ST2 and Multimarker Testing in Acute Decompensated Heart Failure

Most data on heart failure biomarkers have been derived from patient cohorts with chronic disease. However, risk prediction in patients admitted with acute decompensated heart failure (ADHF) remains a challenge. ADHF is not a single disease: it presents in various manners, and different causes may underlie ADHF, which may be reflected by different biomarkers. Soluble suppression of tumorigenicity 2 (ST2) has been shown to be a strong independent predictor of short-, mid-, and long-term outcome in ADHF. Furthermore, combining biomarkers may help further improve the prognostic power of ST2. The ProBNP Investigation of Dyspnea in the Emergency Department study showed that elevated plasma levels of ST2 together with elevated levels of 4 other biomarkers have clear incremental values to predict outcome in ADHF. The Multinational Observational Cohort on Acute Heart Failure study is an international collaborative network that recruited 5,306 patients hospitalized for ADHF that demonstrated that ST2 and midregional pro-adrenomedulin had independently strong value to predict 30-day and 1-year outcome in patients with ADHF. The Multinational Observational Cohort on Acute Heart Failure study also showed that C-reactive protein plus ST2 better classified risk in patients with ADHFs than ST2 alone. Combining biomarkers for risk prediction or risk stratification might have clinical and more importantly pathophysiological meaning

Effect of concentration on shear and extensional rheology of guar gum solutions

The steady shear and extensional rheology of aqueous guar gum solutions was studied for concentrations, C, ranging from 1 g/L to 20 g/L. Extensional rheometry measurements were made using the Cambridge Trimaster filament-stretching device. The steady shear tests indicated a transition between a semi-dilute regime, below 10 g/L, and an entangled regime at higher concentrations. The solutions were shear-thinning and obeyed the unmodified Cox–Merz rule in the dilute regime, but deviated from Cox–Merz and exhibited strongly viscoelastic behaviour at higher concentrations. The surface tension at higher concentration also deviated from the Szyszkowski model, exhibiting behaviour consistent with entanglement. The filament-thinning data did not fit the model for polymer solution behaviour presented by Entov and Hinch (1997), but gave a good fit to a modified form where time was normalised by the time for filament break-up. This scaling was independent of concentration effects, as reported by Chesterton, Meza, Moggridge, Sadd, and Wilson (2011) for cake batters. The modified model parameters approached asymptotic values for entangled solutions. The estimated apparent extensional viscosity exhibited a peak at unit strain followed by a constant value. The former increased as Cn, where n > 1, while the latter increased linearly with C.The authors acknowledge the financial support (POS-A/2012/116) from Xunta de Galicia’s Consellería de Cultura, Educación e Ordenación Universitaria of Spain and European Union’s European Social Fund.This is the accepted manuscript version. The final published version of the article is available from Elsevier at http://www.sciencedirect.com/science/article/pii/S0268005X14000605

Generating arbitrary ultrasound fields with tailored optoacoustic surface profiles

Acoustic fields with multiple foci have many applications in physical acoustics ranging from particle manipulation to neural modulation. However, the generation of multiple foci at arbitrary locations in three-dimensional is challenging using conventional transducer technology. In this work, the optical generation of acoustic fields focused at multiple points using a single optical pulse is demonstrated. This is achieved using optically absorbing surface profiles designed to generate specific, user-defined, wavefields. An optimisation approach for the design of these tailored surface profiles is developed. This searches for a smoothly varying surface that will generate a high peak pressure at a set of target focal points. The designed surface profiles are then realised via a combination of additive manufacturing and absorber deposition techniques. Acoustic field measurements from a sample designed to generate the numeral “7” are used to demonstrate the design method

Underwater Multi-Robot Convoying using Visual Tracking by Detection

We present a robust multi-robot convoying approach that relies on visual detection of the leading agent, thus enabling target following in unstructured 3-D environments. Our method is based on the idea of tracking-by-detection, which interleaves efficient model-based object detection with temporal filtering of image-based bounding box estimation. This approach has the important advantage of mitigating tracking drift (i.e. drifting away from the target object), which is a common symptom of model-free trackers and is detrimental to sustained convoying in practice. To illustrate our solution, we collected extensive footage of an underwater robot in ocean settings, and hand-annotated its location in each frame. Based on this dataset, we present an empirical comparison of multiple tracker variants, including the use of several convolutional neural networks, both with and without recurrent connections, as well as frequency-based model-free trackers. We also demonstrate the practicality of this tracking-by-detection strategy in real-world scenarios by successfully controlling a legged underwater robot in five degrees of freedom to follow another robot's independent motion.Comment: Accepted to IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 201

Effect of bubble volume fraction on the shear and extensional rheology of bubbly liquids based on guar gum (a Giesekus fluid) as continuous phase

The effect of air bubble volume fraction, ϕ, on the steady shear and extensional rheology of aqueous guar gum solutions was studied at 0 ≤ ϕ ≤ 0.25 and gum concentrations of (i) 5° g/L and (ii) 10 g/L, corresponding to solutions in the (i) semi-dilute and (ii) entanglement regime. The rheological response of the fluids was largely independent of bubble size but strongly dependent on ϕ. The viscous and elastic moduli increased with increasing bubble volume fraction, with elastic dominance prevalent at the higher gum concentration. Extensional rheometry, investigated using filament stretching, revealed that the thinning dynamics of the liquid thread were affected by bubble size, but the filament rupture time was primarily dependent on ϕ. The rheological behaviour in both shear and extension could be modelled as a single mode Giesekus fluid, with a single set of parameters able to describe both the shear and extensional behaviour in the semi-dilute regime. In the entanglement regime the single mode Giesekus fluid could fit the shear data or the extensional data individually, but not both. The fitted Giesekus fluid model parameters exhibited a strong dependency on ϕ, offering a way to predict the flow behaviour of these complex food fluids.This is the author's accepted manuscript. The final version is available from Elsevier in the Journal of Food Engineering (http://www.sciencedirect.com/science/article/pii/S0260877414003744)

Evaluating the Surgeons' Perception of Difficulties of Two Techniques to Perform STARR for Obstructed Defecation Syndrome: A Multicenter Randomized Trial.

BACKGROUND After initial enthusiasm in the use of a dedicated curved stapler (CCS-30 Contour Transtar) to perform stapled transanal rectal resection (STARR) for obstructed defecation syndrome (ODS), difficulties have emerged in this surgical technique. OBJECTIVE First, to compare surgeons' perception of difficulties of STARR performed with only Transtar versus STARR performed with the combined use of linear staplers and Transtar to cure ODS associated with large internal prolapse and rectocele; second, to compare the postoperative incidence of the urge to defecate between the 2 STARR procedures. DESIGN AND SETTING An Italian multicenter randomized trial involving 25 centers of colorectal surgery. PATIENTS Patients with obstructed defecation syndrome and rectocele or rectal intussusception, treated between January and December 2012. INTERVENTIONS Participants were randomly assigned to undergo STARR with a curved alone stapler (CAS group) or with the combined use of linear and curved staplers (LCS group). MAIN OUTCOME MEASURES Primary end-points were the evaluation of surgeons' perception of difficulties score and the incidence of the "urge to defecate" at 3-month follow up. Secondary end-points included duration of hospital stay, rates of early and late complications, incidence of "urge to defecate" at 6 and 12 months, success of the procedures at 12 months of follow-up. RESULTS Of 771 patients evaluated, 270 patients (35%) satisfied the criteria. Follow-up data were available for 254 patients: 128 patients (114 women) in the CAS group (mean age, 52.1; range, 39-70 years) and 126 (116 women) in LCS group (mean age, 50.7 years; range, 41-75 years). The mean surgeons' perception score, was 15.36 (SD, 3.93) in the CAS group and 12.26 (SD, 4.22) in the LCS group (P < .0001; 2-sample t test). At 3-month follow-up, urge to defecate was observed in 18 (14.6%) CAS group patients and in 13 (10.7%) LCS group patients (P = .34; Fisher's exact test). These values drastically decrease at 6 months until no urge to defecate in all patients at 12 months was observed. At 12-month follow-up, a successful outcome was achieved in 100 (78.1%) CAS group patients and in 105 (83.3%) LCS group patients (P = .34; Fisher's exact test). No significant differences between groups were observed in the hospital stay and rates of early or late complications occurring after STARR. CONCLUSIONS STARR with Transtar associated with prior decomposition of prolapse, using linear staplers, seems to be less difficult than that without decomposition. Both procedures appear to be safe and effective in the treatment of obstructed defecation syndrome resulting in similar success rates and complications

An improved method on stimulated T-lymphocytes to functionally characterize novel and known LDLR mutations.

The main causes of familial hypercholesterolemia (FH) are mutations in LDL receptor (LDLR) gene. Functional studies are necessary to demonstrate the LDLR function impairment caused by mutations and would be useful as a diagnostic tool if they allow discrimination between FH patients and controls. In order to identify the best method to detect LDLR activity, we compared continuous Epstein-Barr virus (EBV)-transformed B-lymphocytes and mitogen stimulated T-lymphocytes. In addition, we characterized both novel and known mutations in the LDLR gene. T-lymphocytes and EBV-transformed B-lymphocytes were obtained from peripheral blood of 24 FH patients and 24 control subjects. Functional assays were performed by incubation with fluorescent LDL followed by flow cytometry analysis. Residual LDLR activity was calculated normalizing fluorescence for the mean fluorescence of controls. With stimulated T-lymphocytes we obtained a better discrimination capacity between controls and FH patients compared with EBV-transformed B-lymphocytes as demonstrated by receiver operating characteristic (ROC) curve analysis (the areas under the curve are 1.000 and 0.984 respectively; P < 0.0001 both). The characterization of LDLR activity through T-lymphocytes is more simple and faster than the use of EBV-transformed B-lymphocytes and allows a complete discrimination between controls and FH patients. Therefore the evaluation of residual LDLR activity could be helpful not only for mutation characterization but also for diagnostic purposes

A Study into the Effect of the Presence of Moisture at the Wheel/Rail Interface during Dew and Damp Conditions

Incidents involving low levels of adhesion between the wheel and rail are a recurrent issue in the rail industry. The problem has been mitigated using friction modifiers and traction enhancers, but a significant number of incidents still occur throughout the year. The following work looks at the environmental conditions that surround periods of low adhesion in order to provide an insight into why low adhesion events occur. Network Rail Autumn data, which provided details on the time and location of low adhesion incidents, was compared against weather data on a national and then local scale. Low adhesion incidents have often been attributed to contamination on the rail, such as organic leaf matter, but other incidents occur when no contamination is visible. The time, date and location of incidents were linked to local weather data to establish any specific weather conditions that could lead to these events. The effects of precipitation, temperature and humidity on the rail were analysed in order to further the understanding of low adhesion in the wheel-rail contact, which will lead to better methods of mitigating this problem