Nanometric depth resolution from multi-focal images in microscopy

We describe a method for tracking the position of small features in three dimensions from images recorded on a standard microscope with an inexpensive attachment between the microscope and the camera. The depth-measurement accuracy of this method is tested experimentally on a wide-field, inverted microscope and is shown to give approximately 8 nm depth resolution, over a specimen depth of approximately 6 µm, when using a 12-bit charge-coupled device (CCD) camera and very bright but unresolved particles. To assess low-flux limitations a theoretical model is used to derive an analytical expression for the minimum variance bound. The approximations used in the analytical treatment are tested using numerical simulations. It is concluded that approximately 14 nm depth resolution is achievable with flux levels available when tracking fluorescent sources in three dimensions in live-cell biology and that the method is suitable for three-dimensional photo-activated localization microscopy resolution. Sub-nanometre resolution could be achieved with photon-counting techniques at high flux levels

Transesophageal echocardiography in orthotopic liver transplantation: a comprehensive intraoperative monitoring tool

Intraoperative transesophageal echocardiography is a minimally invasive monitoring tool that can provide real-time visual information on ventricular function and hemodynamic volume status in patients undergoing liver transplantation. The American Association for the Study of Liver Diseases states that transesophageal echocardiography should be used in all liver transplant candidates in order to assess chamber sizes, hypertrophy, systolic and diastolic function, valvular function, and left ventricle outflow tract obstruction. However, intraoperative transesophageal echocardiography can be used to â\u80\u9cvisualizeâ\u80\u9d other organs too; thanks to its proximity and access to multiple acoustic windows: liver, lung, spleen, and kidney. Although only limited scientific evidence exists promoting this comprehensive use, we describe the feasibility of TEE in the setting of liver transplantation: it is a highly valuable tool, not only as a cardiovascular monitoring, but also as a tool to evaluate lungs and pleural spaces, to assess hepatic vein blood flow and inferior vena cava anastomosis and patency, i.e., in cases of modified surgical techniques. The aim of this case series is to add our own experience of TEE as a comprehensive intraoperative monitoring tool in the field of orthotopic liver transplantation (and major liver resection) to the literature

Screening Tests for Assessing Athletes at Risk of ACL Injury or Reinjury-A Scoping Review

Various tests are available to assess athletes for factors associated with their susceptibility and risk of anterior cruciate ligament (ACL) injury or reinjury; however, it is unclear which tests are clinically meaningful and what should be considered when using them. Therefore, the aim of this scoping review was to screen and summarize testing and to derive evidence-based recommendations for clinicians, practitioners and future research. Five databases were searched to identify studies addressing musculoskeletal morphology or functional-performance-related screening tests with a clear conceptual link or an evidence-based relationship to ACL (re)injury. A quality rating was carried out using the National Institutes of Health (NIH) Study-Quality Assessment Tool. Six different categories of common screening tests were identified: balance and postural control, gait- and running-related tests, joint laxity, joint morphology and anthropometrics, jump tests and strength tests. Predicting future injury in a complex, dynamic system based on a single screening test is methodologically challenging, which is also reflected in the highly controversial findings in the literature regarding potential associations between specific screening tests and the occurrence of ACL injuries and reinjuries. Nonetheless, various screening tests can provide clinically relevant information on ACL-(re)injury-related factors and help to provide tailored preventive measures. A selection of corresponding evidence-based recommendations is derived and presented in this scoping review

Variable optical elements for fast focus control

In this Review, we survey recent developments in the emerging field of high-speed variable-z-focus optical elements, which are driving important innovations in advanced imaging and materials processing applications. Three-dimensional biomedical imaging, high-throughput industrial inspection, advanced spectroscopies, and other optical characterization and materials modification methods have made great strides forward in recent years due to precise and rapid axial control of light. Three state-of-the-art key optical technologies that enable fast z-focus modulation are reviewed, along with a discussion of the implications of the new developments in variable optical elements and their impact on technologically relevant applications

A clinical reasoning framework for thoracic spine exercise prescription in sport:a systematic review and narrative synthesis

BackgroundThe thoracic spine is critical for athletic kinetic chain functioning yet widely overlooked in terms of specific evidenced-based exercise prescription. Thoracic mobility, motor control and strength are required to optimise performance in sport and minimise excessive load/stress on other components of the kinetic chain.ObjectiveTo identify and evaluate mobility, motor control, work capacity and strength thoracic exercises for use in athletes.DesignSystematic review involving expert reviewers at key stages: searches and screening (n=1), eligibility, evaluation, data extraction and evaluation (n=3). Key databases and social media sources were searched to 16 August 2019. Eligible exercises were thoracic exercises to promote mobility, motor control, work capacity and strength. A narrative synthesis enabled an outcome-based classification of exercises, with level of evidence of individual sources informing overall level of evidence for each outcome (Oxford Centre for Evidence-based Medicine).ResultsFrom 2348 sources (social media, database searches and other sources), 38 exercises were included. Sources included images, video clips and written descriptions of exercises. Exercises targeting all planes of motion were evaluated and classified according to outcome. Exercises comprised functional and non-functional exercises for mobility (n=9), work capacity (n=15), motor control (n=7) and strength (n=7). Overall level of evidence for each outcome was level 5.ConclusionThis synthesis and evaluation of exercises has captured the scope of thoracic exercises used in ‘practice’. Evaluation against an expert-derived outcome-based classification provides practitioners with a framework to facilitate exercise prescription. Evaluation of validity and effectiveness of exercises on outcomes is now required