The effect of Sr concentration on bioactivity and biocompatibility of sol–gel derived glasses based on CaO–SrO–SiO2–P2O5 quaternary system

In the present study, sol–gel derived glasses based on CaO–SrO–SiO₂–P₂O₅ system were prepared and the effect of Sr concentration on in vitro bioactivity and cellular properties of the glasses were investigated. SrO was substituted for CaO in the glass formula up to 10 mol% and in vitro bioactivity of the samples was evaluated by soaking them in simulated body fluid followed by structural characterization using XRD, FTIR and SEM techniques. The effects of various glass compositions on proliferation and differentiation of osteoblastic cells were also evaluated. The results showed that the substitution of Sr for Ca in the glass composition retarded formation of apatite layer onto the glass surfaces. Morphologies of the apatite layers were also different in which abundance of the crystals decreased with increasing Sr concentration. The bioactive glasses did not exert cytotoxic effect on the cells, however the proliferation and alkaline phosphatase activity of the cells on the samples containing low doses of Sr were higher than those of control and the samples with high dose of Sr. Glass specimen with 5 mol% of Sr exhibited appropriate bioactivity with optimal cell proliferation and ALP activity.     

Plastic antibodies as chemical sensor material for atrazine detection

Self-organization of monomers around template molecules, in bulk MIP generation, leads to selective molecular imprints with high sensitivity. Employing the host–guest chemistry, novel artificial receptors were fabricated via in situ MIP synthesis directly on gold electrodes of piezoelectric transducers (quartz crystal microbalance, QCM). The resultant label-free and robust biomimetic sensing material shows reversible as well as selective sensor responses for chlorotriazines moieties with minor structural differences. A detection limit of 20 ppb for atrazine was attained while showing selectivity up to 9 times higher than its metabolites des-ethyl-atrazine (DEA), des-isopropyl-atrazine (DIA), des-ethyl-des-isopropyl-atrazine (DEDIA) and structural analogues like simazine (SIM) and propazine (PRO). Furthermore, imprinted nanoparticles give linear characteristics over the wide range and show no saturation effects in comparison to bulk materials.     

Environmental cost of energy consumption and biodiesel as a solution (case study: Iran)

ABSTRACT

More than 8.5 million people live in Tehran, the capital of Iran, with 111 pollutant days during 2016. Based on Iranian 2016 energy balance sheet, more than 76% of SPM was emitted by gas oil combustion. To determine the main pollutant fuel-consuming sector, the amount of gas oil consumption and SPM production are investigated. Therefore, the transportation and power plant sectors are determined as the main gas oil users with 51.1% and 30.5% of its total consumption. Next, the reduced external cost of implementing biodiesel instead of gas oil for mobile and fixed sources is deliberated. Finally, by comparing the external cost of gas oil consumption and Iran's gross domestic production in 2016, it is revealed that by replacing gas oil with biofuels, 3.935 billion dollars (0.95% of gross domestic production of Iran in 2016) can be reduced.     

Genes and Longevity of Lifespan

Aging is a complex process indicated by low energy levels, declined physiological activity, stress induced loss of homeostasis leading to the risk of diseases and mortality. Recent developments in medical sciences and an increased availability of nutritional requirements has significantly increased the average human lifespan worldwide. Several environmental and physiological factors contribute to the aging process. However, about 40% human life expectancy is inherited among generations, many lifespan associated genes, genetic mechanisms and pathways have been demonstrated during last decades. In the present review, we have evaluated many human genes and their non-human orthologs established for their role in the regulation of lifespan. The study has included more than fifty genes reported in the literature for their contributions to the longevity of life. Intact genomic DNA is essential for the life activities at the level of cell, tissue, and organ. Nucleic acids are vulnerable to oxidative stress, chemotherapies, and exposure to radiations. Efficient DNA repair mechanisms are essential for the maintenance of genomic integrity, damaged DNA is not replicated and transferred to next generations rather the presence of deleterious DNA initiates signaling cascades leading to the cell cycle arrest or apoptosis. DNA modifications, DNA methylation, histone methylation, histone acetylation and DNA damage can eventually lead towards apoptosis. The importance of calorie restriction therapy in the extension of lifespan has also been discussed. The role of pathways involved in the regulation of lifespan such as DAF-16/FOXO (forkhead box protein O1), TOR and JNK pathways has also been particularized. The study provides an updated account of genetic factors associated with the extended lifespan and their interactive contributory role with cellular pathways.     

Green fabricated CuO nanobullets via Olea europaea leaf extract shows auspicious antimicrobial potential

In present investigation, copper oxide (CuO) nanostructures have been prepared via green chemistry. Olea europaea leaf extract act as strong chelating agent for tailoring physical as well as bio‐medical characteristics of CuO at the nano‐size. Physical characterisation such as scanning electron microscope analysis depicts the formation of homogenised spherical shape nanoparticles (NPs) with average size of 42 nm. X‐ray diffraction and Fourier transform infrared spectroscopy further confirmed the crystalline pure phase and monoclinic structure. High performance liquid chromatography (HPLC) testing is performed to evaluate the relative concentration of bioactive molecules in the O. europaea leaf extract. From HPLC results capping action of organic molecules around CuO‐NPs is hypothesised. The antimicrobial potency of biosynthesised CuO‐NPs have been evaluated using colony forming unit (CFU) counting assay and disc diffusion method which shows a significant zone of inhibition against bacterial and fungal strains may be highly potential for future antimicrobial pharmaceutics. Furthermore, reduction of various precursors by plant extract will reduce environmental impact over chemical synthesis.Inspec keywords: copper compounds, antibacterial activity, biochemistry, nanoparticles, nanomedicine, biomedical materials, chromatographyOther keywords: CuO, size 42 nm, chemical synthesis, antimicrobial pharmaceutics, bacterial strain, fungal strain, disc diffusion method, colony forming unit counting assay, biosynthesised CuO‐NP, bioactive molecules, high‐performance liquid chromatography testing, monoclinic structure, crystalline pure phase, Fourier transform infrared spectroscopy, X‐ray diffraction, homogenised spherical shape nanoparticles, scanning electron microscope analysis, CuO biomedical characteristics, chelating agent, green fabricated CuO nanobullets, green chemistry, copper oxide nanostructures, antimicrobial potential, Olea europaea leaf extract     

Optimization of Lipase Production by Response Surface Methodology and Its Application for Efficient Biodegradation of Polyester vylon-200

Catalysis Letters - Lipase-mediated polymer degradation is a robust alternative approach to conventional methods due to biocompatibility and mild conditions. In the present study, response surface...     

Green Synthesis of Chromium Oxide Nanoparticles for Antibacterial,Antioxidant Anticancer,and Biocompatibility Activities

This study deals with the green synthesis of chromium oxide (Cr₂O₃) nanoparticles using a leaf extract of Abutilon indicum (L.) Sweet as a reducing and capping agent. Different characterization techniques were used to characterize the synthesized nanoparticles such as X-ray diffraction (XRD), Scanning electron microscope (SEM), Transmission electron microscope (TEM), Energy-dispersive X-ray (EDX), Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible (UV-VIS) spectroscopy. The X-ray diffraction technique confirmed the purity and crystallinity of the Cr₂O₃ nanoparticles. The average size of the nanoparticles ranged from 17 to 42 nm. The antibacterial activity of the green synthesized nanoparticles was evaluated against four different bacterial strains, E. coli, S. aureus, B. bronchiseptica, and B. subtilis using agar well diffusion and a live/dead staining assay. The anticancer activities were determined against Michigan Cancer Foundation-7 (MCF-7) cancer cells using MTT and a live/dead staining assay. Antioxidant activity was investigated in the linoleic acid system. Moreover, the cytobiocompatibility was analyzed against the Vero cell lines using MTT and a live/dead staining assay. The results demonstrated that the green synthesized Cr₂O₃ nanoparticles exhibited superior antibacterial activity in terms of zones of inhibition (ZOIs) against Gram-positive and Gram-negative bacteria compared to plant extracts and chemically synthesized Cr₂O₃ nanoparticles (commercial), but comparable to the standard drug (Leflox). The green synthesized Cr₂O₃ nanoparticles exhibited significant anticancer and antioxidant activities against MCF-7 cancerous cells and the linoleic acid system, respectively, compared to chemically synthesized Cr₂O₃ nanoparticles. Moreover, cytobiocompatibility analysis displayed that they presented excellent biocompatibility with Vero cell lines than that of chemically synthesized Cr₂O₃ nanoparticles. These results suggest that the green synthesized Cr₂O₃ nanoparticles’ enhanced biological activities might be attributed to a synergetic effect. Hence, green synthesized Cr₂O₃ nanoparticles could prove to be promising candidates for future biomedical applications.     

Pollen morphological variation of Berberis L. from Pakistan and its systematic importance

Due to overlapping and diverse morphological characters, Berberis is among the most taxonomically complex genera. Palynology is one of the taxonomic tools for delimitation and identification of complex species. In this study, pollens of 10 Berberis species were analyzed through light and scanning electron microscopy. Qualitative as well as quantitative features (pollen shape, size, presence or absence of colpi, colpi length and width, exine thickness, ornamentation, pollen class, aperture, and polar–equatorial ratio) were measured. Five species were observed to have colpate (pantocolpate) with elongated ends, radially symmetrical, isopolar, monads, and psilate‐regulate pollens. In polar view, six pollen were spheroidal, two were ovoid, one spherical, and one oblate. Similarly, variation in pollen length was prominent and the largest pollen on polar view was recorded for B. psodoumbellata 60–65 μm (62.4 ± 0.9), while the smallest one was observed for B. lycium 29–35 μm (32.2 ± 1). The observed variation in both quantitative and qualitative features were important in taxonomic identification. This shows that palynological characters are helpful in identification of Berberis genus at the species level.     

Inhibition of mild steel corrosion in presence of fatty acid imidazolines in hydrochloric acid

The corrosive behavior of mild steel in 1M HCl solutions containing selected imidazolines of fatty acids with C₇-C₁₇ was investigated using weight-loss method, potentiodynamic polarization technique and scanning elecron microscopy. The results obtained revealed that all the studied imidazolines are effective in reducing corrosion of mild steel in HCl media. The adsorption of the inhibitors on the mild steel surface obeys Langmuir’s adsorption isotherm. The thermodynamic parameters of adsorption deduced reveal a strong interaction and spontaneous adsorption of inhibitors on the mild steel surface. The influence of inhibitor concentration, solution temperature, immersion time and acid concentration on the corrosion of mild steel has also been investigated. Scanning electron microscopy(SEM) of mild steels samples is performed to show adsorption of inhibitors on metal surface. Potentiodynamic polarization data showed that the compounds studied are mixed type inhibitors in the acid solution. Original Russian Text ? M.A. Quaraishi, M.Z.A. Rafiquee, Nidhi Saxena, Sadaf Khan, 2008, published in Zashchita Metallov, 2008, Vol. 44, No. 1, pp. 99–106.     

A modelling and simulation based process for dependable systems design

Complex real-time system design needs to address dependability requirements, such as safety, reliability, and security. We introduce a modelling and simulation based approach which allows for the analysis and prediction of dependability constraints. Dependability can be improved by making use of fault tolerance techniques. The de-facto example, in the real-time system literature, of a pump control system in a mining environment is used to demonstrate our model-based approach. In particular, the system is modelled using the Discrete EVent system Specification (DEVS) formalism, and then extended to incorporate fault tolerance mechanisms. The modularity of the DEVS formalism facilitates this extension. The simulation demonstrates that the employed fault tolerance techniques are effective. That is, the system performs satisfactorily despite the presence of faults. This approach also makes it possible to make an informed choice between different fault tolerance techniques. Performance metrics are used to measure the reliability and safety of the system, and to evaluate the dependability achieved by the design. In our model-based development process, modelling, simulation and eventual deployment of the system are seamlessly integrated.