High-pressure calorimetry: Thermophysical properties of gases and polymers

During the last decades polymers were important materials for technological progress of our western consumption society. The importance of advanced polymer materials is still increasing and polymers are not only used for packages anymore, but for high-value products such as high-voltage cable insulations, solar cell coatings or medical applications. Due to that, the necessity for optimized and energy efficient processes including a proper waste treatment is increasing. In 2015 worldwide plastic productions were at 322 million tons, mostly common polymers are Polypropylene (PP) and polyethylene (PE) with a content of 48.5%. [1] Some of the production processes, for example low-density polyethylene (LDPE), are performed at high pressures and temperatures of up to 3000 bar and 300 °C. To optimize respective processes, simulation-models have been used more commonly during the last years. Computational models are a comparatively cheap and safe alternative in comparison to actual changes in the process and can be used to test new concepts or recipes. Beside kinetics, simulation-models are based on thermophysical properties such as density or heat capacity. Correlations of these parameters are applied to describe the heat balance of the process and therefore influence the conversion during a simulation-run. To describe a process as detailed as possible, correlations of applied components like monomers or polymers have to rely on exact substance data. Although the temperature dependence of different properties is described well by currently applied correlations, a pressure dependence is mainly achieved by extrapolating fragmentary datasets. These data-sets were partly determined at atmospheric pressure and have not been evaluated further since their publication during the second half of the last century, which makes an application at the demanding polymerization process conditions rather imprecise.Consequently, for an improvement of such simulation-models new and exact substance data at the respective process conditions are required. In this work high-pressure calorimetry has been used for this purpose. Regular calorimetric devices, such as the DSC, have been applied to determine thermophysical properties at atmospheric pressure, but they are not suited for measurements at higher pressures. Such conditions require precise sensor technologies combined with rather massive mountings to withstand the extreme conditions. One device, which merges these properties is the transitiometer. This special Tian-Calvet calorimeter can withstand pressures up to 4000 bar without a decrease in precision. In a measurement one parameter (temperature, pressure or volume) is kept constant, the second one is varied with time and the third is measured as a function of the first two. Applying a pressure program in the transitiometer, expansion coefficients of different gases and polymers could be calculated when evaluating the measured difference heat fluxes. Coming from a temperature and pressure dependence of expansion coefficients, heat capacities could be determined in both dependencies as well. While testing different experimental setups, a pressure- and temperature dependence of densities of polymers could be calculated as well. In heat capacities of carbon dioxide, ethane or ethene a maximum in the temperature dependence in all measured pressures could be observed, which cannot be seen in methane or nitrogen. Beside a temperature-dependent maximum, a pressure dependent maximum is indicated in those molecules as well. Those maxima might be first experimental evidence of results regarding different molecular-dynamic simulations. Here, phenomena in the super-critical area of a phase diagram so called “Widom-Line” and/or “Frenkel-Line” that indicate a “pseudo” phase transition are predicted. That phenomena divide assumed homogeneous phase of the supercritical area, in a gas-like and a liquid-like region. [2] Next steps will be to validate measured data sets and to compare different types of polymers, including homo- and co-polymers. Additionally, it will be necessary to investigate not only pure substances such as polymers or gases, but to examine excess- and solubility effects between different molecules. First indications of such effects have already been observed since melting points of polymers change with pressure and different pressure media. Such effects might also influence already determined heat capacities or expansion coefficients. Another important task in the future will be the investigation of peroxide kinetics in dependence of pressure, temperature and solvent viscosity. [1] PlasticsEurope, 2016, http://www.plasticseurope.org/documents/document/20161014113313-plastics_the_facts_2016_final_version.pdf [2] T. Bryk and T. Scopigno, J. Phys. Chem. Lett., 2017, 8 (20), pp 4995–5001

Identifying Customer Values of B2C-Fintech Services in the Area of Personal Financial Management

Banks face the challenge of providing value that consumers are comfortable paying for. Although customer value is essential for fintech services, scant research exclusively focuses on technological advantages. This paper applies the theValue-Focused-Thinking approach to identify which values fintech services regarding personal financial management (PFM) can create for customers. Through 24 qualitative interviews, we identify 14 fundamental objectives and 15means objectives, which represent the potential customer values of PFM services(PFMS). The relationships of the identified objectives are illustrated in aMeans-Objective-Network. We prioritized the identified values through a quantitative online survey with 167 potential customers. The results provide insights into the characteristics that PFMSs should have to achieve the highest possible value for customers. Customers see PFMS as valuable if they deem the service trustworthy and give them control over their finances. This paper provides an early exploratory research contribution about the customer values of PFMSs

Limited utility of qPCR-based detection of tumor-specific circulating mRNAs in whole blood from clear cell renal cell carcinoma patients

BACKGROUND: RNA sequencing data is providing abundant information about the levels of dysregulation of genes in various tumors. These data, as well as data based on older microarray technologies have enabled the identification of many genes which are upregulated in clear cell renal cell carcinoma (ccRCC) compared to matched normal tissue. Here we use RNA sequencing data in order to construct a panel of highly overexpressed genes in ccRCC so as to evaluate their RNA levels in whole blood and determine any diagnostic potential of these levels for renal cell carcinoma patients. METHODS: A bioinformatics analysis with Python was performed using TCGA, GEO and other databases to identify genes which are upregulated in ccRCC while being absent in the blood of healthy individuals. Quantitative Real Time PCR (RT-qPCR) was subsequently used to measure the levels of candidate genes in whole blood (PAX gene) of 16 ccRCC patients versus 11 healthy individuals. PCR results were processed in qBase and GraphPadPrism and statistics was done with Mann-Whitney U test. RESULTS: While most analyzed genes were either undetectable or did not show any dysregulated expression, two genes, CDK18 and CCND1, were paradoxically downregulated in the blood of ccRCC patients compared to healthy controls. Furthermore, LOX showed a tendency towards upregulation in metastatic ccRCC samples compared to non-metastatic. CONCLUSIONS: This analysis illustrates the difficulty of detecting tumor regulated genes in blood and the possible influence of interference from expression in blood cells even for genes conditionally absent in normal blood. Testing in plasma samples indicated that tumor specific mRNAs were not detectable. While CDK18, CCND1 and LOX mRNAs might carry biomarker potential, this would require validation in an independent, larger patient cohort

Making Likelihood Ratios Digestible for Cross-Application Performance Assessment

Performance estimation is crucial to the assessment of novel algorithms and systems. In detection error tradeoff (DET) diagrams, discrimination performance is solely assessed targeting one application, where cross-application performance considers risks resulting from decisions, depending on application constraints. For the purpose of interchangeability of research results across different application constraints, we propose to augment DET curves by depicting systems regarding their support of security and convenience levels. Therefore, application policies are aggregated into levels based on verbal likelihood ratio scales, providing an easy to use concept for business-to-business communication to denote operative thresholds. We supply a reference implementation in Python, an exemplary performance assessment on synthetic score distributions, and a fine-tuning scheme for Bayes decision thresholds, when decision policies are bounded rather than fi

Morphing Attack Detection using Laplace operator based features

The vulnerability of facial recognition systems through morphing attacks is a known problem. Since the first publication about this vulnerability of facial recognition systems, a variety of morphing attack detection methods have been presented, promising an automated detection of such fraudulent attacks. In this work, a new approach is presented attempting to distinguish bona fide from morphed images based on information about the edges in the image extracted by the Laplace operator. It can be demonstrated that the features employed contain information that can contribute to the detection of morphed face images

Cooperative Effect of miR-141-3p and miR-145-5p in the Regulation of Targets in Clear Cell Renal Cell Carcinoma

Background Due to the poor prognosis for advanced renal cell carcinoma (RCC), there is an urgent need for new therapeutic targets and for prognostic markers to identify high risk tumors. MicroRNAs (miRNAs) are frequently dysregulated in tumors, play a crucial role during carcinogenesis and therefore might be promising new biomarkers. In previous studies, we identified miR-141-3p and miR-145-5p to be downregulated in clear cell RCC (ccRCC). Our objective was to investigate the functional association of these miRNAs, focusing on the cooperative regulation of new specific targets and their role in ccRCC progression. Methods The effect of miR-141-3p and miR-145-5p on cell migration was examined by overexpression in 786-O cells. New targets of both miRNAs were identified by miRWalk, validated in 786-O and ACHN cells and additionally characterized in ccRCC tissue on mRNA and protein level. Results In functional analysis, a tumor suppressive effect of miR-141-3p and miR-145-5p by decreasing migration and invasion of RCC cells could be shown. Furthermore, co-overexpression of the miRNAs seemed to result in an increased inhibition of cell migration. Both miRNAs were recognized as post-transcriptional regulators of the targets EAPP, HS6ST2, LOX, TGFB2 and VRK2. Additionally, they showed a cooperative effect again as demonstrated by a significantly increased inhibition of HS6ST2 and LOX expression after simultaneous overexpression of both miRNAs. In ccRCC tissue, LOX mRNA expression was strongly increased compared to normal tissue, allowing also to distinguish between non-metastatic and already metastasized primary tumors. Finally, in subsequent tissue microarray analysis LOX protein expression showed a prognostic relevance for the overall survival of ccRCC patients. Conclusion These results illustrate a jointly strengthening effect of the dysregulated miR-141-3p and miR-145-5p in various tumor associated processes. Focusing on the cooperative effect of miRNAs provides new opportunities for the development of therapeutic strategies and offers novel prognostic and diagnostic capabilities

Early Continence and Extravasation After Open Retropubic Radical Prostatectomy – Interrupted vs Continuous Suturing for Vesicourethral Anastomosis

Purpose: To compare running suture (RS) and interrupted suture (IS) of vesicourethral anastomosis (VUA) during open retropubic radical prostatectomy (RRP) on early urinary continence and extravasation. Patients and methods: Single center analysis of 211 patients who underwent RRP performed by a single surgeon during 2008 to 2017 was retrospectively analyzed. For VUA, we used the standard interrupted suture technique (n=100) with a 3-0 PDS suture. The RS (n=111) was performed with 12-bite suture using 3-0 PDS. The primary endpoints were extravasation and early continence. Demographic and peri-operative data were collected and analyzed using Pearson's chi-square, t-Test and Mann-Whitney U-test. A binary logistic regression analysis was carried out to explore predictors that affected early continence after catheter removal. Results: The rates of early urinary incontinence (UI) were 7.7% vs 42.2% (p<0.001). The duration of catheterization and hospitalization was significantly shorter in the interrupted group (4 days vs 5 days, p<0.001 and 5 days vs 6 days, p<0.001). The groups did not differ significantly in body mass index or prostate volume. There were older patients and higher PSA levels in the group with RS technique. No significant difference was found in the postoperative extravasation rates between both groups (13.5% vs 12%, p=0.742). Conclusion: Running vesicourethral anastomosis increased the rate of early urinary incontinence. Both anastomosis techniques provided a similar rate of postoperative urine extravasation. VUA should only be one of the many criteria that must be considered for the preservation of urinary continence of patients after RRP

Piwi-interacting RNAs as novel prognostic markers in clear cell renal cell carcinomas

Background Piwi-interacting RNAs (piRNAs) are small RNAs of 27–30 nucleotides mapping to transposons or clustering in repeat genomic regions. Preliminary studies suggest an important role in cancerogenesis. This study is the first one investigating their prognostic impact in clear cell renal cell cancer (ccRCC) patients. Methods Three piRNAs (piR-30924, piR-57125, and piR-38756) selected on the basis of initial piRNA microarray analyses were determined using RT-qPCR in non-metastatic (n = 76) and metastatic (n = 30) ccRCC tissue at the time of nephrectomy in comparison to normal renal tissue (n = 77) and tissue from distant ccRCC metastases (n = 13). Primary clinical end points were recurrence-free and overall survival. Results piR-57125 showed lower expression in metastatic than in non-metastatic tumors, whereas the expression of piR-30924 and piR-38756 increased in metastatic tumors. The higher expression of piR-30924 and piR-38756 as well as the lower expression of piR-57125 in metastatic primary tumors were significantly associated with tumor recurrence and overall survival. Multivariate Cox regression analyses revealed both piR-30924 and piR-57125 as independent prognostic predictors. This impact was even more pronounced in non-metastatic patients. Conclusions This study demonstrates that the expression levels of these piRNAs in primary non-metastatic and metastatic ccRCC tissue can serve as potential prognostic biomarkers in combination with clinicopathological factors

Cost‐effectiveness analysis of multiple imaging modalities in diagnosis and follow‐up of intermediate complex cystic renal lesions

Objectives: To compare health-economic aspects of multiple imaging modalities used to monitor renal cysts, the present study evaluates costs and outcomes of patients with Bosniak IIF and III renal cysts detected and followed-up by either contrast-enhanced computed tomography (ceCT), contrast-enhanced magnetic resonance imaging (ceMRI), or contrast-enhanced ultrasonography (CEUS). Patients and methods: A simulation using Markov models was implemented and performed with 10 cycles of 1 year each. Proportionate cohorts were allocated to Markov models by a decision tree processing specific incidences of malignancy and levels of diagnostic performance. Costs of imaging and surgical treatment were investigated using internal data of a European university hospital. Multivariate probabilistic sensitivity analysis was performed to confirm results considering input value uncertainties. Patient outcomes were measured in quality-adjusted life years (QALY), and costs as averages per patient including costs of imaging and surgical treatment. Results: Compared to the 'gold standard' of ceCT, ceMRI was more effective but also more expensive, with a resulting incremental cost-effectiveness ratio (ICER) >€70 000 (Euro) per QALY gained. CEUS was dominant compared to ceCT in both Bosniak IIF and III renal cysts in terms of QALYs and costs. Probabilistic sensitivity analysis confirmed these results in the majority of iterations. Conclusion: Both ceMRI and CEUS can be used as alternatives to ceCT in the diagnosis and follow-up of intermediately complex cystic renal lesions without compromising effectiveness, while CEUS is clearly cost-effective. The economic results apply to a large university hospital and must be adapted for smaller hospitals