Headache as a manifestation of myocardial infarction

A 33-year-old pregnant woman at 26 weeks gestation, who had a history of bipolar mood disorder, type I, was admitted to the hospital for hypomania and poorly controlled diabetes mellitus. The patient had had her first episode of affective illness at age 28, after the birth of her second child. After an initial postpartum depression, she had cycled into a manic state. She had subsequently been hospitalized seven times for acute mania. A combination of valproate and chlorpromazine had proven effective in managing most of her manic episodes, while her two most severe episodes had been successfully managed with bilateral ECT.     

Chondrogenic differentiation of mesenchymal stem cells in a leakproof collagen sponge

A three-dimensional culture of mesenchymal stem cells (MSCs) in a porous scaffold has been developed as a promising strategy for cartilage tissue engineering. The chondrogenic differentiation of MSCs derived from human bone marrow was studied by culturing the cells in a novel scaffold constructed of leakproof collagen sponge. All the surfaces of the collagen sponge except the top were wrapped with a membrane that has pores smaller than the cells to protect against cell leakage during cell seeding. The cells adhered to the collagen, distributed evenly, and proliferated to fill the spaces in the sponge. Cell seeding efficiency was greater than 95%. The MSCs cultured in the collagen sponge in the presence of TGF-β3 and BMP6 expressed a high level of genes encoding type II and type X collagen, sox9, and aggrecan. Histological examination by HE staining indicated that the differentiated cells showed a round morphology. The extracellular matrices were positively stained by safranin O and toluidine blue. Immunostaining with anti-type II collagen and anti-cartilage proteoglycan showed that type II collagen and cartilage proteoglycan were detected around the cells. These results suggest the chondrogenic differentiation of MSCs when cultured in the collagen sponge in the presence of TGF-β3 and BMP6.     

Stability and viability of synbiotic microgels incorporated into liquid,Greek and frozen yogurts

The viability of Lactobacillus acidophilus when co-encapsulated with fructooligosaccharides in alginate–gelatin microgels, for incorporation into liquid, Greek, and frozen yogurts, during storage and in vitro-simulated digestion was studied. Liquid yogurt provided the highest viability for the encapsulated probiotics during storage, followed by frozen and Greek formulations when compared to free probiotics, highlighting the influence of microencapsulation, yogurt composition, and storage conditions. Addition of up to 20% of probiotic (AG) and symbiotic (AGF) microgels did not cause significant changes in the liquid and frozen yogurts’ apparent viscosity (η_ap); however, it decreased η_ap for the Greek yogurt, indicating that microgels can alter product acceptability in this case. Both AG and AGF microparticles improved viability of cells face to gastric conditions for liquid and frozen yogurts, delivering cells in the enteric stage. Summarizing, liquid yogurt was the most appropriate for probiotic viability during storage, while frozen yogurt presented better protection along digestibility.     

Ferromagnetic GaN--Cr Nanowires

Using first-principles theory, we predict ferromagnetism in Cr-doped GaN nanowires irrespective of the sites that the Cr atoms occupy. This is in contrast to Mn-doped GaN nanowires in which the magnetic coupling between the Mn atoms is sensitive to the Mn--Mn and Mn--N distances, although the ground state of Mn-doped GaN nanowires is ferromagnetic. Each Cr atom carries a magnetic moment of about 2.5 micro(B). The magnetic moment at the N site, however, is small and is aligned antiferromagnetically to the moments at the Cr atom. The magnetization axis is perpendicular to the axis of the wire, but the anisotropy energy is rather small. The easy solubility of Cr in GaN and the lack of sensitivity of ferromagnetic coupling to Cr distribution suggest that Cr-doped GaN nanowires may be a more suitable system for applications in spintronics than Mn-doped GaN nanowires.     

Power-recycled resonant sideband extraction interferometer with polarization detection

Second-generation interferometric gravitational-wave detectors will use a technique called resonant sideband extraction (RSE) to improve the sensitivity in a narrow, tunable, frequency band. We present a configuration in which we use polarization detection to allow a continuously tunable power-recycled RSE interferometer for a control scheme similar to those of the first-generation detectors. A mathematical model describing this configuration and the results from a tabletop prototype are presented that demonstrate this configuration.     

Aluminum hydride coated single-walled carbon nanotube as a hydrogen storage medium

We report a first principle study on the hydrogen storage in Aluminum hydride (AlH₃) coated (5, 5) single-walled carbon nanotube (SWCNT). Our study indicates that a SWCNT coated with Aluminum hydride (Alane – AlH₃) can bind up to four hydrogen molecules. At half coverage of AlH₃, the hydrogen storage capacity of the SWCNT is 8.3 wt%. The system with full coverage is also studied and it is found that, even though the hydrogen storage capacity increases, the binding of H₂ is weak. All the H₂ adsorption is molecular with H–H bond length of 0.756 Å. Our result on a full molecular adsorption of hydrogen via light metal hydride is new and it leads to a practically viable storage process.     

Application of photon emission technique to the determination of micro-fracture behavior in glass fiber-reinforced epoxy matrix composite

A photon emission behavior in a notched plane woven fabric glass fiber-reinforced epoxy matrix composite has been examined through tensile testing of a single-edge-notched composite specimen. Emitted photons during the test were detected and a spectroscopic analysis was also performed on the detected photons to determine the source of the emission. Direct observation of the fracture process of the composite reveals that bundle unit fiber fracture occurs from a notch tip and the fracture accompanies characteristic load drop in the load-displacement curve. Photons are detected about 15–30 ms after the onset of the load drop, which corresponds to the photon emission occurring at the beginning of a bundle unit fiber pullout from the matrix. The emission mechanism is determined to be gaseous ionization discharging of nitrogen molecules, which are contained in ambient air, at a debonded interface. Application of DC potential to the specimen enhances photon intensity and the technique allows photon imaging. Detected photon imaging clearly shows the area of interfacial frictional sliding. It is concluded that the photon emission technique is effective tool to determine interface debonding and sliding behavior in glass fiber-reinforced epoxy matrix composite.     

Correlation between microhardness and electronic charge density of hafnium hydrides

Quantitative Vickers microhardnesses for α + δ′-, δ′-, δ-, δ + ?- and ?-phase hafnium hydrides (HfH_x; 1.46 ≤ x ≤ 2.02) and deuterides (HfD_x; 1.55 ≤ x ≤ 1.94) at room temperature have been measured using a Vickers hardness tester. The Vickers microhardnesses of the HfH_x and HfD_x gradually decreased with an increase of the hydrogen concentration, and those for 1.46 ≤ x ≤ 1.70 were higher than that of α-phase metallic Hf. It was revealed by a first-principles calculation as well as an X-ray photoelectron spectroscopy (XPS) measurement that the hydrogen concentration dependence of the microhardnesses for HfH_x and HfD_x was ascribed mainly in terms of its influence on charge transfer from Hf 5d to H 1s and reduction of cohesive energy.     

Atomistic structure and strain relaxation in Czochralski-grown Si<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Ge<Subscript>1−<Emphasis Type="Italic">x</Emphasis></Subscript> bulk alloys

The local atomistic structure in bulk Si_xGe_1−x alloys in the whole composition range 0 < x < 1 was investigated experimentally and theoretically. By extended X-ray absorption fine structure measurements in Czochralski-grown bulk SiGe crystals it is found that bulk SiGe is a random mixture and that the Ge–Ge, Ge–Si and Si–Si bond lengths maintain distinctly different lengths and vary in a linear fashion as a function of alloy composition across the entire composition range 0 < x < 1, in good agreement with expectations derived from the ab-inito electronic structure calculations. The results indicate that SiGe is a typical disorder material and that the bond lengths and bond angles are distorted with alloy composition in SiGe.