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This study demonstrates the feasibility of applying La0.8Sr0.2MnO3 (LSM)-Ni oxide-metal composite to an interconnect layer for anode-supported solid oxide cells (SOCs) operated at 700 °C. The sintering behavior of LSM-Ni composites and the electrical properties of LSM-Ni composite in both reducing and oxidizing atmospheres were systematically examined. The densification and final microstructure of LSM-Ni composites are tailored by varying the size and content of Ni particles. A part of smaller Ni particles reacts with LSM matrix and forms a second phase, Sr-doped La2NiO4. The addition of Sr to La2NiO4 decreases the melting temperature of La2NiO4, which causes the liquid phase sintering and increases the density of the sintered of LSM-Ni composites. It is also found that LSM-Ni composites are electrically conductive, regardless of the atmosphere. In oxidizing atmospheres, LSM perovskite serves as the major conductive matrix. In reducing atmospheres, on the other hand, embedded Ni forms metallic percolation path and compensates for the decrease in the electrical conductivity of reduced LSM ceramics. This LSM-Ni is used to coat the multilayer thick film of LSM-Ni and LSM. The multilayer film exhibits higher and more stable electric conductivity than the single layer thick film of LSM in a simulated SOC operation environment. This shows that LSM-Ni composite can be a useful component of the interconnect of SOC, which maintains the good electric conductivity in both air and H2.

Background Previous studies demonstrated impaired lipid metabolism and augmented aerobic glycolysis in AF. The authors aimed to investigate whether the use of metformin, an AMPK activator, could reverse this metabolic remodeling in chronic AF and to explore the underlying mechanisms. Methods We conducted chronic AF animal models with 18 beagle dogs and divided them into SR (pacemaker implanted without pacing), AF (pacemaker implanted with sustained pacing at a frequency of 400 beats/min for 6 weeks), and metformin+AF group (daily oral administration of metformin was initiated 1 week before surgery and continued throughout the study period). After electrophysiological measurements, the left atrial appendage tissue samples were taken from the beating heart for further analysis. Protein expression, histological analysis, and biochemical measurements were conducted. Results The AF groups showed decreased expression of FAT/CD36, CPT-1, VLCAD, increased concentration of free fatty acid and triglyceride, and increased lipid deposition. The activation of AMPK/PGC-1α/PPARα pathway was decreased. The key factors of the Warburg effect, including HIF-1α, GLUT-1, PDK1, HK, and LDH, increased in AF group compared to SR group. The expression of PDH decreased significantly, accompanied by increased atrial lactate production. The extent of fibrosis increased significantly in the left atrial appendage of AF group. dERP, ∑WOV, and AF inducibility increased while ERP decreased in AF group compared to SR group. The use of metformin attenuated all these changes effectively. Conclusions Metformin improves lipid metabolism and reverses the Warburg effect in chronic AF via AMPK activation. It attenuates atrial electrical and structural remodeling.

Oxide red nanophosphors convert high-energy photons to red light and have potential applications in photonic devices, including fluorescent lamps, light-emitting devices, and biosensors. In this study, a series of OH–-substituted Sr5(PO4)3Cl:Eu3+ nanophosphors emitting red light were successfully synthesized via a microwave reaction method. The effects of OH– substitution on a change in the crystal structure and photoluminescence of Eu3+ in Sr5(PO4)3Cl1–xOHx were investigated. The ratio of Cl– to OH– ions was controlled by changing the Sr/Cl ratio in a precursor solution. Though some Cl– ions were substituted with OH– ions, the emission intensity ratio of the 5D0 → 7F2 transition to the 5D0 → 7F1 transition (I618/I593) did not change. This result indicated that Eu3+ ions preferentially occupy the MI site of an apatite structure in Sr5(PO4)3Cl and Sr5(PO4)3Cl1–xOHx. In addition, the intensity of the red emission from Sr5(PO4)3Cl1–xOHx:Eu3+ increased 4-fold as OH– replaced 20% of Cl–. Decay lifetime measure...

Background Ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) encodes the human plasma-cell membrane differentiation antigen-1, and ENPP1 variants have been shown to be associated with type 2 diabetes (T2D) and insulin resistance. In this study, we investigated the involvement of ENPP1 polymorphisms in T2D. Methods The association of the two polymorphisms of ENPP1 (rs7754586 and rs55725924) with T2D and diabetes-related quantitative traits was analyzed in Chinese samples containing 929 T2D patients and 1044 healthy individuals. We also performed the expression quantitative trait loci (eQTL) analysis to study the association of both polymorphisms of ENPP1 with mRNA expression levels using the genotype-tissue expression database. Results The risk allele A of the polymorphism rs7754586 contributed to T2D (odds ratio: 1.252, 95% confidence interval: 1.044–1.615, P = 0.018). The polymorphism rs55725924 was associated with the diastolic blood pressure and cholesterol levels. Patients carrying high-risk haplotype A-T of rs7754586 and rs55725924 exhibited a high risk of acquiring T2D. These associations were only observed in males, but not in females. In addition, the eQTL analysis demonstrated that the risk allele of rs7754586 was associated with higher levels of ENPP1 mRNA expression. Conclusion Our findings suggest that the ENPP1 polymorphism rs7754586 may implicate in the pathogenesis of T2D in men, while polymorphism rs55725924 may be involved in diastolic blood pressure and cholesterol of male T2D patients.

A trade-off between the carrier concentration and carrier mobility is an inherent problem of traditional transparent conducting oxide (TCO) films. In this study, we demonstrate that the electron concentration of TCO films can be increased without deteriorating the carrier mobility by embedding Ag nanoparticles (NPs) into Al-doped ZnO (AZO) films. An increment of Ag NP content up to 0.7 vol % in the AZO causes the electron concentration rising to 4 × 1020 cm–3. A dependence of the conductivity on temperature suggests that the energy barrier for the electron donation from Ag NPs at room temperature is similar to the Schottky barrier height at the Ag–AZO interface. In spite of an increase in the electron concentration, embedded Ag NPs do not compromise the carrier mobility at room temperature. This is evidence showing that this electron donation mechanism by Ag NPs is different from impurity doping, which produces both electrons and ionized scattering centers. Instead, an increase in the Fermi energy level o...

Background Atrial lipid metabolic remodeling is critical for the process of atrial fibrillation (AF). Abnormal Fatty acid (FA) metabolism in cardiomyocytes is involved in the pathogenesis of AF. MET (Metformin), an AMPK (AMP-activated protein kinase) activator, has been found to be associated with a decreased risk of AF in patients with type 2 diabetes. However, the specific mechanism remains unknown. Methods Fifteen mongrel dogs were divided into three groups: SR, ARP (pacing with 800 beats/min for 6 h), ARP plus MET (treated with MET (100 mg/kg/day) for two weeks before pacing). We assessed metabolic factors, speed limiting enzymes circulating biochemical metabolites (substrates and products), atrial electrophysiology and accumulation of lipid droplets. Results The expression of AMPK increased in the ARP group and significantly increased in the MET+ARP group comparing to the SR group. In the ARP group, the expressions of PPARα、PGC-1α and VLCAD were down-regulated, while the concentration of free fatty acid and triglyceride and the lipid deposition in LAA (left atrial appendage) increased. Moreover, AERP and AERPd have also been found abnormally in this process. Pretreatment with MET before receiving ARP reversed the alterations aforementioned. Conclusions The FA metabolism in LAA is altered in the ARP group, mainly characterized by the abnormal expression of the rate-limiting enzyme. Metformin reduces lipid accumulation and promotes β-oxidation of FA in AF models partially through AMPK/PPAR-α/VLCAD pathway. Our study indicates that MET may inhibit the FA lipid metabolic remodeling in AF.

Predictions of prospectivity based on remote sensing were developed using alteration mineral indicative hyperspectral mapping and remote sensing anomaly filtering, combined with geological characteristics and anomalous mineral field verification. Based on the results of the hyperspectral mineral mapping and the actual geological ground conditions, the results of mapping of altered minerals, such as chlorite, muscovite, kaolinite, and iron oxide were validated, and gold, silver, copper, nickel, and other geochemical anomaly areas were identified for verification work. The results of hyperspectral mineral extraction show that the mineral assemblage closely related to gold deposits in shear zones is muscovite + chlorite + epidote + kaolinite. This alteration mineral assemblage can be used as regional search criteria for shear zone gold mineralisation and was the basis for the discovery of mineralised hydrothermal alteration centres and delineation of four prospective targets. Established on a spectral prospectivity model of the study area, prospective ore-bearing areas have been delineated, which indicate the direction for further geological and mineral resource surveys.

Silver (Ag)-copper (Cu) bimetallic nanoparticles (NPs) were synthesized by the reduction of silver nitrate and copper (II) acetate monohydrate using ethylene glycol in a microwave (MW) heating system with controlled reaction times ranging from 5 min to 30 min. The molar ratio Ag/Cu was varied from 1:1 to 1:3. The effect of reaction conditions on the bimetallic NPs structures and compositions were characterized by x-ray photoelectron spectroscopy, x-ray diffraction and transmission electron microscopy. The average particle size was approximately 150 nm. The surface plasmon resonance (SPR) of Ag-Cu bimetallic NPs was investigated by monitoring the SPR band peak behavior via UV/Vis spectrophotometry. The resonance peak positions and peak widths varied due to the different structures of the bimetallic NPs created under the synthesis conditions. In the MW heating method, the reduction of Cu was increased and Cu was inhomogeneously deposited over the Ag cores. As the composition of Cu becoming higher in the Ag-Cu bimetallic NPs, the absorption between 400 nm to 600 nm was greatly enhanced.

We report the electrochemical properties of MnO2–NiO mixture layer that is coated on highly conductive SnO2 nanowires. In this study, the effect of the nanowire conductivity and coating composition on the pseudocapacitic performance was systematically examined. To control the electric conductivity of the nanowire, Sb was doped into SnO2 during vapor–liquid-solid (VLS) process. Subsequently, pure or NiO added MnO2 layer was electrochemically deposited on SnO2 nanowire arrays. Structural studies show that the electrodeposition layer uniformly and conformally covered the nanowires. Low concentration Sb doping (up to 5 at%) increases the electric conductivity of the nanowires which work as an electron transport layer of the pseudocapacitor. Electrochemical studies indicate that the addition of NiO to MnO2 promotes a charging/discharging process through Faraday reaction by changing the oxidation mechanism of MnO2. These results guide a design of the metal oxide mixture for the pseudocapacitor application.

SiC velvet cathode is applied to improve the performance of the L-band magnetically insulated line oscillator(MILO) 1–2. The SiC velvet is manufactured by electrostatic flocking technique which flocks the SiC fibers on a carbon blanket base. The SiC velvet is adhered on a stainless steel cathode to act as the emission material in the MILO tube. Comparative test were carried out between SiC velvet and polymer velvet in the same MILO tube. Current and microwave parameters without any sig-nificant differences between the two cathodes were detected. The plasma expansion velocity of SiC velvet is about 1.4 $\text{cm}/\mu\mathrm{s}$ which is calculated by impedance coupling method, while for polymer velvet the plasma expansion velocity is about $1.8 \text{cm}/\mu \mathrm{s}$ . SEM images show that no observable damage can be detected for the SiC fibers after several tens of shots. However, a small area of SiC fibers with dimensions of 3mmx3mm broke away from the carbon blanket base after several tens of shots which probably caused by poor binding strength between the SiC fibers and the carbon blanket. The SiC velvet shows comparable emission performance with polymer velvet. If the binding strength is enhanced the SiC velvet will be a preferred emission material for high power microwave tubes such as MILO.

Background Plasminogen activator inhibitor-1 (PAI-I), encoded by SERPINE1 gene, is a member of the serine protease inhibitor superfamily, and polymorphisms in SERPINE1 have been reported to be associated with type 2 diabetes (T2D). This study investigated whether the polymorphism in PAI-I contribute to the risk for T2D. Methods A 1:1 case-control study was conducted to investigate the association of rs6092 in SERPINE1 with T2D and diabetes-related metabolic traits, including body mass index, waist circumference (WC), triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol, low density lipoprotein cholesterol, fasting plasma glucose and glycosylated hemoglobin (HbA1c) in a Chinese population, with a total of 1572 subjects (786 T2D patients and 786 healthy controls). The polymorphism was genotyped based on MassARRAY genotyping system. Results The AA genotype and A allele of rs6092 exerted a protective effect on T2D risk (odds ratio (OR) = 0.431 and 0.630, respectively). In a recessive model, we also observed the protective association of rs6092 with T2D (OR = 0.195). The above associations were only observed in men. In female patients, there was a significant difference in HbA1c level between the AA homozygotes and GG homozygotes, as well as between the AA homozygotes and combined GG and GA genotypes. In male patients, the WC level in the subjects carrying AA genotype was lower than those in the subjects with GG genotype (P = 0.000), and the association was also significant in a recessive model (P = 0.000). Additionally, there was a significant difference in TG level between the AA homozygotes and GG homozygotes (P = 0.017), as well as the AA homozygotes and combined GG and GA genotypes (P = 0.032). Conclusions Our study suggests that the A allele and AA genotype of rs6092 may protect against T2D, and have a protective effect on WC, but a negative effect on TG in men, while may contribute to a lower HbA1c level in women.

Purpose: To explore the antihyperglycemic and antioxidant effects of Fructus Hordei Germinatus extract (FHGE) in diabetic rats.Methods: The aqueous extract of FHG was obtained by steeping the dried Fructus Hordei Germinatus in water at 60oC three times, each for 1 h before first drying in an oven and then freeze-drying the last extract thus obtained. Antihyperglycemic effect was measured by blood glucose and plasma insulin levels. Oxidative stress was evaluated in liver and kidney by antioxidant markers, viz, lipid peroxidation (LPO), superoxide dismutase (SOD), reduced glutathione (GSH), glutathione peroxidase (GPx) and catalase (CAT), while blood serum levels of creatinine and urea were also determined in both diabetic control and treated rats.Results: Compared with diabetic rats, oral administration of FHGE at a concentration of 20, 40 and 80 mg/kg daily for 45 days showed a significant decrease in fasting blood glucose (p < 0.05) and increased insulin (p < 0.05) level,. Furthermore, it significantly reduced biochemical parameters (serum creatinine and serum urea, p < 0.05)). The treatment also resulted in significant increase in GSH, GPx (p < 0.05), SOD and CAT (p < 0.05), as well as decreased LPO (p < 0.05) level in the liver and kidney of diabetic rats.Conclusion: The results suggest that FHGE may effectively normalize the impaired antioxidant status in streptozotocin-induced diabetes in a dose-dependent manner. FHGE has a protective effect against lipid peroxidation by scavenging free radicals and is thus capable of reducing the risk of diabetic complications.Keywords: Fructus hordei Germinatus, Diabetic, Antihyperglycemic, Lipid peroxidation, Antioxidant, Fasting blood glucose, Creatinine, Urea

Broccoli (Brassica oleracea var. italica) is an important vegetable crop rich in vitamins and sulforaphane. However, the floral heads of broccoli experience rapid postharvest senescence. Here we found that hydrogen sulfide (H2S) treatment alleviated dark-promoted senescence in broccoli florets. H2S delayed the symptoms of senescence and maintained higher levels of chlorophyll and Rubisco and lower protease activity compared with water control. Gene expression analysis showed that H2S down-regulated the expression of chlorophyll degradation-related genes BoSGR, BoNYC, BoCLH1, BoPPH, and BoRCCR. Expression of lipoxygenase gene BoLOX1 and the genes involved in the ethylene synthesis pathway, BoACS2 and BoACS3, were also down-regulated by H2S. The reduced expression level in cysteine protease gene BoCP3 and aspartic protease gene BoLSC807 suggested the role of H2S in alleviating protein degradation during broccoli senescence. H2S up-regulated the expression of sulfur metabolism genes BoSR and BoOASTL, and the antioxidant gene BoCAT. These results show that H2S plays a vital role in alleviating broccoli senescence through a broad regulation on gene expression of reactive oxygen species (ROS) metabolism genes, ethylene synthesis genes, and protease genes.

β-Glucan dietary fiber rich food systems hold a great potential for improving human health. Here, we evaluate the extractability and quality of β-glucan liquid formulations from eight different barley genotypes varying in β-glucan content and molecular structure using Termamyl® SC (T), Attenuzyme® (A) and Attenuzyme® Flex (AF) amylolytic enzymes in combinations. Extracts from barley lines Lys5f, KVL408, KVL1104 and CDC Fibar exceeded 4 g β-glucan/l, providing European Food Safety Authority (EFSA) and U.S. Food and Drug Administration (FDA) recommended amounts (3 g β-glucan/day) from three portions. TAF extracts of Lys5f and KVL408 grains reached extraordinary high concentrations of 8–9 g β-glucan/l. The β-glucan molecular mass decreased with enzyme treatment T

Brown algae are photosynthetic multicellular marine organisms. They belong to the phylum of Stramenopiles, which are not closely related to land plants and green algae. Brown algae share common evolutionary features with other photosynthetic and multicellular organisms, including a carbohydrate-rich cell-wall. Brown algal cell walls are composed predominantly of the polyanionic polysaccharides alginates and fucose-containing sulfated polysaccharides. These polymers are prevalent over neutral and crystalline components, which are believed to be mostly, if not exclusively, cellulose. In an attempt to better understand brown algal cell walls, we performed an extensive glycan array analysis of a wide range of brown algal species. Here we provide the first demonstration that mixed-linkage (1 → 3), (1 → 4)-β-d-glucan (MLG) is common in brown algal cell walls. Ultra-Performance Liquid Chromatography analyses indicate that MLG in brown algae solely consists of trisaccharide units of contiguous (1 → 4)-β-linked glucose residues joined by (1 → 3)-β-linkages. This regular conformation may allow long stretches of the molecule to align and to form well-structured microfibrils. At the tissue level, immunofluorescence studies indicate that MLG epitopes in brown algae are unmasked by a pre-treatment with alginate lyases to remove alginates. These findings are further discussed in terms of the origin and evolution of MLG in the Stramenopile lineage.

Polyphenylene sulfide (PPS) fiber is a kind of high-performance fiber. This paper aimed at investigating the acid resistant performance of PPS fiber. The corrosive action of PPS fiber in nitric acid (HNO3), sulfuric acid (H2SO4), hydrochloric acid (HCl), the mixture of HNO3 and HCl, the mixture of HNO3 and H2SO4, the mixture of HNO3, H2SO4 and HCl were researched. In addition, the influence of various acid concentrations on the performances of the PPS fiber was also studied in the paper. The acid-treated sample was analyzed by the fiber tensile instrument, the Fourier infrared spectrometer, and the scanning electron microscope (SEM) to observe the change of mechanical performance, configuration and appearance.

In this paper, polyphenylene sulfide（PPS） was synthesized through reactions of sodium sulfide and p-dichlorobenzene in N-methylpyrrolidone. Then antioxidant 4426, montmorillonite(MMT) were added into the PPS resin to improve its thermal oxidation stability. The polymer was characterized by FT-IR, Raman, and XRD analysis. Differential Scanning Calorimetry (DSC) was used to mensurate the oxidation induction temperature (dynamic OIT) of PPS, and Thermogravimetric analysis(TGA) was used to evaluate the thermal oxidation stability of PPS. The results showed that the addition of the antioxidant 4426, montmorillonite(MMT) leaded to a good improvement of the thermal oxidation stability of PPS. The PPS's dynamic OIT could up to 480.07°C and 481.61°C after mixed with MMT and anti-oxidant 4426, respectively. the sample of PPS mixed with both MMT and anti-oxidant 4426 has a dynamic OIT of 482.7°C.

Hydroxyapatite (HAP) urchins were synthesized by a facile hydrothermal method using calcium nitrate, ammonium dihydrogen phosphate, diamine tetraacetic acid disodium salt as complexing agent and ethonalamine as alkaline source. The influence of hydrothermal time on crystallinity and morphology of HAP have been investigated. The results indicate that well-crystallized HAP urchins can be synthesized at 180°C for 24h. SEM images show a large area of urchin-like microspheres consisted of a number of ribbons with lengths ranging from 2 to 5μm. Based on XRD and SEM results, the formation mechanism of HAP crystals has been discussed. A typical anti-inflammatory drug, ibuprofen, was used for drug loading, and the release behaviors of ibuprofen in a simulated body fluid (SBF) were studied. The results indicate that HAP urchins showed a favorable sustained release property for ibuprofen.

Calcium sulfate nanorods, nanowires, nanobelts and sheets had been synthesized via a facile solution reaction of CaCl2 and H2SO4 in mixed solvents of ethanol/N, N-dimethylformamide and deionized water at 35°C. The results indicated that well-crystallized CaSO4 nanomaterials with different morphology were obtained by adjusting the volume ratio of ethanol/N, N-dimethylformamide to deionized water and the reaction time. Samples prepared at 35°C in mixed solvents of 50 mL ethanol and 30 mL water for 1 min and 2 h showed nanowire and sheet morphology, respectively. While increasing the volume ratio of ethanol to deionized water to 78/2, only nanorods were obtained. When N, N-dimethylformamide was employed to substitute ethanol, the sample heating at 35°C for 2 h was composed of nanowires in 50 mL N, N-dimethylformamide and 30 mL water. Higher volume ratio of N, N-dimethylformamide to deionized water caused the formation of nanorods.

ZnSn(OH)6hierarchical cubes and Zn2SnO4octahedra have been synthesized through a rapid, template-free, one-pot hydrothermal approach using zinc acetate, tin chloride and sodium hydroxide. ZnSn(OH)6aggregates with cubic morphology and uniform size distribution have been successfully synthesized via aggregation-mediated crystallization. Through adjusting the hydrothermal parameters, Zn2SnO4octahedra were obtained at a higher temperature. The formation of Zn2SnO4 octahedra undergone a transformation from ZnSn(OH)6cubes. The as-synthesized products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and differential scanning calorimetric analysis (DSC) and thermogravimetric analysis (TG).

The main supporting matrix of the edible Nostoc commune colony is polysaccharide, which plays important roles in protecting the cyanobacterium itself from extreme desiccation and high radiation. To explore biomedical potential from the inherent nature of the polysaccharide, we investigated antioxidant and moisture-retention capacities of the polymer. We report here that the polysaccharide is capable of scavenging both superoxide anion and hydroxyl radicals in vitro. Using the model animal Caenorhabditis elegans, we further show that the polysaccharide can increase antioxidant enzyme activity, decrease lipid peroxidation level, and reduce paraquat-induced oxidative damage. We also reveal that the polysaccharide has strong in vitro moisture-absorption and -retention capacities as compared to chitosan and urea, and is able to improve water retention in mouse stratum corneum under dry conditions. Together, these data demonstrate the potent in vitro as well as in vivo antioxidant activities and strong moisture-retention capacities of the polysaccharide from N. commune.

Nitric oxide (NO) is a multifunctional gaseous signal in plant. In the present study, we found that pretreatment with NO could significantly improve wheat seeds germination and alleviate oxidative stress against copper toxicity. With the enhancement of copper stress, the germination percentage of wheat seeds decreased gradually. Pretreatment during wheat seed imbibition with sodium nitroprusside (SNP), an NO donor, could greatly reverse the inhibitory effect of the following copper stress to wheat seeds germination. SNP-pretreated seeds also tended to retain higher amylase activities than that of the control without SNP pretreatment. On the other hand, there was no apparent difference in the activities of esterase in wheat seeds pretreated with or without SNP. Further investigations showed that pretreatment with NO donor dramatically stimulated the activities of superoxide dismutase (SOD, EC 1.15.1.1) and catalase (CAT, EC 1.11.1.6), decreased the activities of lipoxygenases, sustained a lower level of malondialdehyde, and interfered with hydrogen peroxide (H2O2) excessive accumulation compared with the control, thereby enhancing the antioxidative capacity in wheat seeds under copper stress. In addition, the seed copper contents were not significant different between those pretreated with SNP and the controls, inferring that protective roles of NO was not responsible for preventing Cu uptake.

In this work, our study focused on As(2)O(3) action in view point of telomere. Results showed that treatment of human gastric cancer MGC-803 cells with arsenic trioxide could cause up-regulation of telomeric repeat binding factor TRF1 and TRF2 mRNA and protein levels, and induced G2/M phase arrest and cell apoptosis. At the same time, telomere length shortening and telomerase inhibitory were not obvious. Flow cytometry measurements indicated that the increase of TRF1 and TRF2 proteins is related to oxidative stress by arsenic trioxide. Results also indicate that after arsenic trioxide treatment, p53 protein levels increased significantly and also could bind directly at the telomere t-loop junction. These findings demonstrate arsenic trioxide-induced cell cycle arrest and apoptosis might involve a novel pathway related to TRF1, TRF2 protein.

Cadmium selenide (CdSe) thin films have been electrodeposited on the titanium or ITO substrate in an electrolyte containing CdSO4 and H2SeO3 at pH = 2.50 and temperature 298 K. Influence of different deposition potentials on the surface morphology CdSO4 and H2SeO3 at pH = 2.50 and temperature 298 K. Influence of different deposition potentials on the surface morphology and crystal structure of CdSe films has been discussed. Compared with other deposition potentials (-0.65, -0.71 and -0.72 V versus SCE), the nearly stoichiometric CdSe nanocrystalline films with smaller grain sizes of 80 nm were obtained from 0.25 M CdSO4 + 0.25 mM H2SeO3 + 0.25 M Na2SO4 solution at deposition potential of -0.70 V versus SCE. X-ray diffraction, atomic force microscope and scanning electron microscope were used to measure structure and morphology of CdSe films. The results indicated that the electrodeposited films were the smooth, compact and uniform at deposition potentials of -0.70 V versus SCE. (C) 2004 Elsevier B.V. All rights reserved.

The role of homocysteine for store-operated calcium influx was investigated in human umbilical cord endothelial cell line. Homocysteine significantly decreased thapsigargin-evoked Ca2+ entry, membrane hyperpolarization and actin polymerization. GSH and DTT prevented homocysteine-induced inhibition of thapsigargin-evoked Ca2+ entry, membrane hyperpolarization and actin polymerization; while GSSG had the opposite effect. Homocysteine blocked large conductance Ca2+-activated K+ (BKCa) channels in a concentration-dependent manner and related to the redox status of the endothelial cells. BKCa channels opener NS1619 reversed thapsigargin-evoked Ca2+ entry, membrane hyperpolarization and actin polymerization; BKCa channels inhibitor iberiotoxin had the opposite effect. The findings suggest that homocysteine is involved in store-regulated Ca2+ entry through membrane potential-dependent and actin cytoskeleton-dependent mechanisms, redox status of homocysteine and BKCa channels may play a regulatory role in it. (Mol Cell Biochem 269: 37–47, 2005)

The tumor suppressor p53 regulates the expression of various genes that promote apoptosis. PIG11 (P53-induced gene 11), also referred to as TP53I11 (tumor protein p53 inducible protein 11), is a direct p53 target gene. Recent data demonstrated that PIG11 was up-regulated markedly in arsenic trioxide induced apoptosis by DDRT-PCR, suggesting a new class of p53 target genes that sensitize cells to the effects of chemotherapeutic agents. In this study, through the construction of a recombinant GFP-PIG11 expression vector and transfection of HEK293 cells with GFP or GFP-PIG11, the role of PIG11 in apoptosis was analyzed. Results demonstrated that the percentage (11.38%) of apoptotic cells with GFP-PIG11 transfection was higher than that (7.28%) of with only GFP transfection (P0.05). At 24 h after 1 microM of arsenic trioxide treatment, apoptotic cells exhibited a significant increase in the expression of GFP-PIG11 (36.67%+/-2.78), in contrast, 10.50%+/-2.03 only GFP and 5.25%+/-0.96 vehicle control (P0.01). In addition, we showed that intracellular content of reactive oxygen species (ROS) was 9.66+/-0.52 in GFP-PIG11 transfection, higher than 5.21+/-0.08 in GFP only and 5.99+/-0.45 in vehicle control (P0.01). The above results suggest that overexpression of PIG11 could induce cell apoptosis in the low levels and enhanced the apoptotic effects of arsenic trioxide. The process could be involved in intracellular generation of ROS.

In this work, we investigated the synergic effects between low-dose arsenic trioxide and diethyloxadicarbocyanine (DODC), a telomerase inhibitor, on cell apoptosis. Results revealed that low-dose arsenic could block cell cycle arrest at the G2/M phase and induce apoptosis, whereas DODC could block cell cycle arrest at the G0/G1 phase but not induce apoptosis. However, cells pretreated with DODC showed greater sensitivity to arsenic than untreated cells. The percentage of apoptosis produced by combination treatment with the two agents increased and that was similar to the effect of high-dose arsenic treatment alone. Further studies showed that DODC alone could induce hairpin G-quadruplex formation and inhibit telomerase activity in a dose-dependent manner. Compared with HT1080 cells, 293 cells were more sensitive to cell growth inhibition and apoptosis and were less sensitivity to telomerase activity. These results indicate that DODC can synergistically enhance the apoptosis induced by arsenic, suggesting the increased cell senescence in response to arsenic is induced by an altered telomere state rather than by a loss of telomerase. Thus clinical application of combination treatment with arsenic and telomerase inhibitor may have potential in cancer therapy.

Opposite biological effects of arsenic trioxide (As2O3) and arsacetin on the growth of human gastric cancer MGC-803 cells have been observed. Results show that As2O3 inhibited the growth of MGC-803 cells by triggering apoptosis, whereas arsacetin promoted the cell proliferation and seemed to stimulate the secretion of some growth factors at the same micromolar concentrations. Further studies showed that As2O3 could regulate protein tyrosine kinase activity, protein tyrosine phosphorylation, and Bcl-2 protein and upregulate p53 protein. The ability of arsacetin to promote cell proliferation is linked with causing the opposite effects on these factors. These results indicate that the opposite biological effects of As2O3 and arsacetin involve different regulations of molecular mechanisms in MGC-803 cells and that arsacetin may be a potential tumor promoter.

Telomeres are an essential nucleoprotein structure at the ends of all eukaryotic chromosomes. Studies on the structure and function of telomeres have received particular attention owing to their possible significance to ageing and cancer. In this work, human telomere from HeLa cells were isolated and purification by bio-gel P-2 column. Large duplex loops with a tail were first observed directly in the purified telomeric DNA species by atomic force microscopy (AFM). The lengths of the loop and tail are ∼2.5 ± 0.5 and 2.0 ± 1.5 kb, respectively. The AFM images also showed that the circular portion of loops is assumed to be a double-stranded structure according to its apparent height, but to be a triplex or tetraplex structure for the loop-tail junction. These results indicate that telomeres in human cells may end in large loops, which is an advantage in further studies on the structure and function of telomeres in cells and provides a new procedure for the study of telomere structure.

Arsenic trioxide (As2O3), used to treat human diseases for centuries in traditional Chinese medicine, has been identified as a very effective antileukaemic agent, but its effect on solid tumours which could be more suitable for clinical treatment with arsenic compounds is still unknown. In this study, we investigated the in vitro effect of As2O3 at concentrations of 0.01-1 microM against six human malignant cell lines, MGC-803, HIC, MCF-7, HeLa, BEL-7402 and A549 cells. As2O3 inhibited growth and induced apoptosis in these malignant cells at varying degrees, in a time dose-dependent manner. The most marked effects were seen in the gastric cancer cell line, MGC-803. In contrast, minimal growth inhibition and induction of apoptosis occurred in human embryonic pulmonary cells following treatment with As2O3 found at the same concentrations. Changes in intracellular Ca2+, following As2O3 treatment were measured by Ca2+ sensitive fluorescent probe Indo-1/AM in flow cytometric assays. The increase in intracellular Ca2+ correlated with the sensitivity of these cells to As2O3, possibly indicating that a critical intracellular Ca2+ signal transduction pathway could be involved in As2O3-mediated cell-death and its selectivity. The marked sensitivity of MGC-803 cells in vitro suggests that As2O3 may be a potential antigastric cancer agent.

Water-soluble (1 → 3)-β- d -glucans with 1,6-linked branches (SBG) isolated from the cell walls of Saccharomyces cerevisiae were studied by size exclusion chromatography (SEC) with multi-angle laser light scattering (MALLS) detector using dimethylacetamide (DMAc) containing 0.5% (0.12 M) LiCl, or dimethyl sulphoxide (DMSO) in the absence and presence of 0.25 M LiCl, respectively, as eluents. The aggregating glucan could be dispersed as single chains in both solvents, with chain length distributions in reasonable agreement with results obtained previously with carboxymethylated glucans in aqueous solvent. However, DMAc is preferred over DMSO because of higher sensitivity in MALLS, and also because the latter produces SEC anomalies. SBG dissolves slowly in DMAc/LICl at room temperature, but heating accelerates the process. The rate of depolymerisation of SBG in DMAc/LiCl at high temperatures (70–105 °C) was determined as a basis for defining dissolution procedures at elevated temperatures with a minimum of degradation. The result of the investigation is a simple and reliable protocol for preparing unaggregated, fully dissolved and undegraded SBG in DMAc/LiCl, which is well suited as a standard analysis of the molecular weight distribution of SBG-like molecules without chemical derivatization.

Telomeres are essential nucleoprotein structure at the ends of all eukaryotic chromosomes. Our previous work demonstrated that mammalian telomeres were shown to end in a large t-loop structure in vitro and the formation of t-loops was dependent on the presence of TRF2. In this work, the telomere DNA and its complex of TRF2 in HeLa cells has been direct observed in the nanometer resolution regime by atomic force microscopy (AFM) and scanning near-field optical microscopy (SNOM). AFM images showed that the looped structures exited in cell extract containing TRF2, but it disappeared in the protein-deleted samples. When cells were pretreated by UV light plus psoralen, the looped structure could be observed in the protein-deleted samples. SNOM images further demonstrated TRF2 and p53 proteins in cell was bound at the loop junction. Above results suggest that the telomere t-loop structure by TRF2 play a important role in cell-senescence, and might signals p53 protein directly through association with the t-loop junction in cells.

Arsenic trioxide (As 2 O 3 ) has been used as an effective chemotherapy agent for some human cancer, such as acute promyelocytic leukemia. We have demonstrated that low level of As 2 O 3 relatively selectively inhibited growth of the solid tumor MGC-803 cells by triggering apoptosis. In this study, we found PIG11, a p53-induced gene, was upregulated markedly by As 2 O 3 using the technique of differential display reverse transcriptase PCR (DDRT-PCR). Addition of anti-PIG11 phosphorothioated oligonucleotide (5'-GGC CGC CAT CTT CTC CTC-3') before As 2 O 3 treatment, abolished the transient increase in PIG11 gene expression. Furthermore, it significantly inhibited the As 2 O 3 -induced apoptosis of MGC-803 cells, but had no effect in addition of missense (5'-GAG GAG AAG ATG GCG GCC-3') phosphorothioated oligonucleotides. These results suggest that PIG11, as a downstream target of p53, is involved in apoptosis of MGC-803 cells.

Homocystinemia has been identified as an independent risk factor for atherosclerosis. Monocyte chemoattractant protein-l (MCP-l) is a potent chemokine that stimulates the migration of monocytes into the intima of the arterial wall. The authors investigated the role of intracellular redox status in the expression of MCP-l stimulated by homocysteine in endothelial cells. Homocysteine stimulated MCP-1 mRNA expression and protein production in a time-dependent and dose-dependent manner in endothelial cells, decreased intracellular glutathione (GSH) and protein thiol levels, as well as G6PDH activity and NADPH levels. Thiol reduced reagents, GSH, and dithiothreitol levels, and reversed the MCP-l mRNA expression and protein production in endothelial cells; in addition, thiol oxidized reagent, diamide, and BSO levels, and markedly potentiated homocysteine-mediated up-regulation of MCP-l mRNA expression and protein production in endothelial cells. These results demonstrate that homocysteine can trigger overexpression of the MCP-1 gene by altering the intracellular redox status, suggesting that the homocysteine-induced changes in the intracellular redox status play an important role in modulating the expression of MCP-l in endothelial cells.

We have investigated the action of oxidative stress in arsenite-induced apoptosis of human gastric cancer MGC-803 cells. Cells exhibited obvious characteristic of apoptosis following the treatment with 1.0 microM arsenite for 24 h. During the process, low concentration of arsenite significantly increased superoxide formation and lipid peroxidation, which was dose-dependent and was related to cell apoptosis induced by arsenite. The oxidant-dependent increase in intracellular [Ca(2+)] level and p53 gene expression were also observed at the same time. A phospholipase C inhibitor, 1-[6-([(17 beta)-3-methoxyestra-1,3,5,(10)-trien-17-yl]-amino)hexyl]-2,5-dione (U73122), could block the rapid transient increase in intracellular Ca(2+) levels, as well as the subsequent fragmentation of nuclear DNA. Addition of alpha-tocopherol before arsenite treatment abolished the transient increase in superoxide formation, lipid peroxidation, intracellular [Ca(2+)] levels and p53 gene expression, and furthermore could significantly inhibited the arsenite-induced apoptosis of MGC-803 cells. These results indicate that arsenite-induced oxidative stress, which stimulate cellular signaling systems, are involved in apoptosis of MGC-803 cells.

DNA from HeLa cells was cleaved with Rasl and Hinf, and then purified by Bio-Gel P-2 column. Results showed that upon near-UV-irradiation, psoralen could be targeted to the repetitive sequences of telomeres. Large duplex loops with a tail were observed directly by AFM. The loop-tail junction position was assumed to be a tri- or tetra- strand DNA structure according to its apparent height, corresponding structure model was proposed. The psoralen cross-linking products increased with increase of irradiation time. The expression of p53 oncogene was significantly increased.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Copper in the presence of excess 1,10-phenanthroline, a reducing agent, and H2O2 causes DNA base damage as well as strand breakage. We have reported in previous work that a strong chemiluminescence was followed by DNA base damage in this system, which is characteristic of guanine. In the present work, the mechanism of the chemiluminescence was studied. Results show that the luminescence was inhibited by all three classes of reactive oxygen species (*OH, O2-, (1)O2) scavengers to different degrees. Singlet oxygen scavengers showed the most powerful inhibition while the other two classes of scavengers were relatively weaker. The emission intensity in D2O was 3-fold that in H2O. Comparing the effect of scavengers on the luminescence of DNA with that of dGMP, the ratio of inhibition was similar. On the other hand, DNA breakage analysis showed that inhibition by the singlet oxygen scavenger NaN3 of strand breakage was strong and comparable to that of the scavengers of the two oxygen radicals. The results suggest that singlet oxygen may be a major factor for the chemiluminescence of guanine, while DNA strand breakage may be caused by many active species.

Fifty-eight acute promyelocytic leukemia (APL) patients (11 newly diagnosed and 47 relapsed) were studied for arsenic trioxide (As2O3) treatment. Clinical complete remission (CR) was obtained in 8 of 11 (72.7%) newly diagnosed cases. However, As2O3 treatment resulted in hepatic toxicity in 7 cases including 2 deaths, in contrast to the mild liver dysfunction in one third of the relapsed patients. Forty of forty-seven (85.1%) relapsed patients achieved CR. Two of three nonresponders showed clonal evolution at relapse, with disappearance of t(15;17) and PML-RAR fusion gene in 1 and shift to a dominant AML-1-ETO population in another, suggesting a correlation between PML-RAR expression and therapeutic response. In a follow-up of 33 relapsed cases over 7 to 48 months, the estimated disease-free survival (DFS) rates for 1 and 2 years were 63.6% and 41.6%, respectively, and the actual median DFS was 17 months. Patients with white blood cell (WBC) count below 10 × 109/L at relapse had better survival than those with WBC count over 10 × 109/L (P = .038). The duration of As2O3-induced CR was related to postremission therapy, because there was only 2 of 11 relapses in patients treated with As2O3 combined with chemotherapy, compared with 12 of 18 relapses with As2O3 alone (P = .01). Reverse transcription polymerase chain reaction (RT-PCR) analysis in both newly diagnosed and relapsed groups showed long-term use of As2O3 could lead to a molecular remission in some patients. We thus recommend that ATRA be used as first choice for remission induction in newly diagnosed APL cases, whereas As2O3 can be either used as a rescue for relapsed cases or included into multidrug consolidation/maintenance clinical trials.