Structural Assessment of the Glulam Arches at Stockholm Central Station

The purpose of this master’s thesis was to investigate if suspension of heavy objectsis possible in the glulam arches at Stockholm Central Station. The main goal was todetermine the arches’ load carrying capacity’s utility ratio, in order to give knowledgeif additional loading can be added.The study included a thorough investigation of available blueprints and calculationreports established during and after the process of design and erection of the arches.In addition, an on-site-inventory was made to confirm and verify the studied material.A method to approximate semi-probabilistic material strength-properties, based onold deterministic material strength properties, was used.When the material had been summarized concluding geometrical attributes, loads, andmaterial properties a calculation model of the arch was developed. The global geometrydescribing the arch’s shape mathematically was established through measures onblueprints and analytical calculations in Mathcad. A finite element method (FEM) wasthen used to calculate reaction- and internal forces and buckling modes taking accountfor 2nd order effects. Once calculation of intrenal forces had been made, the structuralcapacity was checked analytically according to Eurocode’s failure criterion.The results showed that the arches do not fulfill required carrying capacity forEurocode’s symmetric- and non-symmetric distributed snow load. The failurecriterion not fulfilled were simultaneously bending and compression, lateral torsionalbuckling and simultaneously tension perpendicular to grain and shear.It is therefore concluded that suspension of heavy objects is not suitable with thepresent condition of the arch. In order to realize suspension, it is suggested thatreinforcement measures have to be conducted. It is also suggested that shear andiiiflexural carbon fiber reinforced polymer (CFRP) reinforcement would be a suitablemethod of enhancing the strength and stiffness of the arches, without disrupting theiraesthetics and integrity

Tardy development of safe medicines for children : a Nordic network offers new platform to reduce this inequity

Non peer reviewe

Improved infrastructure and support needed for paediatric clinical trials in Sweden

Aim: There is a lack of authorised medicines for paediatric patients and improved drug development is necessary. The aim of this study was to evaluate the need for infrastructure and support for paediatric clinical trials in Sweden. Methods: A web-based survey was sent to doctors and nurses involved in the care of neonates, children and adolescents assessing the current situation and future needs for paediatric clinical trials in Sweden. Questions regarding premises, competence, organisation, support for paediatric clinical trials and Good Clinical Practice Training were addressed. Results: In total, 137 individuals responded to the survey (109 doctors and 28 nurses). Overall, 61% of the respondents had previous experience of paediatric clinical trials. Some respondents had access to trial units, but only 34% had used the trial unit for support. Half of the responders were interested in recurrent paediatric Good Clinical Practice training. Doctors responded that clinical work often had to be prioritised and emphasised the need for research time. Conclusion: This study clearly shows the commitment for clinical trials among doctors and nurses involved in paediatric care in Sweden, but also that administrative, logistic and economic support in a sustainable setting and an expanded national collaboration are needed

High Brain Tissue Oxygen Tension during Ventilation with 100% Oxygen after Fetal Asphyxia in Newborn Sheep.

The optimal FiO2 for newborn resuscitation is still not settled. We hypothesized that short-lasting oxygen ventilation after intrauterine asphyxia would not cause arterial or cerebral hyperoxia, and therefore be innocuous. The umbilical cord of fetal sheep was clamped and 10 min later, after delivery, ventilation with air (n=7) or with 100% oxygen for 3 (n=6) or 30 min (n=5), followed by air, was started. Among the eleven lambs given 100% O2, oxygen tension (PO2) was 10.7 (1.8 - 56) kPa [median (range)] in arterial samples taken after 2.5 min of ventilation. In those ventilated with 100% oxygen for 30 min, brain tissue PO2 (PbtO2) increased from less than 0.1 kPa in each lamb to individual maxima of 56 (30-61) kPa, while in those given oxygenfor just 3 min, PbtO2peaked at 4.2 (2.9 - 46) kPa. The maximal PbtO2 in air-ventilated lambs was 2.9 (0.8-5.4) kPa. Heart rate and blood pressure increased equally fast in the three groups. Thus, prolonged ventilation with 100% oxygen caused an increase in PbtO2of a magnitude previously only reported under hyperbaric conditions. Reducing the time of 100% oxygen ventilation to 3 min did not consistently avert systemic hyperoxia

Early impact of severe acute respiratory syndrome coronavirus 2 on pediatric clinical research : a Pan-European and Canadian snapshot in time

Objective To capture the early effects of the coronavirus disease 2019 (COVID-19) pandemic on pediatric clinical research. Study design Pediatric clinical research networks from 20 countries and 50 of their affiliated research sites completed two surveys over one month from early May to early June 2020. Networks liaised with their affiliated sites and contributed to the interpretation of results through pan-European group discussions. Based on first detection dates of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), countries formed 1 early detecting and 1 late detecting cluster. We tested the hypothesis that this clustering influenced clinical research. Results Research sites were first impacted by the pandemic in mid-March 2020 (March 16 +/- 10 days, the same date as lockdown initiation; P = .99). From first impact up until early June, site initiation and feasibility analysis processes were affected for >50% of the sites. Staff were redirected to COVID-19 research for 44% of the sites, and 75.5% of sites were involved in pediatric COVID-19 research (only 6.3% reported COVID-19 cases in their other pediatric trials). Mitigation strategies were used differently between the early and late detecting country clusters and between countries with and without a pediatric COVID-19 research taskforce. Positive effects include the development of teleworking capacities. Conclusions Through this collaborative effort from pediatric research networks, we found that pediatric trials were affected and conducted with a range of unequally applied mitigations across countries during the pandemic. The global impact might be greater than captured. In a context where clinical research is increasingly multinational, this report reveals the importance of collaboration between national networks