Greigite as an indicator for salinity and sedimentation rate change : evidence from the Yangtze River delta, China

Ferrimagnetic greigite (Fe3S4) is widespread in the sedimentary environment. Despite abundant reports of greigite occurrence in marine and lacustrine deposits, its formation mechanisms in deltaic deposits remain poorly studied. Here we investigate greigite in Holocene Yangtze River delta deposits using granulometric, magnetic and geochemical methods. The studied cores consist of tidal river, estuary, shallow marine and delta facies in ascending order. The greigite‐bearing layers are found predominantly in the accreting tidal flat facies during the transgression stage and secondarily in the shallow marine facies during the regression stage of the delta's Holocene development. These sedimentary intervals have a higher total sulfur (TS) content and total sulfur to total organic carbon ratios (TS/TOC) suggesting the accumulation of iron sulfides, including greigite, under reducing estuarine and shallow marine conditions. The greigite‐bearing layers in the tidal flat facies have lower Sr/Ba ratios, in comparison to the shallow marine facies, indicating a lower salinity environment. Supported by the dating results, it is suggested that the higher sedimentation rate of the tidal flat facies, caused by rapid sea‐level rise during the early Holocene, favors the formation and preservation of greigite. Our results indicate that the magnetic detection of greigite provides a simple and useful tool for inferring salinity and sedimentation rate changes, and hence better a understanding of the heterogeneity of depositional processes in Holocene delta environments

The effect of boron addition on the atomic structure and microwave magnetic properties of FeGaB thin films

Varying amounts of boron were added to the host FeGa alloy to investigate its impact upon local atomic structure and magnetic and microwave properties. The impact of B upon the local atomic structure in FeGaB films was investigated by extended x-ray absorption fine structure ͑EXAFS͒ analysis. The EXAFS fitting results revealed a contraction of lattice parameters with the introduction of B. The Debye-Waller factor determined from EXAFS fitting increases as a function of boron addition and abruptly changes during the structural evolution from crystalline to amorphous that occurs near 9% B. Upon the onset of this transition the static and microwave magnetic properties became exceptionally soft, with values of coercivity and ferromagnetic linewidth reducing to less than 1 Oe and 25 Oe, respectively

Challenges and Opportunities for Multi-functional Oxide Thin Films for Voltage Tunable Radio Frequency/Microwave Components

There has been significant progress on the fundamental science and technological applications of complex oxides and multiferroics. Among complex oxide thin films, barium strontium titanate (BST) has become the material of choice for room-temperature-based voltage-tunable dielectric thin films, due to its large dielectric tunability and low microwave loss at room temperature. BST thin film varactor technology based reconfigurable radio frequency (RF)/microwave components have been demonstrated with the potential to lower the size, weight, and power needs of a future generation of communication and radar systems. Low-power multiferroic devices have also been recently demonstrated. Strong magneto-electric coupling has also been demonstrated in different multiferroic heterostructures, which show giant voltage control of the ferromagnetic resonance frequency of more than two octaves. This manuscript reviews recent advances in the processing, and application development for the complex oxides and multiferroics, with the focus on voltage tunable RF/microwave components. The over-arching goal of this review is to provide a synopsis of the current state-of the-art of complex oxide and multiferroic thin film materials and devices, identify technical issues and technical challenges that need to be overcome for successful insertion of the technology for both military and commercial applications, and provide mitigation strategies to address these technical challenges

CXCL6 Promotes Renal Interstitial Fibrosis in Diabetic Nephropathy by Activating JAK/STAT3 Signaling Pathway

In this study the role of CXCL6 in diabetic nephropathy (DN) was investigated. It was found to be overexpression in DN patients and DN rat model. And the expression of fibrosis-related cytokines was consistent with the expression of CXCL6. High glucose significantly increased the proliferation of rat renal fibroblasts NRK-49F cell and the expression of CXCL6. Knockdown of CXCL6 ameliorated the pro-proliferation effect of high glucose and decreased the expression of fibrosis-related cytokines, while CXCL6 overexpression exhibited the opposite phenomenon. Gene set enrichment analysis, Western blot and ELISA showed that Janus kinase-signal transducer and activator of transcription (JAK-STAT) and CYTOKINE_CYTOKINE_RECEPTOR_INTERACTION signaling pathways were correlative with CXCL6. This data indicates that CXCL6 may promote fibrosis-related factors to accelerate the development of DN renal interstitial fibrosis by activating JAK/STAT3 signaling pathway. CXCL6 is promising to be a potential novel therapeutic target and candidate biomarker for JAK/STAT3 signaling for the treatment of DN