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Neuartige Zielvolumendefinition für die Strahlentherapie des Glioblastoma multiforme
No full textBackground: For target delineation in Glioblastoma there are currently two major consensus guidelines being used, the one of the European Organisation for Research and Treatment of Cancer (EORTC) and the one of the Radiation Therapy Oncology Group (RTOG). The resulting target volumes are often large and lead to irradiation of healthy brain tissue. Objective: Primary aim was the analysis of the recurrence pattern in relation to three different target volumes and their volumetric comparison. Since hypothetically recurrences mostly occur locally, it was investigated whether the irradiation volume can be reduced to spare healthy tissue and possibly reduce side effects. Methods: A total of 89 patient data were evaluated using the iPlan radiation planning system and the statistics software SPSS®. Magnetic resonance imaging (MRI) scans from the time of radiation treatment planning were compared with those at the first occurrence of recurrence. Considering changes in T2/fluid-attenuated inversion recovery (FLAIR) sequences on MRI, a novel reduced target volume (PTVNeu) was defined and compared to the conventional methods of EORTC and RTOG.Results: The recurrence pattern of the reduced target volume was comparable to that of the EORTC method. The number of in-field recurrences was 79.5 % vs. 80.8 %, 11 % vs. 8.9 % for marginal recurrences, and 9.6 % vs. 10.3 % for out-of-field recurrences. The reduced target volume with a median of 179 ml was significantly smaller than the target volumes by EORTC and RTOG method (292.9 ml and 452.9 ml, pConclusions: Even with a reduced target volume, most recurrences are located in-field with respect to the PTV. Compared with the conventional methods significantly less surrounding tissue would be irradiated. The results validate the use of reduced irradiation volumes in prospective studies for possible future consolidation of target volume reduction
Mechanical metamaterial sensors: from design to applications
No full textThe integration of mechanical metamaterials with sensor technology has opened new frontiers in the design and application of advanced sensing systems due to their ability to impart unique mechanical properties that enhance sensor functionality. Mechanical metamaterials, with properties derived from their engineered structures rather than their material composition, offer unique advantages such as negative Poisson's ratio, high strength-to-weight ratios, and programmable behaviors. This review explores the dual approaches of incorporating sensors with mechanical metamaterials: metamaterial-supported sensors, where metamaterials provide structural support and enhanced durability to traditional sensors, and metamaterial-integrated sensors, where the metamaterial itself serves as the sensing element. Incorporating metamaterials in sensor design can offer increased sensitivity and precision, enhanced structural integrity and durability, programmability and reconfigurability, as well as lightweight and compact design solutions. Key advancements in the field are presented, highlighting how metamaterials properties can enhance sensor performance in terms of sensitivity, precision, and operational versatility. The review covers the primary materials and fabrication techniques used, including additive manufacturing, molding, and physical vapor deposition, and discusses the challenges associated with the mechanical integration of metamaterials and sensors. Practical applications in pressure, strain, temperature, and biomedical sensing are examined, demonstrating the transformative potential of mechanical metamaterials in creating high-performance, multifunctional sensor systems. The discussion concludes with an outlook on future research directions and potential advancements in the field
Guidance framework to apply best practices in ecological data analysis: lessons learned from building Galaxy-Ecology
No full textNumerous conceptual frameworks exist for best practices in research data and analysis (e.g., Open Science and FAIR principles). In practice, there is a need for further progress to improve transparency, reproducibility, and confidence in ecology. Here, we propose a practical and operational framework for researchers and experts in ecology to achieve best practices for building analytical procedures from individual research projects to production-level analytical pipelines. We introduce the concept of atomization to identify analytical steps that support generalization by allowing us to go beyond single analyses. The term atomization is employed to convey the idea of single analytical steps as “atoms” composing an analytical procedure. When generalized, “atoms” can be used in more than a single case analysis. These guidelines were established during the development of the Galaxy-Ecology initiative, a web platform dedicated to data analysis in ecology. Galaxy-Ecology allows us to demonstrate a way to reach higher levels of reproducibility in ecological sciences by increasing the accessibility and reusability of analytical workflows once atomized and generalized
Does asthma affect the risk of developing breast cancer?
No full textBackgroundThe role of the immune system in cancer defense is likely underappreciated. While there has been longstanding interest in the role of atopic diseases in cancer, only a few studies have tested this hypothesis.MethodsWe analyzed data from 202,055 women participating in the Nurses' Health Study (NHS) and the Nurses' Health Study II (NHS II) to explore whether asthma is associated with breast cancer. We used Cox proportional hazards models to link physician-diagnosed asthma with subsequent incidence of breast cancer.ResultsAcross the two cohorts, we identified 18,403 cases of physician-diagnosed asthma. During 4,393,760 person-years of follow-up, 11,096 incident cases of breast cancer were diagnosed. In NHS, women with asthma had a covariate-adjusted hazard ratio of 0.92 (95% CI: 0.86–0.99) to develop breast cancer compared to women without asthma; the respective HR in NHS II was 0.93 (0.84–1.03), and 0.92 (0.87–0.98) in the pooled analysis. Among never-smokers, the HR for breast cancer was 0.91 (0.81–1.02) in NHS, 0.81 (0.70–0.93) in NHS II, and 0.86 (0.77–0.97) combined. In two large prospective cohorts of women, participants with asthma had a somewhat lower risk of breast cancer. An active immune system may provide protection from breast cancer.ConclusionsIn these longitudinal studies, women with asthma had a somewhat lower risk of breast cancer. This association was most pronounced among never smokers. An active immune system may provide protection from breast cancer
Understanding travel behaviour patterns and their dynamics: applying fuzzy clustering and age-period-cohort analysis on longterm data of German travellers
No full textThis study examines how travel behaviour patterns change over time. It addresses the limitations of traditional segmentation studies, which often focus on static snapshots of travel behaviour. A comprehensive approach is proposed, integrating multi-dimensional segmentation and temporal analysis. Based on a large, repeated, cross- sectional dataset (1983–2018) from Germany, the study employs a research design that combines fuzzy clustering, to identify distinct tourist types including their heterogeneous behaviour, and additive logistic regression analysis, to analyse temporal changes in travel behaviour patterns. The findings reveal five tourist types based on their travel behaviour. These tourist types differ in sociodemographic characteristics and are related to each other. The chance of belonging to those tourist types changes over a tourists' life cycle (age), over time due to external factors (period) and across generations (cohort), providing insights into evolving travel behaviour. The findings from this study can help tourism stakeholders to adapt their strategies to changing tourist behaviour and improve destination management and marketing efforts
Direct ink writing and photocrosslinking of hydroxypropyl cellulose into stable 3d parts using methacrylation and blending
No full textTwo 50% solid content solutions of methacrylated hydroxypropyl cellulose (MAHPC) with respective substitution degrees of 1.85 ± 0.04 (L_MAHPC) and 2.64 ± 0.04 (H_MAHPC) were screened for rheological properties, photocrosslinking kinetics and printability in relevance to direct ink writing (DIW). Photo-rheological and printability studies reveal that the rheological properties of both MAHPC inks are better suited for DIW than those of hydroxypropyl cellulose (HPC) inks. Namely, methacrylate grafting improves shear dynamic moduli at low strain but also shear thinning and shear recovery. Both inks completely cure within 30 s upon shining UV light. Photocrosslinking is found to follow the phenomenological autocatalytic Sestak–Berggren kinetic model. However, prolonged exposure to UV light past full cure upon DIW leads to part fracture. The narrow UV-cure time window consequently precludes the production of multilayer parts using UV-assisted DIW for these neat MAHPC inks. In contrast, when blending MAHPC with HPC, an optimal balance between curing kinetics and DIW conditions is achieved, and stable, high-fidelity 150-layered parts are produced. Altogether this research highlights the need to design the content of photocrosslinkable moieties of cellulose derivatives to photoprint high fidelity and stable 3D parts from HPC inks
Electropneumatic oscillators using nonlinear inflatables
No full textAnimals and robots employ central pattern generators, networks that invoke rhythmic patterns from constant inputs, to orchestrate limb movements during locomotion. Artificial central pattern generators (CPGs) can be either implemented in software or constructed in a physical domain. The former lacks embodiment, inhibiting direct interactions with the physical world. The latter is restricted by a complex translation of abstract functions to the physical domain, e.g., negative feedback, if-then behavior, etc. Here, self-oscillators, a rudimentary type of central pattern generators, that find ground in both the pneumatic and electrical domains are demonstrated. First, the hysteretic behavior of previously developed conical membranes is analyzed in deformation space. This state-space behavior is then transformed to the electrical domain by means of a stretchable strain sensor. Next, an analog comparator distinguishes between the two states and instructs a pneumatic solenoid valve to counteract the current state. As a result, a stable oscillation emerges, with a frequency that is dominated by the physical characteristic of the pneumatic circuit. As such, the proposed electropneumatic oscillator provides a promising platform for building complex CPGs that control interactive neuromorphic robots
