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Background The amino acid substitutions caused by ABO gene variants are usually predicted to impact the glycosyltransferase function. Here, the effect of an amino acid substitution in the vicinity of the catalytic active region of the B-glycosyltransferase was explored in vitro and in silico study, which is important for further recognizing the ABO subgroup. Methods The ABO serological tests were performed by the routine methods. The ABO genotype was analyzed by polymerase chain reaction and sequenced bidirectionally. The haplotype of the variant allele was separated using single-strand amplification and sequencing with allele-specific primers. Stably expression cell lines with variant were constructed for study in vitro. 3D structure of the B-glycosyltransferase (GTB) variant was simulated by PyMOL software. The free energy change (ΔΔG) was calculated by FoldX. Results A variant c.737A > G was identified in a Chinese individual with Bweak phenotype, which led to an amino acid substitution p.Y246C in the vicinity of the catalytic active region of GTB enzyme. The stably expression cell lines with variant and wild type were successfully established and showed that the variant caused a decrease in protein levels and/or enzyme activity. The 3D structural of the GTB modelling found the amino acid substitution p.Y246C caused the hydrogen bond of the protein changes. Meanwhile, the free energy change (ΔΔG) value predicted the destabilizing effect on the variant GTB. Discussion The p.Y246C variant in the vicinity of the enzyme active centre reduced the antigen expression because of greatly destabilizing effect on the GTB variant.

To explore the novel properties and applications of two-dimensional black phosphorene, we perform a first-principles study on the modulation of the structure and electronic properties of bilayer phosphorene nanoribbons (BPNRs) by using transition metal (TM = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, and Cu) atoms. For one-dimensional zigzag-edge AA-stacked bilayer phosphorene nanoribbons with hydrogen passivation, we find that the atomic stacking of the BPNRs reorders from the AA to the AE stacking. The AE-stacked structure is the most stable structure for one-dimensional zigzag BPNRs. All the BPNRs with widths N = 4–10 exhibit semiconductor character with indirect band gaps (1.17, 1.01, 0.92, 0.84, 0.75, 0.74, and 0.72 eV), which gradually decrease with increasing nanoribbon width. The adsorption energies show that all the TM atom-adsorbed 4-BPNR compound systems [PTMP] can form stable structures, however, the most stable structures have different adsorption energies (−9.38, −10.73, −13.19, −8.26, −13.68, −9.73, −10.41, −10.33, and −5.98 eV) for different TM (Sc, Ti, V, Cr, Mn, Fe, Co, Ni and Cu) atoms. The calculated bond lengths, charge transfer, and difference charge density of [PMnP] systems indicate that there are strong chemical interactions between the TM atoms and their adjacent P atoms in the BPNRs, resulting in the formation of TM-P ionic bonds. The adsorption of TM atoms induces various electronic structures in 4-BPNR. The [PTMP]1 systems exhibit metallic properties with the adsorption of Sc, Co, and Cu atoms, and semiconductor properties with the adsorption of Ti, V, Cr, Mn, Fe, and Ni atoms with band gaps of 0.30, 0.18, 0.19, 0.20, 0.61, and 0.08 eV, respectively. The Ni and Cu adsorption systems show magnetic quenching with no magnetic moments in all the compound systems [PTMP]. The [PCrP] 1 has the maximum magnetic moment of approximately 3.62 μB amongst all the [PTMP]1 systems, while the [PVP]1 and [PMnP]1 systems have magnetic moments of 1.66 μB and 1.84 μB, respectively. Our results show that TM atom-adsorbed bilayer phosphorene nanoribbons exhibit tunable electronic structures and magnetic properties for potential applications in nanoelectronics.

The characteristics and generation mechanism of (Ti,Nb,V)(C,N) precipitates larger than 2 μm in Nb-containing H13 bar steel were studied. The results show that two types of (Ti,Nb,V)(C,N) phases exist—a Ti-V-rich one and an Nb-rich one—in the form of single or complex precipitates. The sizes of the single Ti-V-rich (Ti,Nb,V)(C,N) precipitates are mostly within 5 to 10 μm, whereas the sizes of the single Nb-rich precipitates are mostly 2–5 μm. The complex precipitates are larger and contain an inner Ti-V-rich layer and an outer Nb-rich layer. The compositional distribution of (Ti,Nb,V)(C,N) is concentrated. The average composition of the single Ti-V-rich phase is (Ti0.511V0.356Nb0.133)(C x N y ), whereas that for the single Nb-rich phase is (Ti0.061V0.263Nb0.676)(C x N y ). The calculation results based on the Scheil–Gulliver model in the Thermo-Calc software combining with the thermal stability experiments show that the large phases precipitate during the solidification process. With the development of solidification, the Ti-V-rich phase precipitates first and becomes homogeneous during the subsequent temperature reduction and heat treatment processes. The Nb-rich phase appears later.

This work presents a method to solve the weak solubility of zinc chloride (ZnCl2) in the ethanol by adding some reasonable water into an ethanol electrolyte containing ZnCl2 and myristic acid (CH3(CH2)12COOH). A rapid one-step electrodeposition process was developed to fabricate anodic (2.5 min) and cathodic (40 s) superhydrophobic surfaces of copper substrate (contact angle more than 150°) in an aqueous ethanol electrolyte. Morphology, composition, chemical structure and superhydrophobicity of these superhydrophobic surfaces were investigated by SEM, FTIR, XRD, and contact angle measurement, respectively. The results indicate that water ratio of the electrolyte can reduce the required deposition time, superhydrophobic surface needs over 30 min with anhydrous electrolyte, while it needs only 2.5 min with electrolyte including 10 mL water, and the maximum contact angle of anodic surface is 166° and that of the cathodic surface is 168°. Two copper electrode surfaces have different reactions in the process of electrodeposition time, and the anodic copper surface covers copper myristate (Cu[CH3(CH2)12COO]2) and cupric chloride (CuCl); while, zinc myristate (Zn[CH3(CH2)12COO]2) and pure zinc (Zn) appear on the cathodic surface.

In the present work, the reoxidation of Al-killed molten steel from the magnesia-chromite refractory was investigated. Firstly, the composition and the phases of magnesia-chromite bricks from three different steelmaking shops were analyzed. Secondly, the magnesia-chromite bricks were immersed in Al-killed molten steel for a determined time to observe the reaction mechanism. Finally, the reoxidation of Al-killed molten steel by the magnesia-chromite bricks was evaluated based on a comparison with the pure magnesia crucibles. The XRF showed the Fe2O3 content of the magnesia-chromite bricks is about 6 mass%, and the Cr2O3 content is in a range of 13–19 mass%. The XRD pattern showed the phases in the bricks are mainly MgO and (Mg,Fe)(Cr,Al,Fe)2O4. The fracture surface of magnesia-chromite bricks after immersion in Al-killed molten steel indicated that there exists a reacted layer, and the reacted layer formed after immersion in the low Cr steel is more obvious than that formed after immersion in the high Cr steel. The SEM–EDS of magnesia-chromite bricks showed that (Mg,Fe)(Cr,Al,Fe)2O4 in the reacted layer decreased after immersion in Al-killed molten steel, especially in the low Cr molten steel. Compared with steel melted in pure magnesia crucibles, the total oxygen of steel melt in magnesia-chromite crucibles showed a lower decreasing rate, and the rate of Cr increase and Al loss were much larger, especially in the low Cr molten steel.

In the present paper, the iron nanowires (containing single Fe atomic chain and Fen nanowire (n=5, 9 and 13)) encapsulated in (8,8) silicon nitride nanotubes (SiNNTs) have been investigated systematically using the first-principles within GGA. For the pristine (8,8) SiNNT, a ferromagnetic ground state is more favorable, and the semiconducting character is observed. After single Fe atom chain encapsulated inside (8,8) SiNNT, two possible configurations are determined depending on the distance from the wire to the tubewall. Furthermore, these two configurations keep high spin-dependent transport and thus can be used in spintronics devices. As for the Fen nanowires encapsulated in (8,8) SiNNTs (Fen@(8,8)), the spin-dependent transport are badly disturbed, but the stabilities of metal wires are reinforced in Fen@(8,8) systems. In particular, an enhanced ferromagnetism is observed after the Fe13 nanowire encapsulated into the (8,8) SiNNT. The results suggest that the Fen@(8,8) systems can be used in the magnetic storage industries.

In the present work, the influence of sulfur addition to the high basicity slag on the Al-killed molten steel with high sulfur content was investigated by using a vacuum induction furnace at 1873 K in MgO crucibles. CaO–SiO2–Al2O3–MgO–CaS slags were used to study the effect of high basicity slags with different CaS contents on sulfur loss, aluminum loss, and total oxygen content in the molten steel. It is shown that the sulfur content in the molten steel decreased with the time, and the addition of CaS into the slag can reduce the sulfur loss in the molten steel. Moreover, there was a decreasing tendency of the aluminum content in the molten steel with the time, and the addition of CaS into the slag can reduce the aluminum loss in the molten steel. Total oxygen content in the molten steel first increased and then decreased with the time when no CaS was added into the slag. However, it decreased monotonically with the time when the addition of CaS was made into the slag.

Application of Lactobacillus plantarum, Staphylococcus aureus, Hansenula yeast, three kinds of fermented sausages as a leavening agent, determines bacteria in fermented sausage fermentation process and the physical and chemical indicators of change. In the fermentation process, the pH value keeps falling, and 18h of fermentation, pH value reaches 5.109. The moisture and nitrite has been in decline. In the early stage of fermentation, Lactobacillus breeds slowly, yeast and cocci grow rapidly. After 6 h of fermentation, the lactic acid bacteria blooms, staphylococci and yeast growth and reproduction is inhibited, the number declines, when the fermentation time reaches15h, the number of staphylococci and yeasts begin to increase.

In the present work, reoxidation of Al-killed steel by Ca(OH)2 in high basicity slag was investigated by using laboratory experiments at 1873 K in MgO crucibles with various amount of Ca(OH)2 addition into slag. The CaO–SiO2–Al2O3–MgO–Ca(OH)2 slags were used to study the effect of Ca(OH)2 on total oxygen content, aluminum loss, and FeO content in the slag. It was shown that total oxygen content decreased with the time when no Ca(OH)2 was added into the slag, but it first increased and then decreased with the time when the addition of Ca(OH)2 was made. Moreover, aluminum loss and FeO content in the slag increased with increasing Ca(OH)2 content.

The substitution of a single boron atom or two atoms boron and nitrogen in (4,4) and (8,0) boron nitride nanotubes (BNNTs) by 3d transition metal (TM = V, Cr or Mn) atom has been systemically studied using first-principle calculations. All optimized TM-doped BNNT systems have obvious local deformation of the nanotubes, and almost all TM atoms protrude to the exterior of the wall. The substitution of TM atoms induces some impurity states within the band gaps of the pure BNNTs. The B site V-doped (4,4) BNNT system is half-metal while the BN1 site TM-doped (4,4) BNNT systems are metallicity. All the TM-doped (8,0) BNNT systems are still semiconductor. Overall charges are transferred from the TM atoms to more electronegative BNNTs. The substituted doping of TM atoms gives rise to magnetic moments which mainly stem from TM atoms. Therefore, the substitution of doping by TM enhances the chemical reactivity and significantly increases the conductivity of pure BNNT, and renders the TM-doped BNNT systems have larger magnetic moments. All these show the TM-doped BNNT systems have potential applications in hydrogen storage, gas sensing, catalysts, spintronics and magnetic data storage devices.

The structural, electronic and magnetic properties of transition metal TM n (TM=Fe, Co or Ni and n =5, 9 or 13) nanowires encapsulated inside (8,8) zinc oxide nanotube (ZnONT) have been investigated by first-principles calculations. Due to strong interaction between inner TM 13 nanowires and outer ZnONT, not only a near square cross section shape is formed for outer ZnONT but also an anticlockwise rotation about their common axis takes place for the TM 13 nanowires. The combining processes of all TM n @(8,8) composites are exothermic showing that the semiconducting (8,8) ZnONT can therefore be used to shield these TM nanowires. For TM 13 @(8,8) composites, the charge density accumulated strongly around the O atoms implies a large charge transfer from TM atoms (as well as from Zn atom) to more electronegative O atoms and thus the ionic binding characters between them. The magnetic moment of TM n @(8,8) composites decreases with the increasing TM n nanowire thickness, and there is almost no reduction in the magnetic moments of TM 5 @(8,8) and TM 9 @(8,8) composites with respect to the corresponding freestanding TM 5 and TM 9 nanowires, reflecting that the TM n @(8,8) composites especially the loosely wrapped TM 5 @(8,8) and TM 9 @(8,8) composites can be utilized in high density magnetic recording devices.

The modified analytical embedded atom method (MAEAM) is applied to calculate the phonon dispersion of three noble metals Cu, Ag and Au in four symmetry and four off-symmetry directions. The calculated dispersion curves are in good agreement with the available experimental results, which implies that the predicted phonon dispersion curves along off-symmetry directions are well behaved. It has been further proved that the MAEAM gives a good description of many-body interatomic interactions in noble metals Cu, Ag and Au. For three noble metals, the phonon frequency decreases for Cu, Ag and Au successively due to the ratio of cohesion energy to atom mass decreases.

Xiaojiang watershed is a typical karst agricultural region of Yunan Province, China. A case study of land-use changes documents changes of soil properties from 1982 to 2003. The results are as follows: (1) The total land use transformed covers 610.12 km2, of which land use changed from unused land into cultivated land and forestland, and forestland into cultivated land during the past 20 years in Xiaojiang watershed. (2) The rapid growth of population and economic development were the main driving forces of cultivated land increase. (3) Soil properties showed modification owing to different land-use changes. The contents of the soil organic matter, total nitrogen, and total phosphorus in 2003 were significantly lower than that in 1982 after the forestland and unused land were transformed into the cultivated land, but the soil pH increased significantly in 2003. Organic matter, total nitrogen, and total phosphorus for shorter-time reforestation land declined, but the pH increased. Soil properties have improved significantly after cropland was transformed into orchard land. The organic matter, total nitrogen, total phosphorus, available nitrogen, and available phosphorus declined significantly, but pH increased significantly after rock desertification.

Objective: This study aimed to establish chemiluminescent immunoassay (CLIA) for quantitative determination of theophylline levels in human serum. Methods: To measure the concentration of theophylline (n=122) and evaluate the assay. Results: The linear range of the CLIA method was 0.51:_40 mg/L (Y=1.02X+0.44, r=0.995). The intra and inter CV (coefficient variance) of CLIA were 3.20% and 3.57%, respectively. The average recovery rate was 102.3%. This method was free from interference by brilirubin (

The research on infrared radiant characteristics of typical target is important for the detection and recognition of target, infrared simulation calculation and design of electro-optical countermeasures. Thus it is essential to select appropriate test method and optimal calculation method to improve the test accuracy and reliability of infrared radiant intensity. In this paper, three instruments including SR5000 spectroradiometer (CI, MigdalHaEmek, Israel), remote sensing interferometer spectrometer Tensor37 (Bruker, Germany) and Image IR8325 (InfraTec Ltd, Germany) mid-infrared thermal imager were applied to test the infrared radiant (1μm-3μm，3μm-5μm) intensity of decoy samples. Three methods were designed based on two operational principles including direct test and indirect test. The SR5000 spectroradiometer which is able to obtain the value of radian intensity immediately is regard as direct test. The other two instruments which deduce and calculate infrared radiant intensity according to Planck's law and Lambert's cosine law with some preliminary tested parameters such as the response voltage，the distribution of infrared radiant temperature of flaming samples and calibrated data by blackbody, however, are regard as indirect test. Reasons for the diversity of experiment results were provided through analysis on the concrete measurement theory and detailed calculation methods. Moreover, some rules and suggestions were put forward to improve the test accuracy and reliability of infrared radiant intensity when different methods were adopted. It is shown from experiment results that the average mid-infrared radiant intensity obtained from SR5000 was about 903W/Sr in near-infrared band，whereas Tensor 37 and Image IR8325 was about 834W/Sr and 547 W/Sr respectively. It was proved that maximum relative of calculated results from remote sensing interferometer spectrometer Tensor37 and results measured with SR5000 spectroradiometer is below 13%, which meet the general accuracy requirements. Although rigorous reasoning applied, results gained by Image IR8325 mid-infrared thermal imager varied so much from above-mentioned two instruments and the relative error is about 25%~40%. It is analyzed that complexity of the measurement procedure and similarity hypothesis is the main reason for the errors generated.

It has been shown that cadmium and fluoride may both have adverse effects on liver and kidney functions, but most studies focus on a single agent. In this study, we observed the effects of cadmium and fluoride on liver and kidney functions using a rat model. Total of 24 Sprague–Dawley male rats were divided into four groups, one control group and three exposure groups that were given cadmium (50 mg/L) and fluoride (100 mg/L) alone or in combination via drinking water. At the 12th week, urine, blood, and kidney tissues were collected. Aspartate transaminase, alanine transaminase (ALT), urinary β2-microglobulin, and albumin were determined. Contents of malondialdehyde (MDA) and superoxide dismutase (SOD) in liver and kidney homogenates were measured to evaluate oxidative stress. There was a significant increase in serum ALT and urinary β2-microglobulin of rats in exposure groups compared with control. Serum ALT and urinary β2-microglobulin of rats exposed to cadmium and fluoride in combination was significantly higher than those treated with cadmium alone and fluoride alone. SOD declined significantly and MDA increased in combination group compared with control and those treated with cadmium and fluoride alone. Cadmium and fluoride co-exposure increase the liver and kidney damage compared with that exposed to cadmium or fluoride alone.

The characteristics and generating mechanism of heterogeneous carbonitride with micron size in H13 + Nb bar are studied. Three types of precipitates are observed according to the number of layers, that is, two-layer ones, three-layer ones, and four-layer ones. Two-layer precipitate contains the oxide core and the outer Ti–V-rich carbonitride, while three-layer precipitate has one more Nb-rich carbonitride at the outside. Four-layer precipitate has a V-rich carbonitride at the outmost layer besides the inner three types of phases similar to that in the three-layer precipitate. The size of these large precipitates can be even up to tens of microns. The oxide cores are mainly stoichiometric spinel MgAl2O4 and generated in the liquid steel before solidification. The compositional characteristics and precipitating sequence of carbonitride can be well explained through calculation by Scheil–Gulliver model in Thermo-Calc. Ti–V-rich phase precipitates first during solidification, after which Nb-rich phase and V-rich phase precipitates successively. Some dissolution occurs between the different layers during the following temperature reducing and heating treatment process.

One novel dysprosium coordination polymer [Dy(PIC)3(H2O)2]n (HPIC = pyridine-4-carboxylic acid) has been synthesized. X-ray analysis reveals that it forms the chain-like molecular structure through the bridged oxygen atoms of the carbonyl groups. The title coordination polymer crystallizes in the monoclinic system, space group C2/c, with lattice parameters: a=20.243(9) A, b=11.576(5) A, c=9.834(4) A, β=110.601(2)°, V=2078(2) A3, Dc=1.805 mg/m3, Z=4, F(000)=1100, GOF = 1.11, R1=0.0404. The photophysical property has been studied with ultraviolet absorption spectrum, excitation and emission spectrum. The luminescence spectra show the stronger blue emission than yellow emission.

Pancreatic cancer is a devastating disease characterized by low sensitivity to conventional chemotherapeutic treatment that has a poor prognosis. Therefore, novel effective chemotherapeutic regimens need to be developed. In this study, we analyzed the combined cytotoxic effect of triptolide and hydroxycamptothecin (HCPT) on pancreatic cancer cell line PANC-1 by using 3-(4.5-dimethylthiazol-2-yl)-5-(3-carboxy-methoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) and fluorescence- activated cell sorting (FACS) assays. Our results showed that the sensitivity of a combined therapy using triptolide and HCPT was higher than that of triptolide or HCPT alone and that activation of caspase-9/caspase-3 and inhibition of nuclear factor-kappaB (NF-κB) signaling pathway may contribute to the synergistic cytotoxic effect of this combination therapy. Therefore, our observations provided evidence supporting the clinical applications of the combination chemotherapy using triptolide and HCPT for treating pancreatic cancer.

The characteristics of the large heterogeneous precipitates (Ti,Nb,V)(C,N) with oxide nucleus in H13+Nb tool steel produced through ESR process were studied, and compared with the ones produced without the remelting process. ESR process with slag 50wt% CaF2 -35wt% Al2 O3 -10wt% CaO-5%wt% MgO has a negative effect on controlling the primary carbonitride for the larger amount of ones with size >5 μ m, which is partly due to the different heterogeneous nucleation characteristics. 100% of the nucleant oxide in the NON-ESR samples is Al2 O3 -MgO spinel with stoichiometric composition and the size is mostly located in 0.5 ~ 1.5μ m, which shows a strong selectivity on the nucleant inclusions. However, the trend is not obvious for the ESR samples in which the average value of Mg/Al atomic ratio in nucleant spinel is just 0.135. The behavior of heterogeneous nucleation on spinel with low Mg/Al ratio in ESR sample is closer to that on alumina, which leads to the degeneration of the heterogeneous nucleation. It is a part of reason for the increment of the precipitates size. The thermodynamic analyses show that it should keep the total content of Mg in liquid steel larger than 4 ppm if the oxide is located in the stoichiometric spinel phase region.

Electron impact excitation cross sections from the ground state and the lowest metastable state 5p56s J = 2 to the excited states of the 5p57p configuration of xenon are calculated systematically using the fully relativistic distorted wave method. Special attention is paid to the configuration interaction effects in the wave-function expansion of target states. The results are in good agreement with the recent experimental data by Jung et al. [Phys. Rev. A 80 (2009) 062708] over the measured energy range. These accurate theoretical results can be used in the modeling and diagnosis of plasmas containing xenon.

The electron impact excitation cross sections from the lowest metastable state 5p56sJ = 2 to the six lowest excited states of the 5p56p configuration of xenon are calculated systematically by using the fully relativistic distorted wave method. In order to discuss the effects of target state descriptions on the electron impact excitation cross sections, two correlation models are used to describe the target states based on the multiconfiguration Dirac–Fock (MCDF) method. It is found that the correlation effects play a very important role in low energy impact. For high energy impact, however, the cross sections are not sensitive to the description of the target states, but many more partial waves must be included.

The molecular distributions and constitutions of several A-240 petroleum and coal tar pitch fractions were investigated using field desorption mass spectrometry. The molecular profiles of all samples analysed were greatly extended and the maximum mass weight of CTP-BSHI approached 640 corresponding to 13 aromatic fused-rings, while that of A-240-BS approximated to 784 matched to 14 kata-condensed rings. The coal tar pitch samples were mainly composed of peri-condensed polyaromatics, with kata-condensed PAHs amounting to 1 4 of total sample. In contrast, A-240 petroleum pitch samples consisted almost totally of polyacenes (or their isomers) and polyaryl alkanes. The extremely different characteristics in the compoundtype distributions between these two pitches reflect the different features of high temperature gas-phase pyrolysis and medium temperature liquid-phase pyrolysis reactions.

Tandem mass spectrometry was used to follow the low temperature catalytic modification of the diesel oil heavy fraction in the presence of aluminium chloride. The molecular distribution from chemical ionization mass spectroscopy (c.i.m.s.) of raw feedstock ranges from 150 to 250, with an average molecular weight of 219 (v.p.o.). That of the finally modified pitch ranges from 200 to 800, mainly concentrated between 200 and 500 with v.p.o. molecular weight of 452. The m.s.-m.s. fragmentation analysis of three dominant, characteristic protonated parent ions m z 207, 373, 385, showed ethyl phenanthrenes (-anthracenes), dimers from phenanthrene (anthracene) and C 1 -phenanthrene with substantial naphthenic groups, dimers from C 1 -phenanthrenes and copolymers from hexahydropyrene with phenanthrene, chrysene with C 2 -naphthalene, etc., respectively, to be the main structural types of these parent mass numbers. This modified pitch material, with a characteristic low degree of condensation and extensive naphthenic structures proved to be suitable for transformation into mesophase pitch with high fluidity and a large domain-type anisotropic texture.