International study on <i>Artemia</i> : 15. Effect of light intensity on hatching rate of <i>Artemia</i> cysts from different geographical origin

Artemia cysts from 4 geographical strains were incubated under standard hatching rates increased with increasing light intensities. The light-intensity threshold at which the maximal hatching rate was attained, varied from strain to strain. Differences in light sensitivity between the Artemia strains studied can, at least partly, be attributed to variation in chorion characteristics. The hypothesis is discussed that light might act as a diapause inhibitor in marine and freshwater branchiopods

Oblikovanje i vrednovanje plutajućih uljnih mikrozrnaca loratadina s produljenim zadržavanjem u želucu

Gastro retentive controlled release system of loratadine was formulated to increase the residence time in stomach and to modulate the release behaviour of the drug. Oil entrapped floating microbeads prepared by emulsion gelation method were optimized by 23 factorial design and a polymer ratio of 2.5:1.5 (pectin: sodium alginate) by mass, 15% (m/v) of oil (mineral oil or castor oil) and 0.45 mol L-1 calcium chloride solution were selected as the optimized processing conditions for the desired buoyancy and physical stability. In vitro drug release in fed state conditions demonstrated sustained release of loratadine for 8 h that best fitted the Peppas model with n < 0.45. The ethylcellulose coating on microbeads optimized by 22 factorial design resulted in controlled release formulation of loratadine that provided zero-order release for 8 h.U radu je opisana priprava plutajućih mikrozrnaca za kontrolirano oslobađanje loratadina metodom želiranja emulzije. Mikrozrnca sadrže ulja, a njihovo zadržavanje u želucu je produljeno. Priprava mikrozrnaca je optimirana 23 faktorijalnim dizajnom. Pripravci optimalne sposobnosti plutanja i stabilnosti dobiveni su uz omjer masa pektina i natrijevog alginata 2,5:1,5, udio mineralnog ulja ili ulja kastora 15% (m/v) i koncentraciju kalcijevog klorida 0,45 mol L1. Iz tih se mikrozrnaca loratadin oslobađa in vitro tijekom 8 h, a oslobađanje slijedi Peppasov model ako je n < 0,45. Mikrozrnca presvučena etilcelulozom optimirana 22 faktorijalnim dizajnom slijede kinetiku nultog reda tijekom 8 h

Identification of plastic constitutive parameters at large deformations from three dimensional displacement fields

The aim of this paper is to provide a general procedure to extract the constitutive parameters of a plasticity model starting from displacement measurements and using the Virtual Fields Method. This is a classical inverse problem which has been already investigated in the literature, however several new features are developed here. First of all the procedure applies to a general three-dimensional displacement field which leads to large plastic deformations, no assumptions are made such as plane stress or plane strain although only pressure-independent plasticity is considered. Moreover the equilibrium equation is written in terms of the deviatoric stress tensor that can be directly computed from the strain field without iterations. Thanks to this, the identification routine is much faster compared to other inverse methods such as finite element updating. The proposed method can be a valid tool to study complex phenomena which involve severe plastic deformation and where the state of stress is completely triaxial, e.g. strain localization or necking occurrence. The procedure has been validated using a three dimensional displacement field obtained from a simulated experiment. The main potentialities as well as a first sensitivity study on the influence of measurement errors are illustrated

Prophylactic human papillomavirus vaccination against cervical cancer : a summarised resource for clinicians

No abstract available.http://www.sajgo.co.za/index.php/sajg

Priprava i in vitro karakterizacija mikrosfera amoksicilina dobivenih metodom sušenja sprejom

The purpose of the present study was to design mucoadhesive chitosan microspheres containing amoxycillin. Chitosan microspheres with a small particle size and good sphericity were prepared by a spray-drying method followed by chemical treatment with a chemical crosslinking agent (glutaraldehyde). Parameters affecting the extent of crosslinking were the crosslinking time and the concentration of the crosslinker agent. Crosslinked spray-dried chitosan microspheres were analyzed for their morphological aspects, particle size, drug entrapment efficiency, swelling percent and in vitro drug release. Batch M4 with a drug polymer ratio of 1:2, dissolved in minimum concentration of acetic acid solution treated with glutraldehyde, was found to be optimal giving controlled drug release for 10 h. It was found that both the increase of glutaraldehyde concentration and crosslinking duration decreased the swelling capacity of chitosan microspheres. This could be directly correlated to drug release from the microspheres.Cilj ovog rada bio je priprava mukoadhezivnih kitozanskih mikrosfera amoksicilina. Mikrosfere male veličine čestica i dobre sferičnosti pripravljene su metodom sušenja sprejom, te obradom s glutaraldehidom kao sredstvom za umrežavanje. Stupanj umrežavanja ovisio je o vremenu umrežavanja i koncentraciji sredstva za umrežavanje. Umreženim kitozanskim mikrosferama određen je oblik, veličina čestica, količina uklopljenog lijeka, postotak bubrenja i in vitro oslobađanje ljekovite tvari. Pripravak M4 s optimalnim svojstvima i kontroliranim oslobađanjem amoksicilina tijekom 10 sati pripravljen je pomoću smjese polimera omjera 1:2 otopljenih u razrijeđenoj octenoj kiselini, te umreženih pomoću glutraldehida. Povećanje koncentracije glutaraldehida i trajanja umrežavanja smanjuje sposobnost bubrenja kitozanskih mikrosfera, što je u izravnoj korelaciji s oslobađanjem lijeka iz mikročestica

Are social norms associated with smoking in French university students? A survey report on smoking correlates

<p>Abstract</p> <p>Background</p> <p>Knowledge of the correlates of smoking is a first step to successful prevention interventions. The social norms theory hypothesises that students' smoking behaviour is linked to their perception of norms for use of tobacco. This study was designed to test the theory that smoking is associated with perceived norms, controlling for other correlates of smoking.</p> <p>Methods</p> <p>In a pencil-and-paper questionnaire, 721 second-year students in sociology, medicine, foreign language or nursing studies estimated the number of cigarettes usually smoked in a month. 31 additional covariates were included as potential predictors of tobacco use. Multiple imputation was used to deal with missing values among covariates. The strength of the association of each variable with tobacco use was quantified by the inclusion frequencies of the variable in 1000 bootstrap sample backward selections. Being a smoker and the number of cigarettes smoked by smokers were modelled separately.</p> <p>Results</p> <p>We retain 8 variables to predict the risk of smoking and 6 to predict the quantities smoked by smokers. The risk of being a smoker is increased by cannabis use, binge drinking, being unsupportive of smoke-free universities, perceived friends' approval of regular smoking, positive perceptions about tobacco, a high perceived prevalence of smoking among friends, reporting not being disturbed by people smoking in the university, and being female. The quantity of cigarettes smoked by smokers is greater for smokers reporting never being disturbed by smoke in the university, unsupportive of smoke-free universities, perceiving that their friends approve of regular smoking, having more negative beliefs about the tobacco industry, being sociology students and being among the older students.</p> <p>Conclusion</p> <p>Other substance use, injunctive norms (friends' approval) and descriptive norms (friends' smoking prevalence) are associated with tobacco use.</p> <p>University-based prevention campaigns should take multiple substance use into account and focus on the norms most likely to have an impact on student smoking.</p

Carbon capture: Whole system experimental and theoretical modeling investigation of the optimal CO<inf>2</inf> stream composition in the carbon capture and sequestration chain

Rapid increase in emissions of greenhouse gases (GHGs) has become a major concern to the global community. This is associated with the rapid growth in population and corresponding increase in energy demand. Combustion of fossil fuels accounts for the majority of CO2 emissions. Coal is used mostly for electricity generation, for instance, about 85.5% of coal (produced and imported) in the United 459Kingdom was used for electricity generation in 2011 [1]. Coal-fired power plants are therefore the largest stationary source of CO2