Spectroscopic techniques and the conservation of artists’ acrylic emulsion paints

Artists’ acrylic emulsion paints are used in many contexts such as paintings, murals, sculptures, works on paper and mixed media; and are forming increasing proportions of modern and contemporary art collections. Although acrylic emulsion paints have been the focus of museum-led research over the past decade, the impact of artists’ technique and conservation treatment on the upper-most surface of these paints remains essentially unexplored ; This paper summarises previous studies using vibrational (FTIR) spectroscopy and presents initial assessments of paint surfaces using X-ray spectroscopies (XPS and NEXAFS) aimed at characterising artists’ acrylic paint film surfaces after natural ageing and wet surface cleaning treatment. Both techniques were found to be well suited for surface-sensitive investigations of the organic materials associated with artists’ acrylic paints, including explorations into: (A) cleaning system residues, (B) surfactant extraction from paint surfaces, (C) the identification of migrated surfactant, and (D) monitoring pigment changes at the paint/air interface of paint films ; It has been shown is that these X-ray spectroscopic techniques can be used for the analysis of almost purely organic materials in a way that complements mass spectroscopic techniques, FTIR and XRF. This investigation forms part of broader, currently ongoing, multi-technique investigation into the properties of artists’ acrylic paints and development of conservation treatments for works-of-art made with these materials

Diffusion of water from a range of conservation treatment gels into paint films studied by unilateral NMR: Part I: Acrylic emulsion paint

Unilateral NMR was used to monitor the penetration of water into acrylic emulsion paint-outs on canvas during cleaning simulations with five thickened conservation treatment systems – agarose gels, methylcellulose paste, Pemulen-TR2, poly(vinyl alcohol)-borax gels, and Velvesil Plus – and water-moistened swabs. Studies were also carried out to measure the rate of water penetration from the different treatment methods into acrylic paints during continuous exposure. Unilateral NMR is shown to be an effective technique for comparing depth penetration of water during cleaning treatments; the volume of paint occupied by water can be extracted from these measurements. The results show that young paint films (1 month) are more prone to swelling than aged paint films (2–50 years), with light aged paints having the highest resistance to water penetration during treatments. Aged organic pigmented acrylic paint (Hansa yellow light) shows a higher propensity for swelling during cleaning than aged titanium dioxide white paint. Cleaning simulations using water-moistened swabs and agar gels deposit approximately equivalent amounts of water into the paint films, whilst all other gel systems tested, with the exception of Velvesil Plus, tend to allow approximately 50% more water into the paint films. None of the aqueous thickened cleaning systems tested reduced the quantity of water which entered the paint films relative to swab cleaning

Palatal Actinomycosis and Kaposi Sarcoma in an HIV-Infected Subject with Disseminated Mycobacterium avium-intracellulare Infection

Actinomyces and Mycobacterium avium-intracellulare are facultative intracellular organisms, members of the bacterial order actinomycetales. Although Actinomyces can behave as copathogen when anatomic barriers are compromised, its coinfection with Mycobacterium avium-intracellulare has not previously been reported. We present the first reported case of palatal actinomycosis co-infection with disseminated MAC, in an HIV-infected subject with Kaposi sarcoma and diabetes. We discuss the pathogenesis of the complex condition of this subject

Patient Perspectives on Acquiring Spectacles: A Cambodian Experience

Purpose: To assess the perspectives of patients who acquired spectacles from an eye unit/vision center in Cambodia. Design: A sample (n = 62) of patients was selected across 4 provinces: Prey Veng, Siem Reap, Battambang, and Takeo. Methods: The Patient Spectacle Satisfaction Survey covering demographic and semistructured questions regarding patient satisfaction, style, and costs incurred was used to collect data. Information was transcribed and translated into English and analyzed by thematic coding using NVivo. Results: Although there were more women seeking eye health care treatment, there was no significant age difference. Patient satisfaction levels were high although the patients had to pay for transportation, registration, and the glasses themselves. A total of 60 patients (96.7%) stated they would recommend the refractive service center to others. Despite a high level of awareness of eye disease such as cataract, only 2 in 10 people could accurately identify cataract as a major cause of poor vision or blindness. Most of the people (52%) blamed bad vision or blindness on dust or other foreign objects getting into the eye, old age (31%), or poor hygiene (16%). Conclusions: Most people will pay eye care costs once barriers to seeking treatment have been broken via education and encouragement. Satisfaction of wearing spectacles was associated with improved vision; style, color, and fit of the spectacles; and protection from sunlight and dust. The proximity of and easy access to health facilities influenced patient desire to seek treatment

MODIS-HIRIS ground data systems commonality report

The High Resolution Imaging Spectrometer (HIRIS) and Moderate Resolution Imaging Spectrometer (MODIS) Data Systems Working Group was formed in September 1988 with representatives of the MODIS Data System Study Group and the HIRIS Project Data System Design Group to collaborate in the development of requirements on the EosDIS necessary to meet the science objectives of the two facility instruments. A major objective was to identify and promote commonality between the HIRIS and MODIS data systems, especially from the science users' point of view. A goal was to provide a base set of joint requirements and specifications which could easily be expanded to a Phase-B representation of the needs of the science users of all EOS instruments. This document describes the points of commonality and difference between the Level-II Requirements, Operations Concepts, and Systems Specifications for the ground data systems for the MODIS and HIRIS instruments at their present state of development

Barriers to the Uptake of Cataract Surgery and Eye Care After Community Outreach Screening in Takeo Province, Cambodia

Purpose: To assess the barriers influencing eye healthcare seeking be-havior after community outreach screening. Design: A concurrent mixed methods study. Methods: A total of 469 patients screened during the previous 12 months were followed up, of which 354 (75%) from 5 districts were in-terviewed in person, using a semi-structured questionnaire, in-depth in-terviews (n = 11), and 16 focus groups (n = 71). SPSS and NVivo were used to analyze response frequency and identify themes. Results: Of the respondents, 98% (350/354) reported they were told they had an eye problem, with 295 individuals (83%) told to attend CARITAS Takeo Eye Hospital (CTEH) and 55 to have their eyes checked at Kiri Vong Vision Centre. Of those 68.9% (244/354) who reported seeking treatment, only 7.4% (18/244) reported they attended CTEH, 54% (n = 132) attended a “local pharmacy,” 31.6% (n = 77) “self-treated at home,” 11% (n = 27) reported “using steam from boiling rice,” and 10.7% (n = 26) attended a “traditional healer.” Of those who reported reasons for “not attending,” responses included “no time” (47.8%, 86/180), “no one to accompany” (21.7%, n = 39), “fear of losing sight” (17.8%, n = 32), “cannot afford to travel” (16.1%, n = 29), and “eye problem is not serious enough” (15.6%, n = 28). Follow-up of patient records identified that 128 individuals (79 females) attended eye care services. Conclusions: Socioeconomic factors, personal concerns, and the use of local cultural remedies were reasons for not seeking eye hospital treatment. An integrated community approach to improve awareness and uptake of appropriate treatment is recommended

APOBEC3G mRNA expression in exposed seronegative and early stage HIV infected individuals decreases with removal of exposure and with disease progression

<p>Abstract</p> <p>Background</p> <p>APOBEC3G is an antiretroviral factor that acts by inducing G to A mutations. In this study, we examined the expression of APOBEC3G in uninfected HIV-1 exposed individuals at the time of their partner's diagnosis and one year later. We then compared this expression with that of infected individuals at different disease stages. APOBEC3G mRNA was measured in PBMCs from three groups: healthy controls with no known risk factor to HIV infection (n = 26), exposed uninfected individuals who had unprotected sex with their HIV+ partners for at least 3 months (n = 37), and HIV infected patients at various disease stages (n = 45), including 8 patients with low HIV viral loads < 10,000 copies/mL (LVL) for at least 3 years. Additionally, we obtained sequences from the env, gag, pol, nef, vif and the LTR of the patients' virus.</p> <p>Results</p> <p>Exposed uninfected individuals expressed higher APOBEC3G than healthy controls (3.86 vs. 1.69 relative expression units), and their expression significantly decreased after a year from the HIV diagnosis and subsequent treatment of their partners. Infected individuals showed a positive correlation (Rho = 0.57, p = 0.00006) of APOBEC3G expression with CD4+ T cell count, and a negative correlation with HIV viremia (Rho = -0.54, p = 0.00004). The percentage of G to A mutations had a positive correlation (Rho = 0.43, p = 0.0226) with APOBEC3G expression, and it was higher in LVL individuals than in the other patients (IQR 8.27 to 9.64 vs. 7.06 to 8.1, p = 0.0084). Out of 8 LVLs, 3 had hypermutations, and 4 had premature stop codons only in viral <it>vif</it>.</p> <p>Conclusion</p> <p>The results suggest that exposure to HIV may trigger APOBEC3G expression in PBMCs, in the absence of infection. Additionally, cessation of exposure or advanced disease is associated with decreased APOBEC3G expression.</p

A single whole-body low dose X-irradiation does not affect L1, B1 and IAP repeat element DNA methylation longitudinally

The low dose radioadaptive response has been shown to be protective against high doses of radiation as well as aging-induced genomic instability. We hypothesised that a single whole-body exposure of low dose radiation would induce a radioadaptive response thereby reducing or abrogating aging-related changes in repeat element DNA methylation in mice. Following sham or 10 mGy X-irradiation, serial peripheral blood sampling was performed and differences in Long Interspersed Nucleic Element 1 (L1), B1 and Intracisternal-A-Particle (IAP) repeat element methylation between samples were assessed using high resolution melt analysis of PCR amplicons. By 420 days post-irradiation, neither radiation- or aging-related changes in the methylation of peripheral blood, spleen or liver L1, B1 and IAP elements were observed. Analysis of the spleen and liver tissues of cohorts of untreated aging mice showed that the 17-19 month age group exhibited higher repeat element methylation than younger or older mice, with no overall decline in methylation detected with age. This is the first temporal analysis of the effect of low dose radiation on repeat element methylation in mouse peripheral blood and the first to examine the long term effect of this dose on repeat element methylation in a radiosensitive tissue (spleen) and a tissue fundamental to the aging process (liver). Our data indicate that the methylation of murine DNA repeat elements can fluctuate with age, but unlike human studies, do not demonstrate an overall aging-related decline. Furthermore, our results indicate that a low dose of ionising radiation does not induce detectable changes to murine repeat element DNA methylation in the tissues and at the time-points examined in this study. This radiation dose is relevant to human diagnostic radiation exposures and suggests that a dose of 10 mGy X-rays, unlike high dose radiation, does not cause significant short or long term changes to repeat element or global DNA methylation.Michelle R. Newman, Pamela J. Sykes, Benjamin J. Blyth, Eva Bezak, Mark D. Lawrence, Katherine L. Morel, Rebecca J. Ormsb