Synthesis and Characterization of Electro-Explosive Magnetic Nanoparticles for Biomedical Applications

Nowadays there are new magnetic nanostructures based on bioactive metals with low toxicity and high efficiency for a wide range of biomedical applications including drugs delivery, antimicrobial drugs design, cells' separation and contrasting. For such applications it is necessary to develop highly magnetic particles with less than100 nm in size. In the present study magnetic nanoparticles Fe, Fe[3]O[4] and bimetallic Cu/Fe with the average size of 60- 90 nm have been synthesized by electrical explosion of wire in an oxygen or argon atmosphere. The produced nanoparticles have been characterized with transmission electron microscopy, X-ray phase analysis, and nitrogen thermal desorption. The synthesized particles have shown antibacterial activity to gram-positive (S. aureus, MRSA) and gramnegative (E. coli, P. aeruginosa) bacteria. According to the cytological data Fe, Fe[3]O[4]and Cu/Fe nanoparticles have effectively inhibited viability of cancer cell lines Neuro-2a and J774. The obtained nanoparticles are promising for new antimicrobial drugs and antitumor agents' developmen

Synthesis and Characterization of Electro-Explosive Magnetic Nanoparticles for Biomedical Applications

Nowadays there are new magnetic nanostructures based on bioactive metals with low toxicity and high efficiency for a wide range of biomedical applications including drugs delivery, antimicrobial drugs design, cells' separation and contrasting. For such applications it is necessary to develop highly magnetic particles with less than100 nm in size. In the present study magnetic nanoparticles Fe, Fe[3]O[4] and bimetallic Cu/Fe with the average size of 60- 90 nm have been synthesized by electrical explosion of wire in an oxygen or argon atmosphere. The produced nanoparticles have been characterized with transmission electron microscopy, X-ray phase analysis, and nitrogen thermal desorption. The synthesized particles have shown antibacterial activity to gram-positive (S. aureus, MRSA) and gramnegative (E. coli, P. aeruginosa) bacteria. According to the cytological data Fe, Fe[3]O[4]and Cu/Fe nanoparticles have effectively inhibited viability of cancer cell lines Neuro-2a and J774. The obtained nanoparticles are promising for new antimicrobial drugs and antitumor agents' developmen

Preparation of nano/micro bimodal aluminum powder by electrical explosion of wires

Electrical explosion of aluminum wires has been shown to be a versatile method for the preparation of bimodal nano/micro powders. The energy input into the wire has been found to determine the relative content of fine and coarse particles in bimodal aluminum powders. The use of aluminum bimodal powders has been shown to be promising for the development of high flowability feedstocks for metal injection molding and material extrusion additive manufacturing

Chemical behaviour of Al/Cu nanoparticles in water

Bimetallic Al/Cu nanoparticles with Al/Cu composition 10:90, 20:80, 40:60 were produced by method of simultaneous electrical explosion of metal pairs in the argon atmosphere. Nanopowders containing 20% and 40% (mass) of aluminum interacted with water at 40–70 °C and formed composite particles that were porous structures of nanopetal pseudoboehmite with nanosized copper-containing inclusions inside. Aluminum in nanopowder with Al/Cu composition 10:90 did not react with water, as far as it is in the phase of intermetallic compounds СuAl2 and Сu4Al9. Nanocomposite produced can be used as an active component of antibacterial agents

Indifference

The matter of indifference is always relevant. Almost everyone has ever experienced it in relation to the difficulties of other people, even to the loved ones. Perhaps, a man is organized in such a way that firstly he is oriented on solving his own problems and only then on difficulties of close people. But you will not spend a lot of time and money on being responsive as it is more important to be kind, compassionate, ready to share the warmth of your soul with people in need.Тема равнодушия актуальна во все времена. Вероятно, каждый из нас хоть раз проявлял равнодушие по отношению к трудностям близких. Возможно, человек так устроен, что он склонен сначала решить собственные проблемы, а неприятности близких откладывает на второй план. Скорее всего, так мы просто пытаемся найти оправдание нашей слабости, нежеланию оказать внимание и поддержку близким людям. Отзывчивость тесно связана со способностью проявлять милосердие, сострадать. Иметь доброе сердце – не значит тратить много денег. Гораздо важнее отдавать теплоту своей души, уважать, ценить – всё это умения отзывчивого человека

Synthesis of Ti–Al bimodal powder for high flowability feedstock by electrical explosion of wires

In this research, Ti–Al bimodal powders were produced by simultaneous electrical explosion of titanium and aluminum wires. The resulting powders were used to prepare powder–polymer feedstocks. Material characterization involving X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and melt flow index (MFI) determination were carried out to characterize bimodal powders obtained and evaluate the influence of the powder composition on the feedstock flowability. The bimodal distribution of particles in powders has been found to be achieved at a current density of 1.2 × 107 A/cm2 (the rate of energy input is 56.5 J/µs). An increase in the current density to 1.6 × 107 A/cm2 leads to a decrease in the content of micron particles and turning into a monomodal particle size distribution. The use of bimodal powders for powder–polymer feedstocks allows to achieve higher MFI values compared with monomodal powders. In addition, the use of electroexplosive synthesis of bimodal powders makes it possible to achieve a homogeneous distribution of micro- and nanoparticles in the feedstock

Search for ∆S = 2 nonleptonic hyperon decays Ω − → Σ 0 π − and Ω − → nK −

Using (27.12 ± 0.14) × 108ψ(3686) events collected by the BESIII detector at the center-of-mass energy of s = 3.686 GeV, we search for the first time for two nonleptonic hyperon decays that change strangeness by two units, Ω− → Σ0π− and Ω− → nK−. No significant signal is observed. The upper limits on their decay branching fractions are determined to be B(Ω− → Σ0π−) < 5.4 × 10−4 and B(Ω− → nK−) < 2.4 × 10−4 at the 90% confidence level

Observation of ψ (3686) → Ω − K + Ξ ¯ 0 + c. c

Using (27.12 ± 0.14) × 108ψ(3686) events collected with the BESIII detector at BEPCII, the decay of ψ(3686) →Ω−K+Ξ¯0 + c.c. is observed for the first time. The branching fraction of this decay is measured to be Bψ3686→Ω−K+Ξ¯0+c.c. = (2.78 ± 0.40 ± 0.18) × 10−6, where the first uncertainty is statistical and the second is systematic. Possible baryon excited states are searched for in this decay, but no evident intermediate state is observed with the current sample size

Study of η ′ → π + π − l + l − decays at BESIII

With a sample of (10087 ± 44) × 106J/ψ events accumulated with the BESIII detector, we analyze the decays η′ → π+π−l+l−(l = e, μ) via the process J/ψ → γη′. The branching fractions are measured to be B(η′ → π+π−e+e−) = (2.45 ± 0.02(stat.) ± 0.08(syst.)) × 10−3 and B(η′ → π+π−μ+μ−) = (2.16 ± 0.12(stat.) ± 0.06(syst.)) × 10−5, and the ratio is Bη′→π+π−e+e−Bη′→π+π−μ+μ−=113.4±0.9stat.±3.7syst.. In addition, by combining the η′ → π+π−e+e− and η′ → π+π−μ+μ− decays, the slope parameter of the electromagnetic transition form factor is measured to be bη′ = 1.30 ± 0.19 (GeV/c2)−2, which is consistent with previous measurements from BESIII and theoretical predictions from the VMD model. The asymmetry in the angle between the π+π− and l+l− decay planes, which has the potential to reveal the CP-violation originating from an unconventional electric dipole transition, is also investigated. The asymmetry parameters are determined to be ACPη′→π+π−e+e−=−0.21±0.73stat.±0.01syst.% and ACPη′→π+π−μ+μ−=0.62±4.71stat.±0.08syst.%, implying that no evidence of CP-violation is observed at the present statistics. Finally, an axion-like particle is searched for via the decay η′ → π+π−a, a → e+e−, and upper limits of the branching fractions are presented for the mass assumptions of the axion-like particle in the range of 0 − 500 MeV/c2

Measurement of Born cross section of e + e − → Σ + Σ ¯ − at center-of-mass energies between 3.510 and 4.951 GeV

Using 24.1 fb−1 of e+e− collision data collected with the BESIII detector at the BEPCII collider, the Born cross sections and effective form factors of the e+e−→Σ+Σ¯− reaction are measured. The measurements are performed at center-of-mass energies ranging from 3.510 to 4.951 GeV. No significant evidence for the decay of the charmonium(-like) states, ψ(3770), ψ(4040), ψ(4160), Y(4230), Y(4360), ψ(4415), and Y(4660), into a Σ+Σ¯− final state is observed. Consequently, upper limits for the products of the branching fractions and the electronic partial widths at the 90% confidence level are reported for these decays