Atmospheric methane (CH 4) is a potent greenhouse gas, and its mole fraction has more than doubled since the preindustrial era 1. Fossil fuel extraction and use are among the largest anthropogenic sources of CH 4 emissions, but the precise magnitude of these contributions is a subject of debate 2,3. Carbon-14 in CH 4 (14 CH 4) can be used to distinguish between fossil (14 C-free) CH 4 emissions and contemporaneous biogenic sources; however, poorly constrained direct 14 CH 4 emissions from nuclear reactors have complicated this approach since the middle of the 20th century 4,5. Moreover, the partitioning of total fossil CH 4 emissions (presently 172 to 195 teragrams CH 4 per year) 2,3 between anthropogenic and natural geological sources (such as seeps and mud volcanoes) is under debate; emission inventories suggest that the latter account for about 40 to 60 teragrams CH 4 per year 6,7. Geological emissions were less than 15.4 teragrams CH 4 per year at the end of the Pleistocene, about 11,600 years ago 8 , but that period is an imperfect analogue for present-day emissions owing to the large terrestrial ice sheet cover, lower sea level and extensive permafrost. Here we use preindustrial-era ice core 14 CH 4 measurements to show that natural geological CH 4 emissions to the atmosphere were about 1.6 teragrams CH 4 per year, with a maximum of 5.4 teragrams CH 4 per year (95 per cent confidence limit)-an order of magnitude lower than the currently used estimates. This result indicates that anthropogenic fossil CH 4 emissions are underestimated by about 38 to 58 teragrams CH 4 per year, or about 25 to 40 per cent of recent estimates. Our record highlights the human impact on the atmosphere and climate, provides a firm target for inventories of the global CH 4 budget, and will help to inform strategies for targeted emission reductions 9,10. 14 CH 4 emissions from nuclear power plants 4,5. By contrast, palaeoatmospheric 14 CH 4 measurements from ice cores offer a direct constraint on natural geological CH 4 emissions without these complications. Whereas geological CH 4 emissions have the potential to change on tectonic-and glacial-cycle timescales 14 , they have very probably been constant over the past few centuries. The preindustrial-era emission estimates can therefore be applied to the modern CH 4 budget with confidence. Ice core 14 CH 4 analysis is challenging owing to both the very large sample requirement (~1,

Novel mesoporous tungsten trioxide films with enhanced incident photon-to-current conversion efficiencies have been prepared by a sol−gel route from an aqueous precursor solution containing peroxopolytungstic acid (PPTA). For films heated in air at 500 °C, it was found that film texture depended in a precise and reproducible manner on adjustment of the pH of this precursor solution by addition of a small volume of a selected mineral acid. Mesoporous micrometer-thick transparent films were obtained from PPTA without pH adjustment while mesoporous semi-transparent films resulted when the pH was lowered. The transparent films had specific surface areas of 18 m2/g, average pore diameters of 7.3 nm, and average crystallite sizes of 30 nm. The semi-transparent films possessed specific surface areas of 30 m2/g, average pore diameters of 12.5 nm, and average crystallite diameters of 17 nm. In the case of the semi-transparent films, electron microscopy indicated that the fundamental crystallites formed part of larger 200−300 nm aggregates which were in turn interconnected to form an open micrometer-length scale porous network. The transparent films did not show this type of porous hierarchy with the absence of micrometer-scale porosity. Photoelectrochemical studies of the films indicated that the hierarchical semi-transparent films exhibited a considerably enhanced photo-response relative to transparent films due to increases in both the interface area and light scattering. After calcination of the semi-transparent films at 500 °C, anodic photocurrents up to an equivalent of 1.4 mA/cm2 under Air Mass 1.5 equivalent solar irradiation were measured. Our results suggest that film texture is a major factor in determining the performance of the films, and the method reported here provides a simple and convenient means for modulation of this texture.

Objectives The aim of this study was to investigate factors affecting ablative efficiency of high intensity focused ultrasound (HIFU) for adenomyosis. Materials and methods In all, 245 patients with adenomyosis who underwent ultrasound guided HIFU (USgHIFU) were retrospectively reviewed. All patients underwent dynamic contrast-enhanced magnetic resonance imaging (MRI) before and after HIFU treatment. The non-perfused volume (NPV) ratio, energy efficiency factor (EEF) and greyscale change were set as dependent variables, while the factors possibly affecting ablation efficiency were set as independent variables. These variables were used to build multiple regression models. Results A total of 245 patients with adenomyosis successfully completed HIFU treatment. Enhancement type on T1 weighted image (WI), abdominal wall thickness, volume of adenomyotic lesion, the number of hyperintense points, location of the uterus, and location of adenomyosis all had a linear relationship with the NPV ratio. Distance from skin to the adenomyotic lesion's ventral side, enhancement type on T1WI, volume of adenomyotic lesion, abdominal wall thickness, and signal intensity on T2WI all had a linear relationship with EEF. Location of the uterus and abdominal wall thickness also both had a linear relationship with greyscale change. Conclusion The enhancement type on T1WI, signal intensity on T2WI, volume of adenomyosis, location of the uterus and adenomyosis, number of hyperintense points, abdominal wall thickness, and distance from the skin to the adenomyotic lesion's ventral side can all be used as predictors of HIFU for adenomyosis.

The acid effect on the aggregation of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymers EO(20)PO(70)EO(20) has been investigated by transmission electron microscopy (TEM), particle size analyzer (PSA), Fourier transformed infrared, and fluorescence spectroscopy. The critical micellization temperature for Pluronic P123 in different HCl aqueous solutions increases with the increase of acid concentration. Additionally, the hydrolysis degradation of PEO blocks is observed in strong acid concentrations at higher temperatures. When the acid concentration is low, TEM and PSA show the increase of the micelle mean diameter and the decrease of the micelle polydispersity at room temperature, which demonstrate the extension of EO corona and tendency of uniform micelle size because of the charge repulsion. When under strong acid conditions, the aggregation of micelles through the protonated water bridges was observed.