A stereoscopic ranging system using standard PC technology

A stereoscopic ranging system is currently being developed as a key source of positional information for an underwater ROV station keeping system. Advancements in PC technology make it possible to use a relatively simple image capture card and a PC as a platform for the fast capture and processing of video images. We make use of the extensive capabilities of fast data buses and the high processing power of fast PCs with Pentium II or III processors. Using this approach we are developing an image processing system that is largely manufacturer independent and promises a good path for both hardware and software upgrading in the future

Transition from single-file to two-dimensional diffusion of interacting particles in a quasi-one-dimensional channel

Diffusive properties of a monodisperse system of interacting particles confined to a \textit{quasi}-one-dimensional (Q1D) channel are studied using molecular dynamics (MD) simulations. We calculate numerically the mean-squared displacement (MSD) and investigate the influence of the width of the channel (or the strength of the confinement potential) on diffusion in finite-size channels of different shapes (i.e., straight and circular). The transition from single-file diffusion (SFD) to the two-dimensional diffusion regime is investigated. This transition (regarding the calculation of the scaling exponent ($\alpha$) of the MSD $$ $\propto t^{\alpha}$) as a function of the width of the channel, is shown to change depending on the channel's confinement profile. In particular the transition can be either smooth (i.e., for a parabolic confinement potential) or rather sharp/stepwise (i.e., for a hard-wall potential), as distinct from infinite channels where this transition is abrupt. This result can be explained by qualitatively different distributions of the particle density for the different confinement potentials.Comment: 13 pages, 11 figure

Using self-driven microswimmers for particle separation

Microscopic self-propelled swimmers capable of autonomous navigation through complex environments provide appealing opportunities for localization, pick-up and delivery of micro-and nanoscopic objects. Inspired by motile cells and bacteria, man-made microswimmers have been fabricated, and their motion in patterned surroundings has been experimentally studied. We propose to use self-driven artificial microswimmers for separation of binary mixtures of colloids. We revealed different regimes of separation including one with a velocity inversion. Our finding could be of use for various biological and medical applications.Comment: 6 pages, 5 figure

An RNA in situ hybridization protocol optimized for monocot tissue

RNA in situ hybridization can be time-consuming and difficult to troubleshoot. Here, we provide an optimized protocol for maize leaf tissue, though it can be applied to other plant tissues such as shoot apical meristems, embryos, and floral organs. We generate three >100 bp unique antisense probes for each gene of interest and hybridize them to tissue sections

The Exeter femoral stem continues to migrate during its first decade after implantation: 10–12 years of follow-up with radiostereometric analysis (RSA)

Optimising joint reconstruction management in arthritis and bone tumour patient

Preventing VTE following total hip and knee arthroplasty: is prediction the future?

Venous thromboembolism (VTE) is a common complication following total hip arthroplasty (THA) and total knee arthroplasty (TKA). Many guidelines advise on the ideal pharmacological thromboprophylaxis strategy; however, despite its use, approximately 1.5% of patients still develop symptomatic VTE. Considering the large number of THAs and TKAs performed worldwide (2.5 million in total), the impact of VTE following these interventions is enormous. This paper discusses a concept how to further lower rates of VTE and bleeding complications following surgery. By stratifying patients according to their risk, we can optimize the balance between VTE and bleeding for each individual. This way, low-risk patients may be safely withheld from treatment (and avoid unnecessary bleeding complications and costs), whereas high-risk patients should receive adequate therapy (for instance, an increased thromboprophylaxis dosage and duration). An individualized strategy requires a well-functioning VTE prediction model following THA and TKA to help physicians to decide on optimal thromboprophylaxis therapy.Thrombosis and Hemostasi

Similar risk of complete revision for infection with single-dose versus multiple-dose antibiotic prophylaxis in primary arthroplasty of the hip and knee:results of an observational cohort study in the Dutch Arthroplasty Register in 242,179 patients

Background and purpose - The optimal type and duration of antibiotic prophylaxis for primary arthroplasty of the hip and knee are subject to debate. We compared the risk of complete revision (obtained by a 1- or 2-stage procedure) for periprosthetic joint infection (PJI) after primary total hip or knee arthroplasty between patients receiving a single dose of prophylactic antibiotics and patients receiving multiple doses of antibiotics for prevention of PJI. Patients and methods - A cohort of 130,712 primary total hip and 111,467 knee arthroplasties performed between 2011 and 2015 in the Netherlands was analyzed. We linked data from the Dutch arthroplasty register to a survey collected across all Dutch institutions on hospital-level antibiotic prophylaxis policy. We used restricted cubic spline Poisson models adjusted for hospital clustering to compare the risk of revision for infection according to type and duration of antibiotic prophylaxis received. Results - For total hip arthroplasties, the rates of revision for infection were 31/10,000 person-years (95% CI 28-35), 39 (25-59), and 23 (15-34) in the groups that received multiple doses of cefazolin, multiple doses of cefuroxime, and a single dose of cefazolin, respectively. The rates for knee arthroplasties were 27/10,000 person-years (95% CI 24-31), 40 (24-62), and 24 (16-36). Similar risk of complete revision for infection among antibiotic prophylaxis regimens was found when adjusting for confounders. Interpretation - In a large observational cohort we found no apparent association between the type or duration of antibiotic prophylaxis and the risk of complete revision for infection. This does question whether there is any advantage to the use of prolonged antibiotic prophylaxis beyond a single dose.Orthopaedics, Trauma Surgery and Rehabilitatio

Complications and outcome of cats with congenital extrahepatic portosystemic shunts treated with thin film: Thirty-four cases (2008-2017)

Background: Congenital extrahepatic portosystemic shunts (CEHPSS) are rare in cats. Outcome after attenuation of CEHPSS with thin film has been described in a small number of cases. Objectives: To describe the clinical presentation, postoperative complications, and outcome of cats treated with thin film to attenuate CEHPSS. Animals: Thirty‐four cats with CEHPSS were identified from the database of 3 institutions over 9 years. Methods: Retrospective study. Medical records were reviewed to identify cats with a diagnosis of a CEHPSS that underwent surgical attenuation. Congenital extrahepatic portosystemic shunts were suspected from clinical signs, clinicopathologic findings, and diagnostic imaging, and confirmed at exploratory laparotomy. Cats treated with thin film band attenuation were included. Postoperative complications and follow‐up were recorded. Results: Complications were recorded in 11 of 34 cats. Deaths related to CEHPSS occurred in 6 of 34; 4 cats did not survive to discharge. Persistent seizures were the cause of death in 4 cats. Seizures were recorded in 8 of 34 cats after surgery; all these cats received preoperative antiepileptic drugs. Serum bile acid concentrations normalized in 25 of 28 of the cats for which data was available. Three cats had persistently increased serum bile acid concentrations and underwent a second exploratory laparotomy. One had a patent shunt, the other 2 had multiple acquired portosystemic shunts. Median follow‐up was 8 months (0.5‐84 months). Conclusions and Clinical Importance: Congenital extrahepatic portosystemic shunts attenuation using thin film in cats carries a good short‐ and mid‐term prognosis if they survive the postoperative period. Seizures were the most common cause of death