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The specific topographic characteristics and complex hydrodynamics of seamounts could directly or indirectly affect the distribution and trophic status of microbes. However, little is known about the distribution patterns and associated driving forces of micro-eukaryotes in the deep seamounts. Micro-eukaryotes in the seamount sediments along the island arc of the Yap and Mariana trenches were investigated using high-throughput sequencing and quantitative PCR based on the 18S rRNA gene. Micro-eukaryotic communities from seamounts were clustered together and distinct from those of the depression, which showed comparatively lower diversity, gene abundance, endemic species, and higher proportions of decomposers and parasites. This clear geographical distribution pattern was mainly shaped by the deterministic process, especially environmental (61.63%) and biotic (mainly the unexplained 30.05%) factors, potentially reflecting the seamount effect along the horizontal dimension very likely caused by enclosed circulation cells. Varied community connectivity existed along the summit, flank, and base of different seamounts, and this seamount effect along the vertical dimension might be attributed to the upwelling/downwelling water flows. Prevalence of parasitism and predation for the trophic relationships among micro-eukaryotes would be helpful for adaptation, diversification, and maintaining the ecological balance in this extreme biosphere. This study provides insights into the ecological patterns, assembling processes, and species interactions underlying the dynamics of micro-eukaryotic communities across a series of seamounts with a comparison of the depression and would expand our understanding of seamount effects on the deep-sea ecosystems. © 2023 Zhang et al.

Serpentinization may provide a unique environment for the abiotic formation of condensed carbonaceous matter. This could support the deep biosphere and contribute to the deep carbon cycle, and may have provided the first building blocks for life. However, thus far, condensed carbonaceous matter has been found only in association with the minor mineral constituents of serpentinites. In contrast, here we show the direct association between carbonaceous matter and the dominant Fe oxide in serpentinites, magnetite. Our samples were recovered from the Yap Trench, western Pacific Ocean, with a human-occupied vehicle at a depth of 6413 m below sea level. The carbonaceous matter coincides with some micron-sized magnetite grains, but particularly with nanosized Fe oxides within serpentinite nanopores. Vibrational spectroscopy reveals that the condensed carbonaceous matter contains both aliphatic and aromatic compounds, but there is no evidence for functional groups typical for biological organics. Based on these observations, we suggest that physicochemical phenomena in serpentinite nanopores and nanosized catalytically active minerals may play a key role in the abiotic synthesis of complex carbonaceous matter.

Iodonium salts are the topic of interest in the field of photopolymerization as they act as effective photoinitiators and generators of photoacid. Yet, the current commercially available iodonium salts have low absorption above 300 nm whereby limiting the use of the long-wavelength of light irradiations to trigger polymerization. Iodonium salts are thus generally used in couples with photosensitizers (e.g., dyes) to extend the usage under irradiation of red-shifted light wavelength. In this research, the synthesis of chromophore-linked (anthraquinone-based and flavone-based chromophores) iodonium salts is present. They can initiate free radical polymerization with 320–480 nm irradiation and show much better photoinitiation ability as compared to commercial iodonium salts, especially when they act as mono-component photoinitiators. Steady-state photolysis and electron spin resonance spin trapping experiments are also carried out to evaluate the relevant photochemical mechanism.

Natural flavone-derivatives (i.e., morin and quercetin) are investigated as visible light-sensitive photoinitiators. The photochemical mechanisms of the radical generation from flavone-derivative-based photoinitiating systems (PISs) upon exposure to mild blue light-emitting diodes are studied. The impact of substituent site of functional groups on the photoinitiation ability is determined. The quercetin-based PISs exhibit more reactivity than the morin-based systems on free radical photopolymerization. Moreover, the investigated flavone-based PISs present their stabilities at room temperature, indicating that resin containing these systems barely require special storage requirements. Thiol-ene polymerization initiated by the flavone-derivatives-based PISs is also investigated.

Photopolymerization allows fast production of materials with special properties; however, a short wavelength of light is required for most commercial photoinitiating systems and the oxygen inhibition effect for the free radical polymerization has limited possible applications. Herein, we investigate thiol-ene photopolymerization with various types of “ene” derivatives and thiols using our previously reported photoinitiator 2-(4-methoxystyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine (triazine) alone or in combination with rubrene or 1,4-bis(isopropylamino)anthraquinone (SB36) as the photoinitiating systems to trigger polymerization under irradiation with blue, green, and red LEDs. An analysis of photopolymerization kinetics and the effects of different light irradiation conditions, chemical structures, composites of “ene” and thiol monomers, and air on the thiol-ene photopolymerization reaction are presented. Specifically, rates of photopolymerization of all thiol-ene formulations decrease as the wavelength of irradiation increases and show no significant difference when polymerization occurs under air or in laminate. Mechanical properties and homogeneity of the photocured samples are analyzed and demonstrated that all thiol-ene formulations appear to have a homogeneous network. Regarding mechanical properties, with a lower amount of thiol incorporated in the network, the storage modulus and the glass transition temperature (T ) of the photocured product increased. Storage stability of thiol-ene formulations is also studied and 5-hydroxy-1,4-naphthoquinone (5HNQ), a naturally derived dye derivative, is found to be successful in inhibiting premature gelation in thiol-ene systems without significantly affecting the photopolymerization performance.

The design and development of versatile initiators for various types of polymerization reactions, i.e. thermal-/photo-crosslinked/controlled polymerizations, is highly interesting to fabricate high-performance polymer materials. Herein, we synthesized two N-aryl glycine-based initiators, N-(1-naphthyl)glycine (NNG) and N-(1-pyrenyl)glycine (NPYG), and investigated their ability to trigger thermal- or light-induced polymerizations. Relevant photochemical mechanisms to generate reactive species were studied by steady state photolysis, fluorescence, and electron paramagnetic resonance spin-trapping techniques. The synthesized N-aryl glycine-based initiators can act as monocomponent photoinitiators or be incorporated into multicomponent photoinitiating systems for free radical or cationic crosslinked photopolymerization under diverse blue LEDs. Moreover, NPYG was also capable of initiating reversible addition–fragmentation chain transfer polymerization under either thermal- or light-induced reaction.

Xiaotong Peng,1 Zhirong Zhang,1 Yanqun Mo,1 Junliang Liu,1 Shuo Wang,2 Huining Liu1 1Department of Gynaecology and Obstetrics, Xiangya Hospital, Central South University, Changsha, 410008, People’s Republic of China; 2Department of Orthopaedics, Shanghai Jiaotong University Affiliated Sixth People’s Hospital, Shanghai, 200233, People’s Republic of ChinaCorrespondence: Huining LiuDepartment of Gynecology and Obstetrics, Xiangya Hospital, Central South University, Changsha, 410011, Hunan, People’s Republic of ChinaEmail lliuhuining@163.comShuo WangDepartment of Orthopaedics, Shanghai Jiaotong University Affiliated Sixth People’s Hospital, Shanghai, 200233, People’s Republic of ChinaEmail shuowang97@126.comObjective: The aim of the current research was to construct a miRNA-transcription factor (TF)-target gene regulatory network in order to investigate the mechanism underlying choriocarcinoma and to verify the network through the overexpression or silencing of hub miRNAs in vitro.Materials and Methods: A mRNA expression dataset and two miRNA expression datasets were analysed to identify differentially expressed genes (DEGs) and miRNAs (DEMs) between normal cells and choriocarcinoma cells. The top 400 upregulated and downregulated DEGs were identified as candidate DEGs, which were then mapped to construct protein–protein interaction (PPI) networks and select hub genes. Moreover, the DGIdb database was utilized to select candidate drugs for hub genes. Moreover, DEM target genes were predicted through the miRWalk2.0 database and overlaid with candidate DEGs to identify the differentially expressed target genes (DETGs). Furthermore, we established miRNA-TF-target gene regulatory networks and performed functional enrichment analysis of hub DEMs. Finally, we transfected mimics or inhibitors of hub DEMs into choriocarcinoma cells and assessed cell proliferation and migration to verify the vital role of hub DEMs in choriocarcinoma.Results: A total of 140 DEMs and

The use is described of scanning electron microscopy (SEM), fluorescence stereo microscopy and transmission electron microscopy (TEM), together with in situ chemical analysis using energy-dispersive spectrometry to study the biofilm formed on the surfaces of chalcopyrite during bio-oxidation in the presence of Acidothiobacillus ferrooxidans. The results showed that the cells became attached to the chalcopyrite surface but SEM and fluorescence stereo-microscopy indicated that there were no bacteria on the mineral surface. This was attributed to the covering of the attached bacteria with deposited jarosite and elemental sulphur. After 15 days the chalcopyrite surface became covered with a smooth film, some of which became detached. SEM images showed a bacterial community was present on the underside of the detached films and TEM images indicated that the bacteria were enclosed in extracellular polymeric substances. The biofilm consisted of bacteria and floccules., The use is described of scanning electron microscopy (SEM), fluorescence stereo microscopy and transmission electron microscopy (TEM), together with in situ chemical analysis using energy-dispersive spectrometry to study the biofilm formed on the surfaces of chalcopyrite during bio-oxidation in the presence of Acidothiobacillus ferrooxidans. The results showed that the cells became attached to the chalcopyrite surface but SEM and fluorescence stereo-microscopy indicated that there were no bacteria on the mineral surface. This was attributed to the covering of the attached bacteria with deposited jarosite and elemental sulphur. After 15 days the chalcopyrite surface became covered with a smooth film, some of which became detached. SEM images showed a bacterial community was present on the underside of the detached films and TEM images indicated that the bacteria were enclosed in extracellular polymeric substances. The biofilm consisted of bacteria and floccules.