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Several Attempts (several + attempt)
Selected AbstractsGlobal hybrid modeling and control of a buck converter: A novel conceptINTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 9 2009Mohammad Hejri Abstract Several attempts have been made to design suitable controllers for DC,DC converters. However, these designs suffer from model inaccuracy or their inability to desirably function in both continuous and discontinuous current modes. This paper presents a novel switching scheme based on hybrid modeling to control a buck converter using mixed logical dynamical (MLD) methodologies. The proposed method is capable of globally controlling the converter in both continuous and discontinuous current modes of operation by considering all constraints in the physical plant such as maximum inductor current and capacitor voltage limits. Different loads and input voltage disturbances are simulated in MATLAB and results are presented to demonstrate the suitability of the controller. The transient and steady-state performance of the closed-loop control over a wide range of operating points shows satisfactory operation of the proposed controller. Copyright © 2008 John Wiley & Sons, Ltd. [source] Excellent response of refractory life-threatening thrombotic thrombocytopenic purpura to cyclosporine treatmentINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 1 2004M. Itälä Summary The introduction of plasma exchange has significantly improved the outcome of thrombotic thrombocytopenic purpura (TTP), and survival has increased from 10 to 80,90%. TTP refractory to plasma exchange therapy, however, is still a therapeutic challenge. We describe here a patient who partially responded to plasma exchange therapy, but remained totally dependent on plasma infusions. Several attempts to discontinue plasma therapy repeatedly lead to relapses. TTP did not response to vincristine, either. After 3 months treatment with plasma therapy, cyclosporine was started. Plasma therapy could be discontinued after 3 weeks on cyclosporine, and serum LDH and blood platelet count were gradually normalized during 2 months. Cyclosporine was tapered off after 6 months treatment, and the patient has stayed in remission ever since. We conclude that cyclosporine is a worthwhile treatment option in patients with refractory TTP. [source] Reducing the effect of parent averages from animal solutions in mixed model equationsJOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 6 2000L. Wu Summary Selection of animals based on their BLUP evaluations from an animal model results in animals that are closely related which leads to increased rates of inbreeding. The tendency for higher inbreeding rates is greater at low heritability values. Several attempts have been made to reduce the impact of parent average breeding values from animals evaluations in order to reduce inbreeding while not sacrificing genetic response. A method that modifies the rules for forming the inverse of the additive genetic relationship matrix for use in best linear unbiased estimation of breeding values via an animal model was developed. This method and several others were compared analytically and empirically, from the perspective of partitioning the animal solutions into contributions from the data, from progeny, and from the parent average. The ratio of genetic progress to average level of inbreeding showed that the modified relationship matrix method was superior to the other methods. Similar results could be obtained by using artificially high heritability in a usual BLUP analysis. Zusammenfassung Die Selektion von Tieren aufgrund ihrer geschätzten BLUP-Zuchtwerte unter einem Tiermodell ergibt verwandte Tiere, was zu gesteigerten Inzuchtraten führt. Einige Versuche wurden unternommen, um die Wirkung des elterlichen Zuchtwertduchschnitts auf die geschätzten Tierzuchtwerte zu reduzieren, um einerseits die Inzucht einzugrenzen, aber andererseits den Zuchtfortschritt nicht zu beeinträchtigen. Es wurde eine Methode entwickelt, welche die Regeln zur Aufstellung der additiven genetischen Verwandtschaftsmatrix im Tiermodell für die BLUP-Zuchtwertschätzung modifiziert. Diese und einige andere Methoden wurden empirisch und analytisch verglichen. Das geschah aus der Sicht, die Lösungen für die Tiereffekte in Bezug auf den Beitrag der Eltern, der Eigenleistung und der Nachkommen aufzuteilen. Das Verhältnis des Zuchtfortschritts zum mittleren Inzuchtniveau zeigte, dass die modifizierte Verwandtschaftsmatrix als Methode allen anderen überlegen war. Ähnliche Ergebnisse konnten erreicht werden, wenn in einer gewöhnlichen BLUP-Analyse der Heritabilitätsparameter künstlich hochgesetzt wird. [source] Congenital hypomyelination neuropathy in a newborn infant: unusual cause of diaphragmatic and vocal cord paralysesJOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 2 2002JS Hahn We report a case of congenital hypomyelination neuropathy presenting at birth. The infant had generalized hypotonia and weakness. There was decreased respiratory effort along with a right phrenic nerve and left vocal cord paralyses. Tongue fasciculations were present. Deep tendon reflexes were absent in the upper extremities and hypoactive (1+) in the lower extremities. Magnetic resonance imaging of the head revealed no intracranial abnormalities, including normal cerebral myelination. Nerve conduction study showed absence of motor and sensory action potentials in the hands when the nerves in the upper limbs were stimulated. A motor response could be elicited only in the proximal leg muscles. Needle electromyography study was normal in the proximal limb muscles, but showed active denervation in the distal muscles of the arm and leg. These findings were thought to be consistent with a length-dependent sensorimotor peripheral polyneuropathy of axonal type with greater denervation of the distal muscles. A biopsy of the quadriceps muscle showed mild variability in fiber diameter, but no group typing or group atrophy. The muscle fibers showed no intrinsic abnormalities. Biopsy of the sural nerve showed scattered axons with very thin myelin sheaths. There was also a nearly complete loss of large diameter myelinated fibers. No onion bulb formations were noted. These findings were thought to be consistent with congenital hypomyelination neuropathy with a component of axonopathy. DNA analysis for identification of previously characterized mutations in the genes MPZ, PMP22, and EGR2 was negative. Several attempts at extubation failed and the infant became increasingly ventilator-dependent with increasing episodes of desaturation and hypercapnea. He also developed increasing weakness and decreased movement of all extremities. He underwent surgery at 2 months of age for placement of a gastrostomy tube and a tracheostomy. He was discharged from the hospital on a ventilator at 6 months of age. The infant was 13 months old at the time of submission of this report. Although he appears cognitively normal, he remains profoundly hypotonic and is on a home ventilator. There was no evidence of progressive weakness. Congenital hypomyelination neuropathy is a rare form of neonatal neuropathy that should be considered in the differential diagnosis of a newborn with profound hypotonia and weakness. It appears to be a heterogeneous disorder with some of the cases being caused by specific genetic mutations. [source] Long-distance movements of the grey-headed flying fox (Pteropus poliocephalus)JOURNAL OF ZOOLOGY, Issue 2 2004Christopher R. Tidemann Abstract The grey-headed flying fox Pteropus poliocephalus, a nationally vulnerable species, is endemic to coastal eastern Australia, from Maryborough, Queensland, through New South Wales to Melbourne, Victoria. Pteropus poliocephalus forages at night, primarily on eucalypt blossom within 50 km of traditional camps (day roosts), usually in dense, riparian vegetation. Several attempts have been made to track long-distance movements of P. poliocephalus across its extensive and climatically highly variable range, but the technology has been inadequate for tracking at the required speed and scale. Satellite tracking was used to monitor movements of a 2-year-old male P. poliocephalus, trapped at the Currie Park camp in the north of the species' range (28°48,S) from January 2000, and another from its most southerly camp, Melbourne (37°50,S), from April 2000. The first flying fox moved camp 50 km noth-east to Dallas Park, where it stayed until March, then transited at least 15 other camps between 28°12,,32°44,S, before returning to Dallas Park in September. The second flying fox remained in Melbourne until July, then transited at least six other camps to 33°44,S, before returning to Melbourne in January 2001. Both animals made round trips of at least 2000 km, traversing >4° latitude, before returning to their camps of origin, while other animals remained. The study suggests that P. poliocephalus is a partial migrant that uses winds to facilitate long-distance movements, and underlines the importance of management at a national scale. [source] Structure and function of the Mur enzymes: development of novel inhibitorsMOLECULAR MICROBIOLOGY, Issue 1 2003Ahmed El Zoeiby Summary One of the biggest challenges for recent medical research is the continuous development of new antibiotics interacting with bacterial essential mechanisms. The machinery for peptidoglycan biosynthesis is a rich source of crucial targets for antibacterial chemotherapy. The cytoplasmic steps of the biosynthesis of peptidoglycan precursor, catalysed by a series of Mur enzymes, are excellent candidates for drug development. There has been growing interest in these bacterial enzymes over the last decade. Many studies attempted to understand the detailed mechanisms and structural features of the key enzymes MurA to MurF. Only MurA is inhibited by a known antibiotic, fosfomycin. Several attempts made to develop novel inhibitors of this pathway are discussed in this review. Three novel inhibitors of MurA were identified recently. 4-Thiazolidinone compounds were designed as MurB inhibitors. Many phosphinic acid derivatives and substrate analogues were identified as inhibitors of the MurC to MurF amino acid ligases. [source] Modification of functional properties of egg-white proteinsMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 6 2003Lydia Campbell Abstract Egg-white proteins are extensively utilised as food ingredients due to their unique functional properties. Several attempts have been made in order to improve the functional properties of egg-white proteins and to identify the optimal formulations for unique food products. Experimental data proves that controlled denaturation of egg-white proteins can have a beneficial impact on various functional applications in the food industry such as emulsifying ability, heat stability, gelation. This review describes the effect of heat-induced denaturation on protein structure and functionality. Studies on the impact of Maillard reaction, which aim to elucidate the structure-function relationship of egg-white proteins, are presented. A novel approach which could be the basis for the development of new methods aiming to improve the functional properties of egg-white proteins is also discussed. [source] Tree plantations for restoration of degraded lands and greening of India: a case study of tree growers' cooperativesNATURAL RESOURCES FORUM, Issue 1 2001K. Balooni Abstract India has over 100 m ha (million hectares) of village common lands. De jure, these lands are owned by the state but, de facto, they are used in common by villagers. Most of the village commons are degraded and denuded and are almost nonproductive. Several attempts have been made in the recent past to restore them through planting of trees by governmental and non-governmental organizations. Tree Growers' Co-operative Societies (TGCS), as an organisational innovation of relatively recent origin, have proved to be more cost-effective than other forms of organisations engaged in greening the village commons in India. This paper attempts to assess the financial viability of tree plantations carried out by three selected TGCS and to distil lessons of their experience useful for policy purposes. The study revealed that plantations founded by the sample TGCS were financially viable, and that the plantations had transformed the desolate village commons into ,green wealth'. The authors conclude that the TGCS have a high potential as an instrument for promoting the afforestation of India's degraded village common lands and thereby improving village economy and the quality of the environment. [source] Electrically adjustable thermotropic windows based on polymer gelsPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 11-12 2003Tamás Gyenes Abstract Several attempts have been made recently in order to develop "Smart" windows, which can moderate light and heat intensities. Based upon the phase transitions of polymer gels, a novel electrically adjustable window, which includes a gel layer, has been developed in our laboratory. Unlike other electrically controlled structures, the optical properties of the gel layer are abruptly modified by the Joule heat of audio frequency AC current. The so-called "gel-glass" becomes opaque when the temperature exceeds a critical value and changes back to its original transparent state when it is cooled down again. This method results in fast control and relatively low operational cost. Two types of gel-glasses,active and passive structures,have been developed and investigated. In this paper, we demonstrate the structural build-up and working of these novel electrically adjustable thermotropic windows. Experimental studies have been made at different frequencies and voltages. The optical properties, as well as the energy balance of the systems, have been reported. Copyright © 2003 John Wiley & Sons, Ltd. [source] Utility of a Peritoneal Dialysis Leukocyte Test Strip in the Diagnosis of PeritonitisARTIFICIAL ORGANS, Issue 6 2002Ramin Sam Abstract: Expeditious diagnosis of peritonitis remains a significant goal in the management of patients maintained on peritoneal dialysis. Several attempts to use leukocyte esterase reagent strips to diagnose peritonitis have been described. In this study we examined the usefulness of a new reagent strip, the PeriScreen Test Strip, in the diagnosis of peritonitis. A series of 72 peritoneal effluent samples obtained from 22 maintenance peritoneal dialysis patients is reported. In this study, the test strips had a sensitivity of 100% and a specificity of 98.3% as compared to an abnormal leukocyte count. Thus, in the diagnosis of peritonitis we believe that the PeriScreen Test Strip can be used as a simple bedside screening test to exclude peritonitis in peritoneal dialysis patients. [source] A Semi-Lagrangian CIP Fluid Solver without Dimensional SplittingCOMPUTER GRAPHICS FORUM, Issue 2 2008Doyub Kim Abstract In this paper, we propose a new constrained interpolation profile (CIP) method that is stable and accurate but requires less amount of computation compared to existing CIP-based solvers. CIP is a high-order fluid advection solver that can reproduce rich details of fluids. It has third-order accuracy but its computation is performed over a compact stencil. These advantageous features of CIP are, however, diluted by the following two shortcomings: (1) CIP contains a defect in the utilization of the grid data, which makes the method suitable only for simulations with a tight CFL restriction; and (2) CIP does not guarantee unconditional stability. There have been several attempts to fix these problems in CIP, but they have been only partially successful. The solutions that fixed both problems ended up introducing other undesirable features, namely increased computation time and/or reduced accuracy. This paper proposes a novel modification of the original CIP method that fixes all of the above problems without increasing the computational load or reducing the accuracy. Both quantitative and visual experiments were performed to test the performance of the new CIP in comparison to existing fluid solvers. The results show that the proposed method brings significant improvements in both accuracy and speed. [source] The quest for a null model for macroecological patterns: geometry of species distributions at multiple spatial scalesECOLOGY LETTERS, Issue 8 2008David Storch Abstract There have been several attempts to build a unified framework for macroecological patterns. However, these have mostly been based either on questionable assumptions or have had to be parameterized to obtain realistic predictions. Here, we propose a new model explicitly considering patterns of aggregated species distributions on multiple spatial scales, the property which lies behind all spatial macroecological patterns, using the idea we term ,generalized fractals'. Species' spatial distributions were modelled by a random hierarchical process in which the original ,habitat' patches were randomly replaced by sets of smaller patches nested within them, and the statistical properties of modelled species assemblages were compared with macroecological patterns in observed bird data. Without parameterization based on observed patterns, this simple model predicts realistic patterns of species abundance, distribution and diversity, including fractal-like spatial distributions, the frequency distribution of species occupancies/abundances and the species,area relationship. Although observed macroecological patterns may differ in some quantitative properties, our concept of random hierarchical aggregation can be considered as an appropriate null model of fundamental macroecological patterns which can potentially be modified to accommodate ecologically important variables. [source] Perceived need for emergency medicine training in Pakistan: A survey of medical education leadershipEMERGENCY MEDICINE AUSTRALASIA, Issue 2 2009Junaid A Razzak Abstract Objective: To assess the perception of leaders of the academic medical institutions regarding the need for specialty training in emergency medicine. Methods: A cross-sectional survey was conducted in all medical colleges of Pakistan in September 2005. Our sample included all academic leaders of recognized medical colleges in Pakistan. A questionnaire was designed and sent (mailed and faxed) to vice chancellors, deans, principals or medical directors of the institutions. Reminders were sent through faxes and emails wherever available, followed by phone calls if responses were not available after several attempts. Results: At the time of study, there were 39 medical colleges recognized by Pakistan Medical and Dental Council. Of these, responses were received from 26 teaching institutions in the country. A majority of the respondents (85%) were not satisfied with the care provided in the ED of their primary teaching hospital, and three-fourth (74%) thought that doctors specialized in other disciplines, like internal medicine and family medicine, cannot adequately manage all emergencies. When asked if Pakistan should have a separate residency training programme in emergency medicine, 96% responded in affirmative, and many (85%) thought that they will start a residency programme in emergency medicine if it was approved as a separate specialty. Conclusion: This survey shows significant support for a separate local training programme for emergency medicine in the country. [source] Azide,Tetrazole Ring-Chain Isomerism in Polyazido-1,3,5-triazines, Triazido- s -heptazine, and DiazidotetrazinesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 11 2006Anton Hammerl Abstract The azide,tetrazole isomerism in several polyazido-1,3,5-triazines, triazido- sym -heptazine, and some diazido-1,2,4,5-tetrazines was investigated by ab initio quantum chemical methods in order to determine whether the polyazides are suitable starting materials for the synthesis of the isomeric tetrazoles. The effects of solvation in CCl4, DMSO and water on this isomerism were included using the self consistent reaction field (SCRF) method. The effect of amino- and nitrosubstituents on the azide,tetrazole isomerism was also examined. In the gas phase all investigated polyazidoheterocycles do not cyclize to form tetrazoles. An electron-donating amino group favors the ring closure to tetrazoles, whereas an electron-withdrawing nitro group favors the azides. Solvation in polar solvents favors the formation of a tetrazole ring system due to higher charge separation in the tetrazole ring system, but for all polyazido-1,3,5-triazines, including triazido- s -heptazine, the effects of solvation are not strong enough to shift the equilibrium to the tetrazole side, which explains why several attempts to detect these compounds have failed. The monotetetrazoles of diazidotetrazine and bis(azido)azo-1,2,4,5-tetrazine and the ditetrazole of bis(azido)hydrazo-1,2,4,5-tetrazine are the minimum energy species in DMSO and water. Thus we predict that the diazidoazo- and hydrazotetrazines will readily cyclize to the tetrazoles in polar solvents. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Forgotten faces: regional history and regional portraiture*HISTORICAL RESEARCH, Issue 199 2005Sir Roy Strong This article, a revised version of the fourth Marc Fitch lecture, examines the fate of regional portraits, many of which have been lost over the past century or more. The breaking up of local collections and the widespread demolition of country houses , virtually unremarked until the nineteen-seventies , meant the loss of a valuable source for regional history. While several attempts have been made by enthusiastic individuals or local historians and archivists to catalogue such portraits, a strong case remains for a broader survey of regional portraits. [source] The effectiveness and efficiency of corporate insolvency law,part twoINTERNATIONAL INSOLVENCY REVIEW, Issue 3 2009Karin Luttikhuis Little empirical research has been done in the Netherlands (or internationally) into the effect of corporate insolvency proceedings. The Dutch legislature has made several attempts in the past decades to revise the current Dutch Bankruptcy Act (Faillissementswet) of 1893, while almost nothing is known about the effectiveness and efficiency of the Dutch corporate insolvency law. I have studied the effectiveness of the current Dutch insolvency law and of European Directive 2001/23/EC which is incorporated in this law, on the basis of theoretical and large-scale empirical research. The study concerned all 4167 of the corporate insolvencies that ended in 2004. In the first part of this Article (International Insolvency Review, Volume 17, 3, Winter 2008, pp. 189,209), the research results showed that the Dutch Bankruptcy Act achieved the goals set on it only to a limited degree and that the informal restructuring procedure is of great social importance. In this second part, I concentrate on the conditions imposed by European Directive 2001/23/EC on the European national legislatures to protect employees' rights: automatic transfer of employment contracts in the event of transfers as part of insolvency proceedings, together with measures to prevent misuse of insolvency proceedings in such a way as to deprive employees of the rights provided for in this European Directive. The study shows that, in the Netherlands, not applying automatic transfer of employment contracts when an undertaking or business is transferred as part of an insolvency proceeding does not result in large-scale misuse of insolvency law. It appears that automatic transfer of employment contracts outside insolvency proceedings can actually impede the informal restructuring of financially unsound companies. These surprising results are interesting for corporate insolvency proceedings worldwide. Copyright © 2009 John Wiley & Sons, Ltd. [source] Dental follicle infection following a dog biteINTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY, Issue 2 2006G. WRIGHT Summary. Animal bite wounds and their subsequent infection are relatively common. Incidence rates for dog bites are significantly higher among children aged 0,9 years, especially among boys. Although bite wounds may initially look innocuous, they frequently lead to serious infection with a potential for life-threatening complications. The microbiology of dog bite wounds is usually polymicrobial, typically including anaerobes, Staphylococcus aureus and Pasteurella species. A case is described of a 22-month-old boy who, subsequent to a dog bite over the left maxilla, suffered infection of the dental follicle of the primary maxillary canine with Pasteurella multocida. The infection proved difficult to treat, requiring several attempts at incision and drainage of the abscess together with systemic antibiotics, and resulted in the eventual loss of the tooth. [source] Androgen Receptor Expression Helps to Differentiate BCC From Trichoblastoma and TrichoepitheliomaJOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2005L. Izikson Histological differentiation between basal cell carcinoma and benign trichoblastic neoplasms such as trichoepithelioma and trichoblastoma can be difficult on small biopsies. Therefore, several attempts have been made to identify immunohistochemical differences between these entities. Recent studies showed androgen receptor expression in a number of mature epithelial structures in the skin and in epithelial neoplasms including basal cell carcinoma. In contrast, androgen receptor expression was absent in mature hair follicles or the few trichogenic neoplasms studied to date. These findings suggested that androgen receptor expression might be a useful adjunct in the histological differential diagnosis between basal cell carcinoma and benign trichoblastic neoplasms. Therefore, we performed immunohistochemical analysis of androgen receptor expression in 32 basal cell carcinomas and 10 benign trichoblastic tumors (6 trichoepitheliomas and 4 trichoblastomas). In our study, expression of androgen receptor was detected in 78% of basal cell carcinomas. None of the trichoblastic tumors showed any androgen receptor immunoreactivity. These results confirm the lack of androgen receptor expression in benign trichoblastic neoplasms and indicate that finding of androgen receptor expression points to basal cell carcinoma as the most likely diagnosis. [source] Synthesis of A,[1-42] and its derivatives with improved efficiencyJOURNAL OF PEPTIDE SCIENCE, Issue 2 2007Márta Zarándi Abstract It has been proved that the principal component of senile plaques is aggregates of ,-amyloid peptide (A,) in cases of one of the most common forms of age-related neurodegenerative disorders, Alzheimer's disease (AD). Although the synthetic methods for the synthesis of A, peptides have been developed since their first syntheses, A,[1-42] is still problematic to prepare. The highly hydrophobic composition of A,[1-42] results in aggregation between resin-bound peptide chains or intrachain aggregation which leads to a decrease in the rates of deprotection and repetitive incomplete coupling reactions during 9-flurenylmethoxycarbonyl (Fmoc) synthesis. In order to avoid aggregation and/or disrupt internal aggregation during stepwise Fmoc solid phase synthesis and to improve the quality of crude products, several attempts have been made. Since highly pure A, peptides in large quantities are used in biological experiments, we wanted to develop a method for a rational synthesis of human A,[1-42] with high purity and adequate yield. This paper reports a convenient methodology with a novel solvent system for the synthesis of A,[1-42], its N -terminally truncated derivatives A,[4-42] and A,[5-42], and A,[1-42] labeled with 7-amino-4-methyl-3-coumarinylacetic acid (AMCA) at the N -terminus using Fmoc strategy. The use of 10% anisole in Dimethylformamide/Dichloromethane (DMF/DCM) can substantially improve the purity and yield of crude A,[1-42] and has been shown to be an optimal coupling condition for the synthesis of A,[1-42]. Anisole is a cheap and simple aid in the synthesis of ,difficult sequences' where other solvents are less successful in the prevention of aggregation during the synthesis. Copyright © 2006 European Peptide Society and John Wiley & Sons, Ltd. [source] Competitive Institution Building: The PT and Participatory Budgeting in Rio Grande do SulLATIN AMERICAN POLITICS AND SOCIETY, Issue 3 2006Benjamin Goldfrank ABSTRACT In the late 1990s, the Workers' Party (PT) government of the Brazilian state of Rio Grande do Sul introduced participatory budgeting, a process in which citizens establish annual investment priorities in public assemblies. This innovation was one of several attempts by incumbent parties to structure political conflict using budget institutions. The character of participatory budgeting is most evident in its policymaking processes and policy outcomes. The process circumvented legislative arenas where opponents held a majority, privileged participation by the PT's voter base, and reached into opposition strongholds. The outcomes favored the interests of potential supporters among poor and middle-class voters. The political project proved vulnerable to its own raised expectations: it failed to sustain the image of clean government; brought tax increases along with fiscal insecurity; and left unfulfilled the participants' expectations for targeted investments. This article highlights the role of participatory budgeting, indeed all budgeting, in partisan actors' institutional choices. [source] Translating 5-HT4 receptor pharmacologyNEUROGASTROENTEROLOGY & MOTILITY, Issue 12 2009G. J. Sanger Abstract, Since metoclopramide was first described (in 1964) there have been several attempts to develop compounds which retained gastrointestinal prokinetic activity (via 5-HT4 receptor activation) but without the limiting side effects associated with dopamine D2 receptor antagonism. Early compounds (mosapride, cisapride, renzapride, tegaserod) were identified before several of the 5-HT receptors were even described (including 5-HT4 and 5-HT2B), whereas prucalopride came later. Several compounds were hampered by non-selectivity, introducing cardiac liability (cisapride: activity at human Ether-a-go-go Related Gene) or potentially, a reduced intestinal prokinetic activity caused by activity at a second 5-HT receptor (renzapride: antagonism at the 5-HT3 receptor; tegaserod: antagonism at the 5-HT2B receptor). Poor intrinsic activity at gastrointestinal 5-HT4 receptors has also been an issue (mosapride, tegaserod). Perhaps prucalopride has now achieved the profile of good selectivity of action and high intrinsic activity at intestinal 5-HT4 receptors, without clinically-meaningful actions on 5-HT4 receptors in the heart. The progress of this compound for treatment of chronic constipation, as well as competitor molecules such as ATI-7505 and TD-5108, will now be followed with interest as each attempts to differentiate themselves from each other. Perhaps at last, 5-HT4 receptor agonists are being given the chance to show what they can do. [source] Iraq struggles to pass new oil lawOIL AND ENERGY TRENDS, Issue 9 2007Article first published online: 11 SEP 200 Amid the continuing chaos in Iraq, the government is trying to obtain agreement on a new oil law covering upstream investment and the sharing of oil revenues amongst the 18 provinces of the country. Despite several attempts to draw up new legislation, the government has been unable to obtain sufficient agreement among the various ethnic, religious and other groups to obtain a sufficient majority to allow the country's parliament to pass any new law covering the petroleum industry. [source] Secondary infertility as a late complication of vesico-amniotic shunt therapyPRENATAL DIAGNOSIS, Issue 4 2007M. M. Kamphuis Abstract Objective Vesico-amniotic shunting can be used for the treatment of fetal obstructive uropathy. However, the procedure is associated with a significant risk of complications. We report a case of a complicated vesico-amniotic placement, where a vesico-amniotic shunt ultimately resulted in, fortunately reversible, infertility. Case A 36-year-old multigravida was referred to our center at 13 weeks' gestation for the evaluation of fetal lower urinary obstruction. A vesico-amniotic shunt placement requiring several attempts was performed. A few weeks later premature rupture of the membranes occurred. At the request of the parents, the pregnancy was terminated at 22 weeks'gestation. The patient visited us again for secondary infertility, which turned out to be caused by a shunt left behind in the uterus, acting as an IUD. After hysteroscopic removal, she soon became pregnant again. Conclusion This case illustrates the importance of careful documentation relating to each and every operation, of all materials used and what was retained in the patient. At delivery, obstetric staff should be completely aware of the prenatal treatment procedures performed, to ensure that no foreign objects are left by oversight, inside the patient's body. Copyright © 2007 John Wiley & Sons, Ltd. [source] Computer-assisted implantology: historical background and potential outcomes,a reviewTHE INTERNATIONAL JOURNAL OF MEDICAL ROBOTICS AND COMPUTER ASSISTED SURGERY, Issue 2 2008Abbas Azari Abstract Background The accurate transfer of preoperatively determined implant positions to the patient mouth is very beneficial to the dental practitioner as well as patients. The objective of this paper was to review the gradual development of computer-assisted implant surgery. Methods All of the major data sources including unpublished data in the internet are considered Results and Conclusions Computer-assisted/-guided/-aided implantology has been founded to overcome the errors encountered during implant osteotomies and to position the implants more precisely. The protocols followed by this sophisticated technique are based upon the advocated concept of prosthetic-driven implantology and CT-scan analysis recently approved. Although several attempts have been made to improve this approach more and more, little has been done regarding the patient's demands, including cost. The inherent complexity of the techniques and materials utilized necessitates several degrees of training before attempting treatment and must be taken into account. Copyright © 2008 John Wiley & Sons, Ltd. [source] The etiology of otosclerosis: A combination of genes and environment,THE LARYNGOSCOPE, Issue 6 2010Isabelle Schrauwen MSc Abstract Otosclerosis is a common form of hearing loss characterized by abnormal bone remodeling in the otic capsule. It is a complex genetic disease, caused by a combination of genetic and environmental factors. During the past decade, several attempts have been made to identify factors for otosclerosis. This review provides an overview of the current understanding of the etiology of otosclerosis and describes the genetic and environmental factors that have been implicated in the disease. Environmental factors include fluoride and viral factors, particularly measles. Genetic association studies for otosclerosis have reported several associations of genetic variants that influence the risk of disease, mainly involving bone remodeling pathways, although their individual risk contributions are small. Rare monogenic forms of otosclerosis also exist, which are caused by a mutation in a single gene leading to a clear familial segregation of the disease. Linkage analysis of large otosclerosis families has led to the identification of seven loci, and recently evidence was found that T cell receptor beta is a gene responsible for familial otosclerosis, suggesting an underlying immunological pathway. However, this might also represent an autoimmune process, a hypothesis that is supported by other data as well. In conclusion, a variety of pathways have been identified to be involved in the development of otosclerosis, showing that distinct mechanisms involving both genetic and environmental risk factors can influence and contribute to a similar disease outcome. [source] Techniques and predictive models to improve prostate cancer detection,CANCER, Issue S13 2009Michael P. Herman MD Abstract The use of prostate-specific antigen (PSA) as a screening test remains controversial. There have been several attempts to refine PSA measurements to improve its predictive value. These modifications, including PSA density, PSA kinetics, and the measurement of PSA isoforms, have met with limited success. Therefore, complex statistical and computational models have been created to assess an individual's risk of prostate cancer more accurately. In this review, the authors examined the methods used to modify PSA as well as various predictive models used in prostate cancer detection. They described the mathematical underpinnings of these techniques along with their intrinsic strengths and weaknesses, and they assessed the accuracy of these methods, which have been shown to be better than physicians' judgment at predicting a man's risk of cancer. Without understanding the design and limitations of these methods, they can be applied inappropriately, leading to incorrect conclusions. These models are important components in counseling patients on their risk of prostate cancer and also help in the design of clinical trials by stratifying patients into different risk categories. Thus, it is incumbent on both clinicians and researchers to become familiar with these tools. Cancer 2009;115(13 suppl):3085,99. © 2009 American Cancer Society. [source] | |||||||||||||||||||||||||