Magnesium-based implants (MBIs) have recently attracted great attention in bone regeneration due to elastic modulus similar to bone. Nevertheless, the degradation rate and hydrogen release of MBIs in ...the body have to be tackled for practical applications. In the present study, we present a metal-organic framework (MOF) nanoplates to reduce the degradation rate of AZ91 magnesium alloy. Zeolitic imidazolate frameworks (ZIF-8) with a specific surface area of 1789 m
g
were prepared by solvothermal methods, and after dispersion in a chitosan solution (10% w/w), the suspension was electrospun on the surface of AZ91 alloy. Studying the degradation rate in simulated body fluid (SBF) by electrochemical analysis including potentiodynamic polarization and electrochemical impedance spectroscopy reveals that the degradation rate of the surface-modified implants decreases by ~ 80% as compared with the unmodified specimens. The reduced alkalization of the physiological environment and hydrogen release due to the implant degradation are shown. In vitro studies by fibroblasts and MG63 osteosarcoma cells exhibit improved cell adhesion and viability. The mechanisms behind the improved degradation resistance and enhanced bioactivity are presented and discussed. Surface modification of MBIs by MOF-chitosan coatings is a promising strategy to control the biodegradation of magnesium implants for bone regeneration.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The present study deals with designing and synthesizing novel dyes using the drug combination of edaravone and azo compounds which can be used as an indicator for anions and cations. The desired ...product synthesis was accomplished
via
a two-step process involving diazotizing the aromatic amines followed by the resultant salts coupling with edaravone. The resulting dyes were obtained with high yields under mild conditions. The structures of the dyes were identified with UV-vis, FT-IR,
1
H NMR and
13
C NMR spectra and CHN analysis. To investigate the solvatochromism effect, the interaction of different solvents with the selected dyes was evaluated using several parameters including the dielectric constant, refractive index, hydrogen bond donating ability, hydrogen bond accepting ability and dipolarity/polarizability scale. To achieve deep understanding about the stability and geometrical characteristics of the azo-hydrazo tautomers of the synthesized dyes and their UV-visible spectra prediction, some DFT calculations were also carried out on the synthesized dyes. The antibacterial activities of some synthesized compounds were also evaluated using the disk diffusion method. The results revealed different activity of the selected synthesized dyes for antibacterial tests against selected Gram positive and Gram negative bacteria.
The present study deals with designing and synthesizing novel dyes using the drug combination of edaravone and azo compounds which can be used as an indicator for anions and cations.
Full text
Available for:
IJS, KILJ, NUK, UL, UM, UPUK
A method to significantly increase the gain and reduce the mutual coupling of microstrip multiple‐intput multiple‐output (MIMO) antenna based on metamaterial concept is presented. The μ‐negative and ...ε‐negative features of the proposed modified peace‐logo planar metamaterial (MPLPM) and two‐sided MPLPM (TSMPLPM) structures are calculated. The antenna structure consists of eight MPLPM slabs and two TSMPLPM, which are embedded in azimuth plane of a MIMO antenna vertically. The dimensions of MIMO antenna are 28 × 16 × 6.3 mm3 at 40 GHz. As a result, a compact MIMO antenna is simulated in comparison with primary microstrip structures. The corresponding return‐loss of the antenna is better than 10 dB over 34.5 to 45.5 GHz for Ka‐band applications. Good consent between the measured and simulated result is tacked. The maximum simulated gain of the structure is 15.5 dB at 40 GHz, creating a maximum gain improvement of 11.5 dB in comparison with a MIMO antenna without any metamaterial combinations. The value of the insertion‐loss (isolation) is 33 dB, which has improved by more than 25 dB compared to the conventional sample.
Full text
Available for:
FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
A method to significantly increase the gain and isolation of a wideband multiple‐input multiple‐output (MIMO) antenna using metamaterial structures is reported. The proposed metamaterial medium ...includes just one wall and one superstrate, which are fixed in xz and xy planes of the MIMO antenna, respectively. The dimensions of the proposed MIMO antenna are 13×13×3.5 mm3 at 30 GHz. A comparison between a simulated MIMO antenna and a conventional microstrip antenna demonstrates the good performance of the proposed metamaterial environment. The corresponding return‐loss of the antenna is better than 10 dB over 28–32 GHz for 5G applications. The maximum simulated gain of the antenna is 17.1 dB at 30 GHz, generating a maximum gain enhancement of 11.8 dB in comparison with a MIMO antenna without any metamaterial structures. The isolation (insertion‐loss) is 36.7 dB at 30 GHz, which has improved by more than 29.4 dB compared to the conventional one.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Purpose
Cyclophosphamide is an alkylating agent with nephrotoxicity that constrains its clinical application. Berberine is an isoquinoline derivative alkaloid with biological functions like ...antioxidant and anti-inflammatory. The current research intended to examine the nephroprotective impacts of berberine against cyclophosphamide-stimulated nephrotoxicity.
Methods
Forty animal subjects were randomly separated into five categories of control (Group I), cyclophosphamide (200 mg/kg, i.p., on 7th day) (Group II), and groups III and IV that received berberine 50 and 100 mg/kg orally for seven days and a single injection of cyclophosphamide on 7th day. Group V as berberine (100 mg/kg, alone). On day 8, blood samples were drawn from the retro-orbital sinus to determine serum levels of blood urea nitrogen (BUN), creatinine (Cr), neutrophil gelatinase-associated lipocalin (NGAL), and kidney injury molecule-1 (KIM-1) as biomarkers for kidney injury. Nitric oxide (NO), malondialdehyde (MDA) and glutathione (GSH) levels, catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) activities as oxidative stress factors, tumor necrosis factor-α (TNF-α) and interleukin 1 beta (IL-1β) levels as inflammatory mediators were assessed in kidney tissue.
Results
The results of this study demonstrated that berberine was able to protect remarkably the kidney from CP-induced injury through decreasing the level of BUN, Cr, NGAL, KIM-1, NO, MDA TNF-α, IL-1β and increasing the level of GSH, CAT, SOD, and GPx activities.
Conclusion
Berberine may be employed as a natural agent to prevent cyclophosphamide-induced nephrotoxicity through anti-oxidant and anti-inflammatory effects.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract
The desulphurization of hydrocarbon fuels with high sulphur content and a wide variety of sulphur‐containing compounds brings significant challenges. In the present work, the non‐catalytic ...desulphurization of vacuum gas oil (VGO) and natural gas condensate mixed fuel has been investigated. In this regard, ozone was employed as the oxidant in a bubble column gas–liquid contactor, and an extraction step was further incorporated. The effects of the oxidation reactor scheme, ozonation time, and extraction with different solvents, applying pre‐ and post‐extraction strategies (i.e., ozonation/extraction/extraction and extraction/ozonation/extraction), have been studied. It was found that pre‐extraction of mixed fuel increases the oxidative desulphurization (ODS) efficiency due to the removal of light sulphur‐containing compounds (SCCs). N‐methyl‐2‐pyrrolidone (NMP) has been found to be the most effective extraction agent, removing 44% of sulphur by pure extraction and 77.4% by ozonation + extraction. However, in terms of fuel loss, dimethylformamide (DMF) performs better than NMP, and it has been shown to be the most appropriate solvent for achieving a 90% desulphurization ratio. Finally, it was found that the applied procedure could effectively remove the wide range of SCCs, especially refractive components such as benzothiophene (BT) and dibenzothiophene (DBT).
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
ABSTRACTSAR (Synthetic Aperture Radar) satellite interferometry is a helpful remote sensing technique for large areas analyses and monitoring, especially where the study area is difficult to access ...for practical or for legal reasons. As a result, the use of these techniques has significantly increased over the past three decades. Among the available different satellite constellations displaying different spatial and temporal resolutions, COSMO-SkyMed of the Italian Space Agency (ASI) represents a cutting-edge reality. COSMO-SkyMed constellation, launched in 2007 by ASI, is a valuable Earth observation tool that provides all-weather, day-and-night imaging capabilities with high resolution and a short revisit time. In this study, we produced an atlas for the entire Italian peninsula using two parameters (R-Index and Percentage of measurability of movement), in order to evaluate the quality and a-priori applicability of satellite interferometry data collected by the COSMO-SkyMed constellation. The atlas was obtained by means of the implementation of different model builders in the GIS (Geographical Information Systems) environment, providing a semi-automatic way to generate the above-mentioned outputs. The R-Index describes the likelihood of detecting Permanent Scatterers in mountainous areas, while the Percentage of measurability of movement indicates the percentage of real motion that interferometry can detect at a certain point in the analyzed region. A high-detail Digital Terrain Model (DTM) has been used to identify the most suitable areas for satellite interferometry monitoring and studying. The results of our analysis showed that the R-Index and the Percentage of measurability of movement could be used to pre-evaluate the quality of satellite interferometry data collected by the COSMO-SkyMed constellation. This research has important implications for disaster response, environmental monitoring, and scientific research and is one of a few cases in the world in which a unified representation for an entire country is provided.
A method to significantly increase the gain of a bow‐tie antenna based on metamaterial concept is presented. The μ‐negative feature of the proposed two‐sided planar metamaterial (TSPM) structure is ...investigated by retrieving its constitutive parameters from the S‐parameters. The proposed structure consists of six slabs that are loaded with a 3 × 3 array of TSPM unit cells, which are embedded in azimuth plane of a modified bow‐tie antenna vertically. The TSPM unit cells provide a medium of low effective permeability. The dimensions of the slabs are 30.6 × 20.6 mm2 at 7 GHz. To show the adaptability of the proposed high‐gain antenna, the structure was designed to cover H‐band applications (6‐8 GHz). Consequently, a small antenna is designed in comparison with initial bow‐tie structures. The corresponding return loss of the antenna is better than 10 dB over 6 to 8 GHz. The proposed metamaterial antenna was manufactured and its characteristics measured to verify the proposed idea. Good agreement between the measured and simulated data is obtained. Maximum gain measured of the antenna is 10.21 dB at 7.5 GHz, constituting a maximum gain enhancement of 7 dB for H‐band in comparison with a bow‐tie antenna without any metamaterial structures.
Full text
Available for:
FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
Biodegradable polymer nanocomposites (BPNCs) are advanced materials that have gained significant attention over the past 20 years due to their advantages over conventional polymers. BPNCs are ...eco-friendly, cost-effective, contamination-resistant, and tailorable for specific applications. Nevertheless, their usage is limited due to their unsatisfactory physical and mechanical properties. To improve these properties, nanofillers are incorporated into natural polymer matrices, to enhance mechanical durability, biodegradability, electrical conductivity, dielectric, and thermal properties. Despite the significant advances in the development of BPNCs over the last decades, our understanding of their dielectric, thermal, and electrical conductivity is still far from complete. This review paper aims to provide comprehensive insights into the fundamental principles behind these properties, the main synthesis, and characterization methods, and their functionality and performance. Moreover, the role of nanofillers in strength, permeability, thermal stability, biodegradability, heat transport, and electrical conductivity is discussed. Additionally, the paper explores the applications, challenges, and opportunities of BPNCs for electronic devices, thermal management, and food packaging. Finally, this paper highlights the benefits of BPNCs as biodegradable and biodecomposable functional materials to replace traditional plastics. Finally, the contemporary industrial advances based on an overview of the main stakeholders and recently commercialized products are addressed.
Leaching of nitrogen (N) and phosphorus (P) from agricultural lands can cause serious environmental problems such as eutrophication. The objective of this study was to investigate the impacts of ...biochar application, tillage practices, and irrigation systems on nitrate and dissolved phosphorus (DP) concentrations in subsurface drainage water and grain yield of winter wheat using a strip-split plot design with 3 replications. Irrigation at three different levels (flood (
I
fl
), furrow (
I
fu
), and sprinkler (
I
s
) systems) considered as main factor, tillage at two levels (reduced tillage (
T
r
) and conventional systems (
T
c
)) as subplot factor, and bagasse biochar at two levels (without biochar (
B
0
) and 20 ton ha
−1
biochar (
B
1
)) as sub-subplot factor. Polyvinyl chloride (PVC) standpipes were used in each sub-subplot to collect leachate water at 100-cm depth. The results indicated that irrigation had significant effects on yield, collected water volume (CWV), nitrate, and DP concentrations (
P
< 0.01). Interaction of tillage and irrigation was significant for grain yield (
P
< 0.05). Biochar application only caused a significant decrease in nitrate concentration under sprinkler irrigation (
P
< 0.05), while no significant impact was observed under flood and furrow irrigation systems. Under sprinkler irrigation, the total nitrate collected in the PVC standpipes decreased by 37.51 and 34.29% compared with flood and furrow irrigations, respectively. Biochar application reduced the total nitrate collected by 16.84%, while difference among tillage treatments was negligible (4.51%). The total DP collected under sprinkler irrigation was lower in comparison with flood and furrow irrigations by 42.24 and 38.76%, respectively. Biochar application reduced the total DP collected by 10.84%, while reduced tillage increased the total DP collected by 8.90% compared with the conventional tillage.
PDF
