973 resultados para Galilei, Galileo, 1564-1642.


Relevância:

10.00% 10.00%

Publicador:

Resumo:

To explore relevant changes in unexplained intraoperative bleeding, we evaluated elements of the final steps of the coagulation cascade in 226 consecutive patients undergoing elective surgery. Patients were stratified for the occurrence of unexplained intraoperative bleeding according to predefined criteria. Twenty patients (8.8%) developed unexplained bleeding. The median intraoperative blood loss was 1350 mL (bleeders) and 400 mL (nonbleeders) (P < 0.001). Fibrinogen and Factor XIII (F. XIII) were more rapidly consumed in bleeders (P < 0.001). Soluble fibrin formation (fibrin monomer) was increased in bleeders throughout surgery (P < or = 0.014). However, F. XIII availability per unit thrombin generated was significantly decreased in bleeders before, during, and after surgery (P < or = 0.051). Computerized thrombelastography showed a parallel, significant reduction in clot firmness. We suggest that mild preexisting coagulopathy is not rare in surgical patients and probably can result in clinically relevant intraoperative bleeding. This hemostatic disorder shows impaired clot firmness, probably secondary to decreased cross-linking (due to a loss of F. XIII, both in absolute measures and per unit thrombin generated). We suggest that the application of F. XIII might be worthwhile to test in a prospective clinical trial to increase clot firmness in patients at risk for this intraoperative coagulopathy.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The aim of this study was to evaluate the ability of dual energy X-rays absorptiometry (DXA) areal bone mineral density (aBMD) measured in different regions of the proximal part of the human femur for predicting the mechanical properties of matched proximal femora tested in two different loading configurations. 36 pairs of fresh frozen femora were DXA scanned and tested until failure in two loading configurations: a fall on the side or a one-legged standing. The ability of the DXA output from four different regions of the proximal femur in predicting the femoral mechanical properties was measured and compared for the two loading scenarios. The femoral neck DXA BMD was best correlated to the femoral ultimate force for both configurations and predicted significantly better femoral failure load (R2=0.80 vs. R2=0.66, P<0.05) when simulating a side than when simulating a standing configuration. Conversely, the work to failure was predicted similarly for both loading configurations (R2=0.54 vs. R2=0.53, P>0.05). Therefore, neck BMD should be considered as one of the key factors for discriminating femoral fracture risk in vivo. Moreover, the better predictive ability of neck BMD for femoral strength if tested in a fall compared to a one-legged stance configuration suggests that DXA's clinical relevance may not be as high for spontaneous femoral fractures than for fractures associated to a fall.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

An ever increasing number of low Earth orbiting (LEO) satellites is, or will be, equipped with retro-reflectors for Satellite Laser Ranging (SLR) and on-board receivers to collect observations from Global Navigation Satellite Systems (GNSS) such as the Global Positioning Sys- tem (GPS) and the Russian GLONASS and the European Galileo systems in the future. At the Astronomical Insti- tute of the University of Bern (AIUB) LEO precise or- bit determination (POD) using either GPS or SLR data is performed for a wide range of applications for satellites at different altitudes. For this purpose the classical numeri- cal integration techniques, as also used for dynamic orbit determination of satellites at high altitudes, are extended by pseudo-stochastic orbit modeling techniques to effi- ciently cope with potential force model deficiencies for satellites at low altitudes. Accuracies of better than 2 cm may be achieved by pseudo-stochastic orbit modeling for satellites at very low altitudes such as for the GPS-based POD of the Gravity field and steady-state Ocean Circula- tion Explorer (GOCE).

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Compared with term-born infants, preterm infants have increased respiratory morbidity in the first year of life. We investigated whether lung function tests performed near term predict subsequent respiratory morbidity during the first year of life and compared this to standard clinical parameters in preterms.The prospective birth cohort included randomly selected preterm infants with and without bronchopulmonary dysplasia. Lung function (tidal breathing and multiple-breath washout) was measured at 44 weeks post-menstrual age during natural sleep. We assessed respiratory morbidity (wheeze, hospitalisation, inhalation and home oxygen therapy) after 1 year using a standardised questionnaire. We first assessed the association between lung function and subsequent respiratory morbidity. Secondly, we compared the predictive power of standard clinical predictors with and without lung function data.In 166 preterm infants, tidal volume, time to peak tidal expiratory flow/expiratory time ratio and respiratory rate were significantly associated with subsequent wheeze. In comparison with standard clinical predictors, lung function did not improve the prediction of later respiratory morbidity in an individual child.Although associated with later wheeze, noninvasive infant lung function shows large physiological variability and does not add to clinically relevant risk prediction for subsequent respiratory morbidity in an individual preterm.

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Zielsetzung: Diese Studie untersuchte die Validität und Reliabilität von verschiedenen visuellen dentalen Vergrösserungshilfen in Bezug auf die okklusale Kariesdiagnostik mit Hilfe des International Caries Detection and Assessment System (ICDAS). Material und Methode: Die Okklusalflächen von 100 extrahierten Zähnen wurde an einer zuvor bestimmten Stelle von 10 Studenten (5 Studenten des 3. Jahreskurses (Bachelor-Studenten) und 5 Studenten des 4. Jahreskurses (Master-Studenten) der Zahnmedizinischen Kliniken der Universität Bern) und 4 Zahnärzten visuell untersucht und nach ICDAS auf das Vorhandensein und die Tiefe einer kariösen Läsion beurteilt. Die Beurteilung der Zähne erfolgte je zwei Mal von blossem Auge, mit einem Galilei-Lupensystem (2.5x Vergrösserung), mit einem Kepler-Lupensystem (4.5x Vergrösserung) und mit dem Operationsmikroskop (10x Vergrösserung) mit mindestens 24 Stunden Abstand zwischen den jeweiligen Untersuchungen. Als Goldstandard diente die Histologie. Die statistische Auswertung der Untersuchungen erfolgte mit der Berechnung der Kappa-Koeffizienten für die Intra- und Inter-Untersucher Reliabilität sowie einer Bayes-Analyse durch Ermittlung von Sensitivität, Spezifität und der Fläche unter der Receiver Operating Characteristic Kurve (AUC). Ergebnisse: Bei den Untersuchungsdurchläufen, welche mit dentalen Vergrösserungshilfen für die Diagnostik der okklusalen Zahnoberflächen durchgeführt wurden, sank die Anzahl der mit einem ICDAS-Code 0 (gesunde Zahnoberfläche) beurteilten Zähne, während die Quantität des Codes 3 (Schmelzeinbruch) mit höheren Vergrösserungen drastisch zunahm. Mit steigendem Vergrösserungsfaktor liessen sich sowohl mehr Schmelzkaries als auch Dentinkaries richtig erkennen (bessere Sensitivität), im Gegenzug sanken aber die Werte der Spezifität auf ein klinisch unakzeptables Niveau. Während der Abfall der Spezifität und AUC-Werte bei der Beurteilung von Schmelzkaries unter Verwendung von kleinen Vergrösserungen lediglich einen Trend darstellte, waren die Verschlechterungen in der Diagnostik bei der Dentinkaries unter der Zuhilfenahme von höheren Vergrösserungen häufig signifikant. So stiegen zum Beispiel bei den Zahnärzten die Werte der Sensitivität (Bandbreite) auf dem D3-Diagnostikniveau von 0.47 (0.17-0.79) bei dem Durchlauf von Auge auf 0.91 (0.83-1.00) bei der Benutzung des Operationsmikroskopes an, während jedoch die Spezifitätswerte (Bandbreite) von 0.78 (0.58-0.95) auf 0.30 (0.07-0.55) sanken. Ebenfalls einen negativen Einfluss von optischen Hilfsmitteln zeigte sich bei der Inter-Untersucher Reliabilität, während die Intra-Untersucher Reliabilität unbeeinflusst blieb. Die persönliche klinische Erfahrung scheint sowohl in Bezug auf das Mass der Übereinstimmung visueller Kariesdiagnostik als auch auf die Präferenz bei der Vergabe der ICDAS-Codes und somit auf die Werte der Validität einen wesentlichen Faktor auszumachen. Die Studenten erreichten die besten Werte der Sensitivität, indes die Zahnärzte dies bei der Spezifität erzielten. Schlussfolgerung: Insgesamt zeigte sich, dass ICDAS nicht für den zusätzlichen Gebrauch von optischen Vergrösserungen konzipiert wurde. Da es auf Grund von der Zuhilfenahme von dentalen Vergrösserungen zu mehr und unnötigen invasiven Behandlungsentscheidungen kommen könnte, ist von der Zuhilfenahme derselben für die okklusale Kariesdiagnostik mit ICDAS abzuraten.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Therapeutic angiogenesis is an attractive strategy to treat patients suffering from ischaemic conditions and vascular endothelial growth factor-A (VEGF) is the master regulator of blood vessel growth. However, VEGF can induce either normal or aberrant angiogenesis depending on its dose localized in the microenvironment around each producing cell in vivo and on the balanced stimulation of platelet-derived growth factor-BB (PDGF-BB) signalling, responsible for pericyte recruitment. At the doses required to induce therapeutic benefit, VEGF causes new vascular growth essentially without sprouting, but rather through the alternative process of intussusception, or vascular splitting. In the present article, we briefly review the therapeutic implications of controlling VEGF dose on one hand and pericyte recruitment on the other, as well as the key features of intussusceptive angiogenesis and its regulation.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Remote sensing observations meet some limitations when used to study the bulk atmospheric composition of the giant planets of our solar system. A remarkable example of the superiority of in situ probe measurements is illustrated by the exploration of Jupiter, where key measurements such as the determination of the noble gases׳ abundances and the precise measurement of the helium mixing ratio have only been made available through in situ measurements by the Galileo probe. This paper describes the main scientific goals to be addressed by the future in situ exploration of Saturn placing the Galileo probe exploration of Jupiter in a broader context and before the future probe exploration of the more remote ice giants. In situ exploration of Saturn׳s atmosphere addresses two broad themes that are discussed throughout this paper: first, the formation history of our solar system and second, the processes at play in planetary atmospheres. In this context, we detail the reasons why measurements of Saturn׳s bulk elemental and isotopic composition would place important constraints on the volatile reservoirs in the protosolar nebula. We also show that the in situ measurement of CO (or any other disequilibrium species that is depleted by reaction with water) in Saturn׳s upper troposphere may help constraining its bulk O/H ratio. We compare predictions of Jupiter and Saturn׳s bulk compositions from different formation scenarios, and highlight the key measurements required to distinguish competing theories to shed light on giant planet formation as a common process in planetary systems with potential applications to most extrasolar systems. In situ measurements of Saturn׳s stratospheric and tropospheric dynamics, chemistry and cloud-forming processes will provide access to phenomena unreachable to remote sensing studies. Different mission architectures are envisaged, which would benefit from strong international collaborations, all based on an entry probe that would descend through Saturn׳s stratosphere and troposphere under parachute down to a minimum of 10 bar of atmospheric pressure. We finally discuss the science payload required on a Saturn probe to match the measurement requirements.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Eosinophil-associated diseases often present with life-threatening manifestations and/or chronic organ damage. Currently available therapeutic options are limited to a few drugs that often have to be prescribed on a lifelong basis to keep eosinophil counts under control. In the past 10 years, treatment options and outcomes in patients with clonal eosinophilic and other eosinophilic disorders have improved substantially. Several new targeted therapies have emerged, addressing different aspects of eosinophil expansion and inflammation. In this review, we discuss available and currently tested agents as well as new strategies and drug targets relevant to both primary and secondary eosinophilic diseases, including allergic disorders.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

We studied sediment cores from Lake Vens (2,327 m asl), in the Tinée Valley of the SW Alps, to test the paleoseismic archive potential of the lake sediments in this particularly earthquake-sensitive area. The historical earthquake catalogue shows that moderate to strong earthquakes, with intensities of IX–X, have impacted the Southern Alps during the last millennium. Sedimentological (X-ray images, grain size distribution) and geochemical (major elements and organic matter) analyses show that Lake Vens sediments consist of a terrigenous, silty material (minerals and organic matter) sourced from the watershed and diatom frustules. A combination of X-ray images, grain-size distribution, major elements and magnetic properties shows the presence of six homogenite-type deposits interbedded in the sedimentary background. These sedimentological features are ascribed to sediment reworking and grain sorting caused by earthquake-generated seiches. The presence of microfaults that cross-cut the sediment supports the hypothesis of seismic deposits in this system. A preliminary sediment chronology is provided by 210Pb measurement and AMS 14C ages. According to the chronology, the most recent homogenite events are attributable to damaging historic earthquakes in AD 1887 (Ligure) and 1564 (Roquebillière). Hence, the Lake Vens sediment recorded large-magnitude earthquakes in the region and permits a preliminary estimate of recurrence time for such events of ~400 years.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Immunomodulation is a common feature of chronic helminth infections and mainly attributed to the secretion of bioactive molecules, which target and modify host immune cells. In this study, we show that the helminth immunomodulator AvCystatin, a cysteine protease inhibitor, induces a novel regulatory macrophage (Mreg; AvCystatin-Mreg), which is sufficient to mitigate major parameters of allergic airway inflammation and colitis in mice. A single adoptive transfer of AvCystatin-Mreg before allergen challenge suppressed allergen-specific IgE levels, the influx of eosinophils into the airways, local and systemic Th2 cytokine levels, and mucus production in lung bronchioles of mice, whereas increasing local and systemic IL-10 production by CD4(+) T cells. Moreover, a single administration of AvCystatin-Mreg during experimentally induced colitis strikingly reduced intestinal pathology. Phenotyping of AvCystatin-Mreg revealed increased expression of a distinct group of genes including LIGHT, sphingosine kinase 1, CCL1, arginase-1, and costimulatory molecules, CD16/32, ICAM-1, as well as PD-L1 and PD-L2. In cocultures with dendritic cells and CD4(+) T cells, AvCystatin-Mreg strongly induced the production of IL-10 in a cell-contact-independent manner. Collectively, our data identify a specific suppressive macrophage population induced by a single parasite immunomodulator, which protects against mucosal inflammation.

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The Jovian moon, Europa, hosts a thin neutral gas atmosphere, which is tightly coupled to Jupiter's magnetosphere. Magnetospheric ions impacting the surface sputter off neutral atoms, which, upon ionization, carry currents that modify the magnetic field around the moon. The magnetic field in the plasma is also affected by Europa's induced magnetic field. In this paper we investigate the environment of Europa using our multifluid MHD model and focus on the effects introduced by both the magnetospheric and the pickup ion populations. The model self-consistently derives the electron temperature that governs the electron impact ionization process, which is the major source of ionization in this environment. The resulting magnetic field is compared to measurements performed by the Galileo magnetometer, the bulk properties of the modeled thermal plasma population is compared to the Galileo Plasma Subsystem observations, and the modeled surface precipitation fluxes are compared to Galileo Ultraviolet Spectrometer observations. The model shows good agreement with the measured magnetic field and reproduces the basic features of the plasma interaction observed at the moon for both the E4 and the E26 flybys of the Galileo spacecraft. The simulation also produces perturbations asymmetric about the flow direction that account for observed asymmetries.