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A new method for real-time detection of carcinoembryonic antigen (CEA) in human serum with high sensitivity and selectivity using surface plasmon resonance (SPR) biosensor was developed. Two kinds of antibodies were used to recognize CEA at different epitopes with high affinity and specificity. Gold nanoparticles (GNPs) modified with streptavidin (SA) were used to further enhance signal specifically via biotin-streptavidin interaction. The binding capacity of the streptavidin-modified gold nanoparticles (SA-GNPs) for ligand biotin was quantified by titration with biotin (5-fluorescein) conjugate to be 10.54 biotin binding sites per 100 nm(2). The developed GNPs enhanced sandwich SPR biosensor successfully fulfilled the sensitive detection of CEA in the range of 1-60 ng/mL with a detection limit of 1.0 ng/mL. Compared to the direct assay format, sandwich format without GNPs and SA-GNPs enhanced sandwich format led to 4.2-fold and 13.8-fold in the sensitivity, respectively. This sensor also showed good selectivity for CEA in the interference study. The results demonstrated that the proposed method could provide a high sensitivity and selectivity in the detection of CEA and offer a promising alternative for cancer biomarker than traditional clinical examinations.

A previous continuum model proposed and recently modified by the authors for describing the heat, mass and momentum transport phenomena in dendrite solidification process of alloy castings was further extended to the solidification cases in an arbitrary electromagnetic (EM)-fields. The extended continuum model and a FEM/FDM joint solution technique were successfully applied to the numerical simulations of directional solidification transport processes in blade-like castings of Pseudo-binary In718 base-4.85 wt.%Nb and Al–4.5 wt.%Cu alloys under a static or harmonic EM-field of different strengths/frequencies. The computational results demonstrate the availability of the present continuum modeling to treat an EM-STP problem, and also reveal that the volume-contraction-driven liquid feeding flow is much more difficult to be suppressed than the buoyancy-induced by means of applying a static magnetic field.

A Direct-SIMPLE scheme is further extended for numerical simulations of heat and species mass transfer, and liquid flow behaviours in solidification processes of shaped alloy castings under various electromagnetic (EM) fields, based on a binary continuum model (a solidification transport phenomena/processes (STP)-based dendrite solidification model). Unlike in a SIMPLE scheme, no iterative computations are needed to achieve the final pressure and velocity corrections in the extended Direct-SIMPLE procedure, therefore extremely high computational efforts can be avoided. Using three different types of model alloys, pseudo-binary In718 base-4.85 wt% Nb, γ(TiAl)-55 at% Al and Al-4.5 wt% Cu systems, sample computations for solving strongly coupled solidification transport phenomena in directionally solidifying shaped castings under static and harmonic EM-fields of different strengths are carried out, to demonstrate the feasibility and efficient calculation performance of the present model and numerical methods. Copyright © 2004 John Wiley & Sons, Ltd.

Numerical techniques for FEM/FDM joint simulation of solidification heat, mass and momentum transport phenomena in directional solidification processes of shaped alloy castings under electromagnetic (EM) fields are developed. In the present joint computer modeling for the EM-fields coupled solidification transport processes, the relevant EM-fields are calculated using a FEM-scheme-based computer code, while the changing fields of temperature, solid-fraction, concentrations, pressure and flow velocity of liquid phase are simulated by the FDM-based numerical methods extended from a previous numerical solidification model of the authors. Specific data-processing techniques are proposed for the conversion of FEM-based EM-fields results to those in the FDM format. The sample computations for EM-fields influenced solidification transport processes of directionally solidified γ(TiAl)-Al% castings are performed to demonstrate the feasibility and effectiveness of the proposed solidification model and numerical methods.

A simple, sensitive and selective turn-on fluorescent aptasensor for adenosine detection was developed based on target-induced split aptamer fragment conjunction and different interactions of graphene oxide and the two states of the designed aptamer sequences.

Polarization measurement approaches only using polarizer and grating is present. The combination polarizers consists of two polarizers: one is γ degree with the X axis; the other is along the Y axis. Binary grating is covered by the combination polarizers, and based on Fraunhofer diffraction, the diffraction intensity formula is deduced. The polarization state of incident light can be gotten by fitting the diffraction pattern with the deduced formula. Compared with the traditional polarization measurement method, this measurement only uses polarizer and grating, therefore, it can be applied to measure a wide wavelength range without replacing device in theory.

Background Many biotechnological and industrial applications can benefit from cold-adapted EglCs through increased efficiency of catalytic processes at low temperature. In our previous study, Citrobacter farmeri A1 which was isolated from a wood-inhabiting termite Reticulitermes labralis could secrete a cold-adapted EglC. However, its EglC was difficult to purify for enzymatic properties detection because of its low activity (0.8 U/ml). The objective of the present study was to clone and express the C. farmeri EglC gene in Escherichia coli to improve production level and determine the enzymatic properties of the recombinant enzyme. Methods The EglC gene was cloned from C. farmeri A1 by thermal asymmetric interlaced PCR. EglC was transformed into vector pET22b and functionally expressed in E. coli. The recombination protein EglC22b was purified for properties detection. Results SDS-PAGE revealed that the molecular mass of the recombinant endoglucanase was approximately 42 kDa. The activity of the E. coli pET22b-EglC crude extract was 9.5 U/ml. Additionally, it was active at pH 6.5–8.0 with an optimum pH of 7.0. The recombinant enzyme had an optimal temperature of 30–40 °C and exhibited >50% relative activity even at 5 °C, whereas it lost approximately 90% of its activity after incubation at 60 °C for 30 min. Its activity was enhanced by Co2+ and Fe3+, but inhibited by Cd2+, Zn2+, Li+, Triton X-100, DMSO, acetonitrile, Tween 80, SDS, and EDTA. Conclusion These biochemical properties indicate that the recombinant enzyme is a cold-adapted endoglucanase that can be used for various industrial applications.

Infrared-to-visible upconversion emission spectrum is investigated in Li + , Ho 3+ and Yb 3+ codoped Y 2 O 3 nanocrystals. By adding Li + ion to the Y 2 O 3 :Ho 3+ /Yb 3+ nanocrystal, the upconversion emission intensity is found being significantly enhanced comparing with that without Li + ion. The two reasons for this enhancement are discussed: one is because of the modification of the local symmetry of the Ho 3+ ion, and the other is because of the reducing number of OH groups. This indicates Li + ion would be a wonderful photoluminescence intensifier for rare-earth.

Visible upconversion emission intensities are investigated in Er3+-doped Y2O3 nanocrystals. We also find that the upconversion intensity varies nonlinearly with the excitation power with a threshold of 110 mW, which indicates that the green and red emissions would be photon avalanche upconversion when the excitation power exceeds the threshold.

Infrared-to-visible upconversion luminescence spectra are investigated in Li + and Er 3+ codoped Y 2 O 3 nanocrystals. By introducing Li + ions, the upconverted emission intensity is found to be greatly enhanced when compared with the nanocrystals with the Li + absent. The cause of the enhancement is believed to be the modification of the local symmetry of the Er 3+ ion, which increases the intra-4f transitions of Er 3+ ion, and the homogeneous distribution of Er 3+ . While in some other Er 3+ doped oxides, such as ZnO, ZrO 2 , etc., the upconversion intensity of Er 3+ ions could also be greatly increased by doping Li + .

A rapid and efficient capillary zone electrophoresis (CZE) method with ultraviolet detection has been successfully developed for the determination of puerarin in Xinkeshu capsules and biological samples. The optimal CZE conditions were determined to be 70 mM H3BO3–Na2B4O7, pH 9.2, injection time 5 s, applied voltage 25 kV, working temperature 25 °C and detection wavelength 254 nm. Under these conditions, a linear range from 17.3 to 138 μg/mL with the correlation coefficient of 0.9998 and limit of detection of 34.6 ng/mL (S/N = 3) for puerarin were obtained. The relative standard deviation of the migration time and peak area of puerarin were 0.23–0.91, 0.43–1.62, 0.10–0.64 and 0.64–1.32% for intra-day and inter-day analyses, respectively. Satisfactory results were obtained for recovery and repeatability. The proposed method was successfully applied to analyze the puerarin content in Xinkeshu capsules and some biological samples with good results. It is suitable for applications in pharmaceutical industries for quality control and in clinical laboratories for therapeutic drug monitoring purposes.

Objectives: In order to improve the expression ability of the non-mitogenic recombinant human acidic fibroblast growth factor(nrhaFGF), the plasmid stability of rhaFGF mutant gene bearing system Escherichia coli BL21(DE3) was investigated widely. Methods: through the screen of strain and medium, the synthetic YH medium was selected as the fermentation medium the plasmid segrative and structural stability and so on were all measured, then produced the nrhaFGF by the addition of ampcillin (Amp) upon induction before the centrifugation of the broth; at last changed the expression strength of beta-lactamases according to the code-bias and site-directed PCR technology. Results: the synthetic medium YH was selected as the fermentation broth for the E.coli expression system; it was found that the plasmid segrative stability was above 90% after 50 generation with no selective pressure,the expression level kept within 25% - 28%,and the 100% stability of PstI digestion graph showed a satisfied structural stability of the system. LB agar plates experiment revealed part of the reason why system lost expression ability during induction; the expression level was improved 13.68% through the centrifugation upon induction, and improved 25% under the condition of IPTG 0.3 mmol/L, Amp 50 mug/mL. Conclusion: the process established in this paper was simple and easy to scale up, and showed a distinct economic benefits.

The calcineurin B-like proteins (CBLs) represent a unique family of calcium sensors in plants. Although extensive studies and remarkable progress have been made in Arabidopsis (Arabidopsis thaliana) CBLs, their functions in other plant species are still quite limited. Here, we report the cloning and functional characterization of ZmCBL4, a novel CBL gene from maize (Zea mays). ZmCBL4 encodes a putative homolog of the Arabidopsis CBL4/SOS3 protein, with novel properties. ZmCBL4 has one copy in maize genome and harbors seven introns in its coding region. ZmCBL4 expressed differentially in various organs of the maize plants at a low level under normal condition, and its expression was regulated by NaCl, LiCl, ABA and PEG treatments. Expression of 35S::ZmCBL4 not only complemented the salt hypersensitivity in Arabidopsis sos3 mutant, but also enhanced the salt tolerance in Arabidopsis wild type at the germination and seedling stages. Moreover, the LiCl tolerance in all of the ZmCBL4-expressing lines increased more significantly as compared with the NaCl tolerance, and in consistent with this, it was found that the expression of Arabidopsis AtNHX8, a putative plasma membrane Li+/H+ antiporter gene identified recently, was induced in these transgenic lines under LiCl stress. The ZmCBL4-expressing Arabidopsis lines accumulated less Na+ and Li+ as compared with the control plants. This study has identified a putative maize CBL gene which functions in the salt stress-elicited calcium signaling and thus in the tolerance to salinity.

Low threshold power density cw laser-induced heat has been observed in [Formula: see text] and [Formula: see text] codoped [Formula: see text] nanocrystals under excitation by a 980 nm IR laser. Codoped [Formula: see text] remarkably reduces the power density threshold of laser-induced heat compared with [Formula: see text] doped [Formula: see text] nanocrystals. When the excitation power density exceed [Formula: see text], [Formula: see text] codoped [Formula: see text] nanocrystals emit strong blackbody radiation. The thermal emission of [Formula: see text] should originate from the multiphonon relaxation between neighboring energy levels. One additional UC-PL enhancement is observed. The UC-PL intensity can be enhanced by an order of magnitude through high temperature calcination caused by light into heat.

Strongly coupled heat, species mass and momentum transport behaviors in melting processes of a 2D blade like casting of Al-4.5Cu%wt and pseudo-binary gamma(TiAl)-55Al%wt alloys were numerically simulated using a continuum model. The strongly pressure-linked liquid flow problems are successfully solved using the authors' proposed direct-SIMPLE algorithm. Simulation results demonstrate the availability and computational efficiency for computer modeling of the transport phenomena in alloy melting processes

Mutational activation of the ras proto-oncogenes is frequently found in skin cancers. However, the nature of downstream signaling pathways from Ras involved in skin carcinogenesis remains poorly understood. Recently, we and others identified phospholipase C (PLC) epsilon as an effector of Ras. Here we have examined the role of PLCepsilon in de novo skin chemical carcinogenesis by using mice whose PLCepsilon is genetically inactivated. PLCepsilon(-/-) mice exhibit delayed onset and markedly reduced incidence of skin squamous tumors induced by initiation with 7,12-dimethylbenz(a)anthracene followed by promotion with 12-O-tetradecanoylphorbol-13-acetate (TPA). Furthermore, the papillomas formed in PLCepsilon(-/-) mice fail to undergo malignant progression into carcinomas, in contrast to a malignant conversion rate of approximately 20% observed with papillomas in PLCepsilon(+/+) mice. In all of the tumors analyzed, the Ha-ras gene is mutationally activated irrespective of the PLCepsilon background. The skin of PLCepsilon(-/-) mice fails to exhibit basal layer cell proliferation and epidermal hyperplasia in response to TPA treatment. These results indicate a crucial role of PLCepsilon in ras oncogene-induced de novo carcinogenesis and downstream signaling from TPA, introducing PLCepsilon as a candidate molecular target for the development of anticancer drugs.

This paper is focused on the MIL STD 1553B protocol and its hardware implementation. MIL STD 1553B is fully called Aircraft internal time Division command/response multiplex data bus. It is used in high noise environments because of its data integrity, it is also widely used in many nonavionic systems. The Chinese military had designated GJB287 X7 standard which is compatible with MIL STD 1553B. A full function of this protocol has been described using Verilog HDL and implemented by XC4000 FPGA chips.

Judd–Ofelt (JO) analysis of Er3+ ions spectral properties in Er3+ doped and Er3+/Li+ codoped Sb2O3–Na2O–SiO2 glasses are performed based on the optical absorption spectra at room temperature. Three phenomenological parameters Ω2, Ω4, and Ω6 are determined. The effects of Li+ on the JO parameters are discussed in terms of the variations in Er3+ bonding nature and ligand fields around Er3+ sites.

The spatiotemporal dynamics of the hydrogen peroxide-thiosulfate-sulfite-perchlorate acid system was investigated in reaction-diffusion medium. In the Petri dish, pulse waves were discovered, which had the maximum life-time and the maximum traveling distance when the initial concentration of thiosulfate was increased. In addition, pulse waves contracted back before disappearing, and the pulse waves with red spot were observed when the initial concentration of hydrogen peroxide was higher. The experimental results were analyzed and explained according to the reaction mechanism of positive and negative feedback in this system.