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Abstract: In this paper, the controllable band width, resolution and sample loading were investigated by the injection system of free-flow electrophoresis (FFE) with gratis gravity. Two general injection methods were described herein. The first method was the one in which sample injection fluxes were variable with constant background flux, while the second was the one in which the background fluxes were flexible with stable sample flux. With methyl green and crystal violet as two viewable model compounds, a series of experiments were performed, and the experimental results revealed that (1) the sample band width could be under desiring control through the regulation of ratios between sample and background fluxes, (2) the separative resolution could be also adjusted elaborately via the regulation of flux ratios during the separation of methyl green and crystal violet with only one charge disparity, and (3) the sample loading could be conveniently controlled via the flux ratios and an approximate maximum sample loading could be selected under the condition of just completed separation of two adjoining solutes. In addition, it was observed that the flux ratio had soft influence on the separative resolution of two solutes. These results were of significance to the designs on band width, resolution and sample loading in the newly developed FFE device with gratis gravity. [Copyright &y& Elsevier]

Abstract: The synthesis of mercuric mercaptide of penicillenic acid (MMPA) has been the basis for detection of penicillin for nearly 40years (J. Pharm. Pharmacol., 1972, 24, 790; Chinese Pharmacopoeia Ed. II, 1995). Herein, experiments were performed on: (1) synthesis of MMPA used as a novel mercuric hapten, (2) preparation of mercuric antigen of MMPA-BSA, (3) production of antibodies by rabbits immunized with the antigen, and (4) properties of the antibodies studied by ELISA. The results show that: (1) the antigen is safe for immunized animals; (2) high titer antibodies against MMPA are obtained implying good immunogenicity of the antigen; (3) antisera show slightly higher affinity to OVA-GHS-HgCl than OVA-GSH, indicating weak specific affinity of antisera against mercuric ion. Even the weak specific affinity, the hapten and its antigen have potential uses in immunoassays of mercuric ion in environment and food samples, because of easy chemical selective conversion from mercuric ion to MMPA and complete decomposition of un-reacted penicillin in acidic solution. [Copyright &y& Elsevier]

Abstract: The CCAAT/enhancer-binding protein beta (C/EBPβ) is a critical transcription factor that regulates gene expression during numerous biological processes, including differentiation, metabolism, homeostasis, proliferation, tumorigenesis, inflammation, and apoptosis. In this study, interactions between C/EBPβ and either the Abelson murine leukemia viral oncogene homolog 1 (c-Abl) or the Abl-related gene (Arg) were demonstrated in vitro and in vivo with a direct binding assay and by co-immunoprecipitation, respectively. The Y79 amino acid residue of C/EBPβ was phosphorylated by c-Abl or Arg. The phosphorylation of C/EBPβ resulted in an increased C/EBPβ stability and a potentiation of C/EBPβ transcription activation activity in cells. Expression of the C/EBPβ(Y79F) mutant in HEK293, and K562, and in other cell lines, resulted in less of a delay in the cell cycle compared to the wild type C/EBPβ; furthermore, the C/EBPβ (Y79F) mutant induced an increased apoptosis compared to the wild type C/EBPβ. These findings suggest that the c-Abl family non-receptor tyrosine kinases have a role in the regulation of the C/EBPβ transcription factor. [Copyright &y& Elsevier]

Abstract: This paper introduces a mathematic mode of moving chelation boundary (MCB) for computer simulation of a continuous EDTA-based sample sweeping in capillary electrophoresis (CE). Besides the equations of MCB used herein, the mode also includes electro-neutrality equation, constant current density, jump boundary condition of MCB, Kohlrausch’ regulating function expressed in MCB formulation, product of water, ionic apparent mobility, ionic strength and conductivity of electrolyte as well as simple equilibrium reaction, etc. The simulation software is developed based on the mode. With the software the relevant simulation is carried out, and the corresponding experiments on a MCB are performed. The results on the simulation and experiments demonstrate that (1) the software can simulate a dynamic process, characteristic peak shape and relevant electrophoregram of a MCB; (2) the simulator can quantitatively compute velocities of MCB and complex boundary (CB), all of ionic concentrations (especially the concentration of complex) and sweeping efficiency; (3) these simulation results mentioned above are generally in accordance with the experiments. The simulation software holds evident significances for the study on a MCB and conditional optimization in such an EDTA-based sample sweeping of metal ion in CE. [Copyright &y& Elsevier]

Abstract: The reason why a moving reaction boundary (MRB) can stack analyte in highly saline sample in capillary electrophoresis [C.X. Cao, Y.Z. He, M. Li, Y.T. Qian, S.L. Zhou, L. Yang, Q.S. Qu, Anal. Chem. 74 (2002) 4167] is still unclear. To illuminate the mechanism of such stacking, three MRBs formed by formic acid-NaOH buffer and sodium formate as well as 40, 80 and 120mmol/L sodium chloride in matrixes were studied. The computation with MRB theory shows that sodium chloride in matrix has weak effect on the stacking efficiency, whether the concentration of sodium chloride is set at 40, or 80, or 120mmol/L. The conclusion has been highly manifested by numerous experiments. Furthermore, the computer simulation and theoretical analyses depict that this kind of stacking is induced by the mechanism of MRB, rather than that of electrostacking or isotachophoresis (ITP) under the given electrolytic system. Finally, the application of the sample condensation was achieved for the stacking of analyte(s) in highly saline biological sample of skeletonema costarum’ culture with up to 527mmol/L total salt and health human urine with 150–320mmol/L inorganic ions (Cl−, Na+, K+, PO4 3−, etc.). The results herein have a clear significance to the design on stacking of analyte in highly saline biological sample. [Copyright &y& Elsevier]

Abstract: A novel pigment, named gardecin, has been isolated from gardenia fruits, together with another five known crocins. The pigment, which possessed a structure which is unique among crocins, was characterised using spectrometric techniques, particularly 1D and 2D NMR. The NMR assignments were based on data from 1H NMR, 13C NMR, DEPT, 1H–1H COSY, NOESY, HMQC and HMBC measurements. The five known crocins were identified on the basis of MS, UV/visible and 1D NMR data. Chemical stability and antioxidant ability of gardecin in comparison with the other five crocins were studied. The stronger DPPH free radical-scavenging ability of gardecin compared, with the other crocins, was observed. Kinetic studies have shown that all crocins were unstable under various conditions, but surprisingly gardecin was fairly stable. [Copyright &y& Elsevier]

Abstract: A simple but efficient capillary zone electrophoresis (CZE) method was developed for the fast separation and determination of two misused β2-agonists clenbuterol (CLB) and salbutamol (SAL) from complex background extractants existing in swine feed samples. The proper experimental conditions were achieved as 20.0mmol/l pH 10.5 Na2HPO4–NaOH buffer, 20kV applied voltage, fused-silica capillary of 60.5cm×75μm i.d. (50cm to detector). Under the proper conditions, the two abused drugs can be online isolated from the complex extractants and the separation between CLB and SAL is good, all of the target analytes can be detected within 4.5min. The linear response of CLB and SAL concentration ranges from 2.0 to 100.0μg/ml with high correlation coefficient (R 2 =0.9990) and (R 2 =0.9986), respectively. Limit of detection (LOD) and limit of quantification (LOQ) was calculated to be 0.95 and 3.17μg/ml for CLB, 1.07 and 3.57μg/ml for SAL. The precision values (expressed as R.S.D.) of intra- and inter-day were 1.24–2.36% and 0.90–3.85% for CLB, 0.47–1.64% and 0.91–3.46% for SAL. Recoveries spiked at levels 5.0, 25.0, 80.0μg/ml ranged between 93.30% and 104.33% with R.S.D. less than 5%. Finally, the developed method has been applied to the analysis of real swine feed samples and has achieved satisfactory results. [Copyright &y& Elsevier]

Abstract: Natural phenazines in secondary metabolites of bacteria have been receiving increasing attention in recent years due to their potential usage as antibiotics. In the present study, a rapid and reliable capillary zone electrophoresis (CZE) method was developed and validated for monitoring for the first time dynamic phenazine-1-carboxylic acid (PCA) and the 2-hydroxyphenazine (2-OH-PHZ) production of Pseudomonas chlororaphis GP72 during the entire fermentation cycle. The paper begins with the optimization of separate conditions for 2-OH-PHZ and PCA together with phenazine (PHZ), which is used as internal standard. The optimized conditions are: 10mM, pH 7.3 phosphate buffer, a fused-silica capillary with a total length of 49cm×75μmID, 375μmOD with an effective length of 40cm, 25kV, 13mbar 10s pressure sample injection and 25°C air-cooling. The three compounds could be separated within 2min under optimized conditions. The validation of the newly developed study shows the linear response of 2-OH-PHZ and PCA ranging from 10 to 250μgmL−1 with high correlation coefficient (r =0.9997 and 0.9993, n =7), low limits of detection (0.47 and 0.38μgmL−1) and quantification (1.56 and 1.28μgmL−1), respectively. Good precision values for intra- and inter-day detection and acceptable individual recovery ranges for 2-OH-PHZ and PCA are indicated. The newly developed method was also validated through monitoring dynamic PCA and 2-OH-PHZ production of P. chlororaphis GP72 during an 84h growth cycle. [Copyright &y& Elsevier]

Abstract: A quantitative method of capillary electrophoresis with sample stacking induced by moving reaction boundary (MRB) was developed for sensitive determination of oxymatrine (OMT) and matrine (MT) in rat plasma. The experimental conditions were optimized firstly. Below are the optimized experimental conditions: 20mM sodium formate solution (HCOONa, adjusted to pH 10.70 by ammonia) as sample solution, 3min 14mbar sample injection, 40mM formic buffer (HCOOH–HCOONa, pH 2.60) as stacking buffer, 7min 14mbar injection of stacking buffer, 100mM HCOOH–HCOONa (pH 4.80) as separation buffer, 73cm capillary (effective length 64cm), 21kV voltage, 210nm wavelength. Under the optimized conditions, higher than 60-fold sensitivity improvement of the stacking was simply achieved as compared with capillary zone electrophoresis, and the detectable limits obtained for OMT and MT were 0.26 and 0.19μgmL−1, respectively. Then, numerous demonstrations were carefully performed for the methodological validations of OMT and MT in rate plasma, including high specificity of method, good linearity (r =0.9993 for OMT, r =0.9991 for MT), fair wide linear concentration range (1.30–65.00μgmL−1 for OMT, 0.84–42.00μgmL−1 for MT), low limit of detection (1.03μgmL−1 for OMT, 0.38μgmL−1 for MT), less than 5% intra- and inter-day variance value, and higher than 96% recovery of OMT and MT in plasma. The developed method could be used for the trace analyses of OMT and MT in plasma and was finally used for the investigation on pharmacokinetic study of OMT in rat plasma. [Copyright &y& Elsevier]

Abstract: A simple and rapid method using micellar electrokinetic capillary chromatography (MEKC) was developed for the separation and determination of acrylamide in potato chips at low levels for the first time. The experimental conditions for the separation and quantification of acrylamide were optimized at first. The optimized conditions were: 50mmol/L Na2B4O7 and 40mmol/L SDS at pH 10.0, 12kV applied voltage, 76cm total length (67cm effective length) and 75μm i.d. capillary, 198nm wavelength, 15cm high 25s hydrodynamics sample injection, 20°C air-cooling. The linear response of acrylamide concentration ranges from 0.5 to 100μg/mL with high correlation coefficient (r =0.9986, n =9). The LOD and LOQ were estimated to be 0.1 and 0.33μg/mL based on S/N=3 and 10. The precision values (expressed as R.S.D.) of intra- and inter-day were 0.86–4.35% and 2.61–9.65%, respectively. Recoveries spiked at levels 2, 20, 60μg/mL ranged between 90.86% and 99.6% with R.S.D. less than 6.5%. Finally, the developed method has been applied to the analysis of real samples and has achieved satisfactory results. All of these indicated that it was a reliable method for the quantification of acrylamide in potato chips. [Copyright &y& Elsevier]

Abstract: A capillary zone electrophoresis (CZE) method was developed for the quantitative analysis of lovastatin (Lvt) in capsule of Monascus-Chinese medicine. Lvt in the capsule was separated using an electrolyte system consisting of 16% ethanol (v/v) in 60mM Gly-sodium hydroxide buffer, pH 10.5, 16kV applied voltage, 238nm detection wavelength with a capillary of 51cm×75μm i.d (43cm to detector). Under the optimized conditions, the linear response of Lvt concentration ranges from 4.0 to 240μg/mL with high correlation coefficient (r =0.9998, n =9), the limits of detection (LOD) and quantification (LOQ) for Lvt are 0.73 and 2.42μg/mL, the precision values (expressed as R.S.D.) of intra-day and inter-day are 1.40–2.12% and 1.47–3.88%, respectively. The recoveries of the analyte at three concentration levels are 90.28–100.71%. The developed method can be well used for the quantification of Lvt in the drug in commercial formulations. [Copyright &y& Elsevier]

Abstract: An on-line stacking method based on moving reaction boundary (MRB) was developed for the sensitive determination of barbital and phenobarbital in human urine via capillary electrophoresis (CE). The optimized conditions for the method are: 60mmolL−1 pH 11.0 Gly–NaOH as the background electrolyte, 10mmolL−1 pH 5.5 Gly–HCl as sample buffer, secobarbital as the internal standard (IS), 12.5kV, 1.4psi 10s sample injection, 75μm ID 60.2cm total length (50cm effective length) capillary and 214nm detect wavelength. Under the optimized conditions, the method can well stack and separate barbital and phenobarbital in urine samples and result in 20.5-fold and 22.6-fold improvement in concentration sensitivity for barbital and phenobarbital, respectively. Furthermore, the method holds: (1) good linear calibration functions for the two target compounds (correlation coefficients r >0.999), (2) low limits of detection (0.27μgmL−1 for barbital and 0.26μgmL−1 for phenobarbital), (3) low limits of quantification (0.92μgmL−1 for barbital and 0.87μgmL−1 for phenobarbital), (4) good precision (R.S.D. of intra-day and inter-day less than 5.38% for barbital and 1.67% for phenobarbital, respectively) and (5) high recoveries at three concentration levels (90.27–106.36% for barbital and 93.05–113.60% for phenobarbital in urine). The method is simple, sensitive and efficient, and can fit to the need of clinical and forensic toxicology. [Copyright &y& Elsevier]

Summary: Proteasome-mediated proteolysis is a primary protein degradation pathway in cells. The present study demonstrates that c-Abl and Arg (abl-related gene) tyrosine kinases associate with and phosphorylate the proteasome PSMA7 (α4) subunit at Tyr-153. Consequently, proteasome-dependent proteolysis is compromised. Notably, cells expressing a phosphorylation mutant of PSMA7(Y153F) display impaired G1/S transition and S/G2 progression, highlighting the biological significance of tyrosine phosphorylation of a proteasome subunit as an important cellular regulatory control. [Copyright &y& Elsevier]

Bacteriophage MS2 is used in place of pathogenic viruses in a wide variety of studies that range from testing of compounds for disinfecting surfaces to studying environmental transport and fate of pathogenic viruses in groundwater. MS2 is also used as a pathogen simulant in the research, development, and testing (including open air tests) of methods, systems, and devices for the detection of pathogens in both the battlefield and homeland defense settings. PCR is often used as either an integral part of such detection systems or as a reference method to assess the sensitivity and specificity of microbial detection. To facilitate the detection of MS2 by PCR, we describe here a set of real-time fluorogenic reverse transcription-PCR assays. The sensitivity of the assays (performed with primer pairs and corresponding dye-labeled probes) ranged from 0.4 to 40 fg of MS2 genomic RNA (200 to 20,000 genome equivalents). We also demonstrate the usefulness of the primer pairs in assays without dye-labeled probe that included the DNA-binding dye SYBR green. None of the assays gave false-positive results when tested against 400 pg of several non-MS2 nucleic acid targets. [ABSTRACT FROM AUTHOR]

Conventionally, high-pressure water-based fluids have been injected for hydraulic stimulation of unconventional petroleum resources such as tight gas reservoirs. Apart from improving productivity, water-based frac-fluids have caused environmental and technical issues. As a result, much of the interest has shifted towards alternative frac-fluids. In this regard, n-heptane, as an alternative frac-fluid, is proposed. It necessitates the development of a multi-phase and multi-component (MM) numerical simulator for hydraulic fracturing. Therefore fracture, MM fluid flow, and proppant transport models are implemented in a thermo-hydro-mechanical (THM) coupled FLAC3D-TMVOCMP framework. After verification, the model is applied to a real field case study for optimization of wellbore x in a tight gas reservoir using n-heptane as the frac-fluid. Sensitivity analysis is carried out to investigate the effect of important parameters, such as fluid viscosity, injection rate, reservoir permeability etc., on fracture geometry with the proposed fluid. The quicker fracture closure and flowback of n-heptane compared to water-based fluid is advantageous for better proppant placement, especially in the upper half of the fracture and the early start of natural gas production in tight reservoirs. Finally, fracture designs with a minimum dimensionless conductivity of 30 are proposed. [ABSTRACT FROM AUTHOR]

• High temperature reduces the adhesion between asphalt and concrete. • As the new bond is generated, the adhesion of asphaltene-phenol is the strongest. • Aging reduces the adhesion of molecules and has more impact at high temperatures. In this paper, reactive molecular dynamics is used to investigate the adhesion between asphalt molecules and aggregates, and explore the mechanism of action between asphalt and aggregates. Different asphalt molecules, system temperatures and aging of asphalt are considered. Through numerical simulation, it was found that there are physical (van der Waals force) and chemical interactions between the aggregates and the asphaltene molecules containing hydrogen atoms. The new bond is generated through the chemical reaction, which provides strong bonding force to enhance the adhesion of the interface. Other types of molecules and aggregates are only combined through physical attraction, and the bonding force is weak. In addition, the aging of the asphalt causes the loss of hydrogen atoms, so the adhesion between the asphalt and the aggregate is weakened. In summary, numerical simulation results provided a reference for the research and production of asphalt materials with better adhesion properties. [ABSTRACT FROM AUTHOR]

The Western Liaoning area, where a large number of Jurassic-Cretaceous volcanic rocks are exposed, is one of the typical areas for studying the Mesozoic Paleo-Pacific and Mongolia-Okhotsk subduction process, and lithospheric destruction of North China Craton. The identification and investigation of Early Jurassic adakitic volcanic rocks in the Xintaimen area of Western Liaoning is of particular significance for exploring the volcanic magma source and its composition evolution, tracking the crust-mantle interaction, and revealing the craton destruction and the subduction of oceanic plates. Detailed petrography, zircon U–Pb dating, geochemistry, and zircon Hf isotope studies indicate that the Early Jurassic intermediate-acidic volcanic rocks are mainly composed of trachydacites and a few rhyolites with the formation ages of 178.6–181.9 Ma. Geochemical characteristics show that they have a high content of SiO2, MgO, Al2O3, and total-alkali, typical of the high-K calc-alkaline series. They also show enrichment of light rare earth elements (LREEs) and large ion lithophile elements (LILEs), depletion of heavy rare earth elements (HREEs) and high field strength elements (HFSEs), and have a high content of Sr and low content of Y and Yb, suggesting that they were derived from the partial melting of the lower crust. The εHf(t) values of dated zircons and two-stage model ages (TDM2) vary from −11.6 to −7.4 and from 1692 to 1958 Ma, respectively. During the Early Jurassic, the study area was under long-range tectonic effects with the closure of the Mongolia-Okhotsk Ocean and the subduction of the Paleo-Pacific plate, which caused the basaltic magma to invade the lower crust of the North China Craton. The mantle-derived magma was separated and crystallized while heating the Proterozoic lower crust, and part of the thickened crust melted to form these intermediate-acidic adakitic volcanic rocks. [ABSTRACT FROM AUTHOR]

• BupE improved HFD-induced lipid disorders via FGF21 signaling pathway. • Few ingredients or their metabolites from BupE were detected in rodent plasma by UPLC/Q-TOF-MS. • BupE reversed obesity-related alterations in structure and function of gut microbial communities. • Bacteroides acidifaciens and Ruminococcus gnavus mediated hepatic FGF21 expression underlying the anti-obesity effects of BupE on mice. Obesity and its comorbidities are associated with abnormal lipid metabolism and gut microbiota dysbiosis. Bupleuri Radix is a medicinal plant used in traditional Chinese medicine with the prevention and treatment of obesity-related diseases. In this study, we aim to validate the regulation of Bupleuri Radix Extract (BupE) on lipid metabolism in obese mice, and try to find out the potential active components and reveal the underlying mechanisms. Ingredients in BupE, their circulating metabolites in mice and fecal biotransformation products were analyzed by ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS). Western blotting, RT-PCR and ELISA were used for tests of objective genes and proteins. 16 s rRNA sequencing was performed to examine intestinal bacteria composition and microbes' functional changes were predicted with PICRUSt software. An absolute quantification method was set up via the construction of recombinant plasmid for the assays of intestinal flora. Specific microbial strains were cultured in anaerobic conditions and oral administrated to mice for intestinal mono-colonization. BupE attenuated obesity, liver steatosis, and dyslipidemia in HFD-fed mice by up-regulating the expression of FGF21 in liver and white adipose tissue (WAT) as well as the downstream proteins of FGF21 signal pathway including β-klotho, GLUT1 and PGC-1α, etc. UPLC/Q-TOF-MS fingerprints showed no compounds from BupE or their metabolites or biotransformation products were detected in rodent serum samples. High-throughput pyrosequencing data indicated that BupE reversed obesity-induced constructional and functional alterations of intestinal flora. Two bacterial strains, Bacteroides acidifaciens (B. acidifaciens) and Ruminococcus gnavus (R. gnavus), were separated and identified from the feces of obese mice and by intestinal mono-colonization they were verified to intervene in the anti-obesity effects of BupE on mice. These data suggest that BupE protects against diet-induced obesity and counteracts metabolic syndrome features consistent with a mechanism involving the gut-liver axis that boosts hepatic FGF21 secretion and consequent down-stream proteins expression relating to lipid metabolism. And in this gut-liver axis, intestinal microbes such as B.acidifaciens and R.gnavus play an indispensable role. [ABSTRACT FROM AUTHOR]

• Hybrid PEG/GONR/MMT networks are constructed via a bio-inspired strategy. • The hybrid networks produce synergistic reinforcing and toughening efficiencies. • The nacre-like networks show excellent flame resistance and structural stability. • Efficient fire alarm responses (fire rapid detection and early warning) are obtained. Water-based hybrid graphene oxide nanoribbon (GONR)/montmorillonite (MMT)/polyethylene glycol (PEG) networks were prepared by using a facile bio-inspired low-temperature evaporation induced assembling process. Multiple non-covalent and covalent interactions together with a high orientation level of MMT were constructed in the hybrid PEG/MMT/GONR networks. As a result, the hybrid networks exhibit synergistic reinforcing and toughening efficiencies when compared with the composites modified with the single-phase filler, e.g. 152% and 167% increase in tensile strength for the optimized ternary composites in comparison with those of the binary composites. Moreover, the nacre-like hybrid networks show excellent flame resistance and structural stability in a flame due to the formation of interconnected and compact char after combustion, which can be applied as protective coatings to combustible materials. The hybrid coatings not only improve the flame-retardant property (e.g. ~46% decrease in heat release rate at 30 wt%) of the combustible PU foam materials significantly, but also provide ideal fire alarm responses (e.g. rapid flame detection of ~2 s and effective fire early warning signals in pre-combustion). Owing to the green and versatile synthesis scheme, excellent mechanical performance and flame resistance, these hybrid PEG/MMT/GONR networks are promising widespread application. [ABSTRACT FROM AUTHOR]

• The first case of organic small molecule fluorescent probe (Cr6P1) based on ESIPT mechanism for the detection of Cr(VI) has been developed. • Cr6P1 shows excellent ratiometric selectivity and high sensitivity for Cr(VI) (LOD = 13 nM). • The probe is applied in the analysis of actual water samples with satisfactory results. A new ratiometric fluorescent probe for sensitive and selective detection of chromium(VI) under acidic conditions using spirolactamized benzothiazole-substituted N,N-diethylrhodol (Cr6P1) was developed. The probe Cr6P1 showed excellent ratiometric selectivity and high sensitivity for Cr(VI) in acidic solutions, and the detection limit for Cr(VI) was as low as 13 nM (6.9 × 10−4 mg/L). As far as we know, this is the first ratiometric probe based on small organic fluorescence molecules for the detection of Cr(VI). The probe was also applied for detecting Cr(VI) by fluorescent test strips and in the analysis of actual water samples with satisfactory results. [ABSTRACT FROM AUTHOR]

When tunnels are constructed under difficult geotechnical conditions in urban areas, tunnel face stability is one of the main issues to be addressed. To ensure tunnel face stability and reduce the impact of tunneling on adjacent structures, a few alternative procedures of ground reinforcement should be adopted, which includes reinforcing the soil ahead of the face using longitudinal fiberglass dowels alone or together with a steel pipe umbrella. It is of great academic value and engineering signification to reasonably determine the limit reinforcement density of these ground reinforcements. In this paper, an analytical prediction model is proposed by using the limit analysis method to analyze the tunnel face stability, and the favorable effects of longitudinal fiberglass dowels and steel pipe umbrella on tunnel face stability are investigated quantitatively. The analytical prediction model consists of a wedge ahead of the tunnel face, distributed force acting on the wedge exerted by overlying ground, and the support forces stem from the longitudinal fiberglass dowels. Moreover, sensitivity analysis is conducted to study the effect of the depth of cover, the tunnel shape, the reinforcement installation interval and the reduction factor on the required limit reinforcement density. [ABSTRACT FROM AUTHOR]

Laser cladding of (F e 0.497 C r 0.243 M o 0.084 B 0.093 C 0.084) 98 N b 2 on 45 steel substrate was fabricated by using a coaxial powder feeding method with the maximum thickness of 1 mm coating. The effect of the laser scanning speed on macromorphology, microstructure and microhardness of cladding layer and corrosion resistance was investigated. From the substrate to the upper layer, the growth structures of the coating are plane crystal, cellular crystal, columnar crystal, equiaxed crystal and amorphous, respectively. The amorphous content in the coatings is dependent upon laser scanning speed which will influence the dilution rate and actual cooling rate by changing the heat input. As scanning speed increasing, the coating revealed the property of higher hardness and better corrosion resistance, which can be attributed to fine-grain strengthening, dispersion strengthening and growth of the amorphous phase. Moreover, the amorphous phase (HV 1024) showed a much higher value of microhardness than that of the crystalline phase (HV 706), which indicate that the amorphous phase is the main contributor to the average hardness of laser deposited metallic glass. • Fe-based amorphous coating was prepared by laser cladding technology. • The coating layers were characterized using XRD and SEM. • EDS analysis of coating structure and composition. • The proposed coatings showed high hardness and superior corrosion resistance. [ABSTRACT FROM AUTHOR]

Ten-eleven-translocation (Tet) proteins are 5-methylcytosine oxidases and have profound impact on DNA methylation and genes expression. This study aimed to investigate the role of Tet2 and its association with Foxp3 DNA methylation in regulatory T (Treg) cell of allergic rhinitis (AR). CD4+CD25+Treg cells were sorted from peripheral blood lymphocytes drawn from AR patients and spleen lymphocytes drawn from OVA-exposed mice by flow cytometry. Tet2 and Foxp3 expressions were studied in sorted Treg cells. DNA methylation of CpG sites in Foxp3 in Treg cells was analyzed by pyrosequencing. TET2 protein binding to Foxp3 DNA in Treg cells was detected by chromatin immunoprecipitation followed by quantitative PCR (ChIP-qPCR). Treg cells drawn from AR patients and OVA-exposed mice showed reduction in cells counts, expression of Foxp3 mRNA and protein and down-regulation of Tet2, compared with the controls. Hypermethylation of Foxp3 TSDR and decline of TET2 binding to Foxp3 TSDR , but not promoter, were noted in Treg cells of OVA-exposed mice. Significant negative correlations between Tet2 expression and Foxp3 TSDR methylation, Foxp3 TSDR methylation and Foxp3 expression, and positive correlation between Foxp3 expression and Treg cells percentage were demonstrated by correlation analysis. This study demonstrated that down-regulation of Tet2 was associated with higher methylation level of Foxp3 TSDR , reduction in Foxp3 expression and Treg cells percentage in AR, suggesting that Tet2 probably modulated the function of Treg cells in AR through Foxp3 methylation. Unlabelled Image [ABSTRACT FROM AUTHOR]

Background: SARS-Cov is the etiologic agent of severe acute respiratory syndrome. An understanding of the antibody responses to the viral components is very important for diagnosis and vaccine development. Objective: The spectrum of SARS-specific antibody profiles in SARS patients was investigated from 7 to 210 days after the onset of the symptoms. Study design: Serial serum samples from 14 SARS patients were isolated from 7 to 210 days after the onset of the symptoms, and were tested for anti-viral IgG and IgM by indirect immunofluorescence tests (IFA), anti-nucleocaspid antibody by ELISA tests and viral neutralization. Results: Anti-viral (IgG) and anti-nucleocaspid antibodies were observed in 13 of 14 patients at 14 days after the onset of symptoms, and in all 14 patients at 30–210 days thereafter. Anti-viral antibody (IgM) was detected maximally at 30 days, later than that for the IgG class. IgM antibody declined and became undetectable between 60 to 180 days after the onset of the symptoms. Neutralizing viral antibodies were demonstrated in the sera from all of the patients with SARS symptoms. Conclusions: Anti-viral IgG, IgM, and anti-nucleocaspid antibodies were detected 7–30 days in patients after the onset of SARS symptoms. Anti-viral IgM antibodies disappeared earlier than IgG. Viral neutralization was demonstrated in the sera from the convalescent patients. [Copyright &y& Elsevier]

isolation, structure elucidation, plausible biogenetic pathway and biological activities [ABSTRACT FROM AUTHOR]

isolation, structure elucidation, plausible biogenetic pathway and biological activities [ABSTRACT FROM AUTHOR]

The title compounds are obtained with high regio- and stereoselectivity by three-component domino reaction of glutaraldehyde, malononitrile, and β-ketoamides under microwave irradiation. [ABSTRACT FROM AUTHOR]

The outcome of the reaction is strongly temperature-dependent. [ABSTRACT FROM AUTHOR]

Reductive cyclization of nitroaryl substrates using a low valent titanium reagent allows the synthesis of the title compounds (II) and (IV). [ABSTRACT FROM AUTHOR]

Abstract: This paper investigated potential utility of capillary zone electrophoresis (CZE) for very succinct but robust quantitative analysis of pyoluteorin (Plt) in anti-fungal fermentation liquor of Pseudomonas species. The experimental conditions for the separation and quantification of Plt were optimized at first. The optimized conditions are: 80mmol/L pH 8.40 Gly-NaOH buffer, 51cm total length (42cm effective) and 75μm I.D. capillary, 230nm wavelength, 25kV, 13mbar 10s pressure sample injection and 24°C air-cooling. Under the optimized conditions, the migration times of Plt and the internal standard phenobarbital are 2.09 and 2.49min, respectively, the linear response of Plt concentration ranges from 5.0 to 1000μg/mL with high correlation coefficient (r =0.99977, n =9), the limits of detection (LOD) and quantification (LOQ) for Plt are 0.66 and 2.2μg/mL, the precision values (expressed as R.S.D.) of intra- and inter-day are 1.19–1.94% and 1.55–6.21%, respectively, the recoveries of Plt at three concentration levels of 750, 250 and 50μg/mL range from 90.31% to 97.85% and to 98.96%, respectively. The developed method can be well used for the quantification of Plt in the fermentation liquor. [Copyright &y& Elsevier]