156 research outputs found

    Investigation of the Electrodeposition Parameters on the Coating Process on Open Porous Media

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    Porous materials such as bones, sponges or cork are used in nature due to their light weight. Metal foams with stochastically distributed pores are such a porous bionic material based on nature. Their low weight and mechanical properties make them perfect for use in aerospace, automotive and building construction industry. To improve the mechanical properties, hybrid metal foams are produced consisting of a substrate foam with a coating applied by electrodeposition. An electrochemical coating cell consists of a positively charged anode and a negatively charged cathode. The metal of the anode is oxidised to a positively charged cation and electrons. The cation moves through the electrolyte to the cathode, where it is reduced back to the metal and electrons are consumed. Due to this process the cathode is coated with the anode material. The mass transport during the electroplating process can be divided into four parts: Convection, diffusion, migration and reaction. Convection is a forced flow, e.g. by pumping. Diffusion describes the movement caused by concentration gradients and the migration is the movement by an electric field. Reaction is the ion consumption at the cathode during the electrodeposition process and is therefore called sink. During the electrodeposition process, coating thickness inhomogeneities occur due to mass transport limitations [2,4] and lead to non‐uniform mechanical properties within the coated foams. These inhomogeneties motivate an investigation of the electrodeposition process and its parameters

    Regionalized tissue fluidization is required for epithelial gap closure during insect gastrulation

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    Many animal embryos pull and close an epithelial sheet around the ellipsoidal egg surface during a gastrulation process known as epiboly. The ovoidal geometry dictates that the epithelial sheet first expands and subsequently compacts. Moreover, the spreading epithelium is mechanically stressed and this stress needs to be released. Here we show that during extraembryonic tissue (serosa) epiboly in the insect Tribolium castaneum, the non-proliferative serosa becomes regionalized into a solid-like dorsal region with larger non-rearranging cells, and a more fluid-like ventral region surrounding the leading edge with smaller cells undergoing intercalations. Our results suggest that a heterogeneous actomyosin cable contributes to the fluidization of the leading edge by driving sequential eviction and intercalation of individual cells away from the serosa margin. Since this developmental solution utilized during epiboly resembles the mechanism of wound healing, we propose actomyosin cable-driven local tissue fluidization as a conserved morphogenetic module for closure of epithelial gaps

    Reprint of “Chordoma in children: Case-report and review of literature”

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    We report an exceptional case of a very late local failure in a 9-year-old boy presenting with a chordoma of the cranio-cervical junction. The child was initially treated with a combination of surgical resection followed by high dose photon–proton radiation therapy. This aggressive therapy allowed a 9-year remission with minimal side-effects. Unfortunately, he subsequently presented with a local failure managed with a second full-dose course of protons. The child died one year later from local bleeding of unclear etiology

    Clinical, radiologic, pathologic, and molecular characteristics of long-term survivors of diffuse intrinsic pontine glioma (DIPG): a collaborative report from the International and European Society for Pediatric Oncology DIPG registries

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    Purpose Diffuse intrinsic pontine glioma (DIPG) is a brainstem malignancy with a median survival of < 1 year. The International and European Society for Pediatric Oncology DIPG Registries collaborated to compare clinical, radiologic, and histomolecular characteristics between short-term survivors (STSs) and long-term survivors (LTSs). Materials and Methods Data abstracted from registry databases included patients from North America, Australia, Germany, Austria, Switzerland, the Netherlands, Italy, France, the United Kingdom, and Croatia. Results Among 1,130 pediatric and young adults with radiographically confirmed DIPG, 122 (11%) were excluded. Of the 1,008 remaining patients, 101 (10%) were LTSs (survival ≥ 2 years). Median survival time was 11 months (interquartile range, 7.5 to 16 months), and 1-, 2-, 3-, 4-, and 5-year survival rates were 42.3% (95% CI, 38.1% to 44.1%), 9.6% (95% CI, 7.8% to 11.3%), 4.3% (95% CI, 3.2% to 5.8%), 3.2% (95% CI, 2.4% to 4.6%), and 2.2% (95% CI, 1.4% to 3.4%), respectively. LTSs, compared with STSs, more commonly presented at age < 3 or > 10 years (11% v 3% and 33% v 23%, respectively; P < .001) and with longer symptom duration ( P < .001). STSs, compared with LTSs, more commonly presented with cranial nerve palsy (83% v 73%, respectively; P = .008), ring enhancement (38% v 23%, respectively; P = .007), necrosis (42% v 26%, respectively; P = .009), and extrapontine extension (92% v 86%, respectively; P = .04). LTSs more commonly received systemic therapy at diagnosis (88% v 75% for STSs; P = .005). Biopsies and autopsies were performed in 299 patients (30%) and 77 patients (10%), respectively; 181 tumors (48%) were molecularly characterized. LTSs were more likely to harbor a HIST1H3B mutation (odds ratio, 1.28; 95% CI, 1.1 to 1.5; P = .002). Conclusion We report clinical, radiologic, and molecular factors that correlate with survival in children and young adults with DIPG, which are important for risk stratification in future clinical trials

    Optimising biomarkers for accurate ependymoma diagnosis, prognostication and stratification within International Clinical Trials: A BIOMECA study

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    BACKGROUND: Accurate identification of brain tumour molecular subgroups is increasingly important. We aimed to establish the most accurate and reproducible ependymoma subgroup biomarker detection techniques, across 147 cases from International Society of Pediatric Oncology (SIOP) Ependymoma II trial participants, enrolled in the pan-European "Biomarkers of Ependymoma in Children and Adolescents (BIOMECA)" study. METHODS: Across six European BIOMECA laboratories we evaluated epigenetic profiling (DNA methylation array); immunohistochemistry (IHC) for nuclear p65-RELA, H3K27me3, and Tenascin-C; copy number analysis via FISH and MLPA (1q, CDKN2A), and MIP and DNA methylation array (genome-wide copy number evaluation); analysis of ZFTA- and YAP1-fusions by RT-PCR and sequencing, Nanostring and break-apart FISH. RESULTS: DNA Methylation profiling classified 65.3% (n=96/147) of cases as EPN-PFA and 15% (n=22/147) as ST-ZFTA fusion-positive. Immunohistochemical loss of H3K27me3 was a reproducible and accurate surrogate marker for EPN-PFA (sensitivity 99-100% across three centres). IHC for p65-RELA, FISH, and RNA-based analyses effectively identified ZFTA- and YAP1- fused supratentorial ependymomas. Detection of 1q gain using FISH exhibited only 57% inter-centre concordance and low sensitivity and specificity whilst MIP, MLPA and DNA methylation-based approaches demonstrated greater accuracy. CONCLUSIONS: We confirm, in a prospective trial cohort, that H3K27me3 immunohistochemistry is a robust EPN-PFA biomarker. Tenascin-C should be abandoned as a PFA marker. DNA methylation and MIP arrays are effective tools for copy number analysis of 1q gain, 6q and CDKN2A loss whilst FISH is inadequate. Fusion detection was successful, but rare novel fusions need more extensive technologies. Finally, we propose test sets to guide future diagnostic approaches

    Molecular, pathological, radiological, and immune profiling of non-brainstem pediatric high-grade glioma from the HERBY phase II randomized trial

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    The HERBY trial was a phase II open-label, randomized, multicenter trial evaluating bevacizumab (BEV) in addition to temozolomide/radiotherapy in patients with newly diagnosed non-brainstem high-grade glioma (HGG) between the ages of 3 and 18 years. We carried out comprehensive molecular analysis integrated with pathology, radiology, and immune profiling. In post-hoc subgroup analysis, hypermutator tumors (mismatch repair deficiency and somatic POLE/POLD1 mutations) and those biologically resembling pleomorphic xanthoastrocytoma ([PXA]-like, driven by BRAF_V600E or NF1 mutation) had significantly more CD8+ tumor-infiltrating lymphocytes, and longer survival with the addition of BEV. Histone H3 subgroups (hemispheric G34R/V and midline K27M) had a worse outcome and were immune cold. Future clinical trials will need to take into account the diversity represented by the term ‘‘HGG’’ in the pediatric population

    Reinventing ‘Many Voices’: MacBride and a Digital New World Information and Communication Order

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    The MacBride Commission Report was arguably one of the most significant multilateral interventions in the history of international communication. This article charts its emergence at the time of deeply contested Cold War politics, coinciding with the rise of the southern voices in the global arena, led by the non-aligned nations. Thirty-five years after the report's publication, has the global media evolved into a more democratic system, demonstrating greater diversity of views and viewpoints? Despite the still formidable power of US-led western media, the article suggests that the globalisation and digitisation of communication has contributed to a multi-layered and more complex global media scene, demonstrating the “rise of the rest”

    Calorie seeking, but not hedonic response, contributes to hyperphagia in a mouse model for Prader-Willi syndrome

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    Prader–Willi syndrome (PWS) is a neurodevelopmental disorder caused by deletion or inactivation of paternally expressed imprinted genes on human chromosome 15q11-q13, the most recognised feature of which is hyperphagia. This is thought to arise as a consequence of abnormalities in both the physiological drive for food and the rewarding properties of food. Although a number of mouse models for PWS exist, the underlying variables dictating maladaptive feeding remain unknown. Here, feeding behaviour in a mouse model in which the imprinting centre (IC) of the syntenic PWS interval has been deleted (PWSICdel mice) is characterised. It is demonstrated that PWSICdel mice show hyperghrelinaemia and increased consumption of food both following overnight fasting and when made more palatable with sucrose. However, hyperphagia in PWSICdel mice was not accompanied by any changes in reactivity to the hedonic properties of palatable food (sucrose or saccharin), as measured by lick-cluster size. Nevertheless, overall consumption by PWSICdel mice for non-caloric saccharin in the licking test was significantly reduced. Combined with converging findings from a continuous reinforcement schedule, these data indicate that PWSICdel mice show a marked heightened sensitivity to the calorific value of food. Overall, these data indicate that any impact of the rewarding properties of food on the hyperphagia seen in PWSICdel mice is driven primarily by calorie content and is unlikely to involve hedonic processes. This has important implications for understanding the neural systems underlying the feeding phenotype of PWS and the contribution of imprinted genes to abnormal feeding behaviour more generally
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