566 research outputs found
Zur Bedeutung der subpartualen Asphyxie fĂŒr die Prognose spĂ€terer asphyxieassoziierter Erkrankungen und Behinderungen
Diese Studie soll den Zusammenhang zwischen einer subpartualen Aspyhxie und spÀter auftretenden asphyxieassoziierten Erkrankungen, bzw. Behinderungen untersuchen.
Es wurden hierzu die in der perinatolog. Untersuchung erfassten asphyxieassoziierten Parameter Apgar, CTG und Nabelschnurarterien-pH auf ihre Bedeutung fĂŒr in der Einschulungsuntersuchung dokumentierte asphyxieassoziierte Erkrankungen, bzw. Behinderungen, betrachtet.
Beim Apgar handelt es sich um einen recht eindeutig dokumentierbaren Wert, der allerdings in der Studie keine Signifikanzen in Bezug auf spÀter auftretende apsyhxieassoziierte Erkrankungen, bzw. Behinderungen, aufweiset.
Auch beim CTG lassen sich keine Signifikanzen erkennen - auffÀllig ist hier mit 35% die hÀufige Einstufung eines CTG als pathologisch.
Der Nabelschnurarterien-pH weist im Bezug auf asphyxieassoziierte Behinderungen einen deutlichen signifikanten Zusammenhang auf, der in einer zusÀtzlich erfolgten logistischen Regression auch noch aufgewertet wird.
Problem hierbei: Exposed cases treten sehr selten auf - i.B.a. den Nabelschnurarterien - pH nur im einstelligen Bereich.
Wichtigstes Nebenergebnis der Studie ist der signifikante Zusammenhang von Zigarettenkonsum der Schwangeren mit einer asphyxieassoziierten Behinderung
Zur Bedeutung der subpartualen Asphyxie fĂŒr die Prognose spĂ€terer asphyxieassoziierter Erkrankungen und Behinderungen
Diese Studie soll den Zusammenhang zwischen einer subpartualen Aspyhxie und spÀter auftretenden asphyxieassoziierten Erkrankungen, bzw. Behinderungen untersuchen.
Es wurden hierzu die in der perinatolog. Untersuchung erfassten asphyxieassoziierten Parameter Apgar, CTG und Nabelschnurarterien-pH auf ihre Bedeutung fĂŒr in der Einschulungsuntersuchung dokumentierte asphyxieassoziierte Erkrankungen, bzw. Behinderungen, betrachtet.
Beim Apgar handelt es sich um einen recht eindeutig dokumentierbaren Wert, der allerdings in der Studie keine Signifikanzen in Bezug auf spÀter auftretende apsyhxieassoziierte Erkrankungen, bzw. Behinderungen, aufweiset.
Auch beim CTG lassen sich keine Signifikanzen erkennen - auffÀllig ist hier mit 35% die hÀufige Einstufung eines CTG als pathologisch.
Der Nabelschnurarterien-pH weist im Bezug auf asphyxieassoziierte Behinderungen einen deutlichen signifikanten Zusammenhang auf, der in einer zusÀtzlich erfolgten logistischen Regression auch noch aufgewertet wird.
Problem hierbei: Exposed cases treten sehr selten auf - i.B.a. den Nabelschnurarterien - pH nur im einstelligen Bereich.
Wichtigstes Nebenergebnis der Studie ist der signifikante Zusammenhang von Zigarettenkonsum der Schwangeren mit einer asphyxieassoziierten Behinderung
Dynamic Analysis of the STARC-ABL Propulsion System
In the pursuit of Electrified Aircraft Propulsion (EAP), much of the attention is on the development of hybrid electric concept vehicles and their propulsion systems from a steady state performance perspective. While it is steady-state performance that largely determines the efficiency of civil air transports, engine operability and transient performance define constraints for the steady state design that impact efficiency and system viability. Neglecting dynamics and control technologies can result in an over-designed, sub optimal propulsion system or a concept that is not feasible. Thus, dynamic system studies were conducted on the propulsion system of the conceptual aircraft design known as the Single-aisle Turboelectric AiRCraft with Aft Boundary Layer propulsor (STARC-ABL). This paper describes the development of a controller to verify the baseline concept's feasibility from an operability perspective. Further, studies were conducted to identify excessive stability margin in the baseline design that could be traded for potential benefits in efficiency through an engine re design. This study revealed the potential to reduce the high pressure compressor (HPC) stall margin by 3%. Finally, a study was conducted to investigate the potential benefit of adding energy storage to the STARC-ABL concept that further improves operability and enables more gains in engine efficiency and performance. The energy storage provided an additional 0.5% stall margin can be removed from the HPC
Turbine Electrified Energy Management (TEEM) For Enabling More Efficient Engine Designs
NASA is investing in Electrified Aircraft Propulsion (EAP) research as part of an effort to assist industry in meeting the future needs of a global aviation market. The integration of electric machines into traditional turbine-based propulsion provides opportunities to change system architectures effecting radical improvements in propulsive efficiency. However, less consideration has been afforded to the utilization of these electrical machines to improve the thermal efficiency and performance of the gas turbine engine. Noting this deficit, a novel operability concept is proposed and is referred to as Turbine Electrified Energy Management (TEEM). The concept is a transient control technology that supplements the main fuel control for the suppression of the natural off-design dynamics associated with changes in engine operating state. Here the electric machines, used as engine actuators during the transient, add or extract torque from the engine shafts to maintain the speed-flow characteristics of steady-state design operation. This greatly reduces the need to maintain transient stall margin stack in the compressors, among other potential benefits. This paper demonstrates the feasibility of the concept in dynamic simulation using a Numerical Propulsion System Simulation (NPSS) engine model of a NASA hybrid electric propulsion concept known as the Parallel Hybrid Electric Turbofan (hFan)
Water-Blown Polyurethane Foams Showing a Reversible Shape-Memory Effect
Water-blown polyurethane (PU) foams are of enormous technological interest as
they are widely applied in various fields, i.e., consumer goods, medicine,
automotive or aerospace industries. The discovery of the one-way shape-memory
effect in PU foams provided a fresh impetus for extensive investigations on
porous polymeric actuators over the past decades. High expansion ratios during
the shape-recovery are of special interest when big volume changes are
required, for example to fill an aneurysm during micro-invasive surgery or
save space during transportation. However, the need to program the foams
before each operation cycle could be a drawback impeding the entry of shape-
memory polymeric (SMP) foams to our daily life. Here, we showed that a
reversible shape-memory effect (rSME) is achievable for polyurethane water-
blown semicrystalline foams. We selected commercially available crystallizable
poly(Δ-caprolactone)-diols of different molecular weight for foams synthesis,
followed by investigations of morphology, thermal, thermomechanical and shape-
memory properties of obtained compositions. Densities of synthesized foams
varied from 110 to 180 kgâmâ3, while peak melting temperatures were
composition-dependent and changed from 36 to 47 °C, while the melting
temperature interval was around 15 K. All semicrystalline foams exhibited
excellent one-way SME with shape-fixity ratios slightly above 100% and shape-
recovery ratios from the second cycle of 99%. The composition with broad
distribution of molecular weights of poly(Δ-caprolactone)-diols exhibited an
rSME of about 12% upon cyclic heating and cooling from Tlow = 10 °C and Thigh
= 47 °C. We anticipate that our experimental study opens a field of systematic
investigation of rSMEs in porous polymeric materials on macro and micro scale
and extend the application of water-blown polyurethane foams to, e.g.,
protective covers with zero thermal expansion or even cushions adjustable to a
certain body shape. View Full-Tex
Thermal Modeling of an Advanced Geared Turbofan for Distributed Engine Control Application
Reliability and life-expectancy of gas turbine engine components is very much correlated to the temperature environment in which they operate. This is no different for control system components, especially those with electronic parts. In recent years, the concept of Distributed Engine Control (DEC) has emerged to address the limitations of the current centralized control implementation. This new approach involves relocating control system components from a relatively benign environment to the harsher thermal environment of the engine casing and its surrounding structures and cavities. In this paper, an approach to modeling the gas turbine thermal environment is described. The modeling approach is applied to a 3rd generation geared turbofan design with a focus on the engine locations where control instrumentation and actuation could be installed. The analysis was conducted with an eye toward component reliability and service life as it relates to the thermal environment. The results were found to be reasonable. Furthermore, the model is shown to execute in real-time within a multi-model simulation environment that demonstrates the capability to interact with hardware to drive test equipment
Ebola Virus Disease Outbreak in Isiro, Democratic Republic of the Congo, 2012: Signs and Symptoms, Management and Outcomes
Data collected during the 2012 Ebola virus disease (EVD) epidemic in the Democratic Republic of the Congo were analysed for clinical signs, symptoms and case fatality of EVD caused by Bundibugyo virus (BDBV), establishment of differential diagnoses, description of medical treatment and evaluation of the quality of clinical documentation. In a quantitative observational prospective study, global epidemiological data from 52 patients (34 patients within the community, 18 patients treated in the Ebola Treatment Centre) were entered anonymously into a database, subsequently matched and analysed. Relevant findings include an over-representation of females among community EVD cases (85.3%) and of community EVD cases in the age group of 15-54 years (82.4%). All ETC patients had fever (55.6% of all 18 ETC patients during their hospital stay) or self-reported fever (88.2% upon admission) at some point of time during their illness. Major symptoms of ETC patients during hospital stay included asthenia (82.4%), anorexia (82.4%), myalgia (70.6%), sore throat/difficulty swallowing (70.6%), arthralgia (76.5%) and nausea (70.6%). Gastrointestinal signs and symptoms (nausea, diarrhoea, vomiting) (76.4%) as well as general pain (94.1%) were frequent in ETC patients. The median duration of EVD was 18 days, while the mean incubation period was 11.3 days. Differential diagnosis of EVD included malaria (28.3%), intestinal parasitosis (10.9%), and infectious syndrome (10.9%). There was also an important variation in clinical evolvement. Quality of documentation was adversely affected by the way patient file contents were transferred from inside to outside the high-risk zone, entailing a mean mismatch value of 27.3% between patient file contents inside vs. outside the high-risk zone. This study adds further description of EVD (frequently non-specific signs and symptoms, non frequent bleeding, a long incubation period, long duration of disease) and emphasizes the need for improving clinical monitoring and documentation in EVD outbreak settings
Signs and Symptoms, Management and Outcomes
Data collected during the 2012 Ebola virus disease (EVD) epidemic in the
Democratic Republic of the Congo were analysed for clinical signs, symptoms
and case fatality of EVD caused by Bundibugyo virus (BDBV), establishment of
differential diagnoses, description of medical treatment and evaluation of the
quality of clinical documentation. In a quantitative observational prospective
study, global epidemiological data from 52 patients (34 patients within the
community, 18 patients treated in the Ebola Treatment Centre) were entered
anonymously into a database, subsequently matched and analysed. Relevant
findings include an over-representation of females among community EVD cases
(85.3%) and of community EVD cases in the age group of 15-54 years (82.4%).
All ETC patients had fever (55.6% of all 18 ETC patients during their hospital
stay) or self-reported fever (88.2% upon admission) at some point of time
during their illness. Major symptoms of ETC patients during hospital stay
included asthenia (82.4%), anorexia (82.4%), myalgia (70.6%), sore
throat/difficulty swallowing (70.6%), arthralgia (76.5%) and nausea (70.6%).
Gastrointestinal signs and symptoms (nausea, diarrhoea, vomiting) (76.4%) as
well as general pain (94.1%) were frequent in ETC patients. The median
duration of EVD was 18 days, while the mean incubation period was 11.3 days.
Differential diagnosis of EVD included malaria (28.3%), intestinal parasitosis
(10.9%), and infectious syndrome (10.9%). There was also an important
variation in clinical evolvement. Quality of documentation was adversely
affected by the way patient file contents were transferred from inside to
outside the high-risk zone, entailing a mean mismatch value of 27.3% between
patient file contents inside vs. outside the high-risk zone. This study adds
further description of EVD (frequently non-specific signs and symptoms, non
frequent bleeding, a long incubation period, long duration of disease) and
emphasizes the need for improving clinical monitoring and documentation in EVD
outbreak settings
High-sensitive nascent transcript sequencing reveals BRD4-specific control of widespread enhancer and target gene transcription
Gene transcription by RNA polymerase II (Pol II) is under control of promoters and distal regulatory elements known as enhancers. Enhancers are themselves transcribed by Pol II correlating with their activity. How enhancer transcription is regulated and coordinated with transcription at target genes has remained unclear. Here, we developed a high-sensitive native elongating transcript sequencing approach, called HiS-NET-seq, to provide an extended high-resolution view on transcription, especially at lowly transcribed regions such as enhancers. HiS-NET-seq uncovers new transcribed enhancers in human cells. A multi-omics analysis shows that genome-wide enhancer transcription depends on the BET family protein BRD4. Specifically, BRD4 co-localizes to enhancer and promoter-proximal gene regions, and is required for elongation activation at enhancers and their genes. BRD4 keeps a set of enhancers and genes in proximity through long-range contacts. From these studies BRD4 emerges as a general regulator of enhancer transcription that may link transcription at enhancers and genes
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