SUSTAINED RELEASE ARTEMETHER-LOADED SOLID LIPID MICROPARTICLES, BASED ON SOLIDIFIED REVERSE MICELLAR SOLUTION (SRMS)

Objectives: To prepare and evaluate sustained release artemether-loaded SLMs based on SRMS Material and methods: SRMS, consisting of mixtures of Phospholipon® 90H (P90H) and Softisan® 154 (1:1, 2:1 and 1:2) were formulated and characterized using differential scanning calorimetry (DSC). The SRMS were used to formulate artemether-loaded SLMs by melt homogenization. The SLMs were characterized based on particle size and morphology, pH stability, encapsulation efficiency (EE%) and loading capacity. In vitro release was carried out in simulated intestinal fluid (SIF, pH 7.5). Results: Thermograms of the SRMS (1:1, 2:1 and 1:2) showed sharp endothermic peaks at 65.5, 64.4 and 62.3 oC respectively. Maximum EE% of 70.00 ± 1.50 % was obtained for SLMs formulated with SRMS 1:1 and 1 % artemether. Loading capacity ranged from 5.67 to 17.90 g drug/100 g lipid. In vitro release showed about 80 to 84 % drug release at 7 h. Particle size of artemether-loaded SLMs ranged from 18.60 ± 0.09 to 34.80 ± 0.30 µm. The pH decreased significantly at 60 days from 6 to 4.8 for batch A2 formulated with SRMS 2:1 and 3 % artemether (p < 0.05). Conclusion: artemether-loaded SLMs based on SRMS had good sustained release properties and could be used once daily in order to enhance patient's compliance.   Key words: Malaria, artemether, SRMS, lipids, sustained release SLMs Â

Ascertaining the Overall Occurrence of Dental Fluorosis in Students of Selected Secondary Schools in Rivers State

Public health places a premium on understanding the amount of fluoride in potable water and other toothpastes, as well as how it affects skeletal and dental tissues to cause fluorosis. Fluorosis is, however, poorly understood and known in Nigeria. The goal of this research was to Ascertain the Overall Occurrence of Dental Fluorosis in Students of Selected Secondary Schools in Rivers State. A cross-sectional survey of 541 students from selected secondary schools in Rivers State who were between the ages of 9 and 17 was carried out. All students present at school on the day of data collection had their mouths examined by oral health professionals as part of a quasi-experimental method. Each subject was supported by a torch light while seated on a chair, and their teeth were examined for dental fluorosis in their wet state. The presence of dental fluorosis and the severity of it were documented using Dean's Dental Fluorosis. The presence of dental fluorosis and the severity of it were documented using Dean's Dental Fluorosis. (358) Dental fluorosis impacted 66.17% of the students, varying in severity from very mild to severe cases

Thermal Conversion of Guanylurea Dicyanamide into Graphitic Carbon Nitride via Prototype CNx Precursors

Guanylurea dicyanamide, [(H2N)C(-O)NHC(NH2)2][N(CN)2], has been synthesized by ion exchange reaction in aqueous solution and structurally characterized by single-crystal X-ray diffraction (C2/c, a = 2249.0(5) pm, b = 483.9(1) pm, c = 1382.4(3) pm, β = 99.49(3)°, V = 1483.8(5) × 106 pm3, T = 130 K). The thermal behavior of the molecular salt has been studied by thermal analysis, temperature-programmed X-ray powder diffraction, FTIR spectroscopy, and mass spectrometry between room temperature and 823 K. The results were interpreted on a molecular level in terms of a sequence of thermally induced addition, cyclization, and elimination reactions. As a consequence, melamine (2,4,6-triamino-1,3,5-triazine) is formed with concomitant loss of HNCO. Further condensation of melamine yields the prototypic CNx precursor melem (2,6,10-triamino-s-heptazine, C6N7(NH2)3), which alongside varying amounts of directly formed CNxHy material transforms into layered CNxHy phases without significant integration of oxygen into the core framework owing to the evaporation of HNCO. Thus, further evidence can be added to melamine and its condensation product melem acting as “key intermediates” in the synthetic pathway toward graphitic CNxHy materials, whose exact constitution is still a point at issue. Due to the characteristic formation process and hydrogen content a close relationship with the polymer melon is evident. In particular, the thermal transformation of guanylurea dicyanamide clearly demonstrates that the formation of volatile compounds such as HNCO during thermal decomposition may render a large variety of previously not considered molecular compounds suitable CNx precursors despite the presence of oxygen in the starting material

Structural matters in HTSC; the origin and form of stripe organization and checker boarding

The paper deals with the controversial charge and spin self-organization phenomena in the HTSC cuprates, of which neutron, X-ray, STM and ARPES experiments give complementary, sometimes apparently contradictory glimpses. The examination has been set in the context of the boson-fermion, negative-U understanding of HTSC advocated over many years by the author. Stripe models are developed which are 2q in nature and diagonal in form. For such a geometry to be compatible with the data rests upon both the spin and charge arrays being face-centred. Various special doping concentrations are closely looked at, in particular p = 0.1836 or 9/49, which is associated with the maximization of the superconducting condensation energy and the termination of the pseudogap regime. The stripe models are dictated by real space organization of the holes, whereas the dispersionless checkerboarding is interpreted in terms of correlation driven collapse of normal Fermi surface behaviour and response functions. The incommensurate spin diffraction below the resonance energy is seen as in no way expressing spin-wave physics or Fermi surface nesting, but is driven by charge and strain (Jahn-Teller) considerations, and it stands virtually without dispersion. The apparent dispersion comes from the downward dispersion of the resonance peak, and the growth of a further incoherent commensurate peak ensuing from the falling level of charge stripe organization under excitation.Comment: 49 pages with 8 figure

Causal and associational language in observational health research: A systematic evaluation.

This is the final version. Available from Oxford University Press via the DOI in this record. Data, data analysis code, and materials are available on the Open Science Framework project https://osf.io/jtdaz/.We estimated the degree to which language used in the high profile medical/public health/epidemiology literature implied causality using language linking exposures to outcomes and action recommendations; examined disconnects between language and recommendations; identified the most common linking phrases; and estimated how strongly linking phrases imply causality. We searched and screened for 1,170 articles from 18 high-profile journals (65 per journal) published from 2010-2019. Based on written framing and systematic guidance, three reviewers rated the degree of causality implied in abstracts and full text for exposure/outcome linking language and action recommendations. Reviewers rated the causal implication of exposure/outcome linking language as None (no causal implication) in 13.8%, Weak 34.2%, Moderate 33.2%, and Strong 18.7% of abstracts. The implied causality of action recommendations was higher than the implied causality of linking sentences for 44.5% or commensurate for 40.3% of articles. The most common linking word in abstracts was "associate" (45.7%). Reviewers' ratings of linking word roots were highly heterogeneous; over half of reviewers rated "association" as having at least some causal implication. This research undercuts the assumption that avoiding "causal" words leads to clarity of interpretation in medical research.Marie Skłodowska-Curie grantAustralian Research CouncilNational Institute of Mental HealthNational Institute of Mental HealthNational Institute of Biomedical Imaging and BioengineeringNational Center for Advancing Translational Sciences UCLA Clinical Translational Science InstituteBloomberg American Health InitiativeKaren Toffler Charity Trus