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Seismic anisotropy in the upper mantle beneath East Asia has been studied extensively using shear wave (SKS) splitting measurements, which have provided important information on mantle dynamics in this region. However, SKS measurements have poor vertical resolution, and so their interpretations are usually not unique. In this work we use a large number of traveltime data from 34,036 local earthquakes recorded by 1563 seismic stations to determine the first model of 3-D P wave azimuthal anisotropy in the lithosphere beneath China. Our results show that the fast velocity directions (FVDs) are generally correlated with the surface geologic features, such as the strikes of the orogens, active faults, and tectonic boundaries. The FVDs in the upper crust are normal to the maximal horizontal stress (σ H ) in regions with extensive compression such as the Tibetan Plateau, whereas they are subparallel to σ H in strike-slip shear zones such as the western and eastern Himalayan syntax. The comparison of the FVDs of P wave anisotropy with SKS splitting measurements indicates that beneath the Tibetan Plateau the seismic anisotropy in the lithosphere contributes significantly to the SKS splitting observations. In contrast, in east China the P wave FVDs in the lithosphere are different from the SKS splitting measurements, suggesting that the SKS splitting is mainly caused by the anisotropy in the deeper mantle such as the asthenosphere and the mantle transition zone under east China. These novel results provide important new information on the lithospheric deformation and mantle dynamics in East Asia.

The subduction of the Indian Plate beneath SE Tibet and its related volcanism in Tengchong are important geologic processes that accompany the evolution of the Tibetan Plateau. However, it is still not clear whether the subduction and volcanism are confined to the upper mantle or if they extend deep into the mantle transition zone (MTZ). Here, we imaged MTZ structures by using receiver function methods with the waveforms recorded by more than 300 temporary stations in SE Tibet. The results show significant depressions of both the 410-km and 660-km discontinuities and a thickened MTZ (260-280 km) beneath SE Tibet. The depression of the 660-km discontinuity (by 10-30 km) and the thickened MTZ correlate well with high P-wave velocity anomalies in the MTZ, indicating the presence of a subducted Indian slab within the MTZ. Significant depression of the 410-km discontinuity (by 10-20 km) beneath the Tengchong volcano indicates that the volcano originates from the MTZ and is closely related to the subducted Indian slab. Our results confirm the deep subduction of the Indian plate and the deep origin of the Tengchong volcano.However, it remains unknown whether a slab gap exists and contributes to the Tengchong volcano.

We applied the gCAP algorithm to determine 239 focal mechanism solutions 3:0 M W 6:0 ð Þwith records of dense ChinArray stations deployed in Yunnan, and then inverted 686 focal mechanisms (including 447 previous results) for the regional crustal stress field with a damped linear inversion. The results indicate dominantly strike-slip environment in Yunnan as both the maximum (r 1 ) and minimum (r 3 ) principal stress axes are sub-horizontal. We further calculated the horizontal stress orientations (i.e., maximum and minimum horizontal compressive stress axes: S H and S h , respectively) accordingly and found an abrupt change near *26°N. To the north, S H aligns NW-SE to nearly E-W while S h aligns nearly N-S. In contrast, to the south, both S H and S h rotate laterally and show dominantly fan-shaped patterns. The minimum horizontal stress (i.e., maximum strain axis) S h rotates from NW-SE to the west of Tengchong volcano gradually to nearly E-W in west Yunnan, and further to NE-SW in the South China block in the east. The crustal strain field is consistent with the upper mantle strain field indicated by shear-wave splitting observations in Yunnan but not in other regions. Therefore, the crust and upper mantle in Yunnan are coupled and suffering vertically coherent pure-shear deformation in the lithosphere.

[1] Recently, many portable broadband three-component seismic stations have been deployed in Yunnan, China. We use teleseismic receiver functions to determine the crustal thickness (H) and the crustal average compressional to shear wave velocity (V p /V s ) ratio (k) variations beneath in southwest Yunnan. By comparing the synthetics generated from dipping Moho models with those from a flat Moho model, it reveals that for the rays traveling along or around the updip direction, the differential arrival times of Ps and multiples generated at the dipping Moho are comparable with those generated at the flat Moho and the result from stacking with these synthetics is a better estimate of model structure. For the synthetics traveling along or around the downdip direction, the differential arrival times of Ps and multiples generated at dipping Moho are smaller than those generated at flat Moho and make the H-k stacking results deviate from the model structure. Thus, the ambiguity induced by dipping Moho can be reduced significantly by only stacking with the rays traveling along or around the updip direction. Applying this technique to 19 stations, we obtained that H ranges from ∼35-42 km and the k ranges from ∼1.66-1.78. From the central Simao basin, H increases northward and northeastward; k increases significantly northeastward across the Ailao Shan-Red River shear zone.

[1] A dense seismic array consisting of 28 temporary stations was deployed to study the crustal and upper-mantle deformations beneath eastern China. We measured the splitting parameters in the crust and mantle by analyzing P-to-S phases converted at the Moho discontinuity (called PmS phases) and the core-mantle boundary (i.e., core phases), respectively. The splitting parameters of core phases are retrieved at most stations while that of the PmS phases are retrieved at only a few stations. Distinct lateral variations of the fast polarization directions analyzed with the core phases are found in different tectonic blocks in eastern China. The delay times in the mantle and crust are moderately large (~1 s) and averagely smaller than 0.3 s, respectively. By the Fresnel-zone analysis, the laterally variant lithospheric anisotropy is revealed between the two sub-blocks (Southeast China Orogenic Belt and Yangtze Craton) of the eastern South China Block. In contrast, in the southeastern North China Craton, the anisotropy in a relatively deep layer contributes to the splitting observations.

The aim of this study was to explore the role of galectin-3 in human epidermal growth factor receptor 2 (HER2)-positive breast cancer cells and the potential mechanism. Methods: Kaplan-Meier (KM)-plot and The Cancer Genome Atlas (TCGA) databases were used to study the role of galectin-3 in the prognosis of HER2-positive breast cancer. The effects of galectin-3 on cell proliferation, migration, invasion, and colony formation ability in HER2-positive breast cancer cells were examined. The relationship between galectin-3 and important components in the HER2 pathways, including HER2, epidermal growth factor receptor (EGFR), protein kinase B (AKT), and phosphatase and tensin homolog (PTEN), was further studied. Lentivirus and CRISPR/ Cas9 were used to construct stable cell lines. Cell counting kit-8 (CCK-8) and apoptosis assays were used to study the relationship between galectin-3 and trastuzumab. The effect of galectin-3 on cell stemness was studied by mammosphere formation assay. The effects of galectin-3 on stemness biomarkers and the Notch1 pathway were examined. Tumorigenic models were used to evaluate the effects of galectin-3 on tumorigenesis and the therapeutic effect of trastuzumab in vivo. Results: HER2-positive breast cancer patients with a high expression level of LGALS3 (the gene encoding galectin-3) messenger RNA (mRNA) showed a poor prognosis. Galectin-3 promoted cancer malignancy through phosphoinositide 3-kinase (PI3K)/ AKT signaling pathway activation and upregulated stemness by activating the Notch1 signaling pathway in HER2-positive breast cancer cells. These two factors contributed to the enhancement of trastuzumab resistance in cells. Knockout of LGALS3 had a synergistic therapeutic effect with trastuzumab both in vitro and in vivo. Conclusions: Galectin-3 may represent a prognostic predictor and therapeutic target for HER2-positive breast cancer.