31 research outputs found
Maatregelen ter verbetering van de kwaliteit van het oppervlaktewater in Bergambacht
De effectiviteit van maatregelen om de waterkwaliteit in het peilgebied Bergambacht te verbeteren is onderzocht met simulatiemodellen. Combinaties van peilbeheer en bemestingsregime geven geringe verschillen in de uit- en afspoeling van nutriënten. Kroos verwijderen, baggeren en verbeteren van de afvalwaterzuiveringsinstallaties - en combinaties daarvan - verlagen de gemiddelde nutriëntenconcentratie in het oppervlaktewater in het zomerhalfjaar aanzienlijk. Baggeren alleen verlaagt de stikstofconcentratie niet. De kansen om de grenswaarden te bereiken zijn in het kleigebied in het zuiden groter dan in het veengebied en de natuurgebieden in het noorden. Het ontwikkelde modelinstrumentarium kan ook in andere veenweidepolders worden toegepast
An immunohistochemical evaluation of tumor-associated glycans and mucins as targets for molecular imaging of Pancreatic Ductal Adenocarcinoma
Simple Summary: Distinguishing pancreatic cancer from healthy tissue before and during surgery can be enhanced by using molecular tracers directed at molecules on tumor cells allowing high-contrast visualization of tumor tissue, eventually improving diagnosis and surgical removal. Albeit sugar molecules and proteins carrying a large amount of sugars-mucins- have gained significant interest as tumor-specific targets, their relative presence on structures surrounding tumor tissues and lymph node metastases is unknown. The current study shows that the presence of several, but not all, investigated sugar molecules and mucins on pancreatic cancer cells is higher compared to surrounding tissues. Moreover, given their abundance on tumor cells in lymph nodes and their absence on normal lymph nodes, all investigated targets are high-potential targets for visualization of lymph node metastases. This study paves the way for the development of molecular tracers against the targets evaluated herein to allow improvement of pancreatic cancer treatment.Targeted molecular imaging may overcome current challenges in the preoperative and intraoperative delineation of pancreatic ductal adenocarcinoma (PDAC). Tumor-associated glycans Le(a/c/x), sdi-Le(a), sLe(a), sLe(x), sTn as well as mucin-1 (MUC1) and mucin-5AC (MU5AC) have gained significant interest as targets for PDAC imaging. To evaluate their PDAC molecular imaging potential, biomarker expression was determined using immunohistochemistry on PDAC, (surrounding) chronic pancreatitis (CP), healthy pancreatic, duodenum, positive (LN+) and negative lymph node (LN-) tissues, and quantified using a semi-automated digital image analysis workflow. Positive expression on PDAC tissues was found on 83% for Le(a/c/x), 94% for sdi-Le(a), 98% for sLe(a), 90% for sLe(x), 88% for sTn, 96% for MUC1 and 67% for MUC5AC, where all were not affected by the application of neoadjuvant therapy. Compared to PDAC, all biomarkers were significantly lower expressed on CP, healthy pancreatic and duodenal tissues, except for sTn and MUC1, which showed a strong expression on duodenum (sTn tumor:duodenum ratio: 0.6, p 0.9999), respectively. All biomarkers are suitable targets for correct identification of LN+, as well as the distinction of LN+ from LN- tissues. To conclude, this study paves the way for the development and evaluation of Le(a/c/x)-, sdi-Le(a)-, sLe(a)-, sLe(x)- and MUC5AC-specific tracers for molecular imaging of PDAC imaging and their subsequent introduction into the clinic.Surgical oncolog
Electrophysiological correlates of reinforcement learning in young people with Tourette syndrome with and without co-occurring ADHD symptoms
Altered reinforcement learning is implicated in the causes of Tourette syndrome (TS) and attention-deficit/hyperactivity disorder (ADHD). TS and ADHD frequently co-occur but how this affects reinforcement learning has not been investigated. We examined the ability of young people with TS (n = 18), TS+ADHD (N = 17), ADHD (n = 13) and typically developing controls (n = 20) to learn and reverse stimulus-response (S-R) associations based on positive and negative reinforcement feedback. We used a 2 (TS-yes, TS-no) x 2 (ADHD-yes, ADHD-no) factorial design to assess the effects of TS, ADHD, and their interaction on behavioural (accuracy, RT) and event-related potential (stimulus-locked P3, feedback-locked P2, feedback-related negativity, FRN) indices of learning and reversing the S-R associations. TS was associated with intact learning and reversal performance and largely typical ERP amplitudes. ADHD was associated with lower accuracy during S-R learning and impaired reversal learning (significantly reduced accuracy and a trend for smaller P3 amplitude). The results indicate that co-occurring ADHD symptoms impair reversal learning in TS+ADHD. The implications of these findings for behavioural tic therapies are discussed
Maatregelen ter verbetering van de kwaliteit van het oppervlaktewater in Bergambacht
De effectiviteit van maatregelen om de waterkwaliteit in het peilgebied Bergambacht te verbeteren is onderzocht met simulatiemodellen. Combinaties van peilbeheer en bemestingsregime geven geringe verschillen in de uit- en afspoeling van nutriënten. Kroos verwijderen, baggeren en verbeteren van de afvalwaterzuiveringsinstallaties - en combinaties daarvan - verlagen de gemiddelde nutriëntenconcentratie in het oppervlaktewater in het zomerhalfjaar aanzienlijk. Baggeren alleen verlaagt de stikstofconcentratie niet. De kansen om de grenswaarden te bereiken zijn in het kleigebied in het zuiden groter dan in het veengebied en de natuurgebieden in het noorden. Het ontwikkelde modelinstrumentarium kan ook in andere veenweidepolders worden toegepast
Setup for EMI Shielding Effectiveness Tests of Electrically Conductive Polymer Composites at Frequencies up to 3.0 GHz
Conductive polymer composites have been receiving increased interest both from the scientific community and industry with a special focus on electromagnetic interference (EMI) shielding applications. In this paper, we present the design, EM wave simulation, and validation through S-parameters measurements of an EMI shielding effectiveness (SE) tester based on the ASTM D4935 standard, to be used in the development of such materials. EM wave simulations and computer aided design were used in parallel to improve the SE test setup performance, which resulted in a unique low-loss coaxial-spherical-conical smooth transition design that ensured the best tradeoff between sample size and performance. The proposed SE tester has an insertion loss smaller than 1 dB, with good reproducibility and a setup-independent frequency response in the frequency range from a few kHz up to 3 GHz.Novel Aerospace Material