Implementering af forelæsninger som hjælp til laboratorieøvelse på første års kemikursus

Denne rapport er afslutningen på KNUD projektet, der er en del af Universitetspædagogikum ved Københavns Universitet 2013-14. Brugen af laboratorieøvelser som en del af kemiundervisningen på universitetet har været en integreret del af undervisningen siden begyndelsen af 1800-tallet (Elliott et al. 2008). Rapport beskriver mine tanker og erfaringer under og efteropbygningen og implementeringen af ”labforelæsninger” som en støtte forud for laboratorieøvelser på et første års kemikursus. Dette er gjort for at fremme de studerendes udbytte af tiden de bruger i laboratoriet. Laboratorieøvelser som en del af et kursus er tungt både undervisningsmæssigt men også økonomisk. Derfor er det nødvendigt at se på om skrukturen af laboratorieøvelserne kan optimeres således det faglige udbyttet (kemisk forståelse) blandt de studerende kan øges - og som en sekundær ting om flere kan bestå eksamen via den øgede forståelse for faget

Evolution of Harmonic Distortion in a Cablified Grid Island after Separation from the Meshed Transmission Grid - A Case Study from Denmark

Green transition in Denmark with more renewable energy production and electrification of consumption, transport, heating, energy conversion and storage accelerates expansion and reconstruction of the transmission grid. When electricity generation and consumption have common connection cables and substations in the transmission grid, such centres are called prosumers.The prosumers do not necessarily increase the net energy exchange with the transmission grid but their short-circuit current contribution may significantly increase due to utilization of inverter-based units. To keep the short-circuit current contribution below the required rating, the meshed 150 kV transmission grid will be separated into islands that are interconnected through the 400 kV meshed transmission system. At the same time, 150 kV overhead lines will be replaced with underground cables as part of the ongoing grid reconstruction in Denmark. This paper presents the simulation results of the 5th harmonic voltage distortion evolution from the present grid stage with the meshed 150 kV transmission grid and, mainly, with overhead lines, through a long-term grid development process with cabling and separation of the meshed grid into 150 kV grid islands. The paper explains foreseen changes of the 5th harmonic voltage distortion within a specific grid island using a measurement validated simulation model for harmonic assessment and benchmarking the simulation results to the harmonic voltage measurements in the present grid stage. The paper also demonstrates identification and usage of early warnings for not-yet-occurred critical increases of the harmonic voltage distortion and proposal of mitigation solutions.<br/

High density Huh7.5 cell hollow fiber bioreactor culture for high-yield production of hepatitis C virus and studies of antivirals

Abstract Chronic hepatitis C virus (HCV) infection poses a serious global public health burden. Despite the recent development of effective treatments there is a large unmet need for a prophylactic vaccine. Further, antiviral resistance might compromise treatment efficiency in the future. HCV cell culture systems are typically based on Huh7 and derived hepatoma cell lines cultured in monolayers. However, efficient high cell density culture systems for high-yield HCV production and studies of antivirals are lacking. We established a system based on Huh7.5 cells cultured in a hollow fiber bioreactor in the presence or absence of bovine serum. Using an adapted chimeric genotype 5a virus, we achieved peak HCV infectivity and RNA titers of 7.6 log10 FFU/mL and 10.4 log10 IU/mL, respectively. Bioreactor derived HCV showed high genetic stability, as well as buoyant density, sensitivity to neutralizing antibodies AR3A and AR4A, and dependency on HCV co-receptors CD81 and SR-BI comparable to that of HCV produced in monolayer cell cultures. Using the bioreactor platform, treatment with the NS5A inhibitor daclatasvir resulted in HCV escape mediated by the NS5A resistance substitution Y93H. In conclusion, we established an efficient high cell density HCV culture system with implications for studies of antivirals and vaccine development

A Novel Diagnostic Target in the Hepatitis C Virus Genome

Christian Drosten and colleagues develop, validate, and make openly available a prototype hepatitis C virus assay based on the conserved 3' X-tail element, with potential for clinical use in developing countries