Ultrasound-Assisted Catheter-Directed Thrombolysis for the Management of Pulmonary Embolism: A Single Center Experience in a Community Hospital.

Current guidelines recommend anticoagulation alone for low-risk pulmonary embolism (PE) with the addition of systemic thrombolysis for high-risk PE. However, treatment recommendations for intermediate-risk PE are not well-defined. Due to bleeding risks associated with systemic thrombolysis, ultrasound-assisted catheter-directed thrombolysis (USAT) has evolved as a promising treatment modality. USAT is thought to decrease the rate of major bleeding by using localized delivery with lower thrombolytic dosages. Currently, there is little guidance on the implementation of USAT in the real-world clinical setting. This study was designed to evaluate our experience with USAT at this single community hospital with a newly initiated Pulmonary Embolism Response Team (PERT). All patients identified by the PERT with an acute PE diagnosed by a computed tomography (CT) scan from January 2021 to January 2023 were included. During the study period, there were 89 PERT activations with 40 patients (1 high-risk and 37 intermediate-risk PE) receiving USAT with alteplase administered at a fixed rate of 1 mg/h per catheter for 6 h. The primary efficacy outcome was the change in Pulmonary Embolism Severity Index (PESI) score within 48 h after USAT. The primary safety outcome was major bleeding within 72 h. The mean age was 57.4 ± 17.4 years and 50% (n = 20) were male, 17.5% (n = 7) had active malignancy, and 20% (n = 8) had a history of prior deep vein thrombosis (DVT) or PE. The mean PESI score decreased from baseline to 48 h post-USAT (84.7 vs 74.9; p = 0.025) and there were no major bleeding events. The overall hospital length of stay was 7.5 ± 9.8 days and ICU length of stay was 2.2 ± 2.8 days. This study outlined our experience at this single community hospital which resulted in an improvement in PESI scores and no major bleeding events observed.

Development of Thermoplastic Composite Reinforced Ultra-High-Performance Concrete Panels for Impact Resistance.

In order to improve flexural and impact performance, thin panels of steel fiber-reinforced ultra-high performance concrete (UHPC) were further reinforced with external layers of continuous fiber-reinforced thermoplastic (CFRTP) composites. CFRTP sheets were bonded to 305 × 305 × 12 mm UHPC panels using two different techniques. First, unidirectional E-glass fiber-reinforced tapes of polyethylene terephthalate glycol-modified (PETG) were arranged in layers and fused to the UHPC panels through thermoforming. Second, E-glass fiber woven fabrics were placed on the panel faces and bonded by vacuum infusion with a methyl methacrylate (MAA) polymer. Specimens were cut into four 150 mm square panels for quasi-static and low-velocity impact testing in which loads were applied at the panel centers. Under quasi-static loading, both types of thermoplastic composite reinforcements led to a 150-180% increase in both peak load capacity and toughness. Impact performance was measured in terms of both residual deformation and change in specimen compliance, and CFRTP additions were reduced both by 80% to 95%, indicating an increase in damage resistance. While both reinforcement fabrication techniques provided added performance, the thermoforming method was preferable due to its simplicity and fewer specialized tool requirements.

Electrospinning of Cellulose Nanocrystal-Filled Poly (Vinyl Alcohol) Solutions: Material Property Assessment.

Poly (vinyl alcohol) (PVA) and cellulose nanocrystals (CNC) random composite mats were prepared using the electrospinning method. PVA/CNC mats were reinforced with weight concentrations of 0, 20 and 50% CNC (w/w) relative to PVA. Scanning electron microscopy was used to measure the fiber diameter, which ranged from 377 to 416 nm. Thermogravimetric analysis (TGA) confirmed the presence of CNC fibers in the mat fibers which were not visible by scanning electron microscope (SEM). Mechanical testing was conducted using ASTM D 638 on each sample group at 10 mm min-1. Neat PVA and PVA/CNC mats were heat treated at 170 °C for 2h hours, and the morphological structure was maintained with some fiber diameter reduction. Mechanical property results after heat treatment showed a decrease in tensile strength, an increase in tensile stiffness and a decrease in strain to yield (%). This effect was attributable to enhanced diffusion bonding of the mat fiber intersections. The CNC fibers also increased mat stiffness, and reduced strain to yield in non-treated mats. The use of CNCs show potential for compounding into bulk polymer composites as a reinforcement filler, and also show promise for chemical crosslinking attributable to the -OH groups on both the PVA, in addition to esterification of the vinyl group, and CNC.

Method to reinforce polylactic acid with cellulose nanofibers via a polyhydroxybutyrate carrier system.

The elastic moduli of PLA reinforced with 5 and 10wt.% CNF with the carrier, at a frequency (ω) of 0.07, were 67% and 415% higher, respectively, than that of neat PLA. The shear viscosity at a shear rate of 0.01 (η0.01) for PLA+10wt.% CNF was 32% higher than that of the neat PLA matrix. The η0.01 of PLA reinforced with 5wt.% CNF and the PHB carrier was similar to neat PLA. The tensile and flexural moduli of elasticity of the nanocomposites continuously increased with increased CNF loading. The results of the mechanical property measurements are in accordance with the rheological data. The CNF appeared to be better dispersed (less-aggregated nanofibers) in the PLA reinforced with 5wt.% CNF and the PHB carrier. Possible applications for the composites studied in this research are packaging materials, construction materials, and auto parts for interior applications.

Testing of various membranes for use in a novel sediment porewater isolation chamber for infaunal invertebrate exposure to PCBs.

In benthic sediment bioassays, determining the relative contribution to exposure by contaminants in overlying water, porewater, and sediment particles is technically challenging. The purpose of the present study was to assess the potential for membranes to be utilized as a mechanism to allow freely dissolved hydrophobic organic contaminants into a pathway isolation exposure chamber (PIC) while excluding all sediment particles and dissolved organic carbon (DOC). This investigation was conducted in support of a larger effort to assess contaminant exposure pathways to benthos. While multiple passive samplers exist for estimating concentrations of contaminants in porewater such as those using solid-phase micro extraction (SPME) and polyoxymethylene (POM), techniques to effectively isolate whole organism exposure to porewater within a sediment system are not available. We tested the use of four membranes of different pore sizes (0.1-1.2µm) including nylon, polycarbonate, polyethylsulfone, and polytetrafluoroethylene with a hydrophilic coating. Exposures included both diffusion of radiolabeled and non-labeled contaminants across membranes from aqueous, sediment slurry, and whole sediment sources to assess and evaluate the best candidate membrane. Data generated from the present study was utilized to select the most suitable membrane for use in the larger bioavailability project which sought to assess the relevance of functional ecology in bioavailability of contaminated sediments at remediation sites. The polytetrafluoroethylene membrane was selected for use in the PIC, although exclusion of dissolved organic carbon was not achieved.