; Kane EG
Endereço:Department of Nanobiotechnology, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran.
Título:RNAi mediated gene silencing of ITPA using a targeted nanocarrier: Apoptosis induction in SKBR3 cancer cells.
Fonte:Clin Exp Pharmacol Physiol; 44(8):888-894, 2017 Aug.
ISSN:1440-1681
País de publicação:Australia
Idioma:eng
Resumo:A pure nucleotide pool is required for high-fidelity DNA replication and prevention of carcinogenesis in living cells. Human inosine triphosphatase (ITPase), encoded by the ITPA gene, plays a critical role in maintaining the purity of the cellular nucleotide pool by excluding nucleotides that enhance mutagenesis. ITPase is a nucleoside triphosphate pyrophosphatase that hydrolyzes the non-canonical nucleotides inosine triphosphate (ITP) and xanthine triphosphate (XTP). The monophosphate products of ITPase reactions are subsequently excluded from the nucleotide pool and the improper substitution of ITP and XTP into DNA and RNA is prevented. Previous studies show that deficiency in ITPA can suppress cellular growth and enhance DNA instability. In this study, we evaluated the influence of effective ITPA down-regulation on the induction of apoptosis in a human cancer cell line using folate-single wall nanotubes (SWNT) as a targeted nanocarrier. We assessed whether SWNT enhances IPTA-siRNA transfection efficiency in cancer cells using folate as a homing device. Since folate receptor is considerably overexpressed in cancer cells, conjugation of SWNTs to folate could enhance their cancer-specific penetrance. We found that nanocarrier mediated ITPA-siRNA transfection into SKBR3 cells caused significant reduction of ITPA mRNA expression level and complete down-regulation of the ITPase protein product. The silencing of ITPA led to promotion of apoptosis in SWNT-treated SKBR3 cancer cells.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Drug Carriers); 0 (Nanotubes, Carbon); 0 (RNA, Small Interfering); 935E97BOY8 (Folic Acid); EC 3.6.1.- (Pyrophosphatases); EC 3.6.1.19 (ITPA protein, human)


  5 / 10939 MEDLINE  
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PMID:27774728
Autor:Capriotti AL; Cavaliere C; Foglia P; La Barbera G; Samperi R; Ventura S; Laganà A
Endereço:Department of Chemistry, University of Rome "La Sapienza", Rome, Italy.
Título:Mycoestrogen determination in cow milk: Magnetic solid-phase extraction followed by liquid chromatography and tandem mass spectrometry analysis.
Fonte:J Sep Sci; 39(24):4794-4804, 2016 Dec.
ISSN:1615-9314
País de publicação:Germany
Idioma:eng
Resumo:Recently, magnetic solid-phase extraction has gained interest because it presents various operational advantages over classical solid-phase extraction. Furthermore, magnetic nanoparticles are easy to prepare, and various materials can be used in their synthesis. In the literature, there are only few studies on the determination of mycoestrogens in milk, although their carryover in milk has occurred. In this work, we wanted to develop the first (to the best of our knowledge) magnetic solid-phase extraction protocol for six mycoestrogens from milk, followed by liquid chromatography and tandem mass spectrometry analysis. Magnetic graphitized carbon black was chosen as the adsorbent, as this carbonaceous material, which is very different from the most diffuse graphene and carbon nanotubes, had already shown selectivity towards estrogenic compounds in milk. The graphitized carbon black was decorated with Fe O , which was confirmed by the characterization analyses. A milk deproteinization step was avoided, using only a suitable dilution in phosphate buffer as sample pretreatment. The overall process efficiency ranged between 52 and 102%, whereas the matrix effect considered as signal suppression was below 33% for all the analytes even at the lowest spiking level. The obtained method limits of quantification were below those of other published methods that employ classical solid-phase extraction protocols.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Estrogens); 0 (Nanotubes, Carbon)


  6 / 10939 MEDLINE  
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PMID:29376153
Autor:Das R; Rajender G; Giri PK
Endereço:Department of Physics, Indian Institute of Technology Guwahati, Guwahati - 781039, India. giri@iitg.ernet.in.
Título:Anomalous fluorescence enhancement and fluorescence quenching of graphene quantum dots by single walled carbon nanotubes.
Fonte:Phys Chem Chem Phys; 20(6):4527-4537, 2018 Feb 07.
ISSN:1463-9084
País de publicação:England
Idioma:eng
Resumo:We explore the mechanism of the fluorescence enhancement and fluorescence quenching effect of single walled carbon nanotubes (SWCNTs) on highly fluorescent graphene quantum dots (GQDs) over a wide range of concentrations of SWCNTs. At very low concentrations of SWCNTs, the fluorescence intensity of the GQDs is enhanced, while at higher concentrations, systematic quenching of fluorescence is observed. The nature of the Stern-Volmer plot for the latter case was found to be non-linear indicating a combined effect of dynamic and static quenching. The contribution of the dynamic quenching component was assessed through the fluorescence lifetime measurements. The contribution of static quenching is confirmed from the red shift of the fluorescence spectra of the GQDs after addition of SWCNTs. The fluorescence intensity is first enhanced at very low concentration due to improved dispersion and higher absorption by GQDs, while at higher concentration, the fluorescence of GQDs is quenched due to the complex formation and associated reduction of the radiative sites of the GQDs, which is confirmed from time-resolved fluorescence measurements. Laser confocal microscopy imaging provides direct evidence of the enhancement and quenching of fluorescence at low and high concentrations of SWCNTs, respectively. This study provides an important insight into tuning the fluorescence of GQDs and understanding the interaction between GQDs and different CNTs, which is important for bio-imaging and drug delivery applications.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Nanotubes, Carbon); 7782-42-5 (Graphite)


  7 / 10939 MEDLINE  
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PMID:28465075
Autor:Guven A; Villares GJ; Hilsenbeck SG; Lewis A; Landua JD; Dobrolecki LE; Wilson LJ; Lewis MT
Endereço:Department of Chemistry and the Smalley-Curly Institute, MS-60, P.O. Box 1892, Rice University, Houston, TX 77251-1892, USA.
Título:Carbon nanotube capsules enhance the in vivo efficacy of cisplatin.
Fonte:Acta Biomater; 58:466-478, 2017 Aug.
ISSN:1878-7568
País de publicação:England
Idioma:eng
Resumo:Over the past few years, numerous nanotechnology-based drug delivery systems have been developed in an effort to maximize therapeutic effectiveness of conventional drug delivery, while limiting undesirable side effects. Among these, carbon nanotubes (CNTs) are of special interest as potential drug delivery agents due to their numerous unique and advantageous physical and chemical properties. Here, we show in vivo favorable biodistribution and enhanced therapeutic efficacy of cisplatin (CDDP) encapsulated within ultra-short single-walled carbon nanotube capsules (CDDP@US-tubes) using three different human breast cancer xenograft models. In general, the CDDP@US-tubes demonstrated greater efficacy in suppressing tumor growth than free CDDP in both MCF-7 cell line xenograft and BCM-4272 patient-derived xenograft (PDX) models. The CDDP@US-tubes also demonstrated a prolonged circulation time compared to free CDDP which enhanced permeability and retention (EPR) effects resulting in significantly more CDDP accumulation in tumors, as determined by platinum (Pt) analysis via inductively-coupled plasma mass spectrometry (ICP-MS). STATEMENT OF SIGNIFICANCE: Over the past decade, drug-loaded nanocarriers have been widely fabricated and studied to enhance tumor specific delivery. Among the diverse classes of nanomaterials, carbon nanotubes (CNTs), or more specifically ultra-short single-walled carbon nanocapsules (US-tubes), have been shown to be a popular, new platform for the delivery of various medical agents for both imaging and therapeutic purposes. Here, for the first time, we have shown that US-tubes can be utilized as a drug delivery platform in vivo to deliver the chemotherapeutic drug, cisplatin (CDDP) as CDDP@US-tubes. The studies have demonstrated the ability of the US-tube platform to promote the delivery of encapsulated CDDP by increasing the accumulation of drug in breast cancer resistance cells, which reveals how CDDP@US-tubes help overcome CDDP resistance.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Antineoplastic Agents); 0 (Nanocapsules); 0 (Nanotubes, Carbon); Q20Q21Q62J (Cisplatin)


  8 / 10939 MEDLINE  
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PMID:29406107
Autor:Li X; Yuan H; Quan X; Chen S; You S
Endereço:Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Ling gong Road 2, Dalian 116024, China.
Título:Effective adsorption of sulfamethoxazole, bisphenol A and methyl orange on nanoporous carbon derived from metal-organic frameworks.
Fonte:J Environ Sci (China); 63:250-259, 2018 Jan.
ISSN:1001-0742
País de publicação:Netherlands
Idioma:eng
Resumo:Nanoporous carbons (NPCs) derived from metal-organic frameworks (MOFs) are attracting increasing attention in many areas by virtue of their high specific surface area, large pore volume and unique porosity. The present work reports the preparation of an NPC with high surface area (1731m /g) and pore volume (1.68cm /g) by direct carbonization of MOF-5. We examined the adsorption of three typical contaminants from aqueous solutions, i.e., sulfamethoxazole (SMX), bisphenol A (BPA) and methyl orange (MO), by using the as-prepared NPC. The results demonstrated that NPC could adsorb the contaminants effectively, with adsorption capacity (q ) of 625mg/g (SMX), 757mg/g (BPA) and 872mg/g (MO), respectively. These values were approximately 1.0-3.2 times higher than those obtained for single-walled carbon nanotubes (SWCNTs) and commercial powder active carbon (PAC) under the same conditions. With its high surface area and unique meso/macropore structure, the enhanced adsorption of NPC most likely originates from the cooperative interaction of a pore-filling mechanism, electrostatic interaction, and hydrogen bonding. In particular, the pH value has a crucial impact on adsorption, suggesting the significant contribution of electrostatic interaction between NPC and the contaminants. This study provides a proof-of-concept demonstration of MOF-derived nanoporous carbons as effective adsorbents of contaminants for water treatment.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Azo Compounds); 0 (Benzhydryl Compounds); 0 (Metal-Organic Frameworks); 0 (Nanotubes, Carbon); 0 (Phenols); 0 (Water Pollutants, Chemical); 16291-96-6 (Charcoal); 6B4TC34456 (methyl orange); JE42381TNV (Sulfamethoxazole); MLT3645I99 (bisphenol A)


  9 / 10939 MEDLINE  
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PMID:28992481
Autor:Wojslawski J; Bialk-Bielinska A; Paszkiewicz M; Tonski M; Stepnowski P; Dolzonek J
Endereço:Department of Environmental Analysis, Faculty of Chemistry, University of Gdansk, Wita Stwosza 63, 80-308 Gdansk, Poland.
Título:Evaluation of the sorption mechanism of ionic liquids onto multi-walled carbon nanotubes.
Fonte:Chemosphere; 190:280-286, 2018 Jan.
ISSN:1879-1298
País de publicação:England
Idioma:eng
Resumo:The knowledge of the sorption mechanism of different chemicals onto third generation carbon sorbents such as carbon nanotubes (CNTs) is needed in order to project systems for the effective removal of pollutants from the environment. This paper reports evaluation of the sorption mechanism of selected ionic liquids (ILs), being considered as potential pollutant in environment, onto various CNTs. CNTs characterized by the smallest diameter and the biggest surface area showed the highest sorption capacity to isolate ILs from an aqueous solution. CNTs with a bigger diameter, a functionalized surface and particularly a helical shape showed a lower sorption capacity. The sorption mechanism has been defined as complex, including van der Waals, π-π and electrostatic interactions with dominating π-π interactions. Due to the relatively high sorption coefficient (355.98 ± 20.69-6397.10 ± 355.42 L kg depending on the IL) the study showed that multi-walled carbon nanotubes can potentially be used to effectively isolate ILs from an aqueous solution. Moreover, proved in this study, the fast sorption kinetic, and uncomplicated regeneration process, leading to an even higher sorption capacity, means that CNTs are promising material which could find potential applications in the treatment of water contaminated by ILs.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Environmental Pollutants); 0 (Ionic Liquids); 0 (Nanotubes, Carbon); 059QF0KO0R (Water)


  10 / 10939 MEDLINE  
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PMID:28947315
Autor:Hao Y; Ma C; Zhang Z; Song Y; Cao W; Guo J; Zhou G; Rui Y; Liu L; Xing B
Endereço:Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
Título:Carbon nanomaterials alter plant physiology and soil bacterial community composition in a rice-soil-bacterial ecosystem.
Fonte:Environ Pollut; 232:123-136, 2018 Jan.
ISSN:1873-6424
País de publicação:England
Idioma:eng
Resumo:The aim of this study was to compare the toxicity effects of carbon nanomaterials (CNMs), namely fullerene (C ), reduced graphene oxide (rGO) and multi-walled carbon nanotubes (MWCNTs), on a mini-ecosystem of rice grown in a loamy potted soil. We measured plant physiological and biochemical parameters and examined bacterial community composition in the CNMs-treated plant-soil system. After 30 days of exposure, all the three CNMs negatively affected the shoot height and root length of rice, significantly decreased root cortical cells diameter and resulted in shrinkage and deformation of cells, regardless of exposure doses (50 or 500 mg/kg). Additionally, at the high exposure dose of CNM, the concentrations of four phytohormones, including auxin, indoleacetic acid, brassinosteroid and gibberellin acid 4 in rice roots significantly increased as compared to the control. At the high exposure dose of MWCNTs and C , activities of the antioxidant enzymes superoxide dismutase (SOD) and peroxidase (POD) in roots increased significantly. High-throughput sequencing showed that three typical CNMs had little effect on shifting the predominant soil bacterial species, but the presence of CNMs significantly altered the composition of the bacterial community. Our results indicate that different CNMs indeed resulted in environmental toxicity to rice and soil bacterial community in the rhizosphere and suggest that CNMs themselves and their incorporated products should be reasonably used to control their release/discharge into the environment to prevent their toxic effects on living organisms and the potential risks to food safety.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Fullerenes); 0 (Nanotubes, Carbon); 0 (Oxides); 0 (Soil); 0 (Soil Pollutants); 7782-42-5 (Graphite); EC 1.11.1.7 (Peroxidase); NP9U26B839 (fullerene C60)



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