Differences of polygonal faults related to upper Miocene channels:a case study from the Beijiao sag of Qiongdongnan basin,South China Sea

Deep-water coarse-grained channels are embedded within a polygonal fault tier,and the polygonal faults(PFs)present non-polygonal geometries rather than classic polygonal geometry in plan view.However,PFs present differences when they encounter deep-water(coarse-grained vs.fine-grained)channels with different lithology,which has not been further studied to date.Three-dimensional(3D)seismic data and a drilling well from Beijiao sag of Qiongdongnanbasin,South China Sea were utilized to document the plan view and cross-sectional properties of the PFs and their differences and genetic mechanism were investigated.Results show that,first,PFs can be divided morphologically into channel-segmenting PFs and channel-bounding PFs in plan view.The former virtually cuts or segments the axes of channels in highand low-amplitudes,and the latter nearly parallels the boundaries of the channels.Both are approximately perpendicular to each other.Secondly,channel-bounding PFs that related to low-amplitude channels are much longer than those of high-amplitude ones;channel-segmenting PFs related to low-amplitude channels are slightly longer than the counterparts related to high-amplitude channels.Lastly,the magnitudes(e.g.,heights)of the PFs are proportional to the scales(e.g.,widths and heights)of low-amplitude channels,whereas the magnitudes of the PFs are inversely proportional to the scales of high amplitude channels.Coarse-grained(high amplitude)channels act as a mechanical barrier to the propagation of PFs,whereas fine-grained(low-amplitude)channels are beneficial to the propagation and nucleation of PFs.Additionally,the genetic mechanism of PFs is discussed and reckoned as combined geneses of gravitational spreading and overpressure hydrofracture.The differences of the PFs can be used to reasonably differentiate coarse-grained channels from fine-grained channels.This study provides new insights into understanding the different geometries of the PFs related to coarse-grained and fine-grained channels and their genetic mechanism.

Observation of spin-glass behavior in 1111-type magnetic semiconductor(La,Ba)(Zn,Mn)SbO

We report the successful fabrication of a new 1111-type bulk magnetic semiconductor(La,Ba)(Zn,Mn)SbO through the solid solution of(La,Ba)and(Zn,Mn)in the parent compound LaZnSbO.The polycrystalline samples(La,Ba)(Zn,Mn)SbO crystallize into ZrCuSiAs-type tetragonal structure,which has the same structure as iron-based superconductor LaFeAsO_(1-δ).The DC magnetization measurements indicate the existence of spin-glass ordering,and the coercive field is up to~11500 Oe(1 Oe=79.5775 A·m^(-1)).The AC magnetic susceptibility further determines that the samples evolve into a conventional spin-glass ordering state below the spin freezing temperature T_(f).In addition,the negative magnetoresistance(MR≡[ρ(H)-ρ(0)]/ρ(0))reaches-88%under 9 T.

(Ba_(1−x)Na_(x))F(Zn_(1−x)Mn_(x))Sb: A novel fluoride-antimonide magnetic semiconductor with decoupled charge and spin doping

We report the successful synthesis and characterization of a novel 1111-type magnetic semiconductor(Ba_(1−x)Na_(x))F(Zn_(1−x)Mn_(x))Sb(0.05≤x≤0.175)with tetragonal ZrSiCuAs-type structure,which is isostructural to the layered iron-based superconductor La(O,F)FeAs.Na substitutions for Ba and Mn substitutions for Zn introduce carriers and local magnetic moments,respectively.Ferromagnetic interaction is formed when Na and Mn are codoped,demonstrating that local magnetic moments are mediated by carriers.Iso-thermal magnetization shows that the coercive field is as large as-12000 Oe,which is also reflected in the large split between the temperature-dependent magnetization in zero-field-cooling and field-cooling condition.AC susceptibility under zero field demonstrates that samples evolve into spin-glass state below spin freezing temperature T_(f).The measurements of temperature-dependent resistivity indicate that(Ba_(1−x)Na_(x))F(Zn_(1−x)Mn_(x))Sb exhibits semiconducting behaviour.

Characteristics and origins of middle Miocene mounds and channels in the northern South China Sea

Numerous elongated mounds and channels were found at the top of the middle Miocene strata using 2D/3D seismic data in the Liwan Sag of Zhujiang River Mouth Basin(ZRMB)and the Beijiao Sag of Qiongdongnan Basin(QDNB).They occur at intervals and are rarely revealed by drilling wells in the deepwater areas.Origins of the mounds and channels are controversial and poorly understood.Based on an integrated analysis of the seismic attribute,palaeotectonics and palaeogeography,and drilling well encountering a mound,research results show that these mounds are dominantly distributed on the depression centres and/or slopes of the Liwan and Beijiao sags and developed in a bathyal sedimentary environment.In the Liwan and Beijiao sags,the mounds between channels(sub)parallel to one another are 1.0–1.5 km and 1.5–2.0 km wide,150–300 m and 150–200 m high,and extend straightly from west to east for 5–15 km and 8–20 km,respectively.Mounds and channels in the Liwan Sag are parallel with the regional slope.Mounds and channels in the Beijiao Sag,however,are at a small angle to the regional slope.According to internal geometry,texture and external morphology of mounds,the mounds in Beijiao Sag are divided into weak amplitude parallel reflections(mound type I),blank or chaotic reflections(mound type II),and internal mounded reflections(mound typeⅢ).The mounds in Liwan Sag,however,have the sole type,i.e.,mound type I.Mound type I originates from the incision of bottom currents and/or gravity flows.Mound type II results from gravity-driven sediments such as turbidite.Mound typeⅢis a result of deposition and incision of bottom currents simultaneously.The channels with high amplitude between mounds in the Beijiao and Liwan sags are a result of gravity-flow sediments and it is suggested they are filled by sandstone.Whereas channels with low-mediate amplitudes are filled by bottom-current sediments only in the Beijiao Sag,where they are dominantly composed of mudstone.This study provides new insights into the origins of the mounds and channels worldwide.

(Ca,K)(Zn,Mn)_(2)As_(2):Ferromagnetic semiconductor induced by decoupled charge and spin doping in CaZn_(2)As_(2)

We have successfully synthesized a novel diluted magnetic semiconductor(Ca_(1−2x)K_(2x))(Zn_(1−x)Mn_(x))_(2)As_(2) with decoupled charge and spin doping.The substitutions of(Ca^(2+),K^(+))and(Zn^(2+),Mn^(2+))in the parent compound CaZn_(2)As_(2)(space group P m1(No.164))introduce carriers and magnetic moments,respectively.Doping only Mn into CaZn_(2)As_(2) does not induce any type of long range magnetic ordering.The ferromagnetic ordering arise can only when K^(+)and Mn^(2+)are simultaneously doped.The res-ulted maximum Curie temperature reaches~7 K,and the corresponding coercive field is~60 Oe.The transport measurements confirm that samples with K and Mn co-doping still behave like a semiconductor.

G protein-coupled receptor 35 attenuates nonalcoholic steatohepatitis by reprogramming cholesterol homeostasis in hepatocytes

Nonalcoholic fatty liver disease(NAFLD)is the most common chronic liver disease worldwide.Fat accumulation“sensitizes”the liver to insult and leads to nonalcoholic steatohepatitis(NASH).G protein-coupled receptor 35(GPR35)is involved in metabolic stresses,but its role in NAFLD is unknown.We report that hepatocyte GPR35 mitigates NASH by regulating hepatic cholesterol homeostasis.Specifically,we found that GPR35 overexpression in hepatocytes protected against high-fat/cholesterol/fructose(HFCF)diet-induced steatohepatitis,whereas loss of GPR35 had the opposite effect.Administration of the GPR35 agonist kynurenic acid(Kyna)suppressed HFCF diet-induced steatohepatitis in mice.Kyna/GPR35 induced expression of StAR-related lipid transfer protein 4(STARD4)through the ERK1/2 signaling pathway,ultimately resulting in hepatic cholesterol esterification and bile acid synthesis(BAS).The overexpression of STARD4 increased the expression of the BAS rate-limiting enzymes cytochrome P450 family 7 subfamily A member 1(CYP7A1)and CYP8B1,promoting the conversion of cholesterol to bile acid.The protective effect induced by GPR35 overexpression in hepatocytes disappeared in hepatocyte STARD4-knockdown mice.STARD4 overexpression in hepatocytes reversed the aggravation of HFCF diet-induced steatohepatitis caused by the loss of GPR35 expression in hepatocytes in mice.Our findings indicate that the GPR35–STARD4 axis is a promising therapeutic target for NAFLD.

Indocyanine green-/TLR7 agonist-constructed thermosensitive liposome for low-temperature PTT induced synergistic immunotherapy of colorectal cancer

Colorectal cancer(CRC)is a lethal malignancy with a high mortality rate due to its low immunogenicity,the strong immunosuppressive milieu and poor drug permeability.To overcome these obstacles,a cascade synergistic nanosystem(denoted as R837/ICG@Lip)was developed via self-assembly of heater indocyanine green(ICG)and toll-like receptor-7 agonist imiquimod(R837)into thermosensitive liposome for simultaneous induction of immunogenic cell death(ICD)and reversing of suppressive tumor microenvironment.The obtained nanoparticles exhibited NIR-triggered drug release,good photothermal conversion efficiency and phototoxicity towards CT26 colorectal cancer cells.In vivo results reveal that the R837/ICG@Lip could be effectively accumulated in CT26 subcutaneous tumors and the draining lymph nodes.More importantly,R837/ICG@Lip-mediated low-temperature photothermal therapy triggers ICD,promotes the maturation of host dendritic cells(DCs),and subsequently amplifies adaptive antitumor T-cell responses,resulting in‘Cold to Hot'transition.Besides directly affecting immune cells,the secretion of some immune-related cytokines further indirectly boosted anti-cancer immunity.After combining with the indoleamine 2,3-dioxygenase(IDO)inhibitor,the systemic antitumor immune response was further augmented,achieving best tumor inhibition effects.Thus,low-temperature mediated photoimmunotherapy targeting multiple antitumor immune pathways boost synergistic antitumor immunity of tolerance tumors.

Hypoxia-mimicking 3D bioglass-nanoclay scaffolds promote endogenous bone regeneration

Large bone defect repair requires biomaterials that promote angiogenesis and osteogenesis.In present work,a nanoclay(Laponite,XLS)-functionalized 3D bioglass(BG)scaffold with hypoxia mimicking property was prepared by foam replication coupled with UV photopolymerization methods.Our data revealed that the incorporation of XLS can significantly promote the mechanical property of the scaffold and the osteogenic differentiation of human adipose mesenchymal stem cells(ADSCs)compared to the properties of the neat BG scaffold.Desferoxamine,a hypoxia mimicking agent,encourages bone regeneration via activating hypoxia-inducible factor-1 alpha(HIF-1α)-mediated angiogenesis.GelMA-DFO immobilization onto BG-XLS scaffold achieved sustained DFO release and inhibited DFO degradation.Furthermore,in vitro data demonstrated increased HIF-1αand vascular endothelial growth factor(VEGF)expressions on human adipose mesenchymal stem cells(ADSCs).Moreover,BG-XLS/GelMA-DFO scaffolds also significantly promoted the osteogenic differentiation of ADSCs.Most importantly,our in vivo data indicated BG-XLS/GelMA-DFO scaffolds strongly increased bone healing in a critical-sized mouse cranial bone defect model.Therefore,we developed a novel BG-XLS/GelMA-DFO scaffold which can not only induce the expression of VEGF,but also promote osteogenic differentiation of ADSCs to promote endogenous bone regeneration.