Imaging morphological details and pathological differences of red blood cells using tapping-mode AFM

The surface topography of red blood cells (RBCs) was investigated under nearphysiological conditions using atomic force microscopy (AFM). An immobilization protocol was established where RBCs are coupled via molecular bonds of the membrane glycoproteins to wheat germ agglutinin (WGA), which is covalently and flexibly tethered to the support. This results in a tight but noninvasive attachment of the cells. Using tappingmode AFM, which is known as gentle imaging mode and therefore most appropriate for soft biological samples like erythrocytes, it was possible to resolve membrane skeleton structures without major distortions or deformations of the cell surface. Significant differences in the morphology of RBCs from healthy humans and patients with systemic lupus erythematosus (SLE) were observed on topographical images. The surface of RBCs from SLE patients showed characteristic circularshaped holes with approx. 200 nm in diameter under physiological conditions, a possible morphological correlate to previously published changes in the SLE erythrocyte membrane

A decreasing glacier mass balance gradient from the edge of the Upper Tarim Basin to the Karakoram during 2000-2014

In contrast to the glacier mass losses observed at other locations around the world, some glaciers in the High Mountains of Asia appear to have gained mass in recent decades. However, changes in digital elevation models indicate that glaciers in Karakoram and Pamir have gained mass, while recent laser altimetry data indicate mass gain centred on West Kunlun. Here, we obtain results that are essentially consistent with those from altimetry, but with two-dimensional observations and higher resolution. We produced elevation models using radar interferometry applied to bistatic data gathered between 2011 and 2014 and compared them to a model produced from bistatic data collected in 2000. The glaciers in West Kunlun, Eastern Pamir and the northern part of Karakoram experienced a clear mass gain of 0.043 ± 0.078~0.363 ± 0.065 m w.e. yr−1. The Karakoram showed a near-stable mass balance in its western part (−0.020 ± 0.064 m w.e. yr−1), while the Eastern Karakoram showed mass loss (−0.101 ± 0.058 m w.e. yr−1). Significant positive glacier mass balances are noted along the edge of the Upper Tarim Basin and indicate a decreasing gradient from northeast to southwest

Missing the human connection: A rapid appraisal of healthcare workers' perceptions and experiences of providing palliative care during the COVID-19 pandemic.

BACKGROUND: During infectious epidemics, healthcare workers are required to deliver traditional care while facing new pressures. Time and resource restrictions, a focus on saving lives and new safety measures can lead to traditional aspects of care delivery being neglected. AIM: Identify barriers to delivering end-of-life care, describe attempts to deliver care during the COVID-19 pandemic, and understand the impact this had on staff. DESIGN: A rapid appraisal was conducted incorporating a rapid review of policies from the United Kingdom, semi-structured telephone interviews with healthcare workers, and a review of mass print media news stories and social media posts describing healthcare worker's experiences of delivering care during the pandemic. Data were coded and analysed using framework analysis. SETTING/PARTICIPANTS: From a larger ongoing study, 22 interviews which mentioned death or caring for patients at end-of-life, eight government and National Health Service policies affecting end-of-life care delivery, eight international news media stories and 3440 publicly available social media posts were identified. The social media analysis centred around 274 original tweets with the highest reach, engagement and relevance. Incorporating multiple workstreams provided a broad perspective of end-of-life care during the COVID-19 pandemic in the United Kingdom. RESULTS: Three themes were developed: (1) restrictions to traditional care, (2) striving for new forms of care and (3) establishing identity and resilience. CONCLUSIONS: The COVID-19 pandemic prohibited the delivery of traditional care as practical barriers restricted human connections. Staff prioritised communication and comfort orientated tasks to re-establish compassion at end-of-life and displayed resilience by adjusting their goals

A Systematic Review of Tools and Recommendations Advising on the Use of Qualitative Data to Inform Epidemic Response Efforts in Low- and Middle-Income Settings

This review aimed to identify and critically assess tools and recommendations (collectively referred to as resources) advising on the use of qualitative data to inform epidemic response in low and middle income countries (LMICs). In doing so, we seek to improve the quality of these resources and ultimately support better integration of qualitative data in epidemic response initiatives. Literature were identified through three academic research databases and one gray literature repository. The search was conducted in April 2020 and updated in February 2021. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis checklist was adhered to. Furthermore, quality assessment tools were used for both academic (the Mixed Methods Appraisal Tool) and gray literature (the AACODS checklist standing for authority, accuracy, coverage, objectivity, date, and significance). The searches yielded 4,152 articles, of which 65 met the inclusion criteria. Identified tools and recommendations rarely provided sufficient information on how they should be implemented, who their intended audiences were, how they might be adapted across contexts and whether they might be useful to researchers on a longer or shorter timeframe. A significant amount of work remains to further develop the resources available to guide the use of qualitative data within the context of epidemic outbreaks in LMICs. Key considerations and implications based on the review outcomes are discussed

Dynamic force microscopy for imaging of viruses under physiological conditions

Dynamic force microscopy (DFM) allows imaging of the structure and the assessment of the function of biological specimens in their physiological environment. In DFM, the cantilever is oscillated at a given frequency and touches the sample only at the end of its downward movement. Accordingly, the problem of lateral forces displacing or even destroying bio-molecules is virtually inexistent as the contact time and friction forces are reduced. Here, we describe the use of DFM in studies of human rhinovirus serotype 2 (HRV2) weakly adhering to mica surfaces. The capsid of HRV2 was reproducibly imaged without any displacement of the virus. Release of the genomic RNA from the virions was initiated by exposure to low pH buffer and snapshots of the extrusion process were obtained. In the following, the technical details of previous DFM investigations of HRV2 are summarized

Twenty-first century glacier slowdown driven by mass loss in High Mountain Asia

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Nonlinear Dynamic Models of Piezoelectric Nano-Stages

High resolution imaging in scanning probe microscopes is conducted by rastering a sharp probe over a sample surface. The rastering is done using piezoelectric elements, converting applied voltage into mechanical motion. For example, imaging of a rectangular field of view is done by applying triangular waveforms with different frequencies to X and Y piezoelectric stage, respectively. A disadvantage of piezoelectric stages is their non-linear response to applied voltage. In addition to that, they show creep, i.e. moving even though the applied voltage is constant. This results in distortions of the acquired image. Furthermore, it can result in not precisely imaging the requested area. A common solution is to add position sensors to the piezoelectric stages and measure actual movements. By using a feedback it would be almost guaranteed that the piezoelectric stage moves as requested. The disadvantage of this approach is that it reduces the bandwidth and increases the noise. The aim of this paper is to study advanced piezoelectric stage models to better control the actual stage movement in an open-loop scan.</jats:p