85,145 results on '"Matthias M"'
Search Results
2. The inhibitory action of the chaperone BRICHOS against the α-Synuclein secondary nucleation pathway
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Dhiman Ghosh, Felix Torres, Matthias M. Schneider, Dzmitry Ashkinadze, Harindranath Kadavath, Yanick Fleischmann, Simon Mergenthal, Peter Güntert, Georg Krainer, Ewa A. Andrzejewska, Lily Lin, Jiapeng Wei, Enrico Klotzsch, Tuomas Knowles, and Roland Riek
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Science - Abstract
Abstract The complex kinetics of disease-related amyloid aggregation of proteins such as α-Synuclein (α-Syn) in Parkinson’s disease and Aβ42 in Alzheimer’s disease include primary nucleation, amyloid fibril elongation and secondary nucleation. The latter can be a key accelerator of the aggregation process. It has been demonstrated that the chaperone domain BRICHOS can interfere with the secondary nucleation process of Aβ42. Here, we explore the mechanism of secondary nucleation inhibition of the BRICHOS domain of the lung surfactant protein (proSP-C) against α-Syn aggregation and amyloid formation. We determine the 3D NMR structure of an inactive trimer of proSP-C BRICHOS and its active monomer using a designed mutant. Furthermore, the interaction between the proSP-C BRICHOS chaperone and a substrate peptide has been studied. NMR-based interaction studies of proSP-C BRICHOS with α-Syn fibrils show that proSP-C BRICHOS binds to the C-terminal flexible fuzzy coat of the fibrils, which is the secondary nucleation site on the fibrils. Super-resolution fluorescence microscopy demonstrates that proSP-C BRICHOS runs along the fibrillar axis diffusion-dependently sweeping off monomeric α-Syn from the fibrils. The observed mechanism explains how a weakly binding chaperone can inhibit the α-Syn secondary nucleation pathway via avidity where a single proSP-C BRICHOS molecule is sufficient against up to ~7-40 α-Syn molecules embedded within the fibrils.
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- 2024
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3. Gate-set evaluation metrics for closed-loop optimal control on nitrogen-vacancy center ensembles in diamond
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Philipp J. Vetter, Thomas Reisser, Maximilian G. Hirsch, Tommaso Calarco, Felix Motzoi, Fedor Jelezko, and Matthias M. Müller
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Physics ,QC1-999 ,Electronic computers. Computer science ,QA75.5-76.95 - Abstract
Abstract A recurring challenge in quantum science and technology is the precise control of their underlying dynamics that lead to the desired quantum operations, often described by a set of quantum gates. These gates can be subject to application-specific errors, leading to a dependence of their controls on the chosen circuit, the quality measure and the gate-set itself. A natural solution would be to apply quantum optimal control in an application-oriented fashion. In turn, this requires the definition of a meaningful measure of the contextual gate-set performance. Therefore, we explore and compare the applicability of quantum process tomography, linear inversion gate-set tomography, randomized linear gate-set tomography, and randomized benchmarking as measures for closed-loop quantum optimal control experiments, using a macroscopic ensemble of nitrogen-vacancy centers in diamond as a test-bed. Our work demonstrates the relative trade-offs between those measures and how to significantly enhance the gate-set performance, leading to an improvement across all investigated methods.
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- 2024
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4. Matched-pair analysis of mCRPC patients receiving 177Lu-labeled PSMA-targeted radioligand therapy in a 4-week versus 6-week treatment interval
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Amir Karimzadeh, Charlotte-Sophie Hecker, Matthias M. Heck, Robert Tauber, Calogero D’Alessandria, Wolfgang A. Weber, Matthias Eiber, and Isabel Rauscher
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Prostate-specific membrane antigen (PSMA) ,Radioligand therapy (RLT) ,Metastatic castration-resistant prostate cancer (mCRPC) ,4-week treatment interval ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 - Abstract
Abstract Background The optimal regimen for 177Lu-labeled prostate-specific membrane antigen-targeted radioligand therapy, including treatment intervals, remains under study, with evidence suggesting shorter intervals could benefit patients with high disease volume and rapid progression. This retrospective analysis evaluated treatment toxicity, PSA response, PSA-progression-free survival (PSA-PFS), and overall survival (OS) in matched cohorts of mCRPC patients receiving 177Lu-PSMA-RLT at 4-week versus 6-week intervals. Results A PSA response (PSA decline ≥ 50%) was achieved in 47.8% and 21.7% of patients in the 4-week and 6-week treatment interval groups, respectively (p = 0.12). There was a trend towards longer PSA-PFS in the 4-week group compared to the 6-week group (median PSA-PFS, 26.0 weeks vs. 18.0 weeks; HR 0.6; p = 0.2). Although not statistically significant, there was a trend towards shorter OS in the 4-week group compared to the 6-week group (median OS, 15.1 months vs. 18.4 months; HR 1.3; p = 0.5). The 4-week group had a significantly greater decrease in leucocyte and platelet counts compared to the 6-week group (38.5% vs. 18.2% and 26.7% vs. 10.7%; p = 0.047 and p = 0.02). Severe adverse events were modest in both groups. Conclusions Intensifying treatment intervals from 6 weeks to 4 weeks showed some improvements in PSA response and PSA-PFS for mCRPC patients, but did not significantly affect OS. Additionally, bone marrow reserve was significantly reduced with the intensified regimen. Therefore, the overall benefit remains uncertain, and further prospective studies are needed to compare 4-week and 6-week intervals regarding toxicity, treatment response, and outcome.
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- 2024
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5. Single-molecule digital sizing of proteins in solution
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Georg Krainer, Raphael P. B. Jacquat, Matthias M. Schneider, Timothy J. Welsh, Jieyuan Fan, Quentin A. E. Peter, Ewa A. Andrzejewska, Greta Šneiderienė, Magdalena A. Czekalska, Hannes Ausserwoeger, Lin Chai, William E. Arter, Kadi L. Saar, Therese W. Herling, Titus M. Franzmann, Vasilis Kosmoliaptsis, Simon Alberti, F. Ulrich Hartl, Steven F. Lee, and Tuomas P. J. Knowles
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Science - Abstract
Abstract The physical characterization of proteins in terms of their sizes, interactions, and assembly states is key to understanding their biological function and dysfunction. However, this has remained a difficult task because proteins are often highly polydisperse and present as multicomponent mixtures. Here, we address this challenge by introducing single-molecule microfluidic diffusional sizing (smMDS). This approach measures the hydrodynamic radius of single proteins and protein assemblies in microchannels using single-molecule fluorescence detection. smMDS allows for ultrasensitive sizing of proteins down to femtomolar concentrations and enables affinity profiling of protein interactions at the single-molecule level. We show that smMDS is effective in resolving the assembly states of protein oligomers and in characterizing the size of protein species within complex mixtures, including fibrillar protein aggregates and nanoscale condensate clusters. Overall, smMDS is a highly sensitive method for the analysis of proteins in solution, with wide-ranging applications in drug discovery, diagnostics, and nanobiotechnology.
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- 2024
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6. Health economic evaluation of weight reduction interventions in individuals suffering from overweight or obesity and a musculoskeletal diagnosis—a systematic review
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Alexander P. Schurz, Matthias M. Walter, Melanie Liechti, Ron Clijsen, Tom Deliens, Jan Taeymans, and Nathanael Lutz
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Cost-effectiveness analysis ,Health economic evaluation ,Weight reduction programs ,Weight loss ,Overweight ,Musculoskeletal diseases ,Diseases of the musculoskeletal system ,RC925-935 - Abstract
Abstract Background Most of the worldwide population is overweight and suffers from the resulting musculoskeletal comorbidities such as knee osteoarthritis or back pain. Practice guidelines recommend weight loss interventions for individuals suffering from these conditions. This systematic review investigated whether including a weight loss intervention in the musculoskeletal therapy of these individuals was cost-effective compared to administering the musculoskeletal therapy alone. Methods This study followed the PRISMA guidelines to systematically and independently search six databases and select full health economic evaluations published up to May 2024 from health care or societal perspectives according to predefined eligibility criteria. Cost data were standardised to 2023 Belgium Euros. The methodological quality was assessed using two health economic-specific checklists. Results The searches produced 5′305 references, of which 8 studies were selected for a total of 1′726 participants. The interventions consisted of different exercise plans and nutritional targets. Six values were in the north-eastern; leading to increased quality-adjusted life year (QALY) and higher costs; and two in the south-eastern quadrant of the cost-utility plane; leading to increased QALYs and lower costs. Two studies observed no differences in QALYs. Incremental cost utility ratios (ICUR) ranged from €13′580.10 to €34′412.40 per additional QALY from a healthcare perspective. From a societal perspective, the ICUR was €30′274.84. The included studies fulfilled 86 percent of the criteria in trial-based economic evaluations and 57 percent in model-based economic evaluations. The most common limitations of the studies were related to appropriate cost measures’ specifications, research questions, time horizon choices, and sensitivity analyses. Conclusions This systematic review showed weak but consistent evidence of cost-effectiveness for adding a weight loss intervention to musculoskeletal therapy for individuals with overweight, from either perspective. Further economic evaluations should evaluate the long-term cost-effectiveness of the intervention. Trial registration International Platform of Registered Systematic Review and Meta-analysis Protocols INPLASY (2022,110,122).
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- 2024
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7. Development of Polar BODIPY-Tetrazines for Rapid Pretargeted Fluorescence Imaging
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Markus Staudt, Lars Hvass, Marius Müller, Rocío García-Vázquez, Jesper Tranekjær Jo̷rgensen, Vladimir Shalgunov, Umberto Maria Battisti, Andreas Kjær, and Matthias M. Herth
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Chemistry ,QD1-999 - Published
- 2024
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8. Performance of different CT enhancement quantification methods as predictors of pancreatic cancer recurrence after upfront surgery
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Sherif A. Mohamed, Alina Barlemann, Verena Steinle, Tobias Nonnenmacher, Michelle Güttlein, Thilo Hackert, Martin Loos, Matthias M. Gaida, Hans-Ulrich Kauczor, Miriam Klauss, and Philipp Mayer
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Pancreatic cancer ,Pancreatic ductal adenocarcinoma ,Computed tomography ,Enhancement ,Recurrence ,Upfront surgery ,Medicine ,Science - Abstract
Abstract The prognosis of pancreatic cancer (PDAC) after tumor resection remains poor, mostly due to a high but variable risk of recurrence. A promising tool for improved prognostication is the quantification of CT tumor enhancement. For this, various enhancement formulas have been used in previous studies. However, a systematic comparison of these formulas is lacking. In the present study, we applied twenty-three previously published CT enhancement formulas to our cohort of 92 PDAC patients who underwent upfront surgery. We identified seven formulas that could reliably predict tumor recurrence. Using these formulas, weak tumor enhancement was associated with tumor recurrence at one and two years after surgery (p ≤ 0.030). Enhancement was inversely associated with adverse clinicopathological features. Low enhancement values were predictive of a high recurrence risk (Hazard Ratio ≥ 1.659, p ≤ 0.028, Cox regression) and a short time to recurrence (TTR) (p ≤ 0.027, log-rank test). Some formulas were independent predictors of TTR in multivariate models. Strikingly, almost all of the best-performing formulas measure solely tumor tissue, suggesting that normalization to non-tumor structures might be unnecessary. Among the top performers were also the absolute arterial/portal venous tumor attenuation values. These can be easily implemented in clinical practice for better recurrence prediction, thus potentially improving patient management.
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- 2024
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9. A comparison of the TempO-Seq and Affymetrix microarray platform using RTqPCR validation
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Matthias M. Wehr, Stella Marie Reamon-Buettner, Detlef Ritter, Jan Knebel, Monika Niehof, and Sylvia E. Escher
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TempOSeq ,Affymetrix ,Microarray ,RTqPCR ,RT2 profiling arrays ,Chemical perturbation ,Biotechnology ,TP248.13-248.65 ,Genetics ,QH426-470 - Abstract
Abstract Next-generation risk assessment relies on mechanistic data from new approach methods, including transcriptome data. Various technologies, such as high-throughput targeted sequencing methods and microarray technologies based on hybridization with complementary probes, are used to determine differentially expressed genes (DEGs). The integration of data from different technologies requires a good understanding of the differences arising from the use of various technologies. To better understand the differences between the TempO-Seq platform and Affymetrix chip technology, whole-genome data for the volatile compound dimethylamine were compared. Selected DEGs were also confirmed using RTqPCR validation. Although the overlap of DEGs between TempO-Seq and Affymetrix was no higher than 37%, a comparison of the gene regulation in terms of log2fold changes revealed a very high concordance. RTqPCR confirmed the majority of DEGs from either platform in the examined dataset. Only a few conflicts were found (11%), while 22% were not confirmed, and 3% were not detected. Despite the observed differences between the two platforms, both can be validated using RTqPCR. Here we highlight some of the differences between the two platforms and discuss their applications in toxicology.
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- 2024
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10. Molecular properties and diagnostic potential of monoclonal antibodies targeting cytotoxic α-synuclein oligomers
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Janni Nielsen, Johanne Lauritsen, Jannik N. Pedersen, Jan S. Nowak, Malthe K. Bendtsen, Giulia Kleijwegt, Kaija Lusser, Laia C. Pitarch, Julián V. Moreno, Matthias M. Schneider, Georg Krainer, Louise Goksøyr, Paul Khalifé, Sanne Simone Kaalund, Susana Aznar, Magnus Kjærgaard, Vita Sereikaité, Kristian Strømgaard, Tuomas P. J. Knowles, Morten Agertoug Nielsen, Adam F. Sander, Marina Romero-Ramos, and Daniel E. Otzen
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Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract α-Synuclein (α-syn) accumulates as insoluble amyloid but also forms soluble α-syn oligomers (αSOs), thought to be even more cytotoxic than fibrils. To detect and block the unwanted activities of these αSOs, we have raised 30 monoclonal antibodies (mAbs) against different forms of αSOs, ranging from unmodified αSOs to species stabilized by lipid peroxidation products and polyphenols, αSOs formed by C-terminally truncated α-syn, and multivalent display of α-syn on capsid virus-like particles (cVLPs). While the mAbs generally show a preference for αSOs, they also bind fibrils, but to variable extents. Overall, we observe great diversity in the mAbs’ relative affinities for monomers and αSOs, varied requirements for the C-terminal extension of α-syn, and only a modest effect on α-syn fibrillation. Several mAbs show several orders of magnitude preference for αSOs over monomers in in-solution studies, while the commercial antibody MJF14 only bound 10-fold more strongly to αSOs than monomeric α-syn. Gratifyingly, seven mAbs almost completely block αSO permeabilization of membrane vesicles. Five selected mAbs identified α-syn-related pathologies like Lewy bodies (LBs) and Lewy Neurites, as well as Glial Cytoplasmic Inclusions in postmortem brains from people diagnosed for PD, dementia with LBs or multiple system atrophy, although to different extents. Three mAbs were particularly useful for pathological evaluation of postmortem brain human tissue, including early stages of PD. Although there was no straightforward connection between the mAbs’ biophysical and immunohistochemical properties, it is encouraging that this comprehensive collection of mAbs able to recognize different aggregated α-syn species in vitro also holds diagnostic potential.
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- 2024
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11. The impact of the Gannon Storm of May 2024 on the radiation fields at aviation altitudes and in low earth orbits
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Kai Schennetten, Daniel Matthiä, Matthias M. Meier, Thomas Berger, and Michael Wirtz
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space weather ,solar energetic particle (SEP) ,ground level enhancement (GLE) ,radiation field ,low earth orbit (LEO) ,radiation protection ,Astronomy ,QB1-991 ,Geophysics. Cosmic physics ,QC801-809 - Abstract
In May 2024 the strongest geomagnetic storm since the Halloween storms of 2003 occurred. Media reported worldwide about the space weather situation and its effects on the infrastructure. Of particular interest were reports claiming severe effects on the radiation exposure at aviation altitudes, although no data supporting this assertion were available at that time. In this work the different aspects that affect the radiation exposure at aviation altitudes are discussed for the event. Furthermore, the corresponding dose rates are evaluated and compared to data from Low Earth Orbit. Model calculations indicate an additional contribution to the radiation field at aviation altitudes due to this extraordinary space weather situation, although the dose rates were still in the lowest category D0 of the space weather D-index, i.e., within the dose rate variation of a solar cycle.
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- 2024
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12. β-hydroxybutyrate recapitulates the beneficial effects of ketogenic metabolic therapy in polycystic kidney disease
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Jacob A. Torres, Nickolas Holznecht, David A. Asplund, Bradley C. Kroes, Tselmeg Amarlkhagva, Matthias M. Haeffner, Elizabeth H. Sharpe, Stella Koestner, Sebastian Strubl, Margaret F. Schimmel, Samantha Kruger, Shagun Agrawal, Brina A. Aceves, Muthusamy Thangaraju, and Thomas Weimbs
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Therapy ,Pathophysiology ,Diet ,Science - Abstract
Summary: Autosomal-dominant polycystic kidney disease (ADPKD) is a common monogenic disease characterized by the formation of fluid-filled renal cysts, loss of mitochondrial function, decreased fatty acid oxidation, increased glycolysis, and likely renal failure. We previously demonstrated that inducing a state of ketosis ameliorates or reverses PKD progression in multiple animal models. In this study, we compare time-restricted feeding and 48-h periodic fasting regimens in both juvenile and adult Cy/+ rats. Both fasting regimens potently prevent juvenile disease progression and partially reverse PKD in adults. To explore the mechanism of fasting, we administered β-hydroxybutyrate (BHB) to Cy/+ rats and orthologous mouse models of PKD (Pkd1RC/RC, Pkd1-Ksp:Cre). BHB recapitulated the effects of fasting in these models independent of stereoisomer, suggesting the effects of BHB are largely due to its signaling functions. These findings implicate the use of ketogenic metabolic therapy and BHB supplementation as potential disease modifiers of PKD and point toward underlying mechanisms.
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- 2024
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13. TNFR1 signaling promotes pancreatic tumor growth by limiting dendritic cell number and function
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Muhammad S. Alam, Matthias M. Gaida, Hagen R. Witzel, Shizuka Otsuka, Aamna Abbasi, Theresa Guerin, Abdalla Abdelmaksoud, Nathan Wong, Margaret C. Cam, Serguei Kozlov, and Jonathan D. Ashwell
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inflammation ,TNFR1 ,TNF-α ,pancreatic adenocarcinoma ,PDAC ,KPC mice ,Medicine (General) ,R5-920 - Abstract
Summary: Pancreatic adenocarcinoma (PDAC) is one the most intractable cancers, in part due to its highly inflammatory microenvironment and paucity of infiltrating dendritic cells (DCs). Here, we find that genetic ablation or antibody blockade of tumor necrosis factor receptor 1 (TNFR1) enhanced intratumor T cell activation and slowed PDAC growth. While anti-PD-1 checkpoint inhibition alone had little effect, it further enhanced intratumor T cell activation in combination with anti-TNFR1. The major cellular alteration in the tumor microenvironment in the absence of TNFR1 signaling was a large increase in DC number and immunostimulatory phenotype. This may reflect a direct effect on DCs, because TNF induced TNFR1-dependent apoptosis of bone-marrow-derived DCs. The therapeutic response to anti-TNFR1 alone was superior to the combination of DC-activating agonistic anti-CD40 and Flt3 ligand (Flt3L). These observations suggest that targeting TNFR1, perhaps in concert with other strategies that promote DC generation and mobilization, may have therapeutic benefits.
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- 2024
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14. Indium-111 radiolabelling of a brain-penetrant Aβ antibody for SPECT imaging
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Tobias Gustavsson, Matthias M. Herth, Dag Sehlin, and Stina Syvänen
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spect imaging ,amyloid-beta ,antibody ,indium-111 ,Medicine - Abstract
Background: The development of bispecific antibodies that can traverse the blood–brain barrier has paved the way for brain-directed immunotherapy and when radiolabelled, immunoPET imaging. The objective of this study was to investigate how indium-111 (111In) radiolabelling with compatible chelators affects the brain delivery and peripheral biodistribution of the bispecific antibody RmAb158-scFv8D3, which binds to amyloid-beta (Aβ) and the transferrin receptor (TfR), in Aβ pathology-expressing tg-ArcSwe mice and aged-matched wild-type control mice. Methods: Bispecific RmAb158-scFv8D3 (biAb) was radiolabelled with 111In using CHX-A”-DTPA, DOTA, or DOTA-tetrazine (DOTA-Tz). Affinity toward TfR and Aβ, as well as stability, was investigated in vitro. Mice were then intravenously administered with the three different radiolabelled biAb variants, and blood samples were collected for monitoring pharmacokinetics. Brain concentration was quantified after 2 and 72 h, and organ-specific retention was measured at 72 h by gamma counting. A subset of mice also underwent whole-body Single-photon emission computed tomography (SPECT) scanning at 72 h after injection. Following post-mortem isolation, the brains of tg-ArcSwe and WT mice were sectioned, and the spatial distribution of biAb was further investigated with autoradiography. Results: All three [111In]biAb variants displayed similar blood pharmacokinetics and brain uptake at 2 h after administration. Radiolabelling did not compromise affinity, and all variants showed good stability, especially the DOTA-Tz variant. Whole-body SPECT scanning indicated high liver, spleen, and bone accumulation of all [111In]biAb variants. Subsequent ex vivo measurement of organ retention confirmed SPECT data, with retention in the spleen, liver, and bone – with very high bone marrow retention. Ex vivo gamma measurement of brain tissue, isolated at 72 h post-injection, and ex vivo autoradiography showed that WT mice, despite the absence of Aβ, exhibited comparable brain concentrations of [111In]biAb as those found in the tg-ArcSwe brain. Conclusions: The successful 111In-labelling of biAb with retained binding to TfR and Aβ, and retained ability to enter the brain, demonstrated that 111In can be used to generate radioligands for brain imaging. A high degree of [111In]biAb in bone marrow and intracellular accumulation in brain tissue indicated some off-target interactions or potential interaction with intrabrain TfR resulting in a relatively high non-specific background signal.
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- 2024
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15. A monthly gridded burned area database of national wildland fire data
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Andrina Gincheva, Juli G. Pausas, Andrew Edwards, Antonello Provenzale, Artemi Cerdà, Chelene Hanes, Dominic Royé, Emilio Chuvieco, Florent Mouillot, Gabriele Vissio, Jesús Rodrigo, Joaquin Bedía, John T. Abatzoglou, José María Senciales González, Karen C. Short, Mara Baudena, Maria Carmen Llasat, Marta Magnani, Matthias M. Boer, Mauro E. González, Miguel Ángel Torres-Vázquez, Paolo Fiorucci, Peter Jacklyn, Renata Libonati, Ricardo M. Trigo, Sixto Herrera, Sonia Jerez, Xianli Wang, and Marco Turco
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Science - Abstract
Abstract We assembled the first gridded burned area (BA) database of national wildfire data (ONFIRE), a comprehensive and integrated resource for researchers, non-government organisations, and government agencies analysing wildfires in various regions of the Earth. We extracted and harmonised records from different regions and sources using open and reproducible methods, providing data in a common framework for the whole period available (starting from 1950 in Australia, 1959 in Canada, 1985 in Chile, 1980 in Europe, and 1984 in the United States) up to 2021 on a common 1° × 1° grid. The data originate from national agencies (often, ground mapping), thus representing the best local expert knowledge. Key opportunities and limits in using this dataset are discussed as well as possible future expansions of this open-source approach that should be explored. This dataset complements existing gridded BA data based on remote sensing and offers a valuable opportunity to better understand and assess fire regime changes, and their drivers, in these regions. The ONFIRE database can be freely accessed at https://zenodo.org/record/8289245 .
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- 2024
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16. Synthesis and evaluation of fluorine-18 labelled tetrazines as pre-targeting imaging agents for PET
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Eva Schlein, Johanna Rokka, Luke R. Odell, Sara Lopes van den Broek, Matthias M. Herth, Umberto M. Battisti, Stina Syvänen, Dag Sehlin, and Jonas Eriksson
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Inverse electron demand Diels–Alder reaction ,IEDDA ,Pre-targeting ,Tetrazine ,Trans-cyclooctene ,TCO ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Abstract Background The brain is a challenging target for antibody-based positron emission tomography (immunoPET) imaging due to the restricted access of antibody-based ligands through the blood–brain barrier (BBB). To overcome this physiological obstacle, we have previously developed bispecific antibody ligands that pass through the BBB via receptor-mediated transcytosis. While these radiolabelled ligands have high affinity and specificity, their long residence time in the blood and brain, typical for large molecules, poses another challenge for PET imaging. A viable solution could be a two-step pre-targeting approach which involves the administration of a tagged antibody that accumulates at the target site in the brain and then clears from the blood, followed by administration of a small radiolabelled molecule with fast kinetics. This radiolabelled molecule can couple to the tagged antibody and thereby make the antibody localisation visible by PET imaging. The in vivo linkage can be achieved by using the inverse electron demand Diels–Alder reaction (IEDDA), with trans-cyclooctene (TCO) and tetrazine groups participating as reactants. In this study, two novel 18F-labelled tetrazines were synthesized and evaluated for their potential use as pre-targeting imaging agents, i.e., for their ability to rapidly enter the brain and, if unbound, to be efficiently cleared with minimal background retention. Results The two compounds, a methyl tetrazine [18F]MeTz and an H-tetrazine [18F]HTz were radiolabelled using a two-step procedure via [18F]F-Py-TFP synthesized on solid support followed by amidation with amine-bearing tetrazines, resulting in radiochemical yields of 24% and 22%, respectively, and a radiochemical purity of > 96%. In vivo PET imaging was performed to assess their suitability for in vivo pre-targeting. Time-activity curves from PET-scans showed [18F]MeTz to be the more pharmacokinetically suitable agent, given its fast and homogenous distribution in the brain and rapid clearance. However, in terms of rection kinetics, H-tetrazines are advantageous, exhibiting faster reaction rates in IEDDA reactions with dienophiles like trans-cyclooctenes, making [18F]HTz potentially more beneficial for pre-targeting applications. Conclusion This study demonstrates a significant potential of [18F]MeTz and [18F]HTz as agents for pre-targeted PET brain imaging due to their efficient brain uptake, swift clearance and appropriate chemical stability.
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- 2024
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17. Exponentiation of parametric Hamiltonians via unitary interpolation
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Michael Schilling, Francesco Preti, Matthias M. Müller, Tommaso Calarco, and Felix Motzoi
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Physics ,QC1-999 - Abstract
The effort to generate matrix exponentials and associated differentials, required to determine the time evolution of quantum systems, frequently constrains the evaluation of problems in quantum control theory, variational circuit compilation, or Monte Carlo sampling. We introduce two ideas for the time-efficient approximation of matrix exponentials of linear multiparametric Hamiltonians. We modify the Suzuki-Trotter product formula from an approximation to an interpolation scheme to improve both accuracy and walltime. This allows us to achieve high fidelities within a single interpolation step, which can be computed directly from cached matrices. Furthermore, we define the interpolation on a grid of system parameters, and show that the interpolation infidelity converges with fourth-order accuracy in the number of interpolation bins.
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- 2024
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18. Modeling the Probability of Dry Lightning‐Induced Wildfires in Tasmania: A Machine Learning Approach
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Amila M. K. Wickramasinghe, Matthias M. Boer, Calum X. Cunningham, Rachael H. Nolan, David M. J. S. Bowman, and Grant J. Williamson
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dry lightning fire ,machine learning ,Tasmania ,lightning ignition probability ,wildfire ,biophysical variables ,Geophysics. Cosmic physics ,QC801-809 - Abstract
Abstract Dry lightning is a prevalent episodic natural ignition source for wildfires, particularly in remote regions where such fires can escalate into uncontrollable events, burning extensive areas. In this study, we aimed to understand the interplay of environmental, fuel, and geographical factors in evaluating the probability of fire initiation following dry lightning strikes in Tasmania, Australia. We integrated dry lightning, active fire records, and gridded data on fire weather, fuel, and topography into a binary classification framework for both fire‐initiating and non‐fire‐causing lightning strikes. Employing statistical and machine learning techniques, we quantified the likelihood of fire initiation due to dry lightning, with the resampled Random Forest model exhibiting notable performance with an ROC‐AUC value of 0.98. Our findings highlight how fuel characteristics and moisture content associated with particular vegetation types influence fire initiation and provide an objective approach for identifying susceptible regions of dry lightning ignitions, informing associated fire management responses.
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- 2024
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19. Imaging differentiation of solid pseudopapillary neoplasms and neuroendocrine neoplasms of the pancreas
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Ekaterina Khristenko, Matthias M. Gaida, Christine Tjaden, Verena Steinle, Martin Loos, Korbinian Krieger, Tim F. Weber, Hans-Ulrich Kauczor, Miriam Klauß, and Philipp Mayer
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solid pseudopapillary neoplasm ,Frantz tumor ,pancreatic neuroendocrine neoplasm ,pancreatic neuroendocrine carcinoma ,computed tomography ,magnetic resonance imaging ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 - Abstract
Purpose: The present study aimed to compare the computed tomography (CT) and magnetic resonance imaging (MRI) features of solid pseudopapillary neoplasms (SPNs) and pancreatic neuroendocrine neoplasms (pNENs). Method: Lesion imaging features of 39 patients with SPNs and 127 patients with pNENs were retrospectively extracted from 104 CT and 91 MRI scans. Results: Compared to pNEN patients, SPN patients were significantly younger (mean age 51.8 yrs versus 32.7 yrs) and more often female (female: male ratio, 5.50:1 versus 1.19:1). Most SPNs and pNENs presented as well-defined lesions with an expansive growth pattern. SPNs more often appeared as round or ovoid lesions, compared to pNENs which showed a lobulated or irregular shape in more than half of cases (p
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- 2024
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20. The current landscape of factor XI inhibitors
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Matthias M. Engelen, Charlotte Van Edom, Andreas Verstraete, Peter Verhamme, and Thomas Vanassche
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Thrombosis ,Hemostasis ,FXI inhibitors ,Intrinsic pathway ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
Anticoagulant therapy has always been tightly connected with bleeding risk, as two sides of the same coin. New insights in thrombosis and hemostasis prompted the development of intrinsic pathway inhibitors that promise to uncouple thrombosis and hemostasis. Treating and preventing thrombotic complications without the associated bleeding risk opens up many new possibilities for patients with an unmet need with the current anticoagulant drugs. Many candidate drugs are being investigated in phase I, II, and III clinical trials. In this review, we will introduce the new insights driving this evolution in drug development, whereafter the drugs under development and their clinical trials will be discussed.
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- 2024
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21. Environmental correlates of the forest carbon distribution in the Central Himalayas
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Shiva Khanal, Rachael H. Nolan, Belinda E. Medlyn, and Matthias M. Boer
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aboveground carbon ,disturbance ,environmental drivers ,forest ,Himalaya ,soil organic carbon ,Ecology ,QH540-549.5 - Abstract
Abstract Understanding the biophysical limitations on forest carbon across diverse ecological regions is crucial for accurately assessing and managing forest carbon stocks. This study investigates the role of climate and disturbance on the spatial variation of two key forest carbon pools: aboveground carbon (AGC) and soil organic carbon (SOC). Using plot‐level carbon pool estimates from Nepal's national forest inventory and structural equation modelling, we explore the relationship of forest carbon stocks to broad‐scale climatic water and energy availability and fine‐scale terrain and disturbance. The forest AGC and SOC models explained 25% and 59% of the observed spatial variation in forest AGC and SOC, respectively. Among the evaluated variables, disturbance exhibited the strongest negative correlation with AGC, while the availability of climatic energy demonstrated the strongest negative correlation with SOC. Disturbances such as selective logging and firewood collection result in immediate forest carbon loss, while soil carbon changes take longer to respond. The lower decomposition rates in the high‐elevation region, due to lower temperatures, preserve organic matter and contribute to the high SOC stocks observed there. These results highlight the critical role of climate and disturbance regimes in shaping landscape patterns of forest carbon stocks. Understanding the underlying drivers of these patterns is crucial for forest carbon management and conservation across diverse ecological zones including the Central Himalayas.
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- 2024
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22. Optimization of Non-Alloyed Backside Ohmic Contacts to N-Face GaN for Fully Vertical GaN-on-Silicon-Based Power Devices
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Youssef Hamdaoui, Sofie S. T. Vandenbroucke, Sondre Michler, Katir Ziouche, Matthias M. Minjauw, Christophe Detavernier, and Farid Medjdoub
- Subjects
GaN-on-Si ,N-face N-GaN ohmic contact ,backside contact ,fully vertical ,power devices ,Mechanical engineering and machinery ,TJ1-1570 - Abstract
In the framework of fully vertical GaN-on-Silicon device technology development, we report on the optimization of non-alloyed ohmic contacts on the N-polar n+-doped GaN face backside layer. This evaluation is made possible by using patterned TLMs (Transmission Line Model) through direct laser writing lithography after locally removing the substrate and buffer layers in order to access the n+-doped backside layer. As deposited non-alloyed metal stack on top of N-polar orientation GaN layer after buffer layers removal results in poor ohmic contact quality. To significantly reduce the related specific contact resistance, an HCl treatment is applied prior to metallization under various time and temperature conditions. A 3 min HCl treatment at 70 °C is found to be the optimum condition to achieve thermally stable high ohmic contact quality. To further understand the impact of the wet treatment, SEM (Scanning Electron Microscopy) and XPS (X-ray Photoelectron Spectroscopy) analyses were performed. XPS revealed a decrease in Ga-O concentration after applying the treatment, reflecting the higher oxidation susceptibility of the N-polar face compared to the Ga-polar face, which was used as a reference. SEM images of the treated samples show the formation of pyramids on the N-face after HCl treatment, suggesting specific wet etching planes of the GaN crystal from the N-face. The size of the pyramids is time-dependent; thus, increasing the treatment duration results in larger pyramids, which explains the degradation of ohmic contact quality after prolonged high-temperature HCl treatment.
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- 2024
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23. A Fluorescent Probe as a Lead Compound for a Selective α‑Synuclein PET Tracer: Development of a Library of 2‑Styrylbenzothiazoles and Biological Evaluation of [18F]PFSB and [18F]MFSB
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Adriana Di Nanni, Ran Sing Saw, Umberto M. Battisti, Gregory D. Bowden, Adam Boeckermann, Kaare Bjerregaard-Andersen, Bernd J. Pichler, Kristina Herfert, Matthias M. Herth, and Andreas Maurer
- Subjects
Chemistry ,QD1-999 - Published
- 2023
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24. Plot-level estimates of aboveground biomass and soil organic carbon stocks from Nepal’s forest inventory
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Shiva Khanal and Matthias M. Boer
- Subjects
Science - Abstract
Abstract Given the contribution of deforestation and forest degradation to the global carbon cycle, forest resources are critical to mitigating the global climate change effects. Improved forest monitoring across different biomes is important to understand forest dynamics better and improve global projections of future atmospheric CO2 concentration. Better quantification of the forest carbon cycle advances scientific understanding and informs global negotiations about carbon emissions reduction. High-quality estimates of forest carbon stocks are currently scarce in many developing countries. Here, we present the most comprehensive georeferenced data set to date of plot-level forest carbon estimates for Nepal. Based on field observations from Nepal’s national forest inventory of 2010–2014; the data set includes estimates for two major forest carbon pools, aboveground biomass (AGB) and soil organic carbon (SOC) stocks from 2,009 and 1,156 inventory plots, respectively. The dataset fills an important knowledge gap about forest carbon stocks in the Central Himalayas, a region with highly heterogeneous environmental conditions and rich biodiversity that is poorly represented in existing global estimates of forest carbon.
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- 2023
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25. Impact of the South Atlantic Anomaly on radiation exposure at flight altitudes during solar minimum
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Matthias M. Meier, Thomas Berger, Thomas Jahn, Daniel Matthiä, Mona C. Plettenberg, Markus Scheibinger, Kai Schennetten, and Michael Wirtz
- Subjects
Medicine ,Science - Abstract
Abstract The South Atlantic Anomaly (SAA) is a geographical region over the South Atlantic Ocean where the inner Van Allen radiation belt extends down particularly close to Earth. This leads to highly increased levels of ionizing radiation and related impacts on spacecraft in Low Earth Orbits, e.g., correspondingly increased radiation exposure of astronauts and electronic components on the International Space Station. According to an urban legend, the SAA is also supposed to affect the radiation field in the atmosphere even down to the altitudes of civil aviation. In order to identify and quantify any additional contributions to the omnipresent radiation exposure due to the Galactic Cosmic Radiation at flight altitudes, comprehensive measurements were performed crossing the geographical region of the SAA at an altitude of 13 km in a unique flight mission—Atlantic Kiss. No indication of increased radiation exposure was found.
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- 2023
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26. Development of a 99mTc-labeled tetrazine for pretargeted SPECT imaging using an alendronic acid-based bone targeting model
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Lennart Bohrmann, Christian B. M. Poulie, Cristina Rodríguez-Rodríguez, Stoyan Karagiozov, Katayoun Saatchi, Matthias M. Herth, and Urs O. Häfeli
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Medicine ,Science - Published
- 2024
27. Mapping soil organic carbon stocks in Nepal’s forests
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Shiva Khanal, Rachael H. Nolan, Belinda E. Medlyn, and Matthias M. Boer
- Subjects
Medicine ,Science - Abstract
Abstract Comprehensive forest carbon accounting requires reliable estimation of soil organic carbon (SOC) stocks. Despite being an important carbon pool, limited information is available on SOC stocks in global forests, particularly for forests in mountainous regions, such as the Central Himalayas. The availability of consistently measured new field data enabled us to accurately estimate forest soil organic carbon (SOC) stocks in Nepal, addressing a previously existing knowledge gap. Our method involved modelling plot-based estimates of forest SOC using covariates related to climate, soil, and topographic position. Our quantile random forest model resulted in the high spatial resolution prediction of Nepal’s national forest SOC stock together with prediction uncertainties. Our spatially explicit forest SOC map showed the high SOC levels in high-elevation forests and a significant underrepresentation of these stocks in global-scale assessments. Our results offer an improved baseline on the distribution of total carbon in the forests of the Central Himalayas. The benchmark maps of predicted forest SOC and associated errors, along with our estimate of 494 million tonnes (SE = 16) of total SOC in the topsoil (0–30 cm) of forested areas in Nepal, carry important implications for understanding the spatial variability of forest SOC in mountainous regions with complex terrains.
- Published
- 2023
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28. Information theoretical limits for quantum optimal control solutions: error scaling of noisy control channels
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Matthias M. Müller, Stefano Gherardini, Tommaso Calarco, Simone Montangero, and Filippo Caruso
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Medicine ,Science - Abstract
Abstract Accurate manipulations of an open quantum system require a deep knowledge of its controllability properties and the information content of the implemented control fields. By using tools of information and quantum optimal control theory, we provide analytical bounds (information-time bounds) to characterize our capability to control the system when subject to arbitrary sources of noise. Moreover, since the presence of an external noise field induces open quantum system dynamics, we also show that the results provided by the information-time bounds are in very good agreement with the Kofman–Kurizki universal formula describing decoherence processes. Finally, we numerically test the scaling of the control accuracy as a function of the noise parameters, by means of the dressed chopped random basis (dCRAB) algorithm for quantum optimal control.
- Published
- 2022
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29. Reduced CV risk with long-term GH replacement in AGHD: data from two large observational studies
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Charlotte Höybye, Beverly M K Biller, Jean-Marc Ferran, Murray B Gordon, Nicky Kelepouris, Navid Nedjatian, Anne H Olsen, and Matthias M Weber
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norditropin ,growth hormone ,cardiovascular risk ,nordinet ,answer ,Diseases of the endocrine glands. Clinical endocrinology ,RC648-665 - Abstract
Adult growth hormone deficiency (AGHD) is associated with an increased risk of cardiovascular (CV) disease. Long-term growth hormone (GH) trea tment could improve CV outcomes. The objective of this study was to evaluate CV disease risk in patients with AGHD who received GH replacement therapy for up to 10 years as part of NordiNet® IOS (NCT00960128) and the ANSWER Program (NCT01009905). The studies were observational, non-interventional and multicentre, monitoring l ong-term effectiveness and safety of GH treatment. NordiNet® IOS involved 23 countries (469 sites) across Europe and the Middle East. The ANSWER Program was conducted in the USA (207 sites). This analysis included patients aged 18–75 years who were GH na ïve at study entry, who had ≤10 years of GH treatment data and who could be assessed for CV risk for at least 1 follow-up year. The main outcome measure was risk of CV disea se by age 75 years, as calculated with the Multinational Cardiovascular Risk Consortium model (Brunner score) using non-high-density lipoprotein cholesterol adjusted for age, sex and CV risk factors. The results of this analysis showed that CV risk decreased gradually over the 10-year period for GH-treated patients. The risk was lower for patients treated for 2 and 7 years vs age- and sex-matched control groups (not yet started treatment) (14.51% vs 16.15%; P = 0.0105 and 13.53% vs 16.81%; P = 0.0001, respectively). This suggests that GH treatment in people with AGHD may reduce the risk of CV disease by age 75 years compared with matched controls.
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- 2022
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30. Canopy dieback and recovery in Australian native forests following extreme drought
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Adriano Losso, Anthea Challis, Alice Gauthey, Rachael H. Nolan, Samuel Hislop, Adam Roff, Matthias M. Boer, Mingkai Jiang, Belinda E. Medlyn, and Brendan Choat
- Subjects
Medicine ,Science - Abstract
Abstract In 2019, south-eastern Australia experienced its driest and hottest year on record, resulting in massive canopy dieback events in eucalypt dominated forests. A subsequent period of high precipitation in 2020 provided a rare opportunity to quantify the impacts of extreme drought and consequent recovery. We quantified canopy health and hydraulic impairment (native percent loss of hydraulic conductivity, PLC) of 18 native tree species growing at 15 sites that were heavily impacted by the drought both during and 8–10 months after the drought. Most species exhibited high PLC during drought (PLC:65.1 ± 3.3%), with no clear patterns across sites or species. Heavily impaired trees (PLC > 70%) showed extensive canopy browning. In the post-drought period, most surviving trees exhibited hydraulic recovery (PLC:26.1 ± 5.1%), although PLC remained high in some trees (50–70%). Regained hydraulic function (PLC
- Published
- 2022
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31. FireDrone: Multi‐Environment Thermally Agnostic Aerial Robot
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David Häusermann, Sam Bodry, Fabian Wiesemüller, Aslan Miriyev, Severin Siegrist, Fan Fu, Sabyasachi Gaan, Matthias M. Koebel, Wim J. Malfait, Shanyu Zhao, and Mirko Kovač
- Subjects
drone ,polyimide aerogel ,quadrotor ,temperature agnostic robot ,thermal insulation ,Computer engineering. Computer hardware ,TK7885-7895 ,Control engineering systems. Automatic machinery (General) ,TJ212-225 - Abstract
Deploying robots in extreme environments reduces risks to human lives. However, robot operating conditions are often limited by environmental factors such as extreme temperatures encountered in fire disasters or polar regions. Especially drones face challenges in carrying thermal management systems protecting vital components, due to limited payload capacity compared to ground robots. Herein, a thermally agnostic aerial robot comprising structural thermally insulating material and a phase change material cooling system, inspired by natural thermal regulation principles, is designed, modelled and experimentally validated. Building on the robot development paradigm of physical artificial intelligence, the concurrent development of materials and design enables the creation of novel physiologically adaptive systems. Polyimide aerogel is applied as one of the main structural materials in the drone's design to adapt the robot's structure and properties to extreme temperatures. Glass fiber reinforcement with silica aerogel particles reduces high‐temperature shrinkage and pore structure degradation after exposure to high temperatures and most of the composite aerogel features are preserved. A high technology‐readiness‐level drone prototype, allowing for operation in a broad range of ambient temperatures, is demonstrated. The proposed technology for thermally agnostic drones may unleash the great potential of aerial robotics in multiple industrial and research applications.
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- 2023
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32. A pilot study of cerebral metabolism and serotonin 5-HT2A receptor occupancy in rats treated with the psychedelic tryptamine DMT in conjunction with the MAO inhibitor harmine
- Author
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Klemens Egger, Frederik Gudmundsen, Naja Støckel Jessen, Christina Baun, Sandra N. Poetzsch, Vladimir Shalgunov, Matthias M. Herth, Boris B. Quednow, Chantal Martin-Soelch, Dario Dornbierer, Milan Scheidegger, Paul Cumming, and Mikael Palner
- Subjects
psychedelics ,ayahuasca ,pharmahuasca ,DMT ,harmine ,serotonin receptor ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Rationale: The psychedelic effects of the traditional Amazonian botanical decoction known as ayahuasca are often attributed to agonism at brain serotonin 5-HT2A receptors by N,N-dimethyltryptamine (DMT). To reduce first pass metabolism of oral DMT, ayahuasca preparations additionally contain reversible monoamine oxidase A (MAO-A) inhibitors, namely β-carboline alkaloids such as harmine. However, there is lacking biochemical evidence to substantiate this pharmacokinetic potentiation of DMT in brain via systemic MAO-A inhibition.Objectives: We measured the pharmacokinetic profile of harmine and/or DMT in rat brain, and tested for pharmacodynamic effects on brain glucose metabolism and DMT occupancy at brain serotonin 5-HT2A receptors.Methods: We first measured brain concentrations of harmine and DMT after treatment with harmine and/or DMT at low sub-cutaneous doses (1 mg/kg each) or harmine plus DMT at moderate doses (3 mg/kg each). In the same groups of rats, we also measured ex vivo the effects of these treatments on the availability of serotonin 5-HT2A receptors in frontal cortex. Finally, we explored effects of DMT and/or harmine (1 mg/kg each) on brain glucose metabolism with [18F]FDG-PET.Results: Results confirmed that co-administration of harmine inhibited the formation of the DMT metabolite indole-3-acetic acid (3-IAA) in brain, while correspondingly increasing the cerebral availability of DMT. However, we were unable to detect any significant occupancy by DMT at 5-HT2A receptors measured ex vivo, despite brain DMT concentrations as high as 11.3 µM. We did not observe significant effects of low dose DMT and/or harmine on cerebral [18F]FDG-PET uptake.Conclusion: These preliminary results call for further experiments to establish the dose-dependent effects of harmine/DMT on serotonin receptor occupancy and cerebral metabolism.
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- 2023
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33. A Review of Leaf-Level Flammability Traits in Eucalypt Trees
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Nicolas Younes, Marta Yebra, Matthias M. Boer, Anne Griebel, and Rachael H. Nolan
- Subjects
fire ,ignition ,combustion ,fuel moisture content ,leaf morphology ,dry matter content ,Physics ,QC1-999 - Abstract
With more frequent and intense fires expected under future climate conditions, it is important to understand the mechanisms that control flammability in Australian forests. We followed a systematic review approach to determine which physical traits make eucalypts leaves more or less flammable. Specifically, we reviewed 20 studies that covered 35 eucalypt species across five countries and found that leaf water content, leaf area (LA), and specific leaf area (SLA) are the main drivers of leaf flammability. These traits are easy and straightforward to measure, while more laborious traits (e.g., volatile organic compounds and structural carbohydrates) are seldom measured and reported. Leaf flammability also varies with species, and, while the biochemistry plays a role in how leaves burn, it plays a minor role in fire behaviour at landscape scales. This review highlights the range of different protocols used to measure flammability and leaf water content, warranting caution when comparing traits and results between studies. As a result, we propose a standardised protocol to measure leaf water content and advocate for long-term measurements of leaf traits and flammability. This study not only contributes to the understanding of how and why eucalypt leaves burn but also encourages research into the relative importance of traits in influencing flammability and provides a guide for selecting traits that can be monitored using satellite images to inform fire management policies and strategies.
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- 2024
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34. Severe and Short Interval Fires Rearrange Dry Forest Fuel Arrays in South-Eastern Australia
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Christopher E. Gordon, Rachael H. Nolan, Matthias M. Boer, Eli R. Bendall, Jane S. Williamson, Owen F. Price, Belinda J. Kenny, Jennifer E. Taylor, Andrew J. Denham, and Ross A. Bradstock
- Subjects
fire interval ,fuel severity ,fire regime ,fuel ,Sydney Basin Bioregion ,Physics ,QC1-999 - Abstract
Fire regimes have shaped extant vegetation communities, and subsequently fuel arrays, in fire-prone landscapes. Understanding how resilient fuel arrays are to fire regime attributes will be key for future fire management actions, given global fire regime shifts. We use a network of 63-field sites across the Sydney Basin Bioregion (Australia) to quantify how fire interval (short: last three fires 10 years apart) and severity (low: understorey canopy scorched, high: understorey and overstorey canopy scorched), impacted fuel attribute values 2.5 years after Australia’s 2019–2020 Black Summer fires. Tree bark fuel hazard, herbaceous (near-surface fuels; grasses, sedges
- Published
- 2024
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35. Fundus Autofluorescence in Posterior and Panuveitis—An Under-Estimated Imaging Technique: A Review and Case Series
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Matthias M. Mauschitz, Markus Zeller, Pradeep Sagar, Suchitra Biswal, Gabriela Guzman, Jan H. Terheyden, Carsten H. Meyer, Frank G. Holz, Carsten Heinz, Uwe Pleyer, Robert P. Finger, and Maximilian W. M. Wintergerst
- Subjects
biomarker ,FAF ,fundus autofluorescence ,inflammation ,uveitis ,Microbiology ,QR1-502 - Abstract
Fundus autofluorescence (FAF) is a prompt and non-invasive imaging modality helpful in detecting pathological abnormalities within the retina and the choroid. This narrative review and case series provides an overview on the current application of FAF in posterior and panuveitis. The literature was reviewed for articles on lesion characteristics on FAF of specific posterior and panuveitis entities as well as benefits and limitations of FAF for diagnosing and monitoring disease. FAF characteristics are described for non-infectious and infectious uveitis forms as well as masquerade syndromes. Dependent on the uveitis entity, FAF is of diagnostic value in detecting disease and following the clinical course. Currently available FAF modalities which differ in excitation wavelengths can provide different pathological insights depending on disease entity and activity. Further studies on the comparison of FAF modalities and their individual value for uveitis diagnosis and monitoring are warranted.
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- 2024
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36. Forest fire threatens global carbon sinks and population centres under rising atmospheric water demand
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Hamish Clarke, Rachael H. Nolan, Victor Resco De Dios, Ross Bradstock, Anne Griebel, Shiva Khanal, and Matthias M. Boer
- Subjects
Science - Abstract
Rising forest flammability could become a major public health issue and amplify climate change via feedbacks on the carbon cycle. Here the authors identify daily fuel moisture thresholds associated with increased fire risk in earth’s forests.
- Published
- 2022
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37. Imaging features of intraductal tubulopapillary neoplasm of the pancreas and its differentiation from conventional pancreatic ductal adenocarcinoma
- Author
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Ekaterina Khristenko, Thomas Hank, Matthias M. Gaida, Hans-Ulrich Kauczor, Thilo Hackert, Miriam Klauß, and Philipp Mayer
- Subjects
Medicine ,Science - Abstract
Abstract Intraductal tubulopapillary neoplasms (ITPN) are rare pancreatic tumors (
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- 2022
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38. Implementation of deep learning in liver pathology optimizes diagnosis of benign lesions and adenocarcinoma metastasis
- Author
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Mark Kriegsmann, Katharina Kriegsmann, Georg Steinbuss, Christiane Zgorzelski, Thomas Albrecht, Stefan Heinrich, Stefan Farkas, Wilfried Roth, Hien Dang, Anne Hausen, and Matthias M. Gaida
- Subjects
artificial intelligence ,deep learning ,liver metastasis ,liver pathology ,personalized medicine ,Medicine (General) ,R5-920 - Abstract
Abstract Introduction Differentiation of histologically similar structures in the liver, including anatomical structures, benign bile duct lesions, or common types of liver metastases, can be challenging with conventional histological tissue sections alone. Accurate histopathological classification is paramount for the diagnosis and adequate treatment of the disease. Deep learning algorithms have been proposed for objective and consistent assessment of digital histopathological images. Materials and methods In the present study, we trained and evaluated deep learning algorithms based on the EfficientNetV2 and ResNetRS architectures to discriminate between different histopathological classes. For the required dataset, specialized surgical pathologists annotated seven different histological classes, including different non‐neoplastic anatomical structures, benign bile duct lesions, and liver metastases from colorectal and pancreatic adenocarcinoma in a large patient cohort. Annotation resulted in a total of 204.159 image patches, followed by discrimination analysis using our deep learning models. Model performance was evaluated on validation and test data using confusion matrices. Results Evaluation of the test set based on tiles and cases revealed overall highly satisfactory prediction capability of our algorithm for the different histological classes, resulting in a tile accuracy of 89% (38 413/43 059) and case accuracy of 94% (198/211). Importantly, the separation of metastasis versus benign lesions was certainly confident on case level, confirming the classification model performed with high diagnostic accuracy. Moreover, the whole curated raw data set is made publically available. Conclusions Deep learning is a promising approach in surgical liver pathology supporting decision making in personalized medicine.
- Published
- 2023
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39. Combined Application of a Novel Robotic System and Exoscope for Microsurgical Anastomoses: Preclinical Performance
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Kai J. Wessel, Isa Wendenburg, Shaghayegh Gorji, Alexander Dermietzel, Matthias M. Aitzetmueller, Charalampos Varnava, Philipp Wiebringhaus, Marie-Luise Klietz, Tobias Hirsch, and Maximilian Kueckelhaus
- Subjects
robotics ,microsurgery ,anastomosis ,learning curve ,ergonomics ,Surgery ,RD1-811 - Abstract
Background The concept of robotic microsurgery is becoming increasingly known as several robotic systems tailored to the specific needs of microsurgery are being introduced. Training with these devices is essential to draw conclusions about their potential clinical utility. This study describes the training and learning curve of experienced microsurgeons and complete novices using such a robotic surgical system in combination with an exoscope.
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- 2023
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40. Recommendations on the structure, personal, and organization of intensive care units
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Christian Waydhas, Reimer Riessen, Andreas Markewitz, Florian Hoffmann, Lorenz Frey, Bernd W. Böttiger, Sebastian Brenner, Thorsten Brenner, Teresa Deffner, Matthias M. Deininger, Uwe Janssens, Stefan Kluge, Gernot Marx, Stefan Schwab, Andreas W. Unterberg, Felix Walcher, and Thomas van den Hooven
- Subjects
intensive care medicine ,personal ,organization ,structural requirements ,quality of care ,recommendation ,Medicine (General) ,R5-920 - Abstract
BackgroundIntensive care units (ICU) are central facilities of medical care in hospitals world-wide and pose a significant financial burden on the health care system.ObjectivesTo provide guidance and recommendations for the requirements of (infra)structure, personal, and organization of intensive care units.Design and settingDevelopment of recommendations based on a systematic literature search and a formal consensus process from a group of multidisciplinary and multiprofessional specialists from the German Interdisciplinary Association of Intensive Care and Emergency Medicine (DIVI). The grading of the recommendation follows the report from an American College of Chest Physicians Task Force.ResultsThe recommendations cover the fields of a 3-staged level of intensive care units, a 3-staged level of care with respect to severity of illness, qualitative and quantitative requirements of physicians and nurses as well as staffing with physiotherapists, pharmacists, psychologists, palliative medicine and other specialists, all adapted to the 3 levels of ICUs. Furthermore, proposals concerning the equipment and the construction of ICUs are supplied.ConclusionThis document provides a detailed framework for organizing and planning the operation and construction/renovation of ICUs.
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- 2023
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41. Implementing strabismus-specific psychosocial questionnaires in everyday clinical practice: mental health and quality of life in the context of strabismus surgery
- Author
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Matthias M Mauschitz, Bettina Wabbels, and Maja Ehlers
- Subjects
Ophthalmology ,RE1-994 - Abstract
Background Strabismus can have a great negative impact on the quality of life and the well-being of affected patients. In the past, these aspects were often neglected and, compared with somatic functioning, placed in the background. The aim of our study is to elicit factors influencing satisfaction with strabismus surgery, quality of life and expectations of surgery in order to better predict who will benefit the most and who may need further support.Methods We made a selection of suitable questionnaires to assess psychosocial aspects of strabismus and decided for Adult Strabismus 20 Questionnaire, Amblyopia and Strabismus Questionnaire, Diplopia Questionnaire, Expectations of Strabismus Surgery Questionnaire and Hospital Anxiety and Depression Scale. We then translated these measures (if not available in German). The patients filled out these forms as part of their preoperative orthoptic and ophthalmological assessment as well as approximately 3 months after strabismus surgery.Results We enrolled 59 patients in this study. Postoperative strabismus-related quality of life was higher after surgery and anxiety and depression levels were lower. Satisfaction with surgery was lower with higher postoperative angle and diplopia; the latter was also a determinant of lower postoperative quality of life. Higher expectations of strabismus surgery were present with higher depression levels and higher preoperative strabismus angle.Conclusion Our data indicate that strabismus surgery may cause a significant improvement in several psychosocial domains. There is evidence that psychosocial factors can have significant impact on expectations with surgery. Hence, it is important to consider mental health aspects of this disease in order to treat patients in the best possible way.
- Published
- 2023
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42. The 2019–2020 Australian forest fires are a harbinger of decreased prescribed burning effectiveness under rising extreme conditions
- Author
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Hamish Clarke, Brett Cirulis, Trent Penman, Owen Price, Matthias M. Boer, and Ross Bradstock
- Subjects
Medicine ,Science - Abstract
Abstract There is an imperative for fire agencies to quantify the potential for prescribed burning to mitigate risk to life, property and environmental values while facing changing climates. The 2019–2020 Black Summer fires in eastern Australia raised questions about the effectiveness of prescribed burning in mitigating risk under unprecedented fire conditions. We performed a simulation experiment to test the effects of different rates of prescribed burning treatment on risks posed by wildfire to life, property and infrastructure. In four forested case study landscapes, we found that the risks posed by wildfire were substantially higher under the fire weather conditions of the 2019–2020 season, compared to the full range of long-term historic weather conditions. For area burnt and house loss, the 2019–2020 conditions resulted in more than a doubling of residual risk across the four landscapes, regardless of treatment rate (mean increase of 230%, range 164–360%). Fire managers must prepare for a higher level of residual risk as climate change increases the likelihood of similar or even more dangerous fire seasons.
- Published
- 2022
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43. Fire activity as measured by burned area reveals weak effects of ENSO in China
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Víctor Resco de Dios, Yinan Yao, Àngel Cunill Camprubí, and Matthias M. Boer
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Science - Published
- 2022
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44. Effect of Drug Loading in Mesoporous Silica on Amorphous Stability and Performance
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Christoffer G. Bavnhøj, Matthias M. Knopp, and Korbinian Löbmann
- Subjects
mesoporous silica ,loading capacity ,dissolution ,long-term stability ,differential scanning calorimetry (DSC) ,poorly soluble drugs ,Pharmacy and materia medica ,RS1-441 - Abstract
The encapsulation of drugs within mesoporous silica (MS) has for several years been a subject of research. Previous studies proposed that drug loadings up to the monomolecular loading capacity (MLC) are the optimal choice for maintaining the drug in an amorphous form, whereas filling the pores above the monolayer and up to the pore filling capacity (PFC) may introduce some physical instabilities. The aim of this study was to assess the effect of drug loading in MS-based amorphous formulations on the stability of the amorphous form of the drug as well as the dissolution. In particular, the following drug loadings were investigated: below MLC, at MLC, between MLC and PFC and at PFC. The drug-loaded MS formulations were analyzed directly after preparation and after 18 months of storage under accelerated conditions (40 °C in both dry and humid conditions). The MLC and PFC for the drug celecoxib (CEL) on the MS ParteckSLC500 (SLC) were determined at 33.5 wt.% and 48.4 wt.%, respectively. This study found that SLC can effectively preserve the amorphous form of the drug for 18 months, provided that the loading is below the PFC (max, Tmax and dissolution rate.
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- 2024
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45. Elevated microsatellite instability at selected tetranucleotide (EMAST) repeats in gastric cancer: a distinct microsatellite instability type with potential clinical impact?
- Author
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Anna‐Lina Herz, Sarah Wisser, Meike Kohlruss, Julia Slotta‐Huspenina, Moritz Jesinghaus, Bianca Grosser, Katja Steiger, Alexander Novotny, Alexander Hapfelmeier, Thomas Schmidt, Matthias M Gaida, Wilko Weichert, and Gisela Keller
- Subjects
EMAST ,microsatellite instability ,gastric adenocarcinoma ,neoadjuvant chemotherapy ,prognosis ,Pathology ,RB1-214 - Abstract
Abstract We investigated the clinical impact of elevated microsatellite instability at selected tetranucleotide (EMAST) repeats in the context of neoadjuvant chemotherapy (CTx) in gastric/gastro‐oesophageal adenocarcinomas. We analysed 583 resected tumours (272 without and 311 after CTx) and 142 tumour biopsies before CTx. If at least two or three of the five tetranucleotide repeat markers tested showed instability, the tumours were defined as EMAST (2+) or EMAST (3+), respectively. Expression of mismatch repair proteins including MSH3 was analysed using immunohistochemistry. Microsatellite instability (MSI) and Epstein–Barr virus (EBV) positivity were determined using standard assays. EMAST (2+) and (3+) were detected in 17.8 and 11.5% of the tumours, respectively. The frequency of EMAST (2+) or (3+) in MSI‐high (MSI‐H) tumours was 96.2 or 92.5%, respectively, demonstrating a high overlap with this molecular subtype, and the association of EMAST and MSI status was significant (each overall p
- Published
- 2022
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46. A Forgotten Entity following Breast Implant Contracture: Does Baker Need a Change?
- Author
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Andrea Pagani, Matthias M. Aitzetmüller, and Lorenz Larcher
- Subjects
breast implants ,capsular calcification ,baker score ,breast surgery ,implant surface ,Surgery ,RD1-811 - Abstract
Although capsular contracture represents one of the most important complications after breast augmentation, local inflammation and fibrosis can lead, in very rare cases, to capsular calcification, an often-forgotten radiological sign of capsular contracture. In this article, the authors present a clinical case of breast implant calcification in an 81-year-old patient. Although this complication has been rarely described, the literature was reviewed to clarify the role of the local microenvironment in capsular contracture and calcification. At present, capsular contracture patients are classified using the conventional Baker score and the histological Wilflingseder classification. As it was not possible to consider capsular calcification when classifying our patient using the traditional scores, the authors propose an updated version of the current scale.
- Published
- 2022
- Full Text
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47. Neurofilament light chain and retinal layers' determinants and association: A population‐based study
- Author
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Davide Garzone, Robert P. Finger, Matthias M. Mauschitz, Marina L. S. Santos, Monique M. B. Breteler, and N. Ahmad Aziz
- Subjects
Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Both retinal atrophy measured through optical coherence tomography and plasma neurofilament light chain (NfL) levels are markers of neurodegeneration, but their relationship is unknown. Therefore, we assessed their determinants and association in 4369 participants of a population‐based study. Both plasma NfL levels and inner retinal atrophy increased exponentially with age. In the presence of risk factors for neurodegeneration (including age, smoking, and a history of neurological disorders), plasma NfL levels were associated with inner retinal atrophy and outer retinal thickening. Our findings indicate that inner retinal atrophy can reflect neuroaxonal damage as mirrored by rising plasma NfL levels.
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- 2022
- Full Text
- View/download PDF
48. Mathematical modelling identifies conditions for maintaining and escaping feedback control in the intestinal epithelium
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Matthias M. Fischer, Hanspeter Herzel, and Nils Blüthgen
- Subjects
Medicine ,Science - Abstract
Abstract The intestinal epithelium is one of the fastest renewing tissues in mammals. It shows a hierarchical organisation, where intestinal stem cells at the base of crypts give rise to rapidly dividing transit amplifying cells that in turn renew the pool of short-lived differentiated cells. Upon injury and stem-cell loss, cells can also de-differentiate. Tissue homeostasis requires a tightly regulated balance of differentiation and stem cell proliferation, and failure can lead to tissue extinction or to unbounded growth and cancerous lesions. Here, we present a two-compartment mathematical model of intestinal epithelium population dynamics that includes a known feedback inhibition of stem cell differentiation by differentiated cells. The model shows that feedback regulation stabilises the number of differentiated cells as these become invariant to changes in their apoptosis rate. Stability of the system is largely independent of feedback strength and shape, but specific thresholds exist which if bypassed cause unbounded growth. When dedifferentiation is added to the model, we find that the system can recover faster after certain external perturbations. However, dedifferentiation makes the system more prone to losing homeostasis. Taken together, our mathematical model shows how a feedback-controlled hierarchical tissue can maintain homeostasis and can be robust to many external perturbations.
- Published
- 2022
- Full Text
- View/download PDF
49. Substantiate a read-across hypothesis by using transcriptome data—A case study on volatile diketones
- Author
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Christina Drake, Matthias M. Wehr, Walter Zobl, Jeannette Koschmann, David De Lucca, Britta A. Kühne, Tanja Hansen, Jan Knebel, Detlef Ritter, Jan Boei, Harry Vrieling, Annette Bitsch, and Sylvia E. Escher
- Subjects
read across ,new approach methodology ,transcriptomics ,TempO-seq ,PBEC ,protein network analysis ,Toxicology. Poisons ,RA1190-1270 - Abstract
This case study explores the applicability of transcriptome data to characterize a common mechanism of action within groups of short-chain aliphatic α-, β-, and γ-diketones. Human reference in vivo data indicate that the α-diketone diacetyl induces bronchiolitis obliterans in workers involved in the preparation of microwave popcorn. The other three α-diketones induced inflammatory responses in preclinical in vivo animal studies, whereas beta and gamma diketones in addition caused neuronal effects. We investigated early transcriptional responses in primary human bronchiolar (PBEC) cell cultures after 24 h and 72 h of air-liquid exposure. Differentially expressed genes (DEGs) were assessed based on transcriptome data generated with the EUToxRisk gene panel of Temp-O-Seq®. For each individual substance, genes were identified displaying a consistent differential expression across dose and exposure duration. The log fold change values of the DEG profiles indicate that α- and β-diketones are more active compared to γ-diketones. α-diketones in particular showed a highly concordant expression pattern, which may serve as a first indication of the shared mode of action. In order to gain a better mechanistic understanding, the resultant DEGs were submitted to a pathway analysis using ConsensusPathDB. The four α-diketones showed very similar results with regard to the number of activated and shared pathways. Overall, the number of signaling pathways decreased from α-to β-to γ-diketones. Additionally, we reconstructed networks of genes that interact with one another and are associated with different adverse outcomes such as fibrosis, inflammation or apoptosis using the TRANSPATH-database. Transcription factor enrichment and upstream analyses with the geneXplain platform revealed highly interacting gene products (called master regulators, MRs) per case study compound. The mapping of the resultant MRs on the reconstructed networks, visualized similar gene regulation with regard to fibrosis, inflammation and apoptosis. This analysis showed that transcriptome data can strengthen the similarity assessment of compounds, which is of particular importance, e.g., in read-across approaches. It is one important step towards grouping of compounds based on biological profiles.
- Published
- 2023
- Full Text
- View/download PDF
50. Morphology-guided transcriptomic analysis of human pancreatic cancer organoids reveals microenvironmental signals that enhance invasion
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Yea Ji Jeong, Hildur Knutsdottir, Fatemeh Shojaeian, Michael G. Lerner, Maria F. Wissler, Elodie Henriet, Tammy Ng, Shalini Datta, Bernat Navarro-Serer, Peter Chianchiano, Benedict Kinny-Köster, Jacquelyn W. Zimmerman, Genevieve Stein-O’Brien, Matthias M. Gaida, James R. Eshleman, Ming-Tseh Lin, Elana J. Fertig, Andrew J. Ewald, Joel S. Bader, and Laura D. Wood
- Subjects
Gastroenterology ,Oncology ,Medicine - Abstract
Pancreatic ductal adenocarcinoma (PDAC) frequently presents with metastasis, but the molecular programs in human PDAC cells that drive invasion are not well understood. Using an experimental pipeline enabling PDAC organoid isolation and collection based on invasive phenotype, we assessed the transcriptomic programs associated with invasion in our organoid model. We identified differentially expressed genes in invasive organoids compared with matched noninvasive organoids from the same patients, and we confirmed that the encoded proteins were enhanced in organoid invasive protrusions. We identified 3 distinct transcriptomic groups in invasive organoids, 2 of which correlated directly with the morphological invasion patterns and were characterized by distinct upregulated pathways. Leveraging publicly available single-cell RNA-sequencing data, we mapped our transcriptomic groups onto human PDAC tissue samples, highlighting differences in the tumor microenvironment between transcriptomic groups and suggesting that non-neoplastic cells in the tumor microenvironment can modulate tumor cell invasion. To further address this possibility, we performed computational ligand-receptor analysis and validated the impact of multiple ligands (TGF-β1, IL-6, CXCL12, MMP9) on invasion and gene expression in an independent cohort of fresh human PDAC organoids. Our results identify molecular programs driving morphologically defined invasion patterns and highlight the tumor microenvironment as a potential modulator of these programs.
- Published
- 2023
- Full Text
- View/download PDF
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