Effect of heat treatment condition on the phase formation of YBa2Cu3O7-δ superconductor

Polycrystalline samples with the nominal composition YBa2Cu3O7-δ (Y-123) were prepared using the co-precipitation method. The effect of the calcination process (single and multiple calcinations) on the samples was investigated by using the four-point temperature-resistance measurement, x-ray diffraction (XRD) and field-emission scanning electron microscope (FESEM). This study is divided into two parts. For the first part, the obtained oxalate powder underwent two calcination processes at 900 °C for 12 h and 900 °C for 24 h, respectively. Then, the powders were pressed into pellets and sintered at 920 °C for 15 h with oxygen flow during the entire heat treatment. In the second part, only one calcination process was undertaken at 900 °C for 24 h before the sintering process in oxygen flow at 920 °C for 15 h. From the XRD patterns, all of the peaks were indexed to the Y-123 phase showing that this superconducting phase was already formed after the first calcination. The volume fraction of Y-123 of the samples with single calcination process was higher compared to multiple calcination processes. From the temperature-resistance measurement, all the samples showed metallic behavior in the normal state and a superconducting transition to zero resistance. The superconducting transition temperature, Tc, for the samples prepared in a single calcination process is higher than that of the multiple calcination processes

Stingless bee honey improves spatial memory in mice, probably associated with brain-derived neurotrophic factor (BDNF) and Inositol 1,4,5- triphosphate receptor type 1 (Itpr1) genes

This study was conducted to evaluate the effects of stingless bee honey (SBH) supplementation on memory and learning in mice. Despite many studies that show the benefits of honey on memory, reports on the nootropic effects of SBH are still lacking, and their underlying mechanism is still unclear. SBH is a honey produced by the bees in the tribe of Meliponini that exist in tropical countries. It features unique storage of honey collected in cerumen pots made of propolis. This SBH may offer a better prospect for therapeutic performance as the previous report identifies the presence of antioxidants that were greater than other honey produced by Apis sp. In this study, SBH was tested on Swiss albino mice following acute (7 days) and semichronic (35 days) supplementation. Experiments were then conducted using Morris water maze (MWM) behaviour analysis, RT-PCR for gene expression of mice striatum, and NMR for metabolomics analysis of the honey. Results indicate spatial working memory and spatial reference memory of mice were significantly improved in the honey-treated group compared with the control group. Improved memory consolidations were also observed in prolonged supplementation. Gene expression analyses of acutely treated mice demonstrated significant upregulation of BDNF and Itpr 1 genes that involve in synaptic function. NMR analysis also identified phenylalanine, an essential precursor for tyrosine that plays a role at the BDNF receptor. In conclusion, SBH supplementation for seven days at 2000 mg/kg, which is equivalent to a human dose of 162 mg/kg, showed strong capabilities to improve spatial working memory. And prolonged intake up to 35 days increased spatial reference memory in the mice model. The phenylalanine in SBH may have triggered the upregulation of BDNF genes in honey-treated mice and improved their spatial memory performance

Current strategies and perspectives in detection and control of basal stem rot of oil palm

The rapid expansion of oil palm (OP) has led to its emergence as a commodity of strategic global importance. Palm oil is used extensively in food and as a precursor for biodiesel. The oil generates export earnings and bolsters the economy of many countries, particularly Indonesia and Malaysia. However, oil palms are prone to basal stem rot (BSR) caused by Ganoderma boninense which is the most threatening disease of OP. The current control measures for BSR management including cultural practices, mechanical and chemical treatment have not proved satisfactory. Alternative control measures to overcome the G. boninense problem are focused on the use of biological control agents and many potential bioagents were identified with little proven practical application. Planting OP varieties resistant to G. boninense could provide the ideal long-term solution to basal stem rot. The total resistance of palms to G. boninense has not yet been reported, few examples of partial resistances have been observed. Importantly, basidiospores are now recognized as the method by which the disease is spread, and control methods require to be revaluated because of this phenomenon. Many methods developed to prevent the spread of the disease effectively are only tested at nursery levels and are only reported in the national journal inhibiting the development of useful techniques globally. The initial procedures employed by the fungus to infect the OP require consideration in terms of the physiology of the growth of the fungus and its possible control. This review assesses critically the progress that has been made in BSR development and management in OP.The authors thank the Ministry of Higher Education (MOHE) Malaysia for providing financial support under the project Fundamental Research Grant Scheme (FRGS/1/2019/STG05/UPM02/22) and University Putra Malaysia. We are also thankful to Dr Yuvarani Naidu from Malaysian Palm Oil Board for providing images of Basal Stem Rot disease symptoms from her personal collection. Professor Paterson is grateful for his second IOI Professorial Chair 2018/19.info:eu-repo/semantics/publishedVersio

Identification of differentially regulated genes in breast (MCF-7) and lung (H1299) cancer cell lines during Newcastle disease virus strain AF2240 infection

Newcastle disease virus (NDV), a member of Paramyxoviridae family is known for its selective oncogenic effects in cancer cells. Even though NDV infections in cancer cells were shown to result in cell death through apoptosis, the actual mechanism of NDV-induced cell death process has not been thoroughly investigated. Therefore, in the present study, we investigated the effects of infection of a local velogenic NDV strain, designated as AF2240, on gene and cell cycle regulation of cancer cells. Two different cancer cell lines; MCF-7 breast cancer cell line with wild type p53 status,and H1299, a non-small cell lung cancer (NSCLC) cell line with p53-null were used. At 1 MOI, NDV AF2240 infection resulted in cellular morphological changes as early as 3 HPI in both MCF-7 as well as H1299 cells. At this time, viral proteins were also began to be detectable via immunoblotting. The infection caused massive cell death via apoptosis in MCF-7 cells by 12 HPI. The lack of p53 tumor suppressor protein in H1299 led to reduced apoptosis in H1299 cells. The cells however died through necrosis after 12 hours post infection (HPI). These findings showed that NDV can induce apoptosis in both p53-dependent and p53-independent manner, although the former is more efficient. Despite the p53-dependency, EIF4A1, a member of the RNA helicase family is crucial in NDV-induced cell death. Overexpression of EIF4A1 led to increase in translation of viral proteins. The increase in NDV viral proteins caused cells to trigger cell cycle arrest via upregulation of p21Cip1 and p27Kip1. The present of high levels (more than 0.5 fold) of these cyclin dependent kinase inhibitors at early stages of infection caused ploidy increase in MCF-7. In H1299, growth arrest at G0/G1 phase was observed. Another important protein that was found to be involved in NDV-induced cancer cell killing was MBP-1. Due to the difference in the p53 status in MCF-7 versus H1299, the effects of MBP-1 regulation might be different. Since MBP-1 involves in both apoptotic as well as necrotic cell death pathways, the outcome of NDV infection in the cells were different. In MCF-7, NDV AF2240 infection caused massive apoptosis but not in H1299 cells. This study started with preparation of pure virus and cell lines. Then the cells were either infected with NDV or mock-infected using saline and media. The cells were then harvested at different post-infection period (3, 6, 9, and 12 hours) where unlysed cells were used in apoptosis analysis using TUNEL assay and Typan blue staining method as well as in cell cycle analysis. Whereas, RNA and total lysate from lysed cells were subjected to GeneFishing, Real-time PCR and Western blotting. Results obtained in this study showed that the outcome of NDV infection strongly depends on the genetic status of cell lines. This stresses the complexity of the pathways involve in NDV oncolytic properties. Nonetheless, our study has shed some light into further understanding of the effects of NDV on the gene and cell cycle regulation of MCF-7 and H1299 cells. Further studies however are needed in order to ensure the efficacy and efficiency of NDV as a potential anti-cancer agent for specific cancer types

Verification of H5 and IL-15 gene integrations in recombinant fowlpox viruses

Introduction of the chicken cytokine gene might trigger a stronger cellular mediated immune response in recombinant fowlpox viruses already carrying the avian influenza H5 gene. In order to ascertain that integrated H5 and IL-15 genes are stable in the previously constructed recombinant fowlpox viruses, PCR analyses were done after a few viral passages. Wild type fowlpox virus, recombinant fowlpox viruses co-expressing avian influenza H5 (rFWPV/H5) and recombinant fowlpox viruses co-expressing avian influenza H5 and chicken IL-15 cytokine (rFWPV/H5) were propagated in CEF cell culture. DNA genomic extractions were done prior to PCR analysis. Primer set targeting H5 and IL-15 confirmed the deduced sizes of both genes. Flanking primers further verified the stable integration of H5 and IL-15 genes in both recombinant viruses. This study confirms that H5 and IL-15 genes were stably present rFWPV/H5 and rFWPV/H5/IL-15. The current results allow future in vitro and in vivo characterisation of the recombinant viruses in triggering humoral and cellular immune responses

Antioxidant Activity, Total Phenolic and Flavonoid Content and LC–MS Profiling of Leaves Extracts of <i>Alstonia angustiloba</i>

Plants have a wide range of active compounds crucial in treating various diseases. Most people consume plants and herbals as an alternative medicine to improve their health and abilities. A. angustiloba extract showed antinematodal activity against Bursaphelenchus xylophilus, antitrypanosomal action against Trypanosoma brucei and anti-plasmodial activity against the chloroquine-resistant Plasmodium falciparum K1 strain. Moreover, it has demonstrated growth inhibitory properties towards several human cancer cell lines, such as MDA-MB-231, SKOV-3, HeLa, KB cells and A431. DPPH and ABTS assays were carried out to determine the antioxidant activity of the aqueous and 60% methanolic extract of A. angustiloba leaves. Moreover, total phenolic and flavonoid contents were quantified. The presence of potential active compounds was then screened using liquid chromatography coupled with a Q-TOF mass spectrometer (LC–MS) equipped with a dual electrospray ionisation (ESI) source. The EC50 values measured by DPPH for the 60% methanolic and aqueous extracts of A. angustiloba leaves were 80.38 and 94.11 µg/mL, respectively, and for the ABTS assays were 85.80 and 115.43 µg/mL, respectively. The 60% methanolic extract exhibited the highest value of total phenolic and total flavonoid (382.53 ± 15.00 mg GAE/g and 23.45 ± 1.04 mg QE/g), while the aqueous extract had the least value (301.17 ± 3.49 mg GAE/g and 9.73 ± 1.76 mg QE/g). The LC–MS analysis revealed the presence of 103 and 140 compounds in the aqueous and 60% methanolic extract, respectively. It consists of phenolic acids, flavonoids, alkaloids, amino acids, glycosides, alkaloids, etc. It can be concluded that the therapeutic action of this plant is derived from the presence of various active compounds; however, further research is necessary to determine its efficacy in treating diseases

Antioxidant Activity, Total Phenolic and Flavonoid Content and LC&ndash;MS Profiling of Leaves Extracts of Alstonia angustiloba

Plants have a wide range of active compounds crucial in treating various diseases. Most people consume plants and herbals as an alternative medicine to improve their health and abilities. A. angustiloba extract showed antinematodal activity against Bursaphelenchus xylophilus, antitrypanosomal action against Trypanosoma brucei and anti-plasmodial activity against the chloroquine-resistant Plasmodium falciparum K1 strain. Moreover, it has demonstrated growth inhibitory properties towards several human cancer cell lines, such as MDA-MB-231, SKOV-3, HeLa, KB cells and A431. DPPH and ABTS assays were carried out to determine the antioxidant activity of the aqueous and 60% methanolic extract of A. angustiloba leaves. Moreover, total phenolic and flavonoid contents were quantified. The presence of potential active compounds was then screened using liquid chromatography coupled with a Q-TOF mass spectrometer (LC&ndash;MS) equipped with a dual electrospray ionisation (ESI) source. The EC50 values measured by DPPH for the 60% methanolic and aqueous extracts of A. angustiloba leaves were 80.38 and 94.11 &micro;g/mL, respectively, and for the ABTS assays were 85.80 and 115.43 &micro;g/mL, respectively. The 60% methanolic extract exhibited the highest value of total phenolic and total flavonoid (382.53 &plusmn; 15.00 mg GAE/g and 23.45 &plusmn; 1.04 mg QE/g), while the aqueous extract had the least value (301.17 &plusmn; 3.49 mg GAE/g and 9.73 &plusmn; 1.76 mg QE/g). The LC&ndash;MS analysis revealed the presence of 103 and 140 compounds in the aqueous and 60% methanolic extract, respectively. It consists of phenolic acids, flavonoids, alkaloids, amino acids, glycosides, alkaloids, etc. It can be concluded that the therapeutic action of this plant is derived from the presence of various active compounds; however, further research is necessary to determine its efficacy in treating diseases

Isolation of Cellulose Nanocrystals from Banana Peel Using One-Pot Microwave and Mild Oxidative Hydrolysis System

The current investigation deals with the application of a one-pot system to facilitate the production of cellulose nanocrystals (CNCs) from banana peel by a combination of microwave pre-treatment and mild oxidative hydrolysis with hydrogen peroxide (H2O2, 0&ndash;30 wt%) and sulfuric acid (H2SO4, 0&ndash;10%). H2O2 causes decolorization of the banana peel suspension from dark brown to light yellow, while further treatment with H2SO4 produces a white suspension, indicating successful removal of the non-cellulosic components from the banana peel. This finding was further supported by Fourier Transform Infrared (FTIR) spectroscopic analysis, which showed the gradual disappearance of lignin and hemicellulose peaks with increasing H2O2 and H2SO4 concentrations. The CNCs has considerably high crystallinity, with the highest crystallinity (~85%) being obtained at 6% H2SO4. Therefore, CNCs obtained at 6% H2SO4 were selected for further characterization. Scanning Electron Microscope (SEM) analysis confirmed the disintegration of the cellulose fibres into small fragments after hydrolysis. Transmission Electron Microscope (TEM) and Atomic Force Microscope (AFM) analyses revealed the spherical shape of the CNCs with an average size of approximately 20 nm. The CNCs have good stability with zeta potential of &minus;42.9 mV. Findings from this study suggest that the combination of microwave pre-treatment and oxidative hydrolysis with 30 wt% H2O2 and 6% H2SO4, which is about 11 times lower than the commonly used H2SO4 concentration, is proven effective for the isolation of CNCs from banana peel. These observations are expected to provide insight into a facile and environmentally benign alternative to the conventional CNCs isolation method, using abundant and underutilized agricultural waste as feedstock

Antibacterial Activity of Hoya Diversifolia Ethanolic Leaves Extract

The rapid emergence of resistance bacteria toward various antibiotics may associate with higher medical cost and increase mortality rate. Hoya diversifolia was used to cure skin diseases and alleviate rheumatism pain. The aim of this study is to evaluate in vitro antibacterial properties of H. diversifolia ethanolicleaves extract against several Gram positive and Gram negative bacteria. The antibacterial study was determined based on pattern of inhibition zones using disc diffusion assay and also minimal inhibitory concentration (MIC). It is shown that the extract can inhibit the growth of methicillin-resistant Staphylococcus aureus,Escherichia coliandBacillus cereus.The lowest MIC values of extract were 25 mg/mL for MRSA and E. coli as well as 100 mg/mL for B. cereus at 24 and 48 hours of incubation period. The plant had potential to act as antibacterial agent that can be applied in pharmaceutical and cosmetic fields. © 2019 Oriental Scientific Publishing Company. All rights reserved