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Selected AbstractsTotal nucleated cell differential for blood and bone marrow using a single tube in a five-color flow cytometer,,CYTOMETRY, Issue 2 2008Sven Björnsson Abstract Background: Flow cytometry allows the use of several antibodies in addition to light scatter, and most flow cytometers will provide at least seven measurements on each cell passing through the laser beam. A skilled microscopist will classify at least 14 cell classes in bone marrow or blood. Our goal was to use the seven parameters available in our flow cytometer to provide a reliable differential count using only one tube. Methods: Peripheral blood samples were analyzed on the Beckman Coulter LH750 cell counter, and the flagging and messages from the cell counter were used to select normal or pathological samples. Samples without flags (N = 50), with >2% erythroblasts (N = 80), or with "Blast" or "Verify diff" flags (N = 54) were investigated. We used a lyse-no-wash method to ensure minimal loss of fragile cells with live gating on DRAQ5-positive cells to acquire only nucleated cells. The FL-1 to FL-4 channels were used for the antibodies CD36-FITC, CD203-PE, CD138-PE, CD45-ECD, CD16-Pcy5, and CD56-Pcy5. FL-5 was used for the DNA-stain DRAQ5. Results: Using live gate acquisition on DRAQ5, we were able to classify total nucleated cells into 10 classes. We were unable to identify megakaryocytes, but platelets could be studied by rerunning the sample after dilution and gating on DRAQ5-negative CD36-posive events. Validation against digitized microscopy and cell counter showed linear correlations within each cell class with correlation coefficients that seem reasonable for cellular classification. The lowest correlation was found for basophil granulocytes. Flow cytometry detected twice as many immature neutrophils compared to microscopy. Conclusions: We have designed a one-tube immunophenotyping panel for classification of total nucleated cells and platelets in blood or bone marrow. The seven parameters available in one single tube in our cytometer seem to be enough for reliable differential count even in difficult pathological samples. The analytical imprecision of the flow cytometer differential was much lower than that obtained with microscopy or cell counter differentials. © 2007 Clinical Cytometry Society. [source] Synthesis and characterization of metal sulfide clusters for toxicological studiesENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2002Karl C. Bowles Abstract Zinc sulfide clusters were synthesized and characterized at low micromolar concentrations to assess the effect of metal-sulfide ligands on metal toxicity to aquatic organisms in oxic environments. Recommended preparation times are greater than 2 h initial reaction of equimolar sodium sulfide and zinc nitrate, followed by oxic aeration for 3 d. Ionic strength, pH, and anoxic stabilization time were found to be relatively unimportant in controlling the final yield. Adsorptive losses of zinc sulfide (ZnS) clusters to surfaces, however, were significant for a variety of vessel materials and membrane filters. Ionic strength and pH were found to be important factors controlling the extent of adsorptive losses with minimal loss for pHs greater than 9 and for soft waters. The Ag(I), Cu(II), and Hg(II) as metal sulfides completely suppress the analysis of sulfide, whereas Pb(II), Mn(II), and Co(II) partially suppress the analysis of sulfide by the methylene blue technique. Ultraviolet and fluorescence spectra are shown for synthesized ZnS clusters. [source] Papillary and muscle invasive bladder tumors with distinct genomic stability profiles have different DNA repair fidelity and KU DNA-binding activitiesGENES, CHROMOSOMES AND CANCER, Issue 4 2009Johanne Bentley Low-grade noninvasive papillary bladder tumors are genetically stable whereas muscle invasive bladder tumors display high levels of chromosomal aberrations. As cells deficient for nonhomologous end-joining (NHEJ) pathway components display increased genomic instability, we sought to determine the NHEJ repair characteristics of bladder tumors and correlate this with tumor stage and grade. A panel of 13 human bladder tumors of defined stage and grade were investigated for chromosomal aberrations by comparative genomic hybridization and for NHEJ repair fidelity and function. Repair assays were conducted with extracts made directly from bladder tumor specimens to avoid culture-induced phenotypic alterations and selection bias as only a minority of bladder tumors grow in culture. Four noninvasive bladder tumors (pTaG2), which were genetically stable, repaired a partially incompatible double-strand break (DSB) by NHEJ-dependent annealing of termini and fill-in of overhangs with minimal loss of nucleotides. In contrast, four muscle invasive bladder cancers (pT2-3G3), which displayed gross chromosomal rearrangements, repaired DSBs in an error-prone manner involving extensive resection and microhomology association. Four minimally invasive bladder cancers (pT1G3) had characteristics of both repair types. Error-prone repair in bladder tumors correlated with reduced KU DNA-binding and loss of TP53 function. In conclusion, there were distinct differences in DSB repair between noninvasive papillary tumors and higher stage/grade invasive cancers. End-joining fidelity correlated with stage and was increasingly error-prone as tumors became more invasive and KU binding activity reduced; these changes may underlie the different genomic profiles of these tumors. © 2008 Wiley-Liss, Inc. [source] Luminescent Solar Concentrators Employing PhycobilisomesADVANCED MATERIALS, Issue 31 2009Carlijn L. Mulder Phycobilisome-based luminescent solar concentrators (LSCs) take advantage of the photosynthetic antenna complexes of red algae and cyanobacteria. The phycobilisomes are successfully stabilized in a solid-state LSC matrix with minimal loss of performance. Comparison of samples with intact and decoupled complexes indicates that energy transfer within intact phycobilisomes results in a reduction of re-absorption losses by ,50%. [source] Smoothing and transporting video in QoS IP networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 7 2006Khaled Shuaib Abstract Real-time traffic such as voice and video, when transported over the Internet, demand stringent quality of service (QoS) requirements. The current Internet as of today is still used as a best effort environment with no quality guarantees. An IP-based Internet that supports different QoS requirements for different applications has been evolving for the past few years. Video streams are bursty in nature due to the instant variability of the video content being encoded. To help mitigate the transport of bursty video streams with minimal loss of information, rate-adaptive shapers (RASs) are usually being used to reduce the burstiness and therefore help preserve the desired quality. When transporting video over a QoS IP network, each stream is classified under a specific traffic profile to which it must conform, to avoid packet loss and picture quality degradation. In this paper we study, evaluate and propose RASs for the transport of video over a QoS IP network. We utilize the encoding video parameters for choosing the appropriate configuration needed to support the real-time transport of Variable Bit Rate (VBR) encoded video streams. The performance evaluation of the different RASs is based on the transport of MPEG-4 video streams encoded as VBR. The performance is studied based on looking at the effect of various parameters associated with the RASs on the effectiveness of smoothing out the burstiness of video and minimizing the probability of packet loss. Copyright © 2005 John Wiley & Sons, Ltd. [source] Efficient three-dimensional scene modeling and mosaicingJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 10 2009Tudor Nicosevici Scene modeling has a key role in applications ranging from visual mapping to augmented reality. This paper presents an end-to-end solution for creating accurate three-dimensional (3D) textured models using monocular video sequences. The methods are developed within the framework of sequential structure from motion, in which a 3D model of the environment is maintained and updated as new visual information becomes available. The proposed approach contains contributions at different levels. The camera pose is recovered by directly associating the 3D scene model with local image observations, using a dual-registration approach. Compared to the standard structure from motion techniques, this approach decreases the error accumulation while increasing the robustness to scene occlusions and feature association failures, while allowing 3D reconstructions for any type of scene. Motivated by the need to map large areas, a novel 3D vertex selection mechanism is proposed, which takes into account the geometry of the scene. Vertices are selected not only to have high reconstruction accuracy but also to be representative of the local shape of the scene. This results in a reduction in the complexity of the final 3D model, with minimal loss of precision. As a final step, a composite visual map of the scene (mosaic) is generated. We present a method for blending image textures using 3D geometric information and photometric differences between registered textures. The method allows high-quality mosaicing over 3D surfaces by reducing the effects of the distortions induced by camera viewpoint and illumination changes. The results are presented for four scene modeling scenarios, including a comparison with ground truth under a realistic scenario and a challenging underwater data set. Although developed primarily for underwater mapping applications, the methods are general and applicable to other domains, such as aerial and land-based mapping. © 2009 Wiley Periodicals, Inc. [source] Primary afferent dendrite degeneration as a cause of tinnitusJOURNAL OF NEUROSCIENCE RESEARCH, Issue 7 2007Carol A. Bauer Abstract Chronic tinnitus affects millions of people, but the mechanisms responsible for the development of this abnormal sensory state remain poorly understood. This study examined the type and extent of cochlear damage that occurs after acoustic trauma sufficient to induce chronic tinnitus in rats. Tinnitus was evaluated by using a conditioned suppression method of behavioral testing. Cochlear damage was assessed 6 months after acoustic trauma. There was minimal loss of inner and outer hair cells in the exposed cochleas of subjects demonstrating evidence of tinnitus. However, a significant loss of large-diameter fibers in the osseous spiral lamina of exposed cochleas of trauma subjects was observed. The significance of this finding in the context of a model of tinnitus is discussed. © 2007 Wiley-Liss, Inc. [source] A comparison of root surface instrumentation using two piezoelectric ultrasonic scalers and a hand scaler in vivoJOURNAL OF PERIODONTAL RESEARCH, Issue 1 2007H. Kawashima Background and Objective:, This study compared the effectiveness of two piezoelectric ultrasonic scalers and a hand scaler for subgingival scaling and root planing in vivo. Material and Methods:, Fifteen patients with advanced periodontal disease and with teeth scheduled for extraction were selected for this study. Three experimental groups of 10 teeth each were treated with one of two piezoelectric ultrasonic scalers [VectorÔ scaler and Enac® scaler] or with a hand scaler. Instrumentation was continued until the root surface felt hard and smooth to an explorer tip. The root surface characteristics after instrumentation were examined using scanning electron microscopy, and the amount of remaining calculus, roughness and loss of tooth substance were estimated using the remaining calculus index and roughness loss of tooth substance index. Results:, The remaining calculus index did not differ significantly among the three groups. The roughness loss of tooth substance index was significantly lower for the VectorÔ scaler and Enac® scaler groups than for the hand scaler group and also differed significantly between the VectorÔ scaler and Enac® scaler groups. Conclusion:, This study suggests that the VectorÔ scaler produces a smooth root surface with minimal loss of tooth substance. It is a reasonable choice for gentle periodontal maintenance treatment. [source] Stannous(II) trifluoromethane sulfonate: a versatile catalyst for the controlled ring-opening polymerization of lactides: Formation of stereoregular surfaces from polylactide "brushes"JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 20 2001Michael Möller Abstract A general method for the controlled synthesis of polylactide in solution and from solid supports is presented. The evaluation of stannous(II) trifluoromethane sulfonate [Sn(OTf)2] and scandium(III) trifluoromethane sulfonate [Sc(OTf)3] as catalysts for the ring-opening polymerization (ROP) of L -, D -, and L,D -lactide is described as a route to polylactide using mild and highly selective conditions. These triflate catalysts must be used in conjunction with a nucleophilic compound such as an alcohol that is the actual initiating species via the active metal alkoxide species. Consistent with this process, 1H NMR analysis revealed that the ,-chain-end bears the ester from the initiating alcohol, and upon hydrolysis of the active metal alkoxide chain end, a ,-hydroxyl chain end was clearly detected. Polymers of predictable molecular weights and narrow polydispersities were obtained in high yields in accordance with a controlled polymerization process. The addition of base either as a solvent or additive significantly enhanced the polymerization rate with minimal loss to the polymerization control. The ROP of lactide isomers from an initiator, HO(CH2CH2O)3(CH2)11SH, self-assembled onto a gold surface using Sn(OTf)2 produced polylactide brushes under living conditions and provides the opportunity to prepare stereoregular or chiral surfaces by polymerization of enantiomerically pure monomers. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3529,3538, 2001 [source] Zirconium hydroxide effectively immobilizes and concentrates human enteric virusesLETTERS IN APPLIED MICROBIOLOGY, Issue 5 2002D.H. D'Souza Background: Detection of human enteric viruses in foods and environmental samples requires concentration of viruses from complex matrices before application of molecular or cultural methods. Previous studies have described the use of zirconium hydroxide to concentrate bacteria from clinical, environmental, and food samples. Aims: Our study describes the application of zirconium hydroxide to concentrate human enteric viruses. Methods: Poliovirus type 1, hepatitis A virus (HAV) strain HM-175, and Norwalk virus (NV) were used as models. Virus recovery was evaluated both as loss to discarded supernatants and as recovery in the precipitated pellets. Results: Poliovirus type 1, based on the plaque assay recoveries, ranged from 16 to 59% with minimal loss to the supernatant (1,5%). For both HAV and NV, RT-PCR amplicons of appropriate sizes were detected and confirmed in the pellet fraction with no visible amplicons from the supernatant. Significance and Impact of the Study: This rapid and inexpensive method shows promise as an alternative means to concentrate enteric viruses. [source] Polymeric Toughening of Particle Filled Cyanate Ester CompositesMACROMOLECULAR MATERIALS & ENGINEERING, Issue 10 2005Tim J. Wooster Abstract Summary: The present study examines the effect of polymeric tougheners on the performance of silica filled cyanate ester composites. The polymeric tougheners used have been shown to enhance cyanate ester tougheners in binary toughener/matrix systems. Tougheners that were able to form a favourable phase-separated morphology resulted in the greatest increase in crack resistance. The addition of these tougheners resulted in minimal loss of strength, and a slight decrease in modulus. Importantly the viscosity of the compounded systems was low enough for them to be readily processable. Whilst conserving most secondary properties, toughener addition did result in a slight increase in composite hydrolytic degradation. This issue was linked to the additive/ additive compounding processes. Removal of this extra moisture should eliminate this concern, permitting the used of these composites in electronic applications. Effect of ETBN content on the crack resistance of particle filled cyanate ester composites and SEM image of 15 matrix wt.-% ETBN. [source] Dppc+PF6,,PdCl2,[bmim][PF6],a copper-free recyclable catalytic system for Sonogashira coupling reactionAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 5 2007Jintao Guan Abstract An air-stable, copper-free and highly efficient Dppc+PF6,,PdCl2,[bmim][PF6] catalytic system has been developed for the Sonogashira coupling reaction of aryl iodides with various aryl- and alkylacetylenes. The catalytic system allows for facile separation and can be recycled at least eight times with minimal loss of activity. Copyright © 2007 John Wiley & Sons, Ltd. [source] Effect of Substrate Temperature on the Plasma Polymerization of Poly(methyl methacrylate),CHEMICAL VAPOR DEPOSITION, Issue 1 2006B. Casserly Abstract Low-power, plasma-enhanced (PE)CVD together with polymerization of methyl methacrylate (MMA) can be used to deposit thin films of poly(methyl methacrylate) (PMMA) with,minimal loss of functional groups, as shown by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and Raman spectrometry (RS). Retention of functional groups decreases with increased substrate temperature, corresponding to decreased deposition rates. From XPS data, the calculated percentage loss of functional groups ranges from 0.9,% to 43.4,%, changing as a function of deposition conditions. RS confirms the presence of C=C bonds in the polymer backbone as a result of scission of the ester group from MMA. The thermal properties of PECVD-produced films from MMA can be tailored by varying the substrate temperature. Onset of thermal decomposition increases with increased substrate temperature by eliminating thermally labile peroxide linkages in the polymer backbone, and by crosslinking that occurs at radical sites generated via scission of functional group bonds. The post-anneal thicknesses of the remaining polymer is of the order of 4,nm or less, indicating that low-power PECVD of PMMA is a viable candidate to act as a sacrificial material for air-gap fabrication. [source] Fc, receptor polymorphisms and periodontal status: a prospective follow-up studyJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 10 2006D. L. Wolf Abstract Aims: The aims of this study were to assess: (i) the distribution of Fc, receptor polymorphisms among patients with chronic periodontitis ("cases") and control subjects with no/minimal loss of periodontal tissue support in a Caucasian population; (ii) whether these polymorphisms can serve as severity markers for periodontitis; and (iii) whether they have any bearing on the response to periodontal therapy. Methods: The study sample consisted of 132 cases and 73 controls of comparable age and gender. Full-mouth periodontal status was assessed. Subgingival plaque (PL) samples and blood samples were obtained and analysed with respect to 19 bacterial species and homologous serum immunoglobulin G titres. Polymorphisms in the Fc, receptor IIa (131R/H) and IIIb (NA1/NA2) were assessed by polymerase chain reaction. Patients underwent periodontal therapy and were followed up at 4 and 30 months. Results: Neither polymorphism showed a skewed distribution among cases and controls. At baseline, periodontitis patients with Fc, RIIa-H/H131 genotype had more PL and deeper pockets than patients in other genotype groups (p<0.05). Both bacterial levels and antibody titres were unrelated to genotype. The longitudinal analysis failed to detect an association between genotype and response to periodontal therapy. Conclusions: The present data failed to demonstrate a clinically relevant relationship between the Fc, receptor IIa (131R/H) or IIIb (NA1/NA2) polymorphism and periodontal status. [source] | ||||||||||||||||||||||||||||