23 research outputs found

    Lignin Degradation Processes and the Purification of Valuable Products

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    Lignin is a heterogeneous, phenolic and polydisperse biopolymer which resists degradation due to its aromatic and highly branched structure. Lignin is the most abundant renewable source of aromatic molecules on earth. The valorization of lignin could therefore provide a sustainable alternative to petroleum refineries for the production of valuable aromatic compounds. Even so, paper mills and lignocellulose feedstock biorefineries treat lignin largely as a waste product. In paper mills, 98% of technical lignin is incinerated for internal energy recovery while only 2% is used commercially (e.g. for the production of aromatics such as vanillin). The reasons for the underutilization of lignin include its recalcitrance to degradation and the challenge of separating mixtures of numerous degradation products. The successful valorization of lignin in the future thus depends on a broad understanding of biological and technical degradation processes, and the implementation of efficient product purification strategies. This article describes enzymatic, photocatalytic and thermochemical lignin degradation processes and considers purification methods for valuable lignin-derived degradation products. We focus on the potential of membrane-based separation technology, including data from our own recent research

    (Re)-discovering simulation as a critical element of OM/SCM research : call for research

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    Purpose: This study focuses on (re-)introducing computer simulation as a part of the research paradigm. Simulation is a widely applied research method in supply chain and operations management. However, leading journals, such as the International Journal of Operations and Production Management, have often been reluctant to accept simulation studies. This study provides guidelines on how to conduct simulation research that advances theory, is relevant, and matters. Design/methodology/approach: This study pooled the viewpoints of the editorial team of the International Journal of Operations and Production Management and authors of simulation studies. The authors debated their views and outlined why simulation is important and what a compelling simulation should look like. Findings: There is an increasing importance of considering uncertainty, an increasing interest in dynamic phenomena, such as the transient response(s) to disruptions, and an increasing need to consider complementary outcomes, such as sustainability, which many researchers believe can be tackled by big data and modern analytical tools. But building, elaborating, and testing theory by purposeful experimentation is the strength of computer simulation. The authors therefore argue that simulation should play an important role in supply chain and operations management research, but for this, it also has to evolve away from simply generating and analyzing data. Four types of simulation research with much promise are outlined: empirical grounded simulation, simulation that establishes causality, simulation that supplements machine learning, artificial intelligence and analytics and simulation for sensitive environments. Originality/value: This study identifies reasons why simulation is important for understanding and responding to today's business and societal challenges, it provides some guidance on how to design good simulation studies in this context and it links simulation to empirical research and theory going beyond multimethod studies

    CpG-depleted promoters harbor tissue-specific transcription factor binding signalsā€”implications for motif overrepresentation analyses

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    Motif overrepresentation analysis of proximal promoters is a common approach to characterize the regulatory properties of co-expressed sets of genes. Here we show that these approaches perform well on mammalian CpG-depleted promoter sets that regulate expression in terminally differentiated tissues such as liver and heart. In contrast, CpG-rich promoters show very little overrepresentation signal, even when associated with genes that display highly constrained spatiotemporal expression. For instance, while āˆ¼50% of heart specific genes possess CpG-rich promoters we find that the frequently observed enrichment of MEF2-binding sites upstream of heart-specific genes is solely due to contributions from CpG-depleted promoters. Similar results are obtained for all sets of tissue-specific genes indicating that CpG-rich and CpG-depleted promoters differ fundamentally in their distribution of regulatory inputs around the transcription start site. In order not to dilute the respective transcription factor binding signals, the two promoter types should thus be treated as separate sets in any motif overrepresentation analysis

    NLO QCD+EW for V+jets

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    In this contribution recent results regarding the NLO electroweak corrections for vector boson production in association with jets are presented. Besides discussing the phenomenology of the fixed-order results, their incorporation in existing NLO QCD parton shower matched and merged calculations, which can directly be used in experimental analyses, will be shown

    STROKE-CARD care to prevent cardiovascular events and improve quality of life after acute ischaemic stroke or TIA: A randomised clinical trial.

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    Background Patients with ischaemic stroke or transient ischaemic attack (TIA) are at high risk of recurrent stroke and other cardiovascular diseases and commonly suffer from reduced quality of life. We aimed to determine whether the disease management programme STROKE-CARD can prevent cardiovascular diseases and improve quality of life in these patients. Methods In this pragmatic open-label two-centre randomised controlled trial with blinded outcome assessment, we randomly assigned patients with acute ischaemic stroke or TIA (ABCD2 score ā‰„3) in a 2:1 ratio to receive STROKE-CARD care or standard care. STROKE-CARD care is a disease management programme by a multidisciplinary stroke team that comprises a standardised 3-month visit and access to a web-based patient portal targeting risk factor management, post-stroke complications, comorbidities and cardiovascular warning signs, rehabilitation demands, and patient education, counselling, and self-empowerment. Co-primary outcomes were analysed on an intention-to-treat basis and were: (i) major cardiovascular disease events defined as nonfatal ischaemic or haemorrhagic stroke, nonfatal myocardial infarction, or vascular death occurring between hospital discharge and 12 months; and (ii) health-related quality of life at 12 months quantified with the EuroQol-5-Dimensions-3-Levels (EQ-5D-3L) overall utility score. This trial is registered with ClinicalTrials.gov, number NCT02156778. Findings Of 2149 patients enrolled between January 2014 and December 2017 (mean age 69 years, 41% female, 83% with ischaemic stroke, 17% with TIA), 1438 were assigned to STROKE-CARD care and 711 to standard care. Major cardiovascular disease events occurred in 78 patients in the STROKE-CARD care group (5.4%) and in 59 patients in the standard care group (8.3%) (hazard ratio, 0.63; 95% confidence interval: 0.45-0.88; P=0.007). STROKE-CARD care also led to a better EQ-5D-3L overall utility score at 12 months (P<0.001). Among pre-specified secondary outcomes, STROKE-CARD care improved all individual EQ-5D-3L dimensions and functional outcome on the modified Rankin Scale at 12 months. Post hoc explanatory analyses identified considerable demands for additional rehabilitation and refinement of preventive therapy regimes at the 3-month visit and high proportions of post-stroke complications and warning signs of imminent cardiovascular diseases within the first three months. Interpretation The pragmatic and easily implementable STROKE-CARD care programme reduced cardiovascular risk and improved health-related quality of life and functional outcome in patients with acute ischaemic stroke or TIA. Funding Tirol Kliniken, Tyrolean Health Insurance Company, Tyrol Health Care Funds, Boehringer Ingelheim, Nstim Services, Sanofi, Bayer Healthcare
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