Metal/metalloid and phosphorus characteristics in porewater associated with manganese geochemistry: A case study in the Jiulong River Estuary, China

Abstract(#br)Sediment porewater can be an important source of contaminants in the overlying water, but the mechanisms of metal(loid) and phosphorus (P) remobilization remain to be investigated. In this study, high-resolution dialysis (HR-Peeper) and diffusive gradients in thin films (DGT) samplers were used to determine the porewater dissolved iron (Fe), manganese (Mn), cobalt (Co), chromium (Cr), vanadium (V), selenium (Se), arsenic (As), P and DGT-Labile S in coastal sediments in the Jiulong River Estuary (JRE), China. The results showed that high concentrations of dissolved Mn, Se and P were present in the overlying water, indicating potential water pollution with excessive amounts of Mn, Se and P. The dissolved Mn concentrations in the porewater were higher than the dissolved Fe concentrations, especially at submerged sites, demonstrating that Mn(III/IV) reduction is the dominant diagenetic pathway for organic carbon (OC) degradation, which directly affects Fe cycling by the competitive inhibition of Fe(III) reduction and Fe(II) reoxidation. Dissolved Co, Cr, V, Se, As and P show significant positive correlations with Mn but nearly no correlations with Fe, suggesting that the mobility of these metal(loid)s and P is associated with Mn but not Fe cycling in this region. In addition, the coelevated concentrations of the metal(loid)s, P and Mn at the submerged sites are attributed to the strengthened Mn reduction coupled with OC degradation fueled by hypoxia. The higher positive diffusion fluxes of Mn, Se and P were consistent with the excess Mn, Se and P concentrations in the overlying water, together with the approximately positive fluxes of the other metal(loid)s, indicating that sediment Mn(III/IV) reduction and concomitant metal(loid) and P remobilization might be vital pathways for metal(loid) and P migration to the overlying water

Metal/metalloid and phosphorus characteristics in porewater associated with manganese geochemistry: A case study in the Jiulong River Estuary, China.

Sediment porewater can be an important source of contaminants in the overlying water, but the mechanisms of metal(loid) and phosphorus (P) remobilization remain to be investigated. In this study, high-resolution dialysis (HR-Peeper) and diffusive gradients in thin films (DGT) samplers were used to determine the porewater dissolved iron (Fe), manganese (Mn), cobalt (Co), chromium (Cr), vanadium (V), selenium (Se), arsenic (As), P and DGT-Labile S in coastal sediments in the Jiulong River Estuary (JRE), China. The results showed that high concentrations of dissolved Mn, Se and P were present in the overlying water, indicating potential water pollution with excessive amounts of Mn, Se and P. The dissolved Mn concentrations in the porewater were higher than the dissolved Fe concentrations, especially at submerged sites, demonstrating that Mn(III/IV) reduction is the dominant diagenetic pathway for organic carbon (OC) degradation, which directly affects Fe cycling by the competitive inhibition of Fe(III) reduction and Fe(II) reoxidation. Dissolved Co, Cr, V, Se, As and P show significant positive correlations with Mn but nearly no correlations with Fe, suggesting that the mobility of these metal(loid)s and P is associated with Mn but not Fe cycling in this region. In addition, the coelevated concentrations of the metal(loid)s, P and Mn at the submerged sites are attributed to the strengthened Mn reduction coupled with OC degradation fueled by hypoxia. The higher positive diffusion fluxes of Mn, Se and P were consistent with the excess Mn, Se and P concentrations in the overlying water, together with the approximately positive fluxes of the other metal(loid)s, indicating that sediment Mn(III/IV) reduction and concomitant metal(loid) and P remobilization might be vital pathways for metal(loid) and P migration to the overlying water

Rapamycin Enhances Mitophagy and Attenuates Apoptosis After Spinal Ischemia-Reperfusion Injury

The spinal cord is extremely vulnerable to ischemia-reperfusion (I/R) injury, and the mitochondrion is the most crucial interventional target. Rapamycin can promote autophagy and exert neuroprotective effects in several diseases of the central nervous system. However, the impact of rapamycin via modulating mitophagy and apoptosis after spinal cord ischemia-reperfusion injury remains unclear. This study was undertaken to investigate the potential role of rapamycin in modulating mitophagy and mitochondria-dependent apoptosis using the spinal cord ischemia-reperfusion injury (SCIRI) mouse model. We found that rapamycin significantly (p < 0.05) enhanced mitophagy by increasing the translocation of p62 and Parkin to the damaged mitochondria in the mouse spinal cord injury model. At the same time, rapamycin significantly (p < 0.05) decreased mitochondrial apoptosis related protein (Apaf-1, Caspase-3, Caspase-9) expression by inhibiting Bax translocation to the mitochondria and the release of the cytochrome c from the mitochondria. After 24 h following SCIRI, rapamycin treatment reduced the TUNEL+ cells in the spinal cord ischemic tissue and improved the locomotor function in these mice. Our results therefore demonstrate that rapamycin can improve the locomotor function by promoting mitophagy and attenuating SCIRI -induced apoptosis, indicating its potential therapeutic application in a spinal cord injury

Estimating submarine groundwater discharge in the Jiaozhou Bay using radium isotopes

1811-1819<span style="font-size:9.0pt;font-family: " times="" new="" roman";mso-fareast-font-family:simsun;mso-bidi-font-family:"times="" roman";="" mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:hi"="" lang="EN-GB">Submarine groundwater discharge (SGD) is part of the global water cycles, which delivers a large amount of solutes to the<span style="font-size:9.0pt; font-family:" times="" new="" roman";mso-fareast-font-family:simsun;mso-bidi-font-family:="" "times="" roman";mso-ansi-language:en-gb;mso-fareast-language:zh-cn;="" mso-bidi-language:hi"="" lang="EN-GB"> <span style="font-size:9.0pt; font-family:" times="" new="" roman";mso-fareast-font-family:simsun;mso-bidi-font-family:="" "times="" roman";mso-ansi-language:en-gb;mso-fareast-language:en-us;="" mso-bidi-language:hi"="" lang="EN-GB">biogeochemical cycle and affects the coastal ecological environment. Natural radium isotopes (224Ra and 226Ra) were used to estimate the SGD in Jiaozhou Bay and the mass balance models were established.  Radium sources including river transport, sediment diffusion, desorption from re-suspended particles, open sea flood tide, municipal wastewater, and SGD are considered. Radium<span style="font-size:9.0pt; font-family:" times="" new="" roman";mso-fareast-font-family:simsun;mso-bidi-font-family:="" "times="" roman";mso-ansi-language:en-gb;mso-fareast-language:zh-cn;="" mso-bidi-language:hi"="" lang="EN-GB"> <span style="font-size:9.0pt; font-family:" times="" new="" roman";mso-fareast-font-family:simsun;mso-bidi-font-family:="" "times="" roman";mso-ansi-language:en-gb;mso-fareast-language:en-us;="" mso-bidi-language:hi"="" lang="EN-GB">output owning to the radioactive decay and ebb tide are also considered. Our results show the<span style="font-size: 9.0pt;font-family:" times="" new="" roman";mso-fareast-font-family:simsun;mso-bidi-font-family:="" "times="" roman";mso-ansi-language:en-gb;mso-fareast-language:zh-cn;="" mso-bidi-language:hi"="" lang="EN-GB"> <span style="font-size:9.0pt; font-family:" times="" new="" roman";mso-fareast-font-family:simsun;mso-bidi-font-family:="" "times="" roman";mso-ansi-language:en-gb;mso-fareast-language:en-us;="" mso-bidi-language:hi"="" lang="EN-GB">SGD fluxes during September to October in 2011(autumn) and April to May in 2012 (spring)<span style="font-size:9.0pt; font-family:" times="" new="" roman";mso-fareast-font-family:simsun;mso-bidi-font-family:="" "times="" roman";mso-ansi-language:en-gb;mso-fareast-language:zh-cn;="" mso-bidi-language:hi"="" lang="EN-GB"> <span style="font-size:9.0pt; font-family:" times="" new="" roman";mso-fareast-font-family:simsun;mso-bidi-font-family:="" "times="" roman";mso-ansi-language:en-gb;mso-fareast-language:en-us;="" mso-bidi-language:hi"="" lang="EN-GB">are 15.17<span style="font-size:9.0pt; font-family:" times="" new="" roman";mso-fareast-font-family:simsun;mso-bidi-font-family:="" "times="" roman";mso-ansi-language:en-gb;mso-fareast-language:zh-cn;="" mso-bidi-language:hi"="" lang="EN-GB"> <span style="font-size:9.0pt; font-family:" times="" new="" roman";mso-fareast-font-family:simsun;mso-bidi-font-family:="" "times="" roman";mso-ansi-language:en-gb;mso-fareast-language:en-us;="" mso-bidi-language:hi"="" lang="EN-GB">and 6.53×106 m3·d-1, respectively. In the same period of time, the input of the dissolved inorganic nitrogen<span style="font-size:9.0pt;font-family: " times="" new="" roman";mso-fareast-font-family:simsun;mso-bidi-font-family:"times="" roman";="" mso-ansi-language:en-gb;mso-fareast-language:zh-cn;mso-bidi-language:hi"="" lang="EN-GB"> (DIN) from SGD is very close to that from river, yet, the soluble silicate and reactive phosphate vary seasonally. SGD is the major source of the nutrient input of Jiaozhou Bay.</span

Ca2+-supplying black phosphorus-based scaffolds fabricated with microfluidic technology for osteogenesis

Effective osteogenesis remains a challenge in the treatment of bone defects. The emergence of artificial bone scaffolds provides an attractive solution. In this work, a new biomineralization strategy is proposed to facilitate osteogenesis through sustaining supply of nutrients including phosphorus (P), calcium (Ca), and silicon (Si). We developed black phosphorus (BP)-based, three-dimensional nanocomposite fibrous scaffolds via microfluidic technology to provide a wealth of essential ions for bone defect treatment. The fibrous scaffolds were fabricated from 3D poly (l-lactic acid) (PLLA) nanofibers (3D NFs), BP nanosheets, and hydroxyapatite (HA)-porous SiO2 nanoparticles. The 3D BP@HA NFs possess three advantages: i) stably connected pores allow the easy entrance of bone marrow-derived mesenchymal stem cells (BMSCs) into the interior of the 3D fibrous scaffolds for bone repair and osteogenesis; ii) plentiful nutrients in the NFs strongly improve osteogenic differentiation in the bone repair area; iii) the photothermal effect of fibrous scaffolds promotes the release of elements necessary for bone formation, thus achieving accelerated osteogenesis. Both in vitro and in vivo results demonstrated that the 3D BP@HA NFs, with the assistance of NIR laser, exhibited good performance in promoting bone regeneration. Furthermore, microfluidic technology makes it possible to obtain high-quality 3D BP@HA NFs with low costs, rapid processing, high throughput and mass production, greatly improving the prospects for clinical application. This is also the first BP-based bone scaffold platform that can self-supply Ca2+, which may be the blessedness for older patients with bone defects or patients with damaged bones as a result of calcium loss

Celastrol-based nanomedicine hydrogels eliminate posterior capsule opacification - Supplementary table

Aim: To formulate an injectable thermosensitive micelle–hydrogel hybrid system loaded with celastrol (celastrol-loaded micelle hydrogel: CMG) to prevent posterior capsule opacification (PCO). Materials & methods: Celastrol-loaded micelles were embedded in a thermosensitive hydrogel matrix to enable controlled on-demand celastrol delivery into the residual capsule. The efficacy and mechanisms of the system for eliminating PCO were evaluated in rabbits. Results: Celastrol-loaded micelles inhibited the migration and proliferation of lens epithelial cells induced by TGF-β1. Celastrol prevents epithelial– mesenchymal transition in lens epithelial cells induced by TGF-β1 through the TGF-β1/Smad2/3/TEAD1 signaling pathway. In vivo efficiency evaluations showed that CMG demonstrated an excellent inhibitory effect on PCO in rabbits and had no obvious tissue toxicity. Conclusion: Injectable CMG may represent a promising ophthalmic platform for preventing PCO. This versatile injectable micelle–hydrogel hybrid represents a clinically relevant platform to achieve localized therapy and controlled release of drugs in other disease therapies.</p

M2 macrophages promote subconjunctival fibrosis through YAP/TAZ signalling

To evaluate the role of M2 macrophages in subconjunctival fibrosis after silicone implantation (SI) and investigate the underlying mechanisms. A model of subconjunctival fibrosis was established by SI surgery in rabbit eyes. M2 distribution and collagen deposition were evaluated by histopathology. The effects of M2 cells on the migration (using wound-scratch assay) and activation (by immunofluorescence and western blotting) of human Tenon’s fibroblasts (HTFs) were investigated. There were more M2 macrophages (CD68+/CD206+ cells) occurring in tissue samples around silicone implant at 2 weeks postoperatively. Dense collagen deposition was observed at 8 weeks after SI. In vitro experiment showed M2 expressed high level of CD206 and transforming growth factor-β1 (TGF-β1). The M2-conditioned medium promoted HTFs migration and the synthesis of collagen I and fibronectin. Meanwhile, M2-conditioned medium increased the protein levels of TGF-β1, TGF-βR II, p-Smad2/3, yes-associated protein (YAP), and transcriptional coactivator with PDZ-binding motif (TAZ). Verteporfin, a YAP inhibitor, suppressedTGF-β1/Smad2/3-YAP/TAZ pathway and attenuated M2-induced extracellular matrix deposition by HTFs. TGF-β1/Smad2/3-YAP/TAZ signalling may be involved in M2-induced fibrotic activities in HTFs. M2 plays a key role in promoting subconjunctival fibrosis and can serve as an attractive target for anti-fibrotic therapeutics.</p

Catalytic conversion of lignocellulosic biomass into chemicals and fuels

In the search of alternative resources to make commodity chemicals and transportation fuels for a low carbon future, lignocellulosic biomass with over 180-billion-ton annual production rate has been identified as a promising feedstock. This review focuses on the state-of-the-art catalytic transformation of lignocellulosic biomass into value-added chemicals and fuels. Following a brief introduction on the structure, major resources and pretreatment methods of lignocellulosic biomass, the catalytic conversion of three main components, i.e., cellulose, hemicellulose and lignin, into various compounds are comprehensively discussed. Either in separate steps or in one-pot, cellulose and hemicellulose are hydrolyzed into sugars and upgraded into oxygen-containing chemicals such as 5-HMF, furfural, polyols, and organic acids, or even nitrogen-containing chemicals such as amino acids. On the other hand, lignin is first depolymerized into phenols, catechols, guaiacols, aldehydes and ketones, and then further transformed into hydrocarbon fuels, bioplastic precursors and bioactive compounds. The review then introduces the transformations of whole biomass via catalytic gasification, catalytic pyrolysis, as well as emerging strategies. Finally, opportunities, challenges and prospective of woody biomass valorization are highlighted