2,017,104 research outputs found

    Sediment Management for Southern California Mountians, Coastal Plains and Shoreline. Part D: Special Inland Studies

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    In southern California the natural environmental system involves the continual relocation of sedimentary materials. Particles are eroded from inland areas where there is sufficient relief and, precipitation. Then, with reductions in hydraulic gradient along the stream course and at the shoreline, the velocity of surface runoff is reduced and there is deposition. Generally, coarse sand, gravel and larger particles are deposited near the base of the eroding surfaces (mountains and hills) and the finer sediments are deposited on floodplains, in bays or lagoons, and at the shoreline as delta deposits. Very fine silt and clay particles, which make up a significant part of the eroded material, are carried offshore where they eventually deposit in deeper areas. Sand deposited at the shoreline is gradually moved along the coast by waves and currents, and provides nourishment for local beaches. However, eventually much of this littoral material is also lost to offshore areas. Human developments in the coastal region have substantially altered the natural sedimentary processes, through changes in land use, the harvesting of natural resources (logging, grazing, and sand and gravel mining); the construction and operation of water conservation facilities and flood control structures; and coastal developments. In almost all cases these developments have grown out of recognized needs and have well served their primary purpose. At the time possible deleterious effects on the local or regional sediment balance were generally unforeseen or were felt to be of secondary importance. In 1975 a large-scale study of inland and coastal sedimentation processes in southern California was initiated by the Environmental Quality Laboratory at the California Institute of Technology and the Center for Coastal Studies at Scripps Institution of Oceanography. This volume is one of a series of reports from this study. Using existing data bases, this series attempts to define quantitatively inland and coastal sedimentation processes and identify the effects man has had on these processes. To resolve some issues related to long-term sediment management, additional research and data will be needed. In the series there are four Caltech reports that provide supporting studies for the summary report (EQL Report No. 17). These reports include: EQL Report 17-A Regional Geological History EQL Report 17-B Inland Sediment Movements by Natural Processes EQL Report 17-C Coastal Sediment Delivery by Major Rivers in Southern California EQL Report 17-D -- Special Inland Studies Additional supporting reports on coastal studies (shoreline sedimentation processes, control structures, dredging, etc.) are being published by the Center for Coastal Studies at Scripps Institution of Oceanography, La Jolla, California

    [68Ga]-DOTATOC-PET/CT for meningioma IMRT treatment planning

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    <p>Abstract</p> <p>Purpose</p> <p>The observation that human meningioma cells strongly express somatostatin receptor (SSTR 2) was the rationale to analyze retrospectively in how far DOTATOC PET/CT is helpful to improve target volume delineation for intensity modulated radiotherapy (IMRT).</p> <p>Patients and Methods</p> <p>In 26 consecutive patients with preferentially skull base meningioma, diagnostic magnetic resonance imaging (MRI) and planning-computed tomography (CT) was complemented with data from [<sup>68</sup>Ga]-DOTA-D Phe<sup>1</sup>-Tyr<sup>3</sup>-Octreotide (DOTATOC)-PET/CT. Image fusion of PET/CT, diagnostic computed tomography, MRI and radiotherapy planning CT as well as target volume delineation was performed with OTP-Masterplan<sup>®</sup>. Initial gross tumor volume (GTV) definition was based on MRI data only and was secondarily complemented with DOTATOC-PET information. Irradiation was performed as EUD based IMRT, using the Hyperion Software package.</p> <p>Results</p> <p>The integration of the DOTATOC data led to additional information concerning tumor extension in 17 of 26 patients (65%). There were major changes of the clinical target volume (CTV) which modify the PTV in 14 patients, minor changes were realized in 3 patients. Overall the GTV-MRI/CT was larger than the GTV-PET in 10 patients (38%), smaller in 13 patients (50%) and almost the same in 3 patients (12%). Most of the adaptations were performed in close vicinity to bony skull base structures or after complex surgery. Median GTV based on MRI was 18.1 cc, based on PET 25.3 cc and subsequently the CTV was 37.4 cc. Radiation planning and treatment of the DOTATOC-adapted volumes was feasible.</p> <p>Conclusion</p> <p>DOTATOC-PET/CT information may strongly complement patho-anatomical data from MRI and CT in cases with complex meningioma and is thus helpful for improved target volume delineation especially for skull base manifestations and recurrent disease after surgery.</p

    Az erdélyi magyar nyelvjárások anyagának feldolgozása és közzététele (11. szakasz) = Preparation and publication of the 11th volume of „Linguistic Atlas of the Hungarian Dialects of Rumania”

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    Az erdélyi magyar nyelvjárások anyagának feldolgozása a Magyar Nyelvtudományi Társaság és az ELTE összefogásával már 17 éve tart. Legfőbb eredménye A romániai magyar nyelvjárások atlasza, amely a jelen pályázattal a 11., záró kötetéhez érkezett. Az utolsó kötet tartalmazza az első óta megjelent, az atlasszal kapcsolatos írások válogatott bibliográfiáját és a teljes atlaszsorozat egyesített címszómutatóját is. A számítógépes technika segítségével nemcsak nyomtatott atlaszkötetek készültek, hanem olyan elektronikus adatbázis is, amely a térképeken kívül számítógépes nyelvföldrajzi szótárat tartalmaz. Az adatok birtokában korszerű, megbízható elemzések végezhetők. Az adatokat és elemzéseket a dialektológián kívül a néprajz és településtörténet is hasznosíthatja. | The systematization of data collected from Hungarian dialects of Transylvania has been going on for 17 years in cooperation between ELTE and Society of Hungarian Linguistics. The main result of this work is the publication of the Linguistic Atlas of the Hungarian Dialects of Rumania. After the 10 volumes published so far, another one will be finished within the present project. The last volume contains the bibliography of the articles written about the atlas and published since the first volume as well as the united index of the complete series. By means of computer technics applied, not only printed volumes are prepared, but an electronic data base too, containing a dictionary of the dialects in addition to the maps. In possession of data, up to date, reliable analyses can be carried out. Both data and analyses can be also used by ethnography, ethnology and settlement history or migration studies

    Patterns of regional diastolic function in the normal human left ventricle: An ultrafast computed tomographic study

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    AbstractThe detailed evaluation of regional diastolic filling at multiple ventricular levels in the normal human left ventricle has not previously been reported. Ultrafast computed tomography was used to characterize global and regional early diastolic filling in the left ventricle of 11 normal male volunteers. Regional early diastolic filling data from six distinct ventricular levels (apex to base) were fit to a third-order polynomial curve, and the peak rate of diastolic filling and time of peak filling were determined. Peak filling rate was 259 ± 17 ml/s (±SEM) as a global average, where peak filling rate referenced to end-diastolic volume and stroke volume across the levels examined was 3.78 ± 0.17 s−and 4.83 ± 0.20 s−respectively. Average filling fraction was 39 ± I%, and time to peak filling from end-systole was 145 ± 5 ms.Regional (tomographic) peak filling rates, except for the most apical level examined, were not statistically different across the ventricle. Filling fraction and time to peak filling were remarkably constant from one level to another. However, reference of regional peak filling rate to regional end-diastolic volume demonstrated significant nonuniformity from apex (120% of average for all levels) to base (87% of average for all levels). Peak filling rate referenced to tomographic stroke volume was less variable and not statistically different across the ventricle as a whole.In conclusion, values of regional absolute early peak diastolic ventricular filling rate or values normalized for regional end-diastolic volume are characteristically nonuniform across the left ventricle, whereas other variables such as filling fraction, time to peak filling and regional peak filling rate referenced to regional stroke volume are highly uniform. This confirms an intimate relation between rates of regional diastolic filling and regional ventricular size and stroke volume in the normal human heart

    Quantitative gated blood pool tomographic assessment of regional ejection fraction: Definition of normal limits

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    AbstractObjective. Our aim was to select a method of analysis for gated blood pool tomography that reduced variability in a group of normal subjects, allowed comparison with normal limit files and displayed results in the bull's-eye format.Background. Abnormalities in left ventricular function may not be accurately detected by measures of global function because hyperkuiesia in normal regions may compensate for abnormal regional function. Gated blood pool tomography acquires threedimensional data and offers advantages over other noninvasive modalities Tor quantitative assessment of global and regional function.Methods. Alternative methods for selecting the ventricular axis, calculating regional ejection fraction and choosing the number of ventricular divisions were studied In 15 normal volunteers to select the combination of parameter that produced the lowest variability in quantitative regional ejection fraction. Methods for quantitative comparison, of regional ejection fraction with normal limit files and for display in the bull's-eye format were also examined.Results. A fixed axis (the geometric center of the ventricle defined for end-diastole and used for end-systole) gave ejection fractions that were significantly higher in the lateral wall versus in the septum, 82 ± 8 (mean ± 1 SD) versus 39 ± 17 (p < 0.001) at the midcavity and 66 ± 11 versus 21 ± 20 (p < 0.001) at the base. A floating axis system (axis defined individually for end-diastole and end-systole and realigned at the center) gave more uniform regional ejection fraction: 63 ±6 versus 64 ± 8 (p = NS) at the midcavity and 44 ± 16 versus 45 ± 15 (p = NS) at the base. The coefficient of variability for regional ejection fraction was consistently lower using a floating axis. Calculating regional ejection fraction by dividing the regional stroke volume by the enddiastollc volume of the region gave a lower coefficient of variability and a more easily understood value than dividing the regional stroke volume by the total end-diastolic volume of the ventricle. Although the variability was lower using five versus nine ventricular divisions, nine regions offer greater spatial resolution. Comparison of regional ejection fraction with normal data identified regions > 2.5 SD below the mean as abnormal. We described the two-dimensional bull's-eye format as a method for displaying the regional three-dimensional data and illustrated abnormalities in patients with prior myocardial infarction.Conclusions. Gated blood pool tomography performed using a floating axis system, regional stroke volume calculation of ejection fraction and nine regions uses all the three-dimensional blood pool data to calculate regional ejection fraction, allow quantitative comparison with normal limit tiles, display the functional data in the two-dimensional bull's-eye format and demonstrate abnormalities in patients with myocardial infarction

    Evidence-Based Considerations for the Design of an Open-Source Ventilator: A Systematic Review

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    OBJECTIVE: To inform the design of open-source ventilators, we performed a systematic review of clinical practice guidelines (CPGs) to consolidate the evidence on mechanical ventilation strategies that result in improved patient-important outcomes for acute hypoxic respiratory failure. DATA SOURCES: We developed a search strategy to identify relevant CPGs from Ovid Medline, Ovid Medline In-Process & Other Non-Indexed Citations, Embase, the Cochrane Library, Mendeley, and Google scholar from 2010 to February 17, 2022. STUDY SELECTION: Using a two-step screening process with two independent reviewers, we included CPGs that made recommendations on mechanical ventilation strategies of interest. Guidelines that reported at least one recommendation about mechanical ventilation in ICU patients with acute hypoxic respiratory failure were included. DATA EXTRACTION: From the 13 eligible guidelines, we collected data on country, aim, patient population, impact on morbidity and mortality (effect size and CIs), recommendations, strength of Recommendation (as per Grading of Recommendations, Assessment, Development and Evaluations), and details of supporting evidence base. DATA SYNTHESIS: We identified three ventilation strategies that confer a mortality and morbidity benefit for ventilated patients with acute hypoxic respiratory failure: low-tidal volume ventilation, plateau pressures of less than 30 cm H2O, and higher positive end-expiratory pressure (PEEP). These moderate-to-strong recommendations were based on moderate-to-high certainty in evidence. We identified several other recommendations with no or minimal certainty in evidence. CONCLUSIONS: Our systematic review of international CPGs identified no recommendations favoring specific mode of ventilation and three ventilation strategies that confer mortality and morbidity benefits, backed by moderate-to-strong evidence. Ventilator design teams must include the ability to consistently provide and measure low-tidal volume ventilation, plateau pressures of less than 30 cm H2O, and higher PEEP into their designs. Based on our findings, we provide the first public framework for open-source ventilator design

    Management of pelvic lymphoceles after radical prostatectomy: A multicentre community based study

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    <p>Abstract</p> <p>Introduction</p> <p>Pelvic lymphoceles (LC) following radical prostatectomy (LC-RP) have an incidence up to 27%. LC-managements constitute 50% of surgical interventions performed in post-RP patients.</p> <p>Objectives</p> <p>To describe a therapeutic algorithm for LC-managements based on a community based representative retrospective study.</p> <p>Patients and methods: Multicentre data from 304 patients with LC-RP were retrospectively examined for LC-managements. RPs were performed by various surgeons from 67 urological departments. All patients had undergone 3 weeks rehabilitation in a specialized hospital where the data base was generated. Indications and results of therapeutic manoeuvres were used to develop a general concept for planning therapy decisions.</p> <p>Results</p> <p>Median age was 64 years. Complications occurred in 9% (28/304) of patients. Median LC-volume was 36 ml (range 20-1800 ml). There were more complications for LCs with ≥100 ml volume than those < 100 ml (27% versus 17%, p = 0.346). Conservative therapy was the standard in uncomplicated cases (87%, 239 of 276 patients), while intervention was done in 13% (puncture and/or drainage, surgery). Surgical intervention was performed significantly more often in complicated cases (82%, 23 from 28 patients; p < 0.001). Based on these data, LCs can be stratified into 3 groups depending on the size and clinical presentation. Therapeutic decisions were used to develop the illustrated new therapy algorithm.</p> <p>Conclusions</p> <p>This study based treatment algorithm provides a rationale approach with an accurate LC-classification as regard the indications and decision making for the available LC-RP-therapies. This could facilitate management decisions. Evaluation of this concept prospectively in large patient cohort is mandatory.</p

    CSF rhinorrhoea after endonasal intervention to the skull base (CRANIAL): A multicentre prospective observational study

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    Objective: Despite progress in endonasal skull-base neurosurgery, cerebrospinal fluid (CSF) rhinorrhoea remains common and significant. The CRANIAL study sought to determine 1) the scope of skull-base repair methods used, and 2) corresponding rates of postoperative CSF rhinorrhoea in the endonasal transsphenoidal approach (TSA) and the expanded endonasal approach (EEA) for skull-base tumors. Methods: A prospective observational cohort study of 30 centres performing endonasal skull-base neurosurgery in the UK and Ireland (representing 91% of adult units). Patients were identified for 6 months and followed up for 6 months. Data collection and analysis was guided by our published protocol and pilot studies. Descriptive statistics, univariate and multivariable logistic regression models were used for analysis. Results: A total of 866 patients were included - 726 TSA (84%) and 140 EEA (16%). There was significant heterogeneity in repair protocols across centres. In TSA cases, nasal packing (519/726, 72%), tissue glues (474/726, 65%) and hemostatic agents (439/726, 61%) were the most common skull base repair techniques. Comparatively, pedicled flaps (90/140, 64%), CSF diversion (38/140, 27%), buttresses (17/140, 12%) and gasket sealing (11/140, 9%) were more commonly used in EEA cases. CSF rhinorrhoea (biochemically confirmed or requiring re-operation) occurred in 3.9% of TSA (28/726) and 7.1% of EEA (10/140) cases. A significant number of patients with CSF rhinorrhoea (15/38, 39%) occurred when no intraoperative CSF leak was reported. On multivariate analysis, there may be marginal benefits with using tissue glues in TSA (OR: 0.2, CI: 0.1-0.7, p&amp;lt;0.01), but no other technique reached significance. There was evidence that certain characteristics make CSF rhinorrhoea more likely – such as previous endonasal surgery and the presence of intraoperative CSF leak. Conclusions: There is a wide range of skull base repair techniques used across centres. Overall, CSF rhinorrhoea rates across the UK and Ireland are lower than generally reported in the literature. A large proportion of postoperative leaks occurred in the context of occult intraoperative CSF leaks, and decisions for universal sellar repairs should consider the risks and cost-effectiveness of repair strategies. Future work could include longer-term, higher-volume studies, such as a registry; and high-quality interventional studies

    Sediment Management for Southern California Mountains, Coastal Plains and Shoreline. Part A: Regional Geological History

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    In southern California the natural environmental system involves the continual relocation of sedimentary materials. Particles are eroded from inland areas where there is sufficient relief and, precipitation. Then, with reductions in hydraulic gradient along the stream course and at the shoreline, the velocity of surface runoff is reduced and there is deposition. Generally, coarse sand, gravel and larger particles are deposited near the base of the eroding surfaces (mountains and hills) and the finer sediments are deposited on floodplains, in bays or lagoons, and at the shoreline as delta deposits. Very fine silt and clay particles, which make up a significant part of the eroded material, are carried offshore where they eventually deposit in deeper areas. Sand deposited at the shoreline is gradually moved along the coast by waves and currents, and provides nourishment for local beaches. However, eventually much of this littoral material is also lost to offshore areas. Human developments in the coastal region have substantially altered the natural sedimentary processes, through changes in land use, the harvesting of natural resources (logging, grazing, and sand and gravel mining); the construction and operation of water conservation facilities and flood control structures; and coastal developments. In almost all cases these developments have grown out of recognized needs and have well served their primary purpose. At the time possible deleterious effects on the local or regional sediment balance were generally unforeseen or were felt to be of secondary importance. In 1975 a large-scale study of inland and coastal sedimentation processes in southern California was initiated by the Environmental Quality Laboratory at the California Institute of Technology and the Center for Coastal Studies at Scripps Institution of Oceanography. This volume is one of a series of reports from this study. Using existing data bases, this series attempts to define quantitatively inland and coastal sedimentation processes and identify the effects man has had on these processes. To resolve some issues related to long-term sediment management, additional research and data will be needed. In the series there are four Caltech reports that provide supporting studies for the summary report (EQL Report No. 17). These reports include: EQL Report 17-A Regional Geological History EQL Report 17-B Inland Sediment Movements by Natural Processes EQL Report 17-C Coastal Sediment Delivery by Major Rivers in Southern California EQL Report 17-D -- Special Inland Studies Additional supporting reports on coastal studies (shoreline sedimentation processes, control structures, dredging, etc.) are being published by the Center for Coastal Studies at Scripps Institution of Oceanography, La Jolla, California
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