6 research outputs found

    A covalently crosslinked bioink for multi-materials drop-on-demand 3D bioprinting of three-dimensional cell cultures

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    In vitro three-dimensional (3D) cell models have been accepted to better recapitulate aspects of in vivo organ environment than 2D cell culture. Currently, the production of these complex in vitro 3D cell models with multiple cell types and microenvironments remains challenging and prone to human error. Here we report a versatile bioink comprised of a 4-arm PEG based polymer with distal maleimide derivatives as the main ink component and a bis-thiol species as the activator that crosslinks the polymer to form the hydrogel in less than a second. The rapid gelation makes the polymer system compatible with 3D bioprinting. The ink is combined with a drop-on-demand 3D bioprinting platform consisting of eight independently addressable nozzles and high-throughput printing logic for creating complex 3D cell culture models. The combination of multiple nozzles and fast printing logic enables the rapid preparation of many complex 3D structures comprising multiple hydrogel environments in the one structure in a standard 96-well plate format. The platform compatibility for biological applications was validated using pancreatic ductal adenocarcinoma cancer (PDAC) cells with their phenotypic responses controlled by tuning the hydrogel microenvironment

    TRY plant trait database - enhanced coverage and open access

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    Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits—almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    Revelando o vírus, ocultando pessoas: exames de monitoramento (CD4 e CVP) e relação médico-paciente no contexto da AIDS Disclosing the virus, hiding the patients: follow-up tests (CD4 and VL) and the physician-patient relationship in the AIDS setting

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    O objetivo deste artigo é discutir os significados associados aos exames de contagem de linfócitos CD4 e quantificação da carga viral plasmática do HIV (CVP) para pacientes vivendo com AIDS e médicos da atenção, buscando analisar os reflexos de sua crescente utilização na relação terapêutica. Foi realizado um estudo qualitativo em dois centros de referência em HIV/AIDS com observação participante e entrevistas semi-estruturadas com 27 pacientes vivendo com AIDS e quatro médicos. A observação das consultas médicas mostrou que elas são rápidas, objetivas e centradas no resultado dos exames CD4 e CVP, o que reforça uma visão hegemônica do saber médico e uma perspectiva biomédica que instrumentaliza a sua prática. Para médicos e pacientes, os exames passam a refletir a "verdade" sobre a doença do paciente em detrimento da anamnese e do exame clínico, fato que se reflete na relação terapêutica e na desatenção por parte dos médicos à subjetividade dos pacientes. Mais do que nunca há necessidade da retomada da prática da boa clínica e do reconhecimento do papel do sujeito na prática da medicina como arte de curar.<br>The aim of this study is to discuss the meanings associated with the CD4 lymphocyte count and HIV plasma viral load (VL) for patients living with AIDS and the attending physicians, seeking to analyze the impacts of the increasing use of these tests in the treatment setting. A qualitative study was performed in two HIV/AIDS referral centers with participant observation and semi-structured interviews with 27 patients living with AIDS and four physicians. Observation of the medical consultations showed that they are quick, objective, and centered on the CD4 and VL test results, thus reinforcing a hegemonic view of medical knowledge and a biomedical perspective that instrumentalizes their practice. For physicians and patients, the tests tend to reflect the "truth" on the patient's disease, to the detriment of the patient history and clinical examination, impacting the therapeutic relationship and leading to the physician's lack of attention to the patients' subjectivity. More than ever, there is a need to reclaim good clinical practice and acknowledge the subject's role in medical practice as a healing art

    Delayed colorectal cancer care during covid-19 pandemic (decor-19). Global perspective from an international survey

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    Background The widespread nature of coronavirus disease 2019 (COVID-19) has been unprecedented. We sought to analyze its global impact with a survey on colorectal cancer (CRC) care during the pandemic. Methods The impact of COVID-19 on preoperative assessment, elective surgery, and postoperative management of CRC patients was explored by a 35-item survey, which was distributed worldwide to members of surgical societies with an interest in CRC care. Respondents were divided into two comparator groups: 1) ‘delay’ group: CRC care affected by the pandemic; 2) ‘no delay’ group: unaltered CRC practice. Results A total of 1,051 respondents from 84 countries completed the survey. No substantial differences in demographics were found between the ‘delay’ (745, 70.9%) and ‘no delay’ (306, 29.1%) groups. Suspension of multidisciplinary team meetings, staff members quarantined or relocated to COVID-19 units, units fully dedicated to COVID-19 care, personal protective equipment not readily available were factors significantly associated to delays in endoscopy, radiology, surgery, histopathology and prolonged chemoradiation therapy-to-surgery intervals. In the ‘delay’ group, 48.9% of respondents reported a change in the initial surgical plan and 26.3% reported a shift from elective to urgent operations. Recovery of CRC care was associated with the status of the outbreak. Practicing in COVID-free units, no change in operative slots and staff members not relocated to COVID-19 units were statistically associated with unaltered CRC care in the ‘no delay’ group, while the geographical distribution was not. Conclusions Global changes in diagnostic and therapeutic CRC practices were evident. Changes were associated with differences in health-care delivery systems, hospital’s preparedness, resources availability, and local COVID-19 prevalence rather than geographical factors. Strategic planning is required to optimize CRC care
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