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The analysis of microplastics (MP) becomes more difficult for smaller sizes, especially in complex matrices such as sediment of natural waters. In this work, we analyzed MPs in sediment using laser direct infrared (LDIR) imaging, a relatively new technique in environmental MP studies. Sediment samples were spiked with analytical surrogates (polyethylene spheres), and subjected to density separation, wet peroxide oxidation, calcite removal, and filtration. The extracted particles were coated on to a low-emissivity glass slide which was first examined on a stereomicroscope. Six slides (two sediment samples and four different blanks) were further analyzed using an Agilent LDIR system. Approximately 520 and 430 MP/g were found in the two samples, with diameter ranging 20–3384 μm and 84% being smaller than 100 μm. The increase in particle count with decreasing particle sizes followed a power law curve, suggesting that a large portion of the smaller MPs was generated by the breakdown of larger plastic pieces. Major polymers found in this work included polyamide, polyester, polytetrafluoroethylene, and polyacetal. Most MPs were fragments, while beads and fiber were also found. In the two sediment samples, 14% and 46% of the total particles, respectively, were composed of non-plastic micro-sized particles, including natural polyamide, cellulose, chitin, rubber, and “unknown”. Challenges, potential biases, and uncertainties are discussed. This work is the first application of LDIR imaging on MPs in natural sediment.

In this work, MXene Ti3C2Tx-derived nitrogen-functionalized heterophase TiO2 homojunctions (N-MXene) were prepared via the urea-involved solvothermal treatment with varying reaction time as the sensing layer to detect trace NH3 gas at room temperature (20 °C). Compared with no signal for the pristine MXene counterpart, the 18 h-treated sensors (N-MXene-18) achieved a detection limit of 200 ppb with an inspiring response that was 7.3% better than the existing MXene-involved reports thus far. Also, decent repeatability, stability, and selectivity were demonstrated. It is noteworthy that the N-MXene-18 sensors delivered a stronger response, more sufficient recovery, and quicker response/recovery speeds under a humid environment than those under dry conditions, proving the significance of humidity. Furthermore, to suppress the effect of the fluctuation of humidity on NH3 sensing during the tests, a commercial waterproof polytetrafluoroethylene (PTFE) membrane was anchored onto the sensing layer, eventually bringing about humidity-independent features. Both nitrogen doping and TiO2 homojunctions constituted by mixed anatase and rutile phases were primarily responsible for the performance improvement with respect to pristine MXene. This work showcases the enormous potential of N-MXene materials in trace NH3 detection and offers an alternative strategy to realize both heteroatom doping and partial oxidation of MXene that is applicable in future optoelectronic devices.

Persistent activation of signal transducer and activator of transcription 3 (STAT3) is frequently reported in cancers and plays important roles in tumor progression. Therefore, directly targeting persistent STAT3 signaling is an attractive cancer therapeutic strategy. The aim of this study is to test the inhibitory efficacy of novel STAT3 small molecule inhibitors, LLY17 and LLL12B, in combination with irradiation in human medulloblastoma cells. Both LLY17 and LLL12B inhibit the IL-6-induced and persistent STAT3 phosphorylation in human medulloblastoma cells. Irradiation using 4 Gy alone exhibits some inhibitory effects on medulloblastoma cell viability, and these effects are further enhanced by combining with either STAT3 inhibitor. Irradiation alone also shows certain inhibitory effects on medulloblastoma cell migration and invasion and the combination of LLY17 or LLL12B with irradiation further demonstrates greater inhibitory effects than monotherapy. STAT3 inhibitor alone or irradiation alone exhibits some suppression of medulloblastoma tumorsphere growth, and the combination of LLY17 or LLL12B and irradiation exhibits greater suppression of tumorsphere growth than monotherapy. Combining either STAT3 inhibitor with irradiation reduces the expression of STAT3 downstream targets, Cyclin D1 and Survivin, and induces apoptosis in medulloblastoma cells. These results support that combination of a potent STAT3 inhibitor such as LLY17 or LLL12B with irradiation is an effective and novel therapeutic approach for medulloblastoma.

Li4SiO4 crystal is a candidate material for tritium breeder material. Vacancy defects and He atoms will be produced in the crystal after neutron irradiation in fusion reactor. In previous research, we learned vacancy defects mainly include VO0, VO2+, and VLi0, meanwhile, He atoms are easy to migrate and aggregate in the crystal. In order to understand the relationship between vacancy defects and He atoms, we use density functional theory (DFT) to study the interaction mechanism between vacancy and He atom. The results show that the local stable sites of He atoms are related to the surrounding charge distribution. VO2+ and VLi0 can capture interstitial He atoms, and it is difficult to escape the vacancies, thereby increasing the nucleation center of He atoms. VO0 promotes the diffusion of He atoms in the interstitial space, which will cause small helium bubbles to merge more easily.

Phedimus aizoon L. is a drought-resistant Chinese herbal medicine and vegetable. However, its drought tolerant limit and the mechanism of drought tolerance are unknown, which restricts the promotion of water-saving cultivation of Phedimus aizoon L. in arid areas. To solve the above problem, we carried out a 30-day-long drought stress experiment in pots that presented different soil water contents and were divided into four groups: control check, 75–80% of the maximum water-holding capacity (MWHC); mild drought, 55–60%; moderate drought, 40–45%; and severe drought, 20–25%. The dynamic changes in both plant physiological indexes from 10 to 30 days and leaf anatomical structure on the 30th day of stress were recorded. The results show that Phedimus aizoon L. grew normally under mild drought stress for 30 days, but the growth of the plants became inhibited after 20 days of severe drought and after 30 days of moderate drought. At the same time, Phedimus aizoon L. physiologically responded to cope with drought stress: the growth of the root system accelerated, the waxy layer of the leaves thickened, and the dark reactions of the plants transformed from those of the C3 cycle to CAM. The activity of antioxidant enzymes (SOD, POD and CAT) continuously increased to alleviate the damage caused by drought stress. To ensure the relative stability of the osmotic potential, the contents of osmoregulatory substances such as proline, soluble sugars, soluble protein and trehalose increased correspondingly. Although Phedimus aizoon L. has strong drought stress resistance, our experimental results show that the soil available water content should not be less than 27% during cultivation.

Autophagy, a process for self-degradation of intracellular components and dysfunctional organelles, is closely related with neurodegenerative diseases. It has been shown that cadmium (Cd) induces neurotoxicity partly by impairing autophagy. However, the underlying mechanism is not fully elucidated. In this study, we show that Cd induced expansion of autophagosomes with a concomitant abnormal expression of autophagy-related (Atg) proteins in PC12 cells and primary murine neurons. 3-MA, a classical inhibitor of autophagy, attenuated Cd-induced expansion of autophagosomes and apoptosis in the cells. Further investigation demonstrated that Cd activated JNK pathway contributing to autophagosome expansion-dependent neuronal apoptosis. This is supported by the findings that pharmacological inhibition of JNK with SP600125 or expression of dominant negative c-Jun markedly attenuated Cd-induced expansion of autophagosomes and abnormal expression of Atg proteins, as well as apoptosis in PC12 cells and/or primary neurons. Furthermore, we noticed that chelating intracellular free Ca2+ ([Ca2+]i) with BAPTA/AM profoundly blocked Cd-elicited activation of JNK pathway and consequential expansion of autophagosomes, abnormal expression of Atg proteins, and apoptosis in the neuronal cells. Similar events were also seen following prevention of [Ca2+]i elevation with EGTA or 2-APB, implying a Ca2+-dependent mechanism involved. Taken together, the results indicate that Cd impairs autophagy leading to apoptosis by Ca2+-dependent activation of JNK signaling pathway in neuronal cells. Our findings highlight that manipulation of intracellular Ca2+ level and/or JNK activity to ameliorate autophagy may be a promising intervention against Cd-induced neurotoxicity and neurodegeneration.

Signal Transducer and Activator of Transcription 3 (STAT3) is a transcription factor and an oncogene product, which plays a pivotal role in tumor progression. Therefore, targeting persistent STAT3 signaling directly is an attractive anticancer strategy. The aim of this study is to test the efficacy of a novel STAT3 small molecule inhibitor, LLL12B, in suppressing medulloblastoma cells in vitro and tumor growth in vivo. LLL12B selectively inhibited the induction of STAT3 phosphorylation by interleukin-6 but not induction of STAT1 phosphorylation by INF-γ. LLL12B also induced apoptosis in human medulloblastoma cells. In addition, LLL12B exhibited good oral bioavailability in vivo and potent suppressive activity in tumor growth of medulloblastoma cells in vivo. Besides, combining LLL12B with cisplatin showed greater inhibition of cell viability and tumorsphere formation as well as induction of apoptosis comparing to single agent treatment in medulloblastoma cells. Furthermore, LLL12B and cisplatin combination exhibited greater suppression of medulloblastoma tumor growth than monotherapy in vivo. The present study supported that LLL12B is a novel therapeutic agent for medulloblastoma and the combination of LLL12B with a chemotherapeutic agent cisplatin may be an effective approach for medulloblastoma therapy.

In wheat (Triticum aestivum L.), breeding efforts have focused intensively on improving grain yield and quality. For quality, the content and composition of seed storage proteins (SSPs) determine the elasticity of wheat dough and flour processing quality. Moreover, starch levels in seeds are associated with yield. However, little is known about the mechanisms that coordinate SSP and starch accumulation in wheat. In this study, we explored the role of the endosperm-specific NAC transcription factor TaNAC019 in coordinating SSP and starch accumulation. TaNAC019 binds to the promoters of TaGlu-1 loci, encoding high molecular weight glutenin (HMW-GS), and of starch metabolism genes. Triple knock-out mutants of all three TaNAC019 homoeologs exhibited reduced transcript levels for all SSP types and genes involved in starch metabolism, leading to lower gluten and starch contents, and in flour processing quality parameters. TaNAC019 directly activated the expression of HMW-GS genes by binding to a specific motif in their promoters and interacting with the TaGlu-1 regulator TaGAMyb. TaNAC019 also indirectly regulated the expression of TaSPA, an ortholog of maize Opaque2 that activates SSP accumulation. Therefore, TaNAC019 regulation of starch- and SSP-related genes has key roles in wheat grain quality. Finally, we identified an elite allele (TaNAC019-BI) associated with flour processing quality, providing a candidate gene for breeding wheat with improved quality.

In this study, we developed ashless cellulose filter papers as calibration standards in laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to rapidly determine multi-element concentrations in airborne fine particulate matter (PM2.5). To achieve this, the papers were treated by immersion in standard solutions, followed by evaporation of the solutions. The homogeneity of the paper standards was studied, and the results demonstrated that the elements were homogeneously distributed at the paper centers with slight fluctuations (i.e., relative standard derivation ≦ 8%). The instrument signal drift and instability were compensated using a pseudo internal standard (197Au). The limits of detection established for LA-ICP-MS were obtained by the ablation of 11 lines on the procedural blank filter paper containing 0.5% HNO3, with values ranging from 0.01 (Sr) to 0.49 μg g−1 (Fe). The accuracy of the LA-ICP-MS determinations was validated using certified reference materials (CRMs) and analyzed using six line scans. The results showed acceptable analytical errors (

The behavior of He atoms in γ-Fe single crystal is studied using the molecular dynamics simulation (MD) methods. Simulations show that the melting point of bulk γ-Fe computed by single-phase and dual-phase methods is 1935 and 1727 ± 1 K, respectively. There is evidence that the diffusion of He clusters is closely related to the cluster size and temperature and at high temperatures (above 1500 K), large clusters will break up into small clusters and quickly separate from the original clusters. The study on the diffusion behaviors of He clusters helps us to better understand the formation of He bubbles and the fusion of two He bubbles. It was confirmed that the He atom can migrate to the subsurface, but it is difficult to escape from the surface and diffuse to the vacuum slab. This work provides useful information for further theoretical and experimental research on the evolution behaviors of He in materials.

Seventy-five wild tilapia samples from six rivers (ten sites) in Guangxi province were collected and analyzed for 53 organochlorine compounds. DDTs, endosulfan, and PCBs were the most dominant compounds found in this study. Tiandong County (TD) and Guigang City (GG) sites were found to be heavily contaminated with high levels of endosulfan (385–925 ng/g lw) and/or DDTs (20.1–422 ng/g lw). The diagnostic ratios indicated that the residues of DDTs and endosulfan in wild tilapia are associated with historical applications as well as the recent introduction of technical DDTs and endosulfan at some sampling sites. The correlation between total length, body mass, and organochlorines (OCs) was higher than the correlation between age and lipid content. There was no significant correlation between organochlorine pesticides (OCPs) and lipid content. Therefore, for organisms, the feeding intensity (related to length and mass) of fish could better reflect degree of pollution than exposure time (age) of fish. The hazardous ratios for the 50th and 95th percentile data of OCPs and PCBs in fish were both below 1, suggesting that daily exposure to OCPs and PCBs yields a lifetime cancer risk lower than 1 in 10,000.

The interstitial stability and diffusion properties of helium in Li4SiO4 crystals are studied by using density functional theory (DFT) simulation. All types of interstitial sites are established. Possible helium locally stable (LS) positions in interstitial sites are examined, and the formation energies are calculated. The LS site of helium interstitial in Li4SiO4 crystals is determined, the diffusion paths and barriers of the helium between adjacent LS sites are calculated by the CI-NEB method. The results show that there are 11 different LS sites in the Li4SiO4 crystal, and the formation energies are in the range of 0.770–1.034 eV. Using CI-NEB calculations, we find that the diffusion of helium is anisotropic along different directions. The most favorable diffusion path appears at the center of the crystal and diffusion along the direction, and the diffusion barrier is 0.16 eV.

At present, the seismic design research of underground structures in loess areas is lagging behind compared with practical engineering requirements. The selection of seismic calculation methods and parameters does not consider the influences of the special geological conditions in various regions, so their usefulness is limited. Based on the above problems, a modified displacement-based method (DBM) was proposed and its application was compared with the most commonly used methods of analysis (force-based design method, displacement-based design method, detailed equivalent static analysis numerical method, and the full dynamic time-history method). The results were also validated by considering data from shaking table tests conducted on a case study involving the underground Feitian Road subway station in Xi’an. The results show that compared with DBM, the average accuracy of the modified DBM technique is improved by 41.65%. The modified DBM offers good accuracy, simplicity in its model, a rapid analysis time, and easy convergence.

Oxidative stress is closely related to the pathogenesis of Parkinson's disease (PD), a typical neurodegenerative disease. NADPH oxidase 2 (NOX2) is involved in hydrogen peroxide (H2O2) generation. Recently, we have reported that H2O2 and PD toxins, including 6-hydroxydopamine (6-OHDA), 1-Methyl-4-phenylpyridin-1-ium (MPP+) and rotenone, induce neuronal apoptosis by inhibiting mTOR pathway. Here, we show that 6-OHDA, MPP+ or rotenone induced H2O2 generation by upregulation of NOX2 and its regulatory proteins (p22phox, p40phox, p47phox, p67phox, and Rac1), leading to apoptotic cell death in PC12 cells and primary neurons. Pretreatment with catalase, a H2O2-scavenging enzyme, significantly blocked PD toxins-evoked NOX2-derived H2O2, thereby hindering activation of AMPK, inhibition of Akt/mTOR, induction of apoptosis in neuronal cells. Similar events were also seen in the cells pretreated with Mito-TEMPO, a mitochondria-specific superoxide scavenger, implying a mitochondrial H2O2-dependent mechanism involved. Further research revealed that inhibiting NOX2 with apocynin or silencing NOX2 attenuated the effects of PD toxins on AMPK/Akt/mTOR and apoptosis in the cells. Of importance, ectopic expression of constitutively active Akt or dominant negative AMPKα, or inhibition of AMPK with compound C suppressed PD toxins-induced expression of NOX2 and its regulatory proteins, as well as consequential H2O2 and apoptosis in the cells. Taken together, these results indicate that certain PD toxins can impede the AMPK/Akt-mTOR signaling pathway leading to neuronal apoptosis by eliciting NOX2-derived H2O2. Our findings suggest that neuronal loss in PD may be prevented by regulating of NOX2, AMPK/Akt-mTOR signaling and/or administering antioxidants to ameliorate oxidative stress.

Eight fish species were sampled from a coastal coral reef ecosystem near Weizhou Island, South China Sea, to investigate the composition profiles and bioaccumulation of organochlorines (OCs). The total concentrations of 18 organochlorine pesticides (OCPs) and 22 polychlorinated biphenyls (PCBs) were found to be 26.5–452 ng/g lw and 0.87–19.8 ng/g lw, respectively. The contaminant distribution pattern indicated that agrochemical sources were more important than industrial sources, and that historical residues remain the primary source of OCs in Weizhou Island. Bioaccumulation factors (BAFs) indicated that dichlorodiphenyltrichloroethanes was bioaccumulating with log BAFs ranging from 3.53 to 5.21. Some congeners diverged from the general trend predicted by the logarithm octanol-water partition coefficient (log Kow); this was mainly attributable to differences in the bioaccumulation potentials of these congeners in the studied samples. Trophic magnification factors demonstrated that aldrin, endrin, and dieldrin undergo significant trophic dilution, while the other six OC compounds undergo trophic magnification in the food chain. The presence of OCP congeners was also probably affected by their metabolism in fish tissues. The estimated daily intakes of OCPs via fish consumption by residents ranged from 0.05 to 5.45 ng/kg body weight/day, which is below the acceptable daily intake recommended by the FAO/WHO.

WCoB based cermets were prepared by spark plasma sintering at sintering temperature among 600°C-1200 °C. The phase evolution was investigated by detecting density behavior, phase composition, microstructure and mechanical properties during sintering process. The sintering process can be divided into three stages: powder densification, solid phase reaction and liquid phase sintering. WCoB hard phase forms at 1000 °C during solid phase sintering, showing better mechanical properties than Co2B, especially on Vicker's hardness. WCoB hard phase forms on the basis of Co2B binary boride and its content increases in liquid phase sintering stage with high density. The Vicker's hardness and transverse rupture strength (TRS) reach the maximum value of 1262 Hv and 1212 MPa at 1200 °C and 1170 °C, respectively. The fracture toughness reaches the maximum value of 21.8 MPa m1/2 at 1050 °C, and the inter-granular fracture is the main fracture mechanism.

Tailoring transition-metal oxide nanoparticles with two-dimensional carbon has become a favorite way to improve their electrochemical performance. In this study, a composite of reduced graphene oxide was anchored by Co3O4 nanocubes and easily prepared with the assistance of polydopamine (PDA), using a combination of hydrothermal reaction and pyrolysis (Co3O4@PDA-rGO). Polydopamine, which possesses abundant catechol and amine groups, could be easily grafted onto graphene oxide to reduce the aggregation of graphene particles. Furthermore, PDA provided active sites, i.e., catechol and amine groups, which coordinated with Co2+, enabling enrichment of metal ions on the surface of graphene. After the pyrolysis of Co2+-containing PDA-grafted graphene at 400 °C, the Co2+ ions were converted into Co3O4 nanocubes, while the PDA carbonized to form N-doped porous carbon on the surface of graphene. The resulting product, Co3O4@PDA-rGO, demonstrated extraordinary supercapacitive behavior with good cycling stability owing to its unique porous structure as well as the intimate contact between Co3O4 and the carbon matrix.

Δ1-Dehydrogenation is one of the most important reactions for steroid drug modification. Numerous 3-ketosteroid-Δ1-dehydrogenases (KstDs) catalyzing this reaction were observed in various organisms. However, only a few have been characterized and used for substrate conversion. In this study, a promising enzyme (KstD2) from Mycobacterium neoaurum DSM 1381 was purified and characterized. Interestingly, KstD2 displayed a high activity on a range of substrates, including 17α-hydroxypregn-4-ene-3,20-dione (17α-OH-P); androsta-4,9(11)-diene-3,17-dione (NSC 44826); and 4-androstene-3,17-dione (AD). These reactions were performed under optimal conditions at 40 °C and pH 8.0. Noteworthy, both the activity and stability of the enzyme were sensitive to various metal ions. After optimizing the expression and biocatalyst conditions, up to 1586 U mg-1 intracellular KstD activity on AD could be produced. Furthermore, the associated conversion rate was 99% with 30 g L-1 AD after 8 h. On the other hand, we obtained 99%, 90%, and over 80% of conversion with 20 g L-1 NSC 44826; 10 g L-1 16,17α-epoxyprogesterone; and 20 g L-1 17α-OH-P or canrenone, respectively, after 24 h. Sequence homology and structural analyses indicated that the residue R178 located in a unique short loop among cluster 2 is crucial for substrate recognition which was confirmed by mutagenesis. In summary, this study reports on the first purification and characterization of a KstD from cluster 2. Its remarkable properties deserve more attention to potentially lead to further industrial applications.

CO2 mineralisation by industrial wastes is a promising option for mitigating carbon emissions safely and permanently with low material cost. But there is still absence of a detailed understanding on how fly ash properties affect the carbonation reactions. To fill this knowledge gap, five coal combustion fly ashes, Beijing (BJ), Wuhai (WH), Hazelwood (HW), Yallourn (YA) and Loy Yang (LY) ashes, from China and Australia were selected for carbonation studies. Experiments were performed in a batch reactor at 40 and 140 °C with 20 bar initial CO2 pressure, 200 g/L solid to liquid ratio, 450 rpm stirring rate to compare the carbonation performance of the five fly ashes and the effect of fly ash properties on carbonation reactions. Then BJ, YA and HW ashes were then selected for further study in a wide temperature range (40–220 °C) because of their higher CO2 sequestration capacity than the other two ashes. Quantitative X-ray diffractometry (XRD) with Rietveld refinement was used to characterize the crystalline and amorphous phases in fresh and carbonated fly ashes. Scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS) were used to characterize morphological and elemental properties of fresh and carbonated fly ash samples. Compared to LY and WH ashes, BJ, YA and HW ashes displayed much higher CO2 sequestration capacity due to the higher fraction of reactive Ca/Mg-bearing crystalline phases, including lime (CaO) and portlandite (Ca(OH)2) in BJ ash, periclase (MgO) and srebrodolskite (Ca2Fe2O5) in YA ash, and periclase and brucite (Mg(OH)2) in HW ash. Compared to YA and WH ashes, BJ ash displayed faster kinetics of carbonation reactions because the reactant phases of BJ ash were mainly Ca-bearing phases which have higher reactivity with CO2 than Mg-bearing phases. Also, particle size and morphological analyses indicated that the reacted particles displayed a lower porosity and pore area than the fresh sample due to the new precipitates not only depositing on the active surface, but also filling the pores of the fly ash particles, which was responsible for the reduced kinetics with time.

The effects of synthesis parameters, including pH, solvent, and output energy mode, on the synthesis and photocatalytic activity of SnO were investigated. The results exhibited that Cl-doped SnO samples with a particle size of approximately 50 nm were successfully obtained, with a BET surface area of approximately 7 m2/g. These parameters showed weak effects on phase composition, morphology, and particle size; however, they affected the degradation efficiency of SnO samples to MO. The optimum degradation efficiency of SnO samples to MO can be obtained by using an appropriate proportion of water and alcohol, acid condition, and three modes of output.

This study focused on a novel denitrifying Cupriavidus sp. W12, which can perform microbial induced calcium precipitation (MICP) to remove fluoride (F-) under aerobic and anaerobic conditions. Under anaerobic condition, the removal ratios of F-, calcium (Ca2+), and nitrate (NO3-–N) reached 87.52%, 65.03%, and 96.06%, respectively, which were higher than that under aerobic condition (50.17%, 88.21%, and 67.33%, respectively). Higher pH of 8.26 was obtained after 120 h of the strain W12 growth under anaerobic condition than that under aerobic condition (7.77). The F- removal ratio of 98.20% was predicted by the response surface methodology (RSM). Scanning electron microscopy (SEM) images of anaerobic precipitation were dense and porous. CaCO3, Ca5(PO4)3OH, Ca5(PO4)3F, and CaF2 were determined by X-ray diffraction (XRD) and energy dispersive spectrometer (EDS). Self-aggregation of bacteria and adsorption of biological crystal seeds were the determinant of the precipitates formation. The results of infrared spectrometer (FTIR) and excitation-emission matrix (EEM) showed that anaerobic extracellular polymeric substances (EPS) expression led the proportion of hydroxylapatite in the precipitates increased. As the first report on the anaerobic MICP to remove F-, it provides a theoretical basis for the remediation of F-, Ca2+, and NO3-–N in groundwater.

Ovarian cancer is the fifth most common cause of cancer deaths among American women. Platinum and taxane combination chemotherapy represents the first-line approach for ovarian cancer, but treatment success is often limited by chemoresistance. Therefore, it is necessary to find new drugs to sensitize ovarian cancer cells to chemotherapy. Persistent activation of Signal Transducer and Activator of Transcription 3 (STAT3) signaling plays an important role in oncogenesis. Using a novel approach called advanced multiple ligand simultaneous docking (AMLSD), we developed a novel nonpeptide small molecule, LLL12B, which targets the STAT3 pathway. In this study, LLL12B inhibited STAT3 phosphorylation (tyrosine 705) and the expression of its downstream targets, which are associated with cancer cell proliferation and survival. We showed that LLL12B also inhibits cell viability, migration, and proliferation in human ovarian cancer cells. LLL12B combined with either paclitaxel or with cisplatin demonstrated synergistic inhibitory effects relative to monotherapy in inhibiting cell viability and LLL12B-paclitaxel or LLL12B-cisplatin combination exhibited greater inhibitory effects than cisplatin-paclitaxel combination in ovarian cancer cells. Furthermore, LLL12B-paclitaxel or LLL12B-cisplatin combination showed more significant in inhibiting cell migration and growth than monotherapy in ovarian cancer cells. In summary, our results support the novel small molecule LLL12B as a potent STAT3 inhibitor in human ovarian cancer cells and suggest that LLL12B in combination with the current front-line chemotherapeutic drugs cisplatin and paclitaxel may represent a promising approach for ovarian cancer therapy.

A simultaneous denitrifying and mineralizing bacterium, Pseudomonas sp. WZ39 was isolated for fluoride (F−), nitrate (NO3−-N), and calcium (Ca2+) removal. Strain WZ39 exhibited a remarkable defluoridation efficiency of 87.49% under a pH of 6.90, F− and Ca2+ concentration of 1.99 and 201.88 mg L−1, respectively. EEM, SEM–EDS, XRD, and FTIR analyses elucidated the chemical adsorption and co-precipitation with calcium salt contributed to the removal of F−. The mechanisms of biomineralization were also investigated by determining the role of bound and unbound extracellular polymeric substances (EPS), cell wall, and calcium channel in nucleation. The results showed that bacteria can promote nucleation on the templates of cell walls or EPS through the electrostatic effect. The presence of the calcium channel blocker inhibited the transport of intracellular Ca2+ to the extracellular environment. The outcome of the present research can provide a theoretical basis for the understanding of MICP phenomenon and the efficient treatment of F− containing groundwater.

Alloying with transition elements is proven to be an effective way to improve the methanol electro-oxidation reaction (MOR) and oxygen reduction reaction (ORR) activities of Pt catalysts for direct methanol fuel cells (DMFCs). Through a process of rapid solidification and two-step dealloying, we have successfully fabricated three-dimensional mesoporous PtM (M = Co, Cu, Ni) nanowire catalysts, which show much enhanced electrocatalytic properties towards MOR and ORR in comparison with the commercial Pt/C catalyst. Electrochemical tests indicate that alloying with Cu presents the best ORR activities, the half-wave potential of which is 42 mV positively shifted compared with the commercial Pt/C (0.892 V vs. RHE). Meanwhile, the PtM nanowire catalysts also possess good CO tolerance as well as stability for 10 000 cycles of cyclic voltammetry scanning. This convenient preparation method is promising for the development of high performance electrocatalysts for MOR and ORR in DMFCs.

In this research, an immobilized biofilm reactor was established for the simultaneous removal of calcium (Ca2+), fluoride (F-), nickel (Ni2+), and nitrate (NO3--N) by microbial induced calcium precipitation (MICP). The operating parameters of the reactor, hydraulic retention time (HRT: 4, 8, and 12 h), influent Ca2+ concentration (36.0, 108.0, and 180.0 mg L−1), and influent Ni2+ concentration (0.0, 3.0, and 6.0 mg L−1) were discussed. Under the HRT of 12 h, influent Ca2+ concentration of 180.0 mg L−1, and influent Ni2+ concentration of 3.0 mg L−1, the removal ratios of Ca2+, F-, Ni2+, and NO3--N reached 45.31%, 79.55%, 85.11%, and 55.29%, respectively, which was the reactor stable operation performance. The SEM revealed the morphology of calcium-precipitated bio-crystals. XPS showed the Ca2+ and Ni2+ precipitate components and XRD further revealed the formation of CaCO3, Ca5(PO4)3OH, and NiCO3 precipitation. Nitrogen (N2) was the main gas produced in the reactor. Fluorescence spectroscopy manifested that extracellular polymers played an important role in the organism nucleation. High-throughput sequencing exhibited that Acinetobacter sp. H12 was the dominant bacterial group. This study provided a new insight for simultaneous remediation of Ca2+, F-, Ni2+, and NO3--N in water bodies.

Lithium chloride (LiCl), a pharmacological compound, was effective in reducing inflammation, but whether it can protect against abdominal aortic aneurysm (AAA) is largely unknown. This study is designed to investigate therapeutic effects of LiCl on AAA and the potential mechanism. Rat AAA models were induced by periaortic application of CaCl2. AAA rats were treated by daily intraperitoneal injection of LiCl or vehicle alone to study the protection effects of LiCl in vivo. Rat primary vascular smooth muscle cells (VSMCs) stimulated with tumor necrosis factor (TNF)-α served as an in vitro model. LiCl treatment prevented the development of AAA through inhibiting the inflammatory cells infiltration and inflammatory cytokines overproduction, as well as attenuating superoxide production and elastin degradation in aorta of AAA rats. Additionally, the downregulation of p-GSK3β(Ser9) and SIRT1, upregulation of NF-κB(p-65), MMP-2 and MMP-9 in AAA were abolished by LiCl treatment. In vitro by upregulating p-GSK3β(Ser9), LiCl significantly induced SIRT1 expression, along with inhibition of the NF-κB activation and decreased elastin level elicited in VSMCs by TNF-α stimulation. SIRT1 activator SRT1720 achieved similar repressive effects as LiCl on TNF-α-induced NF-κB activation and decreased elastin in VSMCs. Moreover, administration of LiCl also caused regression of established rats AAA. This study provided the first evidence that LiCl prevented the development of AAA through inhibiting inflammation, MMPs, and superoxide production, and facilitating the biosynthesis of elastin. The beneficial effect of LiCl may be mediated by regulation GSK3β/SIRT1/NF-κB cascade.

The epigenetic regulation mechanisms for toxicity induction of nanoplastics in organisms remain largely unknown. In Caenorhabditis elegans, we found that prolonged exposure to 1–100 μg/L polystyrene nanoparticles (PS-NPs) decreased expression of MET-2, a H3K9 methyltransferase. Meanwhile, RNAi knockdown of met-2 suppressed the PS-NPs toxicity in inducing production of reactive oxygen species (ROS) and in decreasing locomotion behavior, which suggesting that the decrease in MET-2 expression reflected a protective response. This resistance to PS-NPs toxicity could be further detected in worms with met-2 RNAi knockdown in both intestinal cells and germline cells. In PS-NPs exposed worms, intestinal RNAi knockdown of met-2 significantly increased expressions of daf-16, bar-1, and elt-2. Intestinal RNAi knockdown of daf-16, bar-1, or elt-2 suppressed the resistance of met-2(RNAi) worms to PS-NPs toxicity, suggesting that MET-2 functioned upstream of ELT-2, BAR-1, and DAF-16 in intestinal cells to control PS-NPs toxicity. Moreover, in PS-NPs exposed worms, germline RNAi knockdown of met-2 significantly decreased expressions of wrt-3 and pat-12. RNAi knockdown of wrt-3 or pat-12 further inhibited the susceptibility of worms overexpressing germline MET-2 to PS-NPs toxicity, suggesting that MET-2 functioned upstream of PAT-12 and WRT-3 in germline cells to control PS-NPs toxicity. Therefore, our data provided an important molecular basis for MET-2-mediated methylation regulation in causing protective response to nanoplastics in organisms.

Ovarian cancer is the fifth most common cause of cancer deaths among American women. Platinum and taxane combination chemotherapy represents the first-line approach for ovarian cancer, but treatment success is often limited by chemoresistance. Therefore, it is necessary to find new drugs to sensitize ovarian cancer cells to chemotherapy. Persistent activation of Signal Transducer and Activator of Transcription 3 (STAT3) signaling plays an important role in oncogenesis. Using a novel approach called advanced multiple ligand simultaneous docking (AMLSD), we developed a novel nonpeptide small molecule, LLL12B, which targets the STAT3 pathway. In this study, LLL12B inhibited STAT3 phosphorylation (tyrosine 705) and the expression of its downstream targets, which are associated with cancer cell proliferation and survival. We showed that LLL12B also inhibits cell viability, migration, and proliferation in human ovarian cancer cells. LLL12B combined with either paclitaxel or with cisplatin demonstrated synergistic inhibitory effects relative to monotherapy in inhibiting cell viability and LLL12B-paclitaxel or LLL12B-cisplatin combination exhibited greater inhibitory effects than cisplatin- paclitaxel combination in ovarian cancer cells. Furthermore, LLL12B-paclitaxel or LLL12B-cisplatin combination showed more significant in inhibiting cell migration and growth than monotherapy in ovarian cancer cells. In summary, our results support the novel small molecule LLL12B as a potent STAT3 inhibitor in human ovarian cancer cellsand suggest that LLL12B in combination with the current front-line chemotherapeutic drugs cisplatin and paclitaxel may represent a promising approach for ovarian cancer therapy.

Occurrence, behavior, and fate of 11 OPEs in multiple environmental matrices, which include air, rainwater, dustfall, paddy soil, irrigation water, and rice plants from nine subtropical paddy fields of South China, were investigated. The total concentrations of 11 OPEs (∑11OPEs) in all matrices are generally higher in the urban areas than in rural areas, and they are higher in summer than in fall. However, both urban and rural areas showed a similar composition profile of OPEs, indicating that the OPEs come from similar sources in the two areas. Except for irrigation water, significant positive correlations of ∑11OPEs were observed between air and the other five matrices. The exchange and partition of OPEs among air, soil, and water demonstrate that most of OPEs were transferred from air into water and soil, and from water into soil. Thus, the air may be an important source of OPEs in the paddy fields, and the soil may act as a principal environmental reservoir of OPEs. The contribution of air-soil exchange, atmospheric deposition (rainwater plus dustfall), and irrigation water to the total input fluxes of OPEs (2100 ± 980 ng/m2/day) reached an average of 19%, 38% (37% + 1%), and 43%, respectively. The water (rainwater plus irrigation water) is the primary medium transferring the OPEs into the paddy fields and contributed to the input flux by 80%. Output flux of OPEs via mature rice plants was about 220 μg/m2, 2% of which were presented in rice, and the remaining 98% may be re-released into the environment through the pathway of straw turnover or burning. Dietary exposure via rice was much higher than inhalation exposure, dust ingestion, and dermal absorption via dust. However, no data shows that all of the intakes via the four exposure pathways could cause the risks to human health at present.

Caenorhabditis elegans is a useful animal model to determine the underlying mechanism for the response to simulated microgravity. In this study, we employed C. elegans as an animal model to investigate the role of lipid metabolic sensors in regulating the response to simulated microgravity. Among the lipid metabolic sensors, simulated microgravity treatment could increase the expressions of sbp-1 and mdt-15. RNAi knockdown of sbp-1 or mdt-15 induced a susceptibility to toxicity of simulated microgravity, suggesting the alteration in SBP-1 and MDT-1 mediated a protective response to simulated microgravity. Tissue-specific activity analysis demonstrated that both MDT-15 and SBP-1 could act in the intestine to regulate the response to simulated microgravity. Genetic interaction analysis further indicated that intestinal MDT-15 acted upstream of SBP-1 to regulate the response to simulated microgravity. During the control of response to simulated microgravity, fatty acyl CoA desaturase FAT-6 was identified as the downstream target of intestinal SBP-1. Therefore, the identified signaling cascade of MDT-15-SBP-1-FAT-6 suggested the important function of lipid metabolic sensors in mediating a novel intestinal signaling pathway to regulate the response to simulated microgravity in nematodes.

B cell activating factor from the TNF family (BAFF) is implicated in not only the physiology of normal B cells, but also the pathophysiology of aggressive B cells related to malignant and autoimmune diseases. Autophagy plays a crucial role in balancing the beneficial and detrimental effects of immunity and inflammation. However, little is known about whether and how excessive BAFF mediates autophagy contributing to B-cell proliferation and survival. Here, we show that excessive human soluble BAFF (hsBAFF) inhibited autophagy with a concomitant reduction of LC3-II in normal and B-lymphoid (Raji) cells. Knockdown of LC3 not only potentiated hsBAFF inhibition of autophagy, but also attenuated hsBAFF activation of Akt/mTOR pathway, thereby diminishing hsBAFF-induced B-cell proliferation/viability. Further, we found that hsBAFF inhibition of autophagy was Akt/mTOR-dependent. This is supported by the findings that hsBAFF increased mTORC1-mediated phosphorylation of ULK1 (Ser757); Akt inhibitor X, mTORC1 inhibitor rapamycin, mTORC1/2 inhibitor PP242, expression of dominant negative Akt, or knockdown of mTOR attenuated hsBAFF-induced phosphorylation of ULK1, decrease of LC3-II level, and increase of cell proliferation/viability. Chelating intracellular free Ca2+ ([Ca2+]i) with BAPTA/AM or preventing [Ca2+]i elevation using EGTA or 2-APB profoundly blocked hsBAFF-induced activation of Akt/mTOR, phosphorylation of ULK1 and decrease of LC3-II, as well as increase of cell proliferation/viability. Similar effects were observed in the cells where CaMKII was inhibited by KN93 or knocked down by CaMKII shRNA. Collectively, these results indicate that hsBAFF inhibits autophagy promoting cell proliferation and survival through activating Ca2+-CaMKII-dependent Akt/mTOR signaling pathway in normal and neoplastic B-lymphoid cells. Our findings suggest that manipulation of intracellular Ca2+ level or CaMKII, Akt, or mTOR activity to promote autophagy may be exploited for prevention of excessive BAFF-induced aggressive B lymphocyte disorders and autoimmune diseases.

A new hypothesis that seed crystals (SC) and bacteria based on microbially induced calcium precipitation (MICP) synergistically remove fluoride (F−) from groundwater was proposed, with a focus on evaluating the defluoridation potential of this method and revealing its F− removal mechanism. The crucial conditions were optimized to reduce preparation and operation costs. SC furnished more available binding sites due to the existence of bacteria, and the reuse experiments showed that the defluoridation efficiency of SC still remained a high level after 14 cycles (70.10%), with a residual F− concentration of 0.96 mg L−1. The SEM-EDS, FTIR and XRD analyses indicated the predominant F− removal mechanism of SC could be ascribed to the chemisorption, ion exchange, and co-precipitation. Moreover, ion exchange and co-precipitation (PO43− involvement) were validated more contributive than chemisorption (CaCO3 and CaSO4 involvement). As a feasible, reusable, and eco-friendly technique, SC suggests promising applications in the treatment of fluoride-contaminated groundwater.

Maduramicin (Mad), a polyether ionophore antibiotic, has been reported to be toxic to animals and humans because of being used at high doses or for long time, resulting in heart failure. However, the toxic mechanism of Mad in cardiac muscle cells is not well understood. Here, we show that Mad induced cell viability reduction and apoptosis in cardiac-derived H9c2, HL-1 cells, primary cardiomyocytes, and murine cardiac muscles, which was because of the inhibition of extracellular-signal-regulated kinase 1/2 (Erk1/2). Expression of constitutively active mitogen-activated protein kinase kinase 1 (MKK1) attenuated Mad-induced cell death in H9c2 cells, whereas silencing Erk1/2 or ectopic expression of dominant negative MKK1 strengthened Mad-induced cell death. Moreover, we found that both phosphatase and tensin homolog on chromosome 10 (PTEN) and protein kinase B (Akt) were implicated in the regulation of Erk1/2 inactivation and apoptosis in the cells and tissues exposed to Mad. Overexpression of dominant negative PTEN and/or constitutively active Akt, or constitutively active Akt and/or constitutively active MKK1 rescued the cells from Mad-induced dephosphorylated-Erk1/2 and cell death. Furthermore, Mad-induced reactive oxygen species (ROS) activated PTEN and inactivated Akt-Erk1/2 contributing to cell death, as N-acetyl- L-cysteine ameliorated the event. Taken together, the results disclose that Mad inhibits Erk1/2 via ROS-dependent activation of PTEN and inactivation of Akt, leading to cell death in cardiac muscle cells. Our findings suggest that manipulation of the ROS-PTEN-Akt-Erk1/2 pathway may be a potential approach to prevent Mad-induced cardiotoxicity.

In this study, SnO composites with incorporated nanodiamonds (NDs) were synthesized by a simple ultrasonic reaction method using SnCl2 and NH4HCO3 as raw materials. Results showed that the SnO/ND composites comprised SnO, SnO2, and diamond. High-resolution transmission electron microscopy (HRTEM) results indicated that a tight-contact interface formed between the SnO nanosheets and NDs. All SnO/ND composites exhibited a high efficiency for degrading methyl orange (MO) under visible light. The optimum degradation rate of MO was obtained for SnO/9.2% ND composite (98%) and SnO (16.6%) sample after 45 min of visible-light irradiation.

Resveratrol, a natural polyphenol compound, has been shown to possess anticancer activity. However, how resveratrol inhibits cancer cell adhesion has not been fully elucidated. Here, we show that resveratrol suppressed the basal or type I insulin-like growth factor (IGF)-1-stimulated adhesion of cancer cells (Rh1, Rh30, HT29, and HeLa cells) by inhibiting the extracellular signal-regulated kinase 1/2 (Erk1/2) pathway. Inhibition of Erk1/2 with U0126, knockdown of Erk1/2, or overexpression of dominant-negative mitogen-activated protein kinase kinase 1 (MKK1) strengthened resveratrol's inhibition of the basal or IGF-1-stimulated of Erk1/2 phosphorylation and cell adhesion, whereas ectopic expression of constitutively active MKK1 attenuated the inhibitory effects of resveratrol. Further research revealed that both protein phosphatase 2A (PP2A) and phosphatase and tensin homolog (PTEN)-Akt were implicated in resveratrol-inactivated Erk1/2-dependent cell adhesion. Inhibition of PP2A with okadaic acid or overexpression of dominant-negative PP2A rendered resistance to resveratrol's suppression of the basal or IGF-1-stimulated phospho-Erk1/2 and cell adhesion, whereas expression of wild-type PP2A enhanced resveratrol's inhibitory effects. Overexpression of wild-type PTEN or dominant-negative Akt or inhibition of Akt with Akt inhibitor X strengthened resveratrol's inhibition of the basal or IGF-1-stimulated Erk1/2 phosphorylation and cell adhesion. Furthermore, inhibition of mechanistic/mammalian target of rapamycin (mTOR) with rapamycin or silencing mTOR enhanced resveratrol's inhibitory effects on the basal and IGF-1-induced inhibition of PP2A-PTEN, activation of Akt-Erk1/2, and cell adhesion. The results indicate that resveratrol inhibits Erk1/2-mediated adhesion of cancer cells via activating PP2A-PTEN signaling network. Our data highlight that resveratrol has a great potential in the prevention of cancer cell adhesion.

SnO/SnO2 composites were synthesised through a simple solid-phase grinding-assisted ultrasonic reaction by using SnCl2 and NH4HCO3 as raw materials. Results showed that SnCl2 reacted with NH4HCO3 to form Sn6O4(OH)4 and NH4Cl through solid-phase grinding. Sn6O4(OH)4 was subsequently hydrolysed to SnO nanosheets. A small amount of SnO grains was transformed to SnO2. Different treatment processes played important roles in the composition, microstructural morphology and photocatalytic activity of SnO/SnO2 composites. The direct ultrasonication of ground products yielded microspheres comprising numerous SnO nanosheets and SnO2 nanoparticles with excellent visible photocatalytic properties, which can degrade 93.5% of methyl orange within 75 min.

As a kind of tropical agricultural solid waste, cassava dregs had become a thorny nonpoint source pollution problem. This study investigated the feasibility of applying cassava dregs as a substitute for sucrose in biofloc technology (BFT) systems. Three types of biofloc systems (using three different carbon sources sucrose (BFT1), cassava dregs (BFT2) and enzyme-hydrolyzed cassava dregs (BFT3) respectively), and the control were constructed in this experiment in 200L tanks with a C/N ratio of 20/1. The comparison of the water quality indicators (The total ammonia nitrogen (TAN), nitrite (NO2--N), nitrate (NO3--N), chemical oxygen demand (COD)), biofloc for the above four groups was performed, and the results indicated that BFT3 showed greater potential to the formation of biofloc, which was beneficial for the water quality control. So the shrimp survival rate was the highest and the feed conversion rate was the lowest in BFT3. Besides, the high-throughput sequencing results showed that the relative abundance of heterotrophic bacteria in the top 30 dominant microbial communities in BFT3 was higher than those in BFT1 and BFT2 by 20.70% and 1.19%, respectively, which could decrease TAN to improve the water quality. Overall, the results had proved that the cassava dregs of enzymes hydrolysis could be used as an ideal and cheap carbon source in BFT.

Both antibiotics and sediments can affect the denitrification in aquatic systems. However, little is known how antibiotics influence the denitrification in the presence of sediments. Here, the effects of antibiotics (sulfamethoxazole, tetracycline and ofloxacin) on denitrification in the absence and presence of sediments were investigated. The influencing mechanisms were revealed by quantifying the denitrification functional genes (DNGs), 16S-seq of bacteria, and antibiotic resistance genes (ARGs). The results showed that the presence of antibiotics inhibited NO3-N reduction by decreasing the abundances of narG, nirK, nosZ, total DNGs, and denitrifying bacteria. However, the inhibition effect was alleviated by sediments, which promoted the growth of bacteria and decreased the selective pressure of antibiotics as the vector of bacteria and antibiotics, thus increasing the abundances of denitrifying bacteria and all the DNGs. Partial least-squares path model disclosed that antibiotics had negative effects on bacteria, ARGs and DNGs, while sediments had negative effects on ARGs but positive effects on bacteria and DNGs. The network analysis further revealed the close relation of the genera Bacillus, Acinetobacter, and Enterobacter with the ARGs and DNGs. The findings are helpful to understand the denitrification in antibiotic-polluted natural waters.

The irrational NH3 emission routinely poses a significant threat to human health and environmental protection even at low dose. In addition, high miniaturization and low power-consumption has been the critical requirements of Internet of Things. To meet these demands, it is greatly pressing to develop a novel gas sensor with the capability to detect trace NH3 without external heating or light-irradiation elements. In this work, the organic conducting conjugated polymer PEDOT:PSS was combined with inorganic nitrogen-doped transition metal carbides and nitrides (N-MXene Ti3C2T x ) for chemiresistive NH3 sensing at room temperature (20 oC). By means of the organic–inorganic n–p heterojunctions via the synergistic effect, the results show that the composite film sensor with the optimal mass ratio of 1:0.5 between N-MXene and PEDOT:PSS components delivered favorable NH3 sensing performance than individual N-MXene or PEDOT:PSS counterparts in terms of higher response and quicker response/recovery speeds under 20 oC@36%RH air. Besides, decent repeatability, stability and selectivity were demonstrated. The incorporated N atoms served as excellent electron donors to promote the electron-transfer reactions and augment the sorption sites. Simultaneously, partial oxidation of MXene brought about some TiO2 nanoparticles which acted as spacers to widen the interlayer spacing and probably suppress the MXene restacking during the film deposition, thus favoring the gas diffusion/penetration within the sensing layer and then a quick reaction kinetic. The modulation of consequent build-in field within the heterojunctions was responsible for the reversible NH3 sensing. In addition, pre-adsorbed water molecules facilitated to establish a swift adsorption/desorption balance. The proposed strategy expanded the application range of MXene based composite materials and enrich the current sensing mechanisms of NH3 gas sensors.

Mineral carbonation of fly ash can both capture and store CO2 permanently in a single process without long-term monitoring. Previous studies indicate that fly ash with high calcium and magnesium contents exhibit promising CO2 fixation capability. However, the reaction mechanisms and kinetics involved in the carbonation reaction of fly ash is still not fully understood. In this study, a typical Victorian brown coal fly ash from Hazelwood power plant was selected to sequestrate CO2 in a direct aqueous carbonation process. Experiments were conducted in a vessel reactor at various temperatures (40, 50, 60, and 70 °C), stirring rates (900, 1050, 1200, and 1350 rpm), and CO2 pressures (3, 4, 5, 6, and 7 bar) to investigate the reaction kinetics and identify the rate-limiting steps of carbonation. The results show that both the carbonation rate and the maximum carbonation efficiency could be improved by optimizing parameters and by the introduction of NaHCO3. Also, the complex effects of the operating parameters...

The contamination profiles of sixteen perfluoroalkyl substances (PFAS) were examined in coral reef fish samples collected from the South China Sea (SCS) where no information about this topic was available in the literature. The results revealed that six PFAS were found in coral reef fish samples from the SCS. Perfluorooctane sulfonate (PFOS) was the most predominant PFAS contaminant detected in most of the samples, with the highest concentration value of 27.05 ng/g wet weight (ww) observed in Cephalopholis urodelus. Perfluoroundecanoic acid (PFUnDA) and Perfluorotridecanoic acid (PFTrDA) were the second and third dominant PFAS, respectively. Mean PFOS concentrations in muscle of seven coral reef fish varied from 0.29 ng/g ww in Lethrinus olivaceus to 10.78 ng/g ww in Cephalopholis urodelus. No significant linear relationship was observed between PFOS levels and coral reef fish traits (length, weight) collected in this region. Average daily intake of PFOS for the seven coral reef fishes ranged from 0.79 ng/kg/d for Lethrinus olivaceus to 29.53 ng/kg/d for Cephalopholis urodelus. The hazard ratio (HR) values for human consumption of PFOS-contaminated coral reef fishes ranged from 0.04 to 1.48, with Cephalopholis urodelus having the highest HR value of 1.18 (higher than 1) among the species, indicating frequent consumption of Cephalopholis urodelus might pose potential health risk to local population. The present work have provided the first hand data of PFAS in coral reef fishes in the SCS and indirectly demonstrated the existence of low level PFAS pollution in the SCS in China.

A batch fluidized bed reactor (BFBR) with modified biosynthetic crystals (MBC), derived from Pseudomonas sp. HXF1, was investigated for the treatment of the groundwater containing fluoride (F-). Impacts of different hydraulic retention time (HRT), pH, and initial F- concentration on F- removal were examined and the maximum defluorination efficiency was recorded as 95.20%. Moreover, recycling experiments were performed to evaluate the stability of repeated use. BFBR/MBC system showed a long-term effective treatment outcome with low fluctuation in the concentrations of residual Ca2+ and F-. The formed precipitates were characterized by SEM, XPS, XRD, and FTIR. The defluorination mechanisms of BFBR/MBC system were defined as the chemisorption and induced crystallization of Ca5(PO4)3F on the MBC surface. As a feasible, economical, and environment-friendly technique, the method has a long-term value, which suggests promising applications in F- removal and resourceful treatment.

Transition metal boride enable applications in fields of cutting tools as the hard phase, but their fabrication suffers from shortcomings in high temperature for binary and hard/soft phase balance. Here, we leveraged a WCoB-Co cermets prepared by using elemental powders of W, Co and B powders via in situ synthesis method and investigated the microstructure evolution of a composite structure of WCoB/Co. The phase evolution, microstructure evolution and mechanical properties were investigated using X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The complete sintering process consist of three solid-phase reaction stages and one liquid-phase sintering stage. The solid-phase reaction stage includes the following three reactions: B + 2Co → Co2B, 11 W +15 Co2B → 9WCoB + W2Co21B6, and 14 W + 2W2Co21B6 → 12WCoB + 23Co + Co7W6. The eutectic liquid phase, essential for the densification, forms at 1323 °C. The Rockwell hardness and density value reach 87.5HRA and 12.11 g/cm3, respectively. At 1380 °C, the traverse rupture strength (TRS) reaches the peak value of 1495 MPa. Moreover, the results show that transgranular fracture is the main fracture mode. The densification stage was completed at ~1400 °C. In particular, Co7W6 phase was discovered during the study of the evolution of WCoB-Co cermets. An increase of the B content was found to be beneficial to eliminate the Co7W6 phase that proved to be detrimental to mechanical properties.

The pearlite-to-austenite transformation during isothermal and uniform heating processes of classic bearing steels was studied using a dilatometer. The relationship between ferrite, cementite, and austenite during the transformation was investigated in detail. To explain the experimental phenomenon more theoretically, pearlite-to-austenite transformation was simulated using the DICTRA module of the Thermo-Calc software package based on a simplified model. Experimental results validated the pearlite-to-austenite transformation mechanism of low-alloy steel previously proposed. The transformation is controlled by Cr diffusion and C diffusion below and above the partition-to-no-partition temperature, respectively.

Chlorination disinfection and antibiotic addition are two universal processes of marine culture. The generation of disinfection byproducts (DBPs) is unavoidable. Antibiotic residue not only pollutes water but also acts as a precursor to the production of new DBPs. The fate of antibiotic norfloxacin (NOR) in chlorination disinfection was investigated. It was observed that NOR could be oxidized by disinfection agent sodium hypochlorite, but the oxidation rate varied considerably with the type of disinfected water. For fresh water, marine culture water and sea water, the reaction rate constant was 0.066 min −1 , 0.466 min −1 and 1.241 min −1 , respectively. The difference was primarily attributed to the promotion role of bromide ions in seawater and marine culture water. Moreover, the bromide ions could result in the generation of brominated DBPs (Br-DBPs). The kinetics, products, reaction centers and mechanisms were investigated. The active site of NOR was found to be the N4 atom on piperazinyl in fresh water. During marine culture water and sea water disinfection, the carboxyl on NOR was oxidized and two Br-DBPs were formed. This was attributed to the lowering of the reaction's required activation energy when performed in the presence of bromide ions. The Br-DBPs were also confirmed in real shrimp pond brackish water. Quantitative structure activity relationships and the total organic halogen analysis showed that the DBPs in marine culture water possessed stronger toxicological properties than the DBPs in fresh water. The toxicity increase was attributed to the production of Br-DBPs in the disinfection process of marine culture water.

Unexpected reduction of iminoquinone (IQ) and quinone derivatives was first reported during positive electrospray ionization mass spectrometry. Upon increasing spray voltage, the intensities of IQ and quinone derivatives decreased drastically, accompanying the increase of the intensities of the reduction products, amodiaquine (AQ) and phenol derivatives. To gain more insight into the mechanism of such reduction, we explored the experimental factors that are influential to corona discharge (CD). The results show that experimental parameters that favor severe CD, including metal spray emitter, using water as spray solvent, sheath gas with low dielectric strength (e.g., nitrogen), and shorter spray tip-to-mass spectrometer inlet distance, facilitated the reduction of IQ and quinone derivatives, implying that the reduction should be closely related to CD in the gas phase. Graphical Abstract ᅟ.

Tuber formation of potato is a complex biological process and is regulated by many factors including phytochrome, hormones, transcription factors, RNAs, microRNAs, etc. In our previous study, CYP707A1, an ABA 8′-hydroxylase gene, was down-regulated in the StCOL antisense transgenic potato stolons, but its relation with potato tuberization has not been studied yet. In this study, to investigate the role of this gene in potato tuberization, we cloned a CYP707A1 gene from potato cultivar Desiree and constructed the StCYP707A1 over-expression and anti-sense potato lines by Agrobacterium-mediated transformation. In total, four over-expression transgenic lines and nine anti-sense transgenic lines were confirmed by PCR analysis. Semi-quantitative RT-PCR and qRT-PCR analysis showed that the level of StCYP707A1 transcripts was significantly higher in the over-expression lines (A7 and A9) and lower in the anti-sense lines (F2 and F8), compared to the wild-type control. We further analyzed tuber formation in the transgenic lines and the wild-type control. The result showed that tuber yield per plant and average tuber weight were decreased in A7 and A9 and increased in F2. We also measured the content of ABA and GA3 in transgenic lines. ABA level was reduced in A7 and A9 and increased in F2. Contrariwise, the concentration of GA3 was higher in A7 and A9, and lower in F2 than in wild-type control. These results indicate that StCYP707A1 negatively affects potato tuberization through ABA regulation on gibberellic acid concentration.

The goal of this study is to experimentally assess the role of vertical sinking and degradation processes of persistent organic pollutants (POPs) in a subtropical water column. This was done by measuring the concentrations of selected typical organochlorine pesticides, including hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB), dichlorodiphenyltrichloroethanes (DDTs), trans-chlordane (TC), and cis-chlordane (CC), in atmosphere (gas phase), water (dissolved and particulate phases), and sedimentation samples simultaneously from October 2011 to April 2013 in a subtropical lake. The fugacity ratios suggested net deposition for α-HCH, γ-HCH, p,p'-DDT, p,p'-DDD, p,p'-DDE, o,p'-DDT, TC, and CC, indicating that the subtropical lake was acting as a "sink" for these chemicals. The enantiomer fractions of α-HCH, o,p'-DDT, TC, and CC in the dissolved phase samples were much more deviated from the racemic values than were those in the air samples, suggesting that these chemicals have suffered microbial degradation in the subtropical lake. In fact, 99% to 100% of atmospheric input of α-HCH and γ-HCH to the subtropical lake was estimated to be depleted via microbial degradation, while the role of hydrolysis and vertical sinking was very small. For more hydrophobic p,p'-DDT, o,p'-DDT, TC, and CC, the role of vertical sinking was 2 to 3 orders of magnitude larger than that for α-HCH and γ-HCH. Microbial degradation was also very important for removing p,p'-DDT, o,p'-DDT, TC, and CC from the water column.