An
in situ study of the clustered speckle 3D structure using an optical tweezer setup is presented. Clustered speckles appear when a coherently illuminated diffuser is imaged through a pupil mask ...with several apertures, properly distributed over a closed path, which is placed before the objective lens of a standard optical trapping system. Thus, light volumes are reduced several times when compared with standard speckles, being even smaller than the focus volume of a Gaussian beam commonly used to trap. Moreover, clustered speckles have odd statistical properties which differentiated it from standard speckles. Then, geometrically ordered multiple trapping arrays, with statistical random distribution of intensities, can be created with this technique. This fact could enable different studies concerning optical binding or new developments in coherent matter wave transport where Optical Trapping has been proven with standard speckles. In this work, a qualitative analysis of clustered speckles in an optical tweezer setup relative to the number of apertures in the mask and their size is carried on. Besides, in the Rayleigh regime, a general quantitative method to characterize the trapping capability of an optical field is proposed. Then, it is applied to clustered speckles. As a result, a relation between aperture size and the maximum size of the particles that could be trapped is found. This fact opens the possibility of engineering the statistic of the trapped particles by properly selecting the pupil mask.
Background
Cerebral vein thrombosis is a rare cause of stroke with significant risk of death and long-term dependency. Anticoagulation has been associated with better long-term prognosis, and vitamin ...K antagonists are usually prescribed in this setting.
Aim
The aim of this study was to present a series of 15 cerebral vein thrombosis patients treated with dabigatran.
Methods
Retrospective study of clinical, imaging, and follow-up characterization of all patients admitted with cerebral vein thrombosis and treated with dabigatran in a tertiary neurology department between June 2011 and December 2013 was conducted. Complications and adverse effects were recorded. Modified Rankin Scale was used to assess clinical severity; excellent outcome was defined as modified Rankin Scale at six-months of 0 to 1. Recanalization was assessed with an angiographic method (computer tomography, magnetic resonance imaging, or digital subtraction angiography).
Results
Eighteen patients were admitted for cerebral vein thrombosis. Dabigatran was started in 11 patients, and warfarin was started in 7. Four patients on warfarin were switched to dabigatran because of adverse effects at 0·5, 1, 3·5, and 4 months. A total of 15 patients were treated with dabigatran with median follow-up time of 19 months. Excellent outcome was observed in 87% of patients and recanalization in 80%.
Conclusions
We report the largest series of cerebral vein thrombosis patients treated with dabigatran. Clinical outcome was excellent in most patients and not different from other studies. Dabigatran could possibly be considered an alternative to warfarin; nevertheless, further prospective assessment with randomized controlled studies is warranted.
The prevention of recurrent hepatitis B virus (HBV) infection after orthotopic liver transplantation (OLT) with hepatitis B immunoglobulin (HBIG) is expensive and requires indefinite parenteral ...administration. Lamivudine is a nucleoside analogue capable of inhibiting HBV replication. The aim of this study is to determine the efficacy of lamivudine in the prevention of recurrent HBV infection after a course of HBIG in patients who were hepatitis B surface antigen (HBsAg) positive and hepatitis Be antigen (HBeAg) negative before OLT. Patients at high risk for recurrent HBV infection (HBeAg positive and HBV DNA positive) were excluded. Thirty HBsAg-positive, HBeAg-negative patients underwent OLT from January 1993 to June 1997. All 30 patients were administered HBIG after OLT and, after 2 years, were given the option of continuing with HBIG or switching to lamivudine. Five patients were excluded: 3 patients were lost to follow-up and 2 patients died of technical complications. Three patients terminated HBIG therapy at 8, 24, and 29 months after OLT, and reinfection with HBV occurred in 1 patient. Six patients elected to continue HBIG therapy for life; 1 patient died of melanoma and the remaining 5 patients are HBsAg negative, with an average follow-up of 73 months. Sixteen patients were converted to lamivudine after a course of HBIG, and all 16 patients are HBsAg negative, with an average follow-up of 51 months after OLT. Five patients have been on lamivudine monotherapy for more than 24 months. These results suggest that lamivudine administered after a posttransplantation course of HBIG can effectively prevent the recurrence of HBV infection in patients who are HBsAg positive and HBeAg negative before OLT. (Liver Transpl 2000;6:434-439.)
In this paper, a PVC filled with a biodegradable polymer, such as polyhydroxybutyrate, was investigated. Polyhydroxybutyrate is a natural biopolymer, but its use limits its high cost. These polymeric ...composites were obtained by rolling. Thermal and thermomechanical properties of polymer composites based on PVC containing various amounts of polyhydroxybutyrate are studied. It has been determined by differential scanning calorimetry method that the glass transition temperature of PVC decreases with increasing percentage of polyhydroxybutyrate filling. For these composite materials, the TMA method yields flow curves, thermomechanical curves. It is determined that unfilled PVC shows a slight deformation and the smallest irreversible deformation. With an increase in the PHB content, both elastic deformation and a viscous flow increase in polymer composites, i.e. with increasing the proportion of polyhydroxybutyrate in the mixture, the elastic properties of the composite increase. Thus, in general, the addition of polyhydroxybutyrate does not significantly impair the performance properties of the resulting composite materials.
The purpose of this study was to identify risk factors that may predict heart failure with reduced ejection fraction (HFrEF) following orthotopic liver transplantation (OLT) and associated mortality.
...HFrEF following OLT is a poorly understood phenomenon, reported in 3% to 7% of transplanted patients.
This is a retrospective analysis of 176 consecutive patients who underwent OLT from 2010 to 2017. Multivariate logistic regression was used to identify associations between cardiovascular risk factors and perioperative variables with post-OLT HFrEF, defined as reduction in left ventricular ejection fraction of at least 10% and left ventricular ejection fraction less than or equal to 40% with acute heart failure symptoms. Multivariate cox proportional hazards regression (with inverse probability weighting by propensity scores) was used to evaluate effects of HFrEF on 1-year mortality.
Of the176 patients, 14% developed HFrEF with a median of 5 days. History of heart failure (OR 10.99, 2.15–56.09; P = .04) and intraoperative transfusion of greater than 11 units of packed red blood cells (OR 3.377, 1.025–11.13; P = .045) were associated with increased incidence of HFrEF. Pre-transplant hemoglobin greater than 8.5 g/dL (OR 0.252, CI 0.0954- 0.665; P = .05) was protective against HFrEF. Thirty-three percent of HFrEF group died within 1 year (HR 7.36, 2.57–21.12; P < .001).
The incidence of acute HFrEF post-OLT is 14% and is associated with a 7-fold increase in 1-year mortality. Cirrhotic cardiomyopathy and stress-induced cardiomyopathy maybe the underlying mechanisms. Our study identified risk factors associated with post-OLT HFrEF and should provide additional guidance for risk stratification of patients undergoing OLT.
Seismic refraction velocity-versus depth models can complement our understanding of natural soils beneath flood protection levees at locations between geotechnical sites. Levee failures in New ...Orleans in 2005 are attributable in part to poor understanding of sediments between geotechnical sites. To a first order, subsurface fluvial–deltaic facies in the lower Mississippi delta plain correlate with general geotechnical properties of water content and cohesive strength, but are too laterally variable to be easily predicted from geotechnical sites spaced 100m apart.
An artificial earthen levee, suitable for seismic investigation, lies ~15km S of the city of New Orleans, Louisiana. Values of shear-wave velocity (VSH) versus depth (0–20m) are derived by forward-ray-trace models of seismic refraction arrivals which match key boundaries identified at (geotechnical) cone-penetration testing sites, spaced at 300m apart. In particular, a 100-m section along the levee crest shows continuous cracks which are as much as 10cm wide, and 30cm deep at their northern end. Cracking may relate to high strain, induced by variable near-surface subsidence of organic-rich sediments. Topographic cross-sections across the levee show variable differential subsidence of 1–2m. Based on effective medium theory, VP- and VSH-versus-depth profiles indicate unexpectedly greater saturation and lower shear moduli on the unprotected levee side adjacent to the cracks.
Integration of geophysical, sedimentary and topographic data, even if only at a few locations can help locate anomalous zones in sub-levee soil between geotechnical boring sites. Future preventive monitoring of flood-protection barriers stands to benefit greatly from integrated data sets “ground truthed” to geotechnical data.
•Seismic monitoring of natural soils beneath man-made levees complements CPT data.•Large VP/VS ratios (8–9) indicate proximity to full saturation.•Differential compaction of organic-rich materials may distress levee.
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