5,356 research outputs found
Analyse von Strahlenschäden in menschlichen Metaphasechromosomen nach fluoreszenz in situ Hybridisierung
Surgical Treatment of Neer Group VI Proximal Humeral Fractures: Retrospective Comparison of PHILOS® and Hemiarthroplasty
Background: Neer Group VI proximal humeral fractures often are related to persistent disability despite surgical treatment. We retrospectively compared the outcome after open reduction and internal fixation with the PHILOS® plate or primary hemiarthroplasty in patients with Neer Group VI fractures focusing on complications, shoulder function, health-related quality of life (SF-36), and potential risk factors for complications. Questions/purposes: The aim of this study was to compare the PHILOS® plate with primary hemiarthroplasty for treatment of specific Neer Group VI fractures. We asked whether (1) both procedures have comparable clinical and radiologic complication rates; (2) one procedure is superior in terms of revision rate; (3) objective and subjective shoulder function (Constant-Murley score) and health-related quality of life (SF-36) were comparable in both groups at final followup; and (4) there are clinical or radiologic predictors for complications in any group? Methods: Between 2002 and 2007, 44 consecutive patients (mean, 75.2years) with a Neer Group VI proximal humeral fracture were included. Twenty-two patients treated with a PHILOS® plate were compared with 22 patients treated by primary hemiarthroplasty. Both groups were similar in all criteria. At minimum followup of 12months (mean, 30months; range, 12-83months), radiographic control, Constant-Murley score, and SF-36 were performed. Results : Fourteen patients with complications (63.6%) were counted in the PHILOS® plate group, of which 10 (45.4%) needed revision surgery, mostly as a result of avascular necrosis and screw cut-outs. In the primary hemiarthroplasty group, only one patient needed revision surgery (4.5%). Smoking and steroid therapy were substantially associated with complications in the PHILOS® plate group. There were no differences between the two groups regarding Constant-Murley or SF-36 scores. Conclusions : Angular stable open reduction and internal fixation was associated with high complication and revision rates, especially in patients who smoked and those receiving steroid therapy. Primary hemiarthroplasty provides limited function, which had little influence on the quality of life in this elderly collective. There are predictive factors for complications after the treatment of Neer Group VI proximal humeral fractures with the PHILOS® plate. Primary hemiarthroplasty remains a good option, especially when treating elderly patients. Level of Evidence: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidenc
Radially polarized passively mode-locked thin-disk laser oscillator emitting sub-picosecond pulses with an average output power exceeding the 100 W level
We report on a high-power passively mode-locked radially polarized Yb:YAG thin-disk oscillator providing 125 W of average output power. To the best of our knowledge, this is the highest average power ever reported from a mode-locked radially polarized oscillator without subsequent amplification stages. Mode-locking was achieved by implementing a SESAM as the cavity end mirror and the radial polarization of the LG*01 mode was obtained by means of a circular Grating Waveguide Output Coupler. The repetition rate was 78 MHz. A pulse duration of 0.97 ps and a spectral bandwidth of 1.4 nm (FWHM) were measured at the maximum output power. This corresponds to a pulse energy of 1.6 μJ and a pulse peak power of 1.45 MW. A high degree of radial polarization of 97.3 ± 1% and an M2-value of 2.16 which is close to the theoretical value for the LG*01 doughnut mode were measured
COMBINED OZONE AND ULTRASOUND PROCESS FOR THE DESTRUCTION OF 1,4-DIOXANE IN CONTINUOUS FLOW REACTOR
Clean water is essential to life. Growth in world population, changing diets, and a warming climate are driving an increase in the demand for water. Better management of water resources will help prevent scarcity, but in order to fully meet the future demand for safe, clean drinking water, new water treatment technologies are needed. This dissertation investigates a technology which is not well understood; the combination of ozone and ultrasound as potentially an efficient technology. Since nearly all previously published studies of combined ozone/ultrasound utilized batch reactors, a continuous flow reactor was constructed for this research. 1,4-Dioxane, henceforth referred to as dioxane, was chosen to evaluate the effectiveness of the combined ozone/ultrasound process. Dioxane is commonly detected in surface and groundwater and is a suspected human carcinogen. A recalcitrant contaminant, it resists direct oxidation by chlorine, oxygen, ozone, and biological treatment. It is miscible in water and doesn't sorb readily to organic matter, so it spreads rapidly in groundwater contamination plumes. It also resists air stripping and filtration, including reverse osmosis. For these reasons, dioxane makes an excellent candidate to measure the effectiveness of advanced oxidation processes, such as combined ozone/ultrasound. The treatment of dioxane by advanced oxidation processes has been studied extensively in the past. However, only one study has been published using combined ozone/ultrasound, and it was done in a batch reactor operating at a high ultrasonic frequency. The reactor built for this study also permitted reactor pressurization effects to be studied in a manner that has not been reported before for the combined ozone/ultrasound process. In this study, the combination of ozone and ultrasound was found to cause synergistic removal of dioxane from drinking water; the removal achieved by the combination significantly exceeded the sum of the removal achieved by ozone and ultrasound separately. In fact, the combination of ozone and ultrasound was found to remove more than double the dioxane that would be removed by doing both treatment processes separately. Ultrasound (20 kHz) was ineffective in removing dioxane alone, achieving less than 20% removal. At 16 mg/L, ozone alone was found to achieve removal of up to 86% after a 16 minute treatment time, but appears sensitive to matrix effects, especially pH. When ultrasound was combined with just 1.2 mg/L of aqueous ozone, over 90% removal occurred after a 16 minute treatment. Removal of dioxane was found to be driven not by ozone itself, but by radicals, suggesting that the decomposition of ozone is responsible for the generation of radical species and subsequent removal of dioxane. Ultrasound was found to increase the decomposition of ozone and appeared to be driving increased mass transfer of ozone into the aqueous phase. Modest reactor pressure appears to aid dioxane removal, but further increases in pressure did not appear to further enhance removal. An empirical model was constructed using a form similar to the Chick & Watson model for disinfection. Given inputs of initial aqueous ozone concentration, initial dioxane concentration, treatment time, and ultrasonic power, the model is able to predict effluent concentrations of dioxane with a relative root mean squared error of less than 5%. Additionally, RCT and mass balance analyses were performed, and both analysis techniques suggested that the removal of dioxane is dependent on the consumption of aqueous ozone. Spiked drinking water is representative of water that has undergone conventional treatment but requires a polishing step, and the combined ozone/ultrasound has shown promise as a polishing technology. Owing to its recalcitrance, prevalence, and mobility, dioxane represents a real and challenging groundwater contaminant, and combined ozone/ultrasound has shown promise as a groundwater treatment option. Additionally, the process is capable of dioxane removal in a pH range of 4-10. This pH independence, coupled with its ability to degrade recalcitrant contaminants, suggests that combined ozone/ultrasound holds promise as an industrial wastewater treatment option, too. The removal achieved by both ozone and combined ozone/ultrasound was an order of magnitude greater than what has been reported in previously published reports. However, a comparison of cost effectiveness relative to other advanced oxidation processes remains an area for future study. Finally, the combined ozone/ultrasound process holds promise as a drinking water treatment option in remote areas, since it requires only electricity. As a promising technology for polishing water for reuse, treating contaminated groundwater, treating industrial wastewater, and potentially improving access to safe drinking water in remote areas, combined ozone/ultrasound could aid in meeting global water demand in the future.Civil Engineerin
Impacted maxillary canines and root resorptions of neighbouring teeth: a radiographic analysis using cone-beam computed tomography
The study analyses the location of impacted maxillary canines and factors influencing root resorptions of adjacent teeth using cone-beam computed tomography (CBCT). In addition, the interrater reliability between observers of two different dental specialties for radiographic parameters will be evaluated. CBCT images of patients who were referred for radiographic localization of impacted maxillary canines and/or suspicion of root resorptions of adjacent teeth were included. The study analysed the exact three-dimensional location of the impacted canines in the anterior maxilla, frequency and extent of root resorptions, and potential influencing factors. To assess interrater agreement, Cohen's correlation parameters were calculated. This study comprises 113 patients with CBCT scans, and 134 impacted canines were analysed retrospectively. In the patients evaluated, 69 impacted canines were located palatally (51.49 per cent), 41 labially (30.60 per cent), and 24 (17.91 per cent) in the middle of the alveolar process. Root resorptions were found in 34 lateral incisors (25.37 per cent), 7 central incisors (5.22 per cent), 6 first premolars (4.48 per cent), and 1 second premolar (0.75 per cent). There was a significant correlation between root resorptions on adjacent teeth and localization of the impacted canine in relation to the bone, as well as vertical localization of the canine. Interrater agreement showed values of 0.546-0.877. CBCT provides accurate information about location of the impacted canine and prevalence and degree of root resorption of neighbouring teeth with high interrater correlation. This information is of great importance for surgeons and orthodontists for accurate diagnostics and interdisciplinary treatment plannin
Calibration of TCCON column-averaged CO2: the first aircraft campaign over European TCCON sites
The Total Carbon Column Observing Network (TCCON) is a ground-based network of Fourier Transform Spectrometer (FTS) sites around the globe, where the column abundances of CO2, CH4, N2O, CO and O2 are measured. CO2 is constrained with a precision better than 0.25% (1-σ). To achieve a similarly high accuracy, calibration to World Meteorological Organization (WMO) standards is required. This paper introduces the first aircraft calibration campaign of five European TCCON sites and a mobile FTS instrument. A series of WMO standards in-situ profiles were obtained over European TCCON sites via aircraft and compared with retrievals of CO2 column amounts from the TCCON instruments. The results of the campaign show that the FTS measurements are consistently biased 1.1% ± 0.2% low with respect to WMO standards, in agreement with previous TCCON calibration campaigns. The standard a priori profile for the TCCON FTS retrievals is shown to not add a bias. The same calibration factor is generated using aircraft profiles as a priori and with the TCCON standard a priori. With a calibration to WMO standards, the highly precise TCCON CO2 measurements of total column concentrations provide a suitable database for the calibration and validation of nadir-viewing satellite
Genes in the postgenomic era
We outline three very different concepts of the gene - 'instrumental', 'nominal', and 'postgenomic'. The instrumental gene has a critical role in the construction and interpretation of experiments in which the relationship between genotype and phenotype is explored via hybridization between organisms or directly between nucleic acid molecules. It also plays an important theoretical role in the foundations of disciplines such as quantitative genetics and population genetics. The nominal gene is a critical practical tool, allowing stable communication between bioscientists in a wide range of fields grounded in well-defined sequences of nucleotides, but this concept does not embody major theoretical insights into genome structure or function. The post-genomic gene embodies the continuing project of understanding how genome structure supports genome function, but with a deflationary picture of the gene as a structural unit. This final concept of the gene poses a significant challenge to conventional assumptions about the relationship between genome structure and function, and between genotype and phenotype
Periods of High Intensity Solar Proton Flux
Analysis is presented for times during a space mission that specified solar proton flux levels are exceeded. This includes both total time and continuous time periods during missions. Results for the solar maximum and solar minimum phases of the solar cycle are presented and compared for a broad range of proton energies and shielding levels. This type of approach is more amenable to reliability analysis for spacecraft systems and instrumentation than standard statistical models
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