Technische Universität Dresden: Qucosa
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Relative biological effectiveness of low‑energy X‑rays (25 kV) in mutant p53 cancer cells
No full textLow-energy X-rays as used in radiation therapy and diagnostics such as mammography are associated with a certain risk of promoting tumour development, especially in patients with mutations in cancer-related genes like TP53. The present study therefore addressed the relative biological effectiveness (RBE) of low-energy X-rays for two human adenocarcinoma cell lines of the breast (MDA-MB-468) and pancreas (BxPC-3) with a mutation in the TP53 gene. Clonogenic survival and cytogenetic changes in terms of micronuclei (MN) formation were determined following irradiation with 25 kV X-rays and 200 kV reference irradiation in the dose range of 1–8 Gy. Except the frequency of MN-containing binucleated cells (BNC) (BNC + MN/BNC) in breast cancer cells yielding an RBE between 0.6 and 0.8, both cell lines displayed dose-dependent variations of RBE values between 1 and 2 for all biological end points (cell survival, (BNC + MN/BNC), MN/BNC, MN/(BNC + MN)) with increased effectiveness of 25 kV irradiation in pancreatic compared to breast cancer cells. The results confirm previous findings indicating increased effectiveness of low-energy X-rays and underline the necessity of careful risk estimation for cancer screening programmes
Electric‑impulse‑technology: results of a basic investigation into the use of the technology as a selective demolition method in the construction industry
No full textA large proportion of today's building projects are realized in existing buildings. This almost always requires the sensitive deconstruction of existing building fabric. Deconstruction technologies have to fulfill high requirements particularly in inner-city residential areas and during ongoing building use, both for construction projects in the existing building stock and for new construction activities. Currently used demolition technologies rarely meet the growing requirements in building practice. Common demolition and separation methods are characterized by high emissions, such as vibrations and noise, large quantities of blasting material, slow performance progress or high physical effort. An alternative technology is the electrodynamic Electric-Impulse-Technology (EIT). The process technology, initially developed for applications in mining and special civil engineering, is based on the destruction of solid materials by high-voltage pulses. On the basis of large-scale tests in mining dimensions, it was possible to demonstrate high dissolving capacities with low energy input. The research project aimed to investigate the basics for transferring the EIT to low-emission and selective material removal in civil and structural engineering. Extensive laboratory tests were conducted on sand-lime and concrete specimens to verify the adaptation of the EIT. It was found out that the technology is suitable for use in the construction industry. Further research is to be conducted to investigate the identified areas of application in greater depth and to further develop EIT for practical use
Disentangling the trajectories of maternal depressive symptoms and partnership problems in the transition to parenthood and their impact on child adjustment difficulties
No full textMaternal perinatal depression (PND) and partnership problems have been identified to influence the development of later child adjustment difficulties. However, PND and partnership problems are closely linked which makes it difficult to draw conclusions about the exact transmission pathways. The aim of the present study was to investigate to what extent PND symptoms and partnership problems influence each other longitudinally and to examine the influence of their trajectories on child adjustment difficulties at the age of three. Analyses were based on publicly available data from the German family panel “pairfam”. N = 354 mothers were surveyed on depressive symptoms and partnership problems annually from pregnancy (T0) until child age three (T4). Child adjustment difficulties were assessed at age three. Results of latent change score modeling showed that partnership problems predicted change in PND symptoms at T0 and T3 while PND symptoms did not predict change in partnership problems. Child adjustment difficulties at age three were predicted by PND symptoms, but not by partnership problems. Partnership problems predicted externalizing, but not internalizing symptoms. Results underline the effects of family factors for the development of child adjustment difficulties and emphasize the importance of early interventions from pregnancy onwards
Using Direct and Indirect Estimates for Alcohol-Attributable Mortality: A Modelling Study Using the Example of Lithuania
No full textIntroduction: Comparative risk assessments (CRAs) for alcohol use are based on indirect estimates of attributable harm, and usually combine country-specific exposure estimates and global risk relations derived from meta-analyses. CRAs for Eastern European countries, such as Lithuania, base their risk relations not on global risk relations, but on a large Russian cohort study. The availability of a direct estimate of alcohol-attributable mortality following the 2017 implementation of a large increase in alcohol excise taxes in Lithuania has allowed a comparison of these indirect estimates with a country-specific gold standard. Methods: A statistical modelling study compared direct (predictions based on a time-series methodology) and indirect (predictions based on an attributable-fraction methodology) estimates of alcohol-attributable mortality before and after a large increase in alcohol excise taxes in Lithuania. Specifically, Russia-specific versus global relative risks were compared against the gold standard of time-series based predictions. Results: Compared to direct estimates, indirect estimates markedly underestimated the reduction of alcohol-attributable mortality 12 months post intervention by at least 63%. While both of the indirect estimates differed markedly from the direct estimates, the Russia-specific estimates were closer to the direct estimates, primarily due to higher estimates for alcohol-attributable cardiovascular mortality. Discussion: As all indirect estimates were markedly lower than direct estimates, current overall relative risks and price elasticities should be re-evaluated. In particular, global estimates should be replaced by new regional estimates based on cohort studies
Knowledge and inquiry—the missing key for a knowledge-based decision theory
No full textFassio and Gao (2021) object to a knowledge-based decision theory on the ground that it cannot deal with unsuccessful inquiry. One way for inquiry to fail is not to know what one should know. If one’s inquiry fails in this way, is a subsequent choice in any way wrong when based on one’s limited actual knowledge? This paper discusses two strategies for dealing with this problem. On a first strategy, there is nothing wrong with such a choice (but something went wrong prior to one’s choice). On a second strategy, there is something wrong with one’s choice and a knowledge-based decision theory should require that one’s decisions be based on the knowledge one should have, not merely on the knowledge one actually has
Production of protein isolate from pumpkin seed press cake and application of low-fat vegan mayonnaise
No full textNowadays, the press cakes obtained following oil extraction are commonly used as animal feed. Pumpkin seed press cake is rich in nutrients and its high protein content has prompted the research of new methods to increase its usability in the diet of people. Within the scope of this doctoral thesis, protein isolation from pumpkin seed press cake following a defatting procedure was carried out. In this context, the optimization of alkaline extraction conditions was conducted in order to investigate the yield and various functional properties of the proteins obtained from pumpkin seed press cake. While the functional properties of proteins can be improved with various technologies to be used within the scope of protein isolation, at the same time, protein isolation efficiency can be increased. In this context, the effects of ultrasound and high pressure homogenisation at different stages of alkaline extraction were evaluated. Besides nonthermal applications, the effects of enzymatic applications were also examined. It was revealed that protein yield, protein solubility, foaming and emulsification properties were improved by selected treatments compared to alkaline extraction, while a significant increase in protein yield was achieved with high pressure assisted protein isolation treatment compared to other applications in which the effect of different pressure ranges was evaluated. Recently, the production of low-fat mayonnaise is gaining popularity considering its health impacts. Within the scope of the thesis, protein isolate obtained from pumpkin seed press cake is used in the production of low-fat vegan mayonnaise to enrich the nutritional content, as well as the addition of protein isolate with enhanced emulsifying properties as a substitute for eggs, while producing mayonnaise with emulsification properties approaching standard mayonnaise, vegan mayonnaise with improved textural and sensory properties depending on the amount of protein isolate in the ingredients.:1 Motivation
2 Literature review
2.1 Plant proteins
2.2 Pumpkin, pumpkin seed and its press cake
2.3 Protein extraction
2.4 Functional properties of proteins
2.4.1 Solubility
2.4.2 Emulsification
2.4.3 Foaming
2.5 Modification of protein
2.5.1 Physical modification
2.5.2 Enzymatic modification
2.6 Usage of pumpkin, pumpkin seed and its press cake
2.7 Vegan mayonnaise production
3 Objectives of the thesis
4 Materials and methods
4.1 Materials
4.2 Composition of pumpkin seed press cake
4.3 Protein isolation
4.3.1 Control procedure
4.3.2 Ultrasound assisted protein isolation
4.3.3 High pressure homogenisation assisted protein isolation
4.3.4 Enzyme assisted protein isolation
4.4 Technofunctional properties
4.4.1 Protein solubility
4.4.2 Emulsification index
4.4.3 Foaming capacity and stability
4.5 Particle size
4.6 SDS-PAGE profile
4.7 Differential scanning calorimetry
4.8 Colour profile
4.9 Vegan mayonnaise
4.9.1 Vegan mayonnaise production
4.9.2 pH
4.9.3 Emulsion stability
4.9.4 Light microscopy
4.9.5 Colour profile
4.9.6 Texture measurements
4.9.7 Sensory evaluation
4.10 Statistical analysis
5 Result and discussion
5.1 Pumpkin seed press cake composition
5.2 Optimization of the protein extraction procedure
5.3 Ultrasound assisted protein isolation
5.3.1 Protein yield and content
5.3.2 Particle size
5.3.3 Protein solubility
5.3.4 Emulsification properties
5.3.5 Foaming capacity and stability
5.3.6 Protein profile
5.3.7 Thermal properties
5.3.8 Colour characteristics
5.4 High pressure homogenisation assisted protein isolation
5.4.1 Protein yield and content
5.4.2 Particle size
5.4.3 Protein solubility
5.4.4 Emulsification properties
5.4.5 Foaming capacity and stability
5.4.6 Protein profiles
5.4.7 Thermal properties
5.4.8 Colour characteristics
5.5 Enzyme assisted protein isolation
5.5.1 Optimization of the protein extraction procedure
5.5.2 Protein yield and content
5.5.3 Protein profiles
5.5.4 Particle size
5.5.5 Protein solubility
5.5.6 Emulsification properties
5.5.7 Foaming capacity and stability
5.5.8 Thermal properties
5.5.9 Colour characteristics
5.6 Vegan mayonnaise production
5.6.1 pH
5.6.2 Emulsion stability
5.6.3 Microstructure
5.6.4 Colour
5.6.5 Texture
5.6.6 Sensory properties
6 Conclusions
Bibliography
List of figures
List of tables
List of publications
List of presentations and poster
Leptomeningeal Metastases in Melanoma Patients: An Update on and Future Perspectives for Diagnosis and Treatment
No full textLeptomeningeal disease (LMD) is a devastating complication of cancer with a particularly poor prognosis. Among solid tumours, malignant melanoma (MM) has one of the highest rates of metastasis to the leptomeninges, with approximately 10–15% of patients with advanced disease developing LMD. Tumour cells that metastasise to the brain have unique properties that allow them to cross the blood–brain barrier, evade the immune system, and survive in the brain microenvironment. Metastatic colonisation is achieved through dynamic communication between metastatic cells and the tumour microenvironment, resulting in a tumour-permissive milieu. Despite advances in treatment options, the incidence of LMD appears to be increasing and current treatment modalities have a limited impact on survival. This review provides an overview of the biology of LMD, diagnosis and current treatment approaches for MM patients with LMD, and an overview of ongoing clinical trials. Despite the still limited efficacy of current therapies, there is hope that emerging treatments will improve the outcomes for patients with LMD
Single-Site Experience with an Automated Artificial Intelligence Application for Left Ventricular Ejection Fraction Measurement in Echocardiography
No full textLeft ventricular ejection fraction (LVEF) is a key parameter in evaluating left ventricular (LV) function using echocardiography (Echo), but its manual measurement by the modified biplane Simpson (MBS) method is time consuming and operator dependent. We investigated the feasibility of a server-based, commercially available and ready-to use-artificial intelligence (AI) application based on convolutional neural network methods that integrate fully automatic view selection and measurement of LVEF from an entire Echo exam into a single workflow. We prospectively enrolled 1083 consecutive patients who had been referred to Echo for diagnostic or therapeutic purposes. LVEF was measured independently using MBS and AI. Test–retest variability was assessed in 40 patients. The reliability, repeatability, and time efficiency of LVEF measurements were compared between the two methods. Overall, 889 Echos were analyzed by cardiologists with the MBS method and by the AI. Over the study period of 10 weeks, the feasibility of both automatic view classification and seamlessly measured LVEF rose to 81% without user involvement. LVEF, LV end-diastolic and end-systolic volumes correlated strongly between MBS and AI (R = 0.87, 0.89 and 0.93, p < 0.001 for all) with a mean bias of +4.5% EF, −12 mL and −11 mL, respectively, due to impaired image quality and the extent of LV function. Repeatability and reliability of LVEF measurement (n = 40, test–retest) by AI was excellent compared to MBS (coefficient of variation: 3.2% vs. 5.9%), although the median analysis time of the AI was longer than that of the operator-dependent MBS method (258 s vs. 171 s). This AI has succeeded in identifying apical LV views and measuring EF in one workflow with comparable results to the MBS method and shows excellent reproducibility. It offers realistic perspectives for fully automated AI-based measurement of LVEF in routine clinical settings
Fast and label-free intraoperative discrimination of malignant pancreatic tissue by attenuated total reflection infrared spectroscopy
No full textSignificance:
Pancreatic surgery is a highly demanding and routinely applied procedure for the treatment of several pancreatic lesions. The outcome of patients with malignant entities crucially depends on the margin resection status of the tumor. Frozen section analysis for intraoperative evaluation of tissue is still time consuming and laborious.
Aim:
We describe the application of fiber-based attenuated total reflection infrared (ATR IR) spectroscopy for label-free discrimination of normal pancreatic, tumorous, and pancreatitis tissue. A pilot study for the intraoperative application was performed.
Approach:
The method was applied for unprocessed freshly resected tissue samples of 58 patients, and a classification model for differentiating between the distinct tissue classes was established.
Results:
The developed three-class classification model for tissue spectra allows for the delineation of tumors from normal and pancreatitis tissues using a probability score for class assignment. Subsequently, the method was translated into intraoperative application. Fiber optic ATR IR spectra were obtained from freshly resected pancreatic tissue directly in the operating room.
Conclusion:
Our study shows the possibility of applying fiber-based ATR IR spectroscopy in combination with a supervised classification model for rapid pancreatic tissue identification with a high potential for transfer into intraoperative surgical diagnostics
Neurophysiological mechanisms underlying the differential effect of reward prospect on response selection and inhibition
No full textReward and cognitive control play crucial roles in shaping goal-directed behavior. Yet, the behavioral and neural underpinnings of interactive effects of both processes in driving our actions towards a particular goal have remained rather unclear. Given the importance of inhibitory control, we investigated the effect of reward prospect on the modulatory influence of automatic versus controlled processes during response inhibition. For this, a performance-contingent monetary reward for both correct response selection and response inhibition was added to a Simon NoGo task, which manipulates the relationship of automatic and controlled processes in Go and NoGo trials. A neurophysiological approach was used by combining EEG temporal signal decomposition and source localization methods. Compared to a non-rewarded control group, rewarded participants showed faster response execution, as well as overall lower response selection and inhibition accuracy (shifted speed-accuracy tradeoff). Interestingly, the reward group displayed a larger interference of the interactive effects of automatic versus controlled processes during response inhibition (i.e., a larger Simon NoGo effect), but not during response selection. The reward-specific behavioral effect was mirrored by the P3 amplitude, underlining the importance of stimulus–response association processes in explaining variability in response inhibition performance. The selective reward-induced neurophysiological modulation was associated with lower activation differences in relevant structures spanning the inferior frontal and parietal cortex, as well as higher activation differences in the somatosensory cortex. Taken together, this study highlights relevant neuroanatomical structures underlying selective reward effects on response inhibition and extends previous reports on the possible detrimental effect of reward-triggered performance trade-offs on cognitive control processes