Abstract
Hydrous minerals in subducted crust can transport large amounts of water into Earth's deep mantle. Our laboratory experiments revealed the surprising pressure-induced chemistry that, when ...water meets iron at the core–mantle boundary, they react to form an interlayer with an extremely oxygen-rich form of iron, iron dioxide, together with iron hydride. Hydrogen in the layer will escape upon further heating and rise to the crust, sustaining the water cycle. With water supplied by the subducting slabs meeting the nearly inexhaustible iron source in the core, an oxygen-rich layer would cumulate and thicken, leading to major global consequences in our planet. The seismic signature of the D″ layer may echo the chemical complexity of this layer. Over the course of geological time, the enormous oxygen reservoir accumulating between the mantle and core may have eventually reached a critical eruption point. Very large-scale oxygen eruptions could possibly cause major activities in the mantle convection and leave evidence such as the rifting of supercontinents and the Great Oxidation Event.
SUMMARY
Submucosal tunneling endoscopic resection (STER) of subepithelial tumors (SETs) originating from the muscularis propria (MP) layer in the cardia is rarely performed due to the difficulty of ...creating a submucosal tunnel for resection. The aim of this study is to evaluate the feasibility of STER using methylene-blue guidance for SETs originating from the MP layer in the cardia. From January 2012 to December 2014, 56 patients with SETs originating from the MP layer in the cardia were treated with STER using methylene-blue guidance. The complete resection rate and adverse event rate were the main outcome measurements. Successful complete resection by STER was achieved in all 56 cases (100%). The median size of the tumor was 1.8 cm. Nine patients (15.3%) had adverse events including subcutaneous emphysema, pneumoperitoneum, pneumothorax, and pleural effusion. These nine patients recovered successfully after conservative treatment without endoscopic or surgical intervention. No residual or recurrent tumors were detected in any patient during the follow-up period (median, 25 months). The adverse event rate was significantly higher for tumors originating in the deeper MP layers (46.7%) than in the superficial MP layers (4.9%) (P < 0.05), differed significantly according to tumor size (5.4% for tumors < 2.0 cm vs. 36.8% for tumors ≥ 2.0 cm; P < 0.05), and also differed significantly in relation to the tumor growth pattern (4.1% for the intraluminal growth vs. 100% for the extraluminal growth; P < 0.001). STER using methylene-blue guidance appears to be a feasible method for removing SETs originating from the MP layer in the cardia.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
In large gravel‐bed rivers, bed material transport estimation is challenging since theoretically based formulas often fail to accurately predict sediment fluxes, and it is difficult to carry out ...field measurements. A viable alternative to direct measurement is provided by the virtual velocity approach representing a hybrid solution to calculate the bed material transport based on a theoretical framework and use of tracers. This work aims to improve the methodology and to assess the role of input factors through a case‐study application carried out in the Parma River (Italy). Two tracer types and scour chains were deployed at four sections. Data on water level, transport processes, particle travel distances, and active layers were collected over 17 months and 6 events. The transport that occurred during two events was calculated applying different configurations taking in account for several input factors (i.e., grain size, water stage, and topography). Applying simple or more complex configurations led to significant differences in transport estimates: In relation to channel morphodynamics, different factors (e.g., variability of water level within the cross section in multithread channels) play a key role on transport processes. Results indicate that it is crucial to collect and process field data developing reach‐specific transport rating curves and to combine different type of tracers for monitoring the clast displacement lengths. Based on the methodological improvements and sensitivity analysis addressed in this study, we developed a decision tree in order to design future applications of the virtual velocity approach for estimating the bed material load in different gravel‐bed river contexts.
Key Points
The virtual velocity approach represents a viable alternative method to address the bed material load estimation in large gravel‐bed rivers
Identification of appropriate spatial scales and use of multiple tracer types represent two crucial methodological improvements
Seven data input configurations provide different transport estimates and insights about the sensitivity of the approach to different factors
No standard of care for mucosal melanoma (MM) in the adjuvant setting has been established. Meanwhile, relapse-free survival (RFS) is only ∼5 months after surgery alone. This phase II trial aimed to ...compare toripalimab versus high-dose interferon-α2b (HDI) as an adjuvant therapy for resected MM.
From July 2017 to May 2019, 145 patients with resected MM were randomized (1 : 1) to receive HDI (n = 72) or toripalimab (n = 73) for 1 year until disease relapse/distant metastasis, unacceptable toxicity, or withdrawal of consent. The primary endpoint was RFS. The secondary endpoints included distant metastasis-free survival (DMFS), overall survival (OS), and safety.
After a median follow-up of 26.3 months, the number of RFS, OS, and DMFS events was 51 versus 46, 33 versus 29, and 49 versus 44 in the toripalimab arm and the HDI arm, respectively. The median RFS was 13.6 95% confidence interval (CI) 8.31-19.02 months and 13.9 (95% CI 8.28-19.61) months in the toripalimab arm and the HDI arm, respectively. The DMFS was not significantly different between the two arms hazard ratio (HR) 1.00; 95% CI 0.65-1.54. The median OS was 35.1 months (95% CI 27.93 months-not reached) in the toripalimab arm, with no significant difference in all-cause death (HR 1.11, 95% CI 0.66-1.84) for the two arms. The median sums of the patients’ actual infusion doses were 3672 mg and 1054.5 MIU in the toripalimab arm and the HDI arm, respectively. The incidence of treatment-emergent adverse events with a grade ≥3 was much higher in the HDI arm than in the toripalimab arm (87.5% versus 27.4%).
Toripalimab showed a similar RFS and a more favorable safety profile than HDI, both better than historical data, suggesting that toripalimab might be the better treatment option. However, additional translational studies and better treatment regimens are still warranted to improve the clinical outcome of MM.
•This is the first study to compare toripalimab versus HDI as adjuvant therapy for resected MM.•In PD-L1-positive patients, the median RFS was ∼6 months longer in the toripalimab arm than in the HDI arm.•The incidence of TEAEs with a grade ≥3 was much higher in the HDI arm than in the toripalimab arm.•Both interventions have potential for MM; toripalimab might be the better treatment option.
General 2.5 power law of metallic glasses Zeng, Qiaoshi; Lin, Yu; Liu, Yijin ...
Proceedings of the National Academy of Sciences - PNAS,
02/2016, Letnik:
113, Številka:
7
Journal Article
Recenzirano
Odprti dostop
Metallic glass (MG) is an important new category of materials, but very few rigorous laws are currently known for defining its “disordered” structure. Recently we found that under compression, the ...volume (V) of an MG changes precisely to the 2.5 power of its principal diffraction peak position (1/q₁). In the present study, we find that this 2.5 power law holds even through the first-order polyamorphic transition of a Ce68Al10Cu20Co₂ MG. This transition is, in effect, the equivalent of a continuous “composition” change of 4f-localized “big Ce” to 4f-itinerant “small Ce,” indicating the 2.5 power law is general for tuning with composition. The exactness and universality imply that the 2.5 power law may be a general rule defining the structure of MGs.
Metallization of hydrogen as a key problem in modern physics is the pressure-induced evolution of the hydrogen electronic band from a wide-gap insulator to a closed gap metal. However, due to its ...remarkably high energy, the electronic band gap of insulating hydrogen has never before been directly observed under pressure. Using high-brilliance, high-energy synchrotron radiation, we developed an inelastic x-ray probe to yield the hydrogen electronic band information in situ under high pressures in a diamond-anvil cell. The dynamic structure factor of hydrogen was measured over a large energy range of 45 eV. The electronic band gap was found to decrease linearly from 10.9 to 6.57 eV, with an 8.6 times densification (ρ/ρ_{0}∼8.6) from zero pressure up to 90 GPa.
Research on factors affecting sediment regime in glacierized catchments under warming climates is still scarce despite its societal relevance. In particular, coarse bedload transport has never been ...quantitatively related to water runoff origin (snowmelt vs glacier melt), which provides important information on the role of different sediment sources (glaciers vs hillslopes and channel bed). Drawing on data from multiple spatial and temporal scales in a paradigmatic Alpine glacierized catchment, we show that glacier melt flows play a key role in coarse sediment transport dynamics. Bedload concentration measured during glacier melt flows is up to 6 orders of magnitude larger than during snowmelt. At the catchment scale and within the channel, however, minimal aggradation and degradation was detected over almost a decade. In addition, sedimentation rates at a hydropower weir, inferred from flushing frequency during the last four decades, are tightly associated to summer air temperature and not to precipitation trends, and most of sediment export occurred in July-August. However, sediment flushing frequency has been decreasing since the late 1990s despite very warm summers in the following decades. Collectively, these findings indicate that sediment is dominantly sourced from within glacier-covered areas and that transport rates are thus dictated by seasonal and multi-annual glacial dynamics. As glacier melt flows decrease due to ice mass loss, our results suggest that, for similar basins, a progressive shift from supply-limited (driven by glacier activity) to transport-limited (during rainfall-induced events) sediment transport will occur, disrupting the current near-equilibrium channel conditions.
•Hydrograph separation coupled to bedload measurements in a glacierized catchment.•Bedload during glacier melt up to 6 orders of magnitude larger than during snowmelt.•Decadal channel bed equilibrium despite large bedload yields from glaciers.•Sediment export statistically related to summer air temperatures and not to precipitation.•Sediment export peaked in late 1990s despite rising temperatures in 21st century.
•The paper provides a systematic study of the toughness of UHPFRC beam at various strain rates.•Field tests show variation of toughness of UHPFRC beam with various fibre volumes.•Performance of ...UHPFRC beam under impact loading can be simulated with good quality using numerical model.•Numerical model can provide toughness variation of UHPFRC beam without the influence due to random fibre orientation and distribution.
This paper provides a systematic study about toughness of ultra high performance fibre reinforced concrete (UHPFRC) in order to better understand the UHPFRC resistance under impact loading condition. UHPFRC beams containing various fibre volumes are tested under impact load at different strain rate. From the test results, the relationship between UHPFRC toughness and strain rate can be determined. Moreover, a numerical model of UHPFRC beam under impact load is developed and its performance is verified using test data. With developed UHPFRC model, the evolution of UHPFRC toughness can be better investigated.
Abstract The purpose of this study was to clarify the correlation between pre-treatment anterior disc displacement and mandibular stability after orthognathic and orthodontic treatment among patients ...with a skeletal class II malocclusion and without pre-treatment condylar resorption. Thirty-seven patients were included (7 male, 30 female). The mean length of follow-up was 6.76 ± 3.06 years. Patients with condylar resorption before treatment were excluded. Magnetic resonance images and lateral cephalometric radiographs were taken before treatment (T0), after treatment (T1), and at follow-up (T2). Patients were classified according to the degree of disc displacement: −10–10° ‘normal’, 11–50° ‘slight to mild’, ≥51° ‘moderate to severe’. Results showed the condyle moved posterosuperiorly after treatment, and then moved anteriorly to a more concentric location during the long follow-up period. Condylar movement was found not to correlate with disc displacement. The degree of disc displacement before treatment did not correlate with the post-surgical mandibular positional change in either the sagittal or vertical direction. To conclude, the mandibular bilateral sagittal split ramus osteotomy was stable in the long-term after orthognathic and orthodontic treatment. In the absence of pre-treatment condylar resorption, the degree of initial anterior disc displacement did not have a significant influence on the stability of mandibular advancement.
Solid–solid reaction, particularly in the Fe–O binary system, has been extensively studied in the past decades because of its various applications in chemistry and materials and earth sciences. The ...recently synthesized pyrite-FeO2 at high pressure suggested a novel oxygen-rich stoichiometry that extends the achievable O–Fe ratio in iron oxides by 33%. Although FeO2 was synthesized from Fe2O3 and O2, the underlying solid reaction mechanism remains unclear. Herein, combining in situ X-ray diffraction experiments and first-principles calculations, we identified that two competing phase transitions starting from Fe2O3: (1) without O2, perovskite-Fe2O3 transits to the post-perovskite structure above 50 GPa; (2) if free oxygen is present, O diffuses into the perovskite-type lattice of Fe2O3 leading to the pyrite-type FeO2 phase. We found the O–O bonds in FeO2 are formed by the insertion of oxygen into the Pv lattice via the external stress and such O–O bonding is only kinetically stable under high pressure. This may provide a general mechanism of adding extra oxygen to previous known O saturated oxides to produce unconventional stoichiometries. Our results also shed light on how O is enriched in mantle minerals under pressure.
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