599 research outputs found
Carn Goedog medieval house and settlement, Pembrokeshire
This report describes the investigation in 2011 and 2015 of two groups of relict houses on an upland
common on the north flank of the Preseli hills in North Pembrokeshire. Their locations, along with
medieval records, provide strong indications that these were seasonal settlements. Excavation of one subrectangular building (House C) produced finds that included medieval pottery and a spindle whorl with
Romanesque decoration. A radiocarbon date of cal. AD 1030–1200 at 95.4% confidence from charcoal
in the hearth of this building provides the earliest firm date identified as yet for hafodydd (‘seasonal
settlements’) in Wale
Evidence of re-osseointegration after electrolytic cleaning and regenerative therapy of peri-implantitis in humans: a case report with four implants.
OBJECTIVE
To evaluate re-osseointegration after electrolytic cleaning and regenerative therapy of dental implants with peri-implantitis in humans.
MATERIAL AND METHODS
Four dental implants that developed peri-implantitis underwent electrolytic cleaning followed by regenerative therapy with guided bone regeneration. All four implants developed recurrent peri-implantitis and were therefore explanted 6 to 13 months later. Radiographic bone level, probing depth, and bleeding on probing were determined at the time of surgery, 6 months later, and before implant retrieval. The peri-implant tissues were histologically and histomorphometrically analyzed.
RESULTS
All four implants demonstrated radiographic and histological bone gain, reduced probing depth, and bleeding on probing. Radiographic bone gain was 5.8 mm mesially and 4.8 mm distally for implant #1, 3.3 mm and 2.3 mm for implant #2, 3.1 mm and 0.5 mm for implant #3, and 3.5 mm and 2.8 mm for implant #4. The histometric mean and maximum vertical bone gain for implant #1 to #4 was 1.65 mm and 2.54 mm, 3.04 mm and 3.47 mm, 0.43 mm and 1.27 mm, and 4.16 mm and 5.22 mm, respectively. The percentage of re-osseointegration for implant #1 to #4 was 21.0%, 36.9%, 5.7%, and 39.0%, respectively. In one implant, the newly formed bone was deposited directly onto calculus on the implant surface.
CONCLUSIONS
We found that (1) re-osseointegration is possible on a formerly contaminated implant surface and (2) the electrolytic cleaning process seems to be effective enough at sites with calculus residues.
CLINICAL RELEVANCE
Since re-osseointegration can be achieved by electrolytic cleaning, this decontamination technique may be considered as a future treatment concept
High-Density Lignin-Derived Carbon Nanofiber Supercapacitors with Enhanced Volumetric Energy Density
Supercapacitors are increasingly used in short-distance electric transportation due to their long lifetime (≈15 years) and fast charging capability (>10 A g^{−1}). To improve their market penetration, while minimizing onboard weight and maximizing space-efficiency, materials costs must be reduced (8 Wh L^{−1}). Carbon nanofibers display good gravimetric capacitance, yet their marketability is hindered by their low density (0.05–0.1 g cm^{−3}). Here, the authors increase the packing density of low-cost, free-standing carbon nanofiber mats (from 0.1 to 0.6 g cm−3) through uniaxial compression. X-ray computed tomography reveals that densification occurs by reducing the inter-fiber pore size (from 1–5 µm to 0.2–0.5 µm), which are not involved in double-layer capacitance. The improved packing density is directly proportional to the volumetric performances of the device, which reaches a volumetric capacitance of 130 F cm^{−3} and energy density of 6 Wh L^{−1} at 0.1 A g^{−1} using a loading of 3 mg cm^{−2}. The results outperform most commercial and lab-scale porous carbons synthesized from bioresources (50–100 F cm^{−3}, 1–3 Wh L^{−1} using 10 mg cm^{−2}) and contribute to the scalable design of sustainable electrodes with minimal ‘dead volume’ for efficient supercapacitors
Megalith quarries for Stonehenge’s bluestones. Review
Geologists and archaeologists have long known that the bluestones of Stonehenge came from the Preseli Hills of west Wales, 230km away, but only recently have some of their exact geological sources been identified. Two of these quarries - Carn Goedog and Craig Rhos-y-felin - have now been excavated to reveal evidence of megalith quarrying around 3000 BC - the same period as the first stage of the construction of Stonehenge. The authors present evidence for the extraction of the stone pillars and consider how they were transported, including the possibility that they were erected in a temporary monument close to the quarries, before completing their journey to Stonehenge
Effect of yoghurt containing Bifidobacterium lactis Bb12® on faecal excretion of secretory immunoglobulin A and human beta-defensin 2 in healthy adult volunteers
<p>Abstract</p> <p>Background</p> <p>Probiotics are used to provide health benefits. The present study tested the effect of a probiotic yoghurt on faecal output of beta-defensin and immunoglobulin A in a group of young healthy women eating a defined diet.</p> <p>Findings</p> <p>26 women aged 18-21 (median 19) years residing in a hostel were given 200 ml normal yoghurt every day for a week, followed by probiotic yoghurt containing <it>Bifidobacterium lactis </it>Bb12<sup>® </sup>(10<sup>9 </sup>in 200 ml) for three weeks, followed again by normal yoghurt for four weeks. Stool samples were collected at 0, 4 and 8 weeks and assayed for immunoglobulin A and human beta-defensin-2 by ELISA. All participants tolerated both normal and probiotic yoghurt well. Human beta-defensin-2 levels in faeces were not altered during the course of the study. On the other hand, compared to the basal sample, faecal IgA increased during probiotic feeding (P = 0.0184) and returned to normal after cessation of probiotic yoghurt intake.</p> <p>Conclusions</p> <p><it>Bifidobacterium lactis </it>Bb12<sup>® </sup>increased secretory IgA output in faeces. This property may explain the ability of probiotics to prevent gastrointestinal and lower respiratory tract infections.</p
Emprego da biofumigação do solo com torta de mamona no controle do nematoide das galhas (Meloidogyne javanica) e na produção e qualidade de alface 'Elisa'.
Craig Rhos-y-felin: A Welsh bluestone megalith quarry for Stonehenge
The long-distance transport of the bluestones from south Wales to Stonehenge is one of the most remarkable achievements of Neolithic societies in north-west Europe. Where precisely these stones were quarried, when they were extracted and how they were transported has long been a subject of speculation, experiment and controversy. The discovery of a megalithic bluestone quarry at Craig Rhos-y-felin in 2011 marked a turning point in this research. Subsequent excavations have provided details of the quarrying process along with direct dating evidence for the extraction of bluestone monoliths at this location, demonstrating both Neolithic and Early Bronze Age activity
Tinnitus prevalence in Europe: a multi-country cross-sectional population study
BackgroundTinnitus prevalence studies report large variability across countries that might be due to inconsistent research methods. Our study aimed to report a single Pan-European estimate for tinnitus prevalence and investigate the effect of individual and country-level characteristics on prevalence. We explored the relationships of healthcare resource use and hearing difficulty with tinnitus symptoms.MethodsBetween 2017-2018, a cross-sectional European Tinnitus Survey (ETS) was conducted in 12 European Union nations (Bulgaria, England, France, Germany, Greece, Ireland, Italy, Latvia, Poland, Portugal, Romania, and Spain), using a standardised set of tinnitus-related questions and response options in country-specific languages. We recruited 11,427 adults aged ≥18 years.FindingsPrevalence of any tinnitus was 14·7% (14·0% in men and 15·2% in women), ranging from 8·7% in Ireland to 28·3% in Bulgaria. Severe tinnitus was found in 1·2% participants (1·0% in men and 1·4% in women), ranging from 0·6% in Ireland to 4·2% in Romania. Tinnitus prevalence significantly increased with increasing age and worsening of hearing status. Healthcare resource use for tinnitus increased with increasing tinnitus symptom severity.InterpretationThis is the first multinational report of Pan-European tinnitus prevalence using standardised questions. The overall prevalence estimates refine previous findings, although widespread inter-country heterogeneity was noted. The results indicate that more than 1 in 7 adults in the EU have tinnitus. Extrapolating to the overall population, approximately 65 million adults in EU28 have tinnitus, 26 million have bothersome tinnitus and 4 million have severe tinnitus.FundingNational Institute for Health Research, European Union's Horizon 2020, Medical Research Council, and GENDER-Net Co-Plus Fund
Piezoelectric osteotomy in hand surgery: first experiences with a new technique
BACKGROUND: In hand and spinal surgery nerve lesions are feared complications with the use of standard oscillating saws. Oral surgeons have started using a newly developed ultrasound bone scalpel when performing precise osteotomies. By using a frequency of 25–29 kHz only mineralized tissue is cut, sparing the soft tissue. This reduces the risk of nerve lesions. As there is a lack of experience with this technique in the field of orthopaedic bone surgery, we performed the first ultrasound osteotomy in hand surgery. METHOD: While performing a correctional osteotomy of the 5th metacarpal bone we used the Piezosurgery(® )Device from Mectron [Italy] instead of the usual oscillating saw. We will report on our experience with one case, with a follow up time of one year. RESULTS: The cut was highly precise and there were no vibrations of the bone. The time needed for the operation was slightly longer than the time needed while using the usual saw. Bone healing was good and at no point were there any neurovascular disturbances. CONCLUSION: The Piezosurgery(® )Device is useful for small long bone osteotomies. Using the fine tip enables curved cutting and provides an opportunity for new osteotomy techniques. As the device selectively cuts bone we feel that this device has great potential in the field of hand- and spinal surgery
Equilibrium model selection: dTTP induced R1 dimerization
<p>Abstract</p> <p>Background</p> <p>Biochemical equilibria are usually modeled iteratively: given one or a few fitted models, if there is a lack of fit or over fitting, a new model with additional or fewer parameters is then fitted, and the process is repeated. The problem with this approach is that different analysts can propose and select different models and thus extract different binding parameter estimates from the same data. An alternative is to first generate a comprehensive standardized list of plausible models, and to then fit them exhaustively, or semi-exhaustively.</p> <p>Results</p> <p>A framework is presented in which equilibriums are modeled as pairs (<it>g</it>, <it>h</it>) where <it>g </it>= 0 maps total reactant concentrations (system inputs) into free reactant concentrations (system states) which <it>h </it>then maps into expected values of measurements (system outputs). By letting dissociation constants <it>K</it><sub><it>d </it></sub>be either freely estimated, infinity, zero, or equal to other <it>K</it><sub><it>d</it></sub>, and by letting undamaged protein fractions be either freely estimated or 1, many <it>g </it>models are formed. A standard space of <it>g </it>models for ligand-induced protein dimerization equilibria is given. Coupled to an <it>h </it>model, the resulting (<it>g</it>, <it>h</it>) were fitted to dTTP induced R1 dimerization data (R1 is the large subunit of ribonucleotide reductase). Models with the fewest parameters were fitted first. Thereafter, upon fitting a batch, the next batch of models (with one more parameter) was fitted only if the current batch yielded a model that was better (based on the Akaike Information Criterion) than the best model in the previous batch (with one less parameter). Within batches models were fitted in parallel. This semi-exhaustive approach yielded the same best models as an exhaustive model space fit, but in approximately one-fifth the time.</p> <p>Conclusion</p> <p>Comprehensive model space based biochemical equilibrium model selection methods are realizable. Their significance to systems biology as mappings of data into mathematical models warrants their development.</p
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