No abstract

In this paper we propose a new method to study tunneling problems in the presence of phonons at zero temperature. We have found that, by taking account of the nonadiabatic effect induced by coupling with a tunneling particle, the ground states of phonons can be described by displaced squeezed states, instead of by the displaced oscillator states given in the adiabatic approximation. On one hand, in these new ground states the suppression effect of the phonon overlapping integral on the renormalized tunneling parameter is more alleviated than that in displaced oscillator states. On the other hand, the condition for the localization-dislocalization transition of the tunneling particle is modified in the displaced squeezed states compared with the previous studies.

The hydrothermal reaction of CuSO(4), 1,2-benzenedicarboxylate (phth), and 1,2-bis(imidazol-1-yl)ethane (bime) yields the two-dimensional metal-organic framework {[Cu(5)(bime)(mu(3)-OH)(2)(phth)(4)](H(2)O)(2)}(n) (1), which is based on the pentanuclear copper(II) cluster [Cu(5)(mu(3)-OH)(2)(phth)(4)] and shows dominant ferromagnetic interactions within the pentanuclear cluster.

The car body structures of modern trains are often formed of extruded aluminium panels. Their acoustic properties, particularly the sound transmission loss, have an important influence on the interior acoustic environment. In order to study the acoustic performance of extruded panels, their Sound Transmission Loss (STL) is studied using the coupled Wavenumber Finite Element method (WFE) and Wavenumber Boundary Element method (WBE). The damping of a typical structure is first measured in the laboratory to give suitable input values for the model. The predicted STL is compared with corresponding measurements of the sample panel, with good agreement above 400 Hz. Based on the validated model, an extensive parametric study is carried out to investigate the effect of different reinforcement rib styles on the STL. The effect of using extruded panels with rectangular, triangular and trapezoidal truss-core sections is studied in detail. Among the parameters studied, the number of bays in a given width has a great influence on the sound insulation. Considering practical use, both the mass and stiffness of each case are also considered. To give increased understanding of the STL behaviour, the dispersion curves are also studied. It is found that structures with better STL usually have fewer free wavenumbers below the acoustic wavenumber. For the same number of structural bays, a panel with triangular stiffening has the highest strength but also the largest mass, whereas a structure with rectangular stiffening has the least strength and lowest mass. In the evaluation, the weighted STL R w and the spectral adaptation term C tr are considered. The results are also considered relative to a mass law adjustment of the STL. It is found that the three cases which give the best results are a triangular rib panel with 4 or 5 bays in a 1 m width, and a trapezium case with 5 bays and inclination angle 25°. These have an R w that is 2~6 dB better than the reference panel, a smaller mass and a higher stiffness. Keywords sound transmission loss; extruded panels; wavenumber finite element; wavenumber boundary element; dispersion 65 Frequency, Hz STL, dB Rw(dB) Case 2-1 30.1 Case 2-2 28.5 Case 2-3 26.3 Figure B.6 Effect of width on diffuse field STL of cases 2-1~2-3 Case 2-1 Case 2-2 Case 2-3 Case 3-1 Case 3-2 Case 3-3

No abstract

Background: Titanium (Ti) implants are widely used clinically, but peri-implantitis remains one of the most common and serious complications. Healthy integration between gingival tissue and the implant surface is critical to long-term success in dental implant therapy. The objective of this study was to investigate how different concentrations of immobilized fibroblast growth factor 2 (FGF2) on the titania nanotubular surface influence the response of human gingival fibroblasts (HGFs). Methods: Pure Ti metal was anodized at 20 V to form a vertically organized titanium dioxide nanotube array on which three concentrations of FGF2 (250 ng/mL, 500 ng/mL, or 1000 ng/mL) were immobilized by repeated lyophilization. Surface topography was observed and FGF2 elution was detected using enzyme-linked immunosorbent assay. The bioactivity changes of dissolvable immobilized FGF2 were measured by methyl-thiazolyl-tetrazolium assay. Behavior of HGFs was evaluated using adhesion and methyl-thiazolyl-tetrazolium bromide assays. Results: The FGF2 remained for several days on the modified surface on which HGFs were cultured. Over 90% of the dissolvable immobilized FGF2 had been eluted by Day 9, whereas the FGF2 activity was found to diminish gradually from Day 1 to Day 9. The titania nanotubular surface with an optimal preparing concentration (500 ng/mL) of FGF2 immobilization exhibited improved HGF functions such as cellular attachment, proliferation, and extracellular matrix-related gene expression. Moreover, significant bidirectional as well as concentration-and time-dependent bioactivity was observed. Conclusion: Synergism of the FGF2-impregnated titanium dioxide nanotubular surface revealed good gingival-implant integration, indicating that these materials might have promising applications in dentistry and other biomedical devices.

No abstract

Insufficient intake of dairy products is a nutritional problem of concern in China. However, the knowledge, attitude, and practice of consuming dairy products in the Chinese population remain unknown. A total of 1739 subjects from eight cities in China participated in this study. A questionnaire was used to measure knowledge of and attitude toward dairy. A semi-food intake frequency questionnaire was used to obtain the frequencies and amount of different kinds of dairy product intake. Calcium and protein intake were investigated within one 24-hour period of dietary recall. The results showed that questions related to lactose intolerance had the highest unknown rate and the lowest accuracy. Males, subjects with a lower education level, lower monthly family income (<3000 yuan), lower monthly family food expenditure (<1000 yuan), and lower personal monthly expenditure on dairy products (<10 yuan) had a significantly lower knowledge score. For attitude, 42.7 percent of subjects had self-perceived insufficient intake of dairy. While 15.2 percent of subjects reported experiencing lactose intolerance symptoms, 29.5 percent did not know the reasons. In practice, the median (25th, 75th) intake of dairy products was 71.4 (0.0, 200.0) g/day. A significantly lower intake of dairy and low-fat or fat-free dairy products was shown in subjects with poor dairy knowledge. For the perception of lactose intolerance, the lowest intake was shown in the “unsure” group. In conclusion, knowledge gaps and self-perception bias regarding dairy products exist in Chinese urban adults and these are associated with the quantity and quality of dairy intake.