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Selected AbstractsSensitive determination of phenols in environmental water samples with SPE packed with bamboo carbon prior to HPLCJOURNAL OF SEPARATION SCIENCE, JSS, Issue 4 2009Ru-Song Zhao Abstract Bamboo carbon, an inexpensive, readily available material, has attracted great attention in recent years because of adsorptive properties. In this paper, the potential of bamboo carbon as a SPE adsorbent for the determination of phenols, was investigated. Phenols are important environmental contaminants that may adversely affect human health. Parameters influencing extraction efficiency, including type of eluent, eluent volume, amount of adsorbent, as well as sample pH, volume, and flow rate were investigated and optimized. The optimized results exhibited excellent linear relationships between peak area and phenol concentrations over the range of 2.0,100 ng/mL, with precision between 2.2,7.2%. The LODs were 0.06,0.4 ng/mL for the eight phenols tested. The proposed method has been successfully applied to the analysis of several real-world environmental water samples. These results indicate that bamboo carbon may be used as a novel SPE adsorbent for the concentration and determination of phenols in real environmental water samples. [source] Cumulus,Oocyte Communications in the Horse: Role of the Breeding Season and of the Maturation MediumREPRODUCTION IN DOMESTIC ANIMALS, Issue 2 2004S Colleoni Contents Horse is a seasonal breeder and information on oocyte quality outside the breeding season is very limited. Ovaries obtained at the slaughterhouse are a convenient but often limited source of oocytes in this species. As the low quantity of ovaries leads to an intensive use of all available material, it would be useful to know whether ovaries collected during the non-breeding season are suitable for in vitro maturation (IVM). In an attempt to characterize the effect of season on oocyte quality, we investigated the permeability of the gap junctions (GJ) present between cumulus cells and oocytes because of their important role in oocyte growth and maturation. We also compared the effect of supplementing the maturation medium with bovine serum albumin (BSA) or oestrus mare serum (EMS). A total of 645 oocytes isolated from 158 and 154 ovaries collected during the breeding and the non-breeding season, respectively, were used in this study. Oocytes were matured for 30 h in TCM 199 supplemented either with 10% EMS or with 4 mg/ml BSA. The presence of permeable GJs between cumulus cells and oocytes was investigated with the injection of a 3% solution of the fluorescent dye Lucifer yellow into the ooplasm. No differences in efficiency of oocyte retrieval or oocyte meiotic competence were detected between oocytes collected during the breeding and non-breeding season. The vast majority (90%) of the oocytes collected during the breeding season had fully functional communications with their surrounding cumulus cells but such communications were completely interrupted in 55.3% of the oocytes collected during the non-breeding season. During the non-breeding season, the proportion of oocytes whose communications with cumulus cells were classified as closed or intermediate at the end of maturation was lower in the group matured with BSA than with EMS (71.4 vs 97.7, p < 0.05). The same trend, although not statistically significant, was observed during the breeding season also. The presence of BSA caused an incomplete cumulus expansion during both seasons. Our data indicate that oocytes collected during the non-breeding season do not show any meiotic deficiency but lack active communication with the surrounding cumulus cells at the time of their isolation from the ovary. No data are available at present for determining the consequences on the developmental competence even if data from other species suggest that this is likely. [source] Adaptations of an Emergence Trap for Use in Tropical StreamsINTERNATIONAL REVIEW OF HYDROBIOLOGY, Issue 4 2004Hendrik Freitag Abstract An emergence trap based on the MPI Schlitz model was designed for use in the tropics and it was tested over one year in Palawan, the Philippines. Instructions for construction and use are given here. Only commonly available materials were used, except for the collection assembly made of UV-light permeable acrylic glass. Heavy and bulky assemblies were avoided to enable easy transportation in the field. A special modification allows a fast and easy replacement of the screen when damaged by flooding, as is often required when traps are used downstream of headwaters. This type of trap also allows sampling of a wide littoral strip. Problems concerning the use of emergence traps in the humid tropics are discussed based on experience at different longitudinal stream sections in Palawan. The results presented here suggest that this trap should be used especially for qualitative or semi-quantitative approaches. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] A Novel Bis-Thiourea Organocatalyst for the Asymmetric Aza-Henry ReactionADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2008Constantinos Rampalakos Abstract A novel bis-thiourea/2,2,-diaminobinaphthalene (BINAM)-based catalyst for the asymmetric aza-Henry reaction has been developed. This catalyst promotes the reaction of N -Boc imines with nitroalkanes to afford ,-nitroamines with good yields and high enantioselectivities. This catalyst has the advantage that it can be prepared in a single step from commercially available materials. A model is proposed for the catalyst action where both components of the reaction are activated simultaneously by hydrogen bonding. Regardless of the mechanism, the success of the present catalyst demonstrates the potential of bis-thioureas as an interesting class of relatively unexplored catalysts. [source] Balloon sizing and transcatheter closure of acute atrial septal defects guided by magnetic resonance fluoroscopy: Assessment and validation in a large animal model,JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 3 2005Simon Schalla MD Abstract Purpose To quantitatively assess atrial septal defects (ASDs) with small shunts using MRI followed by transcatheter closure monitored by MR fluoroscopy. Materials and Methods Acute ASDs were created in 14 pigs under x-ray fluoroscopy. Six animals were studied in order to select MR-compatible delivery systems and imaging strategies. ASDs in eight animals were examined with balloon sizing under MR fluoroscopy, flow measurements, and contrast media injections, after which transcatheter closure was performed under MR fluoroscopy. The delivery system was assembled from commercially available materials. Results The ratio of pulmonary to systemic flow (Qp/Qs) was reduced from 1.23 ± 0.15 before ASD closure to 1.07 ± 0.11 after ASD closure (P < 0.001). In two out of eight animals Qp/Qs was close to 1.0 before closure despite the presence of defects >15 mm. The ASDs were measurable with MR balloon sizing in all of the animals. Balloon sizing was identical with MR (16.9 ± 2.3 mm) and x-ray fluoroscopy (17.1 ± 1.3 mm). The in-house-assembled delivery system allowed successful placement of closure devices under MR guidance. Conclusion Assessment and closure of small shunts with MR fluoroscopy is feasible. A barrier to the rapid implementation of transcatheter closure in patients is uncertainty about the MR safety of guidewires and device delivery systems. J. Magn. Reson. Imaging 2005;21:204,211. © 2005 Wiley-Liss, Inc. [source] Selective polymerization of functional monomers with Novozym 435JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 24 2007Martijn A. J. Veld Abstract Two novel monomers, ambrettolide epoxide and isopropyl aleuriteate, encompassing functional groups, were obtained in a single step from commercially available materials. Novozym 435 catalyzed ring opening polymerization of ambrettolide epoxide furnished a polymer of Mn = 9.7 kg/mol and PDI = 1.9 while the epoxide groups remained unaffected during the polymerization. Selective polymerization of the primary hydroxyl groups of isopropyl aleuriteate using Novozym 435 was feasible and a polymer with moderate molecular weight (Mn = 5.6 kg/mol, PDI = 3.2) was isolated in moderate yield (43%). Subsequently, copolymerization of isopropyl aleuriteate with ,-CL in different ratios was performed, resulting in soluble, hydroxy functional polymers with good molecular weights (Mn = 10.4,27.2 kg/mol) in good yield (71,78%). The secondary hydroxy groups in the polymer reacted easily with hexyl isocyanate, showing the potential of isopropyl aleuriteate as a comonomer for the synthesis of functional polyesters. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5968,5978, 2007 [source] On the design of ultrafast shutters for time-resolved synchrotron experimentsJOURNAL OF SYNCHROTRON RADIATION, Issue 1 2007Milan Gembicky A comprehensive treatment of the limitations and possibilities for single-pulse selection in synchrotron operating modes with ,150,ns bunch separation, as occurs in the standard operating mode at the Advanced Photon Source, is presented. It is shown that the strength of available materials and allowable kinetic energy build-up limit single-bunch selection for this separation to sample sizes of ,100,µm, and that for minimization of kinetic energy build-up it is preferable to increase the r.p.m. within physically acceptable limits rather than increase the disc radius to obtain a desirable peripheral speed. A slight modification of the equal-bunch spacing standard fill patterns is proposed that allows use of samples as large as 500,µm. The corresponding peripheral speed of the chopper wheel is ,600,m,s,1, which is within the limits of high-strength titanium alloys. For smaller samples, peripheral speeds are proportionally lower. Versatility can be achieved with interchangeable chopper wheels and the use of different orientations of the rotation axis relative to the X-ray beam, which opens the possibility of larger, rather than one-of-a-kind, production runs. [source] The Effect of Protonation on the Optical Properties of Conjugated Fluorene,Pyridine CopolymersMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 20 2008Stefan Kappaun Abstract A series of conjugated alternating and statistical copolymers of fluorene and pyridine are synthesized and characterized. The compounds under investigation, namely poly[2,7-(9,9-dihexylfluorenyl)- alt -(2,6-pyridinyl)] and poly[2,7-(9,9-dihexylfluorenyl)- stat -(2,6-pyridinyl)], are prepared by a Suzuki-type cross-coupling reaction starting from commercially available materials utilizing the recently described catalyst trans -bis(dicyclohexylamine) palladiumdiacetate ("DAPCy"). The target compounds are investigated by nuclear magnetic resonance and infrared spectroscopy, matrix-assisted laser desorption ionization time-of-flight mass spectrometry, thermal analysis, UV,Vis absorption spectroscopy, and luminescence measurements in solution and in the solid state. Special emphasis is placed on studying the consequences of protonation on the photophysical properties of the described materials. Achieving a concise microscopic understanding of the effects of protonation on the absorption and luminescence characteristics is crucial for potential applications in, e.g., optical sensors. To that aim, the results of the systematic studies of the photophysical properties are explained by quantum mechanical calculations. [source] A new austenitic alumina forming alloy: an aluminium-coated FeNi32Cr20MATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 6 2008H. Hattendorf Abstract The FeCrAl alloys owe their low oxidation rate to the formation of a slow growing , -aluminium oxide scale. Therefore they are used, for example, as a substrate material in metal-supported automotive catalytic converters. Increasing exhaust gas temperatures mean that, in addition to the oxidation properties, high temperature mechanical properties should also be improved. Compared to the ferritic FeCrAl alloys, austenitic alloys possess the required high mechanical strength at higher temperatures. However for most commercially available materials the oxidation resistance is not sufficient due to a low aluminium content. High aluminium contents are avoided in austenitic alloys, since they cause severe workability problems, even at aluminium contents, which are below the necessary amount to get a pure alumina scale. The newly developed material Nicrofer 3220 PAl (coated FeNiCrAl) consists of an austenitic FeNi32Cr20 alloy coated with aluminium on both sides. It combines the outstanding oxidation resistance of an alumina forming FeCrAl alloy with the advantage of the high temperature strength of an austenitic alloy. Additionally the oxidation is even lower than the oxidation of the commercial grade Aluchrom YHf (FeCr20Al6),conventional homogenous FeCrAl. Aluminium coated FeNiCrAl can easily be formed into its final shape. Prior to service, an in situ heat treatment is recommended in order to optimize the properties. [source] Percutaneous transtracheal emergency ventilation with a self-made device in an animal modelPEDIATRIC ANESTHESIA, Issue 10 2007RAIK SCHAEFER Summary Background:, Special equipment for emergency percutaneous transtracheal ventilation is often not immediately available. We used a self-made device consisting of a three-way stopcock connected between a G-15 transtracheal airway catheter and an oxygen supply in a simulated 'cannot intubate, cannot ventilate' scenario and tested the hypothesis that the effectiveness of the device depends on the body weight of the experimental animals. Methods:, With approval of the local animal protection committee, two groups of six pigs each with a body weight of 21 ± 2 and 36 ± 6 kg, respectively, were tracheally intubated and mechanically ventilated after induction of anesthesia. Hemodynamic monitoring included cardiac output and arterial, central venous and pulmonary artery pressures. An emergency transtracheal airway catheter was inserted into the trachea and a situation of partial expiratory airway obstruction was created. Each animal was ventilated for 15 min via the transtracheal airway catheter with the self-made device (FiO2 1.0 at an oxygen flow of 15 l·min,1; respiratory rate of 60 min,1; I/E ratio approximately 1 : 1). Results:, Whereas satisfactory oxygenation was achieved in all animals, sufficient ventilation was obtained only in the lightweight animals. Conclusions:, Adequate oxygenation could be provided by jet-like transtracheal ventilation with a simple self-made device using easily available materials. Sufficient ventilation depends on the body weight of the animals. [source] Low-Creep Metallic Thin Films and Reflective Coatings for Optical MicrosystemsPLASMA PROCESSES AND POLYMERS, Issue S1 2007Jan U. Schmidt Abstract The large-scale integration of analog operable MEMS micromirrors onto active CMOS address circuitry involves several challenges. Mirror actuators must be fabricated using CMOS compatible technology, exhibit highly reflecting planar optical surfaces, and stable analog deflection-voltage characteristics not compromised by drift or creep effects. CMOS integration imposes strict limits depending on the range of available materials and the restricted temperature budget. Highly elastic materials such as single-crystalline Si or poly-SiGe have been integrated by layer transfer bonding or PECVD deposition, respectively. In this paper, a novel approach, i.e., the low-temperature monolithic integration of creep-resistant all-sputtered glassy TiAl mirror actuators with Al reflective coating is presented. [source] The $300,000/Year ArchitectARCHITECTURAL DESIGN, Issue 2 2009Urs Gauchet Abstract Could building information modelling (BIM) shake up not only design and delivery processes, but also be set to redefine the construction hierarchy? Could it shift the architect's position from near the bottom of the current food chain to one nearer the top? Urs Gauchat, Professor and Dean of the School of Architecture at the New Jersey Institute of Technology, outlines the architect's place in a complex future where there is an increasing demand for buildings but a demise in available materials and conventional energy sources. Copyright © 2009 John Wiley & Sons, Ltd. [source] Model for Ultrasound-Assisted Lumbar Puncture TrainingACADEMIC EMERGENCY MEDICINE, Issue 2009Melissa Bollinger Lumbar puncture is an important diagnostic procedure in emergency medicine. Data have been published showing improved success rate with ultrasound assistance and the ability of emergency medicine physicians to recognize sonographic lumbar spinous anatomy. However, with educational models and the push for improved patient safety, procedural skills should be practiced on phantoms rather than the "see one, do one, teach one" of the past. There are no currently available phantoms for ultrasound-assisted lumbar puncture training. We have produced a phantom that can be used to train physicians on ultrasound-assisted lumbar puncture with respect to both imaging and procedural competency. A plastic fluid-filled bladder was immersed in gelled opacified mineral oil, a safe and easily used tissue mimic that obscures direct visualization of structures. Spinous anatomy is replicated with the use of wooden struts supporting wooden disks that mimic lumbar spinous processes. The spine analog was mounted over the plastic bladder and surrounded with gelled mineral oil. The phantom produces images similar to human lumbar anatomy. The phantom allows insertion of spinal needles into the "interspinous spaces" with inability to pass the needle outside of those locations. Fluid collection and repeated punctures can be performed on the phantom. Appearance and performance of the phantom were evaluated by physicians with expertise in ultrasound-assisted lumbar puncture. The only limitation is that external appearance is not realistic. This model performs well, is made from readily available materials, and can be used to train physicians in ultrasound-assisted lumbar puncture. [source] | ||||||||||||||||