Rebar corrosion due to chlorides in synergy with sodium, potassium, and magnesium

The ability of steel reinforced concrete to withstand long service life is ensured by the strong binding between the concrete and the rebar. Although rebar corrosion deterioration in the presence of chlorides is well known, it is important to note that these anions are never present in isolation, i.e., other cations are also present within the exposed environment. Consequently, a study was conducted to investigate the rebar deterioration due to chlorides in the presence of different cations. A well-controlled laboratory experiment for assessing the corrosivity of sodium chloride, potassium chloride and magnesium chloride was conducted. The galvanostatic pulse technique was used to investigate the concrete-steel interfacial structure, which was modelled after a modified Randles circuit. Analysis revealed influences of the associated cations during the rebar corrosion process. A normalisation approach was used to compare chloride attacks on the rebar due to different salt solutions. Results suggest that chloride attacks in the presence of sodium cations are relatively corrosive

STUDY OF IN VITRO ANTI-OXIDANT AND ANTI-DIABETIC ACTIVITY BY MUSSAENDA MACROPHYLLA ROOT EXTRACTS

Objective: The systematic study of effective alternative anti-diabetic drugs has great importance to manage diabetes as well as other oxidative stress-related diseases. According to previous research, root and bark of Mussaenda macrophylla plant has anti-microbial, anti-coagulant, anti-inflammatory, and hepatoprotective activity. Ethnomedicinal data shows that Mussaenda macrophylla is used to treat diabetes as well as oxidative stress. The objective of this research is to investigate in vitro anti-diabetic and anti-oxidant activity of root extract of Mussaenda macrophylla. Methods: DPPH free radical scavenging assay was used to detect anti-oxidant potency of ethanol and methanol root extract of the plant and expressed as % of radicle inhibition. Anti-diabetic activity was determined by the glucose diffusion method using a glucose oxidase kit and results were expressed as mean±SD. Results: The ethanol root extract at the concentration of 50 mg/ml and 100 mg/ml showed better glucose diffusion inhibition than that of methanol extract at the same concentration on increasing time interval. Ethanol extract at the concentration 100 µg/ml displayed better DPPH scavenging activity (89.83±0.19 %) than that of methanol extract (86.61±0.75%). Conclusion: This study concluded that ethanol and methanol root extract of Mussenda macrophylla have potent anti-diabetic as well as anti-oxidant activity but further advance research is necessary in the animal model

ANALGESIC ACTIVITY OF BARK AND LEAVES OF FICUS RELIGIOSA L. FROM NEPAL

Objective: Because of adverse side effects, caused by NSAIDs, tolerance, and dependence induced by opiates, the use of these analgesic agents has not been successful in all cases. Therefore, alternative analgesic drugs from plant sources are the new target now days. The objective of this study was to evaluate the analgesic activity of ethanolic extracts of stem barks and leaves of Ficus religiosa. Methods: The analgesic activity of ethanolic extract of stem barks and leaves was evaluated in the Swiss albino mice model using acetic acid-induced writing response and Eddy’s hot plate method. Analgesic activity was demonstrated with the percentage inhibition of acetic acid induced writings and the percentage increased in latency time of paw licking. The potency of test extracts was compared with standard drug, Diclofenac. Results: Ethanolic extract of leaves and bark of F. religiosa showed potential analgesic activity from both methods. From Eddy’s hot plate model, it was observed that the percentage of increased latency time at 90 min by ethanolic extract of leaves and stem bark was found to be 70.81 % (8.54 min) and 70.78 % (8.53 min) respectively at a dose of 400 mg/kg. Both of these results are statistically significant (p<0.05) as compared to the test group. Furthermore, both of these extracts showed the dose-dependent and time-dependent increased in latency time and these results are compared to that of standard drug Diclofenac. Similarly, ethanolic extract of leaves and stem at 400 mg/kg significantly inhibited the number of writhings induced by acetic acid. The percentage inhibition of writhings by ethanolic extract of leaves at a dose of 400 mg/kg was 68.47 % which was similar to that of standard drug Diclofenac (68.47 %). However, ethanolic extract of bark showed relatively lower percentage inhibition (60.79 %) as compared to leaf extract and standard, but the result was significant as compared to that of the test group (p<0.05). Conclusion: Ethanolic extracts of F. religiosa stem bark and leaf possess both central and peripheral analgesic properties and these effects may be beneficial for the management of pain

ICAR: endoscopic skull‐base surgery

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Shifting the limits in wheat research and breeding using a fully annotated reference genome

Introduction: Wheat (Triticum aestivum L.) is the most widely cultivated crop on Earth, contributing about a fifth of the total calories consumed by humans. Consequently, wheat yields and production affect the global economy, and failed harvests can lead to social unrest. Breeders continuously strive to develop improved varieties by fine-tuning genetically complex yield and end-use quality parameters while maintaining stable yields and adapting the crop to regionally specific biotic and abiotic stresses. Rationale: Breeding efforts are limited by insufficient knowledge and understanding of wheat biology and the molecular basis of central agronomic traits. To meet the demands of human population growth, there is an urgent need for wheat research and breeding to accelerate genetic gain as well as to increase and protect wheat yield and quality traits. In other plant and animal species, access to a fully annotated and ordered genome sequence, including regulatory sequences and genome-diversity information, has promoted the development of systematic and more time-efficient approaches for the selection and understanding of important traits. Wheat has lagged behind, primarily owing to the challenges of assembling a genome that is more than five times as large as the human genome, polyploid, and complex, containing more than 85% repetitive DNA. To provide a foundation for improvement through molecular breeding, in 2005, the International Wheat Genome Sequencing Consortium set out to deliver a high-quality annotated reference genome sequence of bread wheat. Results: An annotated reference sequence representing the hexaploid bread wheat genome in the form of 21 chromosome-like sequence assemblies has now been delivered, giving access to 107,891 high-confidence genes, including their genomic context of regulatory sequences. This assembly enabled the discovery of tissue- and developmental stage–related gene coexpression networks using a transcriptome atlas representing all stages of wheat development. The dynamics of change in complex gene families involved in environmental adaptation and end-use quality were revealed at subgenome resolution and contextualized to known agronomic single-gene or quantitative trait loci. Aspects of the future value of the annotated assembly for molecular breeding and research were exemplarily illustrated by resolving the genetic basis of a quantitative trait locus conferring resistance to abiotic stress and insect damage as well as by serving as the basis for genome editing of the flowering-time trait. Conclusion: This annotated reference sequence of wheat is a resource that can now drive disruptive innovation in wheat improvement, as this community resource establishes the foundation for accelerating wheat research and application through improved understanding of wheat biology and genomics-assisted breeding. Importantly, the bioinformatics capacity developed for model-organism genomes will facilitate a better understanding of the wheat genome as a result of the high-quality chromosome-based genome assembly. By necessity, breeders work with the genome at the whole chromosome level, as each new cross involves the modification of genome-wide gene networks that control the expression of complex traits such as yield. With the annotated and ordered reference genome sequence in place, researchers and breeders can now easily access sequence-level information to precisely define the necessary changes in the genomes for breeding programs. This will be realized through the implementation of new DNA marker platforms and targeted breeding technologies, including genome editing

Fluorescence studies on erythrocyte membrane isolated from Plasmodium berghei infected mice

The erythrocyte host cell plays a key role in the well defined developmental stages of the malarial parasite growth and propagation in the erythrocyte cycle of malaria. The host cell serves the parasites by supplying metabolites and removing the catabolites produced by the obligatory parasites. It has been observed that the plasma membrane of the infected cells show a substantially higher fluidity probably due to the depletion of cholesterol content from the host cell. The protein component of the membrane is also modulated due to the insertion of new polypeptides of the parasitic origin, which confers upon it new antigenic properties. We have studied the membrane fraction isolated from mice erythrocytes infected with Plasmodium berghei using fluorescent probes like DPH, ANS and series of fluorenyl fatty acids, which permit depth dependent analysis of membrane. We have observed that there is a marked difference in the fluorescence emission wavelength maximum, the dissociation constant Kd of ANS when bound to normal and infected erythrocytes, though relatively small differences are observed in the fluorescence polarisation values of the two cell types. The fluorenyl fatty acids also show the differences when bound to normal and infected erythrocytes, indicating that either they are in a different environment or they have differing binding properties to the two cell types

ANTIOXIDANT AND ANTICANCER ACTIVITY OF METHANOLIC EXTRACT FROM STEPHANIA ELEGANS

Objective: The present work was aimed to investigate the in vitro antioxidant and anti-cancer activities of methanolic extract of Stephania elegans, an unexplored species from Menispermaceae family.Methods: The methanolic extract of S. elegans tubers was prepared and phytochemical screening and total phenolic content were analyzed by using standard methods. In vitro, antioxidant potential of methanolic extract was determined by 2-2'-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) and ferric reducing antioxidant power (FRAP) assays. Cytotoxicity against human breast cancer cell line, Michigan Cancer Foundation-7 type (MCF-7) was evaluated by 3-(4, 5 dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide) (MTT) assay.Results: Preliminary phytochemical screening revealed the presence of alkaloids, flavonoids, carbohydrates, tannins, terpenoids, steroids, and saponins in the methanolic extract of S. elegans tubers. The total phenolic content in the methanolic extract was 23.0±0.06 mg GAE/g (dry mass). As revealed by ABTS assay, the methanolic extract of plant tubers showed significant radical scavenging activity (IC50 41.66±0.015 μg/ml). The reducing power activity of the extract increased with the concentration of the extract. MTT assay indicated that S. elegans has potent cytotoxic activity towards MCF-7 cells (IC50 158.7±0.13 μg/ml).Conclusion: This is the first study demonstrating the antioxidant and anticancer capabilities of the methanolic extract of S. elegans. This study also provides a significant basis for further isolation and characterization of bioactive compounds from S. elegans

Rebar corrosion due to chlorides in the presence of different cations

Recent attention on effects of climate change in the Pacific island countries (PIC’s) have focused on a multitude of areas which are at risk in the Pacific region. These include food security, flora and fauna, land accessibility, groundwater contamination and so on. These aspects are essential for sustainable development of the small island states in the Pacific region. One issue, which appears synonymous with climate change in the Pacific is sea-level rise. The rising sea level can have detrimental effects on civil infrastructure since its intrusion further inland can lead to deterioration of nearby civil metallic infrastructure due to corrosion. Since metropolisation of major PIC’s are mainly near the sea or along coast line, this presents a significant problem within the overall paradigm of sustainable development. In this regards, a study was undertaken to investigate the influences of different chloride salts (i.e. NaCl, KCl, MgCl2) on the corrosion of steel re-inforcing bars (rebar’s) in concrete mortars. This study is important to understand structural health conditions, especially for foundations in ground, and to understand the corrosion intensities in the presence of different cations, which can be significantly controlled by groundwater migration. The galvanostatic pulse technique was used to evaluate the effect of varying chloride contents of different salts on rebar corrosion. Results from this study are presented in an attempt to provide a conceptual model for understanding the interaction of aforementioned salts with metallic infrastructure. A holistic discussion is presented which are important for sustainable development in the PIC’s