Self-consistent variational theory for globules

A self-consistent variational theory for globules based on the uniform expansion method is presented. This method, first introduced by Edwards and Singh to estimate the size of a self-avoiding chain, is restricted to a good solvent regime, where two-body repulsion leads to chain swelling. We extend the variational method to a poor solvent regime where the balance between the two-body attractive and the three-body repulsive interactions leads to contraction of the chain to form a globule. By employing the Ginzburg criterion, we recover the correct scaling for the $\theta$-temperature. The introduction of the three-body interaction term in the variational scheme recovers the correct scaling for the two important length scales in the globule - its overall size $R$, and the thermal blob size $\xi_{T}$. Since these two length scales follow very different statistics - Gaussian on length scales $\xi_{T}$, and space filling on length scale $R$ - our approach extends the validity of the uniform expansion method to non-uniform contraction rendering it applicable to polymeric systems with attractive interactions. We present one such application by studying the Rayleigh instability of polyelectrolyte globules in poor solvents. At a critical fraction of charged monomers, $f_c$, along the chain backbone, we observe a clear indication of a first-order transition from a globular state at small $f$, to a stretched state at large $f$; in the intermediate regime the bistable equilibrium between these two states shows the existence of a pearl-necklace structure.Comment: 7 pages, 1 figur

Self-reported “communication technology” usage in patients attending a cardiology outpatient clinic in a remote regional hospital

Peer reviewedPublisher PD

Legal skills: Ensuring ‘appy students

Law has been a little slow off the mark in the UK when it comes to the world of mobile applications (apps). In an environment where students spend more time using mobile applications than they do browsing the internet, the authors were keen to take their Learnmore website to the next stage by developing an app for law students. The Learnmore website (part of the Lawbore suite of resources from City University) has received much attention for its quirky visuals, multimedia learning tools and winning marriage of librarian and student generated content. With an ultimate aim of easing the transition between A-levels and degree and making the ‘building blocks’ of legal skills more interesting. Emily and Sanmeet secured substantial funding from JISC after a call for universities to create mobile apps from existing content, teaming up with a colleague in City University's Human Computer Interaction and Design department. The app was to be designed to help students learn essential legal skills in an innovative way, employing more interaction than was possible via the web. The emphasis on video content meant an early decision to fix on iPad rather than iPhone as the tool for mobile learning. The JISC funding paid for the services of a developer to help bring their ideas to life. This paper looks at the transformation from standard wiki to mobile application; focusing on the process of developing the concept for the app and the major milestones, as well as providing an insight into the expected challenges along the way. These included: working in a multidisciplinary team, communication of ideas, recognising the differences required in design for an app as opposed to a website and managing conflicting visions. The team motto was that creating an app cannot be simply a re-skinning process; but a re-working of content to to ensure a truly effective learning resource

A STUDY ON ANTIOXIDANT AND ANTI-AGING PROPERTIES OF FEW MEDICINAL PLANTS

Objective: The present study was undertaken to appraise the antioxidant and antiaging properties of some important medicinal plants like Syzygium cumini L. (Jamun, the Indian Blackberry), Tinospora cordifolia L. (Giloy) and Trigonella foenum-graecum L. (Methi).Methods: The methanolic extracts of these plants were prepared, incubated with Pheochromocytoma (PC-12) cells and total antioxidant potential of these plants was determined by 2, 2-diphenylpicrylhydrazyl (DPPH) and Ferric reducing ability of plasma (FRAP) assay. Lipid peroxidation assay was also performed to compare the free radical generating potential of these plants. Lipofuscin estimation was done in methanolic extracts of these plants to check which extract can reduce the lipofuscin accumulation in cells which is an anti-aging parameter.Results: The highest inhibition of DPPH radical and ferric reducing ability (FRAP assay) was observed in methanolic extract of Syzygium cumini leaves followed by Trigonella foenum-graecum leaves and lowest inhibition was shown by Tinospora cordifolia leaf extracts. Lipid peroxidation assay done by determining the amount of Malondialdehyde(MDA) formed and highest levels of MDA was produced by Tinospora cordifolia leaf extracts followed by Trigonella foenum-graecum leaf extracts and lowest values were obtained were from Syzygium cumini leaf extracts. The anti-aging parameter which is a determination of lipofuscin pigments in PC-12 cells treated with methanolic extracts of different plants was also examined. Highest accumulation of lipofuscin pigment was observed in cells treated with Tinospora cordifolia leaf extracts followed by Trigonella foenum-graecum leaf extracts and lowest values were obtained were from Syzygium cumini leaf extracts.Conclusion: The results of these findings revealed that the plants which have highest antioxidant potential could be a potent source of anti-aging drugs.Â

Early results on the use of chitosan-N-acetylcysteine (Lacrimera®) in the management of dry eye disease of varied etiology

PurposeTo evaluate the effect of once daily administration of chitosan-N-acetylcysteine (Lacrimera®) in the management of dry eye disease (DED).MethodsEighteen patients (3 male, 15 female) aged 25–86 years (mean 61.1) and suffering from moderate to severe DED with superficial punctate keratitis (SPK) were retrospectively evaluated after a trial of Lacrimera® drops (1 drop in the morning for 5 days only). All the patients were using other artificial tears before the treatment. All lubricants were stopped, and Lacrimera® was started instead. Slit-lamp examination and images were taken before and at 1 and 3 weeks follow-up after the treatment. The subjective (Ocular Surface Disease Index, OSDI) and objective (Oxford Grading System, OGS) evaluation was recorded. A paired student’s t test was performed to analyse the data.ResultsAt baseline, the SPK grade was I to IV (OGS) and the OSDI ranged from 25 to 71.4. Fifteen patients showed a statistically significant (p < 0.0001) improvement in OGS and the OSDI at 3 weeks post-treatment. Three patients showed no improvement.ConclusionsA single-dose instillation of chitosan-N-acetylcysteine for five consecutive days improved signs and symptoms in patients affected from DED from a variety of causes, who were refractory to standard treatment with lubricants. Given its posology, the absence of side effects and the results obtained Lacrimera® should be taken into consideration as a viable option in patients with moderate to severe DED

TLC Separation of Closely Related Amino Acids

761-76

Taste acceptance in squirrel monkeys (Saimiri sciureus)

Six squirrel monkeys were presented with solutions representing the four primary tastes. The solutions included various concentrations of glucose or sodium saccharine (sweet), sodium chloride (salty), citric acid (sour), and quinine sulfate or sucrose octaacetate (bitter). A 24 hr two-bottle choice technique was employed. Amount of food, water, and solution consumed every 24 hr was recorded. The results showed that the maximum intake for glucose solution was with the 5.0% concentration, although maximum caloric intake was with the 1.25% concentration where there was a potentiation of food intake. Water was preferred over sodium saccharine at three of the four concentrations which were tested, and water was preferred over or equally to the concentrations of sodium chloride and citric acid that were used. However, quinine sulfate and sucrose octaacetate were preferred over or equally to water at most of the concentrations which were tested

A Cephalometric Comparative Study for Upper Airway Dimensions in Different Craniofacial Growth Patterns

AIM AND OBJECTIVES: To compare different craniofacial patterns with pharyngeal widths. In OSA (Obstructive Sleep Apnea) patients, a mutual association between the pharyngeal structures and the dentofacial patterns has been suggested. The present study was performed to compare the nasopharynx, oropharynx and hypopharynx dimensions of persons with hypodivergent, normodivegent and hyperdivergent facial types and to predict and to facilitate treatment for OSA patients.Hypothesis: The Null hypothesis for the study was that there is no difference between the upper airway for patients with different growth pattern.MATERIALS AND METHODS: The sample comprised 60 patients divided into three groups: hypodivergent (n=20), normodivergent (n=20), and hyperdivergent (n=20) according to Jarabak’s ratio and FH-MP angle, which were used to compare the soft tissue airway dimensions. The statistical analysis was performed using Student’s t-Test, one way ANOVA (analysis of variance) and LSD (Least significant difference) test.RESULT: Overall narrower anteroposterior pharyngeal dimension was found in the hyperdivergent group as compared to the normodivergent group. Whereas, the superior part of upper pharyngeal width in the subjects with hypodivergent growth pattern was significantly narrower than in normal growth pattern groups.CONCLUSION: In hyperdivergent patients, the narrower anterioposterior dimension of the airway may be due to the skeletal features common to such patients, i.e., posterior vertical maxillary excess, posterior position and decreased mandibular size. The variations of the upper airway may be attributed to the horizontal and vertical growth patterns. Upper airway obstruction and later on OSA may be predisposed by skeletal deficiency