Clear evidence for element partitioning effects in a Ti-6Al-4V alloy by the first-principles phase field method.

Ti-6 wt% Al-4 wt% V (Ti64) is an α + ß titanium alloy, in which the alloying components strongly affect the mechanical properties. In this report, element partitioning effects in Ti64 are investigated by using the first-principles phase field (FPPF) method, which has recently been proposed by our group. In the FPPF method, the local free energy is calculated using a cluster expansion method in combination with density functional theory and the temperature effect is incorporated using potential renormalization theory. We have succeeded in identifying enrichment of Al (V) in the α (ß) phase, i.e., the clear evidence for the element partitioning effects of Al and V, without using any thermodynamical parameter. The transformation of the ß phase and the α phase in microstructure is investigated by varying the V and Al concentrations by a small amount. Our results are in excellent agreement with the recent experimental results, showing the validity of the FPPF method for ternary alloys.

A theoretical exploration of the intermolecular interactions between resveratrol and water: a DFT and AIM analysis.

The polyphenolic compound resveratrol, classified under stilbenes, offers a broad range of health advantages, including neuroprotection and playing a role in autophagy in the nervous system. However, resveratrol has poor water solubility and is soluble in the gel phase in liposomal membranes. The main aim of this work was to understand the nature of the interactions between resveratrol and water molecules. In the present study, we used the dispersion corrected density functional theory (DFT) method to study hydrogen bonding interactions. Eight different geometries of resveratrol-water complexes were identified by optimizing the geometries by placing water at various locations. We observed the two lowest energy structures to be isoenergetic. In most complexes, water interaction occurs with phenolic hydrogen as all the phenolic hydroxyl groups have identical Vs,max values. Energy decomposition analysis shows that the dispersion contribution was minimal in these complexes, while electrostatic and orbital contributions were larger. Complex formation between water and the resveratrol molecule results in a blue shift in the vibrational frequency, along with an increase in intensity due to the transfer of electron density. The hydrogen bonds in the resveratrol-water complexes have closed-shell interactions with a medium-to-strong bonding nature. Noncovalent index analysis of the complexes shows that, in addition to hydrogen bonding, electrostatic and van der Waal's interactions play a key role in stabilizing the complexes. Graphical abstract Noncovalent index analysis showing that, in addition to hydrogen bonding, electrostatic and van der Waal's interactions play a major role in stabilizing resveratrol-water complexes.

Identification of genes upregulated in the inflamed colonic lesions of Crohn's disease.

To identify the molecular mechanism which primarily plays a role in the pathogenesis of Crohn's disease (CD) without prior hypothesis, differential display method was employed to detect differentially expressed genes between the inflamed and uninflamed colonic samples from one patient with CD. The mRNA levels of these genes were subsequently semi-quantitated in affected and unaffected tissues from six patients using reverse transcriptase polymerase chain reaction (RT-PCR). Six genes including long form FLICE inhibitory protein (FLIP(L)) were found to be consistently overexpressed in the inflamed colonic CD tissues. Immunohistochemical studies revealed that FLIP(L) expressing cells were lamina propria lymphocytes (LPLs). The present study suggested that overexpression of FLIP(L) in the LPLs may be involved in the pathogenesis of CD through defective activation-induced cell death. In addition, this study provided evidence for a possible role of several previously unsuspected genes in the pathogenesis of CD.

Muscle-filling procedure for transsphincteric fistulas.

PURPOSE: During transsphincteric fistula surgery, laying open the entire fistula track can cause grave damage. Thus, a surgical procedure that excises the primary abscess only is preferable. However, the primary abscess of a transsphincteric fistula is located in the postanal space. When creating an appropriate drainage wound after excision of the primary abscess, damage to the drainage wound itself can be severe. This article illustrates an alternative procedure. METHODS: We have developed a new method in which we excise only the primary abscess of a transsphincteric fistula and use the muscle flap at the bottom of the wound to fill in the dead space left by the excision. This procedure takes advantage of the availability of the muscle flap and allows for a smaller wound and faster wound healing. RESULTS: During the past 17 years, during which 328 transsphincteric fistula procedures have been performed using the muscle-filling technique, we have experienced a recurrence rate of only 1.5 percent (5 cases). CONCLUSION: The muscle-filling technique is an effective alternative procedure for transsphincteric fistulas.

AlGaAs/GaAs optically controlled wave-plate modulator.

We demonstrate an AlGaAs/GaAs multiple-quantum-well optically controlled electro-optic wave-plate modulator that uses integrated optics. For operation as an optically controlled switch, output amplitude contrast ratios of greater than 300:1 are typically obtained with signal beam throughputs of 34% and an extrapolated switching speed of 1.5 ns. For applications as an optically controlled wave plate, we have measured the linear, r(41), and quadratic, R(11)-R(12), electro-optic coefficients of the waveguide at the signal wavelengths and the device photo-generated current sensitivity at the control beam wavelength.

Enhanced optooptical light deflection using cavity resonance.

The efficiency of optooptieal light deflection by nondegencrote four-wave mixing can be increased significantly by placing the grating in a resonant cavity. Theory and experiment are presented for linear and ring cavities. Efficiency improvement by an order of magnitude is predicted, and improvements by a factor of 5.6 hove been demonstrated.