Carbohydrate-Based Amphiphiles: Resource for Bio-based Surfactants

International audienc

Coupled Three Dimensional Neutronics/Thermal-hydraulics Code STTA for SCWR Core Transient Analysis

ABSTRACT A coupled three dimensional neutronics/thermal-hydraulics code STTA (SCWR Three dimensional Transient Analysis code) is developed for SCWR core transient analysis. Nodal Green's Function Method based on the second boundary condition (NGFMN_K) is used for solving transient neutron diffusion equation. The SCWR sub-channel code ATHAS is integrated into NGFMN_K through the serial integration coupling approach. The NEACRP-L-335 PWR benchmark problem and SCWR rod ejection problems are studied to verify STTA. Numerical results show that the PWR solution of STTA agrees well with reference solutions and the SCWR solution is reasonable. The coupled code can be well applied to the core transients and accidents analysis with 3-D core model during both subcritical pressure and supercritical pressure operation

The Development and Application of Crop Evaluation System Based on GRA

Ever since it was proposed, grey system theory has attracted the attention of scientific researchers and scholars. And it also has been widely used in many fields and solved a large number of practical problems in production, life, and scientific research. With the development and popularization of computer science and network technology, this traditional mathematical model can be applied more simply and efficiently to solve practical problems. Firstly, this paper, to implement steps of grey relational analysis, has made the exclusive analysis and has made the simple introduction to grey relational analysis characteristics. Then, based on grey relational theory and ASP.NET technology, the crop evaluation system is developed. Lastly, by using Excel and the crop evaluation system, the paper carries out a comprehensive evaluation about eight features of Fuji apple, which is from nine different producing areas, respectively. The experiment results show that the crop evaluation system is effective and could greatly improve the work efficiency of the researcher and expand the application scope

Information theory-based algorithm for in silico prediction of PCR products with whole genomic sequences as templates

BACKGROUND: A new algorithm for assessing similarity between primer and template has been developed based on the hypothesis that annealing of primer to template is an information transfer process. RESULTS: Primer sequence is converted to a vector of the full potential hydrogen numbers (3 for G or C, 2 for A or T), while template sequence is converted to a vector of the actual hydrogen bond numbers formed after primer annealing. The former is considered as source information and the latter destination information. An information coefficient is calculated as a measure for fidelity of this information transfer process and thus a measure of similarity between primer and potential annealing site on template. CONCLUSION: Successful prediction of PCR products from whole genomic sequences with a computer program based on the algorithm demonstrated the potential of this new algorithm in areas like in silico PCR and gene finding

Effects of Voltage-Gated K +

Objective. To study the effects and underlying mechanisms of voltage-gated K+ channels on the proliferation of multiple myeloma cells. Methods. RPMI-8226 MM cell line was used for the experiments. Voltage-gated K+ currents and the resting potential were recorded by whole-cell patch-clamp technique. RT-PCR detected Kv channel mRNA expression. Cell viability was analyzed with MTT assay. Cell counting system was employed to monitor cell proliferation. DNA contents and cell volume were analyzed by flow cytometry. Results. Currents recorded in RPMI-8226 cells were confirmed to be voltage-gated K+ channels. A high level of Kv1.3 mRNA was detected but no Kv3.1 mRNA was detected in RPMI-8226 cells. Voltage-gated K+ channel blocker 4-aminopyridine (4-AP) (2 mM) depolarized the resting potential from −42 ± 1.7 mV to −31.8 ± 2.8 mV (P<0.01). The results of MTT assay showed that there was no significant cytotoxicity to RPMI-8226 cells when the 4-AP concentration was lower than 4 mM. 4-AP arrested cell cycle in G0/G1 phase. Cells were synchronized at the G1/S boundary by treatment of aphidicolin and released from the blockage by replacing the medium with normal culture medium or with culture medium containing 2 mM 4-AP. 4-AP produced no significant inhibitory effect on cell cycle compared with control cells (P>0.05). Conclusions. In RPMI-8226, voltage-gated K+ channels are involved in proliferation and cell cycle progression its influence on the resting potential and cell volume may be responsible for this process; the inhibitory effect of the voltage-gated K+ channel blocker on RPMI-8226 cell proliferation is a phase-specific event

Mesoporous TiO

Mesoporous anatase TiO2 micro-nanometer composite structure was synthesized by solvothermal method at 180°C, followed by calcination at 400°C for 2 h. The as-prepared TiO2 was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and Fourier transform infrared spectrum (FT-IR). The specific surface area and pore size distribution were obtained from N2 adsorption-desorption isotherm, and the optoelectric property of the mesoporous TiO2 was studied by UV-Vis absorption spectrum and surface photovoltage spectra (SPS). The photocatalytic activity was evaluated by photodegradation of sole rhodamine B (RhB) and sole phenol aqueous solutions under simulated sunlight irradiation and compared with that of Degussa P-25 (P25) under the same conditions. The photodegradation preference of this mesoporous TiO2 was also investigated for an RhB-phenol mixed solution. The results show that the TiO2 composite structure consists of microspheres (∼0.5–2 μm in diameter) and irregular aggregates (several hundred nanometers) with rough surfaces and the average primary particle size is 10.2 nm. The photodegradation activities of this mesoporous TiO2 on both RhB and phenol solutions are higher than those of P25. Moreover, this as-prepared TiO2 exhibits photodegradation preference on RhB in the RhB-phenol mixture solution

Orai1 and Stim1 Mediate the Majority of Store-Operated Calcium Entry in Multiple Myeloma and Have Strong Implications for Adverse Prognosis

Background/Aims: Multiple myeloma (MM) is a plasma cell neoplasm which constitutes about 10% of all hematologic malignancies. Despite the development and application of novel agents, MM still undergoes an aggressive and incurable course in the vast majority of patients. Ca2+ is one of the critical regulators of cell migration. Ca2+ influx is essential for the migration of various types of cells including tumor cells. However, the role of store-operated calcium entry (SOC) channels, the only Ca2+ channels of non-excitable cells, has not yet been reported in MM cell survival. Methods: We evaluated the expression of Stim1 and Orai1 (two key regulators of SOC) in MM tissues and cell lines by immunohistochemical assay, quantitative real-time PCR assay and western blot. MM cell lines were pretreated with pharmacological blockers and siRNAs, and then MM cell proliferation, cell cycle arrest, and apoptosis were examined by FACS (flow cytometry) assay, and Annexin V-FITC/PI staining. The correlation between the expression of Stim1 (or Orai1) level and outcome in MM were assessed by using Progress Free Survival (PFS). Results: Stim1 and Orai1 were both abundantly expressed in MM tissue and MM cell lines. Inhibition of SOCE reduced MM cell viability, and induced cell cycle arrest and apoptosis. Stim1 or Orai1 silencing also reduced cell viability, caused cell apoptosis and cell cycle arrest in MM cell lines. Over-expression of Stim1/Orai1 in MM patients was closely associated with the clinical outcome of MM. Conclusion: The Stim1/Orai1-mediated signaling participates in the pathogenesis of MM, which represents an attractive target for future therapeutic intervention

Analyzing Ionosphere TEC and ROTI Responses on 2010 August High Speed Solar Winds

The high-speed solar winds stream (HSSWS) generated by coronal hole can produce large interplanetary magnetic field magnitude oscillations, leading to high latitude geomagnetic disturbances, and ionospheric responses as well. This paper has analyzed the global ionospheric total electron content (TEC) and rate of TEC index (ROTI) responses during the high speed solar winds stream occurred from 23 to 29 August, 2010. Ground Global Navigation Satellite System (GNSS) network was mainly used to investigate ionosphere TEC and ROTI behaviors. It has revealed that high latitudes and middle latitudes ionosphere suffered most during this event, with hemisphere asymmetry characteristics. Both TEC variations and ionosphere irregularities were analyzed. The HSSWS event brings to strong ionosphere irregularities represented by large ROTI enhancements at high latitudes. The concentrated ionosphere irregularities were closely related to the intensity of Auroral Electrojet enhancement activities. The ROTI enhancements at high latitudes, including polar cap, aurora, and sub-aurora are also influenced by solar zenith angle; all the prominent ROTI increments are observed in the ranges between 70° and 110° solar zenith angles; while the ROTI enhancements at low latitudes and equator are mostly found in the ranges between 130° and 170° solar zenith angles. The ionosphere disturbance triggered by the HSSWS is also noticed by some remarkable changes of F2 layer peak height. The work is contributing to the understanding of the theoretical coupling mechanism between high speed solar winds stream and magneto-ionosphere responses and provides a reference for space weather analysis and forecasting under similar events

Browning of Pig White Preadipocytes by Co-Overexpressing Pig PGC-1α and Mice UCP1

Background/Aims: Brown adipose tissue (BAT) is critical for mammals’ survival in the cold environment. BAT-dependent non-shivering thermogenesis is attributed to uncoupling protein 1 (UCP1)’s disengagement of oxidative phosphorylation from ATP synthesis and dissipates energy as heat. Thus individuals with a substantial amount of BAT are better equipped during cold stress and less likely to become obese. Recently, our laboratory has shown pig adipocytes have no UCP1 protein. The inability of newborn piglets to generate heat contributed to its high death rate. Repairing the genetic defect of UCP1 in pig adipocytes has implications in defending against cold for piglets and developing an alternative treatment for human obesity. Methods: Q-PCR, western blotting (WB) and oxygen consumption measurement were used to enable functional UCP1 protein in preadipocytes. Immunoprecipitation (IP), chromatin immunoprecipitation (CHIP), and dual-luciferase reporter assay system were used to clarify the thermogenesis mechanism of functional UCP1. Results: Only co-overexpressing mice UCP1 and pig PGC-1α increased not only the mitochondrial number but also the uncoupled respiration rate in the transfected pig adipocytes. The functional mice UCP1 increased the pig PGC-1α activity through the AMPK-SIRT1 pathway. The active form PGC-1α interacted with transcription factors Lhx8, Zic1, ERRα, and PPARα to regulate the expression of mitochondrial energy metabolism and adipocytes browning-related genes. Conclusion: Our data suggest a model in which pig PGC-1α and mice UCP1 work collaboratively to restore uncoupling respiration in pig preadipocytes. These results have great implications for piglet survival and developing an alternative treatment for human obesity in the future