Most randomized controlled trials of venous thromboembolism prophylaxis have focused on reduction of deep vein thrombosis, predominantly asymptomatic deep vein thrombosis, detected on imaging. We ...aimed to estimate the effects of graduated compression stockings on venous thromboembolism events, survival, and functional status at 6 months after stroke.
The CLOTS Trials adopted an international multicentre, parallel group design, with central randomization and a 1:1 treatment allocation. In CLOTS Trial 1, 2518 immobile stroke patients were allocated thigh-length graduated compression stockings or not, and in CLOTS trial 2, 3014 to thigh-length or below-knee graduated compression stockings. We measured vital status, Oxford Handicap Scale, and quality of life (EQ5D-3 L) at 6 months.
We compared survival in patients enrolled in Trials 1 and 2 with a Cox proportional hazards model, including variables included in our minimization algorithm. In both trials, allocation to thigh-length graduated compression stockings was associated with a very slight, but nonsignificant, increased hazard of death in the first 6 months (Trial 1: hazard ratio, 1.087; 95% confidence interval, 0.913-1.295; and Trial 2: hazard ratio, 1.037; 95% confidence interval, 0.892-1.205). There were no statistically significant differences in venous thromboembolism events, Oxford Handicap Scale, or EQ5D-3 L between the treatment groups in CLOTS Trials 1 or 2.
Although underpowered to detect clinically important effects on long-term outcomes, our results effectively exclude a >10% relative reduction in the hazard of death within 6 months associated with the use of thigh-length stockings. No other long-term benefits were apparent.
Deep vein thrombosis (DVT) is an important complication of stroke. Guidelines recommend that DVT prophylaxis should be guided by an assessment of the individual patient's risk. The authors aimed to ...develop and test models to predict DVT risk.
The Clots in Legs Or sTockings after Stroke (CLOTS) Trial 1 randomised 2518 immobile patients with acute stroke to thigh-length graduated compression stockings (GCS) or no GCS and CLOTS Trial 2 randomised 3114 to thigh-length or below-knee GCS. The authors collected potential predictive variables at baseline and detected DVTs with compression duplex ultrasound scans at about 7-10 days and 25-30 days. The authors developed models with logistic regression to predict DVT in 1242 Trial 2 patients who had two scans and tested the models in the 1422 Trial 1 patients with two scans by estimating the area under the receiver operating characteristic curve (AUC).
168 (11.8%) patients in Trial 1 and 122 (9.8%) in Trial 2 had proximal DVTs. A model based on the Trial 2 cohort contained four of the 12 baseline variables: dependent before stroke (OR=3.62, 95% CI 2.15 to 6.08), unable to lift arms off bed (OR 1.89, 95% CI 1.23 to 2.90), history of DVT/pulmonary embolism (OR 3.69, 95% CI 1.98 to 6.88) and diabetes (OR 0.55, 95% CI 0.30 to 0.99). The AUC in the development cohort was 0.65 but only 0.57, 95% CI (0.53 to 0.61) in the Trial 1 cohort, indicating poor discrimination.
Unfortunately, models based on clinical factors alone discriminate poorly between immobile patients with stroke at high and low risk, and would not facilitate individual tailoring of DVT prophylaxis strategies.
In 2003 the Scottish Health Service Central Legal Office was consulted on the requirement to supply an alternative to natural rubber latex gloves for healthcare professionals within NHS Lothian ...University Hospitals Trust. Counsel stated that as latex is now accepted as being hazardous to health, employers must prove the statutory defence in Regulation 7(1) of the Control of Substances Hazardous to Health Regulations (HSE 2002). Counsel also stated that, as there are now adequate alternatives to latex gloves, NHS employers would have an indefensible position if no attempt was made to supply alternatives.
Approximately 80,000 patients each year are admitted to U.K. hospitals with an acute stroke and are immobile. At least 10% will develop a proximal deep vein thrombosis in the first month and 1.5% a ...pulmonary embolus. Although hydration, antiplatelet treatment and early mobilisation may reduce the risk of deep vein thrombosis, there are currently no preventive strategies which have been clearly shown to be both effective and safe. Anticoagulation increases the risks of bleeding and compression stockings are ineffective. Systematic reviews of small randomized trials of intermittent pneumatic compression have shown that this reduces the risk of deep vein thrombosis in patients undergoing surgery, but that there are few data concerning its use after stroke. The CLOTS trial 3 aims to determine whether, compared with best medical care, best medical care plus intermittent pneumatic compression in immobile stroke patients reduces the risk of proximal deep vein thrombosis.
CLOTS Trial 3 is a parallel group multicentre trial; with centralized randomisation (minimisation) to ensure allocation concealment. Over 80 centres in the U.K. will recruit 2800 immobile stroke patients within the first 3 days of their hospital admission. Patients will be allocated to best medical care or best medical care plus intermittent pneumatic compression. Ultrasonographers will perform a Compression Duplex Ultrasound Scan to detect deep vein thrombosis in each treatment group at about 7-10 days and 25-30 days. The primary outcome cluster includes symptomatic or asymptomatic deep vein thrombosis in the popliteal or femoral veins detected on either scan. Patients are then followed up by postal or telephone questionnaire at 6 months from randomisation to detect later symptomatic deep vein thrombosis and pulmonary emboli and to establish their functional outcome (Oxford handicap scale) and quality of life (EQ5D-3 L). The ultrasonographers performing the scans are blinded to treatment allocation, whereas the patients and caregivers are not. The trial has 90% power to detect a 4% absolute difference in risk of the primary outcome and includes a health economic analysis.
The trial started recruitment in Dec 2008 and will complete recruitment during 2012. It will report results in 2013.
ISRCTN: ISRCTN93529999.
ABSTRACT
Transiting exoplanets orbiting young nearby stars are ideal laboratories for testing theories of planet formation and evolution. However, to date only a handful of stars with age <1 Gyr have ...been found to host transiting exoplanets. Here we present the discovery and validation of a sub-Neptune around HD 18599 , a young (300 Myr), nearby (d = 40 pc) K star. We validate the transiting planet candidate as a bona fide planet using data from the TESS , Spitzer , and Gaia missions, ground-based photometry from IRSF , LCO , PEST , and NGTS , speckle imaging from Gemini, and spectroscopy from CHIRON , NRES , FEROS , and Minerva-Australis . The planet has an orbital period of 4.13 d , and a radius of 2.7 R⊕ . The RV data yields a 3-σ mass upper limit of 30.5 M⊕ which is explained by either a massive companion or the large observed jitter typical for a young star. The brightness of the host star (V∼9 mag) makes it conducive to detailed characterization via Doppler mass measurement which will provide a rare view into the interior structure of young planets.
Stainless Steel 304 is being investigated for accident tolerant claddings. In this investigation, we use multi-modal characterization to evaluate oxidation under laboratory air versus 100% steam at ...1200 ºC for 2 h. Air oxidation features Fe(NiMn)O4, Fe3O4, Fe(3−x)CrxO4, and Cr2O3. Steam oxidation produces a dual layer, containing Fe2O3-enriched porous outer layer and sub-surface matrix of Fe3O4/Fe(3−x)CrxO4 with SiO2/Fe(3−x)SixO4. From these findings, we postulate the oxidation mechanism. Arrangement of oxidation products in air corroborates with anticipated diffusion behavior, except Cr2O3. However, arrangement in steam deviates due to presumably intergranular interactions with H2O, resulting in the sub-surface matrix.
Display omitted
•SS304 was exposed to air and steam at 1200 °C for 2 h.•Oxidation in steam gave rise to a dual Fe-enriched surface layer.•Oxidation in air gave rise to a Fe(NiMn)O4, Fe3O4, Fe(3−x)CrxO4, and Cr2O3 surface layer.•Results on steam oxidation somewhat agree with historical data reported by Bittel, et al. and Ishida, et al.
Display omitted
•APMT and T91 exposed to air and steam at 1200 °C for 2 h.•APMT formed α-Al2O3 layer that was thicker after exposure to air than steam.•T91 formed mixed, non-passivating Fe-Cr layer ...in both environments.•Major oxidation products in T91 are Fe3O4, FeO and Fe(3-x)CrxO4.
Limited information is available on the oxidation mechanism of accident tolerant claddings (ATC) Kanthal APMT and T91 at the onset of beyond design-basis accident (BDBA) conditions. We characterized the surface of these ATC alloys after steam and air exposure at 1200 °C for 2 h, defining the oxidation mechanism. Thickness and composition were analyzed with microscopy, Raman spectroscopy, and synchrotron diffraction. Our results demonstrate that APMT forms a compact and homogeneous α-Al2O3 layer when exposed to air or steam. T91 forms a heterogeneous porous layer, containing a mixture of Cr- and Fe-based oxides, whose composition changes with the exposure environment.
Understanding the performance of cladding materials during a loss-of-coolant accident scenario is crucial for developing next-generation accident tolerant nuclear fuel rod claddings. We describe a ...multi-modal approach combining synchrotron-based diffraction, and Raman spectroscopy with nano-scale electron microscopy techniques for investigating oxidation of Inconel 600 (A600) in steam and air environments at 1200 °C for 2 h. We report that A600 exposed to steam develops a Cr2O3-enriched surface layer while a mixed phase oxide layer containing NiFe2O4, Cr2O3, Fe3O4 and Fe(3–x)CrxO4 is formed in air. Mechanism of oxidation for A600 in air and steam environments is discussed.
Display omitted
•A600 was exposed to air and steam at 1200 °C for 2 h.•Oxidation in steam gave rise to a Cr2O3-enriched surface layer.•Oxidation in air gave rise to NiFe2O4 surface layer.•Based on extent of oxidation, A600 exhibited superior performance to Zircaloy-2.
Long-term data of local bird communities have shown changes over the past few decades due to anthropogenic pressures, especially in temperate regions. However, we lack information on bird community ...change in many parts of the world, including hot and dry, desert areas that are also exposed to human activities. We analysed unique time series data of wetland bird abundance spanning over 26 years (1987–2012) collected at an important stopover for long-distance migratory birds, Taunsa Barrage Wildlife Sanctuary, a Ramsar Site in Pakistan. During the monitoring period, species richness of the community had increased over time, but there had also been community turnover. Many species (25/58) had increased in abundance while a few had decreased (4/58). We also found that winter and spring temperatures were positively associated with abundance changes at a community-level, suggesting that some species might have benefited from increasingly warmer temperatures. We assessed whether species attributes such as body size, diet preferences, habitat preference, temperature niche, and range size explained intraspecific variation in species’ population trends. However, most of the species attributes were not important. There was some indication that larger-bodied species had increased more than smaller-bodied species but there was no evidence of a community shift to more generalist species. Given anthropogenic change in this region, our findings suggest that many species are able to persist at this site but on-going monitoring and management of this wetland is essential.
PDF
