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Selected AbstractsChemInform Abstract: A Rare Multi-Coordinate Tellurite, NH4ATe4O9×2H2O (A: Rb or Cs): The Occurrence of TeO3, TeO4, and TeO5 Polyhedra in the Same Material.CHEMINFORM, Issue 47 2008Jun-Ho Kim Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Fine structure of unusual spermatozoa and spermiogenesis of the mite Megisthanus floridanus Banks, 1904 (Acari: Gamasida: Antennophorina)ACTA ZOOLOGICA, Issue 4 2002Gerd Alberti Abstract The aflagellate spermatozoa of the gamasid mite Megisthanus floridanus are characterized by a large vacuole which contains a cytoplasmic column protruding into the vacuole from the region defined as the posterior part of the cell. The membrane of the column and the inner membrane of the posterior part of the cytoplasmic mantle (outer sheath) surrounding the vacuole bear numerous so-called cellular processes. However, most of the outer sheath is reduced and represented solely by a very thin membrane-like envelope. The posterior part of the cell bears extensive folds. The cell, or, more precisely, the column, shows a deep posterior invagination. This invagination contains extracellular material composed of thin filaments or strands. Peripheral folds emerging from the posterior rim of the cell form a thin-walled tube that contains the same material as the invagination. The elongated nucleus is attached to a peculiar acrosomal complex consisting of a flat acrosomal cisterna that parallels most of the cell membrane, an attachment cone, and a short acrosomal filament which is embedded in a narrow canal within the nucleus. The spermatozoa of M. floridanus represent a peculiar version of the vacuolated type of sperm known to be plesiomorphic within the anactinotrichid Acari. Some details of spermiogenesis are described and consequences for phylogenetic and systematic considerations are discussed. [source] Influence of processing conditions on the weld line in doubly injection-molded glassy polycarbonate and polystyrene: Microindentation hardness studyADVANCES IN POLYMER TECHNOLOGY, Issue 1 2005M. Boyanova Abstract The microhardness (H) technique has been used to characterize the quality of the weld line in injection-molded tensile bars from a two-component machine in which both melt streams from the same material can be independently controlled. More specific, the influence of melt temperature and indentation location (closer or further from the sample edge parallel to the injection direction and across the weld line) has been followed on polycarbonate (PC) and polystyrene (PS) glassy samples. For both polymers at lower melt temperatures, a strong H decrease (between 15 and 50%) followed by a sharp increase in a narrow distance (around 0.10 mm), is observed. When the melt temperature increases up to 300°C (for PC) and 270°C (for PS), a much smaller H decrease is observed in the central part of the samples. However, closer to the tensile bar edges (2 mm) the weld line remains undetectable by microhardness measurements. The present results reveal that the processing temperature affects the broadening of the weld line through the conditions for effective mutual interdiffusion of chains from the two fronts coming from opposite sides. © 2005 Wiley Periodicals, Inc. Adv Polym Techn 24:14,20, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20028 [source] Comparison of cytotoxic and inflammatory responses of photoluminescent silicon nanoparticles with silicon micron-sized particles in RAW 264.7 macrophagesJOURNAL OF APPLIED TOXICOLOGY, Issue 1 2009Jonghoon Choi Abstract Photoluminescent silicon nanoparticles have a bright and stable fluorescence and are promising candidates for bio-imaging, cell staining and drug delivery. With increasing development of nanotechnology applications for biomedicine, an understanding of the potential toxicity of nanoparticles is needed to assess safety concerns for clinical applications. The objective of this study was to compare biological responses of silicon nanoparticles (SNs, 3 nm diameter) with silicon microparticles (SMs, ,100,3000 nm diameter) in cultured murine macrophages (RAW 264.7) using standard protocols for assessing cytotoxicity/cell viability and inflammatory responses developed for micron-sized particles. SNs and SMs were exposed to macrophages with and without addition of endotoxin lipopolysaccharide (LPS), a positive inducer of tumor necrosis factor-alpha (TNF- ,), interleukin 6 (IL-6), and nitric oxide (NO). Cytotoxicity was assayed using the dye exclusion and MTT assays. Cell supernatants were assayed for production TNF- ,, IL-6 and NO. SNs at concentrations ,20 µg ml,1 exhibited no cytotoxicity or inflammatory responses; however, SNs and SMs >20 and 200 µg ml,1, respectively, increased cytotoxicity compared with controls. SMs induced concentration-related increases in TNF- , and IL-6 production; in contrast, the production of these cytokines was shown to decrease with increasing concentrations of SNs. NO production was not induced by SNs or SMs alone. Fluorescence microscopy demonstrated that SNs were associated with the macrophages, either internalized or attached to cell membranes. In conclusion, evaluating differences in biological responses for nanoparticles compared with microparticles of the same material may help improve tests to assess biological responses of nanoparticles that may be used in biomedical applications. Copyright © 2008 John Wiley & Sons, Ltd. [source] Irreversible Perforations in Vertebral Trabeculae?,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 7 2003X Banse In human cancellous bone, osteoclastic perforations resulting from normal remodeling were generally considered irreversible. In human vertebral samples, examined by backscatter electron microscopy, there was clear evidence of bridging of perforation defects by new bone formation. Hence trabecular perforations may not be irreversible. Introduction: Preservation of the trabecular bone microarchitecture is essential to maintain its load-bearing capacity and prevent fractures. However, during bone remodeling, the osteoclasts may perforate the platelike trabeculae and disconnect the structure. Large perforations (>100 ,m) are generally considered irreversible because there is no surface on which new bone can be laid down. In this work, we investigated the outcome of these perforations on human vertebral cancellous bone. Materials and Methods: Using backscatter electron microscopy, we analyzed 264 vertebral bone samples from the thoracic and lumbar spine of nine subjects (44,88 years old). Nine fields (2 × 1.5 mm) were observed on each block. Several bone structural units (BSUs) were visible on a single trabecula, illustrating a dynamic, historical aspect of bone remodeling. A bridge was defined as a single and recent BSU connecting two segments of trabeculae previously separated by osteoclastic resorption. They were counted and measured (length and breadth, ,m). Results and Conclusion: We observed 396 bridges over 2376 images. By comparison, we found only 15 microcalluses on the same material. The median length of the bridge was 165 ,m (range, 29,869 ,m); 86% being longer than 100 ,m and 35% longer than 200 ,m. Their breadth was 56 ,m (range, 6,255 ,m), but the thinnest were still in construction. Bridges were found in all nine subjects included in the study, suggesting that it is a common feature of normal vertebral bone remodeling. These observations support the hypothesis that perforation could be repaired by new bone formation. and hence, might not be systematically irreversible. [source] Overexpression of MLH-1 and psoriasin genes in cutaneous angiofibromas from tuberous sclerosis complex patientsJOURNAL OF CUTANEOUS PATHOLOGY, Issue 9 2006Michelangelo La Placa Background:, Tuberous sclerosis complex (TSC) is associated with mutations in two likely tumor-suppressor genes (TSC1 and TSC2) and characterized by the development of tumor-like growths (angiofibromas) in a variety of tissues and organs, particularly brain and skin. Methods:, Employing a DNA-microarray assay, able to detect mRNA production from 1176 different basic genes, we analyzed the gene-expression levels in a cutaneous hamartoma sample from a TSC patient. Altered gene expressions detected by microarray technology were further checked by quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) in the same material and in cutaneous hamartoma samples obtained from five other TSC patients. Results:, The results obtained by the microarray technology in one hamartoma specimen, confirmed by the RT-PCR results obtained in the same material and in five other hamartoma specimens, demonstrated that TSC-related angiofibromas exhibit significant mRNA overexpression of two genes, represented by MLH-1 and psoriasin. Conclusions:, The overexpression of MLH-1, which codes for a DNA mismatch repair protein, and psoriasin, which codes for a specific chemoattractant factor for CD4+ T cells, implicated in the pathogenesis of inflammatory skin disease, and expressed in excess during abnormal pathways of cell growth, may shed light on the pathogenesis of the proliferative skin lesion. [source] SENSORY QUALITY CRITERIA FOR FIVE FISH SPECIES PREDICTED FROM NEAR-INFRARED (NIR) REFLECTANCE MEASUREMENTJOURNAL OF FOOD QUALITY, Issue 5 2001KARIN WARM ABSTRACT Sensory profiling and Near-Infrared (NIR) reflectance analysis were carried out on cod (Gadus morhua), saithe (Pollachius virens), rainbow trout (Salmo gardineri), herring (Clupea harengus) and flounder (Platichthys flessus). A nine-member trained panel performed the profiling on cooked fillet samples and NIR was measured on the same material as whole, raw fish and raw fillet. For each species, samples varied in storage time (1,11 days in ice at OC) and season (spring, autumn and winter). One descriptive vocabulary was developed, containing 46 descriptive words altogether: 7 for appearance, 15, odor, 16, taste and 8 texture words. Multivariate data analysis was used to reduce the 46 words to 18, covering the main systematic variations in appearance, odor, taste and texture in conformance with a previous study. The same 18 sensory attributes were modeled by NIR measurements on whole, new fish and fillet. The predictive results showed explained variances to be higher for appearance and texture rhan for odor, and lowest for taste. The results indicate that NIR spectroscopy of raw fish as a supplement to sensory analysis might be useful as a rapid tool in Quality Monitoring for measuring the sensory parameters of appearance and texture of cooked fish. [source] Inferencing skills of adolescent readers who are hearing impairedJOURNAL OF RESEARCH IN READING, Issue 3 2003John Doran Two experiments examined the inferencing abilities of a group of adolescents who were hearing impaired compared with a group of hearing children matched approximately for chronological age. The first experiment used on-line methods and suggests that pupils who are hearing impaired are less efficient at drawing inferences. When they do so correctly, they draw inferences automatically as the text is encountered in a similar manner to the hearing pupils. In the second experiment, the same material was presented to the hearing-impaired adolescents in British Sign Language. However, from the results obtained, it is not possible to comment on how the information is processed when it is presented manually, and suggestions are made on ways this might be further investigated. It is suggested that the difficulties encountered by the students who are hearing impaired, when reading implicit material, reflect the relative impoverishment of their experiential backgrounds. [source] Preparation, Characterization, and Photocatalytic Properties of CaNb2O6 NanoparticlesJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 2 2009In-Sun Cho CaNb2O6 nanoparticles with a size range of 30,50 nm were synthesized by heat treatment at 600°C after a solvothermal process and their optical and photocatalytic properties were investigated. The prepared powders were characterized by X-ray powder diffractometer, field-emission scanning electron microscope, transmission electron microscope, UV-Vis diffuse reflectance spectroscopy, Fluorescence spectroscopy, and Raman spectroscopy. Compared with a powder of the same material prepared by a solid-state reaction (SS) method, the nanoparticles exhibited a higher Brunauer,Emmett,Teller (BET) surface area, more efficient light absorption, and enhanced photocatalytic activity for producing H2 from pure water under UV irradiation. The photoluminescence spectra revealed that a radiative recombination process is dominant in the powder prepared by the SS method (strong blue emission at 300 K) under UV light irradiation, while no obvious emission was observed in the nanoparticles. This decrease of the radiative recombination as well as the higher optical absorption ability and higher BET surface area resulting from the reduced dimensionality led to enhanced photocatalytic activity of the nanoparticles. [source] Mass Gain due to the Chemical Recombination of Water in Fired Clay BrickJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 10 2008Shaun D. Savage Mass gain due to recombination of water in freshly fired brick ceramic is compared with that in both bulk and powdered samples of the same material following reheating to 500°C. In all cases the gain in mass occurs in two distinct stages both linear with (time)1/4, the first (Stage I) ending at t,1.5 h followed by a second stage (Stage II), which continues indefinitely. The powdered ceramic following reheating shows a dramatic increase in reactivity with a mass gain in the first stage equivalent to that which would be achieved by the bulk ceramic in over 2000 years. [source] Measurement of in situ Monomer Sorption in Poly(propylene)MACROMOLECULAR RAPID COMMUNICATIONS, Issue 18 2004Jochem T. M. Pater Abstract Summary: An experimental method has been developed to compare the amount of monomer absorbed in freshly produced poly(propylene) with the amount of monomer absorbed in the same material after degassing. It has been found that propylene sorption in freshly produced poly(propylene) is significantly higher than the sorption in the same but degassed polymer. The difference depends on the degree of drying and is time-dependent. This fact can be an explanation for reduced activity often observed in the transition from liquid- to gas-phase polymerization. Pressure profile during the pressure-swing part of the experiment. [source] Small perforated shorted-patch antennaMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 4 2005H. K. Kan Abstract We present a patch antenna that is small in area as a result of combining two size-reduction procedures: using a single shorting pin and perforating the patch conductor. The new printed antenna is 30% smaller in area than a conventional shorted (single-post) patch and 93% smaller than a traditional probe-fed patch antenna, all designed on the same material. The measured 10-dB return loss of the shorted perforated patch is 8.1% and the gain varies from 0.5 to 1 dBi across this bandwidth. The overall size of the antenna (including ground plane) is 0.13,0 × 0.12,0 × 0.07,0. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 319,321, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20810 [source] Moments of phonon density of states spectra and characteristic phonon temperatures of wide band gap materialsPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 12 2006Roland Pässler Abstract We have re-digitized a variety of phonon density of states (PDOS) spectra, that have been published by different researchers for the wide band gap materials diamond, SiC, BN, AlN, GaN, ZnO, ZnS, and ZnSe, including calculations of the respective first- and second-order moments. Notwithstanding the obvious differences in concrete shapes of spectra presented for one and the same material by different authors, the respective magnitudes of estimated moments have been found in most cases to be nearly the same (to within uncertainties of some few%). Anticipated differences between phonon temperatures, ,eff, that are effective in controlling the observable temperature dependences of fundamental energy gaps and the respective average phonon temperatures, ,P, are seen to be throughout smaller than ±10%. The estimated high-temperature limits of Debye temperatures, ,D(,), are found to be significantly higher (by factors of order 1.4) than ,P. As a remarkable heuristic finding revealed by our numerical and analytical studies we can further state that, for SiC, AlN, GaN, ZnO, ZnS, and ZnSe, the individual ,D(,) values are nearly equal (within ±5%) to the respective average optical (LO/TO) phonon temperatures pertaining to the upper sections of the corresponding PDOS spectra. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Low-loss planar optical waveguides fabricated from polycarbonatePOLYMER ENGINEERING & SCIENCE, Issue 10 2009Jian-guo Chen Low-loss slab waveguides with air as overcladding based on a high glass transition temperature (Tg) polycarbonate were fabricated through spin-coating. Optical absorption and thermo-optic coefficient were investigated by spectrum analysis and prism coupler, respectively. Prism-coupling and charge-coupled device (CCD) camera imaging method were exploited together to evaluate the overall propagation loss of slab waveguides. The measured results of prism coupler were 0.282 dB/cm at 1310 nm and 0.197 dB/cm at 632.8 nm, whereas 0.07 dB/cm at 632.8 nm using CCD camera imaging method. Based on the same material, straight ridge waveguides and multimode interference couplers were fabricated through photolithograph and reactive ion etching, revealing smooth sides and excellent definition. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers. [source] Interfacial instabilities in coextrusion flows of low-density polyethylenes: Experimental studiesPOLYMER ENGINEERING & SCIENCE, Issue 5 2000Costas Tzoganakis A fundamental investigation into the interfacial instability phenomenon was performed. Coextrusion experiments were carried out using well-characterized low-density (LDPE) resins in an effort to gain a better understanding of interfacial instability phenomena. The resins used were chosen carefully and included materials of high and low viscosity as well as broad and narrow molecular weight distributions (MWD). The experiments involved the coextrusion of either the same material in both layers or various combinations of the four materials and the focus of the work was to elucidate the effects of flow rates, molecular weight (MW) and MWD on interfacial instability. The effect of the geometry at the point where the materials merged was also investigated. It was concluded that there are essentially two types of interfacial instabilities and that the MW had the strongest effect on the occurrence of the "zig-zag" instability due to high interfacial stress while the breadth of the MWD had a strong effect on the appearance of the "wave" instability. Broad MWD materials had a greater tendency to exhibit interfacial instability, which is more due to layer ratio than processing conditions or die geometries. The results suggest that the origin of the "wave" type of interfacial instability is due to an extreme extensional deformation of the minor layer at the merge point and that the viscoelastic properties of adjacent layers determine the instability development. [source] Discussion of Dr Hinz's contributionTHE INTERNATIONAL JOURNAL OF PSYCHOANALYSIS, Issue 2 2003Joyce McDougall The author places herself in the position of the analyst to ,listen' to a session reported by her German colleague, Dr Hinz; her interpretation of the material presented gives greater importance to the striving of the analysand to have his ,productions' appreciated than the analyst's interpretation of the negative transference aspects attributed to the same material. [source] 6-Dimethoxymethyl-1-methoxycarbonylbicyclo[3.1.0]hex-2-ene-2-carboxylic acidACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2000Satomi Niwayama The title compound, C12H16O6, prepared by a standard synthetic method, was determined by single-crystal X-ray crystallography to exist with a cyclopropane ring fused to a cyclopentene ring. Comparison of the unit-cell dimensions and space group of this material with those of a crystal of the same material prepared using a route involving pig liver esterase hydrolysis shows them to be identical. [source] Highly Permeable Genipin-Cross-linked Gelatin Conduits Enhance Peripheral Nerve RegenerationARTIFICIAL ORGANS, Issue 12 2009Ju-Ying Chang Abstract Here we have evaluated peripheral nerve regeneration with a porous biodegradable nerve conduit (PGGC), which was made from genipin-cross-linked gelatin. To examine the effect of pores, nonporous genipin-cross-linked gelatin conduit (GGC) was considered as the control. Both the PGGC and the GGC were dark blue in appearance with a concentric and round lumina. The PGGC featured an outer surface with pores of variable size homogeneously traversing, and a partially fenestrated inner surface connected by an open trabecular meshwork. The GGC had a rough outer surface whereas its inner lumen was smooth. Both PGGCs and GGCs had similar hydrophilicity on condition of the same material and cross-linking degree. The porosity of PGGCs and GGCs was 90.8 ± 0.9% and 24.3 ± 2.9%, respectively. The maximum tensile force of the GGCs (0.12 ± 0.06 kN) exceeded that of the PGGCs (0.03 ± 0.01 kN), but the PGGCs had a higher swelling ratio than GGCs at 0.5, 1, 3, 6, 12, 24, 48, 60, 72, and 84 h after soaking in deionized water. Cytotoxic testing revealed the soaking solutions of both of the tube composites would not produce cytotoxicity to cocultured Schwann cells. After subcutaneous implantation on the dorsal side of the rat, the PGGC was degraded completely after 12 weeks of implantation whereas a thin tissue capsule was formed encapsulating the partially degraded GGC. Biodegradability of both of the tube groups and their effectiveness as a guidance channel were examined as they were used to repair a 10 mm gap in the rat sciatic nerve. As a result, fragmentation of the GGC was still seen after 12 weeks of implantation, yet the PGGC had been completely degraded. Histological observation showed that numerous myelinated axons had crossed over the gap region in the PGGCs after 8 weeks of implantation despite only few myelinated axons and unmyelinated axons mostly surrounded by Schwann cells seen in the GGCs. In addition, the regenerated nerves in the PGGCs presented a significantly higher nerve conductive velocity than those in the GGCs (P < 0.05). Thus, the PGGCs can not only offer effective aids for regenerating nerves but also accelerate favorable nerve functional recovery compared with the GGCs. [source] Cervical occlusion in women with cervical insufficiency: protocol for a randomised, controlled trial with cerclage, with and without cervical occlusion,BJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 5 2007NJ Secher Objective, To evaluate the effect of double cerclage compared with a single cerclage. Design, Randomised, controlled multicentre trial. Setting, Ten different countries are participating with both secondary and tertiary centres. The countries participating are Denmark, Sweden, Germany, United Kingdom, Spain, South Africa, Australia and India. This gives both a broad spectrum of diversity global and local. We expect a total of 242 women enrolled per year. Population, Prophylactic study: 1History of cervical incompetence/insufficiency. (Delivery 15 to <36 weeks.) 2Congenital short cervix (secondary to maternal administration of diethyl stilbestrol) or traumatic/surgical damage rendering the vaginal approach difficult (e.g. conisation). 3Cervical suture applied in previous pregnancy, successful outcome. 4Previous failed cerclage. Therapeutic study: 5Secondary cerclage: Short cervix, without the membranes being exposed to the vagina. 6Tertiary cerclage: Short cervix, membranes exposed to the vagina. Observational study: Eligible women who refuse to be randomised will participate in an observational study. 7Repeat/requested cervical occlusion. Methods, The women will be randomised between a single (vaginal or abdominal) and a double cerclage. The cervical cerclage (McDonald or Shirodkar) as well as the abdominal suture will be performed with the same material and technique normally used by the participating department. Those randomised to the double cerclage will have their external os closed with a continuous nylon 2-0/3-0 suture, in addition to the standard single cerclage. Local guidelines concerning antibiotics, Heparin, bed rest, tocolytics etc. are followed and recorded in the follow-up form. Main outcome measures, Primary endpoint is take home baby rate. The secondary endpoints are gestational age at delivery, incidence of preterm birth (<34+0 days) and number of days in neonatal unit. [source] Carcinogenic potential of commonly used hernia repair prostheses in an experimental modelBRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 3 2004P. Witherspoon Background: The purpose of this study was to assess the carcinogenic potential of commonly used hernia repair prostheses in an animal model. Methods: Three types of prosthetic material (monofilament polypropylene, multifilament polypropylene and expanded polytetrafluoroethylene) were implanted in CBA/H mice. Flat (1 cm2) and rolled pieces of the same material were placed subcutaneously in either flank, and a further flat piece was placed in the preperitoneal space. Owing to a high incidence of mesh extrusion in the polypropylene groups, the study protocol was modified to allow only preperitoneal placement of the material. A fourth, control, group had the pockets for the prostheses created but no material implanted. After modification of the protocol there were approximately 60 mice in each group. The mice were followed for 2 years, then killed and assessed histologically for tumour development. Results: No sarcoma developed at the site of mesh implantation in any of the groups. Conclusion: This study indicates that the risk of sarcoma formation at the site of hernia repair prostheses is very low. Copyright © 2004 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source] An Organic Light-Emitting Diode with Field-Effect Electron Transport,ADVANCED FUNCTIONAL MATERIALS, Issue 1 2008S. Schols Abstract We describe an organic light-emitting diode (OLED) using field-effect to transport electrons. The device is a hybrid between a diode and a field-effect transistor. Compared to conventional OLEDs, the metallic cathode is displaced by one to several micrometers from the light-emitting zone. This micrometer-sized distance can be bridged by electrons with enhanced field-effect mobility. The device is fabricated using poly(triarylamine) (PTAA) as the hole-transport material, tris(8-hydroxyquinoline) aluminum (Alq3) doped with 4-(dicyanomethylene)-2-methyl-6-(julolindin-4-yl-vinyl)-4H-pyran (DCM2) as the active light-emitting layer, and N,N,-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (PTCDI-C13H27), as the electron-transport material. The obtained external quantum efficiencies are as high as for conventional OLEDs comprising the same materials. The quantum efficiencies of the new devices are remarkably independent of the current, up to current densities of more than 10 A cm,2. In addition, the absence of a metallic cathode covering the light-emission zone permits top-emission and could reduce optical absorption losses in waveguide structures. These properties may be useful in the future for the fabrication of solid-state high-brightness organic light sources. [source] Direct Patterning of Organic-Thin-Film-Transistor Arrays via a "Dry-Taping" ApproachADVANCED MATERIALS, Issue 12 2009Shuhong Liu Dry patterning of a variety of solution- and vapor-deposited small-molecule organic semiconductors using adhesive tape is demonstrated. This technique allows direct fabrication of large-area arrays of bottom-contact high-performance organic- thin-film field-effect transistors with self-aligned electrodes. These patterned devices exhibit significantly higher on/off ratios and lower parasitic leakage currents than control unpatterned devices of the same materials. [source] Proliferative activity and genetic changes in adrenal cortical tumors examined by flow cytometry, fluorescence in situ hybridization and immunohistochemistryINTERNATIONAL JOURNAL OF UROLOGY, Issue 2 2005KOUSUKE TAKEHARA Abstract Background: To determine differences in biological features among different adrenal tumors, we investigated the DNA ploidy, numerical chromosomal aberration and proliferative activity in human adrenal cortical neoplasms. Methods: Our study included six adrenal cortical adenomas with Cushing syndrome, 12 adenomas with hyperaldosteronism, three non-functioning adenomas and three adrenal cortical carcinomas. Isolated nuclei from frozen samples were used for fluorescence in situ hybridization (FISH) analysis, and formalin-fixed, paraffin-embedded tissues from the same materials were analyzed using flow cytometry (FCM) for DNA ploidy. Sections from paraffin blocks were stained immunohistochemically with antibodies against Ki-67 and p53. For FISH analysis, we used an ,-centromeric enumeration probe for chromosome 17. Results: The mean Ki-67 labeling index (LI) of adrenal cortical carcinomas was markedly higher than that of adrenal cortical adenomas (209.4 vs 8.7). In functional adrenal cortical adenomas, the LI was significantly lower in adenomas with hyperaldosteronism than in those with Cushing syndrome (P = 0.004), although FCM results indicated that tetraploid patterns were more frequently observed in the former type. Tumor size was significantly smaller in adenomas with hyperaldosteronism than in those with Cushing syndrome (P = 0.004). Chromosome 17 showed disomy in all adrenal cortical adenomas, whereas chromosome 17 abnormalities were found in two of three adrenal cortical carcinomas. Only the latter two cases strongly expressed p53 protein. Conclusions: Our study characterized various biological features of benign and malignant adrenal cortical tumors. The use of a combination of markers might provide additional information to assist our understanding of the clinical behavior of an individual adrenal cortical tumor. [source] Chemical study of triterpenoid resinous materials in archaeological findings by means of direct exposure electron ionisation mass spectrometry and gas chromatography/mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 11 2006Francesca Modugno A systematic study of standard triterpenes (, -amyrine, oleanolic acid, betulin, lupeol, betulinic acid and lupenone) and of raw resinous materials (frankincense resin, mastic resin and birch bark pitch) was performed using direct exposure electron ionisation mass spectrometry (DE-MS) and gas chromatography/mass spectrometry (GC/MS). DE-MS provides a mass spectral fingerprint of organic materials in a few minutes which highlights the compounds that are the main components in the sample. The application of principal component analysis (PCA) on DE-MS data in the mass ranges m/z 181,260 and m/z 331,500, corresponding to the fragmentation of triterpenoid molecules, enabled us to distinguish between different triterpenoid materials such as mastic resin, frankincense resin and birch bark pitch, and to graphically plot the resinous substances in three separate clusters, retaining 89% of the total variance. GC/MS analysis of the same materials has permitted us to elucidate in detail the molecular composition and to identify minor components and species that act as markers of the degradation undergone by the materials. The paper also reports the results for the organic residues contained in an Egyptian censer (5th,7th century AD) which was recovered in the excavation of the Necropolis of Antinoe (Egypt), and for the hafting material found on a Palaeolithic tool recovered at the site of Campitello (Arezzo, Tuscany), dating back to the Mid-Pleistocene period. Although DE-MS was found to be a fast analytical tool, it failed to give any information on the presence of less abundant compounds when applied to mixtures of different materials: only mastic resin was found in the residues from the Roman censer, whereas GC/MS analysis identified the presence of a vegetable oil from Brassicaceae seeds and Pinaceae resin. Birch bark pitch as a pure material was identified in the sample from the Palaeolithic flint flake using both procedures. Copyright © 2006 John Wiley & Sons, Ltd. [source] A model to quantify encrustation on ureteric stents, urethral catheters and polymers intended for urological useBJU INTERNATIONAL, Issue 4 2000S.K.S. Choong Objective To validate an encrustation model and to quantify encrustation on currently used urological devices and polymers intended for urological use. Materials and methods An encrustation model was validated: (i) to measure the amount of calcium leaching from the glass model and from the polymer used; (ii) to determine whether the use of a single-source or pooled urine produced similar results; (iii) to determine in vitro encrustation; and (iv) to compare the results of in vivo implantation of the same materials into the bladders of rodents with the in vitro results. A test polymer (a ureteric stent, a urethral catheter or a biomaterial) and a control silicone polymer were housed separately but received human urine from the same reservoir and under the same conditions (pH 6.0 and 37 °C) for 5 days. The amount of calcium encrustation on each polymer was measured using atomic absorption spectroscopy. Each experiment was repeated at least four times and the results expressed as an encrustation index, defined as the ratio of encrustation of the test and reference polymers. Results The amount of calcium leaching from the glass model and polymers tested was insignificant. The use of a single-source or pooled urine gave the same results in the encrustation model. The in vitro results correlated with in vivo implantation of disks into the bladders of rats. Among the commonly used ureteric stents tested, the Cook C-Flex ureteric stents encrusted least. Hydrogel-coated ureteric stents encrusted more than uncoated stents. The Bard polytetrafluoroethylene short-term urethral catheter encrusted more than the Bard hydrogel-coated long-term catheter. A plasma-activated surface modification of a synthetic biomaterial with hyaluronic acid encrusted less than silicone, a long-term biomaterial widely regarded as the ,gold standard'. Conclusion This validated encrustation model is the first to quantify encrustation on currently available ureteric stents and urethral catheters. A novel coating for a biomaterial was identified using the encrustation model, and which encrusted less than silicone. [source] | |||||||||||||||||||||||||||||||