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Aim: To evaluate the antibiofilm effect of proanthocyanidin (PA) solution as an irrigant against Enterococcus faecalis (E. faecalis) and its influence on the mechanical properties and biodegradation resistance of demineralized root dentine. Methodology: Enterococcus faecalis were introduced into human root dentine tubules by a serial centrifugation method and grown for 1 week. Dentine blocks infected with 1‐week‐old E. faecalis biofilms were treated with the following irrigants: sterile water (control), 2% chlorhexidine (CHX), 2% PA, 5% PA and 10% PA. After treatment, the live and dead bacteria proportions within E. faecalis biofilms were analysed using confocal laser scanning microscopy. To evaluate the biostability of fully demineralized dentine treated by the aforementioned irrigants, the elastic modulus and hydroxyproline release of human dentine incubated in collagenase solution were tested at baseline, after irrigant treatment and after biodegradation, respectively. Furthermore, the surface chemical bond of demineralized dentine collagen treated by various irrigants was characterized by X‐ray photoelectron spectroscopy (XPS). Statistical analysis was performed using one‐way anova and Tukey's post hoc multiple comparisons with the significance level at 5%. Results: The proportion of dead E. faecalis volume was significantly higher in the PA and CHX groups than that in the control group (P < 0.05). PA irrigation significantly increased the mechanical properties of demineralized dentine (P < 0.05), and the effect was enhanced with increasing PA concentration. CHX and PA groups had significantly less elasticity loss and hydroxyproline release (P < 0.05). The biomodification of dentine collagen by PA was verified by increased C‐O/C‐N peak percentage under C1s and C‐O peak percentage under O1s narrow‐scan XPS spectra. Conclusions: Proanthocyanidin killed E. faecalis within biofilms and enhanced the biostability of the collagen matrix of demineralized root dentine. It might be used as an auxiliary endodontic irrigant with antibiofilm and collagen‐stabilizing effects. [ABSTRACT FROM AUTHOR]

A theoretical model of a ferroelectric tunnel junction with multilevel polarization states is proposed, and the model is capable of achieving multiply ( i.e., four or eight) logic states by setting different polarization states in the ferroelectric thin film. The tunneling conductance that strongly depends on the barrier potential is calculated by applying a free-electron direct quantum tunneling method. The dependences of the conductance on bias voltage, barrier width, dielectric constant, and electric polarization are carefully investigated. The results may provide some insights into the realization of ultrahigh-density memory. [ABSTRACT FROM AUTHOR]

Niobium aluminum carbide ( Nb4 AlC3), as a member of the MAX phases, can retain its stiffness and strength up to over 1400°C, however, the strength at room temperature is relatively low. In this work, Nb5( Si, Al)3 was used to strengthen Nb4 AlC3. Nb4 AlC3- Nb5( Si, Al)3 composites with different amount of Nb5( Si, Al)3 were synthesized from the elemental powders by in situ hot-pressing/solid-liquid reaction synthesis process. The RT flexural strength was significantly improved from 370 MPa of monolithic Nb4 AlC3 to 432 MPa of Nb4 AlC3-15 vol% Nb5( Si, Al)3 composite without the degradation of its high-temperature mechanical properties. While a slightly decrease in fracture toughness occurs with the increment of Nb5( Si, Al)3 content. Meanwhile, Transmission electron microscopy ( TEM) observations reveal that the interfaces between Nb4 AlC3/ Nb4 AlC3, Nb4 AlC3/ Nb5( Si, Al)3, and Nb5( Si, Al)3/ Nb5( Si, Al)3 are free of amorphous layers, which is also beneficial to its high-temperature mechanical properties. [ABSTRACT FROM AUTHOR]

The cytogenetics of yellow grouper Epinephelus awoara was studied using multiple cytogenetic markers [Giemsa staining, C-banding, Ag-NORs and fluorescence in situ hybridization (FISH)]. Giemsa staining results showed that the karyotypic formula of E. awoara was 2 n = 48a, FN (fundamental number) = 48. Faint C-bandings were only detected at the centromeric regions of chromosome pair number 24, being almost indiscernible on the other chromosome pairs. After Ag-NOR staining, one pair of nucleolar organizer regions (NOR) was observed in the subcentromeric region of pair number 24. FISH results showed that 5S rDNA was located at a pair of medium-sized chromosomes, while 18S rDNA appeared at the same location in the subcentromeric region of pair number 24 where Ag-NORs were detected. The telomeric sequence (TTAGGG)n detected by FISH was located at both ends of each chromosome. The results suggested that E. awoara has retained general karyotypic structure stability during the evolutionary diversification process. [ABSTRACT FROM AUTHOR]

Summary We report a case of an infertile man with severe oligoasthenoteratozoospermia with a partial azoospermia factor b (AZFb) deletion and duplication region within chromosome Yp11.2. The hormonal profile was normal for serum concentrations of follicle-stimulating hormone, luteinizing hormone, testosterone and oestradiol. The patient, who showed a 46,XY karyotype, had an approximate 2.4 Mb inherited duplication region in Yp11.2 and a de novo partial AZFb deletion, which spanned 5.25 Mb including eight protein coding genes and four non-coding transcripts, but did not remove the RBMY gene family. Both proximal and distal breakpoints of the deletion were outside any palindromic region or inverted repeat sequence and intra-chromosomal non-allelic homologous recombination could not have been the deletion mechanism. The partial AZFb deletion in our case diminished sperm production, but did not completely extinguish spermatogenesis. Considering severe oligozoospermia, spermatozoa in the patient's ejaculate were used for intracytoplasmic sperm injection, resulting in two twin pregnancies. [ABSTRACT FROM AUTHOR]

Nb-doped Zr2[Al(Si)]4C5 solid solutions were prepared by in situ hot pressing method and their high-temperature oxidation behavior at 1000°-1300°C were investigated. The oxidation resistance of [Zr0.9(Nb0.1)]2[Al(Si)]4C5 solid solutions is improved remarkably compared with Zr2[Al(Si)]4C5 without dopant. The improved oxidation resistance is due to the formation of a more protective oxide scale consisting of (Zr,Nb)O2, Nb2 Zr6O17, Al2O3, and mullite, in which (Zr,Nb)O2 solid solution is more effective than ZrO2 in depressing the inward diffusion of oxygen. In addition, the decrease of cracks in the oxide scale above 1100°C in Nb-doped sample is also beneficial to the improved oxidation resistance. [ABSTRACT FROM AUTHOR]

In this study, a well-dispersed γ-Y2Si2O7 ethanol-based suspension with 30 vol% solid loading was prepared by adding 1 dwb% polyethylene imine dispersant, which allows feeble magnetic γ-Y2Si2O7 particles with anisotropic magnetic susceptibility to rotate in a 12 T strong magnetic field during slip casting, resulting in the development of a strong texture in green bodies. Pressureless sintering gives rise to more pronounced grain growth in the textured sample than in the untextured sample prepared without the magnetic field due to the rapid migration of the grain boundaries of the well-oriented grains, which was revealed by constant-heating-rate sintering kinetics. It was found that the use of two-step sintering is very efficient not only for inhibiting the grain growth but also for enhancing the texture. This implies that controlled grain growth is crucial for enhancing texture development in γ-Y2Si2O7. [ABSTRACT FROM AUTHOR]

Implicit solvent models based on the Poisson-Boltzmann (PB) equation are frequently used to describe the interactions of a biomolecule with its dielectric continuum environment. A novel, highly accurate Poisson-Boltzmann solver is developed based on the matched interface and boundary (MIB) method, which rigorously enforces the continuity conditions of both the electrostatic potential and its flux at the molecular surface. The MIB based PB solver attains much better convergence rates as a function of mesh size compared to conventional finite difference and finite element based PB solvers. Consequently, highly accurate electrostatic potentials and solvation energies are obtained at coarse mesh sizes. In the context of biomolecular electrostatic calculations it is demonstrated that the MIB method generates substantially more accurate solutions of the PB equation than other established methods, thus providing a new level of reference values for such models. Initial results also indicate that the MIB method can significantly improve the quality of electrostatic surface potentials of biomolecules that are frequently used in the study of biomolecular interactions based on experimental structures. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008 [ABSTRACT FROM AUTHOR]

A letter to the editor is presented reporting two cases of anaplastic lymphoma kinase expression in inflammatory myofibroblastic tumor of the bladder.

Ti3SiC2 has many salient properties including low density, high strength and modulus, damage tolerance at room temperature, good machinablity, and being resistant to thermal shock and oxidation below 1100°C. However, the low hardness and poor oxidation resistance above 1100°C limit the application of this material. The poor oxidation resistance at temperatures above 1100°C was because of the absence of protective layer in the scale and the presence of TiC impurity phase. TiC impurity could be eliminated by adding a small amount of Al to form Ti3Si(Al)C2 solid solutions. Although the high-temperature oxidation resistance was significantly improved for the Ti3Si(Al)C2 solid solutions, the strength at high temperatures was lost. One important way to enhance the high-temperature strength is to incorporate hard ceramic particles like SiC. In this article, we describe the in situ synthesis and simultaneous densification of Ti3Si(Al)C2/SiC composites using Ti, Si, Al, and graphite powders as the initial materials. The effect of SiC content on high-temperature mechanical properties and oxidation resistance were investigated. The mechanisms for the improved high-temperature properties are discussed. [ABSTRACT FROM AUTHOR]

In order to clarify the effectiveness of ultrasonication on vaccine delivery, juvenile sea bream, Pagrus major , were treated with eight different ultrasonic methods. A mixed vaccine against Vibrio alginolyticus and V. anguillarum was used to immunize the fish. The intensity and frequency of the ultrasound were 280 mW cm–2 and 35 kHz, respectively. The ultrasonic methods included continuous or pulsed ultrasound for 3 min, and continuous or pulsed ultrasound for 3 min before and/or after immersion for 3 min. Of all the eight ultrasonic methods tested, `pulsed ultrasound followed by immersion' and `immersion, pulsed ultrasound, and followed by immersion again' provided the best protection, which were comparable with protection of fish immunized by intraperitoneal injection. Moreover, the convenience of applying these two ultrasonic methods for immunization was comparable with the immersion method and was much better than intraperitoneal injection. If 2 × 108 CFU mL–1 of this mixed vaccine was used for vaccination repeatedly five times by ultrasonic methods, it could still produce good protection for the immunized sea bream. Therefore, the ultrasonic method is an effective and practical approach for fish vaccination on a large scale. [ABSTRACT FROM AUTHOR]

The structure of agkistrodotoxin crystallized under basic conditions has been determined at 2.8 A resolution by the molecular-replacement technique and refined to a crystallographic R factor of 0.194 and a free R factor of 0.260 with good stereochemistry. The molecular packing in the crystal differs from other PLA(2)s. The six molecules in the asymmetric unit form three dimers linked by Ca(2+) ions in a near-perfect six-ligand octahedral coordinating system. Extensive intermolecular hydrophobic interactions occur at the interfacial recognition site of each neurotoxin molecule, which provides an insight into phospholipase A(2)-membrane interactions. This hydrophobic interaction-induced molecular association along the interfacial recognition site suggests a self-protection mechanism of agkistrodotoxin.