655 research outputs found
The Impact of Shoreline Stabilization on Sediment Supply and Ecogeomorphology: Assessing Marsh Response to Altered Wave Energies, Lake Borgne, Louisiana
Shoreline protection structures are a common response to lateral erosion in marshes, but limited studies exist on how they influence sediment supply and the resulting ecogeomorphology. This study investigates the impacts of marine mattresses, geotextile cages filled with riprap, in Lake Borgne, LA. A field study was conducted during cold front passages at a site with marine mattresses and a proximal control site without, collecting measurements of water depth, wave energy, lateral erosion, sediment accumulation, vegetation, and sediment characteristics. Wetlands with marine mattresses attenuated waves more than their natural marsh edge counterparts, which have limited conditions favorable for sedimentation. However, the lateral position of the marsh was maintained, while the control site eroded at an average rate of 1.7 meters per year. Water content, organic matter, bulk density, salinity, and pH were similar between the sites, but the marine mattress site was lower in elevation and contained finer sediments
Low-risk prostate cancer selected for active surveillance with negative MRI at entry: can repeat biopsies at 1 year be avoided? A pilot study
Purpose: In patients considered for active surveillance (AS), the use of MRI and targeted biopsies (TB) at entry challenges the approach of routine “per protocol” repeat systematic biopsies (SB) at 1 year. This pilot study aimed to assess whether an approach of performing repeat biopsies only if PSA kinetics are abnormal would be safe and sufficient to detect progression. /
Methods: Prospective single-centre study of 149 patients on AS with low-risk PCa, a negative MRI at entry, followed for a minimum of 12 months between 01/2007 and 12/2015. Group 1 (n = 78) patients had per-protocol 12-month repeat SB; group 2 (n = 71) patients did not. Surveillance tests for tumour progression were for both groups: for cause SB and MRI-TB biopsies if PSA velocity (PSA-V) > 0.75 ng/ml/year, or PSA doubling time (PSADT) < 3 years. The main objectives are to compare the 2-year rates of tumour progression and AS discontinuation between groups. The secondary objectives are to estimate the diagnostic power of PSA-V and PSA-DT, to predict the risk of tumour progression. /
Results: Overall, 21 out of 149 patients (14.1%) showed tumour progression, 17.1% for group 1 and 12.3% for group 2, and 31 (21.2%) discontinued AS at 2 years. There was no difference between the 2 groups (p = 0.56). The area under the PSA-V and PSADT curves to predict tumour progression was 0.92 and 0.83, respectively. /
Conclusions: We did not find any significant difference for progression and AS discontinuation rate between the 2 groups. The PSA kinetic seems accurate as a marker of tumour progression. These results support the conduct of a multi-centre prospective trial to confirm these findings
Primary beam effects of radio astronomy antennas -- II. Modelling the MeerKAT L-band beam
After a decade of design and construction, South Africa's SKA-MID precursor
MeerKAT has begun its science operations. To make full use of the widefield
capability of the array, it is imperative that we have an accurate model of the
primary beam of its antennas. We have taken available L-band full-polarization
'astro-holographic' observations of three antennas and a generic
electromagnetic simulation and created sparse representations of the beams
using principal components and Zernike polynomials. The spectral behaviour of
the spatial coefficients has been modelled using discrete cosine transform. We
have provided the Zernike-based model over a diameter of 10 deg averaged over
the beams of three antennas in an associated software tool (EIDOS) that can be
useful in direction-dependent calibration and imaging. The model is more
accurate for the diagonal elements of the beam Jones matrix and at lower
frequencies. As we get more accurate beam measurements and simulations in the
future, especially for the cross-polarization patterns, our pipeline can be
used to create more accurate sparse representations of MeerKAT beams.Comment: 16 pages, 18 figures. This is a pre-copyedited, author-produced PDF
of an article accepted for publication in MNRAS following peer review. The
version of record [K. M. B. Asad et al., 2021] is available online at:
https://doi.org/10.1093/mnras/stab10
TOOKAD® Soluble focal therapy: pooled analysis of three phase II studies assessing the minimally invasive ablation of localized prostate cancer
Purpose:
To evaluate the 6-month effects of the recommended drug and light dosage in focal vascular-targeted photodynamic therapy (VTP) using TOOKAD® Soluble in patients with localized prostate cancer (LPCa).
Methods:
We performed a pooled analysis of 117 men with LPCa, PSA <10 ng/mL, and Gleason score ≤7 (3 + 4), from 3 studies who received a 10-min intravenous infusion of a single dose of 4 mg/kg TOOKAD® Soluble, activated by a 753-nm light at 200 J/cm delivered in the prostate by transperineal fibres under transrectal ultrasound guidance. Primary endpoint was 6-month negative biopsies in the treated lobe(s). PSA was measured at month 1, 3, and 6. Magnetic resonance imaging was performed at day 7, month 3, and 6. International Prostate Symptom Score (IPSS), International Index of Erectile Function (IIEF-5) and adverse events were reported at day 7, month 1, 3, and 6.
Results:
Month 6 negative biopsy rate was 68.4 % in the overall evaluable population (N = 114) and 80.6 % for patients treated by hemiablation with light density index (LDI) ≥ 1 (N = 67). Mean prostate necroses at week-1 were 76.5 and 86.3 %, respectively. In both groups, PSA levels at month 6 decreased by 2.0 ng/mL. Small changes from baseline for IPSS and IIEF-5 indicated a slight improvement in urinary function and a slight deterioration in sexual function.
Conclusions:
Focal VTP treatment with TOOKAD® Soluble at 4 mg/kg and 200 J/cm resulted in a negative 6-month biopsy rate of 68.4 % for the whole population and 80.6 % for patients treated by hemiablation with LDI ≥ 1. The treatment was well tolerated. Two phase III studies will reach completion in early 2015
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Solubilities of Ethylene and Carbon Dioxide Gases in Lithium-Ion Battery Electrolyte
During Li-ion battery operation, (electro)chemical side reactions occur within the cell that can promote or degrade performance. These complex reactions produce byproducts in the solid, liquid, and gas phases. Studying byproducts in these three phases can help optimize battery lifetimes. To relate the measured gas-phase byproducts to species dissolved in the liquid-phase, equilibrium proprieties such as the Henry's law constants are required. The present work implements a pressure decay experiment to determine the thermodynamic equilibrium concentrations between the gas and liquid phases for ethylene (C2H4) and carbon dioxide (CO2), which are two gases commonly produced in Li-ion batteries, with an electrolyte of 1.2 M LiPF6 in 3:7 wt/wt ethylene carbonate/ethyl methyl carbonate and 3 wt % fluoroethylene carbonate (15:25:57:3 wt % total composition). The experimentally measured pressure decay curve is fit to an analytical dissolution model and extrapolated to predict the final pressure at equilibrium. The relationship between the partial pressures and concentration of dissolved gas in electrolyte at equilibrium is then used to determine Henry's law constants of 2.0 × 104 kPa for C2H4 and k CO2 = 1.1 × 104 kPa for CO2. These values are compared to Henry's law constants predicted from density functional theory and show good agreement within a factor of 3
Determination of optimal drug dose and light dose index to achieve minimally invasive focal ablation of localised prostate cancer using WST11-vascular-targeted photodynamic (VTP) therapy
Objective:
To determine the optimal drug and light dose for prostate ablation using WST11 (TOOKAD® Soluble) for vascular-targeted photodynamic (VTP) therapy in men with low-risk prostate cancer.
Patients and Methods:
In all, 42 men with low-risk prostate cancer were enrolled in the study but two who underwent anaesthesia for the procedure did not receive the drug or light dose. Thus, 40 men received a single dose of 2, 4 or 6 mg/kg WST11 activated by 200 J/cm light at 753 nm. WST11 was given as a 10-min intravenous infusion. The light dose was delivered using cylindrical diffusing fibres within hollow plastic needles positioned in the prostate using transrectal ultrasonography (TRUS) guidance and a brachytherapy template. Magnetic resonance imaging (MRI) was used to assess treatment effect at 7 days, with assessment of urinary function (International Prostate Symptom Score [IPSS]), sexual function (International Index of Erectile Function [IIEF]) and adverse events at 7 days, 1, 3 and 6 months after VTP. TRUS-guided biopsies were taken at 6 months.
Results:
In all, 39 of the 40 treated men completed the follow-up. The Day-7 MRI showed maximal treatment effect (95% of the planned treatment volume) in men who had a WST11 dose of 4 mg/kg, light dose of 200 J/cm and light density index (LDI) of >1. In the 12 men treated with these parameters, the negative biopsy rate was 10/12 (83%) at 6 months, compared with 10/26 (45%) for the men who had either a different drug dose (10 men) or an LDI of <1 (16). Transient urinary symptoms were seen in most of the men, with no significant difference in IPSS score between baseline and 6 months after VTP. IIEF scores were not significantly different between baseline and 6 months after VTP.
Conclusion:
Treatment with 4 mg/kg TOOKAD Soluble activated by 753 nm light at a dose of 200 J/cm and an LDI of >1 resulted in treatment effect in 95% of the planned treatment volume and a negative biopsy rate at 6 months of 10/12 men (83%)
A panel of kallikrein markers can predict outcome of prostate biopsy following clinical work-up: an independent validation study from the European Randomized Study of Prostate Cancer screening, France
<p>Abstract</p> <p>Background</p> <p>We have previously shown that a panel of kallikrein markers - total prostate-specific antigen (PSA), free PSA, intact PSA and human kallikrein-related peptidase 2 (hK2) - can predict the outcome of prostate biopsy in men with elevated PSA. Here we investigate the properties of our panel in men subject to clinical work-up before biopsy.</p> <p>Methods</p> <p>We applied a previously published predictive model based on the kallikrein panel to 262 men undergoing prostate biopsy following an elevated PSA (≥ 3 ng/ml) and further clinical work-up during the European Randomized Study of Prostate Cancer screening, France. The predictive accuracy of the model was compared to a "base" model of PSA, age and digital rectal exam (DRE).</p> <p>Results</p> <p>83 (32%) men had prostate cancer on biopsy of whom 45 (54%) had high grade disease (Gleason score 7 or higher). Our model had significantly higher accuracy than the base model in predicting cancer (area-under-the-curve [AUC] improved from 0.63 to 0.78) or high-grade cancer (AUC increased from 0.77 to 0.87). Using a decision rule to biopsy those with a 20% or higher risk of cancer from the model would reduce the number of biopsies by nearly half. For every 1000 men with elevated PSA and clinical indication for biopsy, the model would recommend against biopsy in 61 men with cancer, the majority (≈80%) of whom would have low stage <it>and </it>low grade disease at diagnosis.</p> <p>Conclusions</p> <p>In this independent validation study, the model was highly predictive of prostate cancer in men for whom the decision to biopsy is based on both elevated PSA and clinical work-up. Use of this model would reduce a large number of biopsies while missing few cancers.</p
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