Unified methodology for characterisation of global fatigue damage evolution in adhesively bonded joints

This paper reports on the development of a methodology for evaluating the fatigue damage evolution in single and double lap adhesively bonded joints subjected to constant and variable fatigue loading. First, a methodology is developed to monitor the evolution of permanent deformation, stiffness degradation and hysteresis losses of single lap joints subjected to constant amplitude fatigue load. During the test, the global deformation of the adhesive joint is monitored using digital image correlation (DIC). A MATLAB code is developed to analyse and visualize the evolution in stiffness degradation and energy dissipation during the course of a complete fatigue test. Hereto ellipses are fitted to the hysteresis loops in the recorded load-deformation data. The slope of the main axis of the ellipse and its enclosed area are extracted to determine stiffness and dissipated energy, respectively. Next, the methodology is optimized for implementation during fatigue testing of double lap joints with different bond line thicknesses. The results of the experimental study reveal a distinct relation between stiffness degradation and increase in hysteresis losses with increasing number of fatigue cycles or thus increasing fatigue damage

Unified methodology for characterisation of global fatigue damage evolution in adhesively bonded joints

The present work concentrates on the development of a methodology for evaluating the fatigue performance of single and double lap adhesively bonded joints subjected to constant or variable fatigue loading. Firstly, a methodology was developed to monitor the evolution of permanent deformation, stiffness degradation and hysteresis losses of single lap joints subjected to constant amplitude fatigue load. Hereto, the global deformation of the adhesive joint was monitored using the digital image correlation technique (DIC). A MATLAB code was developed to evaluate and visualize the stiffness degradation and energy dissipation (hysteresis loops) occurring during a complete fatigue test. Secondly, this methodology was optimized to evaluate the properties of double lap joints with two different bond line thicknesses. The results of both constant and variable amplitude fatigue tests show the relation between stiffness degradation and increase in hysteresis losses with increase in number of fatigue cycles or thus fatigue damag

BOOSTING THE SKIN DELIVERY OF CURCUMIN THROUGH STEARIC ACID-ETHYL CELLULOSE BLEND HYBRID NANOCARRIERS-BASED APPROACH FOR MITIGATING PSORIASIS

Objective: Curcumin presents poor topical bioavailability when administered orally, which poses a major hurdle in its use as an effective therapy for the management of psoriasis. The present study reports the utilization of lipid-polymer hybrid nanoparticles (LPHNPs) for the topical delivery of curcumin which can be a potential approach for mitigating psoriasis. Methods: Curcumin-loaded LPHNPs were prepared by the emulsification solvent evaporation method and characterized. The optimized Curcumin-loaded LPHNPs (DLN-3) were further incorporated into 2% Carbopol 940 gels and evaluated for its therapeutic efficacy in the Imiquimod (IMQ)-induced psoriasis rat model. Results: The average particle size, polydispersity index, zeta potential, drug entrapment and loading efficiency for DLN-3 were found to be 200.9 nm, 0.342,-28.3 mV, 87.40±0.99% and 4.57±0.04%, respectively. FT-IR, DSC and XRD studies confirmed that all the components used for the formulation are compatible with each other, whereas SEM and TEM analysis affirmed the spherical shape of LPHNPs with a smooth surface. The in vitro drug release studies suggest that curcumin was released from the LPHNPs in a sustained manner over a period of 24 h via super case II transport mechanism. Results of in vitro skin permeation study revealed that 38.39±2.67% of curcumin permeated at 12 h across excised pig ear skin with a permeation flux of 18.74±3.59 µg/cm2/h. Further, in vivo evaluation and histopathological studies demonstrated that NLHG-1 hydrogels showed better therapeutic efficacy against the psoriatic skin lesions than the standard marketed gels. Conclusion: These results suggest that the developed LPHNPs have a superior ability to improve the skin penetration or accumulation of DLN-3 within psoriatic skin and offer a potential delivery system for the management of psoriasis

FORMULATION AND EVALUATION OF METFORMIN HYDROCHLORIDE LOADED FLOATING MICROSPHERES

Objective: The main objective of this study was to develop and evaluate the eudragit and HPMC coated metformin hydrochloride floating microspheres, in which HPMC helps in floating and eudragit as a coating material for a site-specific drug release in a controlled manner and the active moiety metformin used as anti-hyperglycemic agent. Methods: The floating microsphere was prepared by the solvent evaporation method incorporating metformin as a model drug. The prepared floating microsphere were characterized for particle size, %yield, drug loading and entrapment efficiency, compatibility study, %buoyancy, surface morphology and In vitro drug release and release kinetics. Results: The result metformin loaded floating microsphere was successfully prepared and the particle size range from 397±23.22 to 595±15.82 µm, the entrapment efficiency range from 83.49±1.33 to 60.02±1.65% and drug loading capacity range from 14.3±0.54 to 13.31±0.47% and %buoyancy range from 85.67±0.58 to 80.67±1.15%. The FT-IR and X-RD analysis confirmed that no any interaction between drug and excipient, and surface morphology confirmed those particles are sphere. The floating microsphere show maximum 96% drug release in pH 0.1N HCL and follow the Korsmeyer peppas model of the super case-2 transport mechanism. Conclusion: These results suggest that metformin loaded floating microspheres could be retain in stomach for long time and give site specific drug release in controlled manner

The Plant Ontology: A common reference ontology for plants

The Plant Ontology (PO) (http://www.plantontology.org) (Jaiswal et al., 2005; Avraham et al., 2008) was designed to facilitate cross-database querying and to foster consistent use of plant-specific terminology in annotation. As new data are generated from the ever-expanding list of plant genome projects, the need for a consistent, cross-taxon vocabulary has grown. To meet this need, the PO is being expanded to represent all plants. This is the first ontology designed to encompass anatomical structures as well as growth and developmental stages across such a broad taxonomic range. While other ontologies such as the Gene Ontology (GO) (The Gene Ontology Consortium, 2010) or Cell Type Ontology (CL) (Bard et al., 2005) cover all living organisms, they are confined to structures at the cellular level and below. The diversity of growth forms and life histories within plants presents a challenge, but also provides unique opportunities to study developmental and evolutionary homology across organisms

Cosmological Implications of Unimodular Gravity

We consider a model of gravity and matter fields which is invariant only under unimodular general coordinate transformations (GCT). The determinant of the metric is treated as a separate field which transforms as a scalar under unimodular GCT. Furthermore we also demand that the theory is invariant under a new global symmetry which we call generalized conformal invariance. We study the cosmological implications of the resulting theory. We show that this theory gives a fit to the high-z supernova data which is identical to the standard Big Bang model. Hence we require some other cosmological observations to test the validity of this model. We also consider some models which do not obey the generalized conformal invariance. In these models we can fit the supernova data without introducing the standard cosmological constant term. Furthermore these models introduce only one dark component and hence solve the coincidence problem of dark matter and dark energy.Comment: 18 pages, no figures, major revisions, substantial changes in analysis, results and conclusion

The Plant Ontology facilitates comparisons of plant development stages across species

The Plant Ontology (PO) is a community resource consisting of standardized terms, definitions, and logical relations describing plant structures and development stages, augmented by a large database of annotations from genomic and phenomic studies. This paper describes the structure of the ontology and the design principles we used in constructing PO terms for plant development stages. It also provides details of the methodology and rationale behind our revision and expansion of the PO to cover development stages for all plants, particularly the land plants (bryophytes through angiosperms). As a case study to illustrate the general approach, we examine variation in gene expression across embryo development stages in Arabidopsis and maize, demonstrating how the PO can be used to compare patterns of expression across stages and in developmentally different species. Although many genes appear to be active throughout embryo development, we identified a small set of uniquely expressed genes for each stage of embryo development and also between the two species. Evaluating the different sets of genes expressed during embryo development in Arabidopsis or maize may inform future studies of the divergent developmental pathways observed in monocotyledonous versus dicotyledonous species. The PO and its annotation databasemake plant data for any species more discoverable and accessible through common formats, thus providing support for applications in plant pathology, image analysis, and comparative development and evolution

A GLOBAL CONCERN ON ZIKA VIRUS: TRANSMISSION, DIAGNOSIS, PREVENTION, AND TREATMENT

Zika virus is a mosquito-transmitted flavivirus belongs to family Flaviviridae which becomes the focus of an ongoing pandemic and public health emergency all around the world. Zika virus has two lineages African and Asian. Mosquito-borne flavivirus is thought to replicate initially in dendritic cell and then spread to lymph nodes and then to the bloodstream. Zika virus was initially recognized in Uganda in 1947 in Monkeys through a method that observed yellow fever. It was later distinguished in people in 1952 in Uganda and the United Republic of Tanzania. The explosions of the zika virus disease have been recorded in Africa, The Americas, Asia, and The Pacific. Gillian-Berre syndrome and congenital malformation (microcephaly) suspected to be linked with Zika virus. The virus can only be confirmed through laboratory test on blood or other body fluids, such as urine, saliva or semen. No specific antiviral treatment for Zika virus disease exists. Treatment is aimed at relieving symptoms with rest, fluid and medications. WHO/PAHO encourages the countries to establish and maintain Zika Virus infections, detection, clinical management and community assurances strategies to reduce transmission of the virus. The future of Zika Virus spreading to other parts of the world is still unknown. Keywords: Zika Virus, flavivirus, Mosquito, Vaccine, Treatment, Microcephaly, WHO/PAHO