Structures and nonlinear optical properties of the endohedral metallofullerene-superhalogen compounds Li@C60-BX4 (X = F, Cl, Br).

It has recently been demonstrated that superatoms, which can exhibit behaviors reminiscent of atoms in the periodic table, might have synthetic utility, and represent potential building blocks for the assembly of novel, nanostructured materials [Science 2004, 304, 84-87; Science 2005, 307, 231-235; J. Phys. Chem. C 2009, 113, 2664]. In this work, a new type of endohedral metallofullerene-superhalogen compound, Li@C60-BX4 (X = F, Cl, Br), is proposed and characterized using density functional theory. The electron transfer from Li@C60 to BX4 contributes greatly to the Li@C60-BX4 compound formation. Such compounds exhibit considerable stabilities with large binding energies and ionization potentials, as well as large HOMO-LUMO gaps. The investigation of the nonlinear optical (NLO) properties of Li@C60-BX4 reveals a strong dependence of the static first hyperpolarizability, ß0, on the atomic number of the involved halogen atom X. This means that one can enhance the first hyperpolarizabilities of the endohedral metallofullerene by introducing superhalogens. The present investigation may promote the development of novel nanomaterials with unusual properties (i.e. NLO properties), and enrich the knowledge of chemical bonds (for example, long-range interactions between trapped atoms in a C60 cage and the outside superatom motif).

Quantum mechanical design and structures of hexanuclear sandwich complex and its multidecker sandwich clusters (Li6)n([18]annulene)n+1 (n = 1-3).

By means of density functional theory, a hexanuclear sandwich complex [18]annulene-Li6-[18]annulene which consists of a central Li6 hexagon ring and large face-capping ligands, [18]annulene, is designed and investigated. The large interaction energy and HOMO-LUMO gap suggest that this novel charge-separated complex is highly stable and may be experimentally synthesized. In addition, the stability found in the [18]annulene-Li6-[18]annulene complex extends to multidecker sandwich clusters (Li6)n([18]annulene)n+1 (n = 2-3). The energy gain upon addition of a [18]annulene-Li6 unit to (Li6)n-1([18]annulene)n is pretty large (96.97-98.22 kcal/mol), indicating that even larger multideckers will also be very stable. Similar to ferrocene, such a hexanuclear sandwich complex could be considered as a versatile building block to find potential applications in different areas of chemistry, such as nanoscience and material science.

Increased Th17 cell frequency concomitant with decreased Foxp3+ Treg cell frequency in the peripheral circulation of patients with carotid artery plaques.

OBJECTIVE AND DESIGN: We investigated a possible imbalance between T helper (Th)17 and CD4+ CD25+ forkhead/winged helix transcription factor (Foxp3) T regulatory (Treg) cells in patients with carotid artery plaques. MATERIAL OR SUBJECTS: From November 2009 to September 2010, we enrolled 126 males and 104 females with mean age 68.24 ± 6.71 years. TREATMENT: Based on carotid artery sonography, the 230 subjects were categorized into three groups: plaque negative; stable plaques; and unstable plaques. METHODS: Th17 and Treg cell frequencies, relevant plasma cytokines (IL-17, IL-6, IL-23, and TNF-α), and RORγt mRNA levels were determined. RESULTS: Compared to plaque negative, Th17 cells, Th17-related cytokines (IL-17, IL-6, IL-23, and TNF-α), and RORγt mRNA levels were higher with stable plaques, and highest with unstable plaques. The opposite trend was found for Treg cells, Treg-related cytokines (IL-10 and TGF-ß1), and Foxp3 mRNA. Th17 cell frequencies were significantly negatively correlated with Treg cell frequencies. CONCLUSIONS: Our investigation demonstrated that there is a Th17/Treg functional imbalance in patients with unstable carotid atherosclerotic plaques. Th17 cells may promote atherogenesis, while Treg cells may have a protective role against atherosclerosis plaques. An imbalance of Th17/Treg cells may offer a new direction for the treatment of atherosclerosis.

[A cohort study on the predictive value of factors influencing cardio-cerebro vascular death among people over 40 years of age].

OBJECTIVE: To explore the factors influencing cardio-cerebro vascular death events among people over 40 years of age in Shandong area, China. METHODS: Baseline survey was carried out in 1991. A total number of 11,008 adults over 40 years old had been studied in Shandong province. Data on cardiocerebro death was collected. The correlation between influencing factors and cardio-cerebro vascular death events was analyzed by Cox regression model. RESULTS: Totally, 434 cardio-cerebro death events occurred among the 11,008 subjects during the 8-year follow-up study. Cardio-cerebro death events were related to systolic blood pressure, diastolic blood pressure, smoking, stroke history and age. Data from Cox regression analysis showed that the relative risk (RR) for cardio-cerebro vascular death events increased by 2.862 [95% confidence interval (CI): 1.976-4.144] times for those people having stroke history. When systolic blood pressure, diastolic blood pressure increased by every 10 mm Hg, the relative risk for cardio-cerebro vascular death events increased by 1.171 (95% CI: 1.033-1.328), 1.214 (95% CI: 1.044-1.413) respectively. it was found that a 1.239 (95% CI: 1.088-1.553) times higher in smokers than non-smokers on relative risk for cardio-cerebro vascular death events. However, the predictive values of the influencing factors for cardio-cerebro vascular death were different among population of different years of age. The relative risk for cardio-cerebro vascular death events increased by 1.366 (95% CI: 1.102-1.678) times for each 10 mm Hg increase of diastolic blood pressure in 40-59 years old population. However, the effect was taken place by systolic blood pressure in 60-74 years old population,with a relative risk of 1.201 (95% CI: 1.017-1.418) for each 10 mm Hg increase. Age seemed the only significant factor for cardio-cerebro vascular death events on population aged more than 75 years old. Conclusion The predictive values of the risk factors were different among age groups. The different risk factors should be taken care according to the difference of age.

[Improving the nutritional value of plant foods through transgenic approaches].

The most nutrients required in the human diet come from plants. The nutritional quality of plant products affects the human healthy. The advance of molecular cloning and transgenic technology has provided a new way to enhance the nutritional value of plant material. Transgenic modification of plant nutritional value has progressed greatly in the following aspects: improving the quality, composition and levels of protein, starch and fatty acid in different crops; increasing the levels of antioxidants (e.g. carotenoids and flavonoids); breeding the new type of plants with medical value for human. To date, many transgenic plants with nutritional enhancement have been developed. These transgenic plant products could be directly used as human diet or as valued materials in developing the "functional food" with especial nutritional quality and healthy effects after they are approved by a series of evaluations on their safety and nutritional efficiency for human being. We designed new zinc finger transcription factors (ZFP-TFs) that can specifically down-regulate the expression of the endogenous soybean FAD2-1 gene which catalyzes oleic acid to linoleic acid. Seed-specific expression of these ZFP-TFs in transgenic soybean somatic embryos repressed FAD2-1 transcription and increased significantly the levels of oleic acid, indicating that the engineered ZFP-TFs are capable of regulating fatty acid metabolism and modulating the expression of endogenous genes in plants.