Metaanalyse individueller Patientendaten zur diagnostischen Genauigkeit der computertomographischen Koronarangiographie unter Einfluss der Prätestwahrscheinlichkeit

Zielsetzung. Ziel der Arbeit ist die Untersuchung des Zusammenhangs zwischen Patientencharakteristiken, der Prätestwahrscheinlichkeit (PTP) und der diagnostischen Genauigkeit der koronaren computertomographischen Angiographie (CCTA) in Patienten und Patientensubgruppen mit Verdacht auf eine koronare Herzkrankheit (KHK). Methoden. Das COME-CCT Projekt trägt individuelle Patientendaten (IPD) aus diagnostischen Genauigkeitsstudien zur CCTA zusammen, die Patienten mit einer klinischen Indikation zum Herzkatheter als Goldstandard zur Diagnose der obstruktiven KHK eingeschlossen haben. Diese wurden über eine systematische Suche identifiziert und die zugrundeliegenden IPD erhoben. Die positiven und negativen prädiktiven Werte (PPV und NPV) der CCTA wurden als Funktion der PTP der KHK über ein generalisiertes lineares gemischtes Regressionsmodell berechnet. Das Behandeln/Nicht-Behandeln-Schwellenwertmodell wurde zur Bestimmung des geeigneten PTP-Bereiches für die Durchführung der CCTA verwendet, indem die PTP definiert wird, ab der andere Gründe für Beschwerden in Betracht gezogen (PTP zu niedrig) oder andere diagnostische Verfahren angewendet werden sollten (PTP zu hoch). Die Schwellenwerte wurden durch die resultierenden Posttestwahrscheinlichkeiten von weniger als 15% im Falle einer negativen und über 50% im Falle einer positiven CCTA definiert. Zur Analyse der diagnostischen Genauigkeit in den relevanten Patientensubgruppen wurden die klinischen Variablen Alter, Geschlecht und die Art der Angina pectoris verwendet. Zudem wurde die diagnostische Genauigkeit zwischen Computertomographie(CT)-Scannern mit ≤64 und >64 Detektorzeilen verglichen. Resultate. Die individuellen Daten von 5332 Patienten aus 65 Studien wurden in die Metaanalyse eingeschlossen. In dem Behandeln/Nicht-Behandeln-Schwellenwertmodell erreichte die CCTA die höchste diagnostische Genauigkeit in dem Bereich von 7 bis 67% PTP mit einem NPV von 97.8% (95% Konfidenzintervall [95% CI] 96.4-98.7%) bei 7% PTP und 85.0% (95% CI 80.2-88.9%) bei 67% PTP und einem entsprechenden PPV von 50.9% (95% CI 43.3-57.7%) und 82.7% (95% CI 78.3-86.2%). Im Vergleich zu CT mit bis zu 64 Detektorzeilen zeigten CT mit mehr als 64 Detektorzeilen eine höhere Sensitivität und Spezifität. Die diagnostische Genauigkeit der CCTA erzielte ähnliche Ergebnisse bei den verschiedenen Typen der Angina pectoris und zeigte eine leicht geringere diagnostische Genauigkeit bei Frauen im Vergleich zu Männern und bei Patienten älter als 75 Jahre. Schlussfolgerung. Die CCTA hat eine KHK zuverlässig bei Patienten ausgeschlossen, deren Wahrscheinlichkeit für das Vorliegen einer KHK vor der Untersuchung zwischen 7 und 67% liegt. CT mit mehr als 64 Detektorzeilen sollten vornehmlich verwendet werden. In Frauen und bei Patienten älter als 75 Jahre zeigte die CCTA eine leicht geringere diagnostische Leistung. Die Art der Angina pectoris hatte keinen Einfluss auf die diagnostische Genauigkeit der CCTA.Objectives. To analyse the association between individual patient characteristics, their pretest probability (PTP) and the diagnostic performance of coronary computed tomography angiography (CCTA) in patients with suspected coronary artery disease (CAD). Methods. The Collaborative Meta-Analysis of Cardiac Computed Tomography (COME-CCT) was formed to pool patient-level data from diagnostic accuracy studies of CCTA enrolling patients with a clinical indication for invasive coronary angiography as the reference standard for obstructive CAD. A systematic search identified eligible primary studies from which individual participant data (IPD) were sought. The positive and negative predictive values (PPV and NPV) of CCTA as a function of PTP of CAD were analysed by a generalised linear mixed model. In defining the thresholds of PTP when other causes for symptoms (PTP too low) or other diagnostic methods should be applied (PTP too high), the no-treat/treat threshold model determined the range of appropriate PTP for CCTA based on obtained posttest probabilities of below 15% in case of negative CCTA and above 50% in case of positive CCTA. Gender, angina pectoris type, and age were used as clinical variables to evaluate the diagnostic performance in relevant subgroups. Further outcomes were the diagnostic performance of CCTA using ≤64 versus (vs) >64 detector rows. Results. Individual data of 5332 patients from 65 eligible diagnostic accuracy studies were included. Applying a no-treat/treat threshold model, the highest diagnostic performance of CCTA was achieved in the range of 7 to 67% PTP with a NPV of 97.8% (95% confidence interval [95% CI] 96.4 to 98.7%) at 7% PTP and 85.0% (95% CI 80.2 to 88.9%) at 67% PTP and a PPV of 50.9% (95% CI 43.3 to 57.7%) and 82.7% (95% CI 78.3 to 86.2) accordingly. CCTA with >64 detector rows improved diagnostic performance of CCTA in sensitivity and specificity in comparison to CCTA using up to 64 detector rows. CCTA showed slightly higher diagnostic performance in men compared with women. While the diagnostic performance of CCTA in patients with different types of angina pectoris was similar, it was lower in patients older than 75. Conclusions. In patients with a PTP ranging from 7 to 67% CCTA reliably ruled out obstructive CAD while also achieving a good positive predictive value. Female patients and patients older than 75 had slightly lower diagnostic performance of CCTA. CT using >64 detector rows should be used if possible. The type of angina pectoris had no influence on diagnostic performance

Coastal water source of short‐lived halocarbons in New England

Short‐lived halocarbon tracers were used to investigate marine influences on air quality in a coastal region of New England. Atmospheric measurements made at the University of New Hampshire\u27s Observing Station at Thompson Farm (TF) in Durham, New Hampshire, indicate that relatively large amounts of halocarbons are emitted from local estuarine and coastal oceanic regions. Bromine‐containing halocarbons of interest in this work include bromoform (CHBr3) and dibromomethane (CH2Br2). The mean mixing ratios of CHBr3 and CH2Br2 from 11 January to 5 March 2002 were 2.6 pptv and 1.6 pptv, and from 1 June to 31 August 2002 mean mixing ratios were 5.9 pptv and 1.4 pptv, respectively. The mean mixing ratio of CHBr3 was not only highest during summer, but both CHBr3 and CH2Br2 exhibited large variability in their atmospheric mixing ratios during this season. We attribute the greater variability to increased production combined with faster atmospheric removal rates. Other seasonal characteristics of CHBr3 and CH2Br2 in the atmosphere, as well as the impact of local meteorology on their distributions at this coastal site, are discussed. Tetrachloroethene (C2Cl4) and trichloroethene (C2HCl3) were used to identify time periods influenced by urban emissions. Additionally, measurements of CHBr3, CH2Br2, C2Cl4, methyl iodide (CH3I), and ethyl iodide (C2H5I) were made at TF and five sites throughout the nearby Great Bay estuarine area between 18 and 19 August 2003. These measurements were used to elucidate the effect of the tidal cycle on the distributions of these gases. The mean mixing ratios of CHBr3, CH2Br2, CH3I, and C2H5I were ∼82%, 46%, 14%, and 17% higher, respectively, near the coast compared to inland sites, providing evidence for a marine source of short‐lived halocarbons at TF. Correlation between the tidal cycle and atmospheric concentrations of marine tracers on the night of 18 August 2003 showed that the highest values for the brominated species occurred ∼2–3 hours after high tide. Emission fluxes of CHBr3, CH2Br2, CH3I, and C2H5I on this night were estimated to be 26 ± 57, 4.7 ± 5.4, 5.9 ± 4.6, and 0.065 ± 0.20 nmol m−2 h−1, respectively. Finally, the anthropogenic source strength of CHBr3 was calculated to determine its impact on atmospheric levels observed in this region. Although our results indicate that anthropogenic contributions could potentially range from 15 to 60% of the total dissolved CHBr3 in the Great Bay, based on the observed ratio of CH2Br2/CHBr3 and surface seawater measurements in the Gulf of Maine, it appears unlikely that anthropogenic activities are a significant source of CHBr3 in the region

Emotional and behavioral symptoms in neurodegenerative disease: a model for studying the neural bases of psychopathology.

Disruptions in emotional, cognitive, and social behavior are common in neurodegenerative disease and in many forms of psychopathology. Because neurodegenerative diseases have patterns of brain atrophy that are much clearer than those of psychiatric disorders, they may provide a window into the neural bases of common emotional and behavioral symptoms. We discuss five common symptoms that occur in both neurodegenerative disease and psychopathology (i.e., anxiety, dysphoric mood, apathy, disinhibition, and euphoric mood) and their associated neural circuitry. We focus on two neurodegenerative diseases (i.e., Alzheimer's disease and frontotemporal dementia) that are common and well characterized in terms of emotion, cognition, and social behavior and in patterns of associated atrophy. Neurodegenerative diseases provide a powerful model system for studying the neural correlates of psychopathological symptoms; this is supported by evidence indicating convergence with psychiatric syndromes (e.g., symptoms of disinhibition associated with dysfunction in orbitofrontal cortex in both frontotemporal dementia and bipolar disorder). We conclude that neurodegenerative diseases can play an important role in future approaches to the assessment, prevention, and treatment of mental illness

High‐Tensile Strength, Composite Bijels through Microfluidic Twisting

Rope making is a millennia old technique to collectively assemble numerous weak filaments into flexible and high tensile strength bundles. However, delicate soft matter fibers lack the robustness to be twisted into bundles by means of mechanical rope making tools. Here, weak microfibers with tensile strengths of a few kilopascals are combined into ropes via microfluidic twisting. This is demonstrated for recently introduced fibers made of bicontinuous interfacially jammed emulsion gels (bijels). Bijels show promising applications in use as membranes, microreactors, energy and healthcare materials, but their low tensile strength make reinforcement strategies imperative. Hydrodynamic twisting allows to produce continuous bijel fiber bundles of controllable architecture. Modelling the fluid flow field reveals the bundle geometry dependence on a subtle force balance composed of rotational and translational shear stresses. Moreover, combining multiple bijel fibers of different compositions enables the introduction of polymeric support fibers to raise the tensile strength to tens of megapascals, while simultaneously preserving the liquid like properties of the bijel fibers for transport applications. Hydrodynamic twisting shows potentials to enable the combination of a wide range of materials resulting in composites with features greater than the sum of their parts

Method and apparatus for joining metals

The present invention discloses methods and apparatus for joining of two workpieces. The present invention includes special preparation of the joining ends of the two workpieces to be joined. Methods of the present invention include delivering a high current, low voltage pulse to a pair of workpieces to be joined while applying and maintaining a constantly high load on said workpieces to thereby join the workpieces.Board of Regents, University of Texas Syste

Age-related changes in emotional behavior: Evidence from a 13-year longitudinal study of long-term married couples.

We examined age-related changes in emotional behavior in a sample of middle-aged and older long-term married couples over a 13-year period. Data were collected at 3 waves, each occurring 5 to 6 years apart. For the present study, only couples who participated in all 3 waves were examined (n = 87). Couples were either in the middle-aged group (40-50 years old, married at least 15 years) or the older group (60-70 years old, married at least 35 years). At each wave, couples engaged in 15-min unrehearsed conversations about an area of disagreement in their marriage. Emotional behaviors during the conversation were objectively coded using the Specific Affect Coding System. Latent growth curve analyses revealed that, for both husbands and wives, negative emotional behavior (primarily belligerence, defensiveness, fear/tension, and whining) decreased and positive emotional behavior (primarily humor, enthusiasm, and validation) increased with age. Findings generalized across middle-aged and older cohorts and levels of marital satisfaction. These findings support theories that suggest that positive emotion increases and negative emotion decreases with age, expanding upon previous findings by examining objectively coded emotional behaviors longitudinally in an interpersonal context. (PsycINFO Database Record (c) 2020 APA, all rights reserved)