Tumour progression or pseudoprogression?:A review of post-treatment radiological appearances of glioblastoma

Glioblastoma (GBM) is a common brain tumour in adults, which, despite multimodality treatment, has a poor median survival. Efficacy of therapy is assessed by clinical examination and magnetic resonance imaging (MRI) features. There is now a recognised subset of treated patients with imaging features that indicate "progressive disease" according to Macdonald's criteria, but subsequently, show stabilisation or resolution without a change in treatment. In these cases of "pseudoprogression", it is believed that non-tumoural causes lead to increased contrast enhancement and conventional MRI is inadequate in distinguishing this from true tumour progression. Incorrect diagnosis is important, as failure to identify pseudoprogression could lead to an inappropriate change of effective therapy. The purpose of this review is to outline the current research into radiological assessment with MRI and molecular imaging of post-treatment GBMs, specifically the differentiation between pseudoprogression and tumour progression

Glioma imaging in Europe: A survey of 220 centres and recommendations for best clinical practice

Objectives: At a European Society of Neuroradiology (ESNR) Annual Meeting 2015 workshop, commonalities in practice, current controversies and technical hurdles in glioma MRI were discussed. We aimed to formulate guidance on MRI of glioma and determine its feasibility, by seeking information on glioma imaging practices from the European Neuroradiology community. Methods: Invitations to a structured survey were emailed to ESNR members (n=1,662) and associates (n=6,400), European national radiologists’ societies and distributed via social media. Results: Responses were received from 220 institutions (59% academic). Conventional imaging protocols generally include T2w, T2-FLAIR, DWI, and pre- and post-contrast T1w. Perfusion MRI is used widely (85.5%), while spectroscopy seems reserved for specific indications. Reasons for omitting advanced imaging modalities include lack of facility/software, time constraints and no requests. Early postoperative MRI is routinely carried out by 74% within 24–72 h, but only 17% report a percent measure of resection. For follow-up, most sites (60%) issue qualitative reports, while 27% report an assessment according to the RANO criteria. A minori

Stress responses in alfalfa (Medicago sativa L.) XIX. Transcriptional activation of oxidative pentose phosphate pathway genes at the onset of the isoflavonoid phytoalexin response

Article on stress responses in alfalfa (Medicago sativa L.) XIX and transcriptional activation of oxidative pentose phosphate pathway genes at the onset of the isoflavonoid phytoalexin response

Single NdPc2_{2} molecules on surfaces : adsorption, interaction, and molecular magnetism

Single molecule magnets (SMMs) play an important role in the field of molecular spintronics.They have huge potential for application in molecular-spin-transistors, molecular-spinvalves,and molecular quantum computing. SMMs are characterized by high spin groundstates with zero-field splitting leading to high relaxation barriers and long relaxation times.A relevant class of molecules are the lanthanide double-decker phthalocyanines (LaPc$_{2}$)with only one metal atom sandwiched between two organic phthalocyanine (Pc) ligands. For envisaged spintronic applications it is important to understand the interaction between the molecules and the substrate and its influence on the electronic and magnetic properties. The subject of this thesis is the investigation of the adsorbed neodymium double-decker phthalocyanine (NdPc$_{2}$) by means of low temperature scanning tunneling microscopy and spectroscopy (STM and STS). The molecules are deposited by sublimation onto different substrates. It is observed that a large fraction of the double-decker molecules decomposes during deposition. The decomposition probability strongly depends on the chosen substrate. Therefore it is concluded that the substrate modifies the electronic structure of the molecule leading to a stabilization or destabilization of the molecular entity. Charge transfer from the surface tothe molecule is identified as a potential stabilizing mechanism. The electronic and magnetic properties are investigated in detail for adsorbed NdPc$_{2}$ molecules on Cu(100). The results of the experimental study are compared to state-of the-art density functional theory calculations performed by our colleagues from the Peter Grünberg Institute (PGI-1) at the Forschungszentrum Jülich. Interestingly, the lower Pc ring of the molecule hybridizes intensely with the substrate leading to strong chemisorption of the molecule, while the upper Pc ring keeps its molecular type electronic states, which can be energetically shifted by an external electric field. Importantly, it is possible to get direct access to the spin-polarized 4$\textit{f}$-states of the central Nd ion by means of STM and STS. This important and unique characteristic absent for late lanthanide double-decker phthalocyanine molecules opens the door for direct reading and writing of the molecular spin-state by purely electrical means. In view of the intended investigations of the magnetic properties of the NdPc$_{2}$ molecule coupled to ferromagnetic surfaces, spin-polarized STM investigations of the second atomic layer of Fe on W(110) are performed. Here, bulk Cr-tips are used, which were ex-situ electrochemically etched from a Cr rod. Further in-situ treatment is shown to have no essential influence on the magnetic properties of the tips. The reproducible and reliable preparation of the ferromagnetic substrate and the Cr-tips is the basis for further investigations of the NdPc$_{2}$ molecule adsorbed on the second atomic layer of Fe on W(110). Preliminary STM and STS results give strong evidence, that the direct access to the spin-polarized 4$\textit{f}$-states is also feasible after adsorption of the double-decker molecule on a ferromagnetic substrate

The isogeometric collocated contact surface approach

We propose a frictionless contact formulation for isogeometric analysis, which combines a collocated formulation for the contact surfaces with a standard Galerkin treatment of the bulk. We denote it as isogeometric Collocated Contact Surface (CCS) formulation. The approach is based on a simple pointwise enforcement of the contact constraints, performed in this study with the penalty method. Unlike pointwise (node-to-surface or point-to-surface) contact algorithms in the Galerkin framework, the CCS formulation passes the contact patch test to machine precision by naturally exploiting the favorable properties of isogeometric collocation. Compared with approaches where the discretization of both bulk and contact surfaces is based on collocation, the CCS approach does not need enhancements to remove oscillations for highly non-uniform meshes. With respect to integral contact approaches, the CCS algorithm is less computationally expensive, due to the reduced amount of contact evaluation points. In addition, the CCS approach is easy to code and can be added to a pre-existing isogeometric analysis code with minimal effort. Numerical examples in both small and large deformations are investigated to compare the CCS approach with some available contact formulations and to demonstrate its accuracy.ISSN:0178-7675ISSN:1432-092