Search results

1

Nanostructuring of diamond films using self-assembled nanoparticles

100%

Babchenko O., Kromka A., Hruska K., Michalka M., Potmesil J., Vanecek M.

Open Physics

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2009

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vol. 7

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issue 2

310-314

EN

We report the use of gold, nickel and diamond nanoparticles as a masking material for realization of diamond nano-structures by applying the dry plasma etching process. Applying low power plasma (100 W) in a gas mixture of CF4/O2 for 5 minutes results in a formation of three different types of diamond nanostructures, depending on the mask type material and particle size. Using of the Ni mask results in realization of diamond nano-rods, applying of the Au mask brings cauliflower-like structures, and using the diamond powder allows the production of irregular nano-structures. The main advance of the presented etching procedure is use of a self-assembly strategy where no lithographic steps are implemented.

2

ADVANCED CELLULOSIC MATERIALS

100%

Brzoza-Malczewska K., Kucharska M., Wiśniewska-Wrona M., Guzińska K., Jóźwicka J., Bacciarelli-Ulacha A.

Progress on Chemistry and Application of Chitin and its Derivatives

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2015

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vol. 20

7-17

EN

Aim of the work was to prepare a method of producing chitosan and chitosan-alginate nanoparticles designed for the modification of textile cellulosic products in hygiene and medical application. Spectrophotometry was used in the estimation of the prepared nanoparticles; analyzed, too, was the particle size and antibacterial and antifungal activity.

3

Simulation and control of nanoparticle size distribution in a high temperature reactor

100%

Sadiku-Agboola O., Kolesnikov A., Sadiku E.

Polish Journal of Chemical Technology

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2012

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vol. 14

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issue 1

5-13

EN

This work focuses on the modeling, simulation and control of particle size distribution (PSD) during nanoparticle growth with the simultaneous chemical reaction, nucleation, condensation, coagulation and convective transport in a high temperature reactor. Firstly, a model known as population balance model was derived. This model describes the formation of particles via nucleation and growth. Mass and energy balances in the reactor were presented in order to study the effect of particle size distribution for each reaction mechanisms on the reactor dynamics, as well as the evolution of the concentrations of species and temperature of the continuous phase. The models were simulated to see whether the reduced population balance can be used to control the particle size distribution in the high temperature reactor. The simulation results from the above model demonstrated that the reduced population balance can be effectively used to control the PSD. The proposed method "which is the application of reduced population balance model" shows that there is some dependence of the average particle diameter on the wall temperature and the model can thus be used as a basis to synthesize a feedback controller where the manipulated variable is the wall temperature of the reactor and the control variable is the average particle diameter at the outlet of the reactor. The influence of disturbances on the average particle diameter was investigated and controlled to its new desired set point which is 1400nm using the proportional-integral-derivative controllers (PID controllers). The proposed model was used to control nanoparticle size distribution at the outlet of the reactor.

4

Structural and morphological properties of HA-ZnO powders prepared for biomaterials

88%

Moldovan M., Prodan D., Popescu V., Prejmerean C., Saroși C., Saplonţai M., Țălu S., Vasile E.

Open Chemistry

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2015

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vol. 13

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issue 1

EN

The purpose of this study was to investigate the structural and morphological properties of hydroxyapatite – zinc oxide (HA-ZnO) powders prepared to be used in an endodontic sealer formulation. The HA-ZnO was synthesized from hydroxyapatite (HA) in the presence of zinc oxide (ZnO) sol. The starting reagents were CaO, H3PO4 and a suspention of ZnO (25% in water). Following precipitation, the obtained sol was subjected to heat treatment at 110°C, 400°C, 850°C and 1050°C. The study focused on the influence of the thermal treatment on the cristallinity of precipitated powders. X-ray diffraction was used in order to study the structural properties of the obtained powder. Fourier Transform Infrared Spectroscopy (FT-IR) was used in order to evaluate the interactions between HA and ZnO. The morphology of the samples was studied by Scanning Electron Microscopy (SEM). Transmission Electron Microscopy and High Resolution Transmission Electron Microscopy (TEM, HRTEM) were used for the determination of particle size and fractal analysis. The fractal analysis of images using the standard box-counting method is presented and the results are discussed. It was demonstrated that the fractal dimension analysis is a useful method to quantitatively describe the complex microstructures and it can reveal the relation between fractal parameters.

5

Photocatalytic degradation of malachite green dye using doped and undoped ZnS nanoparticles

88%

Tolia J., Chakraborty M., Murthy Z.

Polish Journal of Chemical Technology

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2012

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vol. 14

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issue 2

16-21

EN

In the present study, ZnS nanoparticles were prepared using the mechanochemical method. The ZnS nanoparticles prepared were doped with different concentrations of manganese using metal acetate and manganese acetate by mechanochemical method. The as-prepared particles were characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The photocatalytic activity of the prepared nanoparticles samples, in the photocatalytic degradation of malachite green, had been investigated. The nanoparticles were photo induced, generating hole transfer for photocatalytic activity. The photodegradation of malachite green was observed at different pH (2-5) values, dye concentrations (10-100mg/L) and amount of ZnS nanoparticles (1-2.5 g/L). About 95% degradation of dye was observed on the addition of 2 g/L ZnS in 50 mg/L dye solution after 90 minutes illumination at 125 W. Degradation has been increased up to 99% using UV/nanoparticles/H2O2 (50 mL/L) combined process. The degradation efficiency was also compared using Mn doped ZnS nanoparticles (Zn1-x MnxS, where x = 0.01, 0.22 and 0.3). Maximum of 97% degradation was observed with 0.01% concentration of Mn. Kinetics study and performance of UV/ZnS, UV/ZnS/H2O2, UV/doped ZnS processes were evaluated to compare the efficiency of different processes.

6

Statistical Properties of a Polymer Chain in the Environment with Low Concentration of Nanoparticles

88%

A. Tsehay D., Luo M.-B.

Acta Physica Polonica A

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2018

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vol. 133

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issue 5

1274-1280

EN

We have investigated the statistical properties of polymer in the environment with low concentration of nanoparticles by using large-scale molecular dynamics simulations. The scaling law for the mean square radius of gyration was examined and simulation results for the polymer lengths 64≤N≤144 yielding a reasonably accurate value of the Flory exponent ν=0.58 at weak polymer-nanoparticle interaction ε_{PN}. Within the same range of N, the mean asphericity of the chain is independent of N. We found that the polymer behaves like a self-avoiding walk chain at small ε_{PN} and a compact sphere at large ε_{PN}. The results are attributed to the increase in the contact between polymer and nanoparticles with increasing ε_{PN}. Normal diffusions of polymer are always observed at whatever ε_{PN} and size and concentration of nanoparticles. Our result shows that the normal diffusion behavior of polymer is independent of polymer's state even though there is a phase transition from a desorbed polymer phase at small ε_{PN} to an adsorbed polymer phase at large ε_{PN}.

7

Characteristics of carbon nanomaterials and their application in the construction of potentiometric sensors – review

88%

Pietrzak K., Wardak C.

Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia

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2019

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vol. 74

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issue 2

EN

Carbon nanomaterials have been very popular in the scientific community in recent years, because of their unusual physical and chemical properties. Their high electrocatalytic activity, very good electrical conductivity and mechanical resistance mean that scientists are constantly looking for new technological solutions to take advantage of the opportunities offered by nanomaterials in many areas of human activity. One of such area are potentiometric sensors. There are many publications in which scientists describe methods of construction, analytical parameters and practical applications of new sensors obtained using carbon nanomaterials, and often also describe methods of synthesis of new original nanomaterials. The purpose of this work was to characterize carbon-based nanomaterials and their application in the construction of ion-selective electrodes.

8

Interaction of unmodified and partially silylated nanosilica with red blood cells

88%

Gun’ko V., Galagan N., Grytsenko I., Zarko V., Oranska O., Osaulenko V., Bogatyrev V., Turov V.

Open Chemistry

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2007

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vol. 5

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issue 4

951-969

EN

Interaction of red blood cells (RBCs) with unmodified and partially (50%) silylated fumed silica A-300 (nanosilica)was studied by microscopic, XRD and thermally stimulated depolarisation current (TSDC) methods. Nanosilica at a low concentration C A-300C A-300 = 1 wt% all RBCs transform into shadow corpuscles because of 100% haemolysis. Partial (one-half) hydrophobization of nanosilica leads to reduction of the haemolytic effect in comparison with unmodified silica at the same concentrations. A certain portion of the TSDC spectra of the buffered suspensions with RBC/A-300 is independent of the amounts of silica. However, significant portions of the low-and high-temperature TSDC bands have a lower intensity at C A-300 = 1 wt% than that for RBCs alone or RBC/A-300 at C A-300 = 0.01 wt.% because of structural changes in RBCs. Results of microscopic and XRD investigations and calculations using the TSDC-and NMR-cryoporometry suggest that the intracellular structures in RBCs (both organic and aqueous components) depend on nanosilica concentration in the suspension. [...]

9

Application of low-level laser radiation with TiO2, Ag/TiO2and S/TiO2on Streptococcus salivarius isolated from the oral cavity

88%

Panas M., Baryliyak A., Korniychuk O.

Current Issues in Pharmacy and Medical Sciences

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2014

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vol. 27

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issue 3

148-150

EN

In our research, we determine the effect of low-level laser irradiation with nanoparticles on Streptococcus salivarius. Photodynamic killing of periodontopathogenic bacteria may be an alternative to the systemic application of antibacterial drugs used in the treatment of periodontal diseases. The application of photosensitizing nanoparticles and their excitation by visible light of blue spectra enables effective killing of periodontopathogens. This data combined with the results demonstrates that TiO2, AgTiO2 and S/TiO2 can inhibit the proliferation of Streptococcus salivarius due to its high photocatalytic activity, which irreversibly damages the cell walls and membranes.

10

A Monte Carlo study on dose enhancement and photon contamination production by various nanoparticles in electron mode of a medical linac

88%

Toossi M. T. B., Ghorbani M., Sabet L. S., Akbari F., Mehrpouyan M.

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issue 3

489-496

EN

The aim of this study is the evaluation of electron dose enhancement and photon contamination production by various nanoparticles in the electron mode of a medical linac. MCNPX Monte Carlo code was used for simulation of Siemens Primus linac as well as a phantom and a tumor loaded with nanoparticles. Electron dose enhancement by Au, Ag, I and Fe2O3 nanoparticles of 7, 18 and 30 mg/ml concentrations for 8, 12 and 14 MeV electrons was calculated. The increase in photon contamination due to the presence of the nanoparticles was evaluated as well. The above effects were evaluated for 500 keV and 10 keV energy cut-offs defined for electrons and photons. For 500 keV energy cut-off, there was no significant electron dose enhancement. However, for 10 keV energy cut-off, a maximum electron dose enhancement factor of 1.08 was observed for 30 mg/ml of gold nanoparticles with 8 MeV electrons. An increase in photon contamination due to nanoparticles was also observed which existed mainly inside the tumor. A maximum photon dose increase factor of 1.07 was observed inside the tumor with Au nanoparticles. Nanoparticles can be used for the enhancement of electron dose in the electron mode of a linac. Lower energy electron beams, and nanoparticles with higher atomic number, can be of greater benefit in this field. Photons originating from nanoparticles will increase the photon dose inside the tumor, and will be an additional advantage of the use of nanoparticles in radiotherapy with electron beams.

11

Molecular recognition of glyconanoparticles by RCA and E. coli K88 - designing transports for targeted therapy

88%

Gallegos-Tabanico A., Sarabia-Sainz J., Sarabia-Sainz H., Carrillo Torres R., Guzman-Partida A., Monfort G., Silva-Campa E., Burgara-Estrella A., Angulo-Molina A., Acosta-Elias M., Pedroza-Montero M., Vazquez-Moreno L.

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2017

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vol. 64

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issue 4

671-677

EN

The targeted drug delivery has been studied as one of the main methods in medicine to ensure successful treatments of diseases. Pharmaceutical sciences are using micro or nano carriers to obtain a controlled delivery of drugs, able to selectively interact with pathogens, cells or tissues. In this work, we modified bovine serum albumin (BSA) with lactose, obtaining a neoglycan (BSA-Lac). Subsequently, we synthesized glyconanoparticles (NPBSA-Lac) with the premise that it would be recognized by microbial galactose specific lectins. NPBSA-Lac were tested for bio-recognition with adhesins of E. coli K88 and Ricinus communis agglutinin I (RCA). Glycation of BSA with lactose was analyzed by electrophoresis, infrared spectroscopy and fluorescence. Approximately 41 lactoses per BSA molecule were estimated. Nanoparticles were obtained using water in oil emulsion method and spheroid morphology with a range size of 300-500 nm was observed. Specific recognition of NPBSA-Lac by RCA and E. coli K88 was displayed by aggregation of nanoparticles analyzed by dynamic light scattering and atomic force microscopy. The results indicate that the lactosylated nanovectors could be targeted at the E. coli K88 adhesin and potentially could be used as a transporter for an antibacterial drug.

12

Silver nanoparticles – possible applications and threats

88%

Kędzierska M., Miłowska K.

Acta Universitatis Lodziensis. Folia Biologica et Oecologica

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2021

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vol. 17

14-31

EN

Silver is known for its biocidal properties. This metal has been used for decorations and food preservation since ancient times and has also been used in medicine. Silver foil has been used to cover wounds and burns. In addition, silver solutions were created to help fight the microorganisms responsible for causing infections, which helped the wound healing process. Currently, to increase and optimize the properties of silver, it is used on a nanometric scale. Nanosilver, due to its expanded spectrum of properties, is used in many economic sectors, including in the production of disinfectants and food films, as well as in animal farms. Nanoparticles are also the basis of nanomedicine action. Creating new drug complexes with nanosilver and modifying the medical materials used in implantology or dentistry allow the lives of many people to be saved every day. In addition, nanosilver particles are commonly used as a specific disinfectant in the production of hospital materials: dressings, bandages, surgical masks, hospital clothing and shoes, and equipment. With the growing use of nanosilver, there are concerns about its harmful effects on living organisms, because not all its mechanisms of action are known. As is well known, the dose determines the toxicity of a given substance; the case is similar for nanosilver. However, is the dose providing antibacterial and antifungal properties non-toxic to animals and humans? This review presents a summary of the scientific research showing the scope of nanosilver activity and the resulting threats.

13

Silver nanoparticle accumulation by aquatic organisms – neutron activation as a tool for the environmental fate of nanoparticles tracing

88%

Asztemborska M., Jakubiak M., Książyk M., Stęborowski R., Polkowska-Motrenko H., Bystrzejewska-Piotrowska G.

Nukleonika

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2014

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vol. 59

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issue 4

169-173

EN

Water environments are noted as being some of the most exposed to the influence of toxic nanoparticles (NPs). Therefore, there is a growing need for the investigation of the accumulation and toxicity of NPs to aquatic organisms. In our studies neutron activation followed by gamma spectrometry and liquid scintillation counting were used for studying the accumulation of silver nanoparticles (AgNPs) by freshwater larvae of Chironomus and fish Danio rerio. The influence of exposition time, concentration and the source of nanoparticles on the efficiency of AgNP accumulation were studied. It was found that AgNPs are efficiently accumulated by Chironomid larvae for the first 30 hours of exposition; then, the amount of silver nanoparticles decreases. The silver content in larvae increases together with the NP concentration in water. Larvae which have accumulated AgNPs can be a source of nanoparticles for fish and certainly higher levels of Ag in the trophic chain. In comparison with water contamination, silver nanoparticles are more efficiently accumulated if fish are fed with AgNP-contaminated food. Finally, it was concluded that the applied study strategy, including neutron activation of nanoparticles, is very useful technique for tracing the uptake and accumulation of NPs in organisms

14

Cytotoxicity of thermo-responsive polymeric nanoparticles based on N-isopropylacrylamide for potential application as a bioscaffold

75%

Deptuła T., Warowicka A., Woźniak A., Grzeszkowiak M., Jarzębski M., Bednarowicz M., Patkowski A., Słomski R.

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2015

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vol. 62

|

issue 2

311-316

EN

Polymeric nanoparticles based on poly-N-isopropylacrylamide (pNiPAM NPs) and their bio-medical applications have been widely investigated in recent years. These tunable nanoparticles are considered to be great candidates for drug delivery systems, biosensors and bioanalytical devices. Thus, the biocompatibility and toxicity of these nanoparticles is clearly a crucial issue. In this work, the cytotoxicity of thermo-responsive pNiPAM nanoparticles was studied, followed by a detailed analysis of the NPs morphology in growing cell cultures and their 3D structure. Cytotoxic examination was conducted for two cell cultures - HeLa (cervical cancer cell line) and HeK293 (human embryonic kidney cell line), employing MTT (3-4, 5-dimethylthiazol-2-yl-2, 5-diphenyltetrazolium bromide) assay and viability tests. We used Cryo-SEM (scanning electron microscopy) and fluorescence microscopy (IN Cell Analyzer) in order to investigate the morphological structure of the polymer network. We show that pNiPAM nanoparticles do not exhibit any cytotoxicity effects on the investigated cell lines. Additionally, we report that the pNiPAM nanoparticle based scaffold promotes cell growth.

15

Effect of Mn doping on the structural and optical properties of sol-gel derived ZnO nanoparticles

75%

Ali A., Dejene F., Swart H.

Open Physics

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2012

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vol. 10

|

issue 2

478-484

EN

Un-doped and Mn-doped ZnO nanoparticles were successfully synthesized in an ethanolic solution by using a sol-gel method. Material properties of the samples dependence on preparation conditions and Mn concentrations were investigated while other parameters were controlled to ensure reproducibility. It was observed that the structural properties, particle size, band gap, photoluminescence intensity and wavelength of maximum intensity were influenced by the amount of Mn ions present in the precursor. The XRD spectra for ZnO nanoparticles show the entire peaks corresponding to the various planes of wurtzite ZnO, indicating a single phase. The diffraction peaks of doped samples are slightly shifted to lower angles with an increase in the Mn ion concentration, signifying the expansion of the lattice constants and increase in the band gap of ZnO. All the samples show the absorption in the visible region. The absorbance spectra show that the excitonic absorption peak shifts towards the lower wavelength side with the Mn-doped ZnO nanoparticles. The PL spectra of undoped ZnO consist of UV emission at 388 nm and broad visible emission at 560 nm with varying relative peak intensities. The doping of ZnO with Mn quenches significantly the green emission while UV luminescence is slightly affected.

16

Synthesis and entomotoxicity assay of zinc and silica nanoparticles against Sitophilus granarius (Coleoptera: Curculionidae)

75%

Rouhani M., Samih M. A., Zarabi M., Beiki K., Gorji M., Aminizadeh M. R.

Journal of Plant Protection Research

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2019

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vol. 59

|

issue 1

17

THE STUDY OF ADSORPTION AND DESORPTION OF ANTIBIOTICS ON THE SURFACE OF NANOPARTICLES

75%

Biernat P., Borak B., Meler J., Karolewicz B.

Acta Poloniae Pharmaceutica - Drug Research

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2018

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vol. 75

|

issue 5

1215-1222

EN

Nanotechnology is a field that is gaining more and more importance in the modern world. It uses a particle size of between a few dozen to a few hundred nanometers, or 10-9 meters. It is noted that the use of nanospheres (balls with a diameter of from several to several hundred nm) as carriers of drugs gives an opportunity for their controlled and sustained release. (1,2) Nanospheres as a potential drug carrier for sustained release may enhance the effectiveness of antibiotics. In order to examine the effects of antibiotics with nanospheres an attempt was made to deposit on them three drugs differing in chemical structure. These were chloramphenicol, gentamicin and ceftazidime. The aim of this study was to determine the degree of adsorption of the drug on the surface of nanospheres and to examine the process of desorption from the surface of silica nanoparticles. The results of the study indicate that in the case of chloramphenicol it is essentially a process of chemisorption, and for gentamicin and ceftazidime both physical and chemical adsorption, without there being any clearly defined relationship between this two processes. The purpose of the nanospheres as drug carriers is to obtain controlled and prolonged exposure to the drug. The amount of adsorbed substance depends primarily on its structure. Ceftazidime, as the compound with the highest number of double bonds, and a large number of groups to form hydrogen bonds (carbonyl groups, amino groups), adsorbed to the greatest extent.

18

Synthesis of hydroxyapatite in a continuous reactor: a review

75%

Latocha J., Wojasiński M., Sobieszuk P., Ciach T.

Chemical and Process Engineering

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2018

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vol. 39

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issue 3

19

Influence of Different Plants Extracts on Silver Nanoparticles Green Synthesis

75%

Velgosová O., Mražíková A., Veselovský L., Willner J., Fornalczyk A.

Archives of Metallurgy and Materials

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2019

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vol. 64

|

issue 2

20

The bottom size of colloids

75%

Lyklema J.

|

2005

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vol. 53

|

issue 4

Refine search results

Nanostructuring of diamond films using self-assembled nanoparticles

ADVANCED CELLULOSIC MATERIALS

Simulation and control of nanoparticle size distribution in a high temperature reactor

Structural and morphological properties of HA-ZnO powders prepared for biomaterials

Photocatalytic degradation of malachite green dye using doped and undoped ZnS nanoparticles

Statistical Properties of a Polymer Chain in the Environment with Low Concentration of Nanoparticles

Characteristics of carbon nanomaterials and their application in the construction of potentiometric sensors – review

Interaction of unmodified and partially silylated nanosilica with red blood cells

Application of low-level laser radiation with TiO2, Ag/TiO2and S/TiO2on Streptococcus salivarius isolated from the oral cavity

A Monte Carlo study on dose enhancement and photon contamination production by various nanoparticles in electron mode of a medical linac

Molecular recognition of glyconanoparticles by RCA and E. coli K88 - designing transports for targeted therapy

Silver nanoparticles – possible applications and threats

Silver nanoparticle accumulation by aquatic organisms – neutron activation as a tool for the environmental fate of nanoparticles tracing

Cytotoxicity of thermo-responsive polymeric nanoparticles based on N-isopropylacrylamide for potential application as a bioscaffold