Poly(etherimide)s and poly(esterimide)s containing azobenzene units: Characterization and study of photoinduced optical anisotropy

In this paper novel processable, photoresponsible aromatic polymers with imide rings and covalently boned azobenzene units are presented. Prepolymerization strategy based on polycondensation of two diamines with azobenzene group, that is, 2,4-diamino-4′-cyanoazobenzne and 2,4-diamino-4′-nitroazobenzene and two dianhydrides, was utilized for preparation of the new photochromic polyimides. The obtained polymers differ in the chemical structure of polymer backbone and the kind of substituents on azobenzene moieties. Polymers were characterized and evaluated by FT-IR, ¹H NMR, X-ray, UV-vis, DSC, and TGA methods. The synthesized azopolymers exhibited glass transition temperatures in the range of 140-170 °C, thermal stability with initial decomposition temperatures (T_d) in the range of 266-290 °C, and excellent solubilities in common organic solvents, providing optical-quality films. The light-induced optical anisotropy was studied in obtained polymers by photoinduced birefringence measurements. The birefringence was generated by the femtosecond pulses at 400 nm via a linear absorption of the trans-azobenzene. A large light-induced birefringence (Δn = 0.02) was achieved in poly(esterimide)s contrary to poly(etherimide)s. The birefringence exhibited a very stable behavior after switching off the writing light indicating a permanent storage capacity.     

Measuring the discrepancy between current and ideal spiritual and religious functioning in problem drinkers.

The idea that spiritual and religious functioning (SRF) is associated with alcohol misuse is generally supported, but problems with typical research methods limit the utility of findings. Problems in SRF were conceptualized as discrepancies between current and ideal SRF. Two separate studies were conducted to develop and evaluate a scale to measure the subjective importance and adequacy of aspects of SRF that seem to be associated with alcohol problems. The 1st study suggested that a questionnaire developed to evaluate self-reported ratings of current and ideal SRF is both internally consistent and temporally stable. In the 2nd study, the questionnaire was administered to persons seeking treatment for alcohol problems and persons who indicated that they had never sought treatment for an alcohol problem. Results indicate that those with a drinking problem were more likely to report substantial discrepancies between current and ideal SRF, supporting the validity of the measure as an indicator of problems in SRF. The usefulness of this method for treatment and research is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of Alloying Additions on Microstructure,Mechanical and Magnetic Properties of Rapidly Cooled Bulk Fe-B-M-Cu (M = Ti,Mo and Mn) Alloys

The influence of alloying additions on the microstructure, mechanical, and magnetic properties of bulk Fe₇₉B₂₀Cu₁, Fe₇₉B₁₆Ti₄Cu₁, Fe₇₉B₁₆Mo₄Cu₁ and Fe₇₉B₁₆Mn₄Cu₁ (at. pct) alloys was investigated. Nanocrystalline samples in the form of 3 mm rods were prepared directly by suction casting without additional heat treatment. Mössbauer spectroscopy, transmission electron microscopy and scanning electron microscopy studies confirmed that the investigated alloys consist α-Fe and Fe₂B nanograins embedded in an amorphous matrix. The addition of alloying elements, such as Ti, Mo and Mn to Fe₇₉B₂₀Cu₁ alloy increases the amount of amorphous phase and decreases the presence of Fe₂B phase in all examined alloys. The mechanical properties of the samples, such as hardness, elastic modulus, and elastic energy ratio, were analysed by an instrumented indentation technique performed on a 12 × 12 nanoindentation grid. These tests allowed to characterise the mechanical properties of the regions observed in the same material. For the Fe₇₉B₂₀Cu₁ alloy, the hardness of 1508 and 1999 HV, as well as Young’s modulus of 287 and 308 GPa, were estimated for the amorphous- and nanocrystalline-rich phase, respectively. The addition of Ti, Mo, and Mn atoms leads to a decrease in both hardness and elastic modulus for all regions in the investigated samples. Investigations of thermomagnetic characteristics show the soft magnetic properties of the studied materials. More detailed studies of magnetisation versus magnetic field curves for the Fe₇₉B_20−xM_xCu₁ (where x = 0 or 4; M = Ti, Mo, Mn) alloy, recorded in a wide range of temperatures, followed by the law of approach to magnetic saturation revealed the relationship between microstructure and magneto-mechanical properties.

     

Haemodynamics in the mouse aortic arch computed from MRI-derived velocities at the aortic root

Mice are widely used to investigate atherogenesis, which is known to be influenced by stresses related to blood flow. However, numerical characterization of the haemodynamic environment in the commonly studied aortic arch has hitherto been based on idealizations of inflow into the aorta. Our purpose in this work was to numerically characterize the haemodynamic environment in the mouse aortic arch using measured inflow velocities, and to relate the resulting shear stress patterns to known locations of high- and low-lesion prevalence. Blood flow velocities were measured in the aortic root of C57/BL6 mice using phase-contrast MRI. Arterial geometries were obtained by micro-CT of corrosion casts. These data were used to compute blood flow and wall shear stress (WSS) patterns in the arch. WSS profiles computed using realistic and idealized aortic root velocities differed significantly. An unexpected finding was that average WSS in the high-lesion-probability region on the inner wall was actually higher than the WSS in the low-probability region on the outer wall. Future studies of mouse aortic arch haemodynamics should avoid the use of idealized inflow velocity profiles. Lesion formation does not seem to uniquely associate with low or oscillating WSS in this segment, suggesting that other factors may also play a role in lesion localization.     

In Vitro Dissolution of Calcium Carbonate from the Chicken Eggshell: A Study of Calcium Bioavailability

In vitro dissolution is a major indicator of potential in vivo calcium absorption. It can be used to assess the bioavailability of Ca from different sources. The aim of this study was to analyze the in vitro dissolution of calcium carbonate from the eggshell samples collected before and after the incubation period. The samples of chicken eggshell were characterized by good dissolution, better than that of precipitated CaCO₃. The dissolution of the eggshell before incubation was found to be faster than that after incubation. Good dissolution (after 30 min both types of eggshells were dissolved in over 75%) of the chicken eggshell and the presence of other valuable microelements (boron, strontium) make this biomaterial an excellent source for dietary supplements production.     

Spindle assembly checkpoint-related meiotic defect in oocytes from LT/Sv mice has cytoplasmic origin and diminishes in older females

The spindle assembly checkpoint (SAC) ensures proper segregation of chromosomes by delaying anaphase onset until all kinetochores are properly attached to the spindle microtubules. Oocytes from the mouse strain LT/Sv arrest at the first meiotic metaphase (MI) due to, as reported recently, enormously prolonged activity of the SAC. We compared the dynamics of cyclin B1-GFP degradation, the process which is a measure of the SAC activity, in chromosomal and achromosomal halves of LT/Sv oocytes. In chromosome-containing oocyte halves arrested at MI, cyclin B1-GFP was not degraded indicating active SAC. However, in the halves lacking chromosomes, which is a condition precluding the SAC function, degradation always occurred confirming that MI arrest in LT/Sv oocytes is SAC dependent. Transferring the germinal vesicle (GV) from LT/Sv oocytes into the enucleated oocytes from wild-type mice resulted in the progression through meiosis one, indicating that a SAC-activating defect in LT/Sv oocytes is cytoplasmic, yet can be rescued by foreign cytoplasm. These results may help to define the etiology of the human infertility related to the oocyte MI arrest, indicating the involvement of the SAC as likely candidate, and point to GV transfer as the possible therapy. Finally, we found that majority of oocytes isolated from old LT/Sv mice complete the first meiosis. Reciprocal transfers of the GV between the oocytes from young and old LT/Sv females suggest that the factor(s) responsible for the reversal of the phenotype in oocytes from old mice is located both in the GV and in the cytoplasm.     

Thermal,optical, electrochemical,and electrochromic characteristics of novel polyimides bearing the Acridine Yellow moiety

A series of novel polyimides and copolyimides were obtained by combining 2,7-dimethylacridine-3,6-diamine with one of three aromatic dianhydrides: 1,4,5,8-naphthalenetetracarboxylic dianhydride, 4,4′-(4,4′-isopropylidene-diphenoxy)bis(phthalic anhydride) and 4,4′-tetraphthaloyl-bis(1,8-naphthalene dicarboxylic)dianhydride. The resultant polymers showed glass transition temperatures (T_g) in the range 209–331 °C and decomposition temperature (T_d) in the range of 370–475 °C. The optical properties, absorption and photoluminescence (PL) of the obtained polymers were investigated in solution and in the solid state as blends with inert poly(methyl methacrylate). The polymers dissolved in NMP emitted blue or green light with the maximum emission wavelength in the range of 438–512 nm, while emitting blue light in the solid state. The electrochemical behavior of the polyimides was studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). They exhibited electrochemical band gap in the range of 1.36–2.94 eV.     

Achievements in Thermosensitive Gelling Systems for Rectal Administration

Rectal drug delivery is an effective alternative to oral and parenteral treatments. This route allows for both local and systemic drug therapy. Traditional rectal dosage formulations have historically been used for localised treatments, including laxatives, hemorrhoid therapy and antipyretics. However, this form of drug dosage often feels alien and uncomfortable to a patient, encouraging refusal. The limitations of conventional solid suppositories can be overcome by creating a thermosensitive liquid suppository. Unfortunately, there are currently only a few studies describing their use in therapy. However, recent trends indicate an increase in the development of this modern therapeutic system. This review introduces a novel rectal drug delivery system with the goal of summarising recent developments in thermosensitive liquid suppositories for analgesic, anticancer, antiemetic, antihypertensive, psychiatric, antiallergic, anaesthetic, antimalarial drugs and insulin. The report also presents the impact of various types of components and their concentration on the properties of this rectal dosage form. Further research into such formulations is certainly needed in order to meet the high demand for modern, efficient rectal gelling systems. Continued research and development in this field would undoubtedly further reveal the hidden potential of rectal drug delivery systems.