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Tubes
Kinds of Tubes Terms modified by Tubes Selected AbstractsAXIAL IMPACT STUDIES ON STEEL TUBES AND ZIRCALOY RODEXPERIMENTAL TECHNIQUES, Issue 1 2009R. Rajendran First page of article [source] COMPUTATIONAL FLUID DYNAMICS MODELING OF FLUID FLOW IN HELICAL TUBESJOURNAL OF FOOD PROCESS ENGINEERING, Issue 2 2002T. KORAY PALAZOGLU ABSTRACT The effect of different processing parameters on the degree of mixing and axial and radial pressure drops, during single-phase flow in helical tubes was investigated by using CFD software. Correlations were developed to calculate axial and radial pressure drops, and also the ratio of maximum to average fluid velocities. All of these quantities were found to be dependent on curvature ratio (ratio of tube diameter to coil diameter). Flow visualization experiments were performed to assess the degree of mixing in different configurations. At identical conditions, the degree of mixing was higher in the system with the large curvature ratio, which is in agreement with the simulation results. A minimum ratio of maximum to average fluid velocities of 1.61 was achieved, representing a 20% reduction in hold tube length for Newtonian fluid in laminar flow. [source] Unrecognized Misplacement of Endotracheal Tubes in a Mixed Urban to Rural Emergency Medical Services SettingACADEMIC EMERGENCY MEDICINE, Issue 9 2003Michael E. Jemmett MD Abstract Objective: To determine the rate of unrecognized endotracheal tube misplacement when performed by emergency medical services (EMS) personnel in a mixed urban and rural setting. Methods: The authors conducted a prospective, observational analysis of out-of-hospital endotracheal intubations (EIs) performed by EMS personnel serving a mixed urban, suburban, and rural population. From July 1, 1998, to August 30, 1999, emergency physicians assessed and recorded the position of out-of-hospital EIs using auscultation, direct laryngoscopy, infrared CO 2 detectors, esophageal detector devices, and chest x-ray. The state EMS database also was reviewed to determine the number of EIs involving patients transported to the authors' medical center and paramedic assessment of success for these encounters. Results: A total of 167 out-of-hospital EIs were recorded, of which 136 (81%) were deemed successful by EMS personnel. Observational forms were completed for 109 of the 136 patients who arrived intubated to the emergency department. Of the studied patients, 12% (13 of 109) were found to have misplaced endotracheal tubes. For the patients with unrecognized improperly placed tubes, 9% (10 of 109) were in the esophagus, 2% (2 of 109) were in the right main stem, and 1% (1 of 109) were above the cords. Paramedics serving urban and suburban areas did not perform significantly better (p < 0.05) than intermediate-level providers serving areas that are more rural. Conclusions: The incidence of unrecognized misplacement of endotracheal tubes by EMS personnel may be higher than most previous studies, making regular EMS evaluation and the out-of-hospital use of devices to confirm placement imperative. The authors were unable to show a difference in misplacement rates based on provider experience or level of training. [source] Amiodarone Attenuates Fluoride-induced Hyperkalemia in VitroACADEMIC EMERGENCY MEDICINE, Issue 2 2003Mark Su MD Abstract Poisoning by hydrofluoric acid or fluoride salts results in hypocalcemia, hypomagnesemia, and hyperkalemia with subsequent cardiac dysrhythmias. In previous studies, quinidine attenuated fluoride-induced hyperkalemia in vitro, and enhanced survival in animals. Like quinidine, amiodarone is a potassium channel blocker, although amiodarone is more familiar to clinicians due to its recent inclusion in advanced cardiac life support (ACLS) protocols. Objectives: This in-vitro study of human erythrocytes was designed to determine whether amiodarone could attenuate fluoride-induced hyperkalemia. Methods: Six healthy volunteers each donated 60 mL of blood on three occasions. Each specimen was divided into 12 tubes, incubated at 37°C, and oxygenated with room air. An aqueous sodium fluoride (F,) solution was added to tubes 1,9. Incremental amounts of quinidine were added to tubes 1,4 (Q1,Q4) to attain calculated concentrations of 0.73 ,g/mL, 1.45 ,g/mL, 2.9 ,g/mL, and 5.8 ,g/mL, respectively. Incremental amounts of amiodarone were added to tubes 5,8 (A1,A4) to attain calculated concentrations of 0.38 ,g/mL, 0.75 ,g/mL, 1.5 ,g/mL, and 3.0 ,g/mL, respectively. Tubes 9,12 were controls for each of F,, amiodarone, quinidine alone, and no additive, respectively. Extracellular potassium concentration ([K+]) was followed, and an objective endpoint was defined as the rise in potassium concentration at 6 hours. Results: Fluoride produced a significant change in [K+] by 6 hours in all samples. Quinidine produced a J-shaped curve in its ability to attenuate the rise in [K+], with only one concentration, Q3, demonstrating significance versus tube 9 (control). Amiodarone also demonstrated a J-shaped dose,response effect, with statistical significance at A1, A2, and A3 versus tube 9 (control). There was no significant difference among the effective concentrations (Q3, A1, A2, and A3) of both drugs. Conclusions: In this in-vitro model using human blood, amiodarone and quinidine both attenuated F, -induced hyperkalemia. Further study is indicated to determine whether amiodarone enhances survival in F, -poisoned animals. [source] Numerical Modelling of Flow Boiling Heat Transfer in Horizontal Metal-Foam Tubes,ADVANCED ENGINEERING MATERIALS, Issue 10 2009Wei Lu Abstract The flow boiling heat transfer performance in horizontal metal-foam tubes is numerically investigated based on the flow pattern map retrieved from experimental investigations. The flow pattern and velocity profile are generally governed by vapour quality and mass flow rate of the fluid. The porous media non-equilibrium heat transfer model is employed for modelling both vapour and liquid phase zones. The modelling predictions have been compared with experimental results. The effects of metal-foam morphological parameters, heat flux and mass flux on heat transfer have been examined. The numerical predictions show that the overall heat transfer coefficient of the metal-foam filled tube increases with the relative density (1-porosity), pore density (ppi), mass and heat flux. [source] Concentric Sub-micrometer-Sized Cables Composed of Ni Nanowires and Sub-micrometer-Sized Fullerene Tubes,ADVANCED FUNCTIONAL MATERIALS, Issue 7 2007F. Tao Abstract Highly ordered arrays of submicrometer-sized coaxial cables composed of submicrometer-sized C60 and C70 tubes filled with Ni nanowires are successfully prepared by combining a sol,gel method with an electrodeposition process. The wall thickness of the submicrometer-sized tubes can be adjusted by the concentration of fullerenes and the immersion time. The thermal stability of the submicrometer-sized C60 tubes is studied by Raman spectroscopy and it is found that these structures can be easily decomposed to form carbon nanotubes at relatively low temperatures (above 573,K) in an alumina template. These novel coaxial cable structures have been characterized by transmission electron microscopy (TEM), high-resolution TEM (HRTEM), scanning electron microscopy (SEM), field-emission SEM (FESEM), Raman spectroscopy, elemental mapping, energy dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD), vibrating sample magnetometer (VSM) experiments, and superconducting quantum interference device (SQUID) measurements. Magnetic measurements show that these submicrometer-sized cables exhibit enhanced ferromagnetic behavior as compared to bulk nickel. Moreover, submicrometer-sized C70/Ni cables show uniaxial magnetic anisotropy with the easy magnetic axis being parallel to the long axis of the Ni nanowires. C70/Ni cables also exhibit a new magnetic transition at ca.,10,K in the magnetization,temperature (M,T) curve, which is not observed for the analogous C60/Ni structures. The origin of this transition is not yet clear, but might be related to interactions between the Ni nanowires and C70 molecules. There is no preferred magnetization axis in submicrometer-sized C60/Ni cables, which implies that the Ni nanocrystals have different packing modes in the two composites. These different crystalline packing modes lead to different magnetic anisotropy in the two composites, although the Ni nanocrystals have the same face-centered cubic (fcc) structure in both cases. [source] Submicrometer-Sized Vaterite Tubes Formed Through Nanobubble-Templated Crystal Growth,ADVANCED MATERIALS, Issue 19 2005W. Fan Electrolytic deposition is used to prepare submicrometer-sized vaterite (CaCO3) tubes (see Figure) in the absence of organic molecules, the presence of which was previously thought to be necessary for the growth of calcium carbonate crystals in complex morphologies. The mechanism of formation is shown experimentally to be hydrogen-nanobubble-templated crystal growth. [source] Frass sampling and baiting indicate European earwig (Forficula auricularia) foraging in orchardsJOURNAL OF APPLIED ENTOMOLOGY, Issue 5 2006D. M. Suckling Abstract:, Earwigs are significant generalist predators of a range of orchard pests, but quantitative assessment of earwig density and beneficial impact is difficult. A sampling system was designed and tested, based on field placement of polycarbonate tubes in apple trees as scotophase arboreal refugia. Tubes containing artificial diet and provided with a black plastic sleeve had the highest earwig counts. Tubes with diet or the black sleeve alone were less preferred. Presence of distinctive frass was also evident in polycarbonate tubes containing artificial diet, and earwig frass was recorded at a higher frequency than earwig presence, indicating foraging and detection of the tubes at a higher rate than their use as shelters. At the tree level, there was a weak correlation between frass abundance and predation rates on leafroller egg batches placed as baits in the canopy, but not with earwig density measured by corrugated cardboard rolls or diet tubes. Diet tubes have the potential to offer new insights into earwig foraging behaviour in orchards. [source] Centrifugal Casting of Thin-Walled Ceramic Tubes from Preceramic PolymersJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 7 2003Reinhold Melcher Thin-walled (wall thickness, 100,2000 ,m) mono- and bilayered ceramic tubes in the system Si,O,C,(N) were obtained by centrifugal casting of a polysiloxane/filler suspension. Si and SiC powders were dispersed in polyorganosiloxane/triethoxysilane solutions. After centrifugal casting in a Teflon tube with a rotational speed of 2000 rpm and subsequent cross-linking at 130°C and 60 rpm, the tubes were pyrolyzed in argon or in nitrogen at 1400,1600°C. Bilayered tubes with controlled variation of porosity were obtained by overcasting the monolayer green tubes with a modified slurry composition. [source] Structure of Polymer Brushes in Cylindrical Tubes: A Molecular Dynamics SimulationMACROMOLECULAR THEORY AND SIMULATIONS, Issue 7 2006Dimitar I. Dimitrov Abstract Summary: Molecular dynamics simulations of a coarse-grained bead-spring model of flexible macromolecules tethered with one end to the surface of a cylindrical pore are presented. Chain length N and grafting density , are varied over a wide range and the crossover from "mushroom" to "brush" behavior is studied for three pore diameters. The monomer density profile and the distribution of the free chain ends are computed and compared to the corresponding model of polymer brushes at flat substrates. It is found that there exists a regime of N and , for large enough pore diameter where the brush height in the pore exceeds the brush height on the flat substrate, while for large enough N and , (and small enough pore diameters) the opposite behavior occurs, i.e. the brush is compressed by confinement. These findings are used to discuss the corresponding theories on polymer brushes at concave substrates. Snapshot picture of a brush grafted inside of a cylinder, for , , displaying different chains in distinct colors in order to be able to distinguish them. Top shows a side view of the cylinder, and the lower part a view of the cross-section. Note that the particles forming the cylindrical wall are not displayed. [source] Gene expression measurements in the context of epidemiological studiesALLERGY, Issue 12 2008C. Bieli Background:, Gene expression measurements became an attractive tool to assess biological responses in epidemiological studies. However, collection of blood samples poses various technical problems. We used gene expression data from two epidemiological studies to evaluate differences between sampling methods, comparability of two methods for measuring RNA levels and stability of RNA samples over time. Methods:, For the PARSIFAL study, PBLC of 1155 children were collected using EDTA tubes in two countries. In the PASTURE study, tubes containing RNA-stabilizing solutions (PAXgene® Blood RNA Tubes; PreAnalytiX) were used to collect cord blood leucocytes of 982 children in five countries. Real-time PCR (conventional single tube assay and high-throughput low density arrays) was used to quantify expression of various innate immunity genes. In 77 PARSIFAL samples, gene expression was measured repeatedly during prolonged storage. Results:, In PARSIFAL (EDTA tubes) the median RNA yield after extraction significantly differed between the two centres (70 and 34 ng/,l). Collecting blood into an RNA-stabilizing solution markedly reduced differences in RNA yield in PASTURE (range of medians 91,107 ng/,l). The agreement [Spearman rank correlation (r)] between repeated measurements of gene expression decreased with increasing storage time [e.g., for CD14: r (first/second measurement) = 0.35; r (first/third measurement) = 0.03]. RNA levels measured with either the conventional method or low-density arrays were comparable (r > 0.9). Conclusion:, Collecting blood samples into tubes containing an RNA-stabilizing solution increases RNA yield and reduces its variability. Long-term storage of samples may lead to RNA degradation, requiring special attention in longitudinal studies. [source] Development of CdSSe/CdS VCSELs for Application to Laser Cathode Ray TubesPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 4 2004K. P. O'Donnell Abstract This report summarises recent progress towards the realisation of Laser Cathode Ray Tube (LCRT) devices on the basis of II,VI semiconductors. Although such devices were demonstrated over 30 years ago, using bulk crystalline materials as the active media, practical lasers that operate at room temperature for extended periods of time are not yet readily available. We aim to overcome this roadblock by reducing the threshold power densities of working lasers. By embedding heterostructures, grown using metalorganic vapour phase epitaxy (MOVPE), within all-dielectric microcavities, the necessary threshold reductions can be made. The construction and testing of an exemplar device, based upon CdSSe/CdS (hex) multiple quantum wells, is described. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Raman spectroelectrochemistry of index-identified metallic carbon nanotubes: The resonance rule revisitedPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 13 2006Ladislav Kavan Abstract Raman spectroelectrochemistry of HiPco single-walled carbon nanotubes was studied at conditions, when the radial breathing modes can be assigned to defined tubes or to families of tubes. The particular tubes exhibit a varying sensitivity to electrochemical doping, monitored as an attenuation of the RBM intensities. Tubes in optimum resonance with the exciting laser show the strongest doping-induced drop of the RBM intensity while those out of resonance have only a week response to doping. Our "resonance rule" is particularly important for metallic tubes, which cannot be indexed similarly to semiconducting tubes using photoluminescence data. This paper is focused on metallic tubes, which are resonance enhanced through the E11M optical transition. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Nitrogen Atmospheric Pressure Post Discharges for Surface Biological Decontamination inside Small Diameter TubesPLASMA PROCESSES AND POLYMERS, Issue 6 2008Anne-Marie Pointu Abstract A nitrogen afterglow at atmospheric pressure has recently been described as able to transport active species over long distances in small diameter tubes, with a biocidal effect. For a discharge gas composed of nitrogen, either of high purity or with some controlled ppm of oxygen, survival curves are presented. The afterglow, flowing at 40 slm in a cylindrical quartz tube with 8 mm internal diameter is studied using emission spectroscopy. Fundamental or excited states of atomic or molecular species of parent gases are detected and evaluated. Their absolute concentration is measured along the tube axis. Correlated to transport equations, results give information on the creation and destruction reactions of these species, especially of the O(1S) metastable state of O, the species that has been shown to boost the biocidal effect. [source] Role of Albumin Coating of Tympanostomy Tubes: Long-Term Clinical EvaluationTHE LARYNGOSCOPE, Issue 12 2007Teemu J. Kinnari MD Abstract Objective: Our previous work has shown that albumin coating of tympanostomy tubes prevented adhesion of proteins or bacteria on the tube surface in vitro and in a 9-month prospective follow-up study. This study was continued until all tubes were extruded. Study Design: A prospective, clinical trial. Methods: The randomized, double-blind clinical trial had 149 patients. The randomization was revealed after the follow-up period of 9 months. The number of tube sequelae in ears with human serum albumin (HSA)-coated titanium tympanostomy tubes was compared with the contralateral ears with uncoated, otherwise identical titanium tubes. The follow-up continued until all tubes were extruded, followed by evaluation of each tympanostomized patient. Results: No significant difference between the two tube types emerged after the 9-month follow-up. Among the patients younger than 2 years, one of the three typical bacteria causing acute otitis media (AOM), Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis, was found in 45% of all bacterial cultures taken during AOM. However, among patients older than 2, one of these bacteria appeared in 17% of all the bacterial cultures and in 8% of cultures taken during the summer. Conclusions: After the first 9 follow-up months, no difference was found in the sequelae related to uncoated and HSA-coated tubes. The typical bacteria causing AOM were found less frequently among patients older than 2 years. A profile of tympanostomy patients in Finland will be given. [source] Albumin-Coated Tympanostomy Tubes: Prospective, Double-Blind Clinical Study,THE LARYNGOSCOPE, Issue 11 2004Teemu J. Kinnari MD Abstract Objectives: Coating an implant with albumin prevents adhesion of proteins, bacteria, and platelets and thus may lead to its improved and prolonged function. Previously, we have demonstrated the inhibition of binding of fibronectin, one of the most adhesive glycoproteins, on human serum albumin (HSA)-coated tympanostomy tubes and the durability of this binding inhibition in a 8-month trial. We have also demonstrated that the HSA coating inhibits the binding of Staphylococcus aureus and Pseudomonas aeruginosa to titanium plates. This prospective study evaluated the effect of albumin coating on tympanostomy tube sequelae and on the outcome of tympanostomized patients. Study Design: Double-blind, prospective, randomized clinical trial. Methods: Two otolaryngological centers in southern Finland enrolled 179 pediatric patients. Number of tube occlusions and otorrhea and tube ventilation time in the ears with HSA-coated titanium tympanostomy tubes were compared with the contralateral ear with its uncoated, otherwise identical titanium tube during a 9-month follow-up period. Results: In HSA-coated tubes, average ventilation time was slightly longer and the number of early tube occlusions significantly less (P < .05). Moreover, in patients with perioperative bleeding, the coating prolonged average ventilation time of tympanostomy tubes significantly (P < .05). Conclusions: HSA coating reduces early tube occlusions by preventing adherence of blood and secretion. [source] No Effect of a Nasal Decongestant on Eustachian Tube Function in Children With Ventilation Tubes,THE LARYNGOSCOPE, Issue 6 2002Niels van Heerbeek MD Abstract Objective The aim of the study was to assess the effect of a topical decongestant on eustachian tube function in children with ventilation tubes because of persistent otitis media with effusion. Study Design A randomized, double-blinded, placebo-controlled study. Methods At the outpatient departments of a secondary referral hospital and a tertiary referral hospital, eustachian tube function was measured before and after intranasal administration of five drops of 0.05% xylometazoline hydrochloride or placebo in 80 randomly selected children with ventilation tubes because of otitis media with effusion. Results Xylometazoline nose drops had no effect on the ventilatory or the protective function of the eustachian tube. Conclusions Topical decongestants do not have a positive effect on eustachian tube function in children. Therefore, the use of topical decongestants to prevent or treat otitis media with effusion in children is not justified and should be discouraged. [source] Self-Assembly of Rodlike Bio-nanoparticles in Capillary Tubes,ANGEWANDTE CHEMIE, Issue 5 2010Yuan Lin Dr. Richtungsweisend: Unterschiedliche Muster resultieren beim Trocknen einer Lösung von Tabakmosaikvirus(TMV)-Partikeln in einer Glaskapillare (siehe AFM-Bilder). Die Eigenschaften der hierarchischen Struktur können über die Partikelkonzentration, den Trocknungsprozess und die Beschaffenheit der Röhrchenwand gesteuert werden. Die inwändig gemusterten Röhren wurden genutzt, um glatte Muskelzellen aus der Mausaorta auszurichten. [source] Use of a single silastic chest drain following thoracotomy: initial evaluationANZ JOURNAL OF SURGERY, Issue 8 2005Nand K. Kejriwal Background: It is standard practice to use multiple large bore semi-rigid chest tubes to drain the pleural cavity following thoracic procedures. These can cause pain and discomfort at the insertion site. Methods: We describe our experience with the use of a single small silastic drain following thoracotomy. From November 2001 to November 2003, size19-F silastic chest tubes (Blake drains) were used for drainage of the pleural cavity in 37 patients at our institution. The patients ranged in age from 18 to 81 years (mean 65). The operations included 22 lobectomies, two bilobectomies, 10 wedge resections, and three other procedures. Results: Total drainage in each patient ranged from 420 to 5440 mL (mean 1387 mL). Tubes were left in place for an average of 4.3 days (range 1,12). The average postoperative length of stay was 7.6 days (range 3,44, median 5). Three patients required insertion of an additional tube for dislodgement, persistent air leak, and bronchopleural fistula, respectively. These complications occurred among the first 15 patients in the present series. None of the patients had persistent pleural effusion. Subjectively, these tubes were more comfortable for the patients and were easier to remove. Summary: The use of a single, small silastic chest drains following thoracotomy may be safe and effective in draining both fluid and air, though an additional tube may be necessary for persistent leaks. [source] Error analysis of proper motions in decination obtained for 807 Hipparcos stars from PZT observations over many decadesASTRONOMISCHE NACHRICHTEN, Issue 8 2010G. Damljanovi Abstract After publication of the Hipparcos catalogue (in 1997), a few new astrometric catalogues have appeared (TYCHO-2, ARIHIP, etc.), as a good combination of the Hipparcos satellite and ground-based data, to get more accurate coordinates and proper motions of stars than the Hipparcos catalogue ones. There are also investigations on improving the Hipparcos coordinates and proper motions by using the astrometric observations of latitude and universal time variations (via observed stars referred to Hipparcos catalogue), together with Hipparcos data, carried out during the last few years. These kind of ground-based data were collected at the end of the last century by J. Vondrák. There are about 4.4 million optical observations made worldwide at 33 observatories and with 47 instruments during 1899.7,1992.0; our Belgrade visual zenith telescope data (for the period 1949.0-1986.0) were included. First of all, these data were used to determine the Earth Orientation Parameters , EOP, but they are also useful for the opposite task , to check the accuracy of coordinates and proper motions of Hipparcos stars which were observed from the ground over many decades. Here, we use the latitude part of ten Photographic Zenith Tubes , PZT data (more than 0.9 million observations made at 6 observatories during the time interval 1915.8,1992.0), and combine them with the Hipparcos catalogue ones, with suitable weights, in order to check the proper motions in declination for 807 common PZT/Hipparcos stars (and to construct the PZT catalogue of ,, for 807 stars). Our standard errors in proper motions in declination of these stars are less than or equal to the Hipparcos ones for 423 stars. The mean value of standard errors of 313 stars observed over more than 20 years by PZT is 0.40 mas/yr. This is 53% of 0.75 mas/yr (the suitable value from the Hipparcos catalogue). We used the Least Squares Method , LSM with the linear model. Our results are in good agreement with the Earth Orientation Catalogue , EOC-2 and the new Hipparcos ones. The main steps of the method and the investigations of systematic errors in determined proper motions (the proper motion differences with respect to the Hipparcos values, the EOC-2 ones and the new Hipparcos ones, as a function of ,, ,, and magnitude) are presented here. A comparison of the four catalogues by pairs shows that there is no significant relationship between the differences of their ,, values and magnitudes and color indices of the common 807 stars. All catalogues have relatively small random and systematic errors which are close to each other. However, the comparison shows that our formal errors are too small. They are underestimated by a factor of nearly 1.7 (for EOC-2, it is 2.0) if we take the new Hipparcos (or Hipparcos) data as reference (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Fabrication of Artificial Endothelialized Tubes with Predetermined Three-Dimensional Configuration from Flexible Cell-Enclosing Alginate FibersBIOTECHNOLOGY PROGRESS, Issue 1 2007Takayuki Takei One possible strategy for creating three-dimensional (3D) tissue-engineered organs in vitro is to develop a vasculature for sufficient transport of oxygen and nutrients within these constructs. Here, we describe a novel technique to fabricate endothelialized tubes with predetermined 3D configuration, as a starting point for self-developing capillary-like networks in vitro. Calcium-alginate hydrogel fibers of ca. 250 and 500 ,m in diameter, enclosing bovine carotid artery vascular endothelial cells (BECs), were used as templates for endothelialized tubes. Fibers were prepared by extruding a 2% (w/v) sodium alginate solution containing BECs into a 100 mM calcium chloride solution flowing in the same direction. Fibers were embedded in type I collagen gels and enzymatically degraded by alginate lyase, resulting in channels with predetermined 3D configuration filled with a BEC suspension. Cells attached to and covered the surfaces of the channels. Exposing the cells to medium containing basic fibroblast growth factor resulted in their migration into the ambient collagen gel and self-assembly into capillary-like structures. These results demonstrate that using artificial endothelialized tubes with predetermined 3D configuration, as a starting point for a self-developing capillary-like network, could be potentially useful for constructing 3D tissue-engineered organs. [source] Flow Structures of a Liquid Film Falling on Horizontal TubesCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 6 2005J. Mitrovic Abstract Patterns of a liquid film falling across a vertical array of horizontal tubes change from droplet mode at low flow rates to liquid sheet at high flow rates. Between these limits, liquid columns form as a further stable flow pattern. The transition from one flow mode to another occurs via unstable structures consisting simultaneously of droplets and columns or of merging columns. The boundaries of the flow modes can be obtained from relationships expressing the flow rate as a function of physical properties, that is, the Reynolds number as a function of the Kapitza number. Correlations for the pattern boundaries recommended in the literature are compared with each other and found to be in acceptable agreement for practical purposes. [source] Effectiveness of canalicular laceration repair using monocanalicular intubation with Monoka tubesACTA OPHTHALMOLOGICA, Issue 7 2009Hwa Lee Abstract. Purpose:, This study aimed to evaluate the clinical efficacy of canalicular laceration repair using monocanalicular intubation with Monoka tubes. Methods:, A total of 36 single lacerated canaliculi were repaired using monocanalicular intubation with Monoka tubes, without mucosal anastomosis of the canaliculi, and were retrospectively reviewed. Demographic information, injury locations, associated ocular injuries, complications and outcomes were analysed. Results:, Mean patient age was 34 years (range 1,64 years). Tubes were removed at a mean of 4.2 months (range 3,6 months). There were 26 lower canalicular lacerations (72%) and 10 upper canalicular lacerations (28%). Overall, 34 of 36 cases (92%) showed improvement in symptoms and exhibited positivity on the dye disappearance test at 4,12 months after the procedure (mean 7.8 months). In total, 21 patients (58%) achieved complete success, 13 patients (36%) achieved partial success and two patients (6%) suffered surgical failure. Complications were seen in five cases and included two early tube protrusions, two punctal slits and one punctal granuloma. Conclusions:, Monocanalicular intubation with Monoka tubes leads to successful outcomes without significant complications and offers an alternative to bicanalicular intubation in the treatment of monocanalicular lacerations. [source] Recent developments of glaucoma in childrenACTA OPHTHALMOLOGICA, Issue 2009KK NISCHAL Pediatric glaucoma can be a very challenging area of practice. There have been four areas of advances in the last 5-10 years to help improve the outcomes of treatment. Improved pharmacological agents available have been developed for adult glaucoma some of which have been safely used in children , the exception being brimonidine. A better understanding of the dynamics of aqueous flow and how to harness this have led to a safer filtration methodology with the use of antimetabolites especially Mitomycin C. Tubes or setons have been improved in terms of design with valved tubes eg the Ahmed tube , becoming more popular. Lastly, high frequency ultrasound has led to a better understanding and also better delievery of cyclodiode laser ab externo. Endophotocycloablation has also offered increased efficacy of cyloablation. [source] ChemInform Abstract: Lone-Pair Self-Containment in Tellurite Tubes: Hydrothermal Syntheses and Structures of BaTe3O7 and BaTe4O9.CHEMINFORM, Issue 28 2002Magnus G. Johnston Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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] New Generation of Gold Catalysts: Nanoporous Foams and Tubes,Is Unsupported Gold Catalytically Active?CHEMPHYSCHEM, Issue 13 2007Masatake Haruta Prof. Dr. Gold fever: Gold turns out to be catalytically very active, provided that either one or two of the three conditions shown in the graphic are fulfilled. In CO oxidation at room temperature even unsupported gold is active in the presence of alkaline water. The active states of gold in the gold catalysts reported so far can be classified into four groups: bulk gold, nanoparticles, clusters or thin layers with specific sizes, and cations. [source] Feasibility of commercial interferon-,-based methods for the diagnosis of latent Mycobacterium tuberculosis infection in Finland, a country of low incidence and high bacille Calmette,Guérin vaccination coverageCLINICAL MICROBIOLOGY AND INFECTION, Issue 8 2007T. Tuuminen Abstract The performances of the QuantiFERON-TB Gold in Tubes (QFGT), T SPOT-TB (ELISPOT) and the Mantoux test were compared for the diagnosis of latent tuberculosis infection in Finland, a country of low tuberculosis incidence. In Cohort A (16 students), freshly isolated peripheral blood mononuclear cells (PBMCs), and in Cohort B (21 school children), cryopreserved PBMCs, were used for the ELISPOT assay. Cryopreservation of cells in fetal calf serum, but not in serum-free medium, produced false-positive results. Discrepancies between the results of the assays were observed. It was concluded that the accuracy of these ex-vivo methods needs additional evaluation. [source] Morphology studies of doped polyaniline micro/nanocomposites containing TiO2 nanoparticles and Fe3O4 microparticlesPOLYMER COMPOSITES, Issue 7 2009Sook-Wai Phang To produce polyaniline (PAni) nanodevices that display excellent microwave absorbing behaviors, novel hexanoic acid-doped PAni micro/nanocomposites containing TiO2 nanoparticles and Fe3O4 microparticles (PAni/HA/TiO2/Fe3O4) were prepared by template-free method, particularly to improve the dielectric and magnetic property of PAni. PAni/HA/TiO2/Fe3O4 synthesized at different polymerization temperatures and polymerization time by various TiO2 and Fe3O4 contents, and particles size of TiO2 were prepared. The aim of this research is to investigate the effect of synthesis condition on the morphology behaviors of nanorods/tubes. The resulted nanorods/tubes indicated that PAni micro/nanocomposites exhibited polymerization through elongation. PAni micro/nanocomposites synthesized at 0°C resulted in large amounts of nanorods/tubes compared with those synthesized at subzero temperature and above 0°C. PAni/HA/TiO2 and PAni/HA/TiO2/Fe3O4 synthesized using TiO2 with diameter (particles size) 180 nm resulted in large amounts of nanorods/tubes (diameter nanorods/tubes = 80,140 nm) compared with those synthesized using TiO2 with diameter of 30 and 6 nm. Increasing TiO2 and Fe3O4 content above 10% will significantly reduce the amount of nanorods/tubes. In conclusion, synthesis parameters mentioned above are the significant factors that might affect the morphology behaviors of PAni nanostructures. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers [source] Stylet Bend Angles and Tracheal Tube Passage Using a Straight-to-cuff ShapeACADEMIC EMERGENCY MEDICINE, Issue 12 2006Richard M. Levitan MD Abstract Objectives Malleable stylets improve maneuverability and control during tube insertion, but after passage through the vocal cords the stiffened tracheal tube may impinge on the tracheal rings, preventing passage. The goal of this study was to assess insertion difficulty with styletted tubes of different bend angles. Methods Tube passage was assessed with four different bend angles (25°, 35°, 45°, and 60°) using straight-to-cuff,shaped tubes. In two separate airway procedure classes, 16 operators in each class (32 total) placed randomly ordered styletted tubes of the different angles into eight cadavers (16 total). Operators subjectively graded the ease of tube passage as no resistance, some resistance, or impossible to advance. Results No resistance was reported in 69.1% (177/256) at 25°, in 63.7% (163/256) at 35°, in 39.4% (101/256) at 45°, and in 8.9% (22/256) at 60°. Tube passage was impossible in 2.3% of insertions (6/256) at 25°, in 3.5% (9/256) at 35°, in 11.3% (29/256) at 45°, and in 53.9% (138/256) at 60°. The odds ratios of impossible tube passage for 35°, 45°, and 60° vs. 25° were 1.52 (95% confidence interval [CI] = 0.55 to 4.16), 5.32 (95% CI = 2.22 to 12.71), and 48.72 (95% CI = 21.35 to 111.03), respectively. Conclusions Bend angles beyond 35° with straight-to-cuff styletted tracheal tubes increase the risk of difficult and impossible tube passage into the trachea. The authors did not compare different stylet stopping points, stylets of different stiffness, or tracheal tubes with different tip designs, all variables that can affect tube passage. [source] Morphological and immunohistochemical studies on cleft palates induced by 2,3,7,8-tetrachlorodibenzo- p -dioxin in miceCONGENITAL ANOMALIES, Issue 2 2008Kumiko Fujiwara ABSTRACT Morphological and immunohistological examinations were performed to reveal the mechanisms of cleft palate induction by 2,3,7,8-tetrachlorodibenzo- p -dioxin (TCDD). ICR strain mice 8,10 weeks of age were used in the study. TCDD was administered in olive oil on gestation day (GD) 12.5 with gastric tubes at 40 ,g/kg. From GD 13.5 to 16.5, palates were examined by scanning electron microscopy (SEM), hematoxyline,eosin (HE) staining, and immunohistochemical staining of FGFR1/2, TGF-,3, MSX1 and LHX8. In the control group, both of the palatal shelves began elevating on GD 14.0 and finished within 6 h. After the elevation, all of the shelves had completely fused with each other on GD 14.5. In the TCDD-treated group, palatal shelves elevated 1 day later than in the control group. However, all palates had elevated by GD 15.0. After the elevation, the shelves contacted each other and fused; however, they were separated on GD16.0. HE staining showed that medial edge epithelium (MEE) was thinner in the TCDD group than in the control group. MEE observed under a high magnification (×2500) exhibited filopodia-like filaments and the cells were bulged in the control group. In contrast, in the TCDD group, no filaments were observed and the cells were flat with unclear boundaries. Immunohistologically, there were no characteristic findings except for FGFR1. FGFR1 was not expressed in the TCDD group after the fusion phase (GD 14.5). TCDD induces many morphological and molecular changes to MEE cells and causes cleft palates. [source] | ||||||||||||||||||||||||||||||||||||||||||||||