Papers by Christian Nielsen
Journal of Materials Chemistry C, 2019
In this review, we provide an overview of conjugated organic semiconductors and their application... more In this review, we provide an overview of conjugated organic semiconductors and their applications in biological sensing with a primary focus on the role of the organic semiconductor. We cover work carried out with polymers as well as small molecules, from the well-established and commercially available systems to the emerging and recently developed materials.
Research Square (Research Square), May 11, 2023
Despite the growing interest in dynamic behaviors at the frequency domain, there exist very few s... more Despite the growing interest in dynamic behaviors at the frequency domain, there exist very few studies on molecular orientation-dependent transient responses of organic mixed ionic-electronic conductors. In this research, we investigated the effect of ion injection directionality on transient electrochemical transistor behaviors by developing a model mixed conductor system. Two polymers with similar electrical, ionic, and electrochemical characteristics but distinct molecular orientations were successfully synthesized by varying the co-monomer unit (2,2'-bithiophene or phenylene) in conjunction with a novel 1,4-dithienylphenylene-based monomer. The comprehensive electrochemical analysis suggests that the molecular orientation affects the length of the ion-drift pathway, which is directly correlated with ion mobility, resulting in peculiar OECT transient responses. These results provide the general insight into molecular orientation-dependent ion movement characteristics as well as high-performance device design principles with ne-tuned transient responses.
arXiv (Cornell University), Oct 21, 2019
In the majority of molecular optimization tasks, predictive machine learning (ML) models are limi... more In the majority of molecular optimization tasks, predictive machine learning (ML) models are limited due to the unavailability and cost of generating big experimental datasets on the specific task. To circumvent this limitation, ML models are trained on big theoretical datasets or experimental indicators of molecular suitability that are either publicly available or inexpensive to acquire. These approaches produce a set of candidate molecules which have to be ranked using limited experimental data or expert knowledge. Under the assumption that structure is related to functionality, here we use a molecular fragment-based graphical autoencoder to generate unique structural fingerprints to efficiently search through the candidate set. We demonstrate that fragment-based graphical autoencoding reduces the error in predicting physical characteristics such as the solubility and partition coefficient in the small data regime compared to other extended circular fingerprints and string based approaches. We further demonstrate that this approach is capable of providing insight into real world molecular optimization problems, such as searching for stabilization additives in organic semiconductors by accurately predicting 92% of test molecules given 69 training examples. This task is a model example of black box molecular optimization as there is minimal theoretical and experimental knowledge to accurately predict the suitability of the additives.
American Journal of Physiology-endocrinology and Metabolism, Jun 1, 2020
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Cell Cycle, Sep 20, 2016
PICH is an SNF2-family DNA translocase that appears to play a role specifically in mitosis. Chara... more PICH is an SNF2-family DNA translocase that appears to play a role specifically in mitosis. Characterization of PICH in human cells led to the initial discovery of "ultra-fine DNA bridges" (UFBs) that connect the 2 segregating DNA masses in the anaphase of mitosis. These bridge structures, which arise from specific regions of the genome, are a normal feature of anaphase but had escaped detection previously because they do not stain with commonly used DNA dyes. Nevertheless, UFBs are important for genome maintenance because defects in UFB resolution can lead to cytokinesis failure. We reported recently that PICH stimulates the unlinking (decatenation) of entangled DNA by Topoisomerase IIa (Topo IIa), and is important for the resolution of UFBs. We also demonstrated that PICH and Topo IIa co-localize at the rDNA (rDNA). In this Extra View article, we discuss the mitotic roles of PICH and explore further the role of PICH in the timely segregation of the rDNA locus.
Frontiers in Cardiovascular Medicine
AimThe primary aim was to investigate the association between alarm acceptance compared to no-acc... more AimThe primary aim was to investigate the association between alarm acceptance compared to no-acceptance by volunteer responders, bystander intervention, and survival in out-of-hospital cardiac arrest.Materials and methodsThis retrospective observational study included all suspected out-of-hospital cardiac arrests (OHCAs) with activation of volunteer responders in the Capital Region of Denmark (1 November 2018 to 14 May 2019), the Central Denmark Region (1 November 2018 to 31 December 2020), and the Northern Denmark Region (14 February 2020 to 31 December 2020). All OHCAs unwitnessed by Emergency Medical Services (EMS) were analyzed on the basis on alarm acceptance and arrival before EMS. The primary outcomes were bystander cardio-pulmonary resuscitation (CPR), bystander defibrillation and secondary outcome was 30-day survival. A questionnaire sent to all volunteer responders was used with respect to their arrival status.ResultsWe identified 1,877 OHCAs with volunteer responder acti...
Satoyama Initiative Thematic Review, 2022
International awareness of the world-renowned Angkor Wat temple complex has drawn attention to th... more International awareness of the world-renowned Angkor Wat temple complex has drawn attention to the challenges of climate change, deforestation, and water management in Cambodia. The aim of this chapter is to examine the benefits of enhanced water management provided within Angkor Archaeological Park, and to consider challenges to maintaining those benefits. The Authority for the Protection of the Site and Management of the Region of Angkor (APSARA) designed and in 2014-2018 implemented within the Park a water management project to recharge groundwater supplies, mitigate floods, and provide irrigation. To assess the benefits, we draw on an economic analysis of ecosystem service changes, including interviewing 145 households from across the Park and four experts. To assess challenges to sustaining the benefits, we also interviewed 73 households and conducted 12 focus group discussions in the upper catchment. We used a combination of quantitative analysis (i.e. economic assessment) and qualitative data analysis (e.g. thematic analysis). Our analyses of data from people living in and around the Park showed that improved water management (e.g. reinforcing dykes and storage facilities for groundwater recharge) and investment in economic diversification (e.g. tourism, horticulture, and heritage crops projects) reduced vulnerability of the people to climate hazards. Currently, these benefits are threatened by forest loss in C. Jacobson (*) Live and Learn Environmental Education,
Molecular Nutrition & Food Research
ScopeReady‐to‐feed liquid infant formula is increasingly used for preterm infants when human milk... more ScopeReady‐to‐feed liquid infant formula is increasingly used for preterm infants when human milk is unavailable. These formulas are sterilized by ultra‐high temperature treatment, but heating and storage may reduce bioactivity and increase formation of Maillard reaction products with potential negative consequences for immature newborns.Methods and resultsUsing preterm pigs as a model for sensitive newborn infants, the study tests the intestinal responses of feeding experimental liquid formula within 5 days. A pasteurized formula (PAST) with the same nutrient composition but less protein modifications serves as control to ultra‐high temperature‐treated formula without (UHT) and with prolonged storage (SUHT). Relative to PAST, UHT contains lower levels of lactoferrin and IgG. Additional storage (40 °C, 60 days, SUHT) reduces antimicrobial capacity and increases non‐reducible protein aggregates and Maillard reaction products (up to 13‐fold). Pigs fed SUHT have more diarrhea and show ...
Welcome to the third issue of the Journal of Business Models. At the Journal of Business Models w... more Welcome to the third issue of the Journal of Business Models. At the Journal of Business Models we are happy to be receiving high quality submissions from the scientific community. We would also like to take this opportunity to thank our Editorial Advisory Board and Editorial Review Board for their great work. We strive to uphold the highest standards of academic rigour and are currently working on how to best communicate this to our academic audience in order to attract further high quality submissions. We believe the quality of the papers should speak for themselves, but we also realize that the message sometimes needs a push in the direction of the audience. Recently, the Journal of Business Models has been registered on the Directory of Open Access Journals (DOAJ) and in the coming period, academic listings and indexing will be pursued with great effort. If you have suggestions for relevant listings or indexing that would provide credibility to your own institution, please do not hesitate to contact us. gic management, organization and business planning. We welcome submissions relating to all sub-disciplines of business models. If you have suggestions for special issues or special themes, please do not hesitate to contact us. Also please contact us if you wish to join the Editorial Review Panel. At the 23rd Nordic Academy of Management conference to be held at Copenhagen Business School from August 12 to 14, 2015, track 11 will focus on the "Sustainability and Scalability of Business Models".
RMD Open, 2019
IntroductionStandardised scoring systems for rheumatoid arthritis (RA) joint disease activity inc... more IntroductionStandardised scoring systems for rheumatoid arthritis (RA) joint disease activity include Larsen score for radiographs, rheumatoid arthritis magnetic resonance imaging score (RAMRIS) for MRI and using the European League Against Rheumatisms-Outcome Measures in Rheumatology (EULAR-OMERACT) score for ultrasound (US) images. The aim of this prospective study was to investigate the relationship between histological synovitis and radiological synovitis, assessed by conventional X-ray, US and MRI of the wrist radiocarpal joint.Methods20 patients with treatment naive early RA (ERA) and 20 with long-standing RA (LRA) were enrolled in a 6-month prospective study. Patients with RA underwent US-guided synovial biopsy, X-ray and US of the wrist at enrolment and 6 months. MRI at baseline and also at 6 months for the ERA group, and scored with the RAMRIS system. X-ray was scored by Larsen score and US by the EULAR-OMERACT system. Synovial biopsy inflammation was determined by the Kren...
ChemPlusChem, 2019
We have designed and synthesised a series of copolymers containing a glycolated 1,4-dithienyl-2,3... more We have designed and synthesised a series of copolymers containing a glycolated 1,4-dithienyl-2,3,5,6-tetrafluorophenylene unit copolymerized with thiophene, bithiophene, thienothiophene and 1,2,4,5-tetrafluorobenzene comonomer units by direct heteroarylation polymerisation. We have investigated the optical, electrochemical, electrochromic and solid-state structural properties of the copolymers. The copolymers exhibit stable redox properties in organic solvents and promising redox properties in thin film configuration with an aqueous electrolyte. Finally, we have assessed the potential of the copolymers as active materials in organic electrochemical transistors (OECTs) finding promising performance as an accumulation mode OECT material with a peak transconductance of 0.17 mS and a good on/off ratio of 10 5 for the thiophene copolymer.
How spatial chromosome organization influences genome integrity is still poorly understood. Here ... more How spatial chromosome organization influences genome integrity is still poorly understood. Here we show that DNA double-strand breaks (DSBs) mediated by topoisomerase 2 (TOP2) activities, are enriched at chromatin loop anchors with high transcriptional activity. Recurrent DSBs occur at CTCF/cohesin bound sites at the bases of chromatin loops and their frequency positively correlates with transcriptional output and directionality. The physiological relevance of this preferential positioning is indicated by the finding that genes recurrently translocating to drive leukemias, are highly transcribed and are enriched at loop anchors. These genes accumulate DSBs at recurrent hot spots that give rise to chromosomal fusions relying on the activity of both TOP2 isoforms and on transcriptional elongation. We propose that transcription and 3D chromosome folding jointly pose a threat to genomic stability, and are key contributors to the occurrence of genome rearrangements that drive cancer.
ACS synthetic biology, Jan 21, 2017
Transcription factor-based biosensors are used to identify producer strains, a critical bottlenec... more Transcription factor-based biosensors are used to identify producer strains, a critical bottleneck in cell factory engineering. Here, we address two challenges with this methodology: transplantation of heterologous transcriptional regulators into new hosts to generate functional biosensors and biosensing of the extracellular product concentration that accurately reflects the effective cell factory production capacity. We describe the effects of different translation initiation rates on the dynamic range of a p-coumaric acid biosensor based on the Bacillus subtilis transcriptional repressor PadR by varying its ribosomal binding site. Furthermore, we demonstrate the functionality of this p-coumaric acid biosensor in Escherichia coli and Corynebacterium glutamicum. Finally, we encapsulate yeast p-coumaric acid-producing cells with E. coli-biosensing cells in picoliter droplets and, in a microfluidic device, rapidly sort droplets containing yeast cells producing high amounts of extracel...
Cell cycle (Georgetown, Tex.), Jan 17, 2016
PICH is an SNF2-family DNA translocase that appears to play a role specifically in mitosis. Chara... more PICH is an SNF2-family DNA translocase that appears to play a role specifically in mitosis. Characterization of PICH in human cells led to the initial discovery of "ultra-fine DNA bridges" (UFBs) that connect the 2 segregating DNA masses in the anaphase of mitosis. These bridge structures, which arise from specific regions of the genome, are a normal feature of anaphase but had escaped detection previously because they do not stain with commonly used DNA dyes. Nevertheless, UFBs are important for genome maintenance because defects in UFB resolution can lead to cytokinesis failure. We reported recently that PICH stimulates the unlinking (decatenation) of entangled DNA by Topoisomerase IIα (Topo IIα), and is important for the resolution of UFBs. We also demonstrated that PICH and Topo IIα co-localize at the rDNA (rDNA). In this Extra View article, we discuss the mitotic roles of PICH and explore further the role of PICH in the timely segregation of the rDNA locus.
Developmental cell, Jun 20, 2016
Steroid hormones control important developmental processes and are linked to many diseases. To sy... more Steroid hormones control important developmental processes and are linked to many diseases. To systematically identify genes and pathways required for steroid production, we performed a Drosophila genome-wide in vivo RNAi screen and identified 1,906 genes with potential roles in steroidogenesis and developmental timing. Here, we use our screen as a resource to identify mechanisms regulating intracellular levels of cholesterol, a substrate for steroidogenesis. We identify a conserved fatty acid elongase that underlies a mechanism that adjusts cholesterol trafficking and steroidogenesis with nutrition and developmental programs. In addition, we demonstrate the existence of an autophagosomal cholesterol mobilization mechanism and show that activation of this system rescues Niemann-Pick type C1 deficiency that causes a disorder characterized by cholesterol accumulation. These cholesterol-trafficking mechanisms are regulated by TOR and feedback signaling that couples steroidogenesis with...
Using UK data for the period 1997:3 to 2005:5, this paper examines whether the expectations hypot... more Using UK data for the period 1997:3 to 2005:5, this paper examines whether the expectations hypothesis is supported by recent UK data when the short-end of the term structure of interest rates is considered and whether the results of the tests of the expectations hypothesis are sensitive to the choice of data. The main results can be nicely summarized by considering …ve virtual researchers who test the expectations hypothesis using …ve di¤erent data sets for the 1997:3 to 2005:5 period for the 1 to 12-month maturity spectrum and who get quite di¤erent results. The main conclusion to be drawn from the analysis in this paper is thus that robustness check may be very important when testing the expectations hypothesis using the 1 to 12-month maturity spectrum of the term structure. Furthermore, the results suggest that the speci…c data set used in tests of the expectations hypothesis may be a candidate explanation of a rejection of the expectations hypothesis -along with the possibility that a time-varying term premium and/or a structural break are responsible for the rejection.
SSRN Electronic Journal, 2015
In this paper we extract the factors that shape the yield curve and we relate them with macroecon... more In this paper we extract the factors that shape the yield curve and we relate them with macroeconomy. We examine whether the term structure can predict future economic activity by applying a range of econometric approaches both in pre-and post-crisis periods. Furthermore, we assess the strength of the yield curve forecasting power on economic activity for Eurozone. In addition, we analyze the effect of increased market risk in the term structure and economic activity whereas we evaluate the impact of monetary policy in the term structure. We find that the forecasting performance of term structure deteriorates in the postcrisis period and that credit spreads forecast better Eurozone industrial production. Also, as we find, one significant explanation for the change in predictability during pre-and postcrisis periods is due to the effect of market risk on the term structure during the post-crisis period. Finally, we argue that monetary policy determines significantly the term structure either by conventional or unconventional measures.
Journal of health care finance, 2010
This study focuses on how financial analysts understand the strategy of a health care company and... more This study focuses on how financial analysts understand the strategy of a health care company and which elements, from such a strategy perspective, they perceive as constituting the cornerstone of a health care company's business model. The empirical part of this study is based on semi-structured interviews with analysts following a large health care company listed on the Copenhagen Stock Exchange. The authors analyse how the financial analysts view strategy and value creation within the framework of a business model. Further, the authors analyze whether the characteristics emerging from a comprehensive literature review are reflected in the financial analysts' perceptions of which information is decision-relevant and important to communicate to the financial markets. Among the conclusions of the study is the importance of distinguishing between the health care companies' business model and the model by which the payment of revenues are allocated between end users and re...
New public management is concerned with the transformation of public sector by introducing new de... more New public management is concerned with the transformation of public sector by introducing new demands such as the accountability of managers, quality of the supplied services and efficiency in the use of taxpayers' money. An important part of new public management agenda is therefore concerned with introducing new management accounting methods, termed management accounting innovations. While most related studies tend to focus on the attributes leading to good implementation and adoption of such management technologies, the questions here concern whether these innovations, primarily derived from the private sector, also are applicable and used to the public sector domain. Through a questionnaire survey based on 290 respondents, this paper enlightens our knowledge of the adoption of general management accounting practices, cost assignment practices, measures of user service, benchmarking and measures of projects. This analysis is conducted through the use of regression analysis, factor analysis and supplementary descriptive statistics. Finally, correlation is employed to illustrate the structures between key variables. The results show that the degree of knowledge concerning new management accounting innovations (ABC, BSC, Intellectual capital, TQM etc.) are fairly differentiated and there indeed is a positive association between the key variables such. Besides, several comments from the respondents show that the adoptions of now accounting innovations are increasing.
Uploads
Papers by Christian Nielsen