Improved volume variable cluster model method for crystal-lattice optimization: effect on isotope fractionation factor.

The isotopic fractionation factor and element partition coefficient can be calculated only after the geometric optimization of the molecular clusters is completed. Optimization directly affects the accuracy of some parameters, such as the average bond length, molecular volume, harmonic vibrational frequency, and other thermodynamic parameters. Here, we used the improved volume variable cluster model (VVCM) method to optimize the molecular clusters of a typical oxide, quartz. We documented the average bond length and relative volume change. Finally, we extracted the harmonic vibrational frequencies and calculated the equilibrium fractionation factor of the silicon and oxygen isotopes. Given its performance in geometrical optimization and isotope fractionation factor calculation, we further applied the improved VVCM method to calculate isotope equilibrium fractionation factors of Cd and Zn between the hydroxide (Zn-Al layered double hydroxide), carbonate (cadmium-containing calcite) and their aqueous solutions under superficial conditions. We summarized a detailed procedure and used it to re-evaluate published theoretical results for cadmium-containing hydroxyapatite, emphasizing the relative volume change for all clusters and confirming the optimal point charge arrangement (PCA). The results showed that the average bond length and isotope fractionation factor are consistent with those published in previous studies, and the relative volume changes are considerably lower than the results calculated using the periodic boundary method. Specifically, the average Si-O bond length of quartz was 1.63 Å, and the relative volume change of quartz centered on silicon atoms was  - 0.39%. The average Zn-O bond length in the Zn-Al-layered double hydroxide was 2.10 Å, with a relative volume change of 1.96%. Cadmium-containing calcite had an average Cd-O bond length of 2.28 Å, with a relative volume change of 0.45%. At 298 K, the equilibrium fractionation factors between quartz, Zn-Al-layered double hydroxide, cadmium-containing calcite, and their corresponding aqueous solutions were [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] respectively. These results strongly support the reliability of the improved VVCM method for geometric optimization of molecular clusters.

Impurity effect on weak antilocalization in the topological insulator Bi2Te3.

We study the weak antilocalization (WAL) effect in topological insulator Bi(2)Te(3) thin films at low temperatures. The two-dimensional WAL effect associated with surface carriers is revealed in the tilted magnetic field dependence of magnetoconductance. Our data demonstrate that the observed WAL is robust against deposition of nonmagnetic Au impurities on the surface of the thin films, but it is quenched by the deposition of magnetic Fe impurities which destroy the π Berry phase of the topological surface states. The magnetoconductance data of a 5 nm Bi(2)Te(3) film suggests that a crossover from symplectic to unitary classes is observed with the deposition of Fe impurities.

Rs10757274 gene polymorphisms in coronary artery disease: A systematic review and a meta-analysis.

BACKGROUND: It has been reported the rs10757274 SNP (present on locus 9p21 in the gene for CDKN2BAS1) might be associated with susceptibility to coronary artery disease (CAD). Owing to mixed and inconclusive results, we conducted a meta-analysis to investigate the association between rs10757274 polymorphism and the risk of CAD. OBJECTIVES: The present study aimed to investigate the relationship between rs10757274 polymorphism and the risk of CAD. METHODS: All studies of the rs10757274 SNP with CAD that were published between 2007 and 2018 were retrieved from the PubMed database. Meta-analysis was performed with Stata 14.0 software. The effect size of the rs10757274 SNP with CAD risk was assessed based on the odds ratios (ORs) with calculation of 95% confidence interval (CI). RESULTS: Eleven studies including 52,209 subjects (cases: 7990, controls: 44,219) were included in the final data combination. Pooled overall analyses showed that rs10757274 (allele model: P < .001; dominant model: P < .001; recessive model: P < .001; Heterozygote codominant: P = .002; Homozygote codominant: P < .001) polymorphisms were significantly associated with the likelihood of CAD. Significant heterogeneity between individual studies appears in all 5 models. Further subgroup analyses revealed that rs10757274 polymorphisms were all significantly correlated with the likelihood of CAD and no heterogeneity were observed in West Asians. CONCLUSIONS: Our findings indicated that rs10757274 polymorphisms may serve as genetic biomarkers of CAD, especially in West Asians.

[Immune effects of three different programs for revaccination among adults of non- and hypo-responders to hepatitis B vaccine].

OBJECTIVE: To investigate the immune effects of three different programs for revaccination among adults of non- and hypo-responders to recombinant Hepatitis B vaccine. METHODS: Those who were once immunized with recombinant Hepatitis B vaccine more than one standard schedule (0, 1, and 6 months) in two years and negative for Hepatitis B markers were randomly given three-different projects for revaccination. 34 adults of A group were given GM-CSF 300 microg by subcutaneous injection for the first day, then 10 microg each time by intramuscular route for routine immune method. 33 adults of B group were given Hepatitis B vaccine 20 microg each time. 33 adults of C group were given Hepatitis B vaccine 10 microg each time. The blood samples were collected before the first injection and in 1, 2 and 8 months following the first injection to test Anti-HBs. RESULTS: At T1, the anti-HBs positive conversion rate of group A, B and C was 26.47%, 48.48% and 18.18% respectively (chi-2 = 7.20, P = 0.027). At T8, the anti-HBs positive conversion rate of group A (64.71%) and group B (75.76%) were higher than group C (39.39%), and there was significant difference (chi-2 = 9.07, P = 0.011). At T1, the anti-HBs level of group B (417.00 +/- 69.36) was higher than that of group A (203.74 +/- 79.56). At T2, the anti-HBs level of group B (458.17 +/- 64.09) was higher than that of group C (257.86 +/- 76.60). At T8, the anti-HBs level of group A (501.48 +/- 70.00) and group B (532.73 +/- 68.82) were higher than those of group C (256.12 +/- 75.39) (t =4.27, P = 0.0173). CONCLUSION: Schemes of augmentation doses of Hepatitis B vaccine and being combined with GM-CSF should be in effect for non- and hypo-responders to Hepatitis B vaccine.

Tunable interaction-induced localization of surface electrons in antidot nanostructured Bi2Te3 thin films.

Recently, a logarithmic decrease of conductivity has been observed in topological insulators at low temperatures, implying a tendency of localization of surface electrons. Here, we report quantum transport experiments on the topological insulator Bi2Te3 thin films with arrayed antidot nanostructures. With increasing density of the antidots, a systematic decrease is observed in the slope of the logarithmic temperature-dependent conductivity curves, indicating the electron-electron interaction can be tuned by the antidots. Meanwhile, the weak antilocalization effect revealed in magnetoconductivity exhibits an enhanced dominance of electron-electron interaction among decoherence mechanisms. The observation can be understood from an antidot-induced reduction of the effective dielectric constant, which controls the interactions between the surface electrons. Our results clarify the indispensable role of the electron-electron interaction in the localization of surface electrons and indicate the localization of surface electrons in an interacting topological insulator.

[Study on rhGM-CSF as adjuvant in revaccination among adults of non-and hyporesponders to hepatitis B vaccine].

OBJECTIVE: To investigate the effect of recombinant human granulocyte macrophage colony stimulating factor (rhGM-CSF) as adjuvant on immune response in adults of non-and hyporesponders to hepatitis B vaccine. METHODS: Those who were once immunized with recombined yeast gene hepatitis B vaccine more than one standard scheme in two years and negative for hepatitis B markers were randomly sorted as group A and group B. 33 adults of group A were given hepatitis B vaccine 10 microg each time. The immune procedure was 0, 1 and 6 month. 34 adults of group B were given rhGM-CSF 300 microg for the first day, then 10 microg each time for routine immune. The blood samples were collected before the first injection and in 1, 2 and 8 months (T1, T2, T8) following the first injection to test Anti-HBs. RESULTS: Anti-HBs positive conversion rates of group A and B at T8 was 39.39% and 64.71% respectively (P = 0.038). Anti-HBs levels of group B at T1, T2, T8 were (113.85 +/- 198.56) mIU/ml, (312.40 +/- 349.44) mIU/ml, (427.74 +/- 411.58) mIU/ml (P = 0.001). There was significant difference between group A and B in T8 Anti-HBs levels (P = 0.010). CONCLUSION: Better immune response was found in the group of rhGM-CSF with hepatitis B vaccine. So rhGM-CSF can induce the immune respond to hepatitis B vaccine.