453 research outputs found

    Glaciological results of the 2005 expedition to Inylchek Glacier, Central Tian Shan

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    Like many other glaciers in Central Asia, Southern Inylchek glacier in the Kyrgyz Tian Shan is covered by supraglacial moraine, which drastically influences melt rates and complicates the estimation of ablation. The quantification of sub-debris melt from simple parameters is still an unsolved problem, but also essential to predict future yield from high mountains. Snow cover and glacier ice are the main water storages for the surrounding arid lowlands and a better understanding of ablation processes is the prerequisite for a sustainable water resources management. Another interesting feature of Southern Inylchek glacier is the existence of an ice dammed lake in a tributary valley, which is drained regularly by outburst floods. Improvements in predicting these floods would lower the risk potential for the downstream population. The main objectives of a group of glaciologists which participated in an expedition to the glacier in 2005 were to investigate melt rates on debris covered glacier parts and to quantify the ice flux into the glacier lake. The results of their field experiments are reported in this paper

    Lipid rescue of massive verapamil overdose: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Massive intentional verapamil overdose is a toxic ingestion which can cause multiorgan system failure and has no currently known antidote.</p> <p>Case Presentation</p> <p>The patient is a 41-year-old Caucasian woman who ingested 19.2 g of sustained release verapamil in a suicide attempt. Our patient became hypotensive requiring three high-dose vasopressors to maintain arterial pressure. She also developed acute respiratory failure, bradycardic ventricular rhythm necessitating continuous transvenous pacing, and anuric renal failure. Our patient was treated with intravenous calcium, bicarbonate, hyperinsulinemic euglycemic therapy and continuous venovenous hemodialysis without success. On the fourth day after hospital admission continuous intravenous lipid therapy was initiated. Within three hours of beginning lipid therapy, our patient's vasopressor requirement decreased by half. Within 24 hours, she was on minimal vasopressor support and regained an underlying junctional rhythm. After three days of lipid infusion, she no longer required inotropic agents to maintain blood pressure or pacing to maintain stable hemodynamics.</p> <p>Conclusions</p> <p>Intravenous fat emulsion therapy may be an effective antidote for massive verapamil toxicity.</p

    Glaciological results of the 2005 expedition to Inylchek Glacier, Central Tian Shan

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    Like many other glaciers in Central Asia, Southern Inylchek glacier in the Kyrgyz Tian Shan is covered by supraglacial moraine, which drastically influences melt rates and complicates the estimation of ablation. The quantification of sub-debris melt from simple parameters is still an unsolved problem, but also essential to predict future yield from high mountains. Snow cover and glacier ice are the main water storages for the surrounding arid lowlands and a better understanding of ablation processes is the prerequisite for a sustainable water resources management. Another interesting feature of Southern Inylchek glacier is the existence of an ice dammed lake in a tributary valley, which is drained regularly by outburst floods. Improvements in predicting these floods would lower the risk potential for the downstream population. The main objectives of a group of glaciologists which participated in an expedition to the glacier in 2005 were to investigate melt rates on debris covered glacier parts and to quantify the ice flux into the glacier lake. The results of their field experiments are reported in this paper

    New standards for permanent tooth emergence in Australian children

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    The document attached has been archived with permission from the Australian Dental Association. An external link to the publisher’s copy is included.Background: Published standards for permanent tooth emergence in Australian children are 40 years old. The aim of this study was to present new data on the timing and sequence of permanent tooth emergence in a large sample of Australian children and to compare the findings with those of earlier studies. Methods: Records of a randomly selected sample of 8676 children, aged between 4 to 16 years, who had attended the clinics of the South Australian Dental Service were scanned optically and coded to provide the data for this study. A logistic regression analysis enabled median times of emergence, together with percentile ranges, to be calculated for each tooth, except third molars, in boys and girls. Comparisons were made between the sexes and with previously published values. The frequencies of occurrence of emergence polymorphisms for different tooth pairs were also computed. Results: The earliest teeth to emerge in both boys and girls were the central incisors and first molars, whereas the second premolars and molars and maxillary canines tended to be last to emerge. The mandibular teeth tended to precede the corresponding maxillary teeth in emergence in both sexes. Tooth emergence was advanced in girls compared with boys, averaging 4.5 months in the maxilla and 5.3 months in the mandible. In general, emergence times of children in the present sample were later than those reported previously for Australian children. The most common emergence polymorphism in the maxilla involved the canine and second premolar, whereas common polymorphisms in the mandible were noted for the central incisor and first molar, canine and first premolar, and the second premolar and second molar. Conclusions: Given that they have been collected relatively recently from a large sample of children, the new data reported in this paper can now be used as standards when assessing permanent tooth emergence of Australian children.J Diamanti, GC Townsen

    Ultrastructural study of plaque biofilms in an Invisalign orthodontic appliance

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    Hydroxyapatite based hybrid dental materials with controlled porosity and improved tribological and mechanical properties

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    Hybrid dental materials were designed with controlled porosity and improved tribological and mechanical properties. These materials are based on hydroxyapatite (HAp) and reinforced with two different types of ceramic particles, alumina and silica, to support the high stresses and the continuous scratching produced during mastication. The agglutinant phase is an alkyd polyester polyurethane with high abrasion resistance that adheres well to surfaces containing OH groups. Porosity of the materials was controlled using sodium acetate powder of specified particle size as a pore former, thereby providing the materials with a morphology that resembles real teeth. The composition, structure and morphology were evaluated through several analytical techniques; results of scanning electron microscopy, dynamic light scattering, Fourier transform infrared spectroscopy, X-ray diffraction, induced coupled plasma optical emission spectroscopy and densitometry are reported. The ceramic powders incorporated (HAp, alumina and silica) were a combination of micro-and nanoscale particles; this use of different sized particles improved the packing and consequently the mechanical and tribological properties of the dental materials. Tribological features are explained from results of microscratch testing and abrasion resistance. The elastic modulus from mechanical testing is compared for the entire set of hybrid dental composites developed

    Re-establishing glacier monitoring in Kyrgyzstan and Uzbekistan, Central Asia

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    Glacier mass loss is among the clearest indicators of atmospheric warming. The observation of these changes is one of the major objectives of the international climate monitoring strategy developed by the Global Climate Observing System (GCOS). Long-term glacier mass balance measurements are furthermore the basis for calibrating and validating models simulating future runoff of glacierised catchments. This is essential for Central Asia, which is one of the driest continental regions of the Northern Hemisphere. In the highly populated regions, water shortage due to decreased glacierisation potentially leads to pronounced political instability, drastic ecological changes and endangered food security. As a consequence of the collapse of the former Soviet Union, however, many valuable glacier monitoring sites in the Tien Shan and Pamir Mountains were abandoned. In recent years, multinational actors have re-established a set of important in situ measuring sites to continue the invaluable long-term data series. This paper introduces the applied monitoring strategy for selected glaciers in the Kyrgyz and Uzbek Tien Shan and Pamir, highlights the existing and the new measurements on these glaciers, and presents an example for how the old and new data can be combined to establish multi-decadal mass balance time series. This is crucial for understanding the impact of climate change on glaciers in this region

    Vacancy ordering and electronic structure of gamma-Fe2O3 (maghemite): a theoretical investigation

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    The crystal structure of the iron oxide gamma-Fe2O3 is usually reported in either the cubic system (space group P4332) with partial Fe vacancy disorder or in the tetragonal system (space group P41212) with full site ordering and c/a\approx 3. Using a supercell of the cubic structure, we obtain the spectrum of energies of all the ordered configurations which contribute to the partially disordered P4332 cubic structure. Our results show that the configuration with space group P41212 is indeed much more stable than the others, and that this stability arises from a favourable electrostatic contribution, as this configuration exhibits the maximum possible homogeneity in the distribution of iron cations and vacancies. Maghemite is therefore expected to be fully ordered in equilibrium, and deviations from this behaviour should be associated with metastable growth, extended anti-site defects and surface effects in the case of small nanoparticles. The confirmation of the ordered tetragonal structure allows us to investigate the electronic structure of the material using density functional theory (DFT) calculations. The inclusion of a Hubbard (DFT+U) correction allows the calculation of a band gap in good agreement with experiment. The value of the gap is dependent on the electron spin, which is the basis for the spin-filtering properties of maghemite.Comment: 19 pages, 2 tables, 5 figures. To appear in the Journal of Physics - Condensed Matter (2010)

    Clinical significance of stromal apoptosis in colorectal cancer

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    BackgroundEpithelial and stromal cells play an important role in the development of colorectal cancer (CRC). We aimed to determine the prognostic significance of both epithelial and stromal cell apoptosis in CRC.MethodsTotal apoptosis was determined by caspase-3 activity measurements in protein homogenates of CRC specimens and adjacent normal mucosa of 211 CRC patients. Epithelial apoptosis was determined by an ELISA specific for a caspase-3-degraded cytokeratin 18 product, the M30 antigen. Stromal apoptosis was determined from the ratio between total and epithelial apoptosis.ResultsEpithelial and stromal apoptosis, as well as total apoptosis, were significantly higher in CRC compared with corresponding adjacent normal mucosa. Low total tumour apoptosis (&lt; or = median caspase-3 activity) was associated with a significantly worse disease recurrence (hazard ratio (HR), 95% confidence interval (95% CI): 1.77 (1.05-3.01)), independent of clinocopathological parameters. Epithelial apoptosis was not associated with clinical outcome. In contrast, low stromal apoptosis (&lt; or = median caspase-3/M30) was found to be an independent prognostic factor for overall survival, disease-free survival and disease recurrence, with HRs (95% CI) of 1.66 (1.17-2.35), 1.62 (1.15-2.29) and 1.69 (1.01-2.85), respectively.InterpretationStromal apoptosis, in contrast to epithelial apoptosis, is an important factor with respect to survival and disease-recurrence in CRC
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