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Background Collagen peptides (CP) have been shown to protect against osteoporosis. Yet, its mechanism on anti-osteoporosis remains unclear. Method Cell viability, levels of alkaline phosphatase (ALP), reactive oxygen species (ROS), malondialdehyde (MDA) and superoxide dismutase (SOD) of hydrogen peroxide (H2O2)-induced oxidative stress in Saos-2 cells pretreated with CP were examined. The effect and regulatory of CP on FBXW7-p100-NF-κB axis and the relationship between the molecules were explored by overexpressing FBXW7, silencing p100 or NF-κB in Saos-2 cells. Western blot and RT-PCR were performed to determine the expressions of FBXW7, p100 and NF-κB. Hematoxylin & Eosin (H&E) staining was performed to determine morphological indexes of bone tissues in ovariectomized-induced osteoporosis rats treated with CP. Result CP increased cell viability, ALP and antioxidant activities in H2O2-induced oxidative stress in Saos-2 cells. Results on cell viability, ALP, antioxidant levels, protein and gene expression levels in FBXW7-overexpressed, p100-silenced and NF-κB-silenced Saos-2 cells indicate that FBXW7, p100 and NF-κB are the key regulators and CP treatment modulates FBXW7-p100-NF-κB axis in Saos-2 cells. In addition, pretreatment and treatment with CP in ovariectomized rats improved osteoporosis. Conclusion CP could effectively prevent and alleviate osteoporosis. The protective effect of CP on osteoporosis was achieved in part by inhibiting oxidative damage of osteoblasts and promoting bone formation.

In this paper direct electrochemistry and electrocatalysis of myoglobin (Mb) immobilized on a graphene (GR)–SnO2 nanocomposite modified carbon ionic liquid electrode was reported. GR–SnO2 nanocomposite was synthesized by a simple solution method and further characterized by TEM and SEM, which exhibited large surface area beneficial for Mb immobilization. Spectroscopic results indicated Mb retained its native structure without denaturation after mixed with nanocomposite. Electrochemical investigation showed that a pair of well-defined redox peaks appeared on cyclic voltammogram, indicating that direct electron transfer of Mb with the underlying electrode was realized. The results could be attributed to the presence of GR–SnO2 nanocomposite that could enhance the electron transfer between the protein and the electrode. The Mb modified electrode exhibited good stability and catalytic activity to the electroreduction of NaNO2 in the concentration range from 0.2 to 350.0 μmol L−1 with wider dynamic range and lower detection limit. Therefore the fabricated electrode has the potential application in the third-generation electrochemical biosensor. Keywords: Carbon ionic liquid electrode, Direct electrochemistry, Graphene, Myoglobin, SnO2

An ionic liquid catalyzed Friedel–Crafts alkylation reaction of substituted benzenes with CCl4 was developed. The reaction proceeded efficiently under mild conditions, gave corresponding trichloromethylarenes with diversity functional groups in moderate to good yields. The influence of Lewis acidity of ionic liquids on the conversion of the alkylation reaction has been investigated. Notably, the probable mechanism of this reaction has been proposed with the assistance of 27Al NMR spectroscopy. It was noteworthy that the predominance of [Al2Cl7]− species in EmimCl–AlCl3, N = 0.67 could be detected by 27Al NMR spectral analysis, and [AlCl4]− was generated at the beginning of reaction. Additionally, it was found that [AlCl4]− could be transformed into [Al2Cl7]− when the reaction finished. Some control experiments confirmed that the interaction between Lewis acidic species [Al2Cl7]− of the ionic liquid and CCl4 led to the change in speciation of aluminum during the alkylation reactions.

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The 17β-hydroxysteroid dehydrogenase type 3 (17β-HSD3) enzyme is a potential therapeutic target for hormone-dependent prostate cancer, as it is the key enzyme in the last step of testosterone (T) biosynthesis. A curcumin analog, H10, was optimized for inhibiting T production in LC540 cells that stably overexpressed 17β-HSD3 enzyme (LC540 [17β-HSD3]) (P < 0.01), without affecting progesterone (P) synthesis. H10 downregulated the production of T in the microsomal fraction of rat testes containing the 17β-HSD3 enzyme from 100 to 78.41 ± 7.41%, 51.86 ± 10.03%, and 45.14 ± 8.49% at doses of 10, 20, and 40 μM, respectively. There were no significant differences among the groups with respect to the protein expression levels of 17β-HSD3, 3βHSD1, CYP17a1, CYP11a1, and STAR, which participate in 17β-HSD3-mediated conversion of androgens to T (P > 0.05). This indicated that H10 only inhibited the enzymatic activity of 17β-HSD3 in vitro. Furthermore, H10 inhibited the adione-stimulated growth of xenografts established from LNCaP cells in nude mice in vivo. We conclude that H10 could serve as an effective inhibitor of 17β-HSD3, which in turn would inhibit the biosynthesis of androgens and progression of prostate cancer.

Akkermansia muciniphila can produce various mucin-degrading proteins. However, the functional characteristics of these proteins and their role in mucin degradation are unclear. Of the predicted protein-coding genes, Amuc_1434, which encodes for a hypothetical protein, is the focus in this study. A recombinant enzyme Amuc_1434 containing the 6&times, His-tag produced in Escherichia coli (hereinafter termed Amuc_1434*) was isolated to homogeneity and biochemically characterised. Results showed that the enzyme can hydrolyse hemoglobin with an activity of 17.21 U/&mu, g. The optimal pH and temperature for hemoglobin hydrolysis of Amuc_1434* were found to be around 8.0 and 40 &deg, C, respectively. Amuc_1434* is identified as a member of the aspartic protease family through the action of inhibitor pepstatin A. Amuc_1434* promotes the adhesion of colon cancer cell line LS174T, which can highly express Muc2. Significantly Amuc_1434* can degrade Muc2 of colon cancer cells. Amuc_1434 is mainly located in the colon of BALB/c mice. These results suggest that the presence of Amuc_1434 from Akkermansia muciniphila may be correlated with the restoration of gut barrier function by decreasing mucus layer thickness.

Ethanol and toluene are important organic solvents in chemical industry. Ethanol, toluene and water present a ternary minimum-boiling azeotrope and three binary azeotropes. In this article, two methods are studied to separate the ternary azeotrope: heterogeneous azeotropic distillation using the toluene, which is in the system itself, as entrainer and extractive distillation with glycerol as the only one solvent. In the heterogeneous azeotropic distillation, the pressures of the three columns are changed respectively to achieve heat integration. In the extractive distillation, only one solvent and two columns are used to separate the ternary mixture. Experiment shows that the partially heat-integrated heterogeneous azeotropic distillation reduces the energy cost and total annual cost by 27.7% and 13.4% respectively compared with the conventional heterogeneous azeotropic distillation. Unexpectedly, the extractive distillation can save 18.8% and 39.3% in the energy cost and total annual cost respectively compared with the partially heat-integrated heterogeneous azeotropic distillation.

Browning generation always limits the application of protein-carbohydrate conjugates. In the present study, we found that ultrahigh pressure can promote bovine serum albumin (BSA)-glucose conjugation without browning generation. BSA-glucose conjugates were fabricated at 120, 240 and 360 MPa for 4 h. The intermediate products, browning intensity, glucose concentration and secondary structure of conjugates were tested. Results suggested that BSA-glucose conjugates were generated at pressures of 240 and 360 MPa with significant increase of absorbance at 294 nm (Abs294) from 0.88 to 0.93 and 1.17, and marked consumption of glucose to 87 and 85%. While, insignificant change was found in browning (Abs420) or the secondary structure of BSA during conjugates formation with 40–42% α-helix, 5–10% β-sheet and 21–23% β-turns. Near no BSA-glucose conjugates were formed at lower pressure of 120 MPa. This study indicated that ultrahigh pressure is a potential method to generate colorless BSA-glucose conjugates. Industrial Relevance The color generation is a serious problem limiting the industrial application of protein-carbohydrate conjugates. There is nearly no report about inhibiting the color formation during fabricating protein-carbohydrate conjugates. Our study suggested an effective method to fabricate colorless BSA-glucose conjugates, which may provide potential improvement in food processing.

As one of the potential candidates for electrocatalysis, non-precious transition metal and nitrogen co-doped graphene has attracted extensive attention in recent years. A deep understanding of the oxygen reduction reaction (ORR) mechanism including the specific active sites and reaction pathways will contribute to the further enhancement of the catalytic activity. In this study, the reaction mechanism for ORR on Fe–N3 doped graphene (Fe–N3-Gra) is investigated theoretically. Our results show that Fe–N3-Gra is thermodynamically stable. The ORR elementary reactions take place within a small region around the Fe–N3 moiety and its adjacent six C atoms. HOOH does not exist on the catalyst surface, indicating a direct four-electron process for Fe–N3-Gra. The kinetically most favorable pathway is O2 hydrogenation, in which the formation of the second H2O is the rate-determining step with an energy barrier of 0.87 eV. This value is close to 0.80 eV for pure Pt, suggesting that Fe–N3-Gra could be a potential electrocatalyst. Free energy changes at different electrode potentials are also discussed.

The purpose of this study was to investigate the antiatherosclerosis effects of ursolic acid (UA) in high-fat diet-fed quails (Coturnix coturnix) and potential mechanism. Quails were treated with high-fat diet (14 % pork oil, 1 % cholesterol w/w) with or without UA (50, 150, or 300 mg/kg/day) for 10 weeks. Serum lipid profile was assessed at 0, 4.5, and 10 weeks. After 10 weeks, serum antioxidant status and morphology of aorta were assessed. Additionally, human umbilical vein endothelial cells (HUVECs) were exposed to 100 μg/ml oxidized low-density lipoprotein (ox-LDL) for 24 h, with or without pretreatment with UA (5, 10 or 20 μM) for 16 h, autophagy inhibitor 3-MA 5 mM for 2 h, or SIRT1 inhibitor EX-527 10 μM for 2 h. Cell viability and oxidative stress status were assessed and autophagy status was determined. Acetylation of lysine residue on Atg5 was assessed with immunoprecipitation. In results, high-fat diet negatively affected serum lipid profile and antioxidant status in quails and induced significant histological changes. Cotreatment with UA remarkably alleviated such changes. In HUVECs, ox-LDL treatment induced significant cytotoxicity along with oxidative stress, while UA cotreatment alleviated such changes significantly. UA treatment induced autophagy, enhanced SIRT1 expression, and decreased acetylation of lysine residue on Atg5. Cotreatment with 3-MA or EX-527 effectively abolished UA's protective effects. In summary, UA exerted antiatherosclerosis effects in quails and protected HUVECs from ox-LDL induced cytotoxicity, and the mechanism is associated with increased SIRT1 expression, decreased Atg5 acetylation on lysine residue, and increased autophagy.

A multilayers of graphene (GR) and myoglobin (Mb) modified electrode was fabricated with a layer of chitosan film. Electrochemical behaviors of the modified electrode were studied by cyclic voltammetry, which exhibited a couple of well-behaved, stable and quasi-reversible cathodic and anodic peaks, indicating that Mb realized its direct electron transfer on the biosensor. The experimental result may be accredited to the existence of multilayers conductive GR nanosheets that could provide big specific surface area, fine biological compatibility and ultrahigh electron transfer route for the immobilized Mb. The catalytic reduction peak currents of the biosensor to the detection of trichloroacetic acid were established from 0.6 to 26.0 mM accompanied with the detection limit as 0.15 mM (3σ). Therefore a novel third-generation mediator-free electrochemical sensor was successful prepared with the usage of multilayers of GR.

The oxygen reduction reaction (ORR) and carbon dioxide reduction reaction (CO2RR) have attracted worldwide attention in order to solve the energy crisis and global warming. In this work, we have investigated the ORR and CO2RR activity of Fe-porphyrin carbon material (FeN4-C) by using the density functional method. The catalytic active sites are identified based on the charge transfer analysis and it is found that FeN4 moiety and its adjacent eight C atoms are the active centre. ORR proceeds via a four-electron process. The OOH hydrogenation into O + H2O is the most favourable pathway with the rate-determining step to be the formation of OOH. The energy barrier is 0.09 eV, much smaller than 0.56 eV for FeN4 doped graphene and 0.80 eV for pure Pt. The predicted working potential is 0.52 V, larger than 0.35 V for FeN4 doped graphene. For CO2RR, CO2 tends to be reduced to HCHO and CH3OH with the limiting potential of −0.62 V. HCOOH is the minor product. In a word, the above results suggested that FeN4-C is a promising bifunctional electrocatalyst for both ORR and CO2RR.

In this paper three-dimensional graphene (3D-GR) was directly formed on the surface of carbon ionic liquid electrode (CILE) by electrodeposition. By using 3D-GR/CILE as the substrate electrode, a new electrochemical biosensor was prepared by immobilization of hemoglobin (Hb) on the electrode surface with a chitosan film. Electrochemical investigation indicated that a pair of well-defined redox peaks appeared on cyclic voltammogram, indicating the realization of direct electron transfer of Hb with the underlying electrode. The result can be ascribed to the porous structure of 3D-GR with high conductivity and big surface area. Based on the electrochemical data, the electron transfer coefficient ( α ) and the apparent heterogeneous electron transfer rate constant ( k s ) were calculated to be 0.426 and 1.864 s −1 , respectively. The modified electrode displayed good electrocatalytic activity to the reduction of trichloroacetic acid (TCA), and the catalytic reduction peak current had a good linear relationship to TCA concentration in the range from 0.4 to 26.0 mmol/L with the detection limit of 0.133 mmol/L (3 σ ). Therefore a new third-generation electrochemical Hb biosensor based on 3D-GR/CILE was constructed with good stability and reproducibility.

In this article, a carbon ionic liquid electrode (CILE) was fabricated by using ionic liquid N-hexylpyridinium hexafluorophosphate as the binder and the modifier. Then urchinlike MnO2 microsphere and chitosan (CTS) was further casted on the CILE surface step-by-step to get a modified electrode that was denoted as CTS/MnO2/CILE. Cyclic voltammetric studies indicated that bisphenol A (BPA) exhibited a well-defined oxidation peak at 0.486 V in 22.83 g L−1 pH 8.0 Britton‒Robinson buffer solution, which was attributed to the electro-oxidation of BPA on the modified electrode. The presence of urchinlike MnO2 microsphere on the electrode surface could increase the oxidation peak current (Ipa) greatly, which may be due to the larger surface area that could adsorb more BPA on the electrode surface. Electrochemical parameters of BPA on the modified electrode were calculated with the electron transfer coefficient (α) as 0.66 and the apparent heterogeneous electron transfer rate constant (ks) as 0.50 s−1. Under the o...

In this paper a Mg2Al-Cl layered double hydroxide (Mg2Al-LDH) modified carbon ionic liquid electrode (CILE) was prepared and further used for the electrochemical detection of rutin. Cyclic voltammograms of rutin on Mg2Al-LDH/CILE were recorded with a pair of well-defined redox peaks appeared in pH 2.5 phosphate buffer solution, which was ascribed to the electrochemical reaction of rutin. Due to the presence of Mg2Al-LDH on the electrode surface, the redox peak currents increased greatly and the electrochemical parameters were calculated. Under the optimal conditions the oxidation peak current was proportional to rutin concentration in the range from 0.08 μmol L-1 to 800.0 μmol L-1 with the detection limit on 0.0255 μmol L-1 (3σ). The fabricated electrode showed good reproducibility and stability, which was successfully applied to rutin tablet samples determination.

Titanium dioxide (TiO2) nanowires were synthesized and used for the realization of direct electrochemistry of hemoglobin (Hb) with carbon ionic liquid electrode (CILE) as the substrate electrode. TiO2-Hb composite was casted on the surface of CILE with a chitosan film and spectroscopic results confirmed that Hb retained its native structure in the composite. Direct electron transfer of Hb on the modified electrode was realized with a pair of quasi-reversible redox waves appeared, indicating that the presence of TiO2 nanowires could accelerate the electron transfer rate between the electroactive center of Hb and the substrate electrode. Electrochemical behaviors of Hb on the modified electrode were carefully investigated with the values of the electron transfer coefficient (α), the electron transfer number and the heterogeneous electron transfer rate constant (ks) as 0.58, 0.98 and 1.62 s-1. The Hb modified electrode showed excellent electrocatalytic activity to the reduction of trichloroacetic acid and NaNO2 with wider linear range and lower detection limit, indicating the successful fabrication of a new third-generation biosensor.

In this paper, zirconia (ZrO2) and graphene (GR) nanocomposite was electrodeposited on the surface of carbon ionic liquid electrode (CILE), which was used to construct an electrochemical DNA biosensor. GR was electroreduced from graphene oxide by potentiostatic method, and ZrO2 nanoparticle was further electrodeposited on GR/CILE by cycling voltammetric scan in a ZrOCl2 solution. The presence of GR on the electrode surface can provide a highly conductive interface with large surface area for the loading of ZrO2 nanoparticles. Single-stranded DNA (ssDNA) probe sequences with phosphate group at the 5′ end could be easily immobilized on the surface of ZrO2/GR/CILE due to the strong affinity between ZrO2 and phosphate groups. The ssDNA/ZrO2/GR/CILE was applied to hybridize with the target ssDNA sequence, and methylene blue (MB) was used as the electrochemical indicator. Due to the different binding models of MB with double-stranded DNA and ssDNA on the electrode surface, electrochemical response of MB was decreased after the hybridization reaction. Under the optimal conditions, the reduction peak current of MB was proportional to the concentration of Staphylococcus aureus nuc gene sequence in the range from 1.0 × 10−13 to 1.0 × 10−6 mol L−1 with the detection limit of 3.23 × 10−14 mol L−1 (3σ). The electrochemical DNA sensor exhibited good selectivity to various mismatched ssDNA sequences, and the polymerase chain reaction amplification products of S. aureus nuc gene sequence were further detected with satisfactory results. Therefore, this electrochemical DNA sensor with ZrO2 nanoparticles and GR nanosheet modified electrode could be used for the detection of specific ssDNA sequence in real biological samples.

A carbon ionic liquid electrode (CILE) was constructed by using ionic liquid 1-butyl-3-meth-ylimidazolium dihydrogen phosphate, (BMIM)H2PO4, as modifier and further employed as a novel working electrode for the determination of guanosine-5′-monophosphate (GMP). The study of electrochemical behavior of GMP on the CILE showed a single well-defined irreversible oxidation peak on the cyclic voltammogram. Under the selected conditions the oxidation peak current was proportional to GMP concentration in the range from 5.0 to 1000 μM with the limit of detection of 1.3 μM (3σ) by differential pulse voltammetry. The proposed method showed good selectivity to the GMP detection without the interferences of coexisting substances.

In this paper a novel electrochemical sensor was fabricated for the sensitive detection of dopamine (DA). By using a carbon ionic liquid electrode (CILE) as the substrate electrode, graphene (GR), gold nanoparticles (AuNPs) and double-stranded deoxyribonucleic acid (dsDNA) were electrodeposited on the surface of CILE step-by-step to obtain the modified electrode (dsDNA/Au/GR/CILE). Due to the presence of various modifiers on the electrode surface, the modified electrode exhibited specific synergistic effects, such as high conductivity and large surface of GR, good conductivity and biocompatibility of AuNPs, and the specific binding effect of dsDNA with the target analyte DA. Cyclic voltammetric studies indicated that a pair of well-defined redox peaks of DA appeared on dsDNA/Au/GR/CILE in pH 6.0 phosphate buffer solution and electrochemical behaviors of DA were carefully investigated. Under the optimal conditions the oxidation peak current of DA was linearly related to DA concentration in the range from 0.04 μmol L−1 to 0.6 mmol L−1 with a detection limit of 19.0 nmol L−1 (3σ). The modified electrode displayed excellent selectivity and repeatability, and was further used to detect DA content in drug samples with satisfactory results.

Salinity significantly limits leaf photosynthesis but the photosynthetic limiting factors in salt- stressed leaves remain unclear. In the present work, photosynthetic and biochemical traits were investigated in four rice genotypes under two NaCl (0 and 150 mM) concentration to assess the stomatal, mesophyll and biochemical contributions to reduced photosynthetic rate (A) in salt stressed leaves. Our results indicated that salinity led to a decrease in A, leaf osmotic potential, electron transport rate and CO2 concentrations in the chloroplasts (Cc) of rice leaves. Decreased A in salt-stressed leaves was mainly attributable to low Cc, which was determined by stomatal and mesophyll conductance. The increased stomatal limitation was mainly related to the low leaf osmotic potential caused by soil salinity. However, the increased mesophyll limitation in salt stressed leaves was related to both osmotic stress and ion stress. These findings highlight the importance of considering mesophyll conductance when developing salinity-tolerant rice cultivars.AbbreviationsAphotosynthetic rateCc, CO2concentration at carboxylation sitesCEapparent Rubisco activityChltotal chlorophyll contentCiintercellular CO2 concentrationETRelectron transport rateF0initial fluorescence of photosystem II in darknessFmmaximum fluorescence of photosystem IIFvmaximum variable fluorescence of photosystem IIFv/Fmmaximum quantum efficiency of photosystem IIgmmesophyll conductiongsstomatal conductionJmaxmaximum electron transport rateKleaf K contentLMAleaf mass per areaNleaf N contentPleaf P contentOPosmotic potentialProteinleaf total soluble protein contentqNnon-chemical quenching efficiencyRdday respirationRdarkdark respirationRubiscoRubisco contentVcmaxmaximum carboxylation rateαleaf light absorptance efficiencyβthe distribution of electrons between PSI and PSIIΓ*CO2 compensation point in the absence of respirationΦPSIIquantum efficiency of photosystem II.

Perfluorooctanoic acid (PFOA) is an environmental contaminant that could induce developmental cardiotoxicity in a chicken embryo, which may be alleviated by l-carnitine. To explore the roles of reactive oxygen species (ROS) and nitric oxide (NO) in such changes and the potential effects of l-carnitine, fertile chicken eggs were exposed to PFOA via an air cell injection, with or without l-carnitine co-treatment. The ROS and NO levels in chicken embryo hearts were determined with electron spin resonance (ESR), and the protein levels of the nuclear factor κ-light chain-enhancer of activated B cells (NF-κB) p65 and inducible nitric oxide synthase (iNOS) in chicken embryo hearts were assessed with western blotting. The results of ESR indicated that PFOA exposure induced an elevation in the ROS levels in ED19 chicken embryo hearts and hatchling chicken hearts, while l-carnitine could alleviate such changes. Meanwhile, increased NO levels were observed in ED19 embryo hearts and hatchling hearts following PFOA exposure, while l-carnitine co-treatment exerted modulatory effects. Western blotting revealed that p65 translocation in ED19 embryo hearts and hatchling hearts was enhanced by PFOA, while l-carnitine co-treatment alleviated such changes. iNOS expression levels in ED19 embryo hearts followed the same pattern as NO levels, while a suppression of expression was observed in hatchling hearts exposed to PFOA. ROS/NF-κB p65 and iNOS/NO seem to be involved in the late stage (ED19 and post hatch) of PFOA-induced developmental cardiotoxicity in a chicken embryo. l-carnitine could exert anti-oxidant and NO modulatory effects in the developing chicken embryo hearts, which likely contribute to its cardioprotective effects.

By using ionic liquid 1-hexylpyridinium hexafluorophosphate based carbon ionic liquid electrode (CILE) as the substrate electrode, graphene (GR) and nickel oxide (NiO) were in situ electrodeposited step by step to get a NiO/GR nanocomposite modified CILE. Myoglobin (Mb) was further immobilized on the surface of NiO/GR/CILE with a Nafion film to get the electrochemical sensor denoted as Nafion/Mb/NiO/GR/CILE. Cyclic voltammetric experiments indicated that a pair of well-defined quasi-reversible redox peaks appeared in pH 3.0 phosphate buffer solution with the formal peak potential (E0′) located at − 0.188 V (vs. SCE), which was the typical characteristics of Mb Fe(III)/Fe(II) redox couples. So the direct electron transfer of Mb was realized and promoted due to the presence of the NiO/GR nanocomposite on the electrode. Based on the cyclic voltammetric data, the electrochemical parameters of Mb on the modified electrode were calculated. The Mb modified electrode showed an excellent electrocatalytic activity towards the reduction of different substrates including trichloroacetic acid and H2O2. Therefore a third-generation electrochemical Mb biosensor based on NiO/GR/CILE was constructed with good stability and reproducibility.

Nitrogen-doped graphene (NG) was synthesized and used for the investigation on direct electrochemistry of hemoglobin (Hb) with a carbon ionic liquid electrode as the substrate electrode. Due to specific characteristics of NG such as excellent electrocatalytic property and large surface area, direct electron transfer of Hb was realized with enhanced electrochemical responses appearing. Electrochemical behaviors of Hb on the NG modified electrode were carefully investigated with the electrochemical parameters calculated. The Hb modified electrode exhibited excellent electrocatalytic reduction activity toward different substrates, such as trichloroacetic acid and H2O2, with wider dynamic range and lower detection limit. These findings show that NG can be used for the preparation of chemically modified electrodes with improved performance and has potential applications in electrochemical sensing.

Heat stress causes morphological and physiological changes and reduces crop yield in rice (Oryza sativa). To investigate changes in phytohormones and their relationships with yield and other attributes under heat stress, four rice varieties (Nagina22, Huanghuazhan, Liangyoupeijiu, and Shanyou 63) were grown in pots and subjected to three high temperature treatments plus control in temperature-controlled greenhouses for 15 d during the early reproductive phase. Yield reductions in Nagina22, Huanghuazhan, and Liangyoupeijiu were attributed to reductions in spikelet fertility, spikelets per panicle, and grain weight. The adverse effects of high temperature were alleviated by application of exogenous 6-benzylaminopurine (6-BA) in the heat-susceptible Liangyoupeijiu. High temperature stress reduced active cytokinins, gibberellin A1 (GA1), and indole-3-acetic acid (IAA), but increased abscisic acid (ABA) and bound cytokinins in young panicles. Correlation analyses and application of exogenous 6-BA revealed that high temperature-induced cytokinin changes may regulate yield components by modulating the differentiation and degradation of branches and spikelets, panicle exsertion, pollen vigor, anther dehiscence, and grain size. Heat-tolerant Shanyou 63 displayed minor changes in phytohormones, panicle formation, and grain yield under high temperature compared with those of the other three varieties. These results suggest that phytohormone changes are closely associated with yield formation, and a small reduction or stability in phytohormone content is required to avoid large yield losses under heat stress.

Cytokinins (CTKs) regulate panicle size and mediate heat tolerance in crops. To investigate the effect of high temperature on panicle CTK expression and the role of such expression in panicle differentiation in rice, four rice varieties (Nagina22, N22; Huanghuazhan, HHZ; Liangyoupeijiu, LYPJ; and Shanyou63, SY63) were grown under normal conditions and subjected to three high temperature treatments and one control treatment in temperature-controlled greenhouses for 15 days during the early reproductive stage. The high temperature treatments significantly reduced panicle CTK abundance in heat-susceptible LYPJ, HHZ, and N22 varieties, which showed fewer spikelets per panicle in comparison with control plants. Exogenous 6-benzylaminopurine application mitigated the effect of heat injury on the number of spikelets per panicle. The high temperature treatments significantly decreased the xylem sap flow rate and CTK transportation rate, but enhanced cytokinin oxidase/dehydrogenase (CKX) activity in heat-susceptible varieties. In comparison with the heat-susceptible varieties, heat-tolerant variety SY63 showed less reduction in panicle CTK abundance, an enhanced xylem sap flow rate, an improved CTK transport rate, and stable CKX activity under the high temperature treatments. Enzymes involved in CTK synthesis (isopentenyltransferase, LONELY GUY, and cytochrome P450 monooxygenase) were inhibited by the high temperature treatments. Heat-induced changes in CTK transportation from root to shoot through xylem sap flow and panicle CTK degradation via CKX were closely associated with the effects of heat on panicle CTK abundance and panicle size. Heat-tolerant variety SY63 showed stable panicle size under the high temperature treatments because of enhanced transport of root-derived CTKs and stable panicle CKX activity. Our results provide insight into rice heat tolerance that will facilitate the development of rice varieties with tolerance to high temperature.

By using the hydrothermal method, carbon microspheres (CMS) were fabricated and used for electrode modification. The characteristics of CMS were investigated using various techniques. The biocompatible sensing platform was built by immobilizing hemoglobin (Hb) on the micrometer-sized CMS-modified electrode with a layer of chitosan membrane. On the cyclic voltammogram, a couple of quasi-reversible cathodic and anodic peaks appeared, showing that direct electrochemistry of Hb with the working electrode was achieved. The catalytic reduction peak currents of the bioelectrode to trichloroacetic acid was established in the linear range of 2.0~70.0 mmol·L(-1) accompanied by a detection limit of 0.30 mmol·L(-1) (3σ). The modified electrode displayed favorable sensitivity, good reproducibility and stability, which suggests that CMS is promising for fabricating third-generation bioelectrochemical sensors.

Waveguides with low propagation losses were written in erbium-doped silicate glasses by tightly focused femtosecond laser pulses. Raman spectra measurements and 2-D refractive index mapping in the micro-areas near the focus were carried out. The results supported that the refractive index change induced by fs laser pulses comes from the increase of the low rank ring structures in the silicate network.

The second-order nonlinearities in thermally poled lead borate glasses were studied. After poling with different electrodes, both bulk and near surface second-order nonlinearities were obtained. The second harmonic generation signal from near surface effect was two orders of magnitude larger than the bulk effect. By simulating the poling process with a multiple carrier model, we concluded that the bulk second-order nonlinearity was caused by the deficiency of Pb2+ in a thick layer after poling, and the near surface second-order nonlinearity was caused by the depletion of H+ in a thin layer when H+ injection from the atmosphere was blocked.

Ferroelectricity in Langmuir–Blodgett (LB) films (Z-type and alternated Y-type) of nitrogencrown (NC) and arachidic acid (AA) was investigated by electric polarization measurements and small angle X-ray diffraction (SAXD). For Z-type AA LB multilayer and the AA LB films incorporating barium ions, as well as for Z-type NC LB multilayer and the Y-type NC/AA alternating LB films, hysteresis loops of the samples were observed and confirmed existence of the remnant polarizations in the LB films. Their corresponding remnant polarizations were found to be 15, 180, 450 and 9400 μC m −2 , respectively. Therefore, the maximum ratios of remnant polarizations up to 620 (9400/15)-folds were obtained from NC/AA alternating LB films. The enhancement of ferroelectricity in NC/AA alternating LB films was observed for the first time. It was demonstrated that the enhancement of ferroelectricity in the LB films could be created by incorporation of barium ions into the LB film structures and strong interaction due to electron clouds redistribution largely originated from the compact insertion configuration of AA between two chains of NC molecules in interleaving films.

Pyroelectric properties in alternating hemicyanine (DAEP)/nitrogencrown (NC) Langmuir–Blodgett (LB) films and effects of incorporating barium cations on pyroelectric behaviors have been investigated. Its pyroelectric coefficient measured is found to be 58 μC m−2 K−1at 300 K. Their dielectric properties have been measured and used to determine the figures of merit in thermal devices. Relative permittivity (ɛr) and dielectric loss values (tan δ) of pyroelectric films (in the range of 1–100 KHz) are found to be 2.34–1.96 and 0.08–0.04, respectively. These data give a maximum pyroelectric figure of merit of 150 μC m−2 K−1 in the alternating LB films incorporating barium ions. The effects of different deposition on pyroelectric properties are also discussed in this paper.

We have investigated on cyanine dye (HQ) in Langmuir–Blodgett (LB) films by spectroscopic ellipsometer (SE) and compared the results with that obtained by using small angle X-ray diffraction (SAXD). It is found from the isotherms that there is a critical point on Langmuir films near the area 0.8 nm 2 /molecule for HQ LB films with and without Cd 2+ ions, respectively and suggested that the facts should result from the phase transition due to the change of molecular tilt angle on surface of sub-phase. The refractive indexes as a function of the wavelength λ are reported by the SE method using the three layers-model (air-LB film-silicon wafer) and Cauchy dispersion equation, for the first time presented in literature. The thickness of a single deposited layer is 2.45 nm on average. The thickness of per monolayer is agreement with those obtained by SAXD measurements.

The cyano and nitro groups were chosen as acceptor groups, and the substituent amino or ether groups as donor groups to the matrix. Polyurethane (PU) was modified by glycerol to increase the content of chromophore and to improve the stability of the nonlinearity. T g and T m were raised and solubility, film-forming ability and other physical properties were improved. The average functional groups of the reactant can be adjusted to ≥ 2 with polygroups and monogroups mixture. These poled polymers show high second-order optical nonlinearity and would have potential application in frequency-doubling or electro-optical controlling devices.

A systematic investigation and comparison of the photoluminescence (PL) quantum yields of six erbium(III) organic complexes are reported. We demonstrated that the PL quantum yield could be significantly improved by getting rid of OH and CH groups in the complexes. Moreover, perfluooctanoic acid with neither OH nor CH groups was used as a ligand to form complex with Er3+. The quantum yield of the newly synthesized erbium(III) complex was found to be as high as 2%, 100 times higher than ever reported.

Photo-induced trans – cis isomerization and orientation of cyano-substituted 4′- N , N -dimethylamino-nitrosilbene (DANS) and phenylhydrazone derivatives doped polymer films have been studied. Comparing with DANS, these molecules show large photo-induced optical anisotropy (POA) due to the addition of cyano-group onto C C or C N bond which makes these molecules be much more easily photoisomerized. The mechanism of POA can be understood well by the current theories. Qualitative and quantitative explanations were given based on the trans – cis quantum yield, absorption spectrum, cis – trans relaxation, interaction with the host polymer, and the molecular structure.

Hyper Rayleigh scattering (HRS) and other measurements were carried out to investigate the solubilization of 4-dimethylamino-4′-nitro-azobenzene (DNAB) particles by sodium dodecyl sulfate (SDS) micelles. DNAB is hardly soluble in water and forms micrometer-size particles consisting of H-aggregates. HRS results show that these particles have very small second order optical nonlinearity. For partly solubilized particles, the breaking of H-aggregates on particle surface results in very large HRS intensities. At large SDS concentration, most of the particles are dissolved into monomers that are adsorbed on the outer-layer of the SDS micelles. HRS also reveals that Ostwald ripening process can recover the ‘destroyed’ particle surface.

The negative refractive index changes were obtained in lead silicate glasses with different lead concentrations (from 30 mol% PbO to 50 mol% PbO) by irradiation with the frequency-quadrupled output of a Q-switched YAG laser (266 nm, 10 Hz repetition rate) at low energy density (50 mJ/cm 2 ). The largest refractive index change Δ n was −0.25 ± 0.04 in lead silicate glasses with 50 mol% PbO. UV-visible absorption spectra of the lead silicate glass with 43 mol% PbO were measured after exposure to the 266 nm laser beams with energy density from 50 mJ/cm 2 to 350 mJ/cm 2 . The absorption coefficients in visible wavelength increased suddenly when the energy density of the laser beam was larger than a threshold value. This showed that the structural changes of lead silicate glasses were different after exposure to the 266 nm laser beam with different energy densities.

We found that, although alpha'-cyano-4'-nitro-4-N, N-dimethylaminostilbene has larger hyperpolarizability than that of conventional 4'-N, N-dimethylamino-nitrostilbene, the addition of the cyano group makes it much more easy to photo-isomerize, thus destroying the molecular ordering in poled chromophore doped polymers. Experimental evidence was obtained by monitoring the second-harmonic generation intensity, UV–Vis absorption spectrum, and FTIR spectrum. The photo-isomerization reaction process was monitored by optical pump induced absorption anisotropy measurement. Comparisons with the behaviour of a azobenzene dye are also made.

Laser induced darkening in the soda-lime silicate (15Na 2 O · 15CaO · 70SiO 2 ) based glass and type N 31 barium metaphosphate Ba(PO 3 ) 2 based glass were studied by exposing the glass samples in frequency-quadrupled Nd:YAG (266 nm, 5 ns) laser and Ti:Sapphire (800 nm, 120 fs) laser. Both types of the glasses were doped with Nd 2 O 3 at doping levels less than 3 wt%. Hole center HC 1 formed after UV laser exposure in soda-lime silicate based laser glass, and both HC 1 hole center and SiE ′ center formed in it after IR fs laser irradiation. In phosphate glass, UV ns laser and IR fs laser generated the same types of color centers, intermediate structure of oxygen ions type II and type III. The experimental results also showed that the soda-lime silicate laser glass is easier to be darkened than the phosphate glass, irradiated by either 266 nm UV laser or fs laser. While free electrons from single photon ionization is considered to be the main cause of defect formation in glasses irradiated by nanosecond UV laser, rapid cooling of the melted glasses heated by energetic electrons generated from multi-photon and avalanche ionization should be the causes of defect formation in glasses irradiated by fs laser.

Monolithic Er-doped silica xerogels with erbium content of 5000 ppm were prepared by sol-gel technique. Samples were densified by thermal treatment in O2/CCl4 environment. The 1.55 μm photoluminescence lifetimes after annealing at different temperatures were measured, together with the relative content of hydroxyl groups inside the samples. It was found that hydroxyl groups can be removed by CCl4 effectively. Consequently the photoluminescence lifetime of the samples increased significantly after the removal of hydroxyl groups. For sample treated in O2/CCl4 at 900°C, fluorescence lifetime as long as 6ms was obtained and is pretty stable when the sample is kept in ambient air.

Ferroelectricity in Langmuir-Blodgett (LB) films (Z-type and alternated Y-type) of nitrogencrown (NC) and arachidic acid (AA) was investigated by electric polarization measurements and surface pressure-molecular area π(π-A) isotherm. For Z-type AA LB multilayer and the AA LB films incorporating barium and manganese ions, as well as for Z-type NC LB multilayer and the Y-type NC/AA alternating LB films, typical hysteresis loops of the samples were observed and confirmed existence of the remnant polarizations in the LB films. Their corresponding remnant polarizations were found to be 15, 180, 650, 450 and 9400 μC · m−2, respectively. Therefore, it was demonstrated that the enhancement of ferroelectricity in the LB films could be created by incorporation of barium and manganese ions into the LB film structures and strong interaction between alternating monolayers of the samples. These novel approaches can be employed to create strong ferroelectric LB films to make ferroelectric thin-film device for practical applications.

UV–visible absorption spectra of binary lead silicate glasses with different lead concentrations were measured after irradiation with the frequency-quadrupled output of a Q-switched YAG laser (266 nm, 10 Hz repetition rate). Two different changes of absorption spectra after exposure to laser beams with different energy densities were observed. This implied that the formation of defects in lead silicate glasses was connected to the UV beam energy density.

Two series of novel rod-like compounds containing Schiff-base and naphthalimide units were synthesized. The liquid crystalline and amorphous phases of these compounds have been studied by differential scanning calorimetry (DSC), polarizing microscopy and X-ray diffraction. It was found that compounds 1A, 2A and 3A with a bridge of benzene show an amorphous glassy state, whereas compounds 1B, 2B and 3B with 2,5-dioctyloxy-1,4-bis(phenylenevinylene)benzene as a bridge exhibit smectic F and nematic mesomorphic phases. These rod-like compounds emit yellow–green light with the photoluminescent peak at about 505 nm and have relatively high quantum yields. The nonlinear optical properties of the compounds have been investigated by using a second harmonic generation (SHG) technique on a Langmuir–Blodgett monolayer. Compound 3B exhibits SHG properties with a susceptibility χ(2) of about 1.51 × 10−9 esu.

In recent years, chemical liver injury cases increased significantly in Asian countries, and the imbalance in redox system was believed to be the main cause. Purple sweet potato anthocyanins (PSPA) have been shown to exert antioxidant activity and oxidative-stress-associated functional protein modulation through various signaling pathways, so it is considered to have the potential of liver injury preventive activity. In order to evaluate the hepatoprotective potency of PSPA according to its free radical scavenging and antioxidant effects, three acute chemical liver injury models were set up with ethanol, acetaminophen and carbon tetrachloride. PSPA at moderate and high doses obviously attenuated the tested serum biomarker levels and liver index in our experiments. Besides, one chronic liver injury model set up with carbon tetrachloride was also applied, in which PSPA was orally administrated after the liver damage had been formed. Both the serum biomarker levels and histopathological analysis showed that PSPA was able to attenuated chronic liver injury. Our experimental results demonstrated the potential of PSPA as an oral hepatoprotective agent against chemical liver injury from food plant.

Influence of the interlayer interactions on aggregates in Langmuir-Blodgett films has been investigated by using the steady-state and time-resolved fluorescence techniques.