An Examination of the Predictability of Tropical Cyclone Genesis in High-Resolution Coupled Models with Dynamically Downscaled Coupled Data Assimilation Initialization

Predicting tropical cyclone(TC)genesis is of great societal importance but scientifically challenging.It requires fineresolution coupled models that properly represent air−sea interactions in the atmospheric responses to local warm sea surface temperatures and feedbacks,with aid from coherent coupled initialization.This study uses three sets of highresolution regional coupled models(RCMs)covering the Asia−Pacific(AP)region initialized with local observations and dynamically downscaled coupled data assimilation to evaluate the predictability of TC genesis in the West Pacific.The APRCMs consist of three sets of high-resolution configurations of the Weather Research and Forecasting−Regional Ocean Model System(WRF-ROMS):27-km WRF with 9-km ROMS,and 9-km WRF with 3-km ROMS.In this study,a 9-km WRF with 9-km ROMS coupled model system is also used in a case test for the predictability of TC genesis.Since the local sea surface temperatures and wind shear conditions that favor TC formation are better resolved,the enhanced-resolution coupled model tends to improve the predictability of TC genesis,which could be further improved by improving planetary boundary layer physics,thus resolving better air−sea and air−land interactions.

Wnt3a-induced ST2 decellularized matrix ornamented PCL scaffold for bone tissue engineering

The limited bioactivity of scaffold materials is an important factor that restricts the development of bone tissue engineering.Wnt3a activates the classicWnt/β-catenin signaling pathway which effects bone growth and development by the accumulation ofβ-catenin in the nucleus.In this study,we fabricated 3D printed PCL scaffold with Wnt3a-induced murine bone marrow-derived stromal cell line ST2 decellularized matrix(Wnt3a-ST2-dCM-PCL)and ST2 decellularized matrix(ST2-dCM-PCL)by freeze-thaw cycle and DNase decellularization treatment which efficiently decellularized>90%DNA while preserved most protein.Compared to ST2-dCM-PCL,Wnt3a-ST2-dCM-PCL significantly enhanced newly-seeded ST2 proliferation,osteogenic differentiation and upregulated osteogenic marker genes alkaline phosphatase(Alp),Runx2,type I collagen(Col 1)and osteocalcin(Ocn)mRNA expression.After 14 days of osteogenic induction,Wnt3a-ST2-dCM-PCL promoted ST2 mineralization.These results demonstrated that Wnt3a-induced ST2 decellularized matrix improve scaffold materials’osteoinductivity and osteoconductivity.

A novel decellularized matrix of Wnt signaling-activated osteocytes accelerates the repair of critical-sized parietal bone defects with osteoclastogenesis, angiogenesis, and neurogenesis

Cell source is the key to decellularized matrix(DM)strategy.This study compared 3 cell types,osteocytes with/without dominant active Wnt/β-catenin signaling(daCO and WTO)and bone marrow stromal cells(BMSCs)for their DMs in bone repair.Decellularization removes all organelles and>95%DNA,and retained>74%collagen and>71%GAG,maintains the integrity of cell basement membrane with dense boundaries showing oval and honeycomb structure in osteocytic DM and smooth but irregular shape in the BMSC-DM.DM produced higher cell survival rate(90%)and higher proliferative activity.In vitro,daCO-DM induces more and longer stress fibers in BMSCs,conducive to cell adhesion,spreading,and osteogenic differentiation.8-wk after implantation of the critical-sized parietal bone defect model,daCO-DM formed tight structures,composed of a large number of densely-arranged type-I collagen under polarized light microscope,which is similar to and integrated with host bone.BV/TV(>54%)was 1.5,2.9,and 3.5 times of WTO-DM,BMSC-DM,and none-DM groups,and N.Ob/T.Ar(3.2×10^(2)/mm^(2))was 1.7,2.9,and 3.3 times.At 4-wk,daCO-DM induced osteoclastogenesis,2.3 times higher than WTO-DM;but BMSC-DM or none-DM didn't.daCO-DM increased the expression of RANKL and MCSF,Vegfa and Angpt1,and Ngf in BMSCs,which contributes to osteoclastogenesis,angiogenesis,and neurogenesis,respectively.daCO-DM promoted H-type vessel formation and nerve markersβ3-tubulin and NeuN expression.Conclusion:daCO-DM produces metabolic and neurovascularized organoid bone to accelerate the repair of bone defects.These features are expected to achieve the effect of autologous bone transplantation,suitable for transformation application.

Dissolved metal ion removal by online hollow fiber ultrafiltration for enhanced size characterization of metal-containing nanoparticles with single-particle ICP-MS

Single particle-inductively coupled plasma mass spectrometry (SP-ICP-MS) is a powerful tool for size-characterization of metal-containing nanoparticles (MCNs) at environmentally relevant concentrations,however,coexisting dissolved metal ions greatly interfere with the accuracy of particle size analysis.The purpose of this study is to develop an online technique that couples hollow fiber ultrafiltration (HFUF) with SP-ICP-MS to improve the accuracy and size detection limit of MCNs by removing metal ions from suspensions of MCNs.Through systematic optimization of conditions including the type and concentration of surfactant and complexing agent,carrier pH,and ion cleaning time,HFUF completely removes metal ions but retains the MCNs in suspension.The optimal conditions include using a mixture of 0.05 vol.%FL-70 and 0.5 mmol/L Na2S2O_(3)(pH=8.0) as the carrier and 4 min as the ion cleaning time.At these conditions,HFUF-SP-ICP-MS accurately determines the sizes of MCNs,and the results agree with the size distribution determined by transmission electron microscopy,even when metal ions also are present in the sample.In addition,reducing the ionic background through HFUF also lowers the particle size detection limit with SP-ICP-MS (e.g.,from 28.3 to 14.2 nm for gold nanoparticles).This size-based ion-removal principle provided by HFUF is suitable for both cations (e.g.,Ag+) and anions (e.g.,AuCl_(4)^(-)) and thus has good versatility compared to ion exchange purification and promising prospects for the removal of salts and macromolecules before single particle analysis.

Porcine Bocavirus: A 10-Year History since Its Discovery

Porcine bocavirus(PBoV)is a single-stranded DNA virus,belongs to the genus Bocaparvovirus of family Parvoviridae.It was discovered along with porcine circovirus 2(PCV 2)and torque tenovirus(TTV)in the lymph nodes of pigs suffering from postweaning multisystemic wasting syndrome(PMWS)in Sweden in 2009.PBoV has been reported throughout the world,mostly in weaning piglets,and has a broad range of tissue tropism.Since PBoV is prevalent in healthy as well as clinically infected pigs and is mostly associated with coinfection with other viruses,the pathogenic nature of PBoV is still unclear.Currently,there are no cell lines available for the study of PBoV,and animal model experiments have not been described.This review summarizes the current state of knowledge about PBoV,including the epidemiology,evolution analysis,detection methods,pathogenesis and public health concerns.

A high-resolution Asia-Pacific regional coupled prediction system with dynamically downscaling coupled data assimilation

A regional coupled prediction system for the Asia-Pacific(AP-RCP)(38°E-180°,20°S-60°N) area has been established.The AP-RCP system consists of WRF-ROMS(Weather Research and Forecast,and Regional Ocean Model System) coupled models combined with local observational information through dynamically downscaling coupled data assimilation(CDA).The system generates 18-day forecasts for the atmosphere and ocean environment on a daily quasi-operational schedule at Pilot National Laboratory for Marine Science and Technology(Qingdao)(QNLM),consisting of 2 different-resolution coupled models:27 km WRF coupled with 9 km ROMS,9 km WRF coupled with 3 km ROMS,while a version of 3 km WRF coupled with 3 km ROMS is in a test mode.This study is a first step to evaluate the impact of high-resolution coupled model with dynamically downscaling CDA on the extended-range predictions,focusing on forecasts of typhoon onset,improved precipitation and typhoon intensity forecasts as well as simulation of the Kuroshio current variability associated with mesoscale oceanic activities.The results show that for realizing the extended-range predictability of atmospheric and oceanic environment characterized by statistics of mesoscale activities,a fine resolution coupled model resolving local mesoscale phenomena with balanced and coherent coupled initialization is a necessary first step.The next challenges include improving the planetary boundary physics and the representation of air-sea and air-land interactions to enable the model to resolve kilometer or sub-kilometer processes.

Hydroxyl radical formation upon dark oxidation of reduced iron minerals: Effects of iron species and environmental factors

Dark formation of hydroxyl radical upon oxidation of reduced iron minerals plays an important role in the degradation and transformation of organic and inorganic pollutants.Herein,we compared the hydroxyl radical formation from various reduced iron minerals at different redox conditions.·OH production was generally observed from the oxidation of reduced iron minerals,following the order:mackinawite(FeS)>reduced nontronite(iron-bearing smectite clay)> pyrite(FeS2)> side rite(FeCO3).Structural Fe^2+ and dissolved O2 play critical roles in ·OH production from reduced iron minerals.·OH production increases with decreasing pH,and Cl^-has little effect on this process.More importantly,dissolved organic matter significantly enhances ·OH production,especially under O2 purging,highlighting the importance of this process in ambient environments.This sunlight-independent pathway in which ’OH forms during oxidation of reduced iron minerals is helpful for understanding the degradation and transformation of various inorganic and organic pollutants in the redox-fluctuation environments.

Thiolated arsenicals in arsenic metabolism: Occurrence,formation, and biological implications

Arsenic（As） is a notoriously toxic pollutant of health concern worldwide with potential risk of cancer induction, but meanwhile it is used as medicines for the treatment of different conditions including hematological cancers. Arsenic can undergo extensive metabolism in biological systems, and both toxicological and therapeutic effects of arsenic compounds are closely related to their metabolism. Recent studies have identified methylated thioarsenicals as a new class of arsenic metabolites in biological systems after exposure of inorganic and organic arsenicals, including arsenite, dimethylarsinic acid（DMAV）, dimethylarsinous glutathione（DMAIIIGS）, and arsenosugars. The increasing detection of thiolated arsenicals,including monomethylmonothioarsonic acid（MMMTAV）, dimethylmonothioarsinic acid（DMMTAV） and its glutathione conjugate（DMMTAVGS）, and dimethyldithioarsinic acid（DMDTAV） suggests that thioarsenicals may be important metabolites and play important roles in arsenic toxicity and therapeutic effects. Here we summarized the reported occurrence of thioarsenicals in biological systems, the possible formation pathways of thioarsenicals, and their toxicity, and discussed the biological implications of thioarsenicals on arsenic metabolism, toxicity, and therapeutic effects.

Refining mercury emission estimations to the atmosphere from iron and steel production

Due to its long-range transport in the atmosphere,mercury is a pollutant of global concern with health risks to humans and ecosystems worldwide（Li et al.,2012;Lindqvist et al.,1991;Liu et al.,2012a;Tang et al.,2016;Wang et al.,2015;Shao et al.,2016）.Atmospheric mercury,mainly from emission from various natural and anthropogenic sources and re-emission of previously released mercury built up in surface soils and oceans,

Mercury transformation processes in nature: Critical knowledge gaps and perspectives for moving forward

The transformation of mercury(Hg) in the environment plays a vital role in the cycling of Hg and its risk to the ecosystem and human health. Of particular importance are Hg oxidation/reduction and methylation/demethylation processes driven or mediated by the dynamics of light, microorganisms, and organic carbon, among others. Advances in understanding those Hg transformation processes determine our capacity of projecting and mitigating Hg risk. Here, we provide a critical analysis of major knowledge gaps in our understanding of Hg transformation in nature, with perspectives on approaches moving forward. Our analysis focuses on Hg transformation processes in the environment, as well as emerging methodology in exploring these processes. Future avenues for improving the understanding of Hg transformation processes to protect ecosystem and human health are also explored.

Dissolved organic matter-mediated reduction of ionic Au(Ⅲ)to elemental Au nanoparticles and their growth to visible granules

The biogeochemical transformation of gold(Au),i.e.its dissolution and re-precipitation,is critical in supergene transport of Au and formation of Au granules.Besides biogenic reduction,the formation Au granules can also be driven by chemical processes.Previous studies have showed the fo rmation of Au nanoparticles(AuNPs)from ionic Au(Ⅲ)can be mediated by dissolved organic matter under sunlight.In this letter,we further demonstrated that these AuNPs can further slowly(in years)grow into visible Au granules.Different sized nano-flower and fractal dendrite-like branched gold structures(from tens of nanometres to over 100μm)were observed in the Au granule sample.This growth of AuNPs into visible Au granules may play a critical role in the supergene mineralization and enrichment of secondary Au and drive the biogeochemical cycle of Au.