NLO results with operator mixing for fully heavy tetraquarks in QCD sum rules

We study the mass spectra of $\overline{Q}Q\overline{Q}Q (Q = c, b)$ systems in QCD sum rules with the complete next-to-leading order (NLO) contribution to the pertabative QCD part of the correlation functions. Instead of meson-meson or diquark-diquark currents, we use diagonalized currents under operator renormalization. Numerical results show that the NLO corrections are very important for the $\overline{Q}Q\overline{Q}Q$ system, because they not only give significant contributions but also reduce parameter dependence and makes Borel platform more distinct, especially for the $\overline{b}b\overline{b}b$ in the $\overline{MS}$ scheme. We find that the operator mixing induced by NLO corrections is crucial to understand the color structure of the states. We use currents that have good perturbative convergence in our phenomenological analysis. We get three $J^{PC} = 0^{++}$ states, with masses $6.35^{+0.20}_{−0.17}$ GeV, $6.56^{+0.18}_{−0.20}$ GeV and $6.95^{+0.21}_{−0.31}$ GeV, respectively. The first two seem to agree with the broad structure around 6.2∼6.8 GeV measured by the LHCb collaboration in the $J/\psi J/\psi$ spectrum, and the third seems to agree with the narrow resonance X(6900). For the 2$^{++}$ states we find one with mass $7.03^{+0.22}_{−0.26}$ GeV, which is also close to that of X(6900), and another one around 7.3 GeV but with larger uncertainties

NLO results with operator mixing for fully heavy tetraquarks in QCD sum rules

We study the mass spectra of $\overline{Q}Q\overline{Q}Q (Q = c, b)$ systems in QCD sum rules with the complete next-to-leading order (NLO) contribution to the perturbative QCD part of the correlation functions. Instead of meson-meson or diquark-antidiquark currents, we use diagonalized currents under operator renormalization. We find that differing from conventional mesons $\overline{q}q$ and baryons $qqq$, a unique feature of the multiquark systems like $\overline{Q}Q\overline{Q}Q$ is the operator mixing or color configuration mixing induced by NLO corrections, which is crucial to understand the color structure of the states. Our numerical results show that the NLO corrections are very important for the $\overline{Q}Q\overline{Q}Q$ system, because they not only give significant contributions but also reduce the scheme and scale dependence and make Borel platform more distinct, especially for the $\overline{b}b\overline{b}b$ in the $\overline{MS}$ scheme. We use currents that have good perturbation convergence in our phenomenological analysis. With the $\overline{MS}$ scheme, we get three $J^{PC} = 0^{++}$ states, with masses $6.35^{+0.20}_{−0.17}$ GeV, $6.56^{+0.18}_{−0.20}$ GeV and $6.95^{+0.21}_{−0.31}$ GeV, respectively. The first two seem to agree with the broad structure around 6.2 ~ 6.8 GeV measured by the LHCb collaboration in the $J/\psi J/\psi$ spectrum, and the third seems to agree with the narrow resonance X(6900). For the 2$^{++}$ states we find one with mass $7.03^{+0.22}_{−0.26}$ GeV, which is also close to that of X(6900), and another one around $7.25^{+0.21}_{−0.35}$ GeV, which has good scale dependence but slightly large scheme dependence

Molecular simulation and spectroscopic studies on the interaction between perfluorohexadecanoic acid and human serum albumin

185-192In the present study, the interaction between Perfluorohexadecanoic acid (PFHxDA) and human serum albumin (HAS) was studied by fluorescence spectroscopy, molecular docking, dynamic simulation and circular dichroism (CD). The interaction character and the effect on human serum albumin conformation were measured by simulating the physiological condition (pH= 7.4). Experiments and simulation results revealed that PFHxDA molecules and HSA have regular fluorescence quenching, and the quenching mechanism is static quenching and non-radiative energy transfer. Thermodynamic analysis revealed the binding behavior was mainly governed by hydrophobic forces. Specific binding site experiments showed that the binding site of PFHxDA was a site I of HSA. The results from the CD spectrum demonstrated that PFHxDA changed the molecular conformation of HSA, which is consistent with the results obtained by molecular docking and dynamic simulation

Molecular simulation and spectroscopic studies on the interaction between perfluorohexadecanoic acid and human serum albumin

In the present study, the interaction between Perfluorohexadecanoic acid (PFHxDA) and human serum albumin (HAS) was studied by fluorescence spectroscopy, molecular docking, dynamic simulation and circular dichroism (CD). The interaction character and the effect on human serum albumin conformation were measured by simulating the physiological condition (pH= 7.4). Experiments and simulation results revealed that PFHxDA molecules and HSA have regular fluorescence quenching, and the quenching mechanism is static quenching and non-radiative energy transfer. Thermodynamic analysis revealed the binding behavior was mainly governed by hydrophobic forces. Specific binding site experiments showed that the binding site of PFHxDA was a site I of HSA. The results from the CD spectrum demonstrated that PFHxDA changed the molecular conformation of HSA, which is consistent with the results obtained by molecular docking and dynamic simulation

Green Tea Induces Annexin-I Expression in Human Lung Adenocarcinoma A549 Cells: Involvement of Annexin-I in Actin Remodeling

Green tea polyphenols exhibit multiple antitumor activities in various in vitro and in vivo tumor models, and the mechanisms of action are not clear. Previously, we found that green tea extract (GTE) regulates actin remodeling in different cell culture systems. Actin remodeling plays an important role in cancer cell morphology, cell adhesion, motility, and invasion. Using proteomic approaches, we found GTE-induced expression of annexin-I, a multifunctional actin binding protein, in these cell lines. In this study, we aimed to further define the functional role of GTE-induced annexin-I expression in actin remodeling, cell adhesion, and motility in lung adenocarcinoma A549 cells. We found that GTE stimulates the expression of annexin-I in a dose-dependent fashion. The GTE-induced annexin-I expression appears to be at the transcription level, and the increased annexin-I expression mediates actin polymerization, resulting in enhanced cell adhesion and decreased motility. Annexin-I specific interference resulted in loss of GTE-induced actin polymerization and cell adhesion, but not motility. In fact, annexin-I specific interference itself inhibited motility even without GTE. Together, annexin-I plays an important role in GTE-induced actin remodeling, and it may serve as a potential molecular target associated with the anticancer activities of green tea. © 2007 USCAP, Inc All rights reserved

Electroplating lithium transition metal oxides.

Materials synthesis often provides opportunities for innovation. We demonstrate a general low-temperature (260°C) molten salt electrodeposition approach to directly electroplate the important lithium-ion (Li-ion) battery cathode materials LiCoO2, LiMn2O4, and Al-doped LiCoO2. The crystallinities and electrochemical capacities of the electroplated oxides are comparable to those of the powders synthesized at much higher temperatures (700° to 1000°C). This new growth method significantly broadens the scope of battery form factors and functionalities, enabling a variety of highly desirable battery properties, including high energy, high power, and unprecedented electrode flexibility

KAEMPFEROL, A FLAVONOID COMPOUND FROM GYNURA MEDICA INDUCED APOPTOSIS AND GROWTH INHIBITION IN MCF-7 BREAST CANCER CELL

Background: Kaempferol, a natural flavonoid, has been shown to induce cancer cell apoptosis and cell growth inhibition in several tumors. Previously we have conducted a full investigation on the chemical constituents of Gynura medica, kaempferol and its glycosides are the major constituents of G. medica. Here we investigated the growth inhibition and apoptosis induction effect of kaempferol extracted from G. medica. Materials and Methods: The inhibition effects of kaempferol were evaluated by MTS assay and soft agar colony formation assay. Fluorescence staining and western blotting were be used to study the apoptosis. The structure was identified by 1H- NMR), 13C-NMR and ESI-MS analyses. Results: Our results showed that kaempferol’s inhibition of MCF-7 breast cancer cell growth may through inducing apoptosis and downregulation of Bcl2 expression. Conclusion: Kaempferol is a promising cancer preventive and therapeutic agent for breast cancer

A Comprehensive Model for Real Gas Transport in Shale Formations with Complex Non-planar Fracture Networks

A complex fracture network is generally generated during the hydraulic fracturing treatment in shale gas reservoirs. Numerous efforts have been made to model the flow behavior of such fracture networks. However, it is still challenging to predict the impacts of various gas transport mechanisms on well performance with arbitrary fracture geometry in a computationally efficient manner. We develop a robust and comprehensive model for real gas transport in shales with complex non-planar fracture network. Contributions of gas transport mechanisms and fracture complexity to well productivity and rate transient behavior are systematically analyzed. The major findings are: simple planar fracture can overestimate gas production than non-planar fracture due to less fracture interference. A “hump” that occurs in the transition period and formation linear flow with a slope less than 1/2 can infer the appearance of natural fractures. The sharpness of the “hump” can indicate the complexity and irregularity of the fracture networks. Gas flow mechanisms can extend the transition flow period. The gas desorption could make the “hump” more profound. The Knudsen diffusion and slippage effect play a dominant role in the later production time. Maximizing the fracture complexity through generating large connected networks is an effective way to increase shale gas production