Cloning and characterisation of a Δ9 fatty acyl desaturase-like gene from the red claw crayfish (Cherax quadricarinatus) and its expression analysis under cold stress.

Desaturase is one of the key enzymes in the unsaturated fatty acid synthesis pathway. Δ9 desaturase catalyzes the synthesis of oleic acid from stearic acid by introducing double bonds in the 9th and 10th carbon chains, thereby increasing the content of MUFAs in the body. In order to explore the main function of the Δ9 desaturase gene under low temperature stress, RACE-PCR technology was used in this study to clone the full-length sequence of the CqFAD9-like from the hepatopancreas of red claw crayfish, Cherax quadricarinatus. The full length of the sequence is 1236 bp, and the open reading frame is 1041 bp, encoding 346 amino acid residues. The 5 'UTR is 116 bp, the 3' UTR is 79 bp, and the 3 'UTR contains a PloyA tail. The predicted theoretical isoelectric point and molecular weight are 8.68 and 40.28 kDa, respectively. Homology analysis showed that the sequence had the highest similarity with FAD9 from crustaceans. The results of real-time PCR showed that the expression level of this gene was highest in the hepatopancreas, which was significantly higher than other tissues, followed by the ovaries, brain ganglion and stomach. At the same time, the expression of the CqFAD9-like in hepatopancreas of crayfish cultured at 25, 20, 15 and 9 °C for four weeks was detected. The results showed that expression of the FAD9 gene increased gradually with decreasing temperature, indicating that metabolic desaturation might play a regulatory role during cold stress.

The marine-derived furanone reduces intracellular lipid accumulation in vitro by targeting LXRα and PPARα.

Recent studies have demonstrated that commercially available lipid-lowering drugs cause various side effects; therefore, searching for anti-hyperlipidaemic compounds with lower toxicity is a research hotspot. This study was designed to investigate whether the marine-derived compound, 5-hydroxy-3-methoxy-5-methyl-4-butylfuran-2(5H)-one, has an anti-hyperlipidaemic activity, and the potential underlying mechanism in vitro. Results showed that the furanone had weaker cytotoxicity compared to positive control drugs. In RAW 264.7 cells, the furanone significantly lowered ox-LDL-induced lipid accumulation (~50%), and its triglyceride (TG)-lowering effect was greater than that of liver X receptor (LXR) agonist T0901317. In addition, it significantly elevated the protein levels of peroxisome proliferator-activated receptors (PPARα) and ATP-binding cassette (ABC) transporters, which could be partially inhibited by LXR antagonists, GSK2033 and SR9243. In HepG2 cells, it significantly decreased oleic acid-induced lipid accumulation, enhanced the protein levels of low-density lipoprotein receptor (LDLR), ABCG5, ABCG8 and PPARα, and reduced the expression of sterol regulatory element-binding protein 2 (~32%). PPARα antagonists, GW6471 and MK886, could significantly inhibit the furanone-induced lipid-lowering effect. Furthermore, the furanone showed a significantly lower activity on the activation of the expression of lipogenic genes compared to T0901317. Taken together, the furanone exhibited a weak cytotoxicity but had powerful TC- and TG-lowering effects most likely through targeting LXRα and PPARα, respectively. These findings indicate that the furanone has a potential application for the treatment of dyslipidaemia.

Boosting the Open Circuit Voltage and Fill Factor of QDSSCs Using Hierarchically Assembled ITO@Cu2S Nanowire Array Counter Electrodes.

The key challenges in enhancing the power conversion efficiency (PCE) of a quantum dot-sensitized solar cell (QDSSC) are efficiently achieving charge separation at the photoanode and improving the charge transfer, which is limited by the interface between the electrolyte and the counter electrode (CE). Here, hierarchically assembled ITO@Cu2S nanowire arrays with conductive single-crystalline ITO cores and Cu2S nanocrystal shells were designed as efficient QDSSCs CEs. These arrays not only provided an efficient three-dimensional charge transport network but also allowed for the effective deposition of more Cu2S nanocrystals as active sites to catalyze the electrolyte reaction. This design considerably reduced the sheet and charge transfer resistance of the CE, thus decreasing the series resistance and increasing the shunt resistance of the QDSSC. As a result, QDSSCs with this CE exhibited an unprecedentedly high Voc of 0.688 V, a fill factor of 58.39%, and a PCE of 6.12%, which is 21.2% higher than that of the conventional brass/Cu2S CE.

ITO@Cu2S tunnel junction nanowire arrays as efficient counter electrode for quantum-dot-sensitized solar cells.

Quantum-dot-sensitized solar cell (QDSSC) has been considered as an alternative to new generation photovoltaics, but it still presents very low power conversion efficiency. Besides the continuous effort on improving photoanodes and electrolytes, the focused investigation on charge transfer at interfaces and the rational design for counter electrodes (CEs) are recently receiving much attention. Herein, core-shell nanowire arrays with tin-doped indium oxide (ITO) nanowire core and Cu2S nanocrystal shell (ITO@Cu2S) were dedicatedly designed and fabricated as new efficient CEs for QDSSCs in order to improve charge collection and transport and to avoid the intrinsic issue of copper dissolution in popular and most efficient Cu/Cu2S CEs. The high-quality tunnel junctions formed between n-type ITO nanowires and p-type Cu2S nanocrystals led to the considerable decrease in sheet resistance and charge transfer resistance and thus facilitated the electron transport during the operation of QDSSCs. The three-dimensional structure of nanowire arrays provided high surface area for more active catalytic sites and easy accessibility for an electrolyte. As a result, the power conversion efficiency of QDSSCs with the designed ITO@Cu2S CEs increased by 84.5 and 33.5% compared to that with planar Au and Cu2S CEs, respectively.

α-Fe2 O3 nanodisks: layered structure, growth mechanism, and enhanced photocatalytic property.

Layered structure: α-Fe2 O3 nanodisks with a layered structure assembled from nanoplates were produced by a hydrothermal method. The simple, low-cost method used silicate anions as capping ligands, which selectively adsorbed onto the {0001} facet of α-Fe2 O3 and terminated the growth along the [0001] direction, leading to platelike building units. The layered structure led to significantly enhanced absorption of visible light, compared with single-layer α-Fe2 O3 , and excellent photocatalytic abilities.

Temperature-responsive smart nanoreactors: poly(N-isopropylacrylamide)-coated Au@mesoporous-SiO2 hollow nanospheres.

A nanoreactor with temperature-responsive poly(N-isopopylacrylamide) (PNIPAM) coated on the external pore mouth of mesoporous silica hollow spheres and Au nanoparticles at the internal pore mouth were fabricated. Such spatial separation allows both Au nanoparticles and PNIPAM to function without interfering with each other. Transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectra, and temperature-dependent optical transmittance curves demonstrate successful grafting of PNIPAM. This nanoreactor shows repeated on/off catalytic activity switched by temperature control. It shows excellent catalytic activity toward 4-nitrophenol (4-NP) reduction at 30 °C [below lower critical solution temperature (LCST) of PNIPAM] with a turnover frequency (TOF) of 14.8 h(-1). However, when the temperature was 50 °C (above LCST), the TOF dropped to 2.4 h(-1). Kinetic studies indicated that diffusion into the mesopores of the catalyst was the key factor, and the temperature-responsive behavior of PNIPAM was able to control this diffusion.

Low-cost synthesis of flowerlike α-Fe2O3 nanostructures for heavy metal ion removal: adsorption property and mechanism.

Flowerlike α-Fe(2)O(3) nanostructures were synthesized via a template-free microwave-assisted solvothermal method. All chemicals used were low-cost compounds and environmentally benign. These flowerlike α-Fe(2)O(3) nanostructures had high surface area and abundant hydroxyl on their surface. When tested as an adsorbent for arsenic and chromium removal, the flowerlike α-Fe(2)O(3) nanostructures showed excellent adsorption properties. The adsorption mechanism for As(V) and Cr(VI) onto flowerlike α-Fe(2)O(3) nanostructures was elucidated by X-ray photoelectron spectroscopy and synchrotron-based X-ray absorption near edge structure analysis. The results suggested that ion exchange between surface hydroxyl groups and As(V) or Cr(VI) species was accounted for by the adsorption. With maximum capacities of 51 and 30 mg g(-1) for As(V) and Cr(VI), respectively, these low-cost flowerlike α-Fe(2)O(3) nanostructures are an attractive adsorbent for the removal of As(V) and Cr(VI) from water.

Effect of HMGB1 silencing on cell proliferation, invasion and apoptosis of MGC-803 gastric cancer cells.

High-mobility group box 1 (HMGB1) is a multifunctional protein with intranuclear and extracellular functions. Although HMGB1 is overexpressed in approximately 85% of gastric cancers, the role of HMGB1 in gastric cancer biology remains unclear. In this study, we investigate the effect of downregulation of HMGB1 on the biological behavior of gastric cancer cells. MGC-803 gastric cancer cells were transduced with HMGB1-specific RNAi lentiviral vectors. Real-time polymerase chain reaction and Western blot analysis of HMGB1 mRNA and protein, respectively, validated the silencing effects. HMGB1-specific silencing significantly decreased cell proliferation. The impact on proliferation was observed at the cell cycle level--the number of cells in the G0/G1 phase increased, whereas that in S and G2/M phases decreased. Cell cycle changes were accompanied by decreases in cyclin D1 expression. Furthermore, HMGB1 silencing sensitized cells to apoptosis that was induced by oxaliplatin and mediated by the caspase-3 pathway. Finally, silencing of HMGB1 expression significantly reduced cellular metastatic ability and MMP-9 expression in MGC-803 cells. In summary, HMGB1 not only plays an essential role in the proliferation and invasion of MGC-803 cells but also represents a potential target for the therapeutic intervention of gastric cancer.

Toxic effects and transcriptional responses in zebrafish liver cells following perfluorooctanoic acid exposure.

As a typical type of persistent organic pollutant, perfluorooctanoic acid (PFOA) is pervasive in the environment. Multiple studies have found that PFOA has hepatotoxicity, but the mechanism remains poorly understood. In this study, the toxic effects of different concentrations of PFOA on zebrafish liver cells were systematically assessed by recording cell survival, ultrastructural observations, and transcriptome analyses. The results showed that the inhibition of cell viability and the massive accumulation of autophagic vacuoles were observed at 400 µM PFOA, while transcriptomic changes occurred with treatments of 1 and 400 µM PFOA. The transcription levels of 1055 (977 up- and 78 down-regulated genes) and 520 (446 up- and 74 down-regulated genes) genes were significantly changed after treatment with 1 and 400 µM PFOA, respectively. Based on Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis, significant expression changes were observed in autophagy, tight junction, signal transduction, immune system, endocrine system, and metabolism-related pathways, indicating that such processes were greatly affected by PFOA exposure. The findings of this study will provide a scientific basis for the toxic effects and potential toxic mechanisms of PFOA on zebrafish, and provide information for ecological risk assessments.

Construction of covalent organic framework for catalysis: Pd/COF-LZU1 in Suzuki-Miyaura coupling reaction.

Covalent organic frameworks (COFs) are crystalline porous solids with well-defined two- or three-dimensional molecular structures. Although the structural regularity provides this new type of porous material with high potentials in catalysis, no example has been presented so far. Herein, we report the first application of a new COF material, COF-LZU1, for highly efficient catalysis. The easily prepared imine-linked COF-LZU1 possesses a two-dimensional eclipsed layered-sheet structure, making its incorporation with metal ions feasible. Via a simple post-treatment, a Pd(II)-containing COF, Pd/COF-LZU1, was accordingly synthesized, which showed excellent catalytic activity in catalyzing the Suzuki-Miyaura coupling reaction. The superior utility of Pd/COF-LZU1 in catalysis was elucidated by the broad scope of the reactants and the excellent yields (96-98%) of the reaction products, together with the high stability and easy recyclability of the catalyst. We expect that our approach will further boost research on designing and employing functional COF materials for catalysis.

Structural selection of graphene supramolecular assembly oriented by molecular conformation and alkyl chain.

Graphene molecules, hexafluorotribenzo[a,g,m]coronene with n-carbon alkyl chains (FTBC-Cn, n = 4, 6, 8, 12) and Janus-type "double-concave" conformation, are used to fabricate self-assembly on highly oriented pyrolytic graphite surface. The structural dependence of the self-assemblies with molecular conformation and alkyl chain is investigated by scanning tunneling microscopy and density functional theory calculation. An interesting reverse face "up-down" way is observed in FTBC-C4 assembly due to the existence of hydrogen bonds. With the increase of the alkyl chain length and consequently stronger van der Waals interaction, the molecules no longer take alternating "up-down" orientation in their self-assembly and organize into various adlayers with lamellar, hexagonal honeycomb, and pseudohoneycomb structures based on the balance between intermolecular and molecule-substrate interactions. The results demonstrate that the featured "double-concave" molecules are available block for designing graphene nanopattern. From the results of scanning tunneling spectroscopy measurement, it is found that the electronic property of the featured graphene molecules is preserved when they are adsorbed on solid surface.

[A cloud detection algorithm for MODIS images combining Kmeans clustering and multi-spectral threshold method].

An improved method for detecting cloud combining Kmeans clustering and the multi-spectral threshold approach is described. On the basis of landmark spectrum analysis, MODIS data is categorized into two major types initially by Kmeans method. The first class includes clouds, smoke and snow, and the second class includes vegetation, water and land. Then a multi-spectral threshold detection is applied to eliminate interference such as smoke and snow for the first class. The method is tested with MODIS data at different time under different underlying surface conditions. By visual method to test the performance of the algorithm, it was found that the algorithm can effectively detect smaller area of cloud pixels and exclude the interference of underlying surface, which provides a good foundation for the next fire detection approach.

Identification of the nitrogen species on N-doped graphene layers and Pt/NG composite catalyst for direct methanol fuel cell.

Heat treatment of graphene oxide (GO) with ammonia flow at various temperatures resulted in different distribution of nitrogen species. Synchrotron based X-ray absorption near-edge structure (XANES) spectroscopy provides unambiguous evidence for the presence of three nitrogen species. The Pt/NG-800 composite exhibits outstanding electrocatalytic activity for methanol oxidation.

[An improved method for forest fire spot detection based on variance between-class].

An improved method using variance between-class and smoke plume mask is described. The brightness temperature threshold of potential fire pixels was adjusted to be 305 K. Based on the variance between-class of TIR channel brightness temperature and a smoke plume detection algorithm, the improved algorithm can separate the hot fire spots from the background and seek out the cool fire spots, respectively, with suitable thresholds of variance between-class. This algorithm has been used in the forest fires that happened in Fujian province and Heilongjiang province. Study shows that detection results with the algorithm are more satisfactory. It is adapted in different environments and can be more accurately detected the high-temperature fire spot and the smoder at low temperature. It increases the ability and accuracy to detect fire spots.

Programmed fabrication of bimetallic nanobarcodes for miniature multiplexing bioanalysis.

Nanobarcodes with Morse code patterns are fabricated by a programmed electrochemical deposition process. These bimetallic nanobarcodes are stable and easy to decode using optical or electrical devices. Their discretionally patterned codes offer mass memory capacity for information carriers. They show promising features as probe molecules' carriers in multiplexing bioanalysis.

Facile synthesis of macrocellular mesoporous foamlike Ce-Sn mixed oxides with a nanocrystalline framework by using triblock copolymer as the single template.

Macrocellular mesoporous foamlike cerium-tin mixed oxide materials with well-defined porous structure and nanocrystalline frameworks are synthesized through a simple one-step self-assembly process using an amphiphilic triblock copolymer as the single template. The macrocellular pores are synthesized without the addition of any swelling agent or hazardous acids. The final mixed oxide possesses a hierarchically porous structure including macrocellular foam with ultralarge cell size, closed windows, and mesopores on the walls. This indicates that the porous structure can be notably stabilized and improved by the incorporation of Sn in the CeO(2). The materials are expected to be good candidates in catalysis, since the hierarchical porosity enables high surface areas and hence more chemically active sites associated with the mesopores, combined with the high efficiency of mass transport from the macrocellular foam. The catalytic characteristics are discussed in relation to the architectures of the materials, and it is revealed that the macrocellular/mesoporous materials would be an efficient catalyst for CO oxidation.

Silica nanotubes with mesoporous walls and various internal morphologies using hard/soft dual templates.

Silica nanotubes with mesoporous walls of 30 nm thickness and various internal morphologies are produced using hard/soft dual templates; this hierarchical pore structure shows faster mass transportation in catalysis.

Low-risk gestational trophoblastic neoplasia outcome after treatment with VMP regimen from 2005 to 2017.

OBJECTIVE: To evaluate the efficacy and toxicity of VMP regimen applied to the patients with low-risk gestational trophoblastic neoplasia (LR-GTN) treated in Anhui provincial hospital. MATERIALS AND METHODS: Between 2005 and 2017, 87 patients with low-risk gestational trophoblastic neoplasia received VMP regimen, consisted of vincristine (VCR), methotrexate (MTX) and platinum (cisplatin, carboplatin or nedaplatin), 68 of whom received VMP as their first-line chemotherapy, and 19 methotrexate-failed patients received VMP regimen as their second-line chemotherapy. The staging and scoring system was based on International Federation of Gynecology and Obstetrics (FIGO 2000) criteria. We describe and analyze their baseline characteristics, remission/resistance/recurrence rates, adverse reactions and prognosis. RESULTS: The first-line VMP protocol can achieve an 83.8% remission rate and it tended to develop resistance when the pretreatment ß-hCG reaches 7503.5 IU/L, and can achieve complete remission with FAV and EMA-CO as the salvage regimen. Among the 19 methotrexate-failed patients, 2 of whom were yet resistant to VMP regimen, followed by several courses of salvage chemotherapy such as FAV and EMP, and achieved 89.5% remission rate in second-line VMP group. Resistance to this regimen was obviously related with higher pre-treatment HCG whether used as primary or salvage treatment. Severe myelosuppression (grade 3 or 4) was shown in 4 (5.9%) of 68 cases, of which none was grade 4. CONCLUSION: For patients diagnosed with LR-GTN VMP regimen was a safe and effective treatment with a high rate of remission.

Facile synthesis of nanoporous anatase spheres and their environmental applications.

Highly nanoporous TiO(2) (anatase) spheres with an excellent ability in environmental applications have been successfully prepared via in situ hydrolysis of titanium glycolate precursor spheres.