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11.
Érica Aparecida de Oliveira Bluma Linkowski Faintuch Daniele Seo Angélica Bueno Barbezan Ana Funari Roselaine Campos Targino Ana Maria Moro 《Applied biochemistry and biotechnology》2018,185(4):863-874
Early and accurate detection of primary or metastatic tumors is of great value in staging, treatment management, and prognosis. Tumor angiogenesis plays an essential role in the growth, invasion, and metastatic spread of solid cancers, and so, is a promising approach for tumor imaging. The GX1 (CGNSNPKSC) peptide was identified by phage display library and has been investigated as a marker for human cancers. This study aims to evaluate the 99mTc-HYNIC-PEG4-c (GX1) as a biomarker for tumor imaging. Our results showed that GX1 specifically binds to tumor cells in vitro. SKMEL28 and MDA-MB231 cells achieved total binding peak at 60 min of incubation. For B16F10 and MKN45 cells, the total and specific binding were similar during all time points, while A549 cell line showed rapid cellular total uptake of the tracer at 30 min of incubation. Biodistribution showed low non-specific uptakes and rapid renal excretion. Melanoma tumors showed enhanced GX1 uptake in animal model at 60 min, and it was significantly blocked by cold peptide. The radiotracer showed tumor specificity, especially in melanomas that are highly vascularized tumors. In this sense, it should be considered in future studies, aiming to evaluate degree of angiogenesis, progression, and invasion of tumors. 相似文献
12.
Miasnikova A Laschewsky A De Paoli G Papadakis CM Müller-Buschbaum P Funari SS 《Langmuir : the ACS journal of surfaces and colloids》2012,28(9):4479-4490
A series of symmetrical, thermo-responsive triblock copolymers was prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization, and studied in aqueous solution with respect to their ability to form hydrogels. Triblock copolymers were composed of two identical, permanently hydrophobic outer blocks, made of low molar mass polystyrene, and of a hydrophilic inner block of variable length, consisting of poly(methoxy diethylene glycol acrylate) PMDEGA. The polymers exhibited a LCST-type phase transition in the range of 20-40 °C, which markedly depended on molar mass and concentration. Accordingly, the triblock copolymers behaved as amphiphiles at low temperatures, but became water-insoluble at high temperatures. The temperature dependent self-assembly of the amphiphilic block copolymers in aqueous solution was studied by turbidimetry and rheology at concentrations up to 30 wt %, to elucidate the impact of the inner thermoresponsive block on the gel properties. Additionally, small-angle X-ray scattering (SAXS) was performed to access the structural changes in the gel with temperature. For all polymers a gel phase was obtained at low temperatures, which underwent a gel-sol transition at intermediate temperatures, well below the cloud point where phase separation occurred. With increasing length of the PMDEGA inner block, the gel-sol transition shifts to markedly lower concentrations, as well as to higher transition temperatures. For the longest PMDEGA block studied (DP(n) about 450), gels had already formed at 3.5 wt % at low temperatures. The gel-sol transition of the hydrogels and the LCST-type phase transition of the hydrophilic inner block were found to be independent of each other. 相似文献
13.
A. Di Muccio M. Chirico R. Dommarco E. Funari L. Musmeci A. Santilio 《International journal of environmental analytical chemistry》2013,93(2):211-220
Abstract Atrazine is considered a potential contaminant of water bodies, where it has been repeatedly detected. Its use in Italy is almost limited to the Northern part of the country where corn monocultures are common. Northern Italy is characterized by the presence of an area with soil quite permeable and where ground waters are often present at not very deep levels. In this area well waters, which represent the main source of drinking water, have been frequently found contaminated by atrazine. A program has been started aimed at studying the role of soil nature and local factors in the process of groundwater contamination. Two atrazine application rates were used at two sites with loamy and loamy-sandy soils. Results clearly show a different mobility of atrazine in the two soil types. Since the two sites have similar organic carbon levels, the major proportion of clay to sand and the lower pH of loamy soil may explain the lower vertical mobility of atrazine in this soil. Work is in progress to study atrazine behaviour to a soil depth of 30cm and the effect of repeated atrazine applications on ground water pollution. 相似文献
14.
WANG Er-Kang ZHOU Wei-HongLaboratory of Electroanalytical Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun Jilin SS China 《中国化学》1996,14(2):131-137
Capillary electrpphoresis (CE)/electrochemical detection (EC) for the simultane-ous determination of hydrazine and isoniazid has been developed.The electrochemical method uses a novel modified electrode dispersed with ultrafine platinum particles on the surface of a 30μm carbon fiber microelectrode.The unique characteristic of the Pt-particles modified carbon fiber microelectrode is its excellent stability.The current measurement for hydrazine is more sensitive than that of isoniazid.Selective determination of trace amount of free hydrazine in isoniazid and its formulation can be achieved at applied potential of 0.5V. 相似文献
15.
Alvarez C Nogales A García-Gutiérrez MC Sanz A Denchev Z Funari SS Bruix M Ezquerra TA 《The European physical journal. E, Soft matter》2005,18(4):459-465
The isothermal cold crystallization of poly(ethylene terephthalate)(PET) in
cryogenic mechanical alloyed blends of PET and Poly(ethylene naphthalene
2,6-dicarboxilate)(PEN) 1:1 by weight has been investigated by simultaneous
small and wide angle X-ray scattering (SAXS and WAXS) and dielectric
spectroscopy (DS). For transesterification levels higher than 23% the
blends tend to transform into a one-phase system and the crystallization of
PET is strongly inhibited due to the significant reduction of the PET
segment length. For lower levels of transesterification the blends are phase
separated and the overall crystallization behaviour can be explained
considering the confined nature of the PET domains in these blends. The
formation of a rigid amorphous phase in the intra-lamellar stack amorphous
regions is reduced in the blends due to a lower probability of stack
formation in the confined PET-rich domains. The more effective filling of
the space by the lamellar crystals in the blends provokes a stronger
restriction to the amorphous phase mobility of PET in the blends than in
pure PET. 相似文献
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17.
A poly(ether ester) thermoplastic elastomer with a soft block content of 50 wt % has been studied with synchrotron small‐angle X‐ray scattering (SAXS) during strain/relaxation cycles. The rigid nodes of the elastic network are not the hard domains themselves but instead are ordered three‐dimensional assemblies of several hard domains. At a critical elongation, single hard domains are disrupted and dislocated from these assemblies in a peculiar manner. In the ultimate structure, remaining pairs of hard domains form (semi)elastic nodes. The complex two‐dimensional SAXS patterns indicate stacks from tilted lamellae that are destroyed when the sample is strained to double its initial length. With multidimensional chord distribution function analysis, the complex nanostructure and its evolution in the draw experiment have been analyzed. The fundamental hard domains are not lamellae but cylinders (5 nm × 8 nm) arranged on a lattice at cylindrical coordinates (r12, r3), which are given by the intersections of r3(r12) = ±1.5r12 ± 13nmn, n being a natural number. A semielastic component is made from hard domains forming other lamellar assemblies, which are characterized by n = 3/2. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 1947–1954, 2003 相似文献
18.
A Soibel SS Banerjee Y Myasoedov ML Rapparort E Zeldov S Ooi T Tamegai 《Pramana》2002,58(5-6):893-898
Using a novel differential magneto-optical imaging technique we investigate the phenomenon of vortex lattice melting in crystals
of Bi2Sr2CaCu2O8 (BSCCO). The images of melting reveal complex patterns in the formation and evolution of the vortex solid-liquid interface
with varying field (H)/temperature (T). We believe that the complex melting patterns are due to a random distribution of material disorder/inhomogeneities across
the sample, which create fluctuations in the local melting temperature or field value. To study the fluctuations in the local
melting temperature/field, we have constructed maps of the melting landscape T
m(H, r), viz., the melting temperature (T
m) at a given location (r) in the sample at a given field (H). A study of these melting landscapes reveals an unexpected feature: the melting landscape is not fixed, but changes rather
dramatically with varying field and temperature along the melting line. It is concluded that the changes in both the scale
and shape of the landscape result from the competing contributions of different types of quenched disorder which have opposite
effects on the local melting transition. 相似文献
19.
Paineau E Bihannic I Baravian C Philippe AM Davidson P Levitz P Funari SS Rochas C Michot LJ 《Langmuir : the ACS journal of surfaces and colloids》2011,27(9):5562-5573
In this article, we present a general overview of the organization of colloidal charged clay particles in aqueous suspension by studying different natural samples with different structural charges and charge locations. Small-angle X-ray scattering experiments (SAXS) are first used to derive swelling laws that demonstrate the almost perfect exfoliation of clay sheets in suspension. Using a simple approach based on geometrical constraints, we show that these swelling laws can be fully modeled on the basis of morphological parameters only. The validity of this approach was further extended to other clay data from the literature, in particular, synthetic Laponite. For all of the investigated samples, experimental osmotic pressures can be properly described by a Poisson-Boltzmann approach for ionic strength up to 10(-3) M, which reveals that these systems are dominated by repulsive electrostatic interactions. However, a detailed analysis of the Poisson-Boltzmann treatment shows differences in the repulsive potential strength that are not directly linked to the structural charge of the minerals but rather to the charge location in the structure for tetrahedrally charged clays (beidellite and nontronites) undergoing stronger electrostatic repulsions than octahedrally charged samples (montmorillonites, laponite). Only minerals subjected to the strongest electrostatic repulsions present a true isotropic to nematic phase transition in their phase diagrams. The influence of ionic repulsions on the local order of clay platelets was then analyzed through a detailed investigation of the structure factors of the various clay samples. It appears that stronger electrostatic repulsions improve the liquidlike positional local order. 相似文献
20.
Funari SS Rebbin V Marzorati L di Vitta C 《Langmuir : the ACS journal of surfaces and colloids》2011,27(13):8257-8262
We synthesize and characterize alkylthiohydroquinones (ATHs) in order to investigate their interactions with lipid model membranes, POPE and POPC. We observe the formation of structures with different morphologies, or curvature of the lipid bilayer, depending on pH and increasing temperature. We attribute their formation to changes in the balance charge/polarity induced by the ATHs. Mixtures of ATHs with POPE at pH 4 form two cubic phases, P4(3)32 and Im3m, that reach a maximum lattice size at 40 °C while under basic conditions these phases only expand upon heating from room temperature. The cubic phases coexist with lamellar or hexagonal phases and are associated with inhomogeneous distribution of the ATH molecules over the lipid matrix. The zwitterionic POPC does not form cubic phases but instead shows lamellar structures with no clear influence of the 2,6-BATH. 相似文献