Nickel manganite-carbonized alginate composite for use as energy storage electrodes

Nickel-manganite is a versatile material used in many technology applications. One of the established uses is as a supercapacitor electrode. The advantage of this type of material is the abundance of required metals, compared to noble metals, the synthesis methods' simplicity, and high redox activity. Metal-oxide battery materials are usually combined with activated carbon to enhance the specific surface area and add to energy storage capacity via surface charge accumulation. In the current work, nickel manganite was synthesized via the sol-gel combustion synthesis method with glycine as fuel and nitrate ions as oxidizers. The post-combustion amorphous powder was calcined at temperatures between 300 and 800 °C. Powders were structurally characterized. Obtained materials were tested as energy storage electrodes in a three-electrode cell setup in 6 M KOH aqueous solution as electrolyte. Methods embedded in electrochemical characterization were cyclic voltammetry (CV), electric impedance spectroscopy (EIS) and constant current chronopotentiometry at different current densities to obtain galvanostatic charge-discharge (GCD) curves. Results show considerable charge storage activity, which can be ascribed to oxido reduction reactions of manganese ions and charge accumulation on the surface of the activated carbon

Humidity and Temperature Sensing of Mixed Nickel–Magnesium Spinel Ferrites

Temperature- and humidity-sensing properties were evaluated of NixMg1-x spinel ferrites (0 ≤ x ≤ 1) synthesized by a sol-gel combustion method using citric acid as fuel and nitrate ions as oxidizing agents. After the exothermic reaction, amorphous powders were calcined at 700 °C ollowed by characterization with XRD, FTIR, XPS, EDS and Raman spectroscopy and FESEM icroscopy. Synthesized powders were tested as humidity- and temperature-sensing materials in the form of thick films on interdigitated electrodes on alumina substrate in a climatic chamber. The physicochemical investigation of synthesized materials revealed a cubic spinel Fd3m phase, nanosized but agglomerated particles with a partially to completely inverse spinel structure with increasing Ni content. Ni0.1Mg0.9Fe2O4 showed the highest material constant (B30,90) value of 3747 K and temperature sensitivity (α) of −4.08%/K compared to pure magnesium ferrite (B30,90 value of 3426 K and α of −3.73%/K) and the highest average sensitivity towards humidity of 922 kΩ/%RH in the relative humidity (RH) range of 40–90% at the working temperature of 25 °C

Magnesium substitution with nickel and its influence on the sensing properties of MgFe2O4

Mixed spinel ferrites MgxNi1-xFe2O4 were synthesized via sol-gel combustion synthesis with citric acid as fuel, followed by calcination at 700 °C for 3 hours. Obtained powders were characterized via X-ray diffraction analysis (XRD), X-ray photoelectron (XPS), FTIR and Raman spectroscopy and FESEM microscopy. Elemental composition was examined via energy dispersive spectroscopy (EDS). Humidity sensing properties were tested by measuring AC impedance in a climactic chamber at 25 °C and in the relative humidity range of 40–90%. Temperature sensing properties were tested by measuring DC resistance at 40% RH in the temperature range 40–90 °C. Synthesized powders were proven to be pure spinel Fd 3m phase with spherical, slightly agglomerated particles. Substitution of Mg with Ni results in structural changes such as a change in inversion parameter and particle agglomeration, which influences sensing properties of the material. Results show that the sensing properties of magnesium ferrite can be improved by incorporating 10% of nickel in the spinel lattice structure. Mg0.9Ni0.1Fe2O4 exhibited higher temperature sensitivity and higher sensitivity towards humidity compared to MgFe2O4, while further substitution of Mg with Ni resulted in the decline of sensing properties, increase in particle size and agglomeration degree

THE INNER SHELL IONIZATION OF THE ATOM BY ELECTRONS UDC 539.183+544.17

Abstract. In this paper, the resonant processes of inner-shell ionization of some atoms, followed by the Auger decay of the created vacancy was considered. The analytical expression for the line profiles in the Auger-electron spectra was analyzed. The line shift in the Auger spectra of the rare gas atom inner-shells was also considered. Key words: Auger decay, line shift, inner-shell ionization. 1

Structural characterization of the nickel thin film deposited by glad technique

In this work, a columnar structure of nickel thin film has been obtained using an advanced deposition technique known as Glancing Angle Deposition. Nickel thin film was deposited on glass sample at the constant emission current of 100 mA. Glass sample was positioned 15 degrees with respect to the nickel vapor flux. The obtained nickel thin film was characterized by Force Modulation Atomic Force Microscopy and by Scanning Electron Microscopy. Analysis indicated that the formation of the columnar structure occurred at the film thickness of 1 μm, which was achieved for the deposition time of 3 hours. [Projekat Ministarstva nauke Republike Srbije, br. III45005

Patient–physician relationship in the aftermath of war

During the period of conflict that led to the dissolution of the former Yugoslavia, the Serbian healthcare system suffered greatly; as a result, relationships between physicians and their patients reached an all‐time low. After cessation of the various wars, a group of medical students attempted to assess the state of the patient–physician relationship in Serbia. Their study showed a relationship characterised by very meek patients and rather arrogant physicians. Empowered by their engagement, the medical students constructed a set of standards for achieving a proper patient–physician relationship; physicians should be capable of hearing and understanding patients, with the result that the ensuing empowerment can enable patients and physicians to create a tool for changing the relationship between both parties

Anticancer effect of novel luteolin capped gold nanoparticles selectively cytotoxic towards human cervical adenocarcinoma HeLa cells: An in vitro approach

Background: Although luteolin has been confirmed as potent anticancer agent, its potential application as therapeutic is limited by its water solubility. To overcome this shortcoming nanoparticle technology approach was applied. Owing to their proven low toxicity and the possibility to be easily functionalized gold nanoparticles (AuNP) were the nanosystem of choice used in this study. Novel luteolin capped gold nanoparticles (AuNPL) were synthesized and their anticancer effect towards human cervical adenocarcinoma HeLa cells was investigated in vitro. Methods: AuNPL were synthesized by reducing chloroauric acid by trisodium citrate with subsequent addition of luteoline during synthesis and their physicochemical characterization was done. AuNPL cytotoxicity against HeLa, human malignant melanoma A375, and normal human keratinocytes HaCaT cells was tested by MTT cell survival assay, and their IC50 values were determined. The capability of AuNPL to induce cell cycle arrest and apoptosis in HeLa cells were demonstrated by flow cytometry. The antioxidant activity of AuNPL was assessed by DPPH⋅ and ABTS⋅þ scavenging assays. Cytoprotective properties of AuNPL towards HaCaT cells were examined by measuring the physiological and H2O2 induced intracellular reactive oxygen species (ROS) levels using flow cytometry. Also, genotoxicity of AuNPL in HaCaT cells was investigated by the single cell alkaline comet assay. Results: Spherical AuNPL, stable in aqueous solution up to six months at 4 ◦C were obtained in the synthesis. The selectivity in the cytotoxic action of AuNPL on HeLa and A375 cancer cells compared with their cytotoxicity on normal keratinocytes HaCaT was observed. AuNPL exerted their cytotoxic activity against HeLa cells through accumulation of the cells in the subG1 phase of the cell cycle, inducing the apoptotic cell death mediated by the activation of caspase-3 − 8, and − 9. AuNPL antioxidative potential was confirmed by DPPH⋅ and ABTS⋅þ scavenging assays. IC50 concentration of AuNPL exerted cytoprotective effect against HaCaT cells by the significant reduction of the physiological intracellular ROS level. Additionally, AuNPL were shown as more cytoprotective towards HaCaT cells then luteolin due to the more successful elimination of H2O2 induced intracellular ROS. Moreover, nontoxic concentrations of AuNPL did not cause considerable DNA damage of HaCaT cells, indicating low genotoxicity of the nanoparticles

Intracranial Arteriovenous Malformations as a Possible Cause of Endocranial Bone Lesions and Associated Neurological Disorder

Endocranial bone lesions have attracted intensive scientific debate on their aetiology. In recent literature, the lesions were almost exclusively interpreted as of infectious origin. In this paper, we give new insight into the aetiology of endocranial lesions, distinguishing the lesions of vascular origin from those caused by tuberculosis or other conditions. The analysis is based on a rare case of a young female individual who displayed multiple endocranial lesions with serpens endocrania symmetrica' morphology. The lesions were associated with an uncommon branching pattern of the middle meningeal artery and marked side differences in teeth pathology. Postcranial skeleton showed signs of the left upper limb weakness. The macroscopic finding of the endocranial lesions along with the skeletal evidence of neurological damage, together with characteristic radiological and histological features, can lead to diagnosis of arteriovenous malformations. This study aims to improve understanding of the aetiology of endocranial bone lesions

Prospective analysis of gait characteristics in chronic inflammatory demyelinating polyradiculoneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a disorder that may lead to functional impairment, including gait abnormalities. Our aim was to analyze gait characteristics in patients with CIDP compared to healthy controls (HC). Moreover, we sought to determine changes of gait parameters after six-month follow-up period. Twenty-four patients with CIDP and 24 HCs performed basic walking task, dual-motor task, dual-mental task, and combined task using the same GAITRite system. Lower limb MRC-SS and lower limb INCAT disability score were assessed. Fourteen patients were retested after six months. Majority of gait parameters showed significant differences in all experimental conditions when compared between CIDP and HCs. The most consistent findings in CIDP were shorter stride length (SL), prolonged cycle time (CT) and double support time (DS), as well as increased variation of SL and of swing time (ST) (p lt 0.05). During follow-up, INCAT improved in nine (64.3%) of 14 patients and MRC-SS improved in eight (57.1%) patients. Six-month changes of CT and its variation during combined task significantly differentiated patients with improved vs. non-improved INCAT (p lt 0.05). In conclusion, patients with CIDP had slower gait with prolonged DS and with shorter SL compared to HCs. Increased variation of SL and of ST in CIDP may suggest a potential risk for instability and falls. Shorter CT duration and less CT variation during time correlated well with improvement in disability

Investigation of modified thin SnO2 layers treated by rapid thermal annealing by means of hollow cathode spectroscopy and AFM technique

By means of hollow cathode spectroscopy and atomic force microscopy the surface morphology and composition of SnO2 thin film, modified with hexamethyldisilazane after rapid thermal annealing treatment (800-1200 degrees C), are investigated. Formation of crystalline structure is suggested at lower temperatures. Depolimerization, destruction and dehydration are developed at temperatures of 1200 degrees C. It is shown that the rapid thermal annealing treatment could modify both the surface morphology and the composition of the layer, thus changing the adsorption ability of the sensing layer. The results confirm the ability of hollow cathode emission spectroscopy for depth profiling of new materials especially combined with standard techniques