Search

The development of enantioselective desymmetrization of para-quinamines with isocyanates catalyzed by chiral phosphoric acid is reported. The strategy provides concise access to functionalized imidazolidin-2-one derivatives in high yields and enantioselectivities under mild reaction conditions. Remarkably, this reaction could be performed on a gram scale using 5 mol % catalyst loading and the chiral imidazolidin-2-one derivatives could be easily transformed into valuable scaffolds without disturbing the enantiopurity, demonstrating the synthetic utility of this protocol.

Preeclampsia is a pregnancy complication which threatens the survival of mothers and fetuses. It originates from abnormal placentation, especially insufficient fusion of the cytotrophoblast cells to form the syncytiotrophoblast. In this study, we found that THBS1, a matricellular protein that mediates cell-to-cell and cell-to-matrix interactions, is downregulated during the fusion of primary cytotrophoblast and BeWo cells, but upregulated in the placenta of pregnancies complicated by preeclampsia. Also, THBS1 was observed to interact with CD36, a membrane signal receptor and activator of the cAMP signaling pathway, to regulate the fusion of cytotrophoblast cells. Overexpression of THBS1 inhibited the cAMP signaling pathway and reduced the BeWo cells fusion ratio, while the effects of THBS1 were abolished by a CD36-blocking antibody. Our results suggest that THBS1 signals through a CD36-mediated cAMP pathway to regulate syncytialization of the cytotrophoblast cells, and that its upregulation impairs placental formation to cause preeclampsia. Thus, THBS1 can serve as a therapeutic target regarding the mitigation of abnormal syncytialization and preeclampsia.

Two states of aluminum alloy material 7B04 T651 and 7B04 T74 using C-ring specimen were selected to carry out stress corrosion simulation test with different stress levels, corrosion concentrations and time, and the fracture morphology of the crack was observed and analyzed by optical microscope and scanning electron microscope (SEM). The results showed that 7B04-T74 alloy was insensitive to stress corrosion and was not prone to stress corrosion cracking under constant tensile stress lower than 432MPa; The stress corrosion cracking time of 7B04 T651 alloy under three different concentrations has no significant difference, and the stress corrosion cracking occurs within 7 days under the stress of 180MPa-432MPa. The time of stress corrosion cracking increased with the decrease of stress. Stress corrosion cracking (SCC) was very sensitive to Cl element, and it was also easy to produce SCC when the concentration of corrosive medium was low, the threshold value of corrosion cracking was about 108 MPa. SEM and EDS analysis showed that the fracture surface was intergranular, mud-like corrosion products, and secondary cracks. At the same time, the matrix grain boundaries were weakened by Cl element.

During postulated severe accident, large amount of hydrogen-vapor mixture will be released into the containment and inflammable gas mixture may form. Once the gas will be ignited, the generated pressure loads can jeopardize the integrity of the internal structures. As the local accumulation of high content hydrogen related much to the stratification and erosion mechanism, it is therefore of interest whether a stratification of gas layers will form within small containment. In this study, a stratification/erosion experiment is performed and the criteria under which the steady stratification will be destroyed by steam jet discussed. Then the simulation method is validated by the experimental data. At last, several severe accident scenarios for Chinese SMR performed and one of them is adopted for containment hydrogen CFD analysis. It is shown that high content of hydrogen will form in the upper part of the containment, and clear gas stratification will form, such stratification will be enhanced due to the condensation effect of steel containment wall.

Syngas production from dry reforming of biogas (DRB) is studied experimentally in this work. Ni/Al2O3, Pt/Al2O3, and Pt-Ni/Al2O3 are used as catalysts to examine the effect of CO2 content in biogas and H2O addition on DRB performance for reaction temperatures in the 600–800 °C range. It is found that the bimetallic Pt–Ni catalyst exhibits the best activity and thermal stability among the three types of catalysts studied due to better carbon deposition resistance. Because CO2 functions as the oxidant in combustion, CH4 conversion is enhanced when the biogas contains more CO2. One hundred percent CO2 conversion can be reached for biogas containing a less amount of CO2 at high temperatures. With H2O addition in DRB, the steam reforming of methane (SRM) reaction is the dominant reaction, resulting in higher H2 and CO yields with biogas containing lesser amounts of CO2. However, lower CH4 conversion and negative CO2 conversion do result. With higher CO2 content in the biogas, higher CH4 and CO2 conversions can be obtained. Lower yields of H2 and CO are obtained due to less SRM dominance. With H2O addition in biogas, the H2/CO ratio with a value greater than 1 can be obtained from DRB. It is also found that the H2/CO ratio with a value of 2.1 can be obtained for reactant composition with a molar ratio of CH4/CO2/H2O = 1:0.25:1 and reaction temperature of 800 °C.

Astrocytic calcium signaling plays pivotal roles in the maintenance of neural functions and neurovascular coupling in the brain. Vascular endothelial growth factor (VEGF), an original biological substance of vessels, regulates the movement of calcium and potassium ions across neuronal membrane. In this study, we investigated whether and how VEGF regulates glutamate‐induced calcium influx in astrocytes. We used cultured astrocytes combined with living cell imaging to detect the calcium influx induced by glutamate. We found that VEGF quickly inhibited the glutamate/hypoxia‐induced calcium influx, which was blocked by an AMPA receptor antagonist CNQX, but not D‐AP5 or UBP310, NMDA and kainate receptor antagonist, respectively. VEGF increased phosphorylation of PKCα and AMPA receptor subunit GluA2 in astrocytes, and these effects were diminished by SU1498 or calphostin C, a PKC inhibitor. With the pHluorin assay, we observed that VEGF significantly increased membrane insertion and expression of GluA2, but not GluA1, in astrocytes. Moreover, siRNA‐produced knockdown of GluA2 expression in astrocytes reversed the inhibitory effect of VEGF on glutamate‐induced calcium influx. Together, our results suggest that VEGF reduces glutamate‐induced calcium influx in astrocytes via enhancing PKCα‐mediated GluA2 phosphorylation, which in turn promotes the membrane insertion and expression of GluA2 and causes AMPA receptors to switch from calcium‐permeable to calcium‐impermeable receptors, thereby inhibiting astrocytic calcium influx. The present study reveals that excitatory neurotransmitter glutamate‐mediated astrocytic calcium influx can be regulated by vascular biological factor via activation of AMPA receptor GluA2 subunit and uncovers a novel coupling mechanism between astrocytes and endothelial cells within the neurovascular unit.

Heavy metal contamination in water bodies is currently in an area of greater concern due to the adverse effects on human health. Despite the good adsorption performance of biochar, various modifications have been performed on the pristine biochar to further enhance its adsorption capability, at the same time overcome the difficulty of particles separation and mitigate the secondary pollution issues. In this review, the feasibility of chitosan-modified magnetic biochar for heavy metal removal from aqueous solution is evaluated by critically analysing existing research. The effective strategies that applied to introduce chitosan and magnetic substances into the biochar matrix are systematically reviewed. The physicochemical changes of the modified-biochar composite are expounded in terms of surface morphology, pore properties, specific surface area, surface functional groups and electromagnetism. The detailed information regarding the adsorption performances of various modified biochar towards different heavy metals and their respective underlying mechanisms are studied in-depth. The current review also analyses the kinetic and isotherm models that dominated the adsorption process and summarizes the common models that fitted well to most of the experimental adsorption data. Moreover, the operating parameters that affect the adsorption process which include solution pH, temperature, initial metal concentration, adsorbent dosage, contact time and the effect of interfering ions are explored. This review also outlines the stability of modified biochar and their regeneration rate after cycles of heavy metal removal process. Lastly, constructive suggestions on the future trends and directions are provided for better research and development of chitosan-modified magnetic biochar.

The presence of ice and snow on a road surface in winter will reduce the traffic capacity of the road network, which can easily lead to traffic accidents. In this study, nonchlorine organic snow-melting salt was added to emulsified asphalt to prepare an anticoagulant ice fog seal. Considering the destructive effect of snow-melting salt on the stability of emulsified asphalt, polyvinyl alcohol was used as an encapsulation material to form a stable two-phase system by mixing snow-melting salt with emulsified asphalt. The zeta potential method was used to test the storage stability of the encapsulated salt solution. The results showed that the material and content of the encapsulation had a significant effect on the stability of the emulsified asphalt and the reduction in the freezing point of the encapsulated salt solution. PVA (1.5%) mixed with 24% sodium acetate was used to prepare an encapsulated salt emulsion, which was mixed with anionic emulsified asphalt and sprayed on the road surface. This significantly reduced the freezing point of road surface water. The recommended spraying dosage of the anticoagulant ice fog seal layer was 0.4 kg/m2, which could lower the freezing point by at least −8°C while simultaneously meeting the antislip performance condition. This was shown to be a preventive maintenance technology with both anticoagulant ice and maintenance effects.

This paper aims at the problem of spot-shaped defects caused by the cleaning process of the profile of 2196 Al-Li alloy, Fluorescence detection combined with metallographic microscope was used for detection, The results showed that the pitting and intergranular corrosion were observed in the pitting defects. Therefore, it is proposed to simulate each cleaning process, analyze the defect morphology generated under different states, and explain the cause of defect formation. The final test results showed that water washing, pickling and water immersion exposure could lead to pitting and intercrystalline corrosion of 2196 Al-Li alloy. Thus, it was analyzed that the defect was caused by the formation of AlCl3 and Al (OH) 3 products after the sample reacted with liquid during the cleaning process. When these two products are more concentrated, The grain boundary is subjected to tensile stress due to volume expansion, It leads to point-like defects in al - Li alloy along grain boundary.

High-nickel ternary LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode materials modified by Na-doping and MgF2 coating are synthesized by high-temperature solid-phase method. The morphology and structure of the materials are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrochemical performances test shows that the initial discharge specific capacity of the pristine NCM811 sample is 173 mAh/g at 0.5C, and the discharge specific capacity after 100 cycles is 131 mAh/g. However, when the doping amount of sodium ion is 0.05, 0.1, 0.15 respectively (NCM811-0.05Na, NCM811-0.1Na, NCM811-0.15Na), the corresponding initial discharge specific capacity of the sample is 187, 191, 179 mAh/g, and the corresponding discharge specific capacity after 100 cycles is 140, 158, 119 mAh/g. Discharged at 0.1, 0.5, 1, 2, 5 and 10C rate, the discharge specific capacity for the pristine NCM811 samples is 193, 170, 156, 138, 106 and 79 mAh/g respectively, while the corresponding value for NCM811-0.1Na samples is 203, 191, 180, 165, 137 and 105 mAh/g respectively. And for the sample modified by Na doping and MgF2 coating (NCM811-Na@MgF2), the corresponding discharge specific capacity is 210, 196, 183, 172, 146 and 126 mAh/g respectively. It can be seen that the synergistic modification by Na doping and MgF2 coating is beneficial to the improvement of electrochemical performances of high nickel ternary NCM811 cathode material.

Reactive astrocytes induced by ischemia can transdifferentiate into mature neurons. This neurogenic potential of astrocytes may have therapeutic value for brain injury. Epigenetic modifications are widely known to involve in developmental and adult neurogenesis. PAX6, a neurogenic fate determinant, contributes to the astrocyte-to-neuron conversion. However, it is unclear whether microRNAs (miRs) modulate PAX6-mediated astrocyte-to-neuron conversion. In the present study we used bioinformatic approaches to predict miRs potentially targeting Pax6, and transient middle cerebral artery occlusion (MCAO) to model cerebral ischemic injury in adult rats. These rats were given striatal injection of glial fibrillary acidic protein targeted enhanced green fluorescence protein lentiviral vectors (Lv-GFAP-EGFP) to permit cell fate mapping for tracing astrocytes-derived neurons. We verified that miR-365 directly targets to the 3'-UTR of Pax6 by luciferase assay. We found that miR-365 expression was significantly increased in the ischemic brain. Intraventricular injection of miR-365 antagomir effectively increased astrocytic PAX6 expression and the number of new mature neurons derived from astrocytes in the ischemic striatum, and reduced neurological deficits as well as cerebral infarct volume. Conversely, miR-365 agomir reduced PAX6 expression and neurogenesis, and worsened brain injury. Moreover, exogenous overexpression of PAX6 enhanced the astrocyte-to-neuron conversion and abolished the effects of miR-365. Our results demonstrate that increase of miR-365 in the ischemic brain inhibits astrocyte-to-neuron conversion by targeting Pax6, whereas knockdown of miR-365 enhances PAX6-mediated neurogenesis from astrocytes and attenuates neuronal injury in the brain after ischemic stroke. Our findings provide a foundation for developing novel therapeutic strategies for brain injury.

A highly crystalline nanosized spinel LiMn2O4/3DG composite cathode material for high rate lithium ion batteries was successfully prepared by mixing spinel LiMn2O4 particles with reduced graphene oxide (3DG). Spinel LiMn2O4 and reduced three-dimensional graphene oxide were synthesized using a hydrothermal method and freeze-drying technology, respectively. The structure, morphology and electrochemical performance of the synthesized materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge–discharge techniques. The results showed that the LiMn2O4/3DG composites exhibited excellent rate capability and stable cycling performance. The discharge capacity was 131 mA h g−1 and the capacity remains at 89.3% after 100 cycles at a 0.5 C rate, while the discharge capacity was 90 mA h g−1 at 10 C. Compared with spinel LiMn2O4 materials, the LiMn2O4/3DG composites showed obvious improvement in electrochemical performance.

Scandium-catalyzed asymmetric Claisen rearrangement reactions of 2-allyloxyindoles and 2-propargyloxyindoles provide a novel approach to diverse 3-allyloxindoles and 3-allenyloxindoles in excellent yields (up to 99%) and enantioselectivity (up to 99% ee) under mild reaction conditions. The scandium catalyst was derived from Sc(OTf)3 and Pybox ligand.

In this study, we focused on studying the changes in urine metabolites in hyperlipidemic rats using ultra-performance liquid chromatography coupled with quadrupole time-of-fight mass spectrometry (UPLC-Q-TOF/MS) and metabolomics, as well as the effect of Citri Reticulatae Chachiensis Pericarpium (CRCP) on hyperlipidemia. These urine samples were examined by UPLC-Q-TOF/MS to obtain MS data. The MS data were analyzed by principal component analysis and partial least squares-discriminant analysis to identify the differential metabolites. CRCP reduced the body weight and levels of triglycerides, total cholesterol and low-density lipoprotein cholesterol and abnormally decreased high-density lipoprotein cholesterol in hyperlipidemic rats, which were significantly raised by a high-fat diet. Twenty-seven potential biomarkers were identified within the complex sample matrix of urine. Fourteen biomarkers increased in the hyperlipidemia rats compared with normal rats. Meanwhile, 13 biomarkers decreased. CRCP reversed abnormal changes in biomarkers, including 5-l-glutamyl-taurine, 5-aminopentanoic acid, cis-4-octenedioic acid and 2-octenedioic acid. These biomarkers show that hyperlipidemia is related to the metabolic pathways of taurine and hypotaurine metabolism, fatty acid biosynthesis, and arginine and proline metabolism. CRCP mainly prevents hyperlipidemia by intervening in these metabolic pathways.

In this study, a novel multifunctional composite membrane with photocatalytic, antifouling and self-cleaning properties were prepared through the surface immobilization of nitrogen doped carbon quantum dots modified TiO2 (NCQDs-TiO2) photocatalysts using polyacrylic acid (PAA) as a bridging agent. The surface polymerization of PAA has introduced functional groups for the self-assembly of NCQDs-TiO2 functional layer (denoted as NTO) to improve the hydrophilicity of conventional PES membrane. The modified membranes with varying photocatalyst concentration (0.1, 0.3 and 0.5 wt% NTO) were characterized for their surface chemistry and morphology using SEM-EDX, FTIR, XPS and contact angle analysis. Furthermore, the effect of NCQDs-TiO2 nanocomposite on the membrane performance was assessed in terms of rejection ability, fouling mitigation, self-cleaning and photocatalytic capability using methylene blue as a model pollutant. The characterization results evidenced that the NTO nancomposites were firmly attached on the PES-based supporting layer through the chemical bonding between surface-grafted carboxylic group and Ti atom. The surface hydrophilicity of composite membrane was enormously enhanced following a direct proportionality to NTO loading. The novel NTO/PAA/PES membrane also demonstrated high resistance to MB fouling and was able to revive 93.7% of original water fluxes upon 15 min of visible-light irradiation. Moreover, the modified membranes could efficiently retain 90.9% of MB dye pollutant. The outstanding antifouling and self-cleaning performance were reasonably attributed to the intrinsic hydrophilicity and robust photocatalytic activity of NTO layer. This was further confirmed by the photodegradation of MB wherein the NTO-0.5/PAA/PES membrane degraded 94.9% of MB under 1 hr of visible-light irradiation. With its twofold advantages of membrane filtration and photocatalysis, the visible-light responsive photocatalytic membrane demonstrates huge potential in waste water treatment which could minimize membrane fouling and increase reusability of photocatalyst.

Due to the large band gap and the rapid recombination of electron-hole pairs of TiO2, carbon quantum dots (CQDs) modified TiO2 photocatalyst had been given intensive attention in visible light photodegradation. In this study, the oil palm frond-derived NCQDs/TiO2 was adopted for the first time in the photodegradation of Methylene Blue (MB) under visible light irradiation. TiO2 photocatalyst and NCQDs/TiO2 nanocomposites with different NCQDs contents were successfully synthesised through a facile in-situ hydrothermal method. The surface morphology and crystalline structure of NCQDs-decorated semiconductor photocatalyst were characterized by high-resolution transmission electron microscope (HRTEM), field emission scanning electron microscope (FESEM) and X-ray diffraction (XRD), respectively. Fourier transform infrared spectroscopy (FTIR) and energy dispersive X-ray (EDX) were utilized to prove the successful attachment and the uniform dispersion of NCQDs on TiO2 surface, respectively. The best-performed photocatalyst with the optimum amount of NCQDs (NCQDs/TiO2-1) displayed a degradation efficiency of 40.9% within 60 minutes, which is 2.6 times faster than that of pure TiO2 (15.6%). The improved photocatalytic performance could be attributed to the better charge separation since NCQDs act as an electron reservoir which impeded the recombination of electron-hole pairs. The present work proposed a simple synthetic route for the preparation of NCQDs/TiO2 nanocomposites and the use of biomass as a natural precursor which contributed to green and sustainable fabrication of photocatalyst in environmental application.

Using ultra high performance liquid chromatography quadrupole/time-of-flight mass spectrometry (UPLC-QTOFMS) based metabolomics, we focused on developing a method for the comprehensive distinction between Citri Reticulatae Blanco Pericarpium(CRBP) and Citri Reticulatae Chachi Pericarpium (CRCP), as well as the CRCP within different storage years in this study. Through this, we hope to enhance Citri Reticulatae Pericarpium (CRP) Quality Control system. Using UNIFI software and an online database identified chemical components in the 3-30 years CRCP(40 batches) and CRBP (10 batches)samples, and multivariate statistical analysis methods and heat-map were applied to distinguish between CRCP and CRBP and CRCP in different storage years. The results showed that a total of 92 compounds were identified from CRCP and CRBP samples, most of which were flavonoids. Principal component analysis (PCA) and orthogonal partial least squares discrimination analysis (OPLS-DA) indicated that it can effectively distinguish between CRBP and CRCP and various storage years CRCP, and 19 metabolites were identified as potential markers for distinguishing between CRBP and CRCP, and 15 potential markers showed a higher level of CRCP than CRBP. At the same time, 31 metabolites were identified to distinguish CRCP in different storage years, metabolite levels increased in 3-10 years and decreased after 15-30 years. Therefore, this approach can effectively distinguish between CRCP and CRBP and CRCP with different storage years, and may also provide a feasible strategy for the certification of Chinese herbal medicines from different species and storage years.

Axon-transport plays an important role in neuronal activity and survival. Reduced endogenous VEGF can cause neuronal damage and axon degeneration. It is unknown at this time if VEGF can be transported within the axon or whether it can be released by axonal depolarization. We transfected VEGF-eGFP plasmids in cultured hippocampal neurons and tracked their movement in the axons by live-cell confocal imaging. Then, we co-transfected phVEGF-eGFP and kinesin-1B-DsRed vectors into neurons and combined with immunoprecipitation and two-color imaging to study the mechanism of VEGF axon-trafficking. We found that VEGF vesicles morphologically co-localized and biochemically bounded with kinesin-1B, as well as co-trafficked with it in the axons. Moreover, the capacity for axonal trafficking of VEGF was reduced by administration of nocodazole, an inhibitor of microtubules, or kinesin-1B shRNA. In addition, we found that VEGF could release from the cultured neurons under acute depolarizing stimulation with potassium chloride. Therefore, present findings suggest that neuronal VEGF is stored in the vesicles, actively released, and transported in the axons, which depends on the presence of kinesin-1B and functional microtubules. These results further help us to understand the importance of neuronal VEGF in the maintenance of neuronal activity and survival throughout life.

A class of novel, easily accessible and air-stable 1-[bis(trifluoromethyl)phosphine]-1’-oxazolinylferrocene ligands has been synthesized from ferrocene. It became apparent that these ligands can be used in the regio- and enantioselective Pd-catalyzed allylic alkylation of monosubstituted allyl substrates in a highly efficient manner. Excellent regio- and enantioselectivity could be obtained for a wide range of substrates.

Gentamicin C1a is an important precursor to the synthesis of etimicin, a potent antibiotic. Wild type Micromonospora purpurea Gb1008 produces gentamicin C1a, besides four other gentamicin C components: C1, C2, C2a, and C2b. While the previously reported engineered strain M. purpurea GK1101 can produce relatively high titers of C1a by blocking the genK pathway, a small amount of undesirable C2b is still being synthesized in cells. Gene genL (orf6255) is reported to be responsible for converting C1a to C2b and C2 to C1 in Micromonospora echinospora ATCC15835. In this work, we identify the genL that is also responsible for the same methylation in Micromonospora purpurea. Based on M. purpurea GK1101, we construct a new strain with genL inactivated and show that no C2b is produced in this strain. Therefore, we successfully engineer a strain of M. purpurea that solely produces gentamicin C1a. This strain can potentially be used in the industrial production of C1a for the synthesis of etimicin.

LiNi1/3Co1/3Mn1/3O2 (LNCM) cathode material with high specific capacity has been received extensive attention in power batteries. However, the poor cycle performance and serious safety issues limit its application prospect. In this paper, the technology of surfactant-assisted hydrothermal synthesis combined with vanadium pentoxide (V2O5) coating is applied in LNCM cathode material. Firstly, the Ni1/3Co1/3Mn1/3CO3 precursor with good dispersibility and uniform morphology is synthesized by surfactant-assisted hydrothermal reaction. Secondly, the precursor is uniformly mixed with the lithium salt and ammonium metavanadate in the solution. Experienced drying and sintering processes, the LNCM cathode material uniformly coated with V2O5 is achieved. The electrochemical test results show that the discharge specific capacity of LNCM cathode material coated with 2 wt% V2O5 reaches 101.7 mAh ·g−1 at 10 C, and the capacity retention rate has 89.12% after 100 cycles at 0.5 C. Both of the novel synthetic method and the coating effect of V2O5 reduce electrolyte side reaction on the LNCM cathode material, and accelerate Li+ diffusion rate, then further derive more desirable electrochemical properties.

Spherical abrasives were employed to polish the growing deposited layer during nickel electroforming process. On a translational flat cathode, nickel deposits with distinct polishing mark were obtained. It was found that the abrasive polishing can help to improve the microstructure and increase the mechanical properties of the nickel deposits. Compared with the deposits prepared with traditional method, the microstructure became more homogeneous and the microhardness increased nearly two times. The increase of current density led to coarse structure and lower microhardness.

An air-stable (pi-allyl)iridium complex derived from naphthocyclooctatetraene and a phosphoramidite ligand has been synthesized and found to be highly efficient in iridium-catalyzed allylic substitution reactions. This catalyst features excellent regiosel

Potassium zinc phosphate(KZnPO4) was synthesized by solid-state reaction using K3PO4·3H2O and ZnSO4·7H2O as reagents.Experimental project was designed by uniform design and data mining technology.The obtained product was characterized by X-ray diffraction,scanning electron microscope and energy disperses spectroscopy,and its property of long lasting phosphorescence was also studied.Based on the yield and zinc content,two mathematical models were established by regression analysis.The best technology conditions of synthesis can be obtained by optimization of these two models.Under the optimum reaction conditions: molar ratio of n(K3PO4·3H2O)∶n(ZnSO4·7H2O)=1.01,grinding time 31 min,holding temperature 750 ℃,holding time 3.2 h,the prepared product is KZnPO4 with nano-lamellar structure.After ultraviolet radiation,the obtained product show blue-green long lasting phosphorescence and the highest emission peak is located at 415～530 nm.

This study examined the effect of neuron-endothelial coupling on the survival of neurons after ischemia and the possible mechanism underlying that effect. Whole-cell patch-clamp experiments were performed on cortical neurons cultured alone or directly cocultured with brain microvascular endothelial cells (BMEC). Propidium iodide (PI) and NeuN staining were performed to examine neuronal death following oxygen and glucose deprivation (OGD). We found that the neuronal transient outward potassium currents (IA) decreased in the coculture system, whereas the outward delayed-rectifier potassium currents (IK) did not. Sodium nitroprusside, a NO donor, enhanced BMEC-induced IA inhibition and nitro-l-arginine methylester, a NOS inhibitor, partially prevented this inhibition. Moreover, the neurons directly cocultured with BMEC showed more resistance to OGD-induced injury compared with the neurons cultured alone, and that neuroprotective effect was abolished by treatment with NS5806, an activator of the IA. These results indicate that vascular endothelial cells assist neurons to prevent hypoxic injury via inhibiting neuronal IA by production of NO in the direct neuron-BMEC coculture system. These results further provide direct evidence of functional coupling between neurons and vascular endothelial cells. This study clearly demonstrates that vascular endothelial cells play beneficial roles in the pathophysiological processes of neurons after hypoxic injury, suggesting that the improvement of neurovascular coupling or functional remodeling may become an important therapeutic target for preventing brain injury.

A simple synthesis method namely solvent displacement crystallization was used to prepare zinc phosphate, and obtained product was characterized by X-ray diffraction, scanning electron microscope and chemical analysis. The corrosive effectiveness of title zinc phosphate was evaluated by electrochemical impedance of two coatings immersion test. The results show that the obtained product is a highly crystalline, micronized and layered zinc phosphate. Comparing with commercial zinc phosphate, the synthesized layered microcrystalline product has excellent anticorrosive property in alkyd or epoxy coatings.

The electrochemical corrosion inhibitions of potassium zinc phosphate were studied by polarization, open circuit potential measurements, electrochemical impedance of the pigment extract and coating immersion test. Dynamic analysis shows that in pH=7 3.5% NaCl extract, KZn2(PO4)(HPO4) functions as a cathodic inhibitor on steel and its efficiency is even superior to other phosphates. The inhibiting efficiency of the pigments on steel decrease in the order: KZn2(PO4)(HPO4) > aluminum zinc phosphate > zinc phosphate ≧ aluminum triphosphate The coating tests show that potassium zinc phosphate can efficiently enhance the inhibition properties of coating and prevent the erosion of the corrosive medium by improving the barrier and hydrophobicity of the coating. The anticorrosive property of the pigments decrease in the order: KZn2(PO4)(HPO4)> aluminum zinc phosphate > zinc phosphate ≈APW-1.

A new synthesis method namely hydrolysis precipitation was used to prepare Zn3(PO4)2•4H2O. Structural characteristics of products were investigated by X-ray Diffraction, scanning electron microscope and chemical analysis. The electrochemical corrosion inhibitions of title zinc phosphate were studied by electrochemical impedance of coating immersion test. The results show that the obtained product is a highly crystalline, micronized and lamellar Zn3(PO4)2•4H2O. Comparing with commercial zinc phosphate, the synthesized lamellar microcrystalline product has excellent anticorrosive property and dispersibility.

Both water decoction method and ultrasonic-assisted method were used to compare the extraction efficiency during the extraction of flavonoids from honeysuckle leaves. Three dynamic models were adopted in study of the extraction dynamics. The results show that the ultrasonic wave strengthening can improve the extraction efficiency of flavonoids comparing water decoction method in the experimental conditions. The ultrasonic wave strengthening extraction dynamic equation agrees with , while the water decoction method extraction dynamic equation agrees with .

The Schiff base-containing pendant monoaza crown ether HL1, HL2, HL3 and HL4 have been synthesized by condensation of salicylaldehyde with N-(4-aminoaryl) monoaza crown ethers, which were prepared conveniently from 4-nitro-N, N-di(hydroxyethyl) aniline or 4-nitrobenzyl chloride via cyclization or condensation and reduction. The structures of HL1—HL4 were verified by 1H NMR, IR spectra, MS and elemental analysis. Moreover, the oxygenation constants (KO2) and thermodynamic parameters (δH0 and δS0) of their cobalt(II) complexes were determined in the range of −5 °C to 25 °C, and the effect of crown ring bonded to a Schiff base on the dioxygen affinities of cobalt(II) complexes was also observed as compared to the uncrowned analogue (CoL).

The first enantioselective total synthesis of (-)-8-deoxyserratinine has been achieved in 15 steps from enone 4 with 7% overall yield. The key features include a highly efficient Helquist annulation to furnish the cis-fused 6/5 bicycle, facile construction of the aza nine-membered ring system employing double N-alkylation strategy, as well as asymmetric Shi epoxidation, delivering the desired beta-epoxide stereospecifically.

A novel heterobimetallic La-Na coordination polymer [La2(odpa)2Na2(H2O)3]n (H4odpa= 2,2′,3,3′ -oxydiphthalic acid) was synthesized under mild condition and characterized by single-crystal X-ray diffraction. Its X-ray crystal structure shows that the new coordination polymer belongs to a monoclinic system, C2/c space group. The crystallographic data are: a = 31.451(2) A, b = 12.635(5) A, c= 8.986(7) A, α = γ = 90°, β = 102.54(8)°. In this complex, it presents a three-dimensional structure containing a 1D {LaO9} chain and 2D Na-odpa layer, which have not been reported in all coordination polymers of odpa ligand.

Manganese oxides nanofibers were successfully fabricated by, an electrospinning method and its electrochemical behavior was investigated as three-dimensional (3D) architecture of cathodic materials. Scanning electron microscope, X-ray diffraction and the discharge/charge curves were used to characterize their structures and electrochemical properties. Manganese oxides nanofibers are achieved after calcination at 450 degrees C. The high reversible discharge capacity reaches 160mAh/g and the discharge capacity is about 132.5mAh/g with capacity loss less than 1.0% per cycle in 50 cycling. SEM observations show that the structure of manganese oxides nanofibers is stable without the mechanical destruction of nanofibers during the Li(+) ion intercalation and deintercalation. The results demonstrate that manganese oxides nanofibers are promising cathodic materials for 3D lithium batteries.

In the current work, a rapid, simple, and sensitive inductively coupled plasma mass spectrometry (ICP-MS) method for determining vitamin B12 in pharmaceutical preparations is proposed. The calibration graph plotted with five concentrations of vitamin B12 was linear with a regression coefficient r2 = 0.9994. The detection limit was 0.05 ng/mL for vitamin B12. At a pump rate of 30 rpm, an analysis cycle of vitamin B12, including sampling and washing, could be accomplished in 0.5 min with the relative standard deviations of 4.2%, 3.5%, and 2.6% for 0.25 ng/mL, 2.5 ng/mL, and 25 ng/mL, respectively. The method has been applied successfully in the determination of vitamin B12 in multivitamin tablets.

BACKGROUND To date, there have been no reports on altered nitric oxide (NO) content in ischemia/reperfusion with regard to in vivo preconditioning procedures. These studies are important for understanding the mechanisms of NO during early myocardial ischemic preconditioning. The aim of the present study was to investigate the mechanisms of NO during early myocardial ischemic preconditioning by measuring levels of NO and cyclic guanosine monophosphate (cGMP), as well as activity of nitric oxide synthase (NOS) in ischemia/reperfusion with respect to preconditioning in rats. METHODS Sixty-six female Sprague-Dawley rats were randomly divided into four groups: ischemic preconditioning group (IP), ischemia/reperfusion group (I/R), control group (CON), and preconditioning procedure group (PC). In the PC group, rats were further divided into PC1-, PC1 +, PC2-, PC2 +, PC3-, and PC3 + subgroups. Rats underwent left coronary artery occlusion and reperfusion, and subsequently, NOS activity and levels were assessed with spectrophotometric analysis. cGMP contents were measured with radioimmunoassay. RESULTS The level of NO and cGMP, as well as the activity of NOS, were significantly higher in the IP group compared to the I/R and CON groups (P < 0.05). During preconditioning prior to prolonged ischemia, NO and cGMP levels varied markedly with ischemia and reperfusion. The levels of NO repeatedly increased when the heart was exposed to three episodes of 5-minute ischemia, and were almost completely reversed during each reperfusion period. NO and cGMP levels were significantly different between the 5-minute period of ischemia and the same period of reperfusion during preconditioning. CONCLUSIONS NO plays an important role during early phase myocardial ischemic preconditioning in rats. NO and cGMP could be triggers and mediators of early phase myocardial ischemic preconditioning. Altered NOS activity following ischemic stress could be the primary inducer of higher NO levels detected. NO and cGMP fluctuations might be the trigger for protection during early phase myocardial ischemic preconditioning.

In order to improve the nitrogen removal efficiency and save operational cost, the feasibility of the alternating aerobic-anoxic process (AAA process) applied in a sequencing batch reactor (SBR) system for nitrogen removal was investigated. Under sufficient influent alkalinity, the AAA process did not have an advantage over one aerobicanoxic (OAA) cycle on treatment efficiency because microorganisms had an adaptive stage at the alternating aerobic-anoxic transition, which would prolong the total cycling time. On the contrary, the AAA process made the system control more complicated. Under deficient influent alkalinity, when compared to OAA, the AAA process improved treatment efficiency and effluent quality with NH4 +-N in the effluent below the detection limit. In the nitrification, the average stoichiometric ratio between alkalinity consumption and ammonia oxidation is calculated to be 7.07 mg CaCO3/mg NH4 +-N. In the denitrification, the average stoichiometric ratio between alkalinity production and NO3 −-N reduction is about 3.57 mg CaCO3/mg NO3 −-N. As a result, half of the alkalinity previously consumed during the aerobic nitrification was recovered during the subsequent anoxic denitrification period. That was why the higher treatment efficiency in the AAA process was achieved without the supplement of bicarbonate alkalinity. If the lack of alkalinity in the influent was less than 1/3 of that needed, there is no need for external alkalinity addition and treatment efficiency was the same as that under sufficient influent alkalinity. Even if the lack of alkalinity in the influent was more than 1/3 of that needed, the AAA process was an optimal strategy because it reduced the external alkalinity addition and saved on operational cost.

Highly potent DPP-4 inhibitors have been identified by hybrid compound design based on linagliptin and alogliptin. The most promising compound 2h (IC50 = 0.31 nM) exhibited 8.5-fold and 2.5-fold more potent activity than that of alogliptin (IC50 = 2.63 nM) and linagliptin (IC50 = 0.77 nM), respectively. Compound 2h had a good inhibition selectivity for DPP-4 over DPP-8/9 and thus was selected for further biological evaluation, including oral glucose tolerance, plasma DPP-4 inhibitory activity, pharmacokinetic profile, acute toxicity and hERG inhibition. The assay results showed that 2h displayed significant in vivo glucose-lowering effect and low risk of toxicity. Further studies are expected to confirm 2h as a potential drug candidate for the treatment of type 2 diabetes.

An air-stable (pi-allyl)iridium complex derived from naphthocyclooctatetraene and a phosphoramidite ligand has been synthesized and found to be highly efficient in iridium-catalyzed allylic substitution reactions. This catalyst features excellent regiosel

In order to obtain the extraction dynamics of mogroside from grosvenori momordica by ultrasonic wave strengthening, two dynamics model were used to evaluate this process and the extraction efficiency. The results show that the ultrasonic wave strengthening can improve the extraction efficiency of mogroside in the experimental conditions. The ultrasonic wave strengthening extraction dynamics equation agrees with the dynamic equation In C = γ In t + λ. Under the high frequency of ultrasound extraction or high temperature or long extraction time, the extraction process will not be controlled by the dynamic. In order to achieve the medicinal compositions with high activity and stability, the frequency, temperature and duration of ultrasonic extraction should be controlled in a certain range.

The strategy is general and can be applied to the preparation of many complex members of the Lycopodium family.

Ornithine decarboxylase (ODC), the key enzyme of polyamine biosynthesis, has paradoxical roles in apoptosis. Our published papers show overexpression of ODC prevents the apoptosis induced by many cytotoxic drugs. Thapsigargin (TG) is an inhibitor of the sarcoplasmic/endoplasmic reticulum (ER) Ca(2+) ATPase (SERCA) pumps and causes ER stress-induced apoptosis. We used ODC overexpressing cell lines to examine whether overexpression of ODC inhibits TG-induced apoptosis. Our results indicated overexpression of ODC attenuated TG-induced apoptosis. Overexpression of ODC blocked procaspase-4 cleavage and phosphorylation of protein kinase-like ER-resident kinase (PERK), triggered by TG. It also attenuated the increase in CAAT/enhancer binding protein homologous protein (CHOP). Cells with overexpressed ODC had greater Bcl-2 expression. Overexpression of ODC preserved the expression of Bcl-2, inhibited the increase in Bak and stabilized mitochondrial membrane potential without the influences of TG. Cytochrome c release and down-stream caspase activation were blocked. That is, overexpression of ODC inhibits the mitochondria-mediated apoptotic pathway, induced by TG. Finally, overexpression of ODC maintains the protein and mRNA expression of SERCA. In conclusion, overexpression of ODC suppresses TG-induced apoptosis by blocking caspase-4 activation and PERK phosphorylation, attenuating CHOP expression and inhibiting the mitochondria-mediated apoptotic pathway.

From the viewpoint of high-temperature energy transportation, a fundamental study of a chemical heat pipe which uses the SO2 /SO3 reversible thermochemical reaction is carried out in a closed system consisting of exothermic and endothermic reactors.For a relatively wide range of circulating gas flow rate, the gas composition, and initial temperature of the catalyst fixed bed, it is found that SO2 and SO3 of nearly equilibrium concentration could be circulated between the SO2-oxidation and the SO3-deoxidization reactors. Further, the possibility of continuous thermal energy transportation by use of this system was determined. The heat transportation characteristics of the system is made clear by the relationship between the heat flux released from the catalyst fixed bed and the molal velocity of SO2.

Based on density functional theories, we have investigated the nanostructure in which boron and nitrogen co-doped carbon nanotube (CNT)/graphene (GR) were connected by an oxygen molecular. The geometry structure and electronic properties of the system were calculated carefully. The band structures indicate that the impurity state of oxygen transfer the semiconducting co-doped carbon nanotube/graphene into a semimetallic composite material. The results show that the connection can be achieved with energy release under a wider range of distance between the nanotube and graphene. It indicates that the connection between the nanotube and the graphene might be a self-assemble process.

牛血清アルブミン (BSA) 溶液のデッドエンド限外濾過において膜面上に堆積するタンパク質層を観察し, 膜面傾斜型濾過では堆積ケーク層が膜面下方に形成されることを明らかにした.膜面傾斜型濾過に引き続き下向流濾過を行うと堆積ケーク層は膜面上の全体に広がり, 全濾過抵抗Rtは著しく増大した.同一の濾液量で比較すると, 膜面傾斜型濾過に引き続き下向流濾過を行った場合とはじめから下向流濾過を行った場合のRt値は一致した.

Monolayers of tungsten disulfide doped with atomic vacancies have been investigated for the first time by density functional theory calculations. The results reveal that the atomic vacancy defects affect the electronic and optical properties of the tungsten disulfide monolayers. The strongly ionic character of the W-S bonds and the non-bonding electrons of the vacancy defects result in spin polarization near the defects. Moreover, the spin polarization of single W atomic vacancies has a larger range than for one or two S atomic vacancies. In particular, increased intensity of absorption and red shift of optical absorption are universally observed in the presence of these atomic defects, which are shown to be a fundamental factor in determining the spin transport and optical absorption of tungsten disulfide monolayers.

Polycrystalline perovskite SrMn0.5Fe0.5O3 has been synthesized by solid state reaction method. The crystal structure, magnetic properties and valence states of Mn and Fe ions have been investigated. X ray diffraction (XRD) and subsequent Rietveld refinement confirmed that SrMn0.5Fe0.5O3 is found to be a primitive cubic crystal structure，Mn and Fe atoms randomly occupy the center of oxygen octahedron. Also with the measure of XPS which indicates that Mn ions show trivalent and tetravalent state, while Fe ions are in trivalent state. Paramagnetic phase was observed in high temperature (>230 K), the spin-glass behavior at low temperature (3+ ions located in the octahedral sites.