481 research outputs found
Effect of traditional beer consumption on the iron status of a rural South African population
Objective. To determine the effect of traditional beer consumption on the iron status of rural black subjects.
Design. A cross-sectional study was undertaken.
Setting. Dikgale field site and the surrounding villages in Limpopo Province, South Africa.
Subjects. Eight hundred and forty-four non-alcohol consumers (738 women and 106 men) and 280 alcohol consumers (163 women and 117 men) aged 30 years and above, participated in the study.
Outcome measures. Outcome measures included alcohol consumption, serum ferritin levels, percentage transferrin saturation, total iron-binding capacity, haemoglobin and C-reactive protein levels.
Results. Traditional beer fermented in either iron pots or plastic containers was found to have iron levels ranging from 15 mg/l to 67.8 mg/l and 6 mg/l to 17 mg/l, respectively. Iron status as measured by serum ferritin, serum iron, percentage transferrin saturation, and haemoglobin levels was significantly higher in alcohol consumers than in non-consumers, even after adjustment for age and C-reactive protein (CRP) levels. A
high percentage of women (12.3%) and men (8.2%) consuming alcohol had iron overload.
Conclusion. This study showed that consumption of traditional beer in a non-urban population in Limpopo Province was associated with high levels of markers of iron status. Traditional beer consumption seemed to prevent iron deficiency in those at risk of developing such deficiency, but appeared to precipitate iron overload
in those at risk of developing iron overload.South African Journal Clinical Nutrition Vol. 20 (2) 2007: pp. 62-6
Bioassay-guided isolation and identification of antimicrobial compounds from thyme essential oil by means of overpressured layer chromatography, bioautography and GC-MS
A simple method is described for efficient isolation of compounds having an antibacterial effect.
Two thyme (Thymus vulgaris) essential oils, obtained from the market, were chosen as
prospective materials likely to feature several bioactive components when examined by thin layer
chromatography coupled with direct bioautography as a screening method. The newly developed
infusion overpressured layer chromatographic separation method coupled with direct
bioautography assured that only the active components were isolated by means of overrun
overpressured layer chromatography with online detection and fractionation. Each of the 5
collected fractions represented one of the five antimicrobial essential oil components designated
at the screening. The purity and the activity of the fractions were confirmed with chromatography
coupled various detection methods (UV, vanillin-sulphuric acid reagent, direct bioautography).
The antibacterial components were identified with GC-MS as thymol, carvacrol, linalool, diethylphthalate,
and alpha-terpineol. The oil component diethyl-phthalate is an artificial compound,
used as plasticizer or detergent bases in the industry. Our results support that exploiting its
flexibility and the possible hyphenations, overpressured layer chromatography is especially
attractive for isolation of antimicrobial components from various matrixes
Detection of antibacterial activity of essential oil components by TLC-bioautography using luminescent bacteria
The aim of the present study was the chemical characterization of some medically relevant essential oils (tea tree, clove, cinnamon bark, thyme and eucalyptus) and the investigation of antibacterial effect of the components of these oils by use of a direct bioautographic method. Thin layer chromatography (TLC) was combined with biological detection in this process. The chemical composition of the oils was determined by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Eucalyptol (84.2%) was the main component of the essential oil of eucalyptus, eugenol (83.7%) of clove oil, and trans-cinnamic aldehyde (73.2%), thymol (49.9%) and terpinen-4-ol (45.8%) of cinnamon bark, thyme and tea tree oils, respectively. Antibacterial activity of the separated components of these oils, as well as their pure main components (eucalyptol, eugenol, trans-cinnamic aldehyde and thymol) was observed against the Gram-negative luminescence tagged plant pathogenic bacterium Pseudomonas syringae pv. maculicola (Psmlux) and the Gram-negative, naturally luminescent marine bacterium Vibrio fischeri. On the whole, the antibacterial activity of the essential oils could be related to their main components, but the minor constituents may be involved in this process. Trans-cinnamic aldehyde and eugenol were the most active compounds in TLC-bioautography.
The sensitivity of TLC-bioautographic method can be improved with using luminescent test bacteria. This method is more cost-effective and provides more reliable results in comparison with conventional microbiological methods, e.g. disc-diffusion technique
Ultra-high resolution Fourier domain optical coherence tomography for old master paintings
In the last 10 years, Optical Coherence Tomography (OCT) has been successfully applied to art conservation, history and archaeology. OCT has the potential to become a routine non-invasive tool in museums allowing cross-section imaging anywhere on an intact object where there are no other methods of obtaining subsurface information. While current commercial OCTs have shown potential in this field, they are still limited in depth resolution (> 4 ÎŒm in paint and varnish) compared to conventional microscopic examination of sampled paint cross-sections (~1 ÎŒm). An ultrahigh resolution fiber-based Fourier domain optical coherence tomography system with a constant axial resolution of 1.2 ÎŒm in varnish or paint throughout a depth range of 1.5 mm has been developed. While Fourier domain OCT of similar resolution has been demonstrated recently, the sensitivity roll-off of some of these systems are still significant. In contrast, this current system achieved a sensitivity roll-off that is less than 2 dB over a 1.2 mm depth range with an incident power of ~1 mW on the sample. The high resolution and sensitivity of the system makes it convenient to image thin varnish and glaze layers with unprecedented contrast. The non-invasive 'virtual' cross-section images obtained with the system show the thin varnish layers with similar resolution in the depth direction but superior clarity in the layer interfaces when compared with conventional optical microscope images of actual paint sample cross-sections obtained microdestructively
Triggered optical coherence tomography for capturing rapid periodic motion
Quantitative cross-sectional imaging of vocal folds during phonation is potentially useful for diagnosis and treatments of laryngeal disorders. Optical coherence tomography (OCT) is a powerful technique, but its relatively low frame rates makes it challenging to visualize rapidly vibrating tissues. Here, we demonstrate a novel method based on triggered laser scanning to capture 4-dimensional (4D) images of samples in motu at audio frequencies over 100â
Hz. As proof-of-concept experiments, we applied this technique to imaging the oscillations of biopolymer gels on acoustic vibrators and aerodynamically driven vibrations of the vocal fold in an ex vivo calf larynx model. Our results suggest that triggered 4D OCT may be useful in understanding and assessing the function of vocal folds and developing novel treatments in research and clinical settings
α-(1 â 3)-d-Glucans from fruiting bodies of selected macromycetes fungi and the biological activity of their carboxymethylated products
Ultrahigh speed 1050nm swept source / Fourier domain OCT retinal and anterior segment imaging at 100,000 to 400,000 axial scans per second
We demonstrate ultrahigh speed swept source/Fourier domain ophthalmic OCT imaging using a short cavity swept laser at 100,000 â 400,000 axial scan rates. Several design configurations illustrate tradeoffs in imaging speed, sensitivity, axial resolution, and imaging depth. Variable rate A/D optical clocking is used to acquire linear-in-k OCT fringe data at 100kHz axial scan rate with 5.3um axial resolution in tissue. Fixed rate sampling at 1 GSPS achieves a 7.5mm imaging range in tissue with 6.0um axial resolution at 100kHz axial scan rate. A 200kHz axial scan rate with 5.3um axial resolution over 4mm imaging range is achieved by buffering the laser sweep. Dual spot OCT using two parallel interferometers achieves 400kHz axial scan rate, almost 2X faster than previous 1050nm ophthalmic results and 20X faster than current commercial instruments. Superior sensitivity roll-off performance is shown. Imaging is demonstrated in the human retina and anterior segment. Wide field 12Ă12mm data sets include the macula and optic nerve head. Small area, high density imaging shows individual cone photoreceptors. The 7.5mm imaging range configuration can show the cornea, iris, and anterior lens in a single image. These improvements in imaging speed and depth range provide important advantages for ophthalmic imaging. The ability to rapidly acquire 3D-OCT data over a wide field of view promises to simplify examination protocols. The ability to image fine structures can provide detailed information on focal pathologies. The large imaging range and improved image penetration at 1050nm wavelengths promises to improve performance for instrumentation which images both the retina and anterior eye. These advantages suggest that swept source OCT at 1050nm wavelengths will play an important role in future ophthalmic instrumentation.National Institutes of Health (U.S.) (5R01-EY011289-23)National Institutes of Health (U.S.) (5R01-EY013178-10)National Institutes of Health (U.S.) (2R01-EY013516-07)National Institutes of Health (U.S.) (1R01-EY019029-02)United States. Air Force Office of Scientific Research (Contract Number FA9550-07-1-0014)United States. Dept. of Defense. Medical Free Electron Laser Program (Contract Number FA9550-07-1-0101
The person-based nature of prejudice: Individual difference predictors of intergroup negativity
Person-based factors influence a range of meaningful life outcomes, including intergroup processes, and have long been implicated in explaining prejudice. In addition to demonstrating significant heritability, person-based factors are evident in expressions of generalised prejudice, a robust finding that some people (relative to others) consistently score higher in prejudice towards multiple outgroups. Our contemporary review includes personality factors, ideological orientations (e.g., authoritarianism), religiosity, anxiety, threat, disgust sensitivity, and cognitive abilities and styles. Meta-analytic syntheses demonstrate that such constructs consistently predict prejudice, often at the upper bounds of effect sizes observed in psychological research. We conclude that prejudice theories need to better integrate person- and situation-based factors, including their interaction, to capture the complexity of prejudice and inform intervention development
Chronic recurrent Gorham-Stout syndrome with cutaneous involvement
Type IV osteolysis or Gorham-Stout syndrome is a rare condition characterized by recurrent vascular tumors that disrupt normal anatomical architecture. Gorham-Stout syndrome is most commonly associated with the skeletal system with resulting replacement of bone with scar tissue following tumor regression. The loss of entire bones has given Gorham-Stout syndrome the moniker vanishing bone disease. Natural progression of Gorham-Stout syndrome is characterized by spontaneous disease resolution. However, rare variants of recurrent, progressive, and/or systemic disease have been reported. We present a patient with a history of recurrent Gorham- Stout disease refractory to all treatment options considered. In addition to skeletal disease, our patient had soft tissue and cutaneous involvement, thus reflecting the more aggressive disease variant. Previous surgical attempts to control disease had been ineffective and the patient was referred to us for radiation therapy. Treatment with external beam radiation therapy resulted in good local control and symptom palliation, but full disease resolution was never accomplished. In addition to presentation of this patient, a review of the literature on etiological hypotheses and past/future treatment options was conducted and is included
An exploration and proposed taxonomy of leisureâbefriending for adults with learning disabilities
© 2019 The Authors. British Journal of Learning Disabilities Published by John Wiley & Sons Ltd Taking part in leisure activities is beneficial, yet many adults with learning disabilities are unable to participate in their preferred activities because of cost, because not having anyone to go with or because they do not feel welcome. Befriending is where someone volunteers to act as a friend. Befriending may be a way for adults with learning disabilities to participate in leisure activities with someone who is not a paid carer or family. The author spent time with four people with learning disabilities and their befrienders to find out what things they do together and what they both get from it. Friends and family members were also interviewed. Participants enjoyed the time they spent together. However, they often did the same activities they would do with paid carers or family and the relationship was sometimes quite professional. Befriending could be a way for adults with learning disabilities to have new, beneficial experiences, but we need to know more about how relationships work. Abstract: Background Leisure time for adults with learning disabilities is often diversionary and spent doing passive, solitary or family-orientated activities. Befriending, as a hybrid ânaturalâ support, may help adults with learning disabilities overcome the barriers to participation in nonsegregated leisure. Materials and methods Four case studies of pairs of âbefriendersâ and âbefriendeesâ were recruited purposively. Participant observation was carried out with each case, followed by semi-structured interviews with participants and relevant stakeholders. Data were analysed using thematic analysis. Results Befriending activities were mostly limited to enjoyable yet âcasualâ leisure activities that adults with learning disabilities might already participate in with family and paid service providers. Negotiating the befriender role between friend and professional was an ongoing challenge. Conclusions Outcomes of leisureâbefriending relationships for adults with learning disabilities are linked to both the nature of relationships and the types of activities undertaken. There are four proposed ideal types of leisureâbefriending relationship, yet repeating familiar âcasualâ leisure activities means adults with learning disabilities risk missing out on novel leisure and social experiences
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