Pancreatic cancer is one of the most common forms of malignant disease with a poor survival prognosis. Currently, nanomedicine holds great promise for targeted diagnosis and treatment of this cancer, which also reduces toxic side effects. In this work, we prepared PEG-coated monodisperse upconversion nanoparticles (UCNPs) with a conjugated Flamma® fluorescent dye for imaging and detection of particle distribution .
View Article and Find Full Text PDFThis paper introduces a formulation of the particle-in-cell (PIC) method for the modeling of relativistic plasmas, that leverages the ability of the pseudospectral analytical time-domain solver (PSATD) to handle arbitrary time dependencies of the charge and current densities during one PIC cycle (applied to second-order polynomial dependencies here). The formulation is applied to a modified set of Maxwell's equations that was proposed earlier in the context of divergence cleaning, and to recently proposed extensions of the PSATD-PIC algorithm. Detailed analysis and testings revealed that, under some condition, the formulation can expand the range of numerical parameters under which PIC simulations are stable and accurate when modeling relativistic plasmas such as, e.
View Article and Find Full Text PDFPhotodynamic therapy (PDT) has the potential to cure pancreatic cancer with minimal side effects. Visible wavelengths are primarily used to activate hydrophobic photosensitizers, but in clinical practice, these wavelengths do not sufficiently penetrate deeper localized tumor cells. In this work, NaYF:Yb,Er,Fe upconversion nanoparticles (UCNPs) were coated with polymer and labeled with -tetra(hydroxyphenyl)chlorin (mTHPC; temoporfin) to enable near-infrared light (NIR)-triggered PDT of pancreatic cancer.
View Article and Find Full Text PDFIn this study, spherical or hexagonal NaYF:Yb,Er nanoparticles (UCNPs) with sizes of 25 nm (S-UCNPs) and 120 nm (L-UCNPs) were synthesized by high-temperature coprecipitation and subsequently modified with three kinds of polymers. These included poly(ethylene glycol) (PEG) and poly(N,N-dimethylacrylamide-co-2-aminoethylacrylamide) [P(DMA-AEA)] terminated with an alendronate anchoring group, and poly(methyl vinyl ether-co-maleic acid) (PMVEMA). The internalization of nanoparticles by rat mesenchymal stem cells (rMSCs) and C6 cancer cells (rat glial tumor cell line) was visualized by electron microscopy and the cytotoxicity of the UCNPs and their leaches was measured by the real-time proliferation assay.
View Article and Find Full Text PDFUpconverting nanoparticles are interesting materials that have the potential for use in many applications ranging from solar energy harvesting to biosensing, light-triggered drug delivery, and photodynamic therapy (PDT). One of the main requirements for the particles is their surface modification, in our case using poly(methyl vinyl ether--maleic acid) (PMVEMA) and temoporfin (THPC) photosensitizer to ensure the colloidal and chemical stability of the particles in aqueous media and the formation of singlet oxygen after NIR irradiation, respectively. Codoping of Fe, Yb, and Er ions in the NaYF host induced upconversion emission of particles in the red region, which is dominant for achieving direct excitation of THPC.
View Article and Find Full Text PDFObjective: The aim is to analyze the current problems in communicative development of children with special educational needs.
Patients And Methods: Materials and methods: The research used a number of scientific methods: general scientific (analysis, synthesis, generalization), historical, specific research, comparative-historical, and others, which ensured the selection and analysis of the source base, made it possible to determine the general trends in the study of the problem of the communicative development of the child, the achievements of Ukrainian and foreign scientists in the field of research on the language of children with special educational needs, to distinguish the common and the different in the scientific research of scientists.
Conclusion: Conclusions: Updated studies of scientists from Ukraine, Poland, Sweden, Britain and other countries testify that communication skills are key in the language development of a preschool child, they form the basis without which the child's further education, socialization, etc.
Large (120 nm) hexagonal NaYF:Yb, Er nanoparticles (UCNPs) were synthesized by high-temperature coprecipitation method and coated with poly(ethylene glycol)-alendronate (PEG-Ale), poly (,-dimethylacrylamide--2-aminoethylacrylamide)-alendronate (PDMA-Ale) or poly(methyl vinyl ether--maleic acid) (PMVEMA). The colloidal stability of polymer-coated UCNPs in water, PBS and DMEM medium was investigated by dynamic light scattering; UCNP@PMVEMA particles showed the best stability in PBS. Dissolution of the particles in water, PBS, DMEM and artificial lysosomal fluid (ALF) determined by potentiometric measurements showed that all particles were relatively chemically stable in DMEM.
View Article and Find Full Text PDFProcesses of self-organization play a key role in the development of innovative functional nanocomposites, allowing, in particular, the transformation of metastable solid solutions into multilayers by activating spinodal decomposition instead of layer-by-layer film growth. We report the formation of strained layered (V,Ti)O nanocomposites in thin polycrystalline films using a spinodal decomposition. Already during the growth of VTiO films, spinodal decomposition was detected while producing atomic-scale disordered V- and Ti-rich phases.
View Article and Find Full Text PDFUpconverting nanoparticles (UCNPs) are of particular interest in nanomedicine for in vivo deep-tissue optical cancer bioimaging due to their efficient cellular uptake dependent on polymer coating. In this study, particles, 25 nm in diameter, were prepared by a high-temperature coprecipitation of lanthanide chlorides. To ensure optimal dispersion of UCNPs in aqueous milieu, they were coated with three different polymers containing reactive groups, i.
View Article and Find Full Text PDFPhytoextraction has been proposed in many papers as a low-cost method for remediating contaminated soil. However, if national regulation is based on total metal(loid) concentrations in soil, phytoextraction is generally infeasible because of the long time required for remediation. Assessing phytoextraction requires determination of the dynamic rate of metal removal from soil.
View Article and Find Full Text PDFNovel Yb,Tb,Nd-doped GdF and NaGdF nanoparticles were synthesized by a coprecipitation method in ethylene glycol (EG) in the presence of the poly(4-styrenesulfonic acid--maleic anhydride) stabilizer. The particle size and morphology, crystal structure, and phase change were controlled by adjusting the PSSMA concentration and source of fluoride anions in the reaction. Doping of Yb, Tb, and Nd ions in the NaGdF host nanoparticles induced luminescence under ultraviolet and near-infrared excitation and high relaxivity in magnetic resonance (MR) imaging (MRI).
View Article and Find Full Text PDFMetal contamination of soil has become a serious environmental problem worldwide. Many studies have attempted to infer metal ecotoxicity from soil microbial responses. However, much of the data from these studies tends to be inconsistent and difficult to interpret.
View Article and Find Full Text PDFSurface engineering of upconverting nanoparticles (UCNPs) is crucial for their bioanalytical applications. Here, an antibody specific to cardiac troponin I (cTnI), an important biomarker for acute myocardial infection, was covalently immobilized on the surface of UCNPs to prepare a label for the detection of cTnI biomarker in an upconversion-linked immunoassay (ULISA). Core-shell UCNPs (NaYF:Yb,Tm@NaYF) were first coated with poly(methyl vinyl ether-alt-maleic acid) (PMVEMA) and then conjugated to antibodies.
View Article and Find Full Text PDFExplicit electromagnetic particle-in-cell (PIC) codes are typically limited by the Courant-Friedrichs-Lewy (CFL) condition, which implies that the timestep multiplied by the speed of light must be smaller than the smallest cell size. In the case of boosted-frame PIC simulations of plasma-based acceleration, this limitation can be a major hindrance, as the cells are often very elongated along the longitudinal direction and the timestep is thus limited by the small, transverse cell size. This entails many small-timestep PIC iterations and can limit the potential speed-up of the boosted-frame technique.
View Article and Find Full Text PDFMultimodal gadolinium fluoride nanoparticles belong to potential contrast agents useful for bimodal optical fluorescence and magnetic resonance imaging. However, the metallic nature of the nanoparticles, similarly to some paramagnetic iron oxides, might induce allergic and anaphylactic reactions in patients after administration. A reduction of these adverse side effects is a priority for the safe application of the nanoparticles.
View Article and Find Full Text PDFUpconverting luminescent lanthanide-doped nanoparticles (UCNP) belong to promising new materials that absorb infrared light able to penetrate in the deep tissue level, while emitting photons in the visible or ultraviolet region, which makes them favorable for bioimaging and cell labeling. Here, we have prepared upconverting NaYF:Yb,Er@NaYF:Nd core-shell nanoparticles, which were coated with copolymers of N,N-dimethylacrylamide (DMA) and 2-(acryloylamino)-2-methylpropane-1-sulfonic acid (AMPS) or tert-butyl [2-(acryloylamino)ethyl]carbamate (AEC-Boc) with negative or positive charges, respectively. The copolymers were synthesized by a reversible addition-fragmentation chain transfer (RAFT) polymerization, reaching M ~ 11 kDa and containing ~ 5 mol% of reactive groups.
View Article and Find Full Text PDFHere we evaluate an alternative protocol to histologically examine blood-brain barrier (BBB) breakdown, brain edema, and lesion volume following traumatic brain injury (TBI) in the same set of rodent brain samples. We further compare this novel histological technique to measurements determined by magnetic resonance imaging (MRI) and a neurological severity score (NSS). Sixty-six rats were randomly assigned to a sham-operated, mild TBI, moderate TBI, or severe TBI group.
View Article and Find Full Text PDFMultimodal imaging, integrating several modalities including down- and up-conversion luminescence, - and ( *)-weighted MRI, and CT contrasting in one system, is very promising for improved diagnosis of severe medical disorders. To reach the goal, it is necessary to develop suitable nanoparticles that are highly colloidally stable in biologically relevant media. Here, hydrophilic poly(,-dimethylacrylamide--acryloylglycine methyl ester)-alendronate-[P(DMA-AGME)-Ale]-coated Gd(Tb)F:Tb(Gd),Yb,Nd nanoparticles were synthesized by a coprecipitation method in ethylene glycol (EG) followed by coating with the polymer.
View Article and Find Full Text PDFObjective: The aim: To evaluate the efficacy of endoscopic variceal band ligation (EVL) after the first esophageal EVL session in children with PH according to endoscopic data.
Patients And Methods: Materials and methods: EVL was performed to 39 patients with PH for the purpose of variceal bleeding primary and secondary prophylaxis.
Results: Results: Esophageal varices grade decrease was observed in 22 (56.
Discretizing Maxwell's equations in Galilean (comoving) coordinates allows the derivation of a pseudospectral solver that eliminates the numerical Cherenkov instability for electromagnetic particle-in-cell simulations of relativistic plasmas flowing at a uniform velocity. Here we generalize this solver by incorporating spatial derivatives of arbitrary order, thereby enabling efficient parallelization by domain decomposition. This allows scaling of the algorithm to many distributed compute units.
View Article and Find Full Text PDFThe use of silver nanoparticles (NPs) in medical, industrial and agricultural fields is becoming more widespread every year. This leads to an increasing number of experimental toxicological and microbiological studies of silver NPs aimed at establishing the risk-benefit ratio for their application. The following key parameters affecting the biological activity of silver dispersions are traditionally taken into consideration: mean diameter of NPs, surface potential of NPs and equilibrium concentration of Ag.
View Article and Find Full Text PDFBiocompatible poly(4-styrenesulfonic acid-co-maleic acid)-stabilized GdF : Eu (Tb ) nanoparticles were obtained by a one-step coprecipitation method in ethylene glycol or water. The particles are very small (3 nm), have a narrow size distribution, and were detectable by fluorescence, magnetic resonance, and X-ray contrast imaging. These properties allow multimodal imaging, which has prospective applications in the simultaneous and detailed detection of diseased tissues.
View Article and Find Full Text PDFA long-standing issue in the physics of the colossal magnetoresistance is the role of electron-phonon coupling, which manifests itself as Jahn-Teller polarons. The origin and architecture of polarons makes it possible to study their behavior by Raman spectroscopy, which allows to analyze the polaronic behavior in an applied magnetic field. We performed magnetic-field-dependent Raman spectroscopy on thin films of (LaPr)CaMnO in a range of H = 0-50 kOe and compared the obtained Raman spectra with the magnetic field behavior of the electrical resistivity.
View Article and Find Full Text PDFThe purpose of the study is to establish the effect of the investigated drug PDT-Na on the parameters of free radical lipid oxidation and the system of antioxidant defence of the kidneys in rats on models of acute renal failure and gentamicin nephropathy. The studies were conducted on 96 white mature, full-grown non-linear rats of both sexes weighing 150-170 grams. The animals were divided into 16 groups (5 groups per model and one intact group): the animals of the experimental, reference and control pathology groups (1) received the corresponding nephrotoxin.
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