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Purpose: We developed a contrast agent for targeting E-selectin expression. We detected the agent using magnetic resonance imaging (MRI) in vivo in nude mice that had undergone nasopharyngeal carcinoma (NPC) metastasis. Methods: Sialyl Lewis X (sLeX) was conjugated with ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles. Hydrodynamic size, polydispersity index, and ζ-potential of USPIO-polyethylene glycol (PEG) nanoparticles and USPIO-PEG-sLeX nanoparticles were measured. Component changes in nanoparticles of USPIO, USPIO-PEG, and USPIO-PEG-sLeX were analyzed by thermogravimetric analysis and Fourier-transform infrared spectroscopy. A model of NPC metastasis to inguinal lymph nodes in nude mice was used to investigate characteristics of the USPIO-PEG-sLeX nanoparticles in vivo. We investigated the ability of the T2* value, change in T2* value (ΔT2* value), and enhancement rate (ER) to assess accumulation of USPIO-PEG-sLeX nanoparticles quantitatively in mice of a metastasis group and control group. Four MRI scans were undertaken for each mouse. The first scan (t0) was done before administration of USPIO-PEG-sLeX nanoparticles (0.1 mL) via the tail vein. The other scans were carried out at 0 (t1), 1 (t2), and 2 hours (t3) postinjection. The mean optical density was used to reflect E-selectin expression. Results: sLeX was labeled onto USPIO successfully. In vivo, there were significant interactions between the groups and time for T2* values after administration of USPIO-PEG-sLeX nanoparticles. Six parameters (T2* at t2, ΔT2* at t1, ΔT2* at t2, ER at t1, ER at t2, and ER at t3) were correlated with the mean optical density. Conclusion: USPIO-PEG-sLeX nanoparticles can be used to assess E-selectin expression quantitatively. Use of such molecular probes could enable detection of early metastasis of NPC, more accurate staging, and treatment monitoring.

The thermodynamic estimation and experimental research on a laboratory scale with different fluxing agents (silica, K-feldspar) in yellow phosphorus production by the electric furnace method were investigated. The thermodynamic calculation showed that the reaction temperature of silica system is 1120°C, while the temperature dropped to 970°C with K-feldspar as a fluxing agent. The production efficiencies of phosphorus and potassium from this process were investigated and different reaction times and temperatures were studied. The experimental results demonstrated that the phosphorus conversion rates of the Ca5(PO4)3F-C-silica and Ca5(PO4)3F-C-KAlSi3O8 systems reached 96.9% and 99.0%, respectively. The potassium gasification rate of the Ca5(PO4)3F-C-KAlSi3O8 system reached 44.3%. The characteristic of slag was studied by flow temperature and viscosity experiments, and the flow temperature was reduced by 61°C, the residual viscosity was clearly increased. Finally, the mechanisms of yellow phosphorus production with different fluxing agents were analyzed by XRD, SEM and TEM methods.

The corrosion resistance in medium carbon high-strength spring steel was investigated in neutral salt spray of 5% NaCl solution and potentiodynamic polarisation measurements. The results showed tha...

The consumption of ore and electricity for the production of yellow phosphorus is enormous in an electrical furnace. To reduce consumption and conserve energy, various fluxing agents, e.g., SiO2, K...

As an inherited disorder caused by initial death of rod photoreceptors, retinitis pigmentosa is currently untreatable and usually leads to partial or complete blindness. (2R, 3S)-Pinobanksin-3-cinnamate (PC) is a new flavonone isolated from the seed of Alpinia galanga Willd, and has been reported to exert neuroprotective effects by upregulating endogenous antioxidant enzymes. In this study, the anti-oxidative and neuroprotective activity of PC against photoreceptor apoptosis in rd10 mouse model of retinitis pigmentosa was explored. PC showed to produce significant improvement in histology and function in rd10 mice through reducing oxidative stress. For the first time, the protective effects of PC were demonstrated against retina degeneration in rd10 mice and our study provides scientific rationale on using PC as the supplementary treatment to the outer retina diseases, including retinitis pigmentosa, in which oxidative stress is thought to contribute to disease progression.

The glucocorticoid receptor (GR), a transcription factor regulating gene expression in a ligand-dependent fashion, is known for flexibility in adapting various ligands with their structures ranging from steroid to non-steroid. However, in our previous study (Chen et al., 2011), GR shows a stringent discrimination against a set of steroid ligands with highly similar structures for triggering its nuclear migration. In order to resolve this puzzle, we employed molecular docking simulations to investigate the origin of this structural discrimination. By analyzing the docking orientations and the related ligand-GR interaction patterns, we found that the hydrophilicity mismatch between the docking ligand and the GR ligand-binding site is the main cause combined with the steric hindrance and structural rigidness of these steroid ligands. Furthermore we utilized this knowledge to rationalize how the structure-binding interaction of non-steroid ligands triggers GR nuclear migration with their structures available in Protein Data Bank.

The isothermal crystallisation of polyethylene (PE) chains around single PE lamella in vacuum is investigated by molecular dynamic simulation. The crystallisation process is analysed in terms of the orientational order parameters, principal moments of inertia for the simulated systems. The effects of charge interactions between the polymer chains and lamella are discussed. It is found that the crystallisation process for uncharged systems can be divided into three stages: (1) adsorption, (2) orientation and (3) arrangement. The single polymer lamella changes a little during the three stages. PE chains are arranged parallel to the chain direction of the stems in the crystalline state. When considering the effect of charge interactions between the polymer chains and lamella, a different crystallisation process appears. The single polymer lamella is affected by the charged polymer chains.

Calmodulin (CaM), the primary intracellular Ca(2+) receptor, regulates a large number of key enzymes and controls a wide spectrum of important biological responses. Recognition between CaM and its target sequence in rat olfactory cyclic nucleotide-gated ion channel (OLFp) was investigated by circular dichroism (CD), fluorescence, and NMR spectroscopy. Fluorescence data showed the OLFp tightly bound to CaM with a dissociation constant of 12 nM in a 1:1 stoichiometry. Far-UV CD data showed that approximately 60% of OLFp residues formed α-helical structures when associated with CaM. NMR data showed that most of the (15)N-(1)H HSQC cross-peaks of the (15)N-labeled CaM not only shifted but also split into two sets of peaks upon association with the OLFp. Our data indicated that the two distinct CaM/OLFp complexes existed simultaneously with stable structures that were not interexchangeable within the NMR time scale. In light of the palindromic sequence of OLFp (FQRIVRLVGVIRDW) for CaM targeting, we proposed that the helical OLFp with C2 symmetry may bind to CaM in two orientations. This hypothesis is supported by the observation that only one set of (15)N-(1)H HSQC cross-peaks of the (15)N-labeled CaM was detected upon association with OLFp-M13 chimeric peptide (OLFMp), a mutated OLFp lacking the palindromic feature. The binding specificity of OLFMp to CaM was restored when the palindromic feature was destroyed. Binding modes of CaM/OLFp and CaM/OLFMp simulated by molecular docking were in accord with their distinct patterns observed in HSQC spectra. Our studies suggest that the palindromic residues in OLFp are crucial for the orientation-specific recognition by CaM.

A rapid and comprehensive ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) method was developed for simultaneous determination of 10 major bioactive constituents in Mailuoning injection. Within 15 min, chromatographic separation was achieved on an Acquity UPLC BEH C18 column (50 mm × 2.1 mm I.D.) packed with 1.7 μm particles by a linear gradient elution. The analytes were monitored in a selected-ion reaction (SIR) mode with the electrospray ionization interface by the following ions: m/z 353.4 for isomers of chlorogenic acid, m/z 515.4 for isomers of 1,3-dicaffeoylquinic acid, m/z 179.2 for caffeic acid, m/z 192.9 for ferulic acid, m/z 503.2 for ecdysterone, and m/z 147.1 for cinnamic acid, respectively. The calibration curves of all analytes revealed good linear regression (r2 ≥ 0.9983) within test ranges. This method provided excellent sensitivity with LOQ and good precision with RSDs of intra- and interday variation less than 1.26% and 2.27%, respectively. The validated met...

The thiol-terminated β-cyclodextrin derivative (β-CDd) was attached to the surface of a gold electrode of quartz crystal resonator by self-assembly. The inclusion reactions of benzene derivatives and naphthalene derivatives with β-CDd were monitored in situ by using a quartz crystal microbalance (QCM). The influences of temperature, concentration, the number of substituting groups, and their positions on an aromatic ring on the inclusion constant and the rate constant were investigated. The results indicated that the stoichiometry of the inclusion complexes formed is 1:1 for the host β-CDd with various guest benzene derivatives and naphthalene derivatives, and the kinetics of their formation were fitted for the Langmuir adsorption equation. The β-CDd has good selective recognition ability as to the molecular volume, the number of substituting groups, and their positions on an aromatic ring of guest.

In this study, a rapid and comprehensive ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) method was developed for simultaneous determination of nine major bioactive constituents in Dengzhanxixin injection. The chromatographic separations were obtained on an Acquity UPLC BEH C18 column (50 mm × 2.1 mm I.D., 1.7 μm) by a linear gradient elution with the mobile phase consisting of A (water and 0.6% acetic acid) and B (acetonitrile and 0.6% acetic acid). The total analytical run time was relatively short (14 min). The analytes and two internal standards (ISs) were all monitored in a selected-ion reaction (SIR) mode with a negative electrospray ionization (ESI−) interface. The calibration curves of all analytes revealed good linear regression (r2 ≥ 0.9972) within test ranges. This method provided good precision with RSD of intra- and interday variation less than 1.26% and 2.51%, respectively. The validated method was then applied to quantify the nine major constituents in six batc...

High-speed counter-current chromatography was successfully applied to separate and purify bioactive ingredients from sweet potato leaves. Four caffeoylquinic acid derivatives and a mixture of two flavonoids were successfully obtained in one step. The caffeoylquinic acid derivatives were 3-O-caffeoylquinic acid (1), 4,5-di-O-caffeoylquinic acid (4), 3,5-di-O-caffeoylquinic acid (5), and 3,4-di-O-caffeoylquinic acid (6). The two-phase solvent system was composed of n-hexane\ethyl acetate\ethanol\water\acetic acid (1:5:2:4:0.1, v/v). The upper layer was used as the stationary phase, and the lower layer was used as the mobile phase. The flow rate was 1.5 mL/min, the revolution speed was 850 rpm, and the injection volume was 280 mg. The mixture of flavonoids was separated by preparative high-performance liquid chromatography into quercetin-3-O-β-D-galactopyranoside (2) and quercetin-3-O-β-D-glucoside (3). The purities of compounds 1–6 were 95.8% (5.4 mg), 99.5% (6.1 mg), 98.7% (15.1 mg), 97.8% (14.5 mg), 96.2%...

2-Methylresorcinarene and its methylene-bridged cavitand derivative as host compounds were investigated in selective complexation of alkali metal ions as guests in methanol media by photoluminescence measurements. These host molecules possess either flexible (2-methylresorcinarene) or rigid (cavitand) molecular skeleton. The Benesi–Hildebrand method and the van't Hoff theory have been applied to determine the stability constants and the thermodynamic parameters, respectively. Considerable interactions between 2-methylresorcinarene and Li+ or Na+ ions have been observed while the rigid cavitand derivative can interact only with K+ or Cs+ ions. Neither the complexes of 2-methylresorcinarene with K+ or Cs+ nor those of the cavitand derivative with Li+ or Na+ ions are stable at room temperature in methanol media. Quantum-chemical investigations justified that only solvated Li+ and Na+ ions can form stable complexes with 2-methylresorcinarene while unsolvated K+ and Cs+ ions form stable complexes with the meth...

An energetic cuprous azide complex, [Cu2(2apyz)(N3)2] n (1) (2apyz = 2-aminopyrazine), has been synthesized through hydrothermal method by utilizing the reducibility of H3PO3 and structurally characterized by single-crystal X-ray diffraction. Complex 1 has a 2-D layer structure constructed from copper(I) bridged by azide and pyrazine. Catalysis research shows 1 can promote the burning rate of the main component of rocket propellant.

A coordination polymer, [Co(2-mpac)2(4,4′-bpy)·(4,4′-bpy)] n (2-mpac: 5-methyl-2-pyrazinecarboxylic acid; 4,4′-bpy: 4,4′-bipyridine), has been synthesized through hydrothermal synthesis and structurally characterized by X-ray single crystal diffraction. Single crystal X-ray diffraction analysis reveals a 3-D network featuring a 1-D tunnel filled with 4,4′-bpy molecules. Elemental analysis, IR, thermogravimetric analysis, and magnetic properties are presented.

Chitosan derivatives, such as chitosan alpha-ketoglutaric acid (KCTS) and hydroxamated chitosan alpha-ketoglutaric acid (HKCTS), are prepared and their coordination behavior toward Ca(II) was studied. The adsorption isotherms were correlated by dc/dt = −kcn at 20°C, 30°C, 40°C, 50°C, and 60°C. By linear correlation, the shapes of the isotherm curves were similar to the kinetic function of 1/c = kt and the rate equation was dc/dt = −kc 2; the activation energies were 13.31 and 14.76 kJ mol−1 for KCTS and HKCTS, respectively. The overall rate of Ca(II) adsorption is likely to be controlled by the chemical process. The coordination mechanism of chitosan derivatives with Ca(II) was studied by infrared and X-ray photoelectron spectroscopy. The results indicated that –NH– of KCTS was coordinated. Nitrogen of amino, oxygens of hydroxamic acid, and carbonyl in HKCTS coordinated with Ca(II).

A diblock copolymer of polystyrene–block–poly(2-hydroxyethyl acrylate) (PS-b-PHEA) was synthesized via atom transfer radical polymerization (ATRP) and reacted with cinnamoyl chloride in triethylamine to yield PS-b-(PCEA-co-PHEA) copolymer with photo-cross-linkable poly(2-cinnamoylethyl acrylate) (PCEA) moieties. Then the triblock copolymer of polystyrene–block–poly(2-cinnamoylethyl acrylate-co-2-hydroxyethyl acrylate)–block–poly(γ-methacryloxypropyltrimethoxysilane) (PS-b-(PCEA-co-PHEA)-b-PMPS) was synthesized viaATRP from PS-b-(PCEA-co-PHEA) copolymer. Using as-prepared triblock copolymer as a macromolecular coupling agent to modify glass fibers, via microbond tests, the interfacial bond strength between pretreated glass fiber and polystyrene was compared before and after copolymer photo-crosslinking. The partially crosslinked block copolymer coupling agent greatly improved the interfacial adhesion of glass fiber-reinforced polystyrene.

Utilizing Co(2-mpac)2(H2O)2 as molecular building block, a coordination polymer, [Co2(2-mpac)4(4,4′-bpy) · 2H2O] n (1) (2-mpac = 5-methyl-2-pyrazinecarboxylic acid; 4,4′-bpy = 4,4′-bipyridine), was synthesized and structurally characterized by X-ray single crystal diffraction. Elemental analysis, infrared, and magnetism are presented. Variable temperature magnetic susceptibility measurements exhibit weak antiferromagnetic interaction between Co centers in 1.

Two pyrazole-based polydentate ligands, 1,3-bis(5-methyl-3-phenylpyrazol-1-yl)-propan-2-ol (Hmppzpo) and 1,3-bis(5-methyl-3-p-isopropylphenylpyrazol-1-yl)-propan-2-ol (Hmcpzpo), have been synthesized. A third ligand, 1,3-bis(3,5-dimethylpyrazol-1-yl)-propan-2-ol (Hdmpzpo), has been synthetically modified. Seven new M(II) coordination compounds of general formula M2L2X2 (M = Zn, Ni; X = NO3 or ClO4; L = dmpzpo, mppzpo or mcpzpo) or MLX (M = Pd; L = dmpzpo; X = Cl) were synthesized and structurally characterized by elemental analysis and FT-IR analysis. The crystal structures of [Zn2(μ-dmpzpo-O,N,N′)2(NO3)2] · 2H2O (1 · 2H2O), [Ni2(μ-dmpzpo-O,N,N′)2(CH3CN)2](ClO4)2 (2) and Pd(μ-dmpzpo-N,N′)Cl2 (4) were determined by single-crystal X-ray crystallography. The crystal structures show that complexes 1 · 2H2O and 2 are center-symmetric dinuclear compounds, with two metal ions bridged by two alkoxo groups and each metal ion with a distorted square-pyramidal environment. The palladium complex, 4, displayed square-...

Six complexes, rubidium and cesium 3,5-dinitropyrid-2-onate (2DNPO), 3,5-dinitropyrid-4-onate (4NDPO), 3,5-dinitropyrid-4-one-N-hydroxylate (4DNPNO), were synthesized and characterized by elemental analysis, FT-IR, TG-DTG and X-ray single-crystal diffraction analysis. All the complexes crystallized from water and one of them was a hydrate. Rubidium 3,5-dinitropyrid-4-one-N-hydroxylate was crystallized with the 1 : 2 stoichiometry as Rb[H(4DNPNO)(2)] upon absorption of carbon dioxide. The structural determinations showed that the coordination sphere around a metal centre is made up of oxygen atoms and nitrogen atoms, except for the 4DNPNO complexes, where the coordination sphere accommodates exclusively oxygen atoms. The coordination numbers of the metal centers vary from 8, 10, 11 to 12, while the ligands, each employing its pyridone tautomer, link with metal cations. Bridging oxygen atoms play an important role in construction of two- and/or three-dimensional networks of these complexes. Hydrogen bonding contributes to the connectivity within a given sheet in Rb[H(4DNPNO)(2)]; aromatic - stacking interactions exist only in Cs(4DNPNO). The interactions between metal atoms and ligands are generally very weak. The organization of all layer structures appears to be governed mainly by steric effects and electrostatic forces with very little directional influence of the cations. The thermogravimetric analyses of these complexes showed the following consecutive processes: loss of NO(2) groups, collapse of the pyridyl ring backbones and finally inorganic residue formation. These complexes could be used as probes in template effects of heavy alkali-metal cations in the organization of biorelevant ligands and as environment-friendly energetic catalysts in solid propellants.

Mashing for the determination of malt extract and wort quality factors is one of the most fundamental analyses performed in malting and brewing laboratories. The origins of the Congress mash method...

The concentration of six organic acids (acetic acid, lactic acid, pyruvic acid, malic acid, citric acid, and succinic acid) and pH were determined in 45 beer samples (23 from China and 22 from othe...

Organic acids in malt play an important role in determining the pH and buffering capability of wort. The organic acids content of commercial malts and factors influencing this content were investig...

Some selected surfactants and alcohols were examined for their effects on γ-cyclodextrin glucanotransferase (γ-CGTase) production by Bacillus macorous WSH02-06. Both Tween 60 and n-Propyl alcohol had the ability to increase γ-CGTase yield about 1.7-fold. The investigation of fatty acid composition demonstrated that the addition of Tween 60 greatly increased the ratio of unsaturated to saturated fatty acids in cell membrane lipids, while n-propyl alcohol interfered with the proportion among unsaturated fatty acids. Study of the γ-CGTase fermentation in 5-L fermentor revealed that the addition of n-propyl alcohol improved the specific production rate and the yield of γ-CGTase.

Response surface methodology was employed to study the effects of endoxylanase concentration, wort pH, and Ca2+ concentration on the degradation of arabinoxylans in mashing with grist containing wh...

The production of γ-cyclodextrin glucanotransferase (γ-CGTase) from Bacillus macorous WSH02-06 was optimized in shake flasks using conventional sequential techniques and statistical experimental design. Effects of nutrients including carbon and nitrogen sources, cation ions, initial pH, and temperature on γ-CGTase production were investigated. Corn starch, peptone, Mn2+, and Zn2+ were found to be essential for obtaining high γ-CGTase activity and biomass. The promoting effect of manganese and zinc on enzyme production has not been reported previously. According to the results of orthogonal array experiment, the optimal culture medium for high γ-CGTase activity was determined. Maximal γ-CGTase activity obtained in the optimized culture broth was about 250 U/mL which was 10-fold higher than that obtained in the basal medium. Time course of cell growth and γ-CGTase production in a 7 l fermenter showed that enzyme production was growth associated, and that maximum γ-CGTase activity reached 277 U/mL i...

The objective of this research work was to develop a new high-throughput screening method for lipoxygenase (LOX) activity, which was based on the determination of lipid hydroperoxides by ferrous oxidation-xylenol orange (FOX) assay. The final method employed extraction of a finely ground sample at a grist/buffer ratio of 1:20 for 30 min at 4°C. Extracts were incubated with linoleic acid for 5 min at 25°C, and the hydroperoxides formed were determined with the FOX reagent. Up to 100 samples can be analyzed per day with this method. The new method showed good reproducibility (coefficient of variation = 1.4―6.5%) and accuracy, although there are some disadvantages and limitations compared with the traditional UV assay. The FOX assay principal may be useful to barley breeders for screening large numbers of progeny, and also would have value to maltsters and brewers when conducting research work on LOX or performing routine quality assurance.

6-[3-(1-Adamantyl)-4-hydroxyphenyl]-2-naphthalene carboxylic acid (AHPN or CD437), originally identified as a retinoic acid receptor gamma-selective retinoid, was previously shown to induce growth inhibition and apoptosis in human breast cancer cells. In this study, we investigated the role of AHPN/CD437 and its mechanism of action in human lung cancer cell lines. Our results demonstrated that AHPN/CD437 effectively inhibited lung cancer cell growth by inducing G0/G1 arrest and apoptosis, a process that is accompanied by rapid induction of c-Jun, nur77, and p21(WAF1/CIP1). In addition, we found that expression of p53 and Bcl-2 was differentially regulated by AHPN/CD437 in different lung cancer cell lines and may play a role in regulating AHPN/CD437-induced apoptotic process. On constitutive expression of the c-JunAla(63,73) protein, a dominant-negative inhibitor of c-Jun, in A549 cells, nur77 expression and apoptosis induction by AHPN/CD437 were impaired, whereas p21(WAF1/CIP1) induction and G0/G1 arrest were not affected. Furthermore, overexpression of antisense nur77 RNA in A549 and H460 lung cancer cell lines largely inhibited AHPN/CD437-induced apoptosis. Thus, expression of c-Jun and nur77 plays a critical role in AHPN/CD437-induced apoptosis. Together, our results reveal a novel pathway for retinoid-induced apoptosis and suggest that AHPN/CD437 or analogs may have a better therapeutic efficacy against lung cancer.

Studies have shown that many synthetic and natural chemicals, classified as endocrine-disrupting chemicals (EDCs), disrupt the normal endocrine system function in both humans and animal species. In our recent study, we used human HepG2 (hepatocellular cancer), HeLa (cervical cancer), and Ishikawa (endometrial cancer) cell lines to analyze the estrogenic effects of a set of known EDCs on the ERs. Our studies demonstrate the mechanistic importance of chemical structure similarities and cell type/promoter specificity when evaluating the potential activities of EDCs. The synthetic EDCs, such as BPA and its analogs, mainly affect ERα and can act as both agonists and antagonists in a dose-dependent manner. The natural EDCs (daidzein and genistein) are stronger estrogens due to their estrogenic activations for both ERα and ERβ. Most importantly, the dosage determines whether a specific endocrine disrupting compound is beneficial or toxic to the human population and one mechanism cannot explain the complexity of ...