294 research outputs found
Influence of socioeconomic factors on pregnancy outcome in women with structural heart disease
OBJECTIVE: Cardiac disease is the leading cause of indirect maternal mortality. The aim of this study was to analyse to what extent socioeconomic factors influence the outcome of pregnancy in women with heart disease. METHODS: The Registry of Pregnancy and Cardiac disease is a global prospective registry. For this analysis, countries that enrolled ≥10 patients were included. A combined cardiac endpoint included maternal cardiac death, arrhythmia requiring treatment, heart failure, thromboembolic event, aortic dissection, endocarditis, acute coronary syndrome, hospitalisation for cardiac reason or intervention. Associations between patient characteristics, country characteristics (income inequality expressed as Gini coefficient, health expenditure, schooling, gross domestic product, birth rate and hospital beds) and cardiac endpoints were checked in a three-level model (patient-centre-country). RESULTS: A total of 30 countries enrolled 2924 patients from 89 centres. At least one endpoint occurred in 645 women (22.1%). Maternal age, New York Heart Association classification and modified WHO risk classification were associated with the combined endpoint and explained 37% of variance in outcome. Gini coefficient and country-specific birth rate explained an additional 4%. There were large differences between the individual countries, but the need for multilevel modelling to account for these differences disappeared after adjustment for patient characteristics, Gini and country-specific birth rate. CONCLUSION: While there are definite interregional differences in pregnancy outcome in women with cardiac disease, these differences seem to be mainly driven by individual patient characteristics. Adjustment for country characteristics refined the results to a limited extent, but maternal condition seems to be the main determinant of outcome
ViTally Consistent:Scaling Biological Representation Learning for Cell Microscopy
Large-scale cell microscopy screens are used in drug discovery and molecular biology research to study the effects of millions of chemical and genetic perturbations on cells. To use these images in downstream analysis, we need models that can map each image into a feature space that represents diverse biological phenotypes consistently, in the sense that perturbations with similar biological effects have similar representations. In this work, we present the largest foundation model for cell microscopy data to date, a new 1.9 billion-parameter ViT-G/8 MAE trained on over 8 billion microscopy image crops. Compared to a previous published ViT-L/8 MAE, our new model achieves a 60% improvement in linear separability of genetic perturbations and obtains the best overall performance on whole-genome biological relationship recall and replicate consistency benchmarks. Beyond scaling, we developed two key methods that improve performance: (1) training on a curated and diverse dataset; and, (2) using biologically motivated linear probing tasks to search across each transformer block for the best candidate representation of whole-genome screens. We find that many self-supervised vision transformers, pretrained on either natural or microscopy images, yield significantly more biologically meaningful representations of microscopy images in their intermediate blocks than in their typically used final blocks. More broadly, our approach and results provide insights toward a general strategy for successfully building foundation models for large-scale biological data
Polarizabilities of Adsorbed and Assembled Molecules: Measuring the Conductance through Buried Contacts
We have measured the polarizabilities of four families of molecules adsorbed to Au{111} surfaces, with structures ranging from fully saturated to fully conjugated, including single-molecule switches. Measured polarizabilities increase with increasing length and conjugation in the adsorbed molecules and are consistent with theoretical calculations. For single-molecule switches, the polarizability reflects the difference in substrate-molecule electronic coupling in the ON and OFF conductance states. Calculations suggest that the switch between the two conductance states is correlated with an oxidation state change in a nitro functional group in the switch molecules
Thermoelectric effect in molecular electronics
We provide a theoretical estimate of the thermoelectric current and voltage
over a Phenyldithiol molecule. We also show that the thermoelectric voltage is
(1) easy to analyze, (2) insensitive to the detailed coupling to the contacts,
(3) large enough to be measured and (4) give valuable information, which is not
readily accessible through other experiments, on the location of the Fermi
energy relative to the molecular levels. The location of the Fermi-energy is
poorly understood and controversial even though it is a central factor in
determining the nature of conduction (n- or p-type). We also note that the
thermoelectric voltage measured over Guanine molecules with an STM by Poler et
al., indicate conduction through the HOMO level, i.e., p-type conduction.Comment: 4 pages, 3 figure
Compound double ileoileal and ileocecocolic intussusception caused by lipoma of the ileum in an adult patient: A case report
<p>Abstract</p> <p>Introduction</p> <p>The initial diagnosis of intussusception in adults very often can be missed and cause delayed treatment and possible serious complications. We report the case of an adult patient with complicated double ileoileal and ileocecocolic intussusception.</p> <p>Case presentation</p> <p>A 46-year-old Caucasian man was transferred from the gastroenterology service to the abdominal surgery service with severe abdominal pain, nausea, and vomiting. An abdominal ultrasound, barium enema, and abdominal computed tomography scan revealed an intraluminal obstruction of his ascending colon. Plain abdominal X-rays showed diffuse air-fluid levels in his small intestine. A double ileoileal and ileocecocolic intussusception was found during an emergent laparotomy. A right hemicolectomy, including resection of a long segment of his ileum, was performed. The postoperative period was complicated by acute renal failure, shock liver, and pulmonary thromboembolism. Our patient was discharged from the hospital after 30 days. An anatomical pathology examination revealed a lipoma of his ileum.</p> <p>Conclusions</p> <p>Intussusception in adults requires early surgical resection regardless of the nature of the initial cause. Delayed treatment can cause very serious complications.</p
Robophony:A new voice in the soundscape
Soundscape studies typically distinguish between three sources of sound: biophony, sounds produced by animals, plants, and other biological entities; geophony, sounds produced by non-living features such as water or wind; and anthrophony, sounds produced by humans and human technology. Recent developments in the study of hybrid ecosystems and ecological robotics challenge these categorizations. A series of four soundscape interventions are considered, which lead to the proposal of a new category: robophony. These interventions — robots and autonomous digital agents — operate in feedback loops with the existing bio-, geo-, and anthrophony in the ecosystem. The properties that emerge from these cases: site specificity, hybrid sourcing, and layered temporality form the basis of this new category of sound in the soundscape
Content validity of the Recap of atopic eczema (RECAP) instrument in Dutch, English and German to measure eczema control in young people with atopic eczema: a cognitive interview study
Background: Recap of atopic eczema (RECAP) is a patient-reported outcome measure assessing eczema control. This instrument has been developed and validated in the UK. There are self-reported and proxy-reported versions in English, Dutch and German. However, it is unclear whether the self-reported version shows adequate content validity when completed by young people (8–16 years) in these languages. Objectives: To assess the content validity (comprehensibility, relevance and comprehensiveness) of the English, German and Dutch versions of the self-reported RECAP in young people with atopic eczema and to identify the most appropriate age cutoff for self-completion. Methods: We conducted 23 semistructured cognitive interviews with young people aged 8–16 years, using the ‘think-aloud’ method. In Germany and the Netherlands, participants were recruited in dermatology clinics and in the UK through social media and existing mailing lists. Interviews were audio recorded, transcribed verbatim and analysed in the three languages, using a problem-focused coding manual. Transcripts were coded by two independent reviewers in each country. Themes were translated into English and compared across the three countries. Results: Significant age-related comprehensibility issues with the last three items of the questionnaire occurred with young people aged 8–11 years, causing difficulties completing RECAP without help. However, older children had only minor problems and were able to complete the questionnaire by themselves. The self-reported version of RECAP has sufficient content validity for self-completion in young people aged 12 years and above. However, the German version with some translational adaptations may be appropriate for children from the age of 8 years. There may be some situations where the proxy version is needed for older children too. Conclusions: The self-reported version of RECAP is appropriate for use from the age of 12 years. The proxy version can be used in children younger than 12 years. Other measurement properties should be further investigated. What is already known about this topic? Recap of atopic eczema (RECAP) is an instrument recommended by the Harmonising Outcome Measures for Eczema initiative for the core outcome domain of long-term control of atopic eczema. Content validity of RECAP for self-completion by adults and of the proxy version has been assessed. What does this study add? In this study, content validity (comprehensibility, relevance and comprehensiveness) of the self-reported version of RECAP among young people (aged 8–16 years) with atopic eczema across the UK, Germany and the Netherlands is assessed. Based on these findings, key recommendations on how to measure eczema control in young people with atopic eczema are formulated. What are the clinical implications of this work? The Dutch, English and German self-completion versions of RECAP are recommended for use in adolescents from the age of 12 years. The proxy version could be used in children younger than 12 years or where children are cognitively or physically incapable of reporting their experience of eczema control. Caregivers should be encouraged to complete RECAP together with their child where possible
Vibration induced memory effects and switching in ac-driven molecular nanojunctions
We investigate bistability and memory effects in a molecular junction weakly
coupled to metallic leads with the latter being subject to an adiabatic
periodic change of the bias voltage. The system is described by a simple
Anderson-Holstein model and its dynamics is calculated via a master equation
approach. The controlled electrical switching between the many-body states of
the system is achieved due to polaron shift and Franck-Condon blockade in the
presence of strong electron-vibron interaction. Particular emphasis is given to
the role played by the excited vibronic states in the bistability and
hysteretic switching dynamics as a function of the voltage sweeping rates. In
general, both the occupation probabilities of the vibronic states and the
associated vibron energy show hysteretic behaviour for driving frequencies in a
range set by the minimum and maximum lifetimes of the system. The consequences
on the transport properties for various driving frequencies and in the limit of
DC-bias are also investigated.Comment: 15 pages, 20 figures, published versio
Oligo(aryleneethynylene)s with Terminal Pyridyl Groups: Synthesis and Length Dependence of the Tunneling-to-Hopping Transition of Single-Molecule Conductances
Electrons, Photons, and Force: Quantitative Single-Molecule Measurements from Physics to Biology
Single-molecule measurement techniques have illuminated unprecedented details of chemical behavior, including observations of the motion of a single molecule on a surface, and even the vibration of a single bond within a molecule. Such measurements are critical to our understanding of entities ranging from single atoms to the most complex protein assemblies. We provide an overview of the strikingly diverse classes of measurements that can be used to quantify single-molecule properties, including those of single macromolecules and single molecular assemblies, and discuss the quantitative insights they provide. Examples are drawn from across the single-molecule literature, ranging from ultrahigh vacuum scanning tunneling microscopy studies of adsorbate diffusion on surfaces to fluorescence studies of protein conformational changes in solution
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