Description: Logging-while-drilling (LWD) and wireline log (CWL) data were acquired during China's second gas hydrate drilling expedition (GMGS-2) in the east of Pearl River Mouth Basin, South China Sea. Disseminated and massive gas hydrates deposits were found at different sites. Gas hydrate-bearing lithologies identified from the sample coring included the fine-grained sediments and coarse-grained sediments. LWD logs from Site GMGS2-08 indicate significant gas hydrate in clay-bearing sediments including two layers with massive gas hydrate with a bulk density near to 1.08 g/cm3. High electrical resistivities with a range of 2.5–2000.0 Ω m and high P-wave velocities are simultaneously observed in the hydrate-bearing sediments. The average gas hydrate saturation estimated from the pore water freshing analysis ranges from 45 to 55% of the pore space. Buried carbonate layers above the massive gas hydrate deposit discovered at Sites GMGS2-08 indicate that the formations are likely to have formed initially at the surface and then were buried. Significant high amplitude seismic anomalies, discontinuous bottom simulating reflection (BSR) and blanking zone are detected in the drilling zone. The hydrate-bearing sediments predominantly consist of silty clay and limestone grains in which the gas hydrates are deposited primarily in the form of laminated, massive, veins or nodule. The gas hydrates occurrences are subjected to the sediment lithology, new tectonic activities, migration of fluid and gas and also the factors such as heat flow, salinity and time which affect the nucleation of gas hydrates. Its natural morphologies present massive, laminated, nodular, nugget and disseminated, of which the former four often formed in shallow fault, inter-layer's weak cementation zone and on the seabed. The “buried” gas hydrates with high saturation are good zones for gas hydrate exploitation.

Description: We present results from 30 quantitative degassing experiments of pressure core sections collected during The University of Texas-Gulf of Mexico 2-1 (UT-GOM2-1) Hydrate Pressure Coring Expedition at Green Canyon Block 955 in the deep-water Gulf of Mexico as part of The University of Texas at Austin–US Department of Energy Deepwater Methane Hydrate Characterization and Scientific Assessment. The hydrate saturation (Sh), the volume fraction of the pore space occupied by hydrate, is 79% to 93% within sandy silt beds (centimeters to meters in thickness) between 413 and 442 m below seafloor in 2032 m water depth. Sandy silt intervals are characterized by high compressional wave velocity (Vp) (2515–3012 m s−1) and are interbedded with clayey silt sections that have lower Sh (2%–35%) and lower Vp (1684–2023 m s−1). Clayey silt intervals are composed of thin laminae of silts with high Sh within clay-rich intervals containing little to no hydrate. Degassing of single-lithofacies sections reveals higher-resolution variation in Sh than is possible to observe in well logs; however, the average Sh of 64% through the reservoir is similar to well log estimates. Gas recovered from the hydrates during these experiments is composed almost entirely of methane (99.99% CH4, 〈100 ppm C2H6 on average), with an isotopic composition (δ13C: −60.4‰ and −63.6‰ Vienna Peedee belemnite and δ2H: −178.2‰ and −179.0‰ Vienna standard mean ocean water) that suggests the methane is primarily from a microbial source. A subset of six degassing experiments performed using very small pressure decrements indicates that the salinity within these samples is close to the average seawater concentration, suggesting that hydrate either formed slowly or formed during a rapid event at least tens of thousands of years before present.

Description: Aims Giant cell tumour of bone (GCTB) is a neoplasm predominantly of long bones characterised by the H3F3A mutation G34W. Conventional diagnostic is challenged by the tumour's giant cell-rich morphology, which overlaps with other giant cell containing lesions of the bone. Recently, a monoclonal antibody specific for the H3F3A mutation has been generated. Our aim was to test this antibody on a cohort of giant cell containing lesions. Methods and Results We used the antibody for analysis of 22 H3F3A-mutated GCTB, including two patients with recurrences; for comparison we analysed a cohort of 36 H3F3A-wild-type giant cell-rich lesions of the bone and soft tissue, containing one brown tumour, six aneurysmal bone cysts, six chondroblastomas, five non-ossifying-fibromas, two fibrous dysplasias, nine tenosynovial giant cell tumours, one giant cell-rich sarcoma and six osteosarcomas. Furthermore, we included one GCTB with two recurrences and lung metastases; the patient was treated with the anti-RANK ligand denosumab. We show that all 23 H3F3A-mutated GCTB display strong nuclear H3.3 G34W staining in the neoplastic component, while the osteoclastic giant cells are negative. 36 H3F3A-wild-type lesions are negative. The GCTB treated with denosumab revealed a reduction in the H3.3 G34W-positive tumour cells and a decrease in osteoclastic giant cells accompanied by matrix and osteoid formation. Conclusions We conclude that positive H3.3 G34W staining is a specific and sensitive method for detection of H3F3A-mutated GCTB. Denosumab treatment leads to a pathomorphosis of the lesion characterised by matrix and osteoid producing H3.3 G34W-negative stromal cells. This article is protected by copyright. All rights reserved.