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Artigo Revisado por pares

Arkady A. Karyakin, Elena A. Puganova, Igor A. Budashov, Ilya N. Kurochkin, Elena E. Karyakina, Vladimir Levchenko, Vladimir N. Matveyenko, S.D. Varfolomeyev,

We propose to form nanoelectrode arrays by deposition of the electrocatalyst through lyotropic liquid crystalline templates onto inert electrode support. Whereas Prussian Blue is known to be a superior electrocatalyst in hydrogen peroxide reduction, carbon materials used as electrode support demonstrate only a minor activity. We report on the possibility for nanostructuring of Prussian Blue by its electrochemical deposition through lyotropic liquid crystalline templates, which is noticed from atomic ...

Tópico(s): Analytical Chemistry and Sensors

2003 - American Chemical Society | Analytical Chemistry

Artigo Acesso aberto Revisado por pares

Konstantin K. Bobkov, Alexey V. Andrianov, M. Yu. Koptev, S. V. Muravyev, Andrei E. Levchenko, Vladimir V. Velmiskin, Svetlana S. Aleshkina, S. L. Semjonov, Denis S. Lipatov, Alexey Guryanov, A. V. Kim, Mikhail E. Likhachev,

We demonstrate a novel amplification regime in a counter-pumped, relatively long (2 meters), large mode area, highly Yb-doped and polarization-maintaining tapered fiber, which offers a high peak power directly from the amplifier. The main feature of this regime is that the amplifying signal propagates through a thin part of the tapered fiber without amplification and experiences an extremely high gain in the thick part of the tapered fiber, where most of the pump power is absorbed. In this regime, ...

Tópico(s): Optical Network Technologies

2017 - Optica Publishing Group | Optics Express

Artigo Acesso aberto Revisado por pares

Gaurav Kumar, S. Nahum Goldberg, Svetlana Gourevitch, Tatyana Levchenko, Vladimir P. Torchilin, Eithan Galun, Muneeb Ahmed,

Purpose To (a) identify key expressed genes in the periablational rim after radiofrequency ablation (RFA) and their role in driving the stimulation of distant tumor growth and (b) use adjuvant drug therapies to block key identified mediator(s) to suppress off-target tumorigenic effects of hepatic RFA. Materials and Methods This institutional animal care and use committee-approved study was performed in C57BL6 mice (n = 20) and F344 rats (n = 124). First, gene expression analysis was performed in mice after ...

Tópico(s): Cytokine Signaling Pathways and Interactions

2017 - Radiological Society of North America | Radiology

Artigo Acesso aberto Revisado por pares

Gaurav Parekh, Pravin Pattekari, Chaitanya Joshi, Tatsiana G. Shutava, Mark A. DeCoster, Tatyana Levchenko, Vladimir P. Torchilin, Yuri Lvov,

160 nm nanocapsules containing up to 60% of camptothecin in the core and 7–8 polyelectrolyte bilayers in the shell were produced by washless layer-by-layer assembly of heparin and block-copolymer of poly-l-lysine and polyethylene glycol. The outer surface of the nanocapsules was additionally modified with polyethylene glycol of 5 kDa or 20 kDa molecular weight to attain protein resistant properties, colloidal stability in serum and prolonged release of the drug from the capsules. An advantage of ...

Tópico(s): Nanoparticle-Based Drug Delivery

2014 - Elsevier BV | International Journal of Pharmaceutics

Artigo Acesso aberto Revisado por pares

Marwan Moussa, S. Nahum Goldberg, Gaurav Kumar, Rupa R. Sawant, Tatyana Levchenko, Vladimir P. Torchilin, Muneeb Ahmed,

Purpose To characterize upregulation of hypoxia-inducible factor (HIF)-1α after radiofrequency (RF) ablation and the influence of an adjuvant HIF-1α inhibitor (bortezomib) and nanodrugs on modulating RF ablation–upregulated hypoxic pathways. Materials and Methods Fisher 344 rats (n = 68) were used. First, RF ablation–induced periablational HIF-1α expression was evaluated in normal liver or subcutaneous R3230 tumors (14–16 mm). Next, the effect of varying RF ablation thermal dose (varying tip temperature ...

Tópico(s): Neuroblastoma Research and Treatments

2014 - Elsevier BV | Journal of Vascular and Interventional Radiology

Artigo Acesso aberto Revisado por pares

S Pappalardo, Cecilia Langellotti, Sebastián Di Giacomo, Valeria Olivera, Valeria Quattrocchi, Patricia Zamorano, William C. Hartner, Tatyana Levchenko, Vladimir P. Torchilin,

Dendritic cells (DC) are antigen-presenting cells uniquely capable of priming naïve T cells and cross-presenting antigens, and they determine the type of immune response elicited against an antigen. TAT peptide (TATp), is an amphipathic, arginine-rich, cationic peptide that promotes penetration and translocation of various molecules and nanoparticles into cells. TATp-liposomes (TATp-L) used for DC transfection were prepared using TATp derivatized with a lipid-terminated polymer capable of anchoring ...

Tópico(s): Immune Response and Inflammation

2014 - Dove Medical Press | International Journal of Nanomedicine

Artigo Acesso aberto Revisado por pares

Marwan Moussa, S. Nahum Goldberg, Gaurav Kumar, Rupa R. Sawant, Tatyana Levchenko, Vladimir P. Torchilin, Muneeb Ahmed,

To determine the effect of different drug-loaded nanocarriers (micelles and liposomes) on delivery and treatment efficacy for radiofrequency ablation (RFA) combined with nanodrugs.Fischer 344 rats were used (n = 196). First, single subcutaneous R3230 tumors or normal liver underwent RFA followed by immediate administration of i.v. fluorescent beads (20, 100, and 500 nm), with fluorescent intensity measured at 4-24 hr. Next, to study carrier type on drug efficiency, RFA was combined with micellar (20 nm) ...

Tópico(s): Nanoplatforms for cancer theranostics

2014 - Public Library of Science | PLoS ONE

Artigo Acesso aberto Revisado por pares

Rebecca S. Tirabassi, I. Christopher, Tatyana Levchenko, Vladimir P. Torchilin, Liisa K. Selin, Siwei Nie, Dennis L. Guberski, Kejian Yang,

An estimated 1 out of every 5 Americans is infected with herpes simplex virus type 2 (HSV-2). Efforts in developing a potent vaccine for HSV-2 have shown limited success. Here we describe a heterologous vaccination strategy for HSV-2 based on an intramuscular DNA prime followed by a liposome-encapsulated antigen boost delivered intranasally. Both portions of the vaccine express the immunogenic HSV-2 glycoprotein D. In female Balb/c mice, this heterologous immunisation regimen stimulated high titers ...

Tópico(s): Animal Virus Infections Studies

2010 - Elsevier BV | Vaccine

Artigo Acesso aberto Revisado por pares

Aristarchos Papagiannaros, Jaydev R. Upponi, William C. Hartner, Dmitriy Mongayt, Tatyana Levchenko, Vladimir P. Torchilin,

Abstract Background Optical imaging is a promising method for the detection of tumors in animals, with speed and minimal invasiveness. We have previously developed a lipid coated quantum dot system that doubles the fluorescence of PEG-grafted quantum dots at half the dose. Here, we describe a tumor-targeted near infrared imaging agent composed of cancer-specific monoclonal anti-nucleosome antibody 2C5, coupled to quantum dot (QD)-containing polymeric micelles, prepared from a polyethylene glycol/ ...

Tópico(s): Advanced Biosensing Techniques and Applications

2010 - BioMed Central | BMC Medical Imaging

Artigo Acesso aberto Revisado por pares

Yulia M. Ulybina, Ekatherina Sh. Kuligina, Natalia V. Mitiushkina, Maxim E. Rozanov, Alexandr O. Ivantsov, Daria N. Ponomariova, Alexandr V. Togo, E. Levchenko, Vladimir A. Shutkin, Sergiu Brenister, Peter Devilee, Boris Zhivotovsky, Ari Hirvonen, Evgeny N. Imyanitov,

Apoptosis plays a role in the elimination of DNA-damaged cells thus protecting the host from cancer development. Some data indicate that normal variations within the sequence of apoptotic genes may lead to suboptimal apoptotic capacity and therefore increased cancer risk. We tested 19 coding apoptotic gene SNPs in 2-stage molecular epidemiological study. For the preliminary sorting of SNP candidates, we employed a "comparison of extremes" approach, where 111 patients with highly pronounced LC susceptibility ( ...

Tópico(s): Hepatitis B Virus Studies

2009 - Elsevier BV | Cancer Letters

Artigo Acesso aberto Revisado por pares

Kejian Yang, Barbara J. Whalen, Rebecca S. Tirabassi, Liisa K. Selin, Tatyana Levchenko, Vladimir P. Torchilin, Edward Kislauskis, Dennis L. Guberski,

Abstract A variety of DNA vaccine prime and recombinant viral boost immunization strategies have been developed to enhance immune responses in humans, but inherent limitations to these strategies exist. There is still an overwhelming need to develop safe and effective approaches that raise broad humoral and T cell-mediated immune responses systemically and on mucosal surfaces. We have developed a novel mucosal immunization regimen that precludes the use of viral vectors yet induces potent T cell ...

Tópico(s): RNA Interference and Gene Delivery

2008 - American Association of Immunologists | The Journal of Immunology

Artigo Revisado por pares

Yuri I. Orlov, A. D. Efanov, П. Н. Мартынов, V. A. Gulevsky, Al’bert Konstantinovich Papovyants, Yuri D. Levchenko, Vladimir V. Ulyanov,

Abstract In the report, the influence of hydrodynamics of the loop with heavy liquid metal coolants (Pb and Pb–Bi) on the realization methods and efficiency of the coolant technology for the reactor installations of loop, improved loop and mono-block type of design has been studied. The last two types of installations, as a rule, are characterized by the following features: availability of loop sections with low hydraulic head and low coolant velocities, large squares of coolant free surfaces; absence ...

Tópico(s): Nuclear Engineering Thermal-Hydraulics

2007 - Elsevier BV | Nuclear Engineering and Design

Artigo Revisado por pares

Bhawna Gupta, Tatiana S Levchenko, Vladimir P. Torchilin,

In this study, we have investigated the potential of trans-activating transcriptional activator peptide (TATp)-modified liposomes to enhance the delivery of the model gene, plasmid encoding for the green fluorescent protein (pEGFP-N1), to human brain tumor U-87 MG cells in vitro and in an intracranial model in nude mice. The TATp-lipoplexes were characterized at lipid/DNA (+/-) charge ratios of 0.2, 5, 10, and 20 for size analysis and DNA complexation. The size distribution of DNA-loaded TATp-liposomes ...

Tópico(s): Immunotherapy and Immune Responses

2006 - Cognizant Communication Corporation | Oncology Research Featuring Preclinical and Clinical Cancer Therapeutics

Artigo Acesso aberto Revisado por pares

Rishikesh Sawant, J. P. Hurley, Stefano Salmaso, Amit Kale, Е. В. Толчева, Tatyana Levchenko, Vladimir P. Torchilin,

To develop targeted pharmaceutical carriers additionally capable of responding to certain local stimuli, such as decreased pH values in tumors or infarcts, targeted long-circulating PEGylated liposomes and PEG-phosphatidylethanolamine (PEG-PE)-based micelles have been prepared with several functions. First, they are capable of targeting a specific cell or organ by attaching the monoclonal antimyosin antibody 2G4 to their surface via pNP-PEG-PE moieties. Second, these liposomes and micelles were additionally ...

Tópico(s): Advanced biosensing and bioanalysis techniques

2006 - American Chemical Society | Bioconjugate Chemistry

Artigo

Mu Li, Adrián Chrastina, Tatyana Levchenko, Vladimir P. Torchilin,

Tópico(s): Synthesis and Characterization of Heterocyclic Compounds

2005 - American Scientific Publishers | Journal of Biomedical Nanotechnology

Artigo Revisado por pares

Junping Wang, Dmitriy Mongayt, Anatoly N. Lukyanov, Tatiana S Levchenko, Vladimir P. Torchilin,

Polymeric micelles consisting of poly(ethylene glycol)-distearoyl phosphoethanolamine conjugates (PEG-DSPE) loaded with Vitamin K3 (VK3) to 0.2 mg of drug/mg of carrier and with 1,8-diazabicyclo[5,4,0]undec-7-ene (DBU) to 0.06 mg of drug/mg of carrier were prepared. These micelles were stable for as long as 6 months during storage at 4 degrees C and did not change their size or release the incorporated drugs. Co-encapsulation of VK3 and DBU into PEG-DSPE micelles resulted in synergistic anticancer ...

Tópico(s): Nanoparticle-Based Drug Delivery

2004 - Elsevier BV | International Journal of Pharmaceutics

Artigo Revisado por pares

Wenqing Liang, Tatyana Levchenko, Vladimir P. Torchilin,

AbstractDifferent methods and conditions for ATP incorporation into PEGylated liposomes were compared in order to obtain a preparation with a maximized ATP content. Such a preparation may find the application for the in vivo treatment of ischemic tissues suffering from an insufficient ATP supply. Several different methods of liposome preparation and purification were used and HPLC was employed to determine the concentration of ATP in the liposomes. Thin lipid film hydration produced vesicles with ...

Tópico(s): Lipid Membrane Structure and Behavior

2004 - Taylor & Francis | Journal of Microencapsulation

Artigo Revisado por pares

Changhong Lin, Huan Ge, Puyou Ying, Tianle Wang, Min Huang, Ping Zhang, Tao Yang, Jianbo Wu, Vladimir Levchenko,

Phase change materials (PCMs) can absorb and release energy while keeping the temperature constant; hence, they play a crucial role in the thermal management field. Shape-stable phase change materials (SSPCMs) were synthesized by chemical crosslinking to address the liquid leakage problem of solid–liquid phase change materials (SLPCMs) during the phase change process. However, the abandoned SSPCMs cannot be reused and recycled, which seriously restricts their practical application. Herein, a polyurethane ...

Tópico(s): Adsorption and Cooling Systems

2023 - American Chemical Society | ACS Applied Polymer Materials

Artigo Revisado por pares

Changhong Lin, Puyou Ying, Min Huang, Ping Zhang, Tao Yang, Gang Liu, Tianle Wang, Jianbo Wu, Vladimir Levchenko,

Tópico(s): Flame retardant materials and properties

2021 - Springer Science+Business Media | Journal of Polymer Research

Artigo Revisado por pares

Damien Finch, Andrew Gleadow, Janet Hergt, Pauline Heaney, Helen Green, Cecilia Myers, Peter Veth, Sam Harper, Sven Ouzman, Vladimir Levchenko,

Tópico(s): Archaeology and ancient environmental studies

2021 - Nature Portfolio | Nature Human Behaviour

Artigo Revisado por pares

Changhong Lin, Huan Ge, Tianle Wang, Min Huang, Puyou Ying, Ping Zhang, Jianbo Wu, Shi‐Bin Ren, Vladimir Levchenko,

The realization of recyclable materials is an urgent problem to be solved for extending practical applications in industry. Herein, a simple method was proposed to prepared the recyclable materials thorough dynamic reversible chemistry. In this work, we design the recyclable and self-healing polyurethane based on the thermoreversible dynamic Diels-Alder reaction. In addition, the Halloysite nanotubes (HNTs) were introduced into the system to improve the thermal properties, mechanical properties of ...

Tópico(s): Clay minerals and soil interactions

2020 - Elsevier BV | Polymer

Artigo Acesso aberto Revisado por pares

Réka‐Hajnalka Fülöp, Alexandru T. Codilean, Klaus M. Wilcken, Tim J. Cohen, David Fink, Andrew Smith, Bin Yang, Vladimir Levchenko, Lukas Wacker, Samuel K. Marx, Nicola Stromsoe, Toshiyuki Fujioka, Tibor J. Dunai,

Understanding how sediment transport and storage will delay, attenuate, and even erase the erosional signal of tectonic and climatic forcings has bearing on our ability to read and interpret the geologic record effectively. Here, we estimate sediment transit times in Australia's largest river system, the Murray-Darling basin, by measuring downstream changes in cosmogenic 26Al/10Be/14C ratios in modern river sediment. Results show that the sediments have experienced multiple episodes of burial and ...

Tópico(s): earthquake and tectonic studies

2020 - American Association for the Advancement of Science | Science Advances

Artigo Revisado por pares

Cassandra Rowe, Christopher M. Wurster, Costijn Zwart, Michael Brand, Lindsay B. Hutley, Vladimir Levchenko, Michael I. Bird,

Abstract Northern Australia is a region where limited information exists on environments at the last glacial maximum (LGM). Girraween Lagoon is located on the central northern coast of Australia and is a site representative of regional tropical savanna woodlands. Girraween Lagoon remained a perennial waterbody throughout the LGM, and as a result retains a complete proxy record of last-glacial climate, vegetation and fire. This study combines independent palynological and geochemical analyses to demonstrate ...

Tópico(s): Coastal wetland ecosystem dynamics

2020 - Cambridge University Press | Quaternary Research

Artigo Acesso aberto Revisado por pares

Fei Peng, Sam Lin, Ilaria Patania, Vladimir Levchenko, Jialong Guo, Huimin Wang, Xing Gao,

The site of Shuidonggou Locality 2 offers important evidence for the Late Paleolithic sequence of north China. The site not only contains one of the earliest instances of ornamental freshwater shell and ostrich eggshell beads in the region, but also stone artifacts with features arguably resembling the Initial Upper Paleolithic (IUP) blade technology found farther north. The appearance of these innovative archaeological forms have been attributed to the arrival of hominin populations, possibly modern ...

Tópico(s): Forensic Anthropology and Bioarchaeology Studies

2020 - Public Library of Science | PLoS ONE

Artigo Acesso aberto Revisado por pares

Damien Finch, Andrew Gleadow, Janet Hergt, Vladimir Levchenko, Pauline Heaney, Peter Veth, Sam Harper, Sven Ouzman, Cecilia Myers, Helen Green,

The Kimberley region in Western Australia hosts one of the world's most substantial bodies of indigenous rock art thought to extend in a series of stylistic or iconographic phases from the present day back into the Pleistocene. As with other rock art worldwide, the older styles have proven notoriously difficult to date quantitatively, requiring new scientific approaches. Here, we present the radiocarbon ages of 24 mud wasp nests that were either over or under pigment from 21 anthropomorphic motifs ...

Tópico(s): Pacific and Southeast Asian Studies

2020 - American Association for the Advancement of Science | Science Advances

Artigo Revisado por pares

Damien Finch, Andrew Gleadow, Janet Hergt, Vladimir Levchenko, David Fink,

This paper reports on the development of radiocarbon dating of mud wasp nests to provide age estimates for rock art and other anthropogenic modifications to the surfaces of open rock shelters. Over 150 rock shelters in the remote Kimberley region of Western Australia were visited in five field seasons. Mud wasp nest samples were collected from 108 sites. Thirty newly constructed wasp nests were collected to understand their initial composition and to determine the major sources of carbon. Charcoal- ...

Tópico(s): Geology and Paleoclimatology Research

2019 - Elsevier BV | Quaternary Geochronology

Artigo Revisado por pares

Michael I. Bird, Michael Brand, Aaron F. Diefendorf, Jordahna Haig, Lindsay B. Hutley, Vladimir Levchenko, Peter Ridd, Cassandra Rowe, James Whinney, Christopher M. Wurster, Costijn Zwart,

This study reports palynological and geochemical results for modern and ancient sediments from 19 lakes on a rainfall gradient (784–1880 mm), across a range of savannas in Northern Australia. All proxies varied significantly across the range of sites examined, providing a robust envelope of values that can reliably be employed to identify a savanna signature in the sedimentary record. While the results indicate it is possible to identify a savanna, we found only three statistically significant relationships ...

Tópico(s): Fire effects on ecosystems

2018 - Elsevier BV | Quaternary Science Reviews

Artigo Revisado por pares

Melissa Fedrigo, Stephen B. Stewart, Sabine Kasel, Vladimir Levchenko, Raphaël Trouvé, Craig R. Nitschke,

ABSTRACT Tree ferns are slow-growing and long-lived components of temperate forests; however, these characteristics make determining size-age and population dynamics through mensuration approaches problematic while dendroecological approaches cannot be used. In this study, we use radiocarbon ( 14 C) dating of Cyathea australis and Dicksonia antarctica to (1) determine their age-to-size relationships, (2) reconstruct the age distribution of tree fern species, and (3) test if predicted ages align with ...

Tópico(s): Lichen and fungal ecology

2018 - Cambridge University Press | Radiocarbon