Virtual psychiatric care fast-tracked: reflections inspired by the COVID-19 pandemic

Summary For many patients and healthcare providers, the move to virtual psychiatric care has been fast-tracked by the COVID-19 pandemic. In this article, we consider a patient perspective and a provider perspective on the transition to virtual psychiatric care and its strengths and limitations, as well as a call for much-needed future research.</jats:p

Stochastic Modelling Of Symmetric Positive Definite Material Tensors

Spatial symmetries and invariances play an important role in the behaviour of materials and should be respected in the description and modelling of material properties. The focus here is the class of physically symmetric and positive definite tensors, as they appear often in the description of materials, and one wants to be able to prescribe certain classes of spatial symmetries and invariances for each member of the whole ensemble, while at the same time demanding that the mean or expected value of the ensemble be subject to a possibly ‘higher’ spatial invariance class. We formulate a modelling framework which not only respects these two requirements—positive definiteness and invariance—but also allows a fine control over orientation on one hand, and strength / size on the other. As the set of positive definite tensors is not a linear space, but rather an open convex cone in the linear space of physically symmetric tensors, we consider it advantageous to widen the notion of mean to the so-called Fréchet mean on a metric space, which is based on distance measures or metrics between positive definite tensors other than the usual Euclidean one. It is shown how the random ensemble can be modelled and generated, independently in its scaling and orientational or directional aspects, with a Lie algebra representation via a memoryless transformation. The parameters which describe the elements in this Lie algebra are then to be considered as random fields on the domain of interest. As an example, a 2D and a 3D model of steady-state heat conduction in a human proximal femur, a bone with high material anisotropy, is modelled with a random thermal conductivity tensor, and the numerical results show the distinct impact of incorporating into the constitutive model different material uncertainties—scaling, orientation, and prescribed material symmetry—on the desired quantities of interest

Collocation Methods and Beyond in Non-linear Mechanics

Within the realm of isogeometric analysis, isogeometric collocation has been driven by the attempt to minimize the cost of quadrature associated with higher-order discretizations, with the goal of achieving higher-order accuracy at low computational cost. While the first applications of isogeometric collocation have mainly concerned linear problems, here the focus is on non-linear mechanics formulations including hyperelasticity, elastoplasticity, contact and geometrically non-linear structural elements. We also address the treatment of locking issues as well as the establishment of a bridge between Galerkin and collocation schemes leading to a new reduced quadrature technique for isogeometric analysis. In stochastic uncertainty computations, the evaluation of full-scale deterministic models is the main computational burden, which may be avoided with cheap to evaluate proxy-models. Their construction is a kind of regression, which, when reduced to the minimum number of samples, turns into collocation or interpolation. It is possible to go well beyond that minimum using ideas from probabilistic numerics and Bayesian updating, which is shown both for constructing proxy-models and for upscaling (coarsening) of highly nonlinear material laws. Another way to reduce costly full-scale model evaluations is to use multi-level hierarchies of models, leading to multi-level Monte Carlo methods. In this chapter, we present the main achievements obtained on the above topics within the DFG Priority Program 1748, Reliable Simulation Techniques in Solid Mechanics.</p

Impact of COVID-19 and other pandemics and epidemics on people with pre-existing mental disorders: a systematic review protocol and suggestions for clinical care

IntroductionThe current COVID-19 pandemic has resulted in high rates of infection and death, as well as widespread social disruption and a reduction in access to healthcare services and support. There is growing concern over how the pandemic, as well as measures put in place to curb the pandemic, will impact people with mental disorders. We aim to study the effect of pandemics and epidemics on mental health outcomes for people with premorbid mental disorders.Methods and analysisWith our predefined search strategy, we will search five databases for studies reporting on mental health outcomes in people with pre-existing mental disorders during pandemic and epidemic settings. Search dates are planned as follows: 5 May 2020 and 23 July 2020. The following databases will be searched: MEDLINE/PubMed, CINAHL, PsycINFO, MedRxiv and EMBASE. Data will be screened and extracted in duplicate by two independent reviewers. Studies involving non-clinical populations or patients diagnosed with a mental disorder during a pandemic/epidemic will be excluded. We will include data collected from all pandemics and epidemics throughout history, including the present COVID-19 pandemic. If possible, study findings will be combined in meta-analyses, and subgroup analyses will be performed. We hope that this review will shed light on the impact of pandemics and epidemics on those with pre-existing mental disorders. Knowledge generated may inform future intervention studies as well as healthcare policies. Given the potential implications of the current pandemic measures (ie, disruption of healthcare services) on mental health, we will also compile a list of existing mental health resources.Ethics and disseminationNo ethical approval is required for this protocol and proposed systematic review as we will only use data from previously published papers that have themselves received ethics clearance and used proper informed consent procedures.Systematic review registrationPROSPERO registration number: CRD42020179611.</jats:sec

Properties, Engineering and Applications of PolymericNanofibers: Current Research and Future Advances

The subject of nanomedicine has seen a surge in research activity over the past decade, with nanofibers being a particularly active field. Nanofibers are solid, dry fibers with nanometer diameters, made of various polymers, whereas electrospinning is a versatile, simple, elegant, reproducible, continuous and scalable technology for their preparation. Nanofibers are a unique class of materials in the biomedical field, since they provide a biomimetic environment on the nanometer scale, a three-dimensional architecture with the desired surface properties on the micrometer scale, combined with mechanical strength and physiological acceptability on the macro scale. In particular, their ability to imitate the fibrillar elements of a natural extracellular matrix in a very realistic way is crucial. In this paper we introduce the fundamental aspects of the electrospinning process and the properties of nanofibers, as well as highlighting the enormous potential of nanofibers as drug-delivery systems and tissue scaffolds

Molecular mechanisms of behavioral manifestations of neurotoxicity induced by platinum-based chemotherapeutics: a beneficial role for antioxidant supplementation

For decades, platinum-based chemotherapeutics have been widely used in clinical protocols for numerous malignancies. However, despite their undisputed therapeutic potential, there clinical usage is limited by serious adverse effects. Neurotoxicity is one of the most frequent side effects of platinum-based compounds, and is associated with oxidative damage and pro-apoptotic activity. Thus, antioxidant supplementation may play a potential role in the treatment of platinum-based drug-induced neurotoxicity. In support of this, encouraging results were achieved using a variety of antioxidant-rich compounds. Our results suggest that synthetic and natural products with high antioxidant content may attenuate cisplatin-induced neurotoxicity by preventing oxidative damage and apoptosis in the brain. The beneficial role of antioxidant supplementation is further supported by their observed ability to reverse cisplatin-induced behavioral deterioration.Publishe

Recurrent acquisition of cytosine methyltransferases into eukaryotic retrotransposons

Transposable elements are in a constant arms race with the silencing mechanisms of their host genomes. One silencing mechanism commonly used by many eukaryotes is dependent on cytosine methylation, a covalent modification of DNA deposited by C5 cytosine methyltransferases (DNMTs). Here, we report how two distantly related eukaryotic lineages, dinoflagellates and charophytes, have independently incorporated DNMTs into the coding regions of distinct retrotransposon classes. Concomitantly, we show that dinoflagellates of the genus Symbiodinium have evolved cytosine methylation patterns unlike any other eukaryote, with most of the genome methylated at CG dinucleotides. Finally, we demonstrate the ability of retrotransposon DNMTs to methylate CGs de novo, suggesting that retrotransposons could self-methylate retrotranscribed DNA. Together, this is an example of how retrotransposons incorporate host-derived genes involved in DNA methylation. In some cases, this event could have implications for the composition and regulation of the host epigenomic environment

The genome of the crustacean Parhyale hawaiensis, a model for animal development, regeneration, immunity and lignocellulose digestion

The amphipod crustacean Parhyale hawaiensis is a blossoming model system for studies of developmental mechanisms and more recently regeneration. We have sequenced the genome allowing annotation of all key signaling pathways, transcription factors, and non-coding RNAs that will enhance ongoing functional studies. Parhyale is a member of the Malacostraca clade, which includes crustacean food crop species. We analysed the immunity related genes of Parhyale as an important comparative system for these species, where immunity related aquaculture problems have increased as farming has intensified. We also find that Parhyale and other species within Multicrustacea contain the enzyme sets necessary to perform lignocellulose digestion ('wood eating'), suggesting this ability may predate the diversification of this lineage. Our data provide an essential resource for further development of Parhyale as an experimental model. The first malacostracan genome will underpin ongoing comparative work in food crop species and research investigating lignocellulose as an energy source