18 research outputs found
Ionic and electronic dark decay of holograms in LiNbO3:Fe crystals
The lifetimes of nonfixed holograms in LiNbO3:Fe crystals with doping levels of 0.05, 0.138, and 0.25 wt % Fe2O3 have been measured in the temperature range from 30 to 180 °C. The time constants of the dark decay of holograms stored in crystals with doping levels of 0.05 and 0.25 wt % Fe2O3 obey an Arrhenius-type dependence on absolute temperature T, but yield two activation energies: 1.0 and 0.28 eV, respectively. For these crystals, two different dark decay mechanisms are prevailing, one of which is identified as proton compensation and the other is due to electron tunneling between sites of Fe2 + and Fe3 + . The dark decay of holograms stored in crystals with the doping level of 0.138 wt % Fe2O3 is the result of a combination of both effects
Mild therapeutic hypothermia alters neuron specific enolase as an outcome predictor after resuscitation: 97 prospective hypothermia patients compared to 133 historical non-hypothermia patients
Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19
IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19.
Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19.
DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022).
INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days.
MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes.
RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively).
CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes.
TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570
The Idea Maturity Model - A Dynamic Approach to Evaluate Idea Maturity
In idea creation and assessment processes the accruement and the description of an idea are mostly allocated to a fixed point in time, defined as the end of the generating process and the start of the idea assessment. This static approach does not fit the reality in industrial idea processes. A dynamic approach for idea assessment is therefore introduced. An idea is not seen as a static but as a dynamic state, characterized by different degrees of maturity. Maturity is understood as a measure of the assessability of the individual evaluation characteristics.
Based on Crosby’s maturity model and on classical Capability Maturity Models, a new Idea Maturity Model (IMM) has been developed and is introduced for the first time. The five Idea Maturity Levels (IML) are named Initial, Awareness, Appraisability, Valuation, and Realisability and harmonize well with other maturity models. The levels are described by general characteristics, although the development of the maturity model focussed on new product or service development. The compatibility of the IMM with idea assessment processes and conditions in organisations and companies has been checked
The Idea Maturity Model - A Dynamic Approach to Evaluate Idea Maturity
In idea creation and assessment processes the accruement and the description of an idea are mostly allocated to a fixed point in time, defined as the end of the generating process and the start of the idea assessment. This static approach does not fit the reality in industrial idea processes. A dynamic approach for idea assessment is therefore introduced. An idea is not seen as a static but as a dynamic state, characterized by different degrees of maturity. Maturity is understood as a measure of the assessability of the individual evaluation characteristics.
Based on Crosby’s maturity model and on classical Capability Maturity Models, a new Idea Maturity Model (IMM) has been developed and is introduced for the first time. The five Idea Maturity Levels (IML) are named Initial, Awareness, Appraisability, Valuation, and Realisability and harmonize well with other maturity models. The levels are described by general characteristics, although the development of the maturity model focussed on new product or service development. The compatibility of the IMM with idea assessment processes and conditions in organisations and companies has been checked
Safety of the transport of children on bicycles and in bicycle trailers
Wegen der wachsenden Verbreitung von Fahrradanhängern zum Kindertransport und der möglichen Unfallgefährdung ist im vorliegenden Forschungsprojekt deren passive Sicherheit untersucht worden. Zudem wurde der Frage nachgegangen, ob der Transport von Kindern im Fahrradanhänger sicherer ist als mit dem Fahrrad mit Kindersitzen. In Absprache mit Herstellern und Vertreibern wurden verschiedene Untersuchungen durchgeführt. Es handelte sich um Anprallversuche (Anfahrversuche), Rollwagenversuche (Schlittenversuche) sowie Kopffreiheitsprüfungen und Fallversuche. Bei den Versuchen waren die Prüfobjekte mit einem oder zwei Dummies besetzt, die mit Messdatenaufnehmern ausgestattet waren. Verschiedene Messdaten, zum Beispiel Kopf- und Brustbeschleunigung, wurden erfasst und ausgewertet. Zusätzlich wurde das Kopfschutzkriterium (HPC) berechnet und bewertet. Entstandene Schäden an den Prüfobjekten wurden aufgenommen und durch Fotos dokumentiert. Die Versuchsabläufe selbst wurden mit Hochgeschwindigkeitskameras aus verschiedenen Positionen aufgezeichnet. Beim Anfahrversuch mit einem Pkw gegen ein Gespann aus Fahrrad und Anhänger waren direkte Anstöße der Anhängerinsassen an die Pkw-Front zu erkennen. Die Beschleunigungswerte waren dabei relativ hoch. Anstöße gegen Anhängerinnenteile waren bei fast allen Versuchen zu beobachten. Teilweise wurden Radaufhängungen und Radnaben beschädigt. Durch die Rollwagenversuche wurden konstruktive Schwächen bei den Sitzen und Rückhaltesystemen festgestellt. Nähte, Befestigungen und Verstellösen wurden zerstört. Es stellte sich heraus, dass die Qualität des Gurtsystems, die Steifigkeit des Anhängeraufbaus, die Sitzposition der Kinder und die vorhandene Kopffreiheit ausschlaggebend für das Verletzungsrisiko der Insassen sind. Bei den Versuchen mit Fahrradsitzen ergaben sich hohe Beschleunigungswerte durch den direkten Kontakt des Radfahrers mit der Fahrzeugfront und/oder der Fahrbahn. Das Gewicht des Radfahrers, des Fahrrades und auch Fahrradteile bergen ein erhöhtes Verletzungsrisiko für das Kind. Zusätzlich besteht die Gefahr überfahren zu werden, wenn das Kind nach dem Sturz des Fahrrades ungeschützt auf der Fahrbahn liegt. Ein direkter Vergleich der beiden Transportmöglichkeiten war aufgrund der geringen Daten der Versuche mit Fahrradkindersitzen nur bedingt möglich. Tendenziell ist der Transport der Kinder im Fahrradanhänger als weniger gefährlich zu bewerten. Es werden die Vor- und Nachteile dargestellt. Zur Bewertung der Sicherheit von Fahrradanhängern wurden die folgenden Prüfmethoden erarbeitet: - Pendelschlagprüfung für die gesamte Chassisstruktur; - Kopffreiheitsprüfung; - Belastungsprüfung der Aufbaustruktur; - Festigkeitsprüfung der Gurtsysteme. Die Prüfungen sind so aufgebaut, dass sie mit einfachen Mitteln durchzuführen sind. Es sollte somit jedem Anhängerhersteller möglich sein, die passive Sicherheit seiner Produkte umfassend zu untersuchen. Die Prüfverfahren für die Sicherheitsbewertung sollen in eine DIN-Norm und in das Merkblatt für Fahrradanhänger einfließen. Der Original-Forschungsbericht enthält einen umfangreichen Fotoband zu den Einzelheiten der Versuche und Versuchsaufbauten sowie zu den Beschädigungen der Prüfobjekte und kann bei der BASt eingesehen werden.In view of the growing use of bicycle trailers for the transport of children and the possible danger through accidents, this research project investigated the passive safety of such trailers. The question was also considered as to whether the transport of children in bicycle trailers is safer than on bicycles equipped with child safety seats. In consultation with manufacturers and distributors various investigations were carried out. These included crash tests (starting tests), trolley tests (sled tests), headroom tests and drop tests. For the tests the test objects were Ioaded with one or two dummies which were equipped with measuring data sensors. Various measuring data were recorded and evaluated, e.g. head and chest acceleration. The head protection criterion (HPC) was also calculated and evaluated. Damage which occurred to the test objects was recorded and documented by means of photographs. The test sequences themselves were recorded from different positions using high-speed cameras. In the starting tests, involving a car colliding with a bicycle-trailer combination, the trailer occupants were seen to come into direct contact with the car front. The acceleration values were relatively high. In almost all cases there were collisions with internal parts of the trailers. In some cases the chassis and wheel hubs were damaged. Design weaknesses in the seats and restraint systems were established in the trolley tests. Stitching, attachments and adjusting loops were destroyed. lt was seen that the quality of the belt system, the stiffness of the trailer structure, the sitting position of the children and the amount of headroom were decisive for the risk of injury to the occupants. In the tests with bicycle seats the direct contact of the cyclist with the front of the car and/or the roadway produced high acceleration values. The weight of the cyclist and of the bicycle and also bicycle parts present an increased risk for the child. The danger also exists that the child can be run over if it lies unprotected on the roadway alter the collision of the bicycle. A direct comparison of both transport options was only possible to a limited degree on account of the small amount of data on the tests involving child safety seats for bicycles. Transporting children in bicycle trailers would seem to be less dangerous. The advantages and disadvantages have been presented. The following test methods were drawn up to evaluated the safety of bicycle trailers: - pendulum impact test for the whole chassis. - headroom test. - Ioad test for the structure of the trailer. - strength test for the belt systems. The tests are structured so that they can be carried out with simple equipment. lt should therefore be possible for every trailer manufacturer to comprehensively test the passive safety of his products. The test procedures for the safety evaluation are to be adopted in a DIN Standard and in the Guidelines for Bicycle Trailers. The research report contains in the original a comprehensive appendix (test descriptions, diagrams, tables, Guidelines for Bicycle Trailers, photos of the test objects, equipment, structures and damage caused) which has not been included here but which can be consulted at BASt. The appendix references have been retained in the publication for this purpose