Solvent resistant thermoplastic aromatic poly(imidesulfone) and process for preparing same

A process for preparing a thermoplastic poly(imidesulfone) is disclosed. This resulting material has thermoplastic properties which are generally associated with polysulfones but not polyimides, and solvent resistance which is generally associated with polyimides but not polysulfones. This system is processable in the 250 to 350 C range for molding, adhesive and laminating applications. This unique thermoplastic poly(imidesulfone) is obtained by incorporating an aromatic sulfone moiety into the backbone of an aromatic linear polyimide by dissolving a quantity of a 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA) in a solution of 3,3'-diaminodiphenylsulfone and bis(2-methoxyethyl)ether, precipitating the reactant product in water, filtering and drying the recovered poly(amide-acid sulfone) and converting it to the poly(imidesulfone) by heating

Process for preparing solvent resistant, thermoplastic aromatic poly(imidesulfone)

A process for preparing a thermoplastic poly(midesulfone) is disclosed. This resulting material has thermoplastic properties which are generally associated with polysulfones but not polyimides, and solvent resistant which is generally associated with polyimides but not polysulfones. This system is processable in the 250 to 350 C range for molding, adhesive and laminating applications. This unique thermoplastic poly(imidesulfone) is obtained by incorporating an aromatic sulfone moiety into the backbone of an aromatic linear polyimide by dissolving a quantity of a 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA) in a solution of 3,3'-diaminodiphenylsulfone and bis(2-methoxyethyl)ether, precipitating the reactant product in water, filtering and drying the recovered poly(amide-acid sulfone) and converting it to the poly(imidesulfone) by heating

Identification of Angiotensin I-converting enzyme Inhibitory Activities from traditional Mongolian fermented milk products

Several angiotensen-converting enzyme (ACE) inhibitory peptites have been detected in milk products. There are many traditional milk products in Mongolia. For this study, some Mongolian milk products were collected, and the ACE inhibitory activities of these samples were tested; an active fraction was found in aaruul made from mare’s milk. After purification by dialysis and HPLC, the active fractions were isolated. The molecular weight of the active component was 362.05 M, as determined by mass spectrometry. An authentic standard was used to determine the IC50 value of the inhibitory activity. From 5’-GMP is not much higher than that of the active peptide in sour milk and some flavonoids. However, this is the first report that shows that 5’ –GMP inhibits ACE activity. These results will provide useful information for the development of hypertension therapy agents.DOI: http://dx.doi.org/10.5564/mjc.v12i0.175 Mongolian Journal of Chemistry Vol.12 2011: 65-6

Phonon-phonon interactions and phonon damping in carbon nanotubes

We formulate and study the effective low-energy quantum theory of interacting long-wavelength acoustic phonons in carbon nanotubes within the framework of continuum elasticity theory. A general and analytical derivation of all three- and four-phonon processes is provided, and the relevant coupling constants are determined in terms of few elastic coefficients. Due to the low dimensionality and the parabolic dispersion, the finite-temperature density of noninteracting flexural phonons diverges, and a nonperturbative approach to their interactions is necessary. Within a mean-field description, we find that a dynamical gap opens. In practice, this gap is thermally smeared, but still has important consequences. Using our theory, we compute the decay rates of acoustic phonons due to phonon-phonon and electron-phonon interactions, implying upper bounds for their quality factor.Comment: 15 pages, 2 figures, published versio

A rice ABC transporter, OsABCC1, reduces arsenic accumulation in the grain

Arsenic (As) is a chronic poison that causes severe skin lesions and cancer. Rice (Oryza sativa L.) is a major dietary source of As; therefore, reducing As accumulation in the rice grain and thereby diminishing the amount of As that enters the food chain is of critical importance. Here, we report that a member of the Oryza sativa C-type ATP-binding cassette (ABC) transporter (OsABCC) family, OsABCC1, is involved in the detoxification and reduction of As in rice grains. We found that OsABCC1 was expressed in many organs, including the roots, leaves, nodes, peduncle, and rachis. Expression was not affected when plants were exposed to low levels of As but was up-regulated in response to high levels of As. In both the basal nodes and upper nodes, which are connected to the panicle, OsABCC1 was localized to the phloem region of vascular bundles. Furthermore, OsABCC1 was localized to the tonoplast and conferred phytochelatin-dependent As resistance in yeast. Knockout of OsABCC1 in rice resulted in decreased tolerance to As, but did not affect cadmium toxicity. At the reproductive growth stage, the As content was higher in the nodes and in other tissues of wild-type rice than in those of OsABCC1 knockout mutants, but was significantly lower in the grain. Taken together, our results indicate that OsABCC1 limits As transport to the grains by sequestering As in the vacuoles of the phloem companion cells of the nodes in rice.open117318Ysciescopu

Peierls Mechanism of the Metal-Insulator Transition in Ferromagnetic Hollandite K2Cr8O16

Synchrotron X-ray diffraction experiment shows that the metal-insulator transition occurring in a ferromagnetic state of a hollandite K$_2$Cr$_8$O$_{16}$ is accompanied by a structural distortion from the tetragonal $I4/m$ to monoclinic $P112_{1}/a$ phase with a $\sqrt{2}\times\sqrt{2}\times 1$ supercell. Detailed electronic structure calculations demonstrate that the metal-insulator transition is caused by a Peierls instability in the quasi-one-dimensional column structure made of four coupled Cr-O chains running in the $c$-direction, leading to the formation of tetramers of Cr ions below the transition temperature. This furnishes a rare example of the Peierls transition of fully spin-polarized electron systems.Comment: Phys. Rev. Lett., in press, 5 pages, 3 figure

Assessing Health Conditions and Medication Use Among the Homeless Community in Long Beach, California

Objective: Persons experiencing homelessness are a vulnerable population and are at increased risk for morbidity and all-cause mortality compared to the general population. This study sought to evaluate medication use, regular physician visits, and identify health conditions among the homeless population of Long Beach, California. Methods: Two brown bag medication review events were held at homeless shelters in the Long Beach area. Demographic information, medication use, and comorbid disease states were obtained through surveys. Findings: Three-fourths of the cohort (95 participants) consisted of males, and the average age of participants was 48 years. Psychiatric disorders and cardiovascular disease were the most common disease states reported at 32% and 46%, respectively and so were medications used in treating these chronic diseases. Medication adherence was found to be a significant problem in this population, where more than 30% of patients were nonadherent to medications for chronic diseases. Furthermore, foot problems, hearing and vision difficulties constitute the most commonly overlooked health problems within the homeless population. Conclusion: Based on this and other similar finding, we must accept that the homeless represent a vulnerable population, and that because of this fact, more programs should be focused at improving availability and access to health care among the homeless. Regarding the high number of reported health problems in the study, more studies are needed and more studies should incorporate screening for foot, hearing, and vision issues, both to increase awareness and to provide an opportunity for devising possible solutions to these highly preventable conditions

Properties of Ridges in Elastic Membranes

When a thin elastic sheet is confined to a region much smaller than its size the morphology of the resulting crumpled membrane is a network of straight ridges or folds that meet at sharp vertices. A virial theorem predicts the ratio of the total bending and stretching energies of a ridge. Small strains and curvatures persist far away from the ridge. We discuss several kinds of perturbations that distinguish a ridge in a crumpled sheet from an isolated ridge studied earlier (A. E. Lobkovsky, Phys. Rev. E. 53 3750 (1996)). Linear response as well as buckling properties are investigated. We find that quite generally, the energy of a ridge can change by no more than a finite fraction before it buckles.Comment: 13 pages, RevTeX, acknowledgement adde