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Several Techniques (several + techniques)
Selected AbstractsBulk Heterojunction Solar Cells: The Role of Processing in the Fabrication and Optimization of Plastic Solar Cells (Adv. Mater.ADVANCED MATERIALS, Issue 14-15 200915/2009) Alan Heeger and co-workers report on page 1521 on the role of processing methodology in the fabrication and optimization of bulk heterojunction (BHJ) ,plastic' solar cells. Several techniques that have recently been used to optimize the BHJ nanomorphology are discussed and compared and some insights are given into the mechanisms behind these various techniques. The cover image depicts a multilayer solar cell ribbon along with the polymer, fullerene, and solvent additive, which were used to fabricate a low bandgap polymer solar cell with greater than 5% power conversion efficiency. [source] Adaptive embedded unstructured grid methodsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 3 2004Rainald Löhner Abstract A simple embedded domain method for node-based unstructured grid solvers is presented. The key modification of the original, edge-based solver is to remove all geometry-parameters (essentially the normals) belonging to edges cut by embedded surface faces. Several techniques to improve the treatment of boundary points close to the immersed surfaces are explored. Alternatively, higher-order boundary conditions are achieved by duplicating crossed edges and their endpoints. Adaptive mesh refinement based on proximity to or the curvature of the embedded CSD surfaces is used to enhance the accuracy of the solution. User-defined or automatic deactivation for the regions inside immersed solid bodies is employed to avoid unnecessary work. Several examples are included that show the viability of this approach for inviscid and viscous, compressible and incompressible, steady and unsteady flows, as well as coupled fluid,structure problems. Copyright © 2004 John Wiley & Sons, Ltd. [source] Blending PP with PA6 industrial wastes: Effect of the composition and the compatibilizationJOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2008Mohamed Jaziri Abstract Blending polypropylene to recycled PA6 industrial wastes at different compositions, with and without compatibilizer PPgMA was produced in a corotating twin screw extruder where, polypropylene acts as the polymer matrix and polyamide as the dispersed phase. Several techniques were used to investigate the morphology, thermal, viscoelastic and tensile properties of these blend. Binary PP/PA6 blends showed the presence of PA6 particles dispersed in the PP continuous phase and exhibited a coarse morphology. Increasing PA6 contents in the blend increased their crystallinity and their size and improved the tensile properties at weak deformation. In addition to compatibilizer PPgMA, the morphology shows lower diameters and a decrease in size of the dispersed PA6 particles. The interfacial adhesion was also improved, as a result of the creation of an interphase that was formed by the interaction between the formed PPgPA6 copolymer in situ and both phases. This interphase induced an improvement in tensile properties. The PPgPA6 copolymer generated by the interphase was identified with DMA analysis thanks to an additional transition in loss modulus curves. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Hydrolytic degradation of poly(ethylene terephthalate)JOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2007Seyed Saeid Hosseini Abstract Molecular weight is an important factor in the processing of polymer materials, and it should be well controlled to obtain desired physical properties in final products for end-use applications. Degradation processes of all kinds, including hydrolytic, thermal, and oxidative degradations, cause chain scission in macromolecules and a reduction in molecular weight. The main purpose of this research is to illustrate the importance of degradation in the drying of poly(ethylene terephthalate) (PET) before processing and the loss of weight and mechanical properties in textile materials during washing. Several techniques were used to investigate the hydrolytic degradation of PET and its effect on changes in molecular weight. Hydrolytic conditions were used to expose fiber-grade PET chips in water at 85°C for different periods of time. Solution viscometry and end-group analysis were used as the main methods for determining the extent of degradation. The experimental results show that PET is susceptible to hydrolysis. Also, we that as the time of retention in hydrolytic condition increased, the molecular weight decreases, but the rate of chain cleavage decreased to some extent, at which point there was no more sensible degradation. The obtained moisture content data confirmed the end-group analysis and viscometry results. Predictive analytical relationships for the estimation of the extent of degradation based on solution viscosity and end-group analysis are presented. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2304,2309, 2007 [source] Bioprocesses for the removal of nitrogen oxides from polluted airJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 5 2005Yaomin Jin Abstract Nitrogen oxides (NOx) of environmental concern are nitrogen monoxide (NO) and nitrogen dioxide (NO2). They are hazardous air pollutants that lead to the formation of acid rain and tropospheric ozone. Both pollutants are usually present simultaneously and are, therefore, called NOx. Another compound is N2O which is found in the stratosphere where it plays a role in the greenhouse effect. Concern for environmental and health issues coupled with stringent NOx emission standards generates a need for the development of efficient low-cost NOx abatement technologies. Under such circumstances, it becomes mandatory for each NOx-emitting industry or facility to opt for proper NOx control measures. Several techniques are available to control NOx emissions: selective catalytic reduction (SCR), selective non-catalytic reduction (SNCR), adsorption, scrubbing, and biological methods. Each process offers specific advantages and limitations. Since bioprocesses present many advantages over conventional technologies for flue gas cleaning, a lot of interest has recently been shown for these processes. This article reviews the major characteristics of conventional non-biological technologies and recent advances in the biological removal of NOx from flue gases based on the catalytic activity of either eucaryotes or procaryotes, ie nitrification, denitrification, the use of microalgae, and a combined physicochemical and biological process (BioDeNOx). Relatively uncomplicated design and simple operation and maintenance requirements make biological removal a good option for the control of NOx emissions in stationary sources. Copyright © 2005 Society of Chemical Industry [source] Characterisation of an inclusion complex between cladribine and 2-hydroxypropyl-,-cyclodextrin,JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 9 2008Valeria Van Axel Castelli Abstract Parenterally administered cladribine (2-chloro-2,-deoxyadenosine) has demonstrated promising efficacy and safety in clinical trials in patients with multiple sclerosis (MS). An oral formulation of this small molecule would be an attractive option for patients. Here, we describe the chemical characterisation of the inclusion complex between cladribine and the drug carrier molecule 2-hydroxypropyl-,-cyclodextrin (2-HP-,-CD). Several techniques were used to analyse the complex both in solution and in the solid state. These analyses provided evidence that the inclusion complex cannot be simply reduced to the sum of the two species, as it shows behaviour different from that of the physical mixture of the two components. Furthermore, solution nuclear magnetic resonance spectroscopy demonstrated the existence of an inclusion complex between cladribine and 2-HP-,-CD. Importantly, analysis of a tablet formulation demonstrated that the chemical characteristics of the inclusion complex are not affected by the manufacturing process, and that the complex is stable during storage. This tablet formulation is currently under investigation for the treatment of patients with MS. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97:3897,3906, 2008 [source] Microenvironmental pH modulation in solid dosage formsJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 5 2007Sherif I. Farag Badawy Abstract There are many reports in the literature referring to the effect of ,microenvironmental pH' on solid dosage form performance, particularly stability and dissolution profiles. Several techniques have been proposed for the measurement of the microenvironmental pH. Those techniques use certain assumptions and approximations and many of them employ a solution calibration curve of a probe to predict hydrogen ion activity in a substantially dry solid. Despite the limitation of the methodology, it is clear from the literature that microenvironmental pH has a significant impact on stability of compounds which demonstrate pH dependent stability in solution. Degradation kinetics of such compounds, and in some cases degradation profile as well, are dependent on the microenvironmental pH of the solid. Modulation of the microenvironmental pH through the use of pH modifiers can hence prove to be a very effective tool in maximizing solid dosage form stability. Judicial selection of the appropriate pH modifier, its concentration and the manufacturing process used to incorporate the pH modifier is necessary to enhance stability. Control of microenvironmental pH to maximize stability can be achieved without the use of pH modifier in some cases if an appropriate counter ion is used to provide an inherently optimal pH for the salt. Microenvironmental pH modulation was also shown to control the dissolution profile of both immediate and controlled release dosage forms of compounds with pH dependent solubility. The pH modifiers have been used in conjunction with high energy or salt forms in immediate release formulations to minimize the precipitation of the less soluble free form during initial dissolution. Additionally, pH modifiers were utilized in controlled release dosage forms of weakly basic drugs which exhibit diminished release in dissolution media with high pH. The incorporation of acidic pH modifiers in the controlled release formulation increases the solubility of the basic drug even as the high pH dissolution medium enters into the dosage form hence increasing drug release rate. © 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 96: 948,959, 2007 [source] Analysis of the surface energy of pharmaceutical powders by inverse gas chromatographyJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 2 2002Ian M. Grimsey Abstract The behavior of pharmaceutical solids, during either processing or use, can be noticeably affected by the surface energetics of the constituent particles. Several techniques exist to measure the surface energy, for example, sessile drop, and dynamic contact angle measurements. Inverse gas chromatography (IGC) is an alternative technique where the powder surface is characterized by the retention behavior of minute quantities of well-characterized vapors that are injected into a column containing the material of interest. Recently published articles using IGC on pharmaceutical powders have ranged from linking surface energetic data with triboelectric charging to studying the effect of surface moisture on surface energetics. Molecular modelling has also recently been used to explore the links between IGC data and the structural and chemical factors that influence surface properties, thereby achieving predictive knowledge regarding powder behavior during processing. In this minireview, the reported applications of IGC in the analysis of pharmaceutical powders are summarized and the major findings highlighted. © 2002 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 91:571,583, 2002 [source] Small-for-size liver syndrome after auxiliary and split liver transplantation: Donor selectionLIVER TRANSPLANTATION, Issue 9 2003Nigel Heaton Small-for-size liver grafts can be defined by a recognizable clinical syndrome that results from the transplantation of too small a functional mass of liver for a designated recipient. A graft to recipient body weight ratio less than 0.8, impaired venous inflow, and enhanced metabolic demands in patients with poor clinical conditions must be considered as main factors leading to the small-for-size syndrome (SFSS) when using living and cadaveric partial grafts such as split and auxiliary liver grafts. Increased risk of graft dysfunction is currently observed in fatty infiltration of more than 30%, abnormal liver test results (especially bilirubin and gamma glutaryl transferase), and other donor risk factors such as high inotrope administration and donor stay in the intensive care unit (>5 days). Older donors are especially vulnerable to prolonged cold ischemia and high inotrope levels, giving rise to early graft dysfunction and prolonged cholestasis. Increased metabolic need on a functionally small-for-size graft predisposes to surgical and septic complications and poorer survival. Splitting livers into right and left lobe grafts increases the potential risk of small-for-size grafts for both recipients. Several techniques of venous outflow reconstruction/implantation have been proposed to reduce the risk of obstruction postoperatively. Prevention and management of SFSS will improve in parallel with the increased experience, allowing us optimum usage of available organs and reducing overall morbidity and mortality. (Liver Transpl 2003;9:S26-S28.) [source] Maxillary reconstruction using anterolateral thigh flap and bone graftsMICROSURGERY, Issue 6 2009Bernardo Bianchi M.D. Background: Loss of the maxilla and midfacial bone buttresses after tumor resections can lead to severe functional and esthetic consequences. The loss of palate function may lead to oro-nasal communication, nasal speech, and oral intake difficulties. Several techniques have been proposed for maxillary defects reconstruction including prosthesis, locoregional flaps, or free flaps. The authors propose the use of anterolateral thigh free flap and iliac crest, or calvaria bone graft association for reconstruction of this kind of defects. Methods: Between November 2003 and June 2007, eight patients underwent maxillectomies, with preservation of the orbital contents and simultaneous reconstruction using this technique. Results: All the flaps were harvested and transplanted successfully. No major complication occurred and only one patient developed a palatal dehiscence with partial necrosis of the skin of the flap. There were no complications at the donor sites. Speech was assessed as normal in five patients, intelligible in two patients, and poor in one patient. Six patients returned to normal diets, while two patients were restricted to soft diets. The esthetic results were evaluated by the patients themselves as good (in five cases) and acceptable (in two cases). In the remaining case, the esthetic result was deemed to be poor, due to ectropion and poor color matching of the skin used for the external coverage. Conclusion: The good results obtained using this technique encourage the choice of the association of anterolateral thigh and bone grafts for reconstructing maxillary complex defects. © 2009 Wiley-Liss, Inc. Microsurgery 2009. [source] On L1 -minimization in optimal control and applications to roboticsOPTIMAL CONTROL APPLICATIONS AND METHODS, Issue 6 2006G. Vossen Abstract In this paper, we analyze optimal control problems with control variables appearing linearly in the dynamics. We discuss different cost functionals involving the Lp -norm of the control. The case p = 0 represents the time-optimal control, the case p > 1 yields a standard smooth optimal control problem, whereas the case p = 1 leads to a nonsmooth cost functional. Several techniques are developed to deal with the nonsmooth case p = 1. We present a thorough theoretical discussion of the necessary conditions. Two types of numerical methods are developed: either a regularization technique is used or an augmentation approach is applied in which the number of control variables is doubled. We show the precise relations between the L1 -minimal control and the bang,bang or singular controls in the augmented problem. Using second-order sufficient conditions (SSC) for bang,bang controls, we obtain SSC for L1 -minimal controls. The different techniques and results are illustrated with an example of the optimal control for a free-flying robot which is taken from Sakawa. Copyright © 2006 John Wiley & Sons, Ltd. [source] Addition of clonidine and fentanyl: comparison between three different regional anesthetic techniques in circumcisionPEDIATRIC ANESTHESIA, Issue 11 2005ZOUHER A NAJA MD Summary Background :,Several techniques have been used for alleviating postcircumcision pain with regional anesthetics being more effective than systemic opioids. Our aim was to compare the effectiveness of dorsal penile block, ring block (RB) and dorsal penile block associated with RB in reducing postcircumcision pain in children. Methods :,We conducted a prospective randomized double-blind clinical trial on 100 boys aged between 1 month and 5 years undergoing elective circumcision. Each 20 ml of local anesthetic mixture contained 9 ml lidocaine 1% without epinephrine, 9 ml bupivacaine 0.5%, 1 ml fentanyl (50 ,g·ml,1) and 1 ml clonidine (75 ,g·ml,1). They were allocated to one of three groups: 33 boys were given a RB with 1,1.5 ml (group 1), 32 had a dorsal penile block with 1.5,4 ml (group 2) and 35 had a combined ring and dorsal penile block with 2.5,5 ml of anesthetic mixture based on the child's age. Results :,Ninety-one children (91%) completed the clinical trial (three failed blocks and six follow-up losses). The groups were similar with regard to age, weight, height, duration of surgery and hemodynamic status. The average pain scores were significantly higher with a RB compared with the other two groups (P < 0.05) for the first postoperative day. RB children and dorsal penile block children consumed significantly more analgesics for the first six postoperative hours (P < 0.05). The surgeon's satisfaction was significantly higher with the ring + dorsal penile block group (100%) compared with the other two groups (P = 0.032). Conclusion :,Dorsal penile block plus RB technique is superior to dorsal penile block alone and RB alone in reducing postcircumcision pain in children. [source] Toward a better analysis of secreted proteins: the example of the myeloid cells secretomePROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 11 2007Mireille Chevallet Abstract The analysis of secreted proteins represents a challenge for current proteomics techniques. Proteins are usually secreted at low concentrations in the culture media, which makes their recovery difficult. In addition, culture media are rich in salts and other compounds interfering with most proteomics techniques, which makes selective precipitation of proteins almost mandatory for a correct subsequent proteomics analysis. Last but not least, the non-secreted proteins liberated in the culture medium upon lysis of a few dead cells heavily contaminate the so-called secreted proteins preparations. Several techniques have been used in the past for concentration of proteins secreted in culture media. These techniques present several drawbacks, such as coprecipitation of salts or poor yields at low protein concentrations. Improved techniques based on carrier-assisted TCA precipitation are described and discussed in this report. These techniques have been used to analyze the secretome of myeloid cells (macrophages, dendritic cells) and enabled to analyze proteins secreted at concentrations close to 1,ng/mL, thereby allowing the detection of some of the cytokines (TNF, IL-12) secreted by the myeloid cells upon activation by bacterial products. [source] Conjugated Macrocycles as Active Materials in Nonlinear Optical Processes: Optical Limiting Effect with Phthalocyanines and Related CompoundsTHE CHEMICAL RECORD, Issue 3 2002Michael Hanack Abstract An overview of the optical limiting (OL) processes in phthalocyanines and related compounds is presented, particularly a description of the synthesis and relevant optical properties of a series of axially substituted indium(III), titanium(IV), phthalo- and naphthalocyanines, and octaarylporphyrazines. Several techniques, such as transient absorption, Z-scan, and degenerate four-wave mixing, were used to assess the optical properties and OL performance of the investigated compounds. The versatility of the methods of organic synthesis leads to the achievement of effective systems in terms of OL performance through the appropriate combination and modulation of several structural components. The chemistry of the macrocycles here considered allows the variation of the different chemical features, such as the degree of electronic conjugation of the macrocycle and the nature of the ring substituents, the central atom, and the ligands attached to the central atom. © 2002 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 2: 129,148, 2002: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.10024 [source] Robotic-assisted single-incision right colectomy: early experienceTHE INTERNATIONAL JOURNAL OF MEDICAL ROBOTICS AND COMPUTER ASSISTED SURGERY, Issue 4 2009Matthew B. Ostrowitz Abstract Background Application of laparoendoscopic single-site surgery (LESS) is increasing across surgical disciplines. In addition to the possibility of decreased postoperative pain, LESS offers better cosmesis with virtually ,scarless' surgeries, while avoiding the increased costs and complexity of natural orifice surgery. Instrument conflict minimization often requires the crossing of articulating instruments, which we believe can be more intuitively facilitated using the daVinci-S® robotic system. We describe our early experience with three robotic single-incision right hemicolectomies. Methods Three robotic single-incision right hemicolectomies were performed using the daVinci-S robotic system, utilizing a single 4 cm incision through or around the umbilicus. The procedure was performed using three robotic arms, a 12 mm camera and two 8 mm robotic ports. A medial to lateral approach was used and an extracorporeal resection and anastomosis was performed after undocking the robot. Results There were no intraoperative or postoperative complications. Average operative time was 152 min. The first case was converted to non-robotic single-incision right hemicolectomy during mobilization of the ascending colon, due to uncontrollable air leakage around the ports. The second and third cases were successfully completed without air loss by purse-stringing sutures around each individual port and the use of the SILSÔ port, respectively. Conclusions Robotic-assisted single-incision right hemicolectomy can be successfully and safely performed using the daVinci-S robotic system. Several techniques may be employed to prevent the loss of pneumoperitoneum. We believe right hemicolectomy lends itself to single-site surgery because specimen extraction requires a 4 cm incision and may confer patient benefit, with decreased postoperative pain and improved cosmesis. By crossing the robotic instruments and reassigning control of the arms, the robot represents a means to help perform these procedures safely by allowing them to be performed in a more intuitive fashion. Copyright © 2009 John Wiley & Sons, Ltd. [source] Viewing apoptosis through a ,TUNEL'THE JOURNAL OF PATHOLOGY, Issue 3 2001J. A. Walker Abstract Apoptosis has an important role in carcinogenesis and cancer treatment. The end result of this complex pathway is the formation of apoptotic bodies. These can be difficult to quantify accurately, but quantitation is important if we wish to study this process. Several techniques are available which can help. ,TUNEL' is discussed, with its potential drawbacks, and newer antibody techniques, such as M30 and caspase 3, are then reviewed. Copyright © 2001 John Wiley & Sons, Ltd. [source] Minimally invasive surgery for esophageal cancerASIAN JOURNAL OF ENDOSCOPIC SURGERY, Issue 3 2010AJ Greenstein Abstract Background: Esophageal cancer is among the most deadly cancers worldwide, and esophagectomy remains the standard of care in trying to cure this. Efforts to decrease the incidence of complications in esophagectomy without compromising the efficacy of the procedure have stimulated interest in minimally invasive esophagectomy (MIE), and a wide variety of MIE techniques have been refined by surgeons at specialized centers worldwide. Data sources: Systematic PubMed searches identified articles related to MIE technique, complications, and outcomes. Conclusions: Several techniques have been developed for MIE, none of which has been deemed superior, but as a whole, they represent a safe alternative to open surgery. Available results from case series and comparative studies suggest trends towards improved short-term outcomes with equivalent efficacy but without definitive advantages. [source] Economical Feasibility Evaluation of an Ethanol Injection Liposome Production PlantCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 1 2010O. R. Justo Abstract Over the past few decades liposomes, which are lipid vesicles useful for the controlled release of numerous bioactive compounds, have attracted significant industrial interest. Several techniques have evolved for the manufacture of liposomes on a small scale. However, production on a commercially feasible scale is still somewhat limited. Therefore, this research intends to evaluate the scale-up potential of a liposome production unit using the ethanol injection method, through preliminary economical feasibility estimation, as an addendum to a pre-existing bioactive compound manufacture plant, with the aim of increasing the compound aggregate value. The ethanol injection technique is selected due to its simplicity and low cost, characteristics that make it easily scalable. The preliminary economic evaluation involves the assessment of capital investment, estimation of operating costs, and analysis of profitability. The results of the economic analysis suggest that the process is economically feasible for a plant with a daily production capacity of 288 L of liposomal suspension. [source] Intraoperative floppy iris syndrome (IFIS): a practical approach to medical and surgical considerations in cataract extractionsACTA OPHTHALMOLOGICA, Issue 7 2009Allan Storr-Paulsen Abstract. Intraoperative floppy iris syndrome (IFIS) during cataract surgery is characterized by iris fluttering, iris prolapse towards the incisions, and a progressive pupillary constriction leading to high rates of complications. The syndrome has been reported following the treatment of benign prostatic hyperplasia with ,-1a adrenergic receptor inhibitors, especially tamsulosin. The present paper describes the syndrome and discusses its pharmacological background. Several techniques to prevent and to deal with the syndrome are presented. [source] Data partitioning-based parallel irregular reductionsCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 2-3 2004Eladio Gutiérrez Abstract Different parallelization methods for irregular reductions on shared memory multiprocessors have been proposed in the literature in recent years. We have classified all these methods and analyzed them in terms of a set of properties: data locality, memory overhead, exploited parallelism, and workload balancing. In this paper we propose several techniques to increase the amount of exploited parallelism and to introduce load balancing into an important class of these methods. Regarding parallelism, the proposed solution is based on the partial expansion of the reduction array. Load balancing is discussed in terms of two techniques. The first technique is a generic one, as it deals with any kind of load imbalance present in the problem domain. The second technique handles a special case of load imbalance which occurs whenever a large number of write operations are concentrated on small regions of the reduction arrays. Efficient implementations of the proposed optimizing solutions for a particular method are presented, experimentally tested on static and dynamic kernel codes, and compared with other parallel reduction methods. Copyright © 2004 John Wiley & Sons, Ltd. [source] WHEN MISSING DATA ARE NOT MISSING: A NEW APPROACH TO EVALUATING SUPPLEMENTAL HOMICIDE REPORT IMPUTATION STRATEGIES,CRIMINOLOGY, Issue 4 2008TIM WADSWORTH The Supplemental Homicide Reports (SHR) are widely used in criminological research and inform a broad range of research topics and subsequent policy applications. A serious issue with the SHR is missing information about the offender and incident in many recorded homicides. Although it is convenient to discard cases with missing data before analysis, such discarding is not theoretically justified and can lead to incorrect substantive conclusions. Recently, several techniques for imputing missing SHR data have been proposed, but it is difficult to evaluate their effectiveness. This research presents a new approach to testing and evaluating SHR imputation techniques. Offender data that are missing in the SHR are often found in police records available for individual cities. We examine similarities and differences among cases with known offender characteristics in the SHR, cases with such information missing in the SHR but available in police records, and cases with such information missing in both sources. We then use these data sets to evaluate four different imputation techniques suggested in the literature (Fox, 2004; Messner, Deane, and Beaulieu, 2002; Pampel and Williams, 2000; Regoeczi and Riedel, 2003). We apply each imputation technique to the SHR, and for cases with information missing in the SHR but known in the police records, we see how well the imputed values correspond both with the individual known values and with the overall distributions in the police records. We discuss the outcome of our assessment of these strategies, and we outline important implications this assessment has for research using SHR data. [source] Growth of tetrakis thiourea potassium iodide as new second order optical materialCRYSTAL RESEARCH AND TECHNOLOGY, Issue 4 2008J. Thomas Joseph Prakash Abstract A novel organometallic nonlinear optical (NLO) crystal, namely thiourea complex of tetrakis thiourea potassium iodide (TTPI), has been grown by slow evaporation solution growth technique. The harvested crystal is large in size. To our knowledge there is no report is available for the bulk size single crystal of TTPI. This material has a positive temperature coefficient and has been grown by slow evaporation solution growth technique. The grown crystal have been characterized by employing several techniques such as single crystal and powder X-ray diffraction, FTIR, UV-Vis-NIR spectra, thermo gravimetric analyses respectively. Etching studies have also been carried out in order to know the surface defects on the as grown specimen of TTPI. The relative second harmonic generation efficiency have been tested by using Nd:YAG laser as source. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Cells meeting our immunophenotypic criteria of endothelial cells are large plateletsCYTOMETRY, Issue 2 2007Michiel H. Strijbos Abstract Background Circulating endothelial cells (CEC) are shed from damaged vasculature, making them a rational choice to serve as surrogate marker for vascular damage. Currently, various techniques and CEC definitions are in use, and their standardization and validation is needed. A flow cytometric single platform assay defining CEC as forward light scatter (FSC)low-to-intermedate, sideward light scatter (SSC)low, CD45,, CD31++ and CD146+ is a promising approach to enumerate CEC because of its simplicity (Mancuso et al., Blood 2001;97:3658,3661). Here, we set out to confirm the endothelial nature of these cells. Methods We isolated cells with a FSClow-to-intermediate, SSClow, CD31++, CD45dim immunophenotype (termed "cells meeting our immunophenotypic criteria for endothelial cells" [CMOIC]) from healthy donors to study the expression of endothelium-associated markers using several techniques. Special attention was paid to reagents identifying the endothelial cell-specific marker CD146. We compared antigen expression patterns of CMOIC with those of the HUVEC endothelial cell line and lymphocytes. Electron microscopy was used to detect the presence of endothelial cell-specific Weibel,Palade bodies in the sorted cells. Results CD146 expression was negative on CMOIC for all tested CD146 mAbs, but positive on HUVEC cells and a minor subset of T lymphocytes. Using flow cytometry, we found no expression of any endothelium-associated marker except for CD31 and CD34. HUVEC cells were positive for all endothelial markers except for CD34. Evaluation of CMOIC morphology showed a homogenous population of cells with a highly irregular nucleus-like structure and positive endothelial immunohistochemistry. CMOIC contained neither nuclei nor DNA. Electron microscopy revealed the absence of a nucleus, the absence of endothelial specific Weibel,Palade bodies, and revealed CMOIC to be large platelets. Conclusion The vast majority of cells with the immunophenotype FSClow-to-intermediate, SSClow, CD45,, CD31++ do not express CD146 and are large platelets rather than endothelial cells. © 2007 Clinical Cytometry Society. [source] Multidisciplinary approach of complicated crown fractures of both superior central incisors: a case reportDENTAL TRAUMATOLOGY, Issue 4 2008Anca Silvia Vâlceanu Since the development of the adhesive dentistry, many case reports of crown fractures restored using adhesive reattachment techniques were published. Complex cases, in which more than one tooth are involved, with fractures differing from each other, require specific treatment of each fracture, taking different advantages of the different remaining tooth structures. This case report describes a patient with dissimilar crown fractures of both superior central incisors. After the endodontic treatment, the patient was treated using the combination of several techniques: periodontal surgery (crown lengthening with apically repositioned flap and osseous resective surgery), adhesive technique and cast restoration plus esthetic crown. The periodontal procedure re-created the biologic width and proved to be a reliable adjunctive procedure to the adhesive and the prosthetic techniques used. [source] The Art of Repair in Surgical Hair Restoration Part I: Basic Repair StrategiesDERMATOLOGIC SURGERY, Issue 9 2002Robert M. Bernstein MD background. An increasingly important part of many hair restoration practices is the correction of hair transplants that were performed using older, outdated methods, or the correction of hair transplants that have left disfiguring results. The skill and judgment involved in these repair procedures often exceed those needed to operate on patients who have had no prior surgery. The use of small grafts alone does not protect the patient from poor work. Errors in surgical and aesthetic judgment, performing procedures on noncandidate patients, and the failure to communicate successfully with patients about realistic expectations remain major problems. objective. This two-part series presents new insights into repair strategies and expands upon several techniques previously described in the hair restoration literature. The focus is on creative aesthetic solutions to solve the supply/demand limitations inherent in most repairs. This article is written to serve as a guide for surgeons who perform repairs in their daily practices. methods. The repairs are performed by excision with reimplantation and/or by camouflage. Follicular unit transplantation is used for the restorative aspects of the procedure. results. Using punch or linear excision techniques allows the surgeon to relocate poorly planted grafts to areas that are more appropriate. In special situations, removal of grafts without reimplantation can be accomplished using lasers or electrolysis. The key elements of camouflage include creating a deep zone of follicular units, angling grafts in their natural direction, and using forward and side weighting of grafts to increase the appearance of fullness. The available donor supply is limited by hair density, scalp laxity, and scar placement. conclusion. Presented with significant cosmetic problems and severely limited donor reserves, the surgeon performing restorative hair transplantation work faces distinct challenges. Meticulous surgical techniques and optimal utilization of a limited hair supply will enable the surgeon to achieve the best possible cosmetic results for patients requiring repairs. [source] Models for the estimation of a ,no effect concentration'ENVIRONMETRICS, Issue 1 2002Ana M. Pires Abstract The use of a no effect concentration (NEC), instead of the commonly used no observed effect concentration (NOEC), has been advocated recently. In this article models and methods for the estimation of an NEC are proposed and it is shown that the NEC overcomes many of the objections to the NOEC. The NEC is included as a threshold parameter in a non-linear model. Numerical methods are then used for point estimation and several techniques are proposed for interval estimation (based on bootstrap, profile likelihood and asymptotic normality). The adequacy of these methods is empirically confirmed by the results of a simulation study. The profile likelihood based interval has emerged as the best method. Finally the methodology is illustrated with data obtained from a 21 day Daphnia magna reproduction test with a reference substance, 3,4-dichloroaniline (3,4-DCA), and with a real effluent. Copyright © 2002 John Wiley & Sons, Ltd. [source] Improved Estimates of Correlation Coefficients and their Impact on Optimum PortfoliosEUROPEAN FINANCIAL MANAGEMENT, Issue 3 2006Edwin J. Elton G11 Abstract To implement mean variance analysis one needs a technique for forecasting correlation coefficients. In this article we investigate the ability of several techniques to forecast correlation coefficients between securities. We find that separately forecasting the average level of pair-wise correlations and individual pair-wise differences from the average improves forecasting accuracy. Furthermore, forming homogenous groups of firms on the basis of industry membership or firm attributes (e.g. size) improves forecast accuracy. Accuracy is evaluated in two ways: First, in terms of the error in estimating future correlation coefficients. Second, in the characteristics of portfolios formed on the basis of each forecasting technique. The ranking of forecasting techniques is robust across both methods of evaluation and the better techniques outperform prior suggestions in the literature of financial economics. [source] Molecular Interaction between a Gadolinium,Polyoxometalate and Human Serum AlbuminEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 34 2009Li Zheng Abstract Polyoxometalates (POMs) show promising antibacterial, antiviral (particularly anti-HIV), antitumor, and anticancer activities, but the mechanism of these potential therapeutic effects remains to be elucidated at the molecular level. The interaction between the Gd-containing tungstosilicate [Gd(,2 -SiW11O39)2]13, and human serum albumin (HSA) was studied by several techniques. Fluorescence spectroscopy showed an energy transfer between the single tryptophan residue of HSA and the POM. Circular dichroism led to the conclusion that the POM significantly altered the secondary structure of HSA. Isothermal titration calorimetry revealed an enthalpy-driven binding reaction between HSA and the POM, resulting in the formation of a 1:1 complex.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Cover Picture: A Novel Method to Orient Semiconducting Polymer Films (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 7 2005Mater. Abstract A new technique for orienting thin polymer semiconductor films is reported by Österbacka and co-workers on p.,1095. The technique uses the mechanical force of a shrinking polymer transferred through a polymer multilayer structure. The orientation is obtained using three polymer layers, where the uppermost layer shrinks resulting in orientation of the semiconductor film beneath the intermediate layer. The topmost and intermediate polymer films are removed to reveal the oriented surface. The cover shows a crossed-polarizer microscopy image of an oriented regio-regular poly(3-hexylthiophene) film. We present a new technique for orienting polymer semiconductor thin films. In our technique, polymer chains are rigorously oriented without using any mechanical tools and with minimal risk of film contamination. The technique is based on the mechanical force resulting from the in-plane shrinkage exerted by a shrinker (top layer) that is used to orient the semiconductor beneath an intermediate layer; the latter acting as a force mediator. The chain orientation is demonstrated by several techniques such as crossed-polarizer microscopy, atomic force microscopy, grazing-incidence X-ray diffraction, and polarized absorption. The orientation geometry is controlled by the shrinking process and the shrinker area. The semiconductivity of the film only stems from the transistor device structures under study, and the method can therefore be generalized. [source] The new V12 ultra-small-angle neutron scattering and tomography instrument at the Hahn,Meitner InstitutJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 2007M. Strobl The new V12 instrument at the Hahn,Meitner Institute in Berlin is a multiple setup combining several techniques to investigate the internal structure of bulk samples. It consists of two double-crystal diffractometers (DCDs) and an attenuation tomography device operating with monochromatic neutrons. The three instrument parts can be used independently at the same time. The DCDs are mainly used in the ultra-small-angle neutron scattering (USANS) regime, where they overlap the accessible range of small-angle neutron scattering instruments, while tomographic methods collect real-space information on a macroscopic scale. Together they enable structural investigations over six orders of magnitude (50,nm to 5,cm). Scattering and tomographic methods can even be combined by means of diffraction and scattering-enhanced imaging. The sample environment can be varied over a large range of temperatures and pressures for USANS measurements and a polarized USANS option is available. [source] | ||||||||||||||||||||||||||||||||||||||||||||||