Models of venous return and their application to estimate the mean systemic filling pressure

Mean systemic filling pressure is the equilibrium pressure in the systemic circulation when the heart is arrested and there is no flow. This pressure is a measure of the stressed volume of the systemic circulation and regarded as the driving pressure for the venous return during steady states [1-3]. In this thesis the terms stationary level and steady state refer to a state in which the mean pressure and flow, averaged over a heart cycle, do not change. Dynamic conditions refer to changes in averaged pressure and flow between heart beats. The property of mean systemic filling pressure as driving pressure fat venous return has been explained by Guyton [1] and others [2,3]. Most methods that are used to determine mean systemic filling pressure require a total stop of the circulation by inflating a balloon in the right atrium [4] or arresting the heart by fibrillation [5-9]. In 1985 Versprille & Jansen developed a method to determine mean systemic filling pressure in the intact circulation [10]. Their method required seven different steady states of central venous pressure and cardiac output. The total procedure lasted approximately 45 min. If circulatory conditions are nor stable for such a time span, this method is not useful. A main purpose of the research described in this thesis was to develop faster methods to determine the mean systemic filling pressure in the intact circulation

Abundances of the elements in the solar system

A review of the abundances and condensation temperatures of the elements and their nuclides in the solar nebula and in chondritic meteorites. Abundances of the elements in some neighboring stars are also discussed.Comment: 42 pages, 11 tables, 8 figures, chapter, In Landolt- B\"ornstein, New Series, Vol. VI/4B, Chap. 4.4, J.E. Tr\"umper (ed.), Berlin, Heidelberg, New York: Springer-Verlag, p. 560-63

Solar System Abundances of the Elements

Representative abundances of the chemical elements for use as a solar abundance standard in astronomical and planetary studies are summarized. Updated abundance tables for solar system abundances based on meteorites and photospheric measurements are presented.Comment: 46 pages; 5 figures; 8 tables; In: Principles and Perspectives in Cosmochemistry.Lecture Notes of the Kodai School on 'Synthesis of Elements in Stars' held at Kodaikanal Observatory, India, April 29 - May 13, 2008 (Aruna Goswami and B. Eswar Reddy eds.) Astrophysics and Space Science Proceedings, Springer-Verlag Berlin Heidelberg, 2010, p. 379-417 (ISBN 978-3-642-10351-3), 201

Clopidogrel in noncarriers of CYP2C19 loss-of-function alleles versus ticagrelor in elderly patients with acute coronary syndrome: a pre-specified sub analysis from the POPular Genetics and POPular Age trials CYP2C19 alleles in elderly patients

Background: Patients with acute coronary syndrome (ACS) who are carrying CYP2C19 loss-of-function alleles derive less benefit from clopidogrel treatment. Despite this, in elderly patients, clopidogrel might be preferred over more potent P2Y12 inhibitors due to a lower bleeding risk. Whether CYP2C19 genotype-guided antiplatelet treatment in the elderly could be of benefit has not been studied specifically.Methods: Patients aged 70 years and older with known CYP2C19*2 and *3 genotype were identified from the POPular Genetics and POPular Age trials. Noncarriers of loss-of-function alleles treated with clopidogrel were compared to patients, irrespective of CYP2C19 genotype, treated with ticagrelor and to clopidogrel treated carriers of loss-of-function alleles. We assessed net clinical benefit (all-cause death, myocardial infarction, stroke and Platelet Inhibition and Patient Outcomes (PLATO) major bleeding), atherothrombotic outcomes (cardiovascular death, myocardial infarction, stroke) and bleeding outcomes (PLATO major and minor bleeding).Results: A total of 991 patients were assessed. There was no significant difference in net clinical benefit (17.2% vs. 15.1%, adjusted hazard ratio (adjHR) 1.05, 95% confidence interval (CI) 0.77-1.44), atherothrombotic outcomes (9.7% vs. 9.2%, adjHR 1.00, 95%CI 0.66-1.50), and bleeding outcomes (17.7% vs. 19.8%, adjHR 0.80, 95%CI 0.62-1.12) between clopidogrel in noncarriers of loss-of-function alleles and ticagrelor respectively.Conclusion: In ACS patients aged 70 years and older, there was no significant difference in net clinical benefit and atherothrombotic outcomes between noncarriers of a loss-of-function allele treated with clopidogrel and pa-tients treated with ticagrelor. The bleeding rate was numerically; though not statistically significant, lower in pa-tients using clopidogrel.(c) 2021 Published by Elsevier B.V.Cardiolog

Endometrial scratching in women with one failed IVF/ICSI cycle-outcomes of a randomised controlled trial (SCRaTCH)

STUDY QUESTION: Does endometrial scratching in women with one failed IVF/ICSI treatment affect the chance of a live birth of the subsequent fresh IVF/ICSI cycle? SUMMARY ANSWER: In this study, 4.6% more live births were observed in the scratch group, with a likely certainty range between -0.7% and +9.9%. WHAT IS KNOWN ALREADY: Since the first suggestion that endometrial scratching might improve embryo implantation during IVF/ICSI, many clinical trials have been conducted. However, due to limitations in sample size and study quality, it remains unclear whether endometrial scratching improves IVF/ICSI outcomes. STUDY DESIGN, SIZE, DURATION: The SCRaTCH trial was a non-blinded randomised controlled trial in women with one unsuccessful IVF/ICSI cycle and assessed whether a single endometrial scratch using an endometrial biopsy catheter would lead to a higher live birth rate after the subsequent IVF/ICSI treatment compared to no scratch. The study took place in 8 academic and 24 general hospitals. Participants were randomised between January 2016 and July 2018 by a web-based randomisation programme. Secondary outcomes included cumulative 12-month ongoing pregnancy leading to live birth rate. PARTICIPANTS/MATERIALS, SETTING, METHODS: Women with one previous failed IVF/ICSI treatment and planning a second fresh IVF/ICSI treatment were eligible. In total, 933 participants out of 1065 eligibles were included (participation rate 88%). MAIN RESULTS AND THE ROLE OF CHANCE: After the fresh transfer, 4.6% more live births were observed in the scratch compared to control group (110/465 versus 88/461, respectively, risk ratio (RR) 1.24 [95% CI 0.96-1.59]). These data are consistent with a true difference of between -0.7% and +9.9% (95% CI), indicating that while the largest proportion of the 95% CI is positive, scratchin

Systematic approach in protection and ergonomics testing personal protective equipment

In the area of personal protection against chemical and biological (CB) agents there is a strong focus on testing the materials against the relevant threats. The testing programs in this area are elaborate and are aimed to guarantee that the material protects according to specifications. This ensures that the protective clothing and respiratory protection that is out on the market consist of the best material for that purpose. However, protective clothing and respiratory protective devices in practice are worn as a system that is a 3D structure that is subject to different environmental conditions, movement and mechanical tear and wear. In the last few years test methods at system level (Whole System Tests [WST] or Battlefield Protection factor), have been developed to address these issues and provide information on the protective performance of clothing and gasmasks, in addition to the protection of the materials. These tests provide crucial insight in the design of protective equipment and its effect on overall protection to the wearer. Ergonomics testing of CB protective equipment has always been performed separately from the protection tests. Most recent developments are aimed at integrating ergonomics type tests in to WST protection to be able to evaluate the protective performance of CB protective equipment and respiratory protection in operational environments. In this development the WSTs should reflect relevant practical working conditions and possibly should extend to actual measurement of protection at the working place. In this presentation the developments and challenges on these types of tests will be addressed. Furthermore, developments in other areas of protection, as they relate to testing in operational environments, will be discussed. These developments indidcate the trend that test methods should reflect operational environments and provide insight in protection under those circumstances. Similar trends can be observed in protection against CBRN, heat and flame, impact and detection. For personnel from military and First Responders organizations the combinations of all the protection types are also relevant. A systemic approach in developing sepcifications and corresponding test methods should allow to optimize their personal protective systems